Spelling fixes.
[emacs.git] / src / alloc.c
blobd4e24b6244b590a8a2f3b95801dd301045ae0c49
1 /* Storage allocation and gc for GNU Emacs Lisp interpreter.
3 Copyright (C) 1985-1986, 1988, 1993-1995, 1997-2014 Free Software
4 Foundation, Inc.
6 This file is part of GNU Emacs.
8 GNU Emacs is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
21 #include <config.h>
23 #include <stdio.h>
24 #include <limits.h> /* For CHAR_BIT. */
26 #ifdef ENABLE_CHECKING
27 #include <signal.h> /* For SIGABRT. */
28 #endif
30 #ifdef HAVE_PTHREAD
31 #include <pthread.h>
32 #endif
34 #include "lisp.h"
35 #include "process.h"
36 #include "intervals.h"
37 #include "puresize.h"
38 #include "character.h"
39 #include "buffer.h"
40 #include "window.h"
41 #include "keyboard.h"
42 #include "frame.h"
43 #include "blockinput.h"
44 #include "termhooks.h" /* For struct terminal. */
45 #ifdef HAVE_WINDOW_SYSTEM
46 #include TERM_HEADER
47 #endif /* HAVE_WINDOW_SYSTEM */
49 #include <verify.h>
51 #if (defined ENABLE_CHECKING \
52 && defined HAVE_VALGRIND_VALGRIND_H \
53 && !defined USE_VALGRIND)
54 # define USE_VALGRIND 1
55 #endif
57 #if USE_VALGRIND
58 #include <valgrind/valgrind.h>
59 #include <valgrind/memcheck.h>
60 static bool valgrind_p;
61 #endif
63 /* GC_CHECK_MARKED_OBJECTS means do sanity checks on allocated objects.
64 Doable only if GC_MARK_STACK. */
65 #if ! GC_MARK_STACK
66 # undef GC_CHECK_MARKED_OBJECTS
67 #endif
69 /* GC_MALLOC_CHECK defined means perform validity checks of malloc'd
70 memory. Can do this only if using gmalloc.c and if not checking
71 marked objects. */
73 #if (defined SYSTEM_MALLOC || defined DOUG_LEA_MALLOC \
74 || defined GC_CHECK_MARKED_OBJECTS)
75 #undef GC_MALLOC_CHECK
76 #endif
78 #include <unistd.h>
79 #include <fcntl.h>
81 #ifdef USE_GTK
82 # include "gtkutil.h"
83 #endif
84 #ifdef WINDOWSNT
85 #include "w32.h"
86 #include "w32heap.h" /* for sbrk */
87 #endif
89 #ifdef DOUG_LEA_MALLOC
91 #include <malloc.h>
93 /* Specify maximum number of areas to mmap. It would be nice to use a
94 value that explicitly means "no limit". */
96 #define MMAP_MAX_AREAS 100000000
98 #endif /* not DOUG_LEA_MALLOC */
100 /* Mark, unmark, query mark bit of a Lisp string. S must be a pointer
101 to a struct Lisp_String. */
103 #define MARK_STRING(S) ((S)->size |= ARRAY_MARK_FLAG)
104 #define UNMARK_STRING(S) ((S)->size &= ~ARRAY_MARK_FLAG)
105 #define STRING_MARKED_P(S) (((S)->size & ARRAY_MARK_FLAG) != 0)
107 #define VECTOR_MARK(V) ((V)->header.size |= ARRAY_MARK_FLAG)
108 #define VECTOR_UNMARK(V) ((V)->header.size &= ~ARRAY_MARK_FLAG)
109 #define VECTOR_MARKED_P(V) (((V)->header.size & ARRAY_MARK_FLAG) != 0)
111 /* Default value of gc_cons_threshold (see below). */
113 #define GC_DEFAULT_THRESHOLD (100000 * word_size)
115 /* Global variables. */
116 struct emacs_globals globals;
118 /* Number of bytes of consing done since the last gc. */
120 EMACS_INT consing_since_gc;
122 /* Similar minimum, computed from Vgc_cons_percentage. */
124 EMACS_INT gc_relative_threshold;
126 /* Minimum number of bytes of consing since GC before next GC,
127 when memory is full. */
129 EMACS_INT memory_full_cons_threshold;
131 /* True during GC. */
133 bool gc_in_progress;
135 /* True means abort if try to GC.
136 This is for code which is written on the assumption that
137 no GC will happen, so as to verify that assumption. */
139 bool abort_on_gc;
141 /* Number of live and free conses etc. */
143 static EMACS_INT total_conses, total_markers, total_symbols, total_buffers;
144 static EMACS_INT total_free_conses, total_free_markers, total_free_symbols;
145 static EMACS_INT total_free_floats, total_floats;
147 /* Points to memory space allocated as "spare", to be freed if we run
148 out of memory. We keep one large block, four cons-blocks, and
149 two string blocks. */
151 static char *spare_memory[7];
153 /* Amount of spare memory to keep in large reserve block, or to see
154 whether this much is available when malloc fails on a larger request. */
156 #define SPARE_MEMORY (1 << 14)
158 /* Initialize it to a nonzero value to force it into data space
159 (rather than bss space). That way unexec will remap it into text
160 space (pure), on some systems. We have not implemented the
161 remapping on more recent systems because this is less important
162 nowadays than in the days of small memories and timesharing. */
164 EMACS_INT pure[(PURESIZE + sizeof (EMACS_INT) - 1) / sizeof (EMACS_INT)] = {1,};
165 #define PUREBEG (char *) pure
167 /* Pointer to the pure area, and its size. */
169 static char *purebeg;
170 static ptrdiff_t pure_size;
172 /* Number of bytes of pure storage used before pure storage overflowed.
173 If this is non-zero, this implies that an overflow occurred. */
175 static ptrdiff_t pure_bytes_used_before_overflow;
177 /* True if P points into pure space. */
179 #define PURE_POINTER_P(P) \
180 ((uintptr_t) (P) - (uintptr_t) purebeg <= pure_size)
182 /* Index in pure at which next pure Lisp object will be allocated.. */
184 static ptrdiff_t pure_bytes_used_lisp;
186 /* Number of bytes allocated for non-Lisp objects in pure storage. */
188 static ptrdiff_t pure_bytes_used_non_lisp;
190 /* If nonzero, this is a warning delivered by malloc and not yet
191 displayed. */
193 const char *pending_malloc_warning;
195 /* Maximum amount of C stack to save when a GC happens. */
197 #ifndef MAX_SAVE_STACK
198 #define MAX_SAVE_STACK 16000
199 #endif
201 /* Buffer in which we save a copy of the C stack at each GC. */
203 #if MAX_SAVE_STACK > 0
204 static char *stack_copy;
205 static ptrdiff_t stack_copy_size;
207 /* Copy to DEST a block of memory from SRC of size SIZE bytes,
208 avoiding any address sanitization. */
210 static void * ATTRIBUTE_NO_SANITIZE_ADDRESS
211 no_sanitize_memcpy (void *dest, void const *src, size_t size)
213 if (! ADDRESS_SANITIZER)
214 return memcpy (dest, src, size);
215 else
217 size_t i;
218 char *d = dest;
219 char const *s = src;
220 for (i = 0; i < size; i++)
221 d[i] = s[i];
222 return dest;
226 #endif /* MAX_SAVE_STACK > 0 */
228 static Lisp_Object Qconses;
229 static Lisp_Object Qsymbols;
230 static Lisp_Object Qmiscs;
231 static Lisp_Object Qstrings;
232 static Lisp_Object Qvectors;
233 static Lisp_Object Qfloats;
234 static Lisp_Object Qintervals;
235 static Lisp_Object Qbuffers;
236 static Lisp_Object Qstring_bytes, Qvector_slots, Qheap;
237 static Lisp_Object Qgc_cons_threshold;
238 Lisp_Object Qautomatic_gc;
239 Lisp_Object Qchar_table_extra_slots;
241 /* Hook run after GC has finished. */
243 static Lisp_Object Qpost_gc_hook;
245 static void mark_terminals (void);
246 static void gc_sweep (void);
247 static Lisp_Object make_pure_vector (ptrdiff_t);
248 static void mark_buffer (struct buffer *);
250 #if !defined REL_ALLOC || defined SYSTEM_MALLOC
251 static void refill_memory_reserve (void);
252 #endif
253 static void compact_small_strings (void);
254 static void free_large_strings (void);
255 extern Lisp_Object which_symbols (Lisp_Object, EMACS_INT) EXTERNALLY_VISIBLE;
257 /* When scanning the C stack for live Lisp objects, Emacs keeps track of
258 what memory allocated via lisp_malloc and lisp_align_malloc is intended
259 for what purpose. This enumeration specifies the type of memory. */
261 enum mem_type
263 MEM_TYPE_NON_LISP,
264 MEM_TYPE_BUFFER,
265 MEM_TYPE_CONS,
266 MEM_TYPE_STRING,
267 MEM_TYPE_MISC,
268 MEM_TYPE_SYMBOL,
269 MEM_TYPE_FLOAT,
270 /* Since all non-bool pseudovectors are small enough to be
271 allocated from vector blocks, this memory type denotes
272 large regular vectors and large bool pseudovectors. */
273 MEM_TYPE_VECTORLIKE,
274 /* Special type to denote vector blocks. */
275 MEM_TYPE_VECTOR_BLOCK,
276 /* Special type to denote reserved memory. */
277 MEM_TYPE_SPARE
280 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
282 /* A unique object in pure space used to make some Lisp objects
283 on free lists recognizable in O(1). */
285 static Lisp_Object Vdead;
286 #define DEADP(x) EQ (x, Vdead)
288 #ifdef GC_MALLOC_CHECK
290 enum mem_type allocated_mem_type;
292 #endif /* GC_MALLOC_CHECK */
294 /* A node in the red-black tree describing allocated memory containing
295 Lisp data. Each such block is recorded with its start and end
296 address when it is allocated, and removed from the tree when it
297 is freed.
299 A red-black tree is a balanced binary tree with the following
300 properties:
302 1. Every node is either red or black.
303 2. Every leaf is black.
304 3. If a node is red, then both of its children are black.
305 4. Every simple path from a node to a descendant leaf contains
306 the same number of black nodes.
307 5. The root is always black.
309 When nodes are inserted into the tree, or deleted from the tree,
310 the tree is "fixed" so that these properties are always true.
312 A red-black tree with N internal nodes has height at most 2
313 log(N+1). Searches, insertions and deletions are done in O(log N).
314 Please see a text book about data structures for a detailed
315 description of red-black trees. Any book worth its salt should
316 describe them. */
318 struct mem_node
320 /* Children of this node. These pointers are never NULL. When there
321 is no child, the value is MEM_NIL, which points to a dummy node. */
322 struct mem_node *left, *right;
324 /* The parent of this node. In the root node, this is NULL. */
325 struct mem_node *parent;
327 /* Start and end of allocated region. */
328 void *start, *end;
330 /* Node color. */
331 enum {MEM_BLACK, MEM_RED} color;
333 /* Memory type. */
334 enum mem_type type;
337 /* Base address of stack. Set in main. */
339 Lisp_Object *stack_base;
341 /* Root of the tree describing allocated Lisp memory. */
343 static struct mem_node *mem_root;
345 /* Lowest and highest known address in the heap. */
347 static void *min_heap_address, *max_heap_address;
349 /* Sentinel node of the tree. */
351 static struct mem_node mem_z;
352 #define MEM_NIL &mem_z
354 static struct mem_node *mem_insert (void *, void *, enum mem_type);
355 static void mem_insert_fixup (struct mem_node *);
356 static void mem_rotate_left (struct mem_node *);
357 static void mem_rotate_right (struct mem_node *);
358 static void mem_delete (struct mem_node *);
359 static void mem_delete_fixup (struct mem_node *);
360 static struct mem_node *mem_find (void *);
362 #endif /* GC_MARK_STACK || GC_MALLOC_CHECK */
364 #ifndef DEADP
365 # define DEADP(x) 0
366 #endif
368 /* Recording what needs to be marked for gc. */
370 struct gcpro *gcprolist;
372 /* Addresses of staticpro'd variables. Initialize it to a nonzero
373 value; otherwise some compilers put it into BSS. */
375 enum { NSTATICS = 2048 };
376 static Lisp_Object *staticvec[NSTATICS] = {&Vpurify_flag};
378 /* Index of next unused slot in staticvec. */
380 static int staticidx;
382 static void *pure_alloc (size_t, int);
384 /* Return X rounded to the next multiple of Y. Arguments should not
385 have side effects, as they are evaluated more than once. Assume X
386 + Y - 1 does not overflow. Tune for Y being a power of 2. */
388 #define ROUNDUP(x, y) ((y) & ((y) - 1) \
389 ? ((x) + (y) - 1) - ((x) + (y) - 1) % (y) \
390 : ((x) + (y) - 1) & ~ ((y) - 1))
392 /* Return PTR rounded up to the next multiple of ALIGNMENT. */
394 static void *
395 ALIGN (void *ptr, int alignment)
397 return (void *) ROUNDUP ((uintptr_t) ptr, alignment);
400 static void
401 XFLOAT_INIT (Lisp_Object f, double n)
403 XFLOAT (f)->u.data = n;
407 /************************************************************************
408 Malloc
409 ************************************************************************/
411 /* Function malloc calls this if it finds we are near exhausting storage. */
413 void
414 malloc_warning (const char *str)
416 pending_malloc_warning = str;
420 /* Display an already-pending malloc warning. */
422 void
423 display_malloc_warning (void)
425 call3 (intern ("display-warning"),
426 intern ("alloc"),
427 build_string (pending_malloc_warning),
428 intern ("emergency"));
429 pending_malloc_warning = 0;
432 /* Called if we can't allocate relocatable space for a buffer. */
434 void
435 buffer_memory_full (ptrdiff_t nbytes)
437 /* If buffers use the relocating allocator, no need to free
438 spare_memory, because we may have plenty of malloc space left
439 that we could get, and if we don't, the malloc that fails will
440 itself cause spare_memory to be freed. If buffers don't use the
441 relocating allocator, treat this like any other failing
442 malloc. */
444 #ifndef REL_ALLOC
445 memory_full (nbytes);
446 #else
447 /* This used to call error, but if we've run out of memory, we could
448 get infinite recursion trying to build the string. */
449 xsignal (Qnil, Vmemory_signal_data);
450 #endif
453 /* A common multiple of the positive integers A and B. Ideally this
454 would be the least common multiple, but there's no way to do that
455 as a constant expression in C, so do the best that we can easily do. */
456 #define COMMON_MULTIPLE(a, b) \
457 ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
459 #ifndef XMALLOC_OVERRUN_CHECK
460 #define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
461 #else
463 /* Check for overrun in malloc'ed buffers by wrapping a header and trailer
464 around each block.
466 The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
467 followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
468 block size in little-endian order. The trailer consists of
469 XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
471 The header is used to detect whether this block has been allocated
472 through these functions, as some low-level libc functions may
473 bypass the malloc hooks. */
475 #define XMALLOC_OVERRUN_CHECK_SIZE 16
476 #define XMALLOC_OVERRUN_CHECK_OVERHEAD \
477 (2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
479 /* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
480 hold a size_t value and (2) the header size is a multiple of the
481 alignment that Emacs needs for C types and for USE_LSB_TAG. */
482 #define XMALLOC_BASE_ALIGNMENT \
483 alignof (union { long double d; intmax_t i; void *p; })
485 #if USE_LSB_TAG
486 # define XMALLOC_HEADER_ALIGNMENT \
487 COMMON_MULTIPLE (GCALIGNMENT, XMALLOC_BASE_ALIGNMENT)
488 #else
489 # define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
490 #endif
491 #define XMALLOC_OVERRUN_SIZE_SIZE \
492 (((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
493 + XMALLOC_HEADER_ALIGNMENT - 1) \
494 / XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
495 - XMALLOC_OVERRUN_CHECK_SIZE)
497 static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
498 { '\x9a', '\x9b', '\xae', '\xaf',
499 '\xbf', '\xbe', '\xce', '\xcf',
500 '\xea', '\xeb', '\xec', '\xed',
501 '\xdf', '\xde', '\x9c', '\x9d' };
503 static char const xmalloc_overrun_check_trailer[XMALLOC_OVERRUN_CHECK_SIZE] =
504 { '\xaa', '\xab', '\xac', '\xad',
505 '\xba', '\xbb', '\xbc', '\xbd',
506 '\xca', '\xcb', '\xcc', '\xcd',
507 '\xda', '\xdb', '\xdc', '\xdd' };
509 /* Insert and extract the block size in the header. */
511 static void
512 xmalloc_put_size (unsigned char *ptr, size_t size)
514 int i;
515 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
517 *--ptr = size & ((1 << CHAR_BIT) - 1);
518 size >>= CHAR_BIT;
522 static size_t
523 xmalloc_get_size (unsigned char *ptr)
525 size_t size = 0;
526 int i;
527 ptr -= XMALLOC_OVERRUN_SIZE_SIZE;
528 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
530 size <<= CHAR_BIT;
531 size += *ptr++;
533 return size;
537 /* Like malloc, but wraps allocated block with header and trailer. */
539 static void *
540 overrun_check_malloc (size_t size)
542 register unsigned char *val;
543 if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
544 emacs_abort ();
546 val = malloc (size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
547 if (val)
549 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
550 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
551 xmalloc_put_size (val, size);
552 memcpy (val + size, xmalloc_overrun_check_trailer,
553 XMALLOC_OVERRUN_CHECK_SIZE);
555 return val;
559 /* Like realloc, but checks old block for overrun, and wraps new block
560 with header and trailer. */
562 static void *
563 overrun_check_realloc (void *block, size_t size)
565 register unsigned char *val = (unsigned char *) block;
566 if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
567 emacs_abort ();
569 if (val
570 && memcmp (xmalloc_overrun_check_header,
571 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
572 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
574 size_t osize = xmalloc_get_size (val);
575 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
576 XMALLOC_OVERRUN_CHECK_SIZE))
577 emacs_abort ();
578 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
579 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
580 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
583 val = realloc (val, size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
585 if (val)
587 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
588 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
589 xmalloc_put_size (val, size);
590 memcpy (val + size, xmalloc_overrun_check_trailer,
591 XMALLOC_OVERRUN_CHECK_SIZE);
593 return val;
596 /* Like free, but checks block for overrun. */
598 static void
599 overrun_check_free (void *block)
601 unsigned char *val = (unsigned char *) block;
603 if (val
604 && memcmp (xmalloc_overrun_check_header,
605 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
606 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
608 size_t osize = xmalloc_get_size (val);
609 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
610 XMALLOC_OVERRUN_CHECK_SIZE))
611 emacs_abort ();
612 #ifdef XMALLOC_CLEAR_FREE_MEMORY
613 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
614 memset (val, 0xff, osize + XMALLOC_OVERRUN_CHECK_OVERHEAD);
615 #else
616 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
617 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
618 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
619 #endif
622 free (val);
625 #undef malloc
626 #undef realloc
627 #undef free
628 #define malloc overrun_check_malloc
629 #define realloc overrun_check_realloc
630 #define free overrun_check_free
631 #endif
633 /* If compiled with XMALLOC_BLOCK_INPUT_CHECK, define a symbol
634 BLOCK_INPUT_IN_MEMORY_ALLOCATORS that is visible to the debugger.
635 If that variable is set, block input while in one of Emacs's memory
636 allocation functions. There should be no need for this debugging
637 option, since signal handlers do not allocate memory, but Emacs
638 formerly allocated memory in signal handlers and this compile-time
639 option remains as a way to help debug the issue should it rear its
640 ugly head again. */
641 #ifdef XMALLOC_BLOCK_INPUT_CHECK
642 bool block_input_in_memory_allocators EXTERNALLY_VISIBLE;
643 static void
644 malloc_block_input (void)
646 if (block_input_in_memory_allocators)
647 block_input ();
649 static void
650 malloc_unblock_input (void)
652 if (block_input_in_memory_allocators)
653 unblock_input ();
655 # define MALLOC_BLOCK_INPUT malloc_block_input ()
656 # define MALLOC_UNBLOCK_INPUT malloc_unblock_input ()
657 #else
658 # define MALLOC_BLOCK_INPUT ((void) 0)
659 # define MALLOC_UNBLOCK_INPUT ((void) 0)
660 #endif
662 #define MALLOC_PROBE(size) \
663 do { \
664 if (profiler_memory_running) \
665 malloc_probe (size); \
666 } while (0)
669 /* Like malloc but check for no memory and block interrupt input.. */
671 void *
672 xmalloc (size_t size)
674 void *val;
676 MALLOC_BLOCK_INPUT;
677 val = malloc (size);
678 MALLOC_UNBLOCK_INPUT;
680 if (!val && size)
681 memory_full (size);
682 MALLOC_PROBE (size);
683 return val;
686 /* Like the above, but zeroes out the memory just allocated. */
688 void *
689 xzalloc (size_t size)
691 void *val;
693 MALLOC_BLOCK_INPUT;
694 val = malloc (size);
695 MALLOC_UNBLOCK_INPUT;
697 if (!val && size)
698 memory_full (size);
699 memset (val, 0, size);
700 MALLOC_PROBE (size);
701 return val;
704 /* Like realloc but check for no memory and block interrupt input.. */
706 void *
707 xrealloc (void *block, size_t size)
709 void *val;
711 MALLOC_BLOCK_INPUT;
712 /* We must call malloc explicitly when BLOCK is 0, since some
713 reallocs don't do this. */
714 if (! block)
715 val = malloc (size);
716 else
717 val = realloc (block, size);
718 MALLOC_UNBLOCK_INPUT;
720 if (!val && size)
721 memory_full (size);
722 MALLOC_PROBE (size);
723 return val;
727 /* Like free but block interrupt input. */
729 void
730 xfree (void *block)
732 if (!block)
733 return;
734 MALLOC_BLOCK_INPUT;
735 free (block);
736 MALLOC_UNBLOCK_INPUT;
737 /* We don't call refill_memory_reserve here
738 because in practice the call in r_alloc_free seems to suffice. */
742 /* Other parts of Emacs pass large int values to allocator functions
743 expecting ptrdiff_t. This is portable in practice, but check it to
744 be safe. */
745 verify (INT_MAX <= PTRDIFF_MAX);
748 /* Allocate an array of NITEMS items, each of size ITEM_SIZE.
749 Signal an error on memory exhaustion, and block interrupt input. */
751 void *
752 xnmalloc (ptrdiff_t nitems, ptrdiff_t item_size)
754 eassert (0 <= nitems && 0 < item_size);
755 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
756 memory_full (SIZE_MAX);
757 return xmalloc (nitems * item_size);
761 /* Reallocate an array PA to make it of NITEMS items, each of size ITEM_SIZE.
762 Signal an error on memory exhaustion, and block interrupt input. */
764 void *
765 xnrealloc (void *pa, ptrdiff_t nitems, ptrdiff_t item_size)
767 eassert (0 <= nitems && 0 < item_size);
768 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
769 memory_full (SIZE_MAX);
770 return xrealloc (pa, nitems * item_size);
774 /* Grow PA, which points to an array of *NITEMS items, and return the
775 location of the reallocated array, updating *NITEMS to reflect its
776 new size. The new array will contain at least NITEMS_INCR_MIN more
777 items, but will not contain more than NITEMS_MAX items total.
778 ITEM_SIZE is the size of each item, in bytes.
780 ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be
781 nonnegative. If NITEMS_MAX is -1, it is treated as if it were
782 infinity.
784 If PA is null, then allocate a new array instead of reallocating
785 the old one.
787 Block interrupt input as needed. If memory exhaustion occurs, set
788 *NITEMS to zero if PA is null, and signal an error (i.e., do not
789 return).
791 Thus, to grow an array A without saving its old contents, do
792 { xfree (A); A = NULL; A = xpalloc (NULL, &AITEMS, ...); }.
793 The A = NULL avoids a dangling pointer if xpalloc exhausts memory
794 and signals an error, and later this code is reexecuted and
795 attempts to free A. */
797 void *
798 xpalloc (void *pa, ptrdiff_t *nitems, ptrdiff_t nitems_incr_min,
799 ptrdiff_t nitems_max, ptrdiff_t item_size)
801 /* The approximate size to use for initial small allocation
802 requests. This is the largest "small" request for the GNU C
803 library malloc. */
804 enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
806 /* If the array is tiny, grow it to about (but no greater than)
807 DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%. */
808 ptrdiff_t n = *nitems;
809 ptrdiff_t tiny_max = DEFAULT_MXFAST / item_size - n;
810 ptrdiff_t half_again = n >> 1;
811 ptrdiff_t incr_estimate = max (tiny_max, half_again);
813 /* Adjust the increment according to three constraints: NITEMS_INCR_MIN,
814 NITEMS_MAX, and what the C language can represent safely. */
815 ptrdiff_t C_language_max = min (PTRDIFF_MAX, SIZE_MAX) / item_size;
816 ptrdiff_t n_max = (0 <= nitems_max && nitems_max < C_language_max
817 ? nitems_max : C_language_max);
818 ptrdiff_t nitems_incr_max = n_max - n;
819 ptrdiff_t incr = max (nitems_incr_min, min (incr_estimate, nitems_incr_max));
821 eassert (0 < item_size && 0 < nitems_incr_min && 0 <= n && -1 <= nitems_max);
822 if (! pa)
823 *nitems = 0;
824 if (nitems_incr_max < incr)
825 memory_full (SIZE_MAX);
826 n += incr;
827 pa = xrealloc (pa, n * item_size);
828 *nitems = n;
829 return pa;
833 /* Like strdup, but uses xmalloc. */
835 char *
836 xstrdup (const char *s)
838 ptrdiff_t size;
839 eassert (s);
840 size = strlen (s) + 1;
841 return memcpy (xmalloc (size), s, size);
844 /* Like above, but duplicates Lisp string to C string. */
846 char *
847 xlispstrdup (Lisp_Object string)
849 ptrdiff_t size = SBYTES (string) + 1;
850 return memcpy (xmalloc (size), SSDATA (string), size);
853 /* Assign to *PTR a copy of STRING, freeing any storage *PTR formerly
854 pointed to. If STRING is null, assign it without copying anything.
855 Allocate before freeing, to avoid a dangling pointer if allocation
856 fails. */
858 void
859 dupstring (char **ptr, char const *string)
861 char *old = *ptr;
862 *ptr = string ? xstrdup (string) : 0;
863 xfree (old);
867 /* Like putenv, but (1) use the equivalent of xmalloc and (2) the
868 argument is a const pointer. */
870 void
871 xputenv (char const *string)
873 if (putenv ((char *) string) != 0)
874 memory_full (0);
877 /* Return a newly allocated memory block of SIZE bytes, remembering
878 to free it when unwinding. */
879 void *
880 record_xmalloc (size_t size)
882 void *p = xmalloc (size);
883 record_unwind_protect_ptr (xfree, p);
884 return p;
888 /* Like malloc but used for allocating Lisp data. NBYTES is the
889 number of bytes to allocate, TYPE describes the intended use of the
890 allocated memory block (for strings, for conses, ...). */
892 #if ! USE_LSB_TAG
893 void *lisp_malloc_loser EXTERNALLY_VISIBLE;
894 #endif
896 static void *
897 lisp_malloc (size_t nbytes, enum mem_type type)
899 register void *val;
901 MALLOC_BLOCK_INPUT;
903 #ifdef GC_MALLOC_CHECK
904 allocated_mem_type = type;
905 #endif
907 val = malloc (nbytes);
909 #if ! USE_LSB_TAG
910 /* If the memory just allocated cannot be addressed thru a Lisp
911 object's pointer, and it needs to be,
912 that's equivalent to running out of memory. */
913 if (val && type != MEM_TYPE_NON_LISP)
915 Lisp_Object tem;
916 XSETCONS (tem, (char *) val + nbytes - 1);
917 if ((char *) XCONS (tem) != (char *) val + nbytes - 1)
919 lisp_malloc_loser = val;
920 free (val);
921 val = 0;
924 #endif
926 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
927 if (val && type != MEM_TYPE_NON_LISP)
928 mem_insert (val, (char *) val + nbytes, type);
929 #endif
931 MALLOC_UNBLOCK_INPUT;
932 if (!val && nbytes)
933 memory_full (nbytes);
934 MALLOC_PROBE (nbytes);
935 return val;
938 /* Free BLOCK. This must be called to free memory allocated with a
939 call to lisp_malloc. */
941 static void
942 lisp_free (void *block)
944 MALLOC_BLOCK_INPUT;
945 free (block);
946 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
947 mem_delete (mem_find (block));
948 #endif
949 MALLOC_UNBLOCK_INPUT;
952 /***** Allocation of aligned blocks of memory to store Lisp data. *****/
954 /* The entry point is lisp_align_malloc which returns blocks of at most
955 BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary. */
957 /* Use aligned_alloc if it or a simple substitute is available.
958 Address sanitization breaks aligned allocation, as of gcc 4.8.2 and
959 clang 3.3 anyway. */
961 #if ! ADDRESS_SANITIZER
962 # if !defined SYSTEM_MALLOC && !defined DOUG_LEA_MALLOC
963 # define USE_ALIGNED_ALLOC 1
964 /* Defined in gmalloc.c. */
965 void *aligned_alloc (size_t, size_t);
966 # elif defined HAVE_ALIGNED_ALLOC
967 # define USE_ALIGNED_ALLOC 1
968 # elif defined HAVE_POSIX_MEMALIGN
969 # define USE_ALIGNED_ALLOC 1
970 static void *
971 aligned_alloc (size_t alignment, size_t size)
973 void *p;
974 return posix_memalign (&p, alignment, size) == 0 ? p : 0;
976 # endif
977 #endif
979 /* BLOCK_ALIGN has to be a power of 2. */
980 #define BLOCK_ALIGN (1 << 10)
982 /* Padding to leave at the end of a malloc'd block. This is to give
983 malloc a chance to minimize the amount of memory wasted to alignment.
984 It should be tuned to the particular malloc library used.
985 On glibc-2.3.2, malloc never tries to align, so a padding of 0 is best.
986 aligned_alloc on the other hand would ideally prefer a value of 4
987 because otherwise, there's 1020 bytes wasted between each ablocks.
988 In Emacs, testing shows that those 1020 can most of the time be
989 efficiently used by malloc to place other objects, so a value of 0 can
990 still preferable unless you have a lot of aligned blocks and virtually
991 nothing else. */
992 #define BLOCK_PADDING 0
993 #define BLOCK_BYTES \
994 (BLOCK_ALIGN - sizeof (struct ablocks *) - BLOCK_PADDING)
996 /* Internal data structures and constants. */
998 #define ABLOCKS_SIZE 16
1000 /* An aligned block of memory. */
1001 struct ablock
1003 union
1005 char payload[BLOCK_BYTES];
1006 struct ablock *next_free;
1007 } x;
1008 /* `abase' is the aligned base of the ablocks. */
1009 /* It is overloaded to hold the virtual `busy' field that counts
1010 the number of used ablock in the parent ablocks.
1011 The first ablock has the `busy' field, the others have the `abase'
1012 field. To tell the difference, we assume that pointers will have
1013 integer values larger than 2 * ABLOCKS_SIZE. The lowest bit of `busy'
1014 is used to tell whether the real base of the parent ablocks is `abase'
1015 (if not, the word before the first ablock holds a pointer to the
1016 real base). */
1017 struct ablocks *abase;
1018 /* The padding of all but the last ablock is unused. The padding of
1019 the last ablock in an ablocks is not allocated. */
1020 #if BLOCK_PADDING
1021 char padding[BLOCK_PADDING];
1022 #endif
1025 /* A bunch of consecutive aligned blocks. */
1026 struct ablocks
1028 struct ablock blocks[ABLOCKS_SIZE];
1031 /* Size of the block requested from malloc or aligned_alloc. */
1032 #define ABLOCKS_BYTES (sizeof (struct ablocks) - BLOCK_PADDING)
1034 #define ABLOCK_ABASE(block) \
1035 (((uintptr_t) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE) \
1036 ? (struct ablocks *)(block) \
1037 : (block)->abase)
1039 /* Virtual `busy' field. */
1040 #define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
1042 /* Pointer to the (not necessarily aligned) malloc block. */
1043 #ifdef USE_ALIGNED_ALLOC
1044 #define ABLOCKS_BASE(abase) (abase)
1045 #else
1046 #define ABLOCKS_BASE(abase) \
1047 (1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void **)abase)[-1])
1048 #endif
1050 /* The list of free ablock. */
1051 static struct ablock *free_ablock;
1053 /* Allocate an aligned block of nbytes.
1054 Alignment is on a multiple of BLOCK_ALIGN and `nbytes' has to be
1055 smaller or equal to BLOCK_BYTES. */
1056 static void *
1057 lisp_align_malloc (size_t nbytes, enum mem_type type)
1059 void *base, *val;
1060 struct ablocks *abase;
1062 eassert (nbytes <= BLOCK_BYTES);
1064 MALLOC_BLOCK_INPUT;
1066 #ifdef GC_MALLOC_CHECK
1067 allocated_mem_type = type;
1068 #endif
1070 if (!free_ablock)
1072 int i;
1073 intptr_t aligned; /* int gets warning casting to 64-bit pointer. */
1075 #ifdef DOUG_LEA_MALLOC
1076 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1077 because mapped region contents are not preserved in
1078 a dumped Emacs. */
1079 mallopt (M_MMAP_MAX, 0);
1080 #endif
1082 #ifdef USE_ALIGNED_ALLOC
1083 abase = base = aligned_alloc (BLOCK_ALIGN, ABLOCKS_BYTES);
1084 #else
1085 base = malloc (ABLOCKS_BYTES);
1086 abase = ALIGN (base, BLOCK_ALIGN);
1087 #endif
1089 if (base == 0)
1091 MALLOC_UNBLOCK_INPUT;
1092 memory_full (ABLOCKS_BYTES);
1095 aligned = (base == abase);
1096 if (!aligned)
1097 ((void **) abase)[-1] = base;
1099 #ifdef DOUG_LEA_MALLOC
1100 /* Back to a reasonable maximum of mmap'ed areas. */
1101 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
1102 #endif
1104 #if ! USE_LSB_TAG
1105 /* If the memory just allocated cannot be addressed thru a Lisp
1106 object's pointer, and it needs to be, that's equivalent to
1107 running out of memory. */
1108 if (type != MEM_TYPE_NON_LISP)
1110 Lisp_Object tem;
1111 char *end = (char *) base + ABLOCKS_BYTES - 1;
1112 XSETCONS (tem, end);
1113 if ((char *) XCONS (tem) != end)
1115 lisp_malloc_loser = base;
1116 free (base);
1117 MALLOC_UNBLOCK_INPUT;
1118 memory_full (SIZE_MAX);
1121 #endif
1123 /* Initialize the blocks and put them on the free list.
1124 If `base' was not properly aligned, we can't use the last block. */
1125 for (i = 0; i < (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1); i++)
1127 abase->blocks[i].abase = abase;
1128 abase->blocks[i].x.next_free = free_ablock;
1129 free_ablock = &abase->blocks[i];
1131 ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
1133 eassert (0 == ((uintptr_t) abase) % BLOCK_ALIGN);
1134 eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
1135 eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
1136 eassert (ABLOCKS_BASE (abase) == base);
1137 eassert (aligned == (intptr_t) ABLOCKS_BUSY (abase));
1140 abase = ABLOCK_ABASE (free_ablock);
1141 ABLOCKS_BUSY (abase)
1142 = (struct ablocks *) (2 + (intptr_t) ABLOCKS_BUSY (abase));
1143 val = free_ablock;
1144 free_ablock = free_ablock->x.next_free;
1146 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1147 if (type != MEM_TYPE_NON_LISP)
1148 mem_insert (val, (char *) val + nbytes, type);
1149 #endif
1151 MALLOC_UNBLOCK_INPUT;
1153 MALLOC_PROBE (nbytes);
1155 eassert (0 == ((uintptr_t) val) % BLOCK_ALIGN);
1156 return val;
1159 static void
1160 lisp_align_free (void *block)
1162 struct ablock *ablock = block;
1163 struct ablocks *abase = ABLOCK_ABASE (ablock);
1165 MALLOC_BLOCK_INPUT;
1166 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1167 mem_delete (mem_find (block));
1168 #endif
1169 /* Put on free list. */
1170 ablock->x.next_free = free_ablock;
1171 free_ablock = ablock;
1172 /* Update busy count. */
1173 ABLOCKS_BUSY (abase)
1174 = (struct ablocks *) (-2 + (intptr_t) ABLOCKS_BUSY (abase));
1176 if (2 > (intptr_t) ABLOCKS_BUSY (abase))
1177 { /* All the blocks are free. */
1178 int i = 0, aligned = (intptr_t) ABLOCKS_BUSY (abase);
1179 struct ablock **tem = &free_ablock;
1180 struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
1182 while (*tem)
1184 if (*tem >= (struct ablock *) abase && *tem < atop)
1186 i++;
1187 *tem = (*tem)->x.next_free;
1189 else
1190 tem = &(*tem)->x.next_free;
1192 eassert ((aligned & 1) == aligned);
1193 eassert (i == (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1));
1194 #ifdef USE_POSIX_MEMALIGN
1195 eassert ((uintptr_t) ABLOCKS_BASE (abase) % BLOCK_ALIGN == 0);
1196 #endif
1197 free (ABLOCKS_BASE (abase));
1199 MALLOC_UNBLOCK_INPUT;
1203 /***********************************************************************
1204 Interval Allocation
1205 ***********************************************************************/
1207 /* Number of intervals allocated in an interval_block structure.
1208 The 1020 is 1024 minus malloc overhead. */
1210 #define INTERVAL_BLOCK_SIZE \
1211 ((1020 - sizeof (struct interval_block *)) / sizeof (struct interval))
1213 /* Intervals are allocated in chunks in the form of an interval_block
1214 structure. */
1216 struct interval_block
1218 /* Place `intervals' first, to preserve alignment. */
1219 struct interval intervals[INTERVAL_BLOCK_SIZE];
1220 struct interval_block *next;
1223 /* Current interval block. Its `next' pointer points to older
1224 blocks. */
1226 static struct interval_block *interval_block;
1228 /* Index in interval_block above of the next unused interval
1229 structure. */
1231 static int interval_block_index = INTERVAL_BLOCK_SIZE;
1233 /* Number of free and live intervals. */
1235 static EMACS_INT total_free_intervals, total_intervals;
1237 /* List of free intervals. */
1239 static INTERVAL interval_free_list;
1241 /* Return a new interval. */
1243 INTERVAL
1244 make_interval (void)
1246 INTERVAL val;
1248 MALLOC_BLOCK_INPUT;
1250 if (interval_free_list)
1252 val = interval_free_list;
1253 interval_free_list = INTERVAL_PARENT (interval_free_list);
1255 else
1257 if (interval_block_index == INTERVAL_BLOCK_SIZE)
1259 struct interval_block *newi
1260 = lisp_malloc (sizeof *newi, MEM_TYPE_NON_LISP);
1262 newi->next = interval_block;
1263 interval_block = newi;
1264 interval_block_index = 0;
1265 total_free_intervals += INTERVAL_BLOCK_SIZE;
1267 val = &interval_block->intervals[interval_block_index++];
1270 MALLOC_UNBLOCK_INPUT;
1272 consing_since_gc += sizeof (struct interval);
1273 intervals_consed++;
1274 total_free_intervals--;
1275 RESET_INTERVAL (val);
1276 val->gcmarkbit = 0;
1277 return val;
1281 /* Mark Lisp objects in interval I. */
1283 static void
1284 mark_interval (register INTERVAL i, Lisp_Object dummy)
1286 /* Intervals should never be shared. So, if extra internal checking is
1287 enabled, GC aborts if it seems to have visited an interval twice. */
1288 eassert (!i->gcmarkbit);
1289 i->gcmarkbit = 1;
1290 mark_object (i->plist);
1293 /* Mark the interval tree rooted in I. */
1295 #define MARK_INTERVAL_TREE(i) \
1296 do { \
1297 if (i && !i->gcmarkbit) \
1298 traverse_intervals_noorder (i, mark_interval, Qnil); \
1299 } while (0)
1301 /***********************************************************************
1302 String Allocation
1303 ***********************************************************************/
1305 /* Lisp_Strings are allocated in string_block structures. When a new
1306 string_block is allocated, all the Lisp_Strings it contains are
1307 added to a free-list string_free_list. When a new Lisp_String is
1308 needed, it is taken from that list. During the sweep phase of GC,
1309 string_blocks that are entirely free are freed, except two which
1310 we keep.
1312 String data is allocated from sblock structures. Strings larger
1313 than LARGE_STRING_BYTES, get their own sblock, data for smaller
1314 strings is sub-allocated out of sblocks of size SBLOCK_SIZE.
1316 Sblocks consist internally of sdata structures, one for each
1317 Lisp_String. The sdata structure points to the Lisp_String it
1318 belongs to. The Lisp_String points back to the `u.data' member of
1319 its sdata structure.
1321 When a Lisp_String is freed during GC, it is put back on
1322 string_free_list, and its `data' member and its sdata's `string'
1323 pointer is set to null. The size of the string is recorded in the
1324 `n.nbytes' member of the sdata. So, sdata structures that are no
1325 longer used, can be easily recognized, and it's easy to compact the
1326 sblocks of small strings which we do in compact_small_strings. */
1328 /* Size in bytes of an sblock structure used for small strings. This
1329 is 8192 minus malloc overhead. */
1331 #define SBLOCK_SIZE 8188
1333 /* Strings larger than this are considered large strings. String data
1334 for large strings is allocated from individual sblocks. */
1336 #define LARGE_STRING_BYTES 1024
1338 /* The SDATA typedef is a struct or union describing string memory
1339 sub-allocated from an sblock. This is where the contents of Lisp
1340 strings are stored. */
1342 struct sdata
1344 /* Back-pointer to the string this sdata belongs to. If null, this
1345 structure is free, and NBYTES (in this structure or in the union below)
1346 contains the string's byte size (the same value that STRING_BYTES
1347 would return if STRING were non-null). If non-null, STRING_BYTES
1348 (STRING) is the size of the data, and DATA contains the string's
1349 contents. */
1350 struct Lisp_String *string;
1352 #ifdef GC_CHECK_STRING_BYTES
1353 ptrdiff_t nbytes;
1354 #endif
1356 unsigned char data[FLEXIBLE_ARRAY_MEMBER];
1359 #ifdef GC_CHECK_STRING_BYTES
1361 typedef struct sdata sdata;
1362 #define SDATA_NBYTES(S) (S)->nbytes
1363 #define SDATA_DATA(S) (S)->data
1365 #else
1367 typedef union
1369 struct Lisp_String *string;
1371 /* When STRING is nonnull, this union is actually of type 'struct sdata',
1372 which has a flexible array member. However, if implemented by
1373 giving this union a member of type 'struct sdata', the union
1374 could not be the last (flexible) member of 'struct sblock',
1375 because C99 prohibits a flexible array member from having a type
1376 that is itself a flexible array. So, comment this member out here,
1377 but remember that the option's there when using this union. */
1378 #if 0
1379 struct sdata u;
1380 #endif
1382 /* When STRING is null. */
1383 struct
1385 struct Lisp_String *string;
1386 ptrdiff_t nbytes;
1387 } n;
1388 } sdata;
1390 #define SDATA_NBYTES(S) (S)->n.nbytes
1391 #define SDATA_DATA(S) ((struct sdata *) (S))->data
1393 #endif /* not GC_CHECK_STRING_BYTES */
1395 enum { SDATA_DATA_OFFSET = offsetof (struct sdata, data) };
1397 /* Structure describing a block of memory which is sub-allocated to
1398 obtain string data memory for strings. Blocks for small strings
1399 are of fixed size SBLOCK_SIZE. Blocks for large strings are made
1400 as large as needed. */
1402 struct sblock
1404 /* Next in list. */
1405 struct sblock *next;
1407 /* Pointer to the next free sdata block. This points past the end
1408 of the sblock if there isn't any space left in this block. */
1409 sdata *next_free;
1411 /* String data. */
1412 sdata data[FLEXIBLE_ARRAY_MEMBER];
1415 /* Number of Lisp strings in a string_block structure. The 1020 is
1416 1024 minus malloc overhead. */
1418 #define STRING_BLOCK_SIZE \
1419 ((1020 - sizeof (struct string_block *)) / sizeof (struct Lisp_String))
1421 /* Structure describing a block from which Lisp_String structures
1422 are allocated. */
1424 struct string_block
1426 /* Place `strings' first, to preserve alignment. */
1427 struct Lisp_String strings[STRING_BLOCK_SIZE];
1428 struct string_block *next;
1431 /* Head and tail of the list of sblock structures holding Lisp string
1432 data. We always allocate from current_sblock. The NEXT pointers
1433 in the sblock structures go from oldest_sblock to current_sblock. */
1435 static struct sblock *oldest_sblock, *current_sblock;
1437 /* List of sblocks for large strings. */
1439 static struct sblock *large_sblocks;
1441 /* List of string_block structures. */
1443 static struct string_block *string_blocks;
1445 /* Free-list of Lisp_Strings. */
1447 static struct Lisp_String *string_free_list;
1449 /* Number of live and free Lisp_Strings. */
1451 static EMACS_INT total_strings, total_free_strings;
1453 /* Number of bytes used by live strings. */
1455 static EMACS_INT total_string_bytes;
1457 /* Given a pointer to a Lisp_String S which is on the free-list
1458 string_free_list, return a pointer to its successor in the
1459 free-list. */
1461 #define NEXT_FREE_LISP_STRING(S) (*(struct Lisp_String **) (S))
1463 /* Return a pointer to the sdata structure belonging to Lisp string S.
1464 S must be live, i.e. S->data must not be null. S->data is actually
1465 a pointer to the `u.data' member of its sdata structure; the
1466 structure starts at a constant offset in front of that. */
1468 #define SDATA_OF_STRING(S) ((sdata *) ((S)->data - SDATA_DATA_OFFSET))
1471 #ifdef GC_CHECK_STRING_OVERRUN
1473 /* We check for overrun in string data blocks by appending a small
1474 "cookie" after each allocated string data block, and check for the
1475 presence of this cookie during GC. */
1477 #define GC_STRING_OVERRUN_COOKIE_SIZE 4
1478 static char const string_overrun_cookie[GC_STRING_OVERRUN_COOKIE_SIZE] =
1479 { '\xde', '\xad', '\xbe', '\xef' };
1481 #else
1482 #define GC_STRING_OVERRUN_COOKIE_SIZE 0
1483 #endif
1485 /* Value is the size of an sdata structure large enough to hold NBYTES
1486 bytes of string data. The value returned includes a terminating
1487 NUL byte, the size of the sdata structure, and padding. */
1489 #ifdef GC_CHECK_STRING_BYTES
1491 #define SDATA_SIZE(NBYTES) \
1492 ((SDATA_DATA_OFFSET \
1493 + (NBYTES) + 1 \
1494 + sizeof (ptrdiff_t) - 1) \
1495 & ~(sizeof (ptrdiff_t) - 1))
1497 #else /* not GC_CHECK_STRING_BYTES */
1499 /* The 'max' reserves space for the nbytes union member even when NBYTES + 1 is
1500 less than the size of that member. The 'max' is not needed when
1501 SDATA_DATA_OFFSET is a multiple of sizeof (ptrdiff_t), because then the
1502 alignment code reserves enough space. */
1504 #define SDATA_SIZE(NBYTES) \
1505 ((SDATA_DATA_OFFSET \
1506 + (SDATA_DATA_OFFSET % sizeof (ptrdiff_t) == 0 \
1507 ? NBYTES \
1508 : max (NBYTES, sizeof (ptrdiff_t) - 1)) \
1509 + 1 \
1510 + sizeof (ptrdiff_t) - 1) \
1511 & ~(sizeof (ptrdiff_t) - 1))
1513 #endif /* not GC_CHECK_STRING_BYTES */
1515 /* Extra bytes to allocate for each string. */
1517 #define GC_STRING_EXTRA (GC_STRING_OVERRUN_COOKIE_SIZE)
1519 /* Exact bound on the number of bytes in a string, not counting the
1520 terminating null. A string cannot contain more bytes than
1521 STRING_BYTES_BOUND, nor can it be so long that the size_t
1522 arithmetic in allocate_string_data would overflow while it is
1523 calculating a value to be passed to malloc. */
1524 static ptrdiff_t const STRING_BYTES_MAX =
1525 min (STRING_BYTES_BOUND,
1526 ((SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD
1527 - GC_STRING_EXTRA
1528 - offsetof (struct sblock, data)
1529 - SDATA_DATA_OFFSET)
1530 & ~(sizeof (EMACS_INT) - 1)));
1532 /* Initialize string allocation. Called from init_alloc_once. */
1534 static void
1535 init_strings (void)
1537 empty_unibyte_string = make_pure_string ("", 0, 0, 0);
1538 empty_multibyte_string = make_pure_string ("", 0, 0, 1);
1542 #ifdef GC_CHECK_STRING_BYTES
1544 static int check_string_bytes_count;
1546 /* Like STRING_BYTES, but with debugging check. Can be
1547 called during GC, so pay attention to the mark bit. */
1549 ptrdiff_t
1550 string_bytes (struct Lisp_String *s)
1552 ptrdiff_t nbytes =
1553 (s->size_byte < 0 ? s->size & ~ARRAY_MARK_FLAG : s->size_byte);
1555 if (!PURE_POINTER_P (s)
1556 && s->data
1557 && nbytes != SDATA_NBYTES (SDATA_OF_STRING (s)))
1558 emacs_abort ();
1559 return nbytes;
1562 /* Check validity of Lisp strings' string_bytes member in B. */
1564 static void
1565 check_sblock (struct sblock *b)
1567 sdata *from, *end, *from_end;
1569 end = b->next_free;
1571 for (from = b->data; from < end; from = from_end)
1573 /* Compute the next FROM here because copying below may
1574 overwrite data we need to compute it. */
1575 ptrdiff_t nbytes;
1577 /* Check that the string size recorded in the string is the
1578 same as the one recorded in the sdata structure. */
1579 nbytes = SDATA_SIZE (from->string ? string_bytes (from->string)
1580 : SDATA_NBYTES (from));
1581 from_end = (sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
1586 /* Check validity of Lisp strings' string_bytes member. ALL_P
1587 means check all strings, otherwise check only most
1588 recently allocated strings. Used for hunting a bug. */
1590 static void
1591 check_string_bytes (bool all_p)
1593 if (all_p)
1595 struct sblock *b;
1597 for (b = large_sblocks; b; b = b->next)
1599 struct Lisp_String *s = b->data[0].string;
1600 if (s)
1601 string_bytes (s);
1604 for (b = oldest_sblock; b; b = b->next)
1605 check_sblock (b);
1607 else if (current_sblock)
1608 check_sblock (current_sblock);
1611 #else /* not GC_CHECK_STRING_BYTES */
1613 #define check_string_bytes(all) ((void) 0)
1615 #endif /* GC_CHECK_STRING_BYTES */
1617 #ifdef GC_CHECK_STRING_FREE_LIST
1619 /* Walk through the string free list looking for bogus next pointers.
1620 This may catch buffer overrun from a previous string. */
1622 static void
1623 check_string_free_list (void)
1625 struct Lisp_String *s;
1627 /* Pop a Lisp_String off the free-list. */
1628 s = string_free_list;
1629 while (s != NULL)
1631 if ((uintptr_t) s < 1024)
1632 emacs_abort ();
1633 s = NEXT_FREE_LISP_STRING (s);
1636 #else
1637 #define check_string_free_list()
1638 #endif
1640 /* Return a new Lisp_String. */
1642 static struct Lisp_String *
1643 allocate_string (void)
1645 struct Lisp_String *s;
1647 MALLOC_BLOCK_INPUT;
1649 /* If the free-list is empty, allocate a new string_block, and
1650 add all the Lisp_Strings in it to the free-list. */
1651 if (string_free_list == NULL)
1653 struct string_block *b = lisp_malloc (sizeof *b, MEM_TYPE_STRING);
1654 int i;
1656 b->next = string_blocks;
1657 string_blocks = b;
1659 for (i = STRING_BLOCK_SIZE - 1; i >= 0; --i)
1661 s = b->strings + i;
1662 /* Every string on a free list should have NULL data pointer. */
1663 s->data = NULL;
1664 NEXT_FREE_LISP_STRING (s) = string_free_list;
1665 string_free_list = s;
1668 total_free_strings += STRING_BLOCK_SIZE;
1671 check_string_free_list ();
1673 /* Pop a Lisp_String off the free-list. */
1674 s = string_free_list;
1675 string_free_list = NEXT_FREE_LISP_STRING (s);
1677 MALLOC_UNBLOCK_INPUT;
1679 --total_free_strings;
1680 ++total_strings;
1681 ++strings_consed;
1682 consing_since_gc += sizeof *s;
1684 #ifdef GC_CHECK_STRING_BYTES
1685 if (!noninteractive)
1687 if (++check_string_bytes_count == 200)
1689 check_string_bytes_count = 0;
1690 check_string_bytes (1);
1692 else
1693 check_string_bytes (0);
1695 #endif /* GC_CHECK_STRING_BYTES */
1697 return s;
1701 /* Set up Lisp_String S for holding NCHARS characters, NBYTES bytes,
1702 plus a NUL byte at the end. Allocate an sdata structure for S, and
1703 set S->data to its `u.data' member. Store a NUL byte at the end of
1704 S->data. Set S->size to NCHARS and S->size_byte to NBYTES. Free
1705 S->data if it was initially non-null. */
1707 void
1708 allocate_string_data (struct Lisp_String *s,
1709 EMACS_INT nchars, EMACS_INT nbytes)
1711 sdata *data, *old_data;
1712 struct sblock *b;
1713 ptrdiff_t needed, old_nbytes;
1715 if (STRING_BYTES_MAX < nbytes)
1716 string_overflow ();
1718 /* Determine the number of bytes needed to store NBYTES bytes
1719 of string data. */
1720 needed = SDATA_SIZE (nbytes);
1721 if (s->data)
1723 old_data = SDATA_OF_STRING (s);
1724 old_nbytes = STRING_BYTES (s);
1726 else
1727 old_data = NULL;
1729 MALLOC_BLOCK_INPUT;
1731 if (nbytes > LARGE_STRING_BYTES)
1733 size_t size = offsetof (struct sblock, data) + needed;
1735 #ifdef DOUG_LEA_MALLOC
1736 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1737 because mapped region contents are not preserved in
1738 a dumped Emacs.
1740 In case you think of allowing it in a dumped Emacs at the
1741 cost of not being able to re-dump, there's another reason:
1742 mmap'ed data typically have an address towards the top of the
1743 address space, which won't fit into an EMACS_INT (at least on
1744 32-bit systems with the current tagging scheme). --fx */
1745 mallopt (M_MMAP_MAX, 0);
1746 #endif
1748 b = lisp_malloc (size + GC_STRING_EXTRA, MEM_TYPE_NON_LISP);
1750 #ifdef DOUG_LEA_MALLOC
1751 /* Back to a reasonable maximum of mmap'ed areas. */
1752 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
1753 #endif
1755 b->next_free = b->data;
1756 b->data[0].string = NULL;
1757 b->next = large_sblocks;
1758 large_sblocks = b;
1760 else if (current_sblock == NULL
1761 || (((char *) current_sblock + SBLOCK_SIZE
1762 - (char *) current_sblock->next_free)
1763 < (needed + GC_STRING_EXTRA)))
1765 /* Not enough room in the current sblock. */
1766 b = lisp_malloc (SBLOCK_SIZE, MEM_TYPE_NON_LISP);
1767 b->next_free = b->data;
1768 b->data[0].string = NULL;
1769 b->next = NULL;
1771 if (current_sblock)
1772 current_sblock->next = b;
1773 else
1774 oldest_sblock = b;
1775 current_sblock = b;
1777 else
1778 b = current_sblock;
1780 data = b->next_free;
1781 b->next_free = (sdata *) ((char *) data + needed + GC_STRING_EXTRA);
1783 MALLOC_UNBLOCK_INPUT;
1785 data->string = s;
1786 s->data = SDATA_DATA (data);
1787 #ifdef GC_CHECK_STRING_BYTES
1788 SDATA_NBYTES (data) = nbytes;
1789 #endif
1790 s->size = nchars;
1791 s->size_byte = nbytes;
1792 s->data[nbytes] = '\0';
1793 #ifdef GC_CHECK_STRING_OVERRUN
1794 memcpy ((char *) data + needed, string_overrun_cookie,
1795 GC_STRING_OVERRUN_COOKIE_SIZE);
1796 #endif
1798 /* Note that Faset may call to this function when S has already data
1799 assigned. In this case, mark data as free by setting it's string
1800 back-pointer to null, and record the size of the data in it. */
1801 if (old_data)
1803 SDATA_NBYTES (old_data) = old_nbytes;
1804 old_data->string = NULL;
1807 consing_since_gc += needed;
1811 /* Sweep and compact strings. */
1813 static void
1814 sweep_strings (void)
1816 struct string_block *b, *next;
1817 struct string_block *live_blocks = NULL;
1819 string_free_list = NULL;
1820 total_strings = total_free_strings = 0;
1821 total_string_bytes = 0;
1823 /* Scan strings_blocks, free Lisp_Strings that aren't marked. */
1824 for (b = string_blocks; b; b = next)
1826 int i, nfree = 0;
1827 struct Lisp_String *free_list_before = string_free_list;
1829 next = b->next;
1831 for (i = 0; i < STRING_BLOCK_SIZE; ++i)
1833 struct Lisp_String *s = b->strings + i;
1835 if (s->data)
1837 /* String was not on free-list before. */
1838 if (STRING_MARKED_P (s))
1840 /* String is live; unmark it and its intervals. */
1841 UNMARK_STRING (s);
1843 /* Do not use string_(set|get)_intervals here. */
1844 s->intervals = balance_intervals (s->intervals);
1846 ++total_strings;
1847 total_string_bytes += STRING_BYTES (s);
1849 else
1851 /* String is dead. Put it on the free-list. */
1852 sdata *data = SDATA_OF_STRING (s);
1854 /* Save the size of S in its sdata so that we know
1855 how large that is. Reset the sdata's string
1856 back-pointer so that we know it's free. */
1857 #ifdef GC_CHECK_STRING_BYTES
1858 if (string_bytes (s) != SDATA_NBYTES (data))
1859 emacs_abort ();
1860 #else
1861 data->n.nbytes = STRING_BYTES (s);
1862 #endif
1863 data->string = NULL;
1865 /* Reset the strings's `data' member so that we
1866 know it's free. */
1867 s->data = NULL;
1869 /* Put the string on the free-list. */
1870 NEXT_FREE_LISP_STRING (s) = string_free_list;
1871 string_free_list = s;
1872 ++nfree;
1875 else
1877 /* S was on the free-list before. Put it there again. */
1878 NEXT_FREE_LISP_STRING (s) = string_free_list;
1879 string_free_list = s;
1880 ++nfree;
1884 /* Free blocks that contain free Lisp_Strings only, except
1885 the first two of them. */
1886 if (nfree == STRING_BLOCK_SIZE
1887 && total_free_strings > STRING_BLOCK_SIZE)
1889 lisp_free (b);
1890 string_free_list = free_list_before;
1892 else
1894 total_free_strings += nfree;
1895 b->next = live_blocks;
1896 live_blocks = b;
1900 check_string_free_list ();
1902 string_blocks = live_blocks;
1903 free_large_strings ();
1904 compact_small_strings ();
1906 check_string_free_list ();
1910 /* Free dead large strings. */
1912 static void
1913 free_large_strings (void)
1915 struct sblock *b, *next;
1916 struct sblock *live_blocks = NULL;
1918 for (b = large_sblocks; b; b = next)
1920 next = b->next;
1922 if (b->data[0].string == NULL)
1923 lisp_free (b);
1924 else
1926 b->next = live_blocks;
1927 live_blocks = b;
1931 large_sblocks = live_blocks;
1935 /* Compact data of small strings. Free sblocks that don't contain
1936 data of live strings after compaction. */
1938 static void
1939 compact_small_strings (void)
1941 struct sblock *b, *tb, *next;
1942 sdata *from, *to, *end, *tb_end;
1943 sdata *to_end, *from_end;
1945 /* TB is the sblock we copy to, TO is the sdata within TB we copy
1946 to, and TB_END is the end of TB. */
1947 tb = oldest_sblock;
1948 tb_end = (sdata *) ((char *) tb + SBLOCK_SIZE);
1949 to = tb->data;
1951 /* Step through the blocks from the oldest to the youngest. We
1952 expect that old blocks will stabilize over time, so that less
1953 copying will happen this way. */
1954 for (b = oldest_sblock; b; b = b->next)
1956 end = b->next_free;
1957 eassert ((char *) end <= (char *) b + SBLOCK_SIZE);
1959 for (from = b->data; from < end; from = from_end)
1961 /* Compute the next FROM here because copying below may
1962 overwrite data we need to compute it. */
1963 ptrdiff_t nbytes;
1964 struct Lisp_String *s = from->string;
1966 #ifdef GC_CHECK_STRING_BYTES
1967 /* Check that the string size recorded in the string is the
1968 same as the one recorded in the sdata structure. */
1969 if (s && string_bytes (s) != SDATA_NBYTES (from))
1970 emacs_abort ();
1971 #endif /* GC_CHECK_STRING_BYTES */
1973 nbytes = s ? STRING_BYTES (s) : SDATA_NBYTES (from);
1974 eassert (nbytes <= LARGE_STRING_BYTES);
1976 nbytes = SDATA_SIZE (nbytes);
1977 from_end = (sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
1979 #ifdef GC_CHECK_STRING_OVERRUN
1980 if (memcmp (string_overrun_cookie,
1981 (char *) from_end - GC_STRING_OVERRUN_COOKIE_SIZE,
1982 GC_STRING_OVERRUN_COOKIE_SIZE))
1983 emacs_abort ();
1984 #endif
1986 /* Non-NULL S means it's alive. Copy its data. */
1987 if (s)
1989 /* If TB is full, proceed with the next sblock. */
1990 to_end = (sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
1991 if (to_end > tb_end)
1993 tb->next_free = to;
1994 tb = tb->next;
1995 tb_end = (sdata *) ((char *) tb + SBLOCK_SIZE);
1996 to = tb->data;
1997 to_end = (sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
2000 /* Copy, and update the string's `data' pointer. */
2001 if (from != to)
2003 eassert (tb != b || to < from);
2004 memmove (to, from, nbytes + GC_STRING_EXTRA);
2005 to->string->data = SDATA_DATA (to);
2008 /* Advance past the sdata we copied to. */
2009 to = to_end;
2014 /* The rest of the sblocks following TB don't contain live data, so
2015 we can free them. */
2016 for (b = tb->next; b; b = next)
2018 next = b->next;
2019 lisp_free (b);
2022 tb->next_free = to;
2023 tb->next = NULL;
2024 current_sblock = tb;
2027 void
2028 string_overflow (void)
2030 error ("Maximum string size exceeded");
2033 DEFUN ("make-string", Fmake_string, Smake_string, 2, 2, 0,
2034 doc: /* Return a newly created string of length LENGTH, with INIT in each element.
2035 LENGTH must be an integer.
2036 INIT must be an integer that represents a character. */)
2037 (Lisp_Object length, Lisp_Object init)
2039 register Lisp_Object val;
2040 int c;
2041 EMACS_INT nbytes;
2043 CHECK_NATNUM (length);
2044 CHECK_CHARACTER (init);
2046 c = XFASTINT (init);
2047 if (ASCII_CHAR_P (c))
2049 nbytes = XINT (length);
2050 val = make_uninit_string (nbytes);
2051 memset (SDATA (val), c, nbytes);
2052 SDATA (val)[nbytes] = 0;
2054 else
2056 unsigned char str[MAX_MULTIBYTE_LENGTH];
2057 ptrdiff_t len = CHAR_STRING (c, str);
2058 EMACS_INT string_len = XINT (length);
2059 unsigned char *p, *beg, *end;
2061 if (string_len > STRING_BYTES_MAX / len)
2062 string_overflow ();
2063 nbytes = len * string_len;
2064 val = make_uninit_multibyte_string (string_len, nbytes);
2065 for (beg = SDATA (val), p = beg, end = beg + nbytes; p < end; p += len)
2067 /* First time we just copy `str' to the data of `val'. */
2068 if (p == beg)
2069 memcpy (p, str, len);
2070 else
2072 /* Next time we copy largest possible chunk from
2073 initialized to uninitialized part of `val'. */
2074 len = min (p - beg, end - p);
2075 memcpy (p, beg, len);
2078 *p = 0;
2081 return val;
2084 /* Fill A with 1 bits if INIT is non-nil, and with 0 bits otherwise.
2085 Return A. */
2087 Lisp_Object
2088 bool_vector_fill (Lisp_Object a, Lisp_Object init)
2090 EMACS_INT nbits = bool_vector_size (a);
2091 if (0 < nbits)
2093 unsigned char *data = bool_vector_uchar_data (a);
2094 int pattern = NILP (init) ? 0 : (1 << BOOL_VECTOR_BITS_PER_CHAR) - 1;
2095 ptrdiff_t nbytes = bool_vector_bytes (nbits);
2096 int last_mask = ~ (~0 << ((nbits - 1) % BOOL_VECTOR_BITS_PER_CHAR + 1));
2097 memset (data, pattern, nbytes - 1);
2098 data[nbytes - 1] = pattern & last_mask;
2100 return a;
2103 /* Return a newly allocated, uninitialized bool vector of size NBITS. */
2105 Lisp_Object
2106 make_uninit_bool_vector (EMACS_INT nbits)
2108 Lisp_Object val;
2109 EMACS_INT words = bool_vector_words (nbits);
2110 EMACS_INT word_bytes = words * sizeof (bits_word);
2111 EMACS_INT needed_elements = ((bool_header_size - header_size + word_bytes
2112 + word_size - 1)
2113 / word_size);
2114 struct Lisp_Bool_Vector *p
2115 = (struct Lisp_Bool_Vector *) allocate_vector (needed_elements);
2116 XSETVECTOR (val, p);
2117 XSETPVECTYPESIZE (XVECTOR (val), PVEC_BOOL_VECTOR, 0, 0);
2118 p->size = nbits;
2120 /* Clear padding at the end. */
2121 if (words)
2122 p->data[words - 1] = 0;
2124 return val;
2127 DEFUN ("make-bool-vector", Fmake_bool_vector, Smake_bool_vector, 2, 2, 0,
2128 doc: /* Return a new bool-vector of length LENGTH, using INIT for each element.
2129 LENGTH must be a number. INIT matters only in whether it is t or nil. */)
2130 (Lisp_Object length, Lisp_Object init)
2132 Lisp_Object val;
2134 CHECK_NATNUM (length);
2135 val = make_uninit_bool_vector (XFASTINT (length));
2136 return bool_vector_fill (val, init);
2140 /* Make a string from NBYTES bytes at CONTENTS, and compute the number
2141 of characters from the contents. This string may be unibyte or
2142 multibyte, depending on the contents. */
2144 Lisp_Object
2145 make_string (const char *contents, ptrdiff_t nbytes)
2147 register Lisp_Object val;
2148 ptrdiff_t nchars, multibyte_nbytes;
2150 parse_str_as_multibyte ((const unsigned char *) contents, nbytes,
2151 &nchars, &multibyte_nbytes);
2152 if (nbytes == nchars || nbytes != multibyte_nbytes)
2153 /* CONTENTS contains no multibyte sequences or contains an invalid
2154 multibyte sequence. We must make unibyte string. */
2155 val = make_unibyte_string (contents, nbytes);
2156 else
2157 val = make_multibyte_string (contents, nchars, nbytes);
2158 return val;
2162 /* Make an unibyte string from LENGTH bytes at CONTENTS. */
2164 Lisp_Object
2165 make_unibyte_string (const char *contents, ptrdiff_t length)
2167 register Lisp_Object val;
2168 val = make_uninit_string (length);
2169 memcpy (SDATA (val), contents, length);
2170 return val;
2174 /* Make a multibyte string from NCHARS characters occupying NBYTES
2175 bytes at CONTENTS. */
2177 Lisp_Object
2178 make_multibyte_string (const char *contents,
2179 ptrdiff_t nchars, ptrdiff_t nbytes)
2181 register Lisp_Object val;
2182 val = make_uninit_multibyte_string (nchars, nbytes);
2183 memcpy (SDATA (val), contents, nbytes);
2184 return val;
2188 /* Make a string from NCHARS characters occupying NBYTES bytes at
2189 CONTENTS. It is a multibyte string if NBYTES != NCHARS. */
2191 Lisp_Object
2192 make_string_from_bytes (const char *contents,
2193 ptrdiff_t nchars, ptrdiff_t nbytes)
2195 register Lisp_Object val;
2196 val = make_uninit_multibyte_string (nchars, nbytes);
2197 memcpy (SDATA (val), contents, nbytes);
2198 if (SBYTES (val) == SCHARS (val))
2199 STRING_SET_UNIBYTE (val);
2200 return val;
2204 /* Make a string from NCHARS characters occupying NBYTES bytes at
2205 CONTENTS. The argument MULTIBYTE controls whether to label the
2206 string as multibyte. If NCHARS is negative, it counts the number of
2207 characters by itself. */
2209 Lisp_Object
2210 make_specified_string (const char *contents,
2211 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
2213 Lisp_Object val;
2215 if (nchars < 0)
2217 if (multibyte)
2218 nchars = multibyte_chars_in_text ((const unsigned char *) contents,
2219 nbytes);
2220 else
2221 nchars = nbytes;
2223 val = make_uninit_multibyte_string (nchars, nbytes);
2224 memcpy (SDATA (val), contents, nbytes);
2225 if (!multibyte)
2226 STRING_SET_UNIBYTE (val);
2227 return val;
2231 /* Return an unibyte Lisp_String set up to hold LENGTH characters
2232 occupying LENGTH bytes. */
2234 Lisp_Object
2235 make_uninit_string (EMACS_INT length)
2237 Lisp_Object val;
2239 if (!length)
2240 return empty_unibyte_string;
2241 val = make_uninit_multibyte_string (length, length);
2242 STRING_SET_UNIBYTE (val);
2243 return val;
2247 /* Return a multibyte Lisp_String set up to hold NCHARS characters
2248 which occupy NBYTES bytes. */
2250 Lisp_Object
2251 make_uninit_multibyte_string (EMACS_INT nchars, EMACS_INT nbytes)
2253 Lisp_Object string;
2254 struct Lisp_String *s;
2256 if (nchars < 0)
2257 emacs_abort ();
2258 if (!nbytes)
2259 return empty_multibyte_string;
2261 s = allocate_string ();
2262 s->intervals = NULL;
2263 allocate_string_data (s, nchars, nbytes);
2264 XSETSTRING (string, s);
2265 string_chars_consed += nbytes;
2266 return string;
2269 /* Print arguments to BUF according to a FORMAT, then return
2270 a Lisp_String initialized with the data from BUF. */
2272 Lisp_Object
2273 make_formatted_string (char *buf, const char *format, ...)
2275 va_list ap;
2276 int length;
2278 va_start (ap, format);
2279 length = vsprintf (buf, format, ap);
2280 va_end (ap);
2281 return make_string (buf, length);
2285 /***********************************************************************
2286 Float Allocation
2287 ***********************************************************************/
2289 /* We store float cells inside of float_blocks, allocating a new
2290 float_block with malloc whenever necessary. Float cells reclaimed
2291 by GC are put on a free list to be reallocated before allocating
2292 any new float cells from the latest float_block. */
2294 #define FLOAT_BLOCK_SIZE \
2295 (((BLOCK_BYTES - sizeof (struct float_block *) \
2296 /* The compiler might add padding at the end. */ \
2297 - (sizeof (struct Lisp_Float) - sizeof (int))) * CHAR_BIT) \
2298 / (sizeof (struct Lisp_Float) * CHAR_BIT + 1))
2300 #define GETMARKBIT(block,n) \
2301 (((block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2302 >> ((n) % (sizeof (int) * CHAR_BIT))) \
2303 & 1)
2305 #define SETMARKBIT(block,n) \
2306 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2307 |= 1 << ((n) % (sizeof (int) * CHAR_BIT))
2309 #define UNSETMARKBIT(block,n) \
2310 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2311 &= ~(1 << ((n) % (sizeof (int) * CHAR_BIT)))
2313 #define FLOAT_BLOCK(fptr) \
2314 ((struct float_block *) (((uintptr_t) (fptr)) & ~(BLOCK_ALIGN - 1)))
2316 #define FLOAT_INDEX(fptr) \
2317 ((((uintptr_t) (fptr)) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Float))
2319 struct float_block
2321 /* Place `floats' at the beginning, to ease up FLOAT_INDEX's job. */
2322 struct Lisp_Float floats[FLOAT_BLOCK_SIZE];
2323 int gcmarkbits[1 + FLOAT_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2324 struct float_block *next;
2327 #define FLOAT_MARKED_P(fptr) \
2328 GETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2330 #define FLOAT_MARK(fptr) \
2331 SETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2333 #define FLOAT_UNMARK(fptr) \
2334 UNSETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2336 /* Current float_block. */
2338 static struct float_block *float_block;
2340 /* Index of first unused Lisp_Float in the current float_block. */
2342 static int float_block_index = FLOAT_BLOCK_SIZE;
2344 /* Free-list of Lisp_Floats. */
2346 static struct Lisp_Float *float_free_list;
2348 /* Return a new float object with value FLOAT_VALUE. */
2350 Lisp_Object
2351 make_float (double float_value)
2353 register Lisp_Object val;
2355 MALLOC_BLOCK_INPUT;
2357 if (float_free_list)
2359 /* We use the data field for chaining the free list
2360 so that we won't use the same field that has the mark bit. */
2361 XSETFLOAT (val, float_free_list);
2362 float_free_list = float_free_list->u.chain;
2364 else
2366 if (float_block_index == FLOAT_BLOCK_SIZE)
2368 struct float_block *new
2369 = lisp_align_malloc (sizeof *new, MEM_TYPE_FLOAT);
2370 new->next = float_block;
2371 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2372 float_block = new;
2373 float_block_index = 0;
2374 total_free_floats += FLOAT_BLOCK_SIZE;
2376 XSETFLOAT (val, &float_block->floats[float_block_index]);
2377 float_block_index++;
2380 MALLOC_UNBLOCK_INPUT;
2382 XFLOAT_INIT (val, float_value);
2383 eassert (!FLOAT_MARKED_P (XFLOAT (val)));
2384 consing_since_gc += sizeof (struct Lisp_Float);
2385 floats_consed++;
2386 total_free_floats--;
2387 return val;
2392 /***********************************************************************
2393 Cons Allocation
2394 ***********************************************************************/
2396 /* We store cons cells inside of cons_blocks, allocating a new
2397 cons_block with malloc whenever necessary. Cons cells reclaimed by
2398 GC are put on a free list to be reallocated before allocating
2399 any new cons cells from the latest cons_block. */
2401 #define CONS_BLOCK_SIZE \
2402 (((BLOCK_BYTES - sizeof (struct cons_block *) \
2403 /* The compiler might add padding at the end. */ \
2404 - (sizeof (struct Lisp_Cons) - sizeof (int))) * CHAR_BIT) \
2405 / (sizeof (struct Lisp_Cons) * CHAR_BIT + 1))
2407 #define CONS_BLOCK(fptr) \
2408 ((struct cons_block *) ((uintptr_t) (fptr) & ~(BLOCK_ALIGN - 1)))
2410 #define CONS_INDEX(fptr) \
2411 (((uintptr_t) (fptr) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Cons))
2413 struct cons_block
2415 /* Place `conses' at the beginning, to ease up CONS_INDEX's job. */
2416 struct Lisp_Cons conses[CONS_BLOCK_SIZE];
2417 int gcmarkbits[1 + CONS_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2418 struct cons_block *next;
2421 #define CONS_MARKED_P(fptr) \
2422 GETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2424 #define CONS_MARK(fptr) \
2425 SETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2427 #define CONS_UNMARK(fptr) \
2428 UNSETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2430 /* Current cons_block. */
2432 static struct cons_block *cons_block;
2434 /* Index of first unused Lisp_Cons in the current block. */
2436 static int cons_block_index = CONS_BLOCK_SIZE;
2438 /* Free-list of Lisp_Cons structures. */
2440 static struct Lisp_Cons *cons_free_list;
2442 /* Explicitly free a cons cell by putting it on the free-list. */
2444 void
2445 free_cons (struct Lisp_Cons *ptr)
2447 ptr->u.chain = cons_free_list;
2448 #if GC_MARK_STACK
2449 ptr->car = Vdead;
2450 #endif
2451 cons_free_list = ptr;
2452 consing_since_gc -= sizeof *ptr;
2453 total_free_conses++;
2456 DEFUN ("cons", Fcons, Scons, 2, 2, 0,
2457 doc: /* Create a new cons, give it CAR and CDR as components, and return it. */)
2458 (Lisp_Object car, Lisp_Object cdr)
2460 register Lisp_Object val;
2462 MALLOC_BLOCK_INPUT;
2464 if (cons_free_list)
2466 /* We use the cdr for chaining the free list
2467 so that we won't use the same field that has the mark bit. */
2468 XSETCONS (val, cons_free_list);
2469 cons_free_list = cons_free_list->u.chain;
2471 else
2473 if (cons_block_index == CONS_BLOCK_SIZE)
2475 struct cons_block *new
2476 = lisp_align_malloc (sizeof *new, MEM_TYPE_CONS);
2477 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2478 new->next = cons_block;
2479 cons_block = new;
2480 cons_block_index = 0;
2481 total_free_conses += CONS_BLOCK_SIZE;
2483 XSETCONS (val, &cons_block->conses[cons_block_index]);
2484 cons_block_index++;
2487 MALLOC_UNBLOCK_INPUT;
2489 XSETCAR (val, car);
2490 XSETCDR (val, cdr);
2491 eassert (!CONS_MARKED_P (XCONS (val)));
2492 consing_since_gc += sizeof (struct Lisp_Cons);
2493 total_free_conses--;
2494 cons_cells_consed++;
2495 return val;
2498 #ifdef GC_CHECK_CONS_LIST
2499 /* Get an error now if there's any junk in the cons free list. */
2500 void
2501 check_cons_list (void)
2503 struct Lisp_Cons *tail = cons_free_list;
2505 while (tail)
2506 tail = tail->u.chain;
2508 #endif
2510 /* Make a list of 1, 2, 3, 4 or 5 specified objects. */
2512 Lisp_Object
2513 list1 (Lisp_Object arg1)
2515 return Fcons (arg1, Qnil);
2518 Lisp_Object
2519 list2 (Lisp_Object arg1, Lisp_Object arg2)
2521 return Fcons (arg1, Fcons (arg2, Qnil));
2525 Lisp_Object
2526 list3 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
2528 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Qnil)));
2532 Lisp_Object
2533 list4 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4)
2535 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4, Qnil))));
2539 Lisp_Object
2540 list5 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4, Lisp_Object arg5)
2542 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4,
2543 Fcons (arg5, Qnil)))));
2546 /* Make a list of COUNT Lisp_Objects, where ARG is the
2547 first one. Allocate conses from pure space if TYPE
2548 is CONSTYPE_PURE, or allocate as usual if type is CONSTYPE_HEAP. */
2550 Lisp_Object
2551 listn (enum constype type, ptrdiff_t count, Lisp_Object arg, ...)
2553 va_list ap;
2554 ptrdiff_t i;
2555 Lisp_Object val, *objp;
2557 /* Change to SAFE_ALLOCA if you hit this eassert. */
2558 eassert (count <= MAX_ALLOCA / word_size);
2560 objp = alloca (count * word_size);
2561 objp[0] = arg;
2562 va_start (ap, arg);
2563 for (i = 1; i < count; i++)
2564 objp[i] = va_arg (ap, Lisp_Object);
2565 va_end (ap);
2567 for (val = Qnil, i = count - 1; i >= 0; i--)
2569 if (type == CONSTYPE_PURE)
2570 val = pure_cons (objp[i], val);
2571 else if (type == CONSTYPE_HEAP)
2572 val = Fcons (objp[i], val);
2573 else
2574 emacs_abort ();
2576 return val;
2579 DEFUN ("list", Flist, Slist, 0, MANY, 0,
2580 doc: /* Return a newly created list with specified arguments as elements.
2581 Any number of arguments, even zero arguments, are allowed.
2582 usage: (list &rest OBJECTS) */)
2583 (ptrdiff_t nargs, Lisp_Object *args)
2585 register Lisp_Object val;
2586 val = Qnil;
2588 while (nargs > 0)
2590 nargs--;
2591 val = Fcons (args[nargs], val);
2593 return val;
2597 DEFUN ("make-list", Fmake_list, Smake_list, 2, 2, 0,
2598 doc: /* Return a newly created list of length LENGTH, with each element being INIT. */)
2599 (register Lisp_Object length, Lisp_Object init)
2601 register Lisp_Object val;
2602 register EMACS_INT size;
2604 CHECK_NATNUM (length);
2605 size = XFASTINT (length);
2607 val = Qnil;
2608 while (size > 0)
2610 val = Fcons (init, val);
2611 --size;
2613 if (size > 0)
2615 val = Fcons (init, val);
2616 --size;
2618 if (size > 0)
2620 val = Fcons (init, val);
2621 --size;
2623 if (size > 0)
2625 val = Fcons (init, val);
2626 --size;
2628 if (size > 0)
2630 val = Fcons (init, val);
2631 --size;
2637 QUIT;
2640 return val;
2645 /***********************************************************************
2646 Vector Allocation
2647 ***********************************************************************/
2649 /* Sometimes a vector's contents are merely a pointer internally used
2650 in vector allocation code. Usually you don't want to touch this. */
2652 static struct Lisp_Vector *
2653 next_vector (struct Lisp_Vector *v)
2655 return XUNTAG (v->contents[0], 0);
2658 static void
2659 set_next_vector (struct Lisp_Vector *v, struct Lisp_Vector *p)
2661 v->contents[0] = make_lisp_ptr (p, 0);
2664 /* This value is balanced well enough to avoid too much internal overhead
2665 for the most common cases; it's not required to be a power of two, but
2666 it's expected to be a mult-of-ROUNDUP_SIZE (see below). */
2668 #define VECTOR_BLOCK_SIZE 4096
2670 enum
2672 /* Alignment of struct Lisp_Vector objects. */
2673 vector_alignment = COMMON_MULTIPLE (ALIGNOF_STRUCT_LISP_VECTOR,
2674 USE_LSB_TAG ? GCALIGNMENT : 1),
2676 /* Vector size requests are a multiple of this. */
2677 roundup_size = COMMON_MULTIPLE (vector_alignment, word_size)
2680 /* Verify assumptions described above. */
2681 verify ((VECTOR_BLOCK_SIZE % roundup_size) == 0);
2682 verify (VECTOR_BLOCK_SIZE <= (1 << PSEUDOVECTOR_SIZE_BITS));
2684 /* Round up X to nearest mult-of-ROUNDUP_SIZE --- use at compile time. */
2685 #define vroundup_ct(x) ROUNDUP (x, roundup_size)
2686 /* Round up X to nearest mult-of-ROUNDUP_SIZE --- use at runtime. */
2687 #define vroundup(x) (eassume ((x) >= 0), vroundup_ct (x))
2689 /* Rounding helps to maintain alignment constraints if USE_LSB_TAG. */
2691 #define VECTOR_BLOCK_BYTES (VECTOR_BLOCK_SIZE - vroundup_ct (sizeof (void *)))
2693 /* Size of the minimal vector allocated from block. */
2695 #define VBLOCK_BYTES_MIN vroundup_ct (header_size + sizeof (Lisp_Object))
2697 /* Size of the largest vector allocated from block. */
2699 #define VBLOCK_BYTES_MAX \
2700 vroundup ((VECTOR_BLOCK_BYTES / 2) - word_size)
2702 /* We maintain one free list for each possible block-allocated
2703 vector size, and this is the number of free lists we have. */
2705 #define VECTOR_MAX_FREE_LIST_INDEX \
2706 ((VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN) / roundup_size + 1)
2708 /* Common shortcut to advance vector pointer over a block data. */
2710 #define ADVANCE(v, nbytes) ((struct Lisp_Vector *) ((char *) (v) + (nbytes)))
2712 /* Common shortcut to calculate NBYTES-vector index in VECTOR_FREE_LISTS. */
2714 #define VINDEX(nbytes) (((nbytes) - VBLOCK_BYTES_MIN) / roundup_size)
2716 /* Common shortcut to setup vector on a free list. */
2718 #define SETUP_ON_FREE_LIST(v, nbytes, tmp) \
2719 do { \
2720 (tmp) = ((nbytes - header_size) / word_size); \
2721 XSETPVECTYPESIZE (v, PVEC_FREE, 0, (tmp)); \
2722 eassert ((nbytes) % roundup_size == 0); \
2723 (tmp) = VINDEX (nbytes); \
2724 eassert ((tmp) < VECTOR_MAX_FREE_LIST_INDEX); \
2725 set_next_vector (v, vector_free_lists[tmp]); \
2726 vector_free_lists[tmp] = (v); \
2727 total_free_vector_slots += (nbytes) / word_size; \
2728 } while (0)
2730 /* This internal type is used to maintain the list of large vectors
2731 which are allocated at their own, e.g. outside of vector blocks.
2733 struct large_vector itself cannot contain a struct Lisp_Vector, as
2734 the latter contains a flexible array member and C99 does not allow
2735 such structs to be nested. Instead, each struct large_vector
2736 object LV is followed by a struct Lisp_Vector, which is at offset
2737 large_vector_offset from LV, and whose address is therefore
2738 large_vector_vec (&LV). */
2740 struct large_vector
2742 struct large_vector *next;
2745 enum
2747 large_vector_offset = ROUNDUP (sizeof (struct large_vector), vector_alignment)
2750 static struct Lisp_Vector *
2751 large_vector_vec (struct large_vector *p)
2753 return (struct Lisp_Vector *) ((char *) p + large_vector_offset);
2756 /* This internal type is used to maintain an underlying storage
2757 for small vectors. */
2759 struct vector_block
2761 char data[VECTOR_BLOCK_BYTES];
2762 struct vector_block *next;
2765 /* Chain of vector blocks. */
2767 static struct vector_block *vector_blocks;
2769 /* Vector free lists, where NTH item points to a chain of free
2770 vectors of the same NBYTES size, so NTH == VINDEX (NBYTES). */
2772 static struct Lisp_Vector *vector_free_lists[VECTOR_MAX_FREE_LIST_INDEX];
2774 /* Singly-linked list of large vectors. */
2776 static struct large_vector *large_vectors;
2778 /* The only vector with 0 slots, allocated from pure space. */
2780 Lisp_Object zero_vector;
2782 /* Number of live vectors. */
2784 static EMACS_INT total_vectors;
2786 /* Total size of live and free vectors, in Lisp_Object units. */
2788 static EMACS_INT total_vector_slots, total_free_vector_slots;
2790 /* Get a new vector block. */
2792 static struct vector_block *
2793 allocate_vector_block (void)
2795 struct vector_block *block = xmalloc (sizeof *block);
2797 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
2798 mem_insert (block->data, block->data + VECTOR_BLOCK_BYTES,
2799 MEM_TYPE_VECTOR_BLOCK);
2800 #endif
2802 block->next = vector_blocks;
2803 vector_blocks = block;
2804 return block;
2807 /* Called once to initialize vector allocation. */
2809 static void
2810 init_vectors (void)
2812 zero_vector = make_pure_vector (0);
2815 /* Allocate vector from a vector block. */
2817 static struct Lisp_Vector *
2818 allocate_vector_from_block (size_t nbytes)
2820 struct Lisp_Vector *vector;
2821 struct vector_block *block;
2822 size_t index, restbytes;
2824 eassert (VBLOCK_BYTES_MIN <= nbytes && nbytes <= VBLOCK_BYTES_MAX);
2825 eassert (nbytes % roundup_size == 0);
2827 /* First, try to allocate from a free list
2828 containing vectors of the requested size. */
2829 index = VINDEX (nbytes);
2830 if (vector_free_lists[index])
2832 vector = vector_free_lists[index];
2833 vector_free_lists[index] = next_vector (vector);
2834 total_free_vector_slots -= nbytes / word_size;
2835 return vector;
2838 /* Next, check free lists containing larger vectors. Since
2839 we will split the result, we should have remaining space
2840 large enough to use for one-slot vector at least. */
2841 for (index = VINDEX (nbytes + VBLOCK_BYTES_MIN);
2842 index < VECTOR_MAX_FREE_LIST_INDEX; index++)
2843 if (vector_free_lists[index])
2845 /* This vector is larger than requested. */
2846 vector = vector_free_lists[index];
2847 vector_free_lists[index] = next_vector (vector);
2848 total_free_vector_slots -= nbytes / word_size;
2850 /* Excess bytes are used for the smaller vector,
2851 which should be set on an appropriate free list. */
2852 restbytes = index * roundup_size + VBLOCK_BYTES_MIN - nbytes;
2853 eassert (restbytes % roundup_size == 0);
2854 SETUP_ON_FREE_LIST (ADVANCE (vector, nbytes), restbytes, index);
2855 return vector;
2858 /* Finally, need a new vector block. */
2859 block = allocate_vector_block ();
2861 /* New vector will be at the beginning of this block. */
2862 vector = (struct Lisp_Vector *) block->data;
2864 /* If the rest of space from this block is large enough
2865 for one-slot vector at least, set up it on a free list. */
2866 restbytes = VECTOR_BLOCK_BYTES - nbytes;
2867 if (restbytes >= VBLOCK_BYTES_MIN)
2869 eassert (restbytes % roundup_size == 0);
2870 SETUP_ON_FREE_LIST (ADVANCE (vector, nbytes), restbytes, index);
2872 return vector;
2875 /* Nonzero if VECTOR pointer is valid pointer inside BLOCK. */
2877 #define VECTOR_IN_BLOCK(vector, block) \
2878 ((char *) (vector) <= (block)->data \
2879 + VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN)
2881 /* Return the memory footprint of V in bytes. */
2883 static ptrdiff_t
2884 vector_nbytes (struct Lisp_Vector *v)
2886 ptrdiff_t size = v->header.size & ~ARRAY_MARK_FLAG;
2887 ptrdiff_t nwords;
2889 if (size & PSEUDOVECTOR_FLAG)
2891 if (PSEUDOVECTOR_TYPEP (&v->header, PVEC_BOOL_VECTOR))
2893 struct Lisp_Bool_Vector *bv = (struct Lisp_Bool_Vector *) v;
2894 ptrdiff_t word_bytes = (bool_vector_words (bv->size)
2895 * sizeof (bits_word));
2896 ptrdiff_t boolvec_bytes = bool_header_size + word_bytes;
2897 verify (header_size <= bool_header_size);
2898 nwords = (boolvec_bytes - header_size + word_size - 1) / word_size;
2900 else
2901 nwords = ((size & PSEUDOVECTOR_SIZE_MASK)
2902 + ((size & PSEUDOVECTOR_REST_MASK)
2903 >> PSEUDOVECTOR_SIZE_BITS));
2905 else
2906 nwords = size;
2907 return vroundup (header_size + word_size * nwords);
2910 /* Release extra resources still in use by VECTOR, which may be any
2911 vector-like object. For now, this is used just to free data in
2912 font objects. */
2914 static void
2915 cleanup_vector (struct Lisp_Vector *vector)
2917 if (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FONT)
2918 && ((vector->header.size & PSEUDOVECTOR_SIZE_MASK)
2919 == FONT_OBJECT_MAX))
2921 /* Attempt to catch subtle bugs like Bug#16140. */
2922 eassert (valid_font_driver (((struct font *) vector)->driver));
2923 ((struct font *) vector)->driver->close ((struct font *) vector);
2927 /* Reclaim space used by unmarked vectors. */
2929 static void
2930 sweep_vectors (void)
2932 struct vector_block *block, **bprev = &vector_blocks;
2933 struct large_vector *lv, **lvprev = &large_vectors;
2934 struct Lisp_Vector *vector, *next;
2936 total_vectors = total_vector_slots = total_free_vector_slots = 0;
2937 memset (vector_free_lists, 0, sizeof (vector_free_lists));
2939 /* Looking through vector blocks. */
2941 for (block = vector_blocks; block; block = *bprev)
2943 bool free_this_block = 0;
2944 ptrdiff_t nbytes;
2946 for (vector = (struct Lisp_Vector *) block->data;
2947 VECTOR_IN_BLOCK (vector, block); vector = next)
2949 if (VECTOR_MARKED_P (vector))
2951 VECTOR_UNMARK (vector);
2952 total_vectors++;
2953 nbytes = vector_nbytes (vector);
2954 total_vector_slots += nbytes / word_size;
2955 next = ADVANCE (vector, nbytes);
2957 else
2959 ptrdiff_t total_bytes;
2961 cleanup_vector (vector);
2962 nbytes = vector_nbytes (vector);
2963 total_bytes = nbytes;
2964 next = ADVANCE (vector, nbytes);
2966 /* While NEXT is not marked, try to coalesce with VECTOR,
2967 thus making VECTOR of the largest possible size. */
2969 while (VECTOR_IN_BLOCK (next, block))
2971 if (VECTOR_MARKED_P (next))
2972 break;
2973 cleanup_vector (next);
2974 nbytes = vector_nbytes (next);
2975 total_bytes += nbytes;
2976 next = ADVANCE (next, nbytes);
2979 eassert (total_bytes % roundup_size == 0);
2981 if (vector == (struct Lisp_Vector *) block->data
2982 && !VECTOR_IN_BLOCK (next, block))
2983 /* This block should be freed because all of it's
2984 space was coalesced into the only free vector. */
2985 free_this_block = 1;
2986 else
2988 size_t tmp;
2989 SETUP_ON_FREE_LIST (vector, total_bytes, tmp);
2994 if (free_this_block)
2996 *bprev = block->next;
2997 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
2998 mem_delete (mem_find (block->data));
2999 #endif
3000 xfree (block);
3002 else
3003 bprev = &block->next;
3006 /* Sweep large vectors. */
3008 for (lv = large_vectors; lv; lv = *lvprev)
3010 vector = large_vector_vec (lv);
3011 if (VECTOR_MARKED_P (vector))
3013 VECTOR_UNMARK (vector);
3014 total_vectors++;
3015 if (vector->header.size & PSEUDOVECTOR_FLAG)
3017 /* All non-bool pseudovectors are small enough to be allocated
3018 from vector blocks. This code should be redesigned if some
3019 pseudovector type grows beyond VBLOCK_BYTES_MAX. */
3020 eassert (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_BOOL_VECTOR));
3021 total_vector_slots += vector_nbytes (vector) / word_size;
3023 else
3024 total_vector_slots
3025 += header_size / word_size + vector->header.size;
3026 lvprev = &lv->next;
3028 else
3030 *lvprev = lv->next;
3031 lisp_free (lv);
3036 /* Value is a pointer to a newly allocated Lisp_Vector structure
3037 with room for LEN Lisp_Objects. */
3039 static struct Lisp_Vector *
3040 allocate_vectorlike (ptrdiff_t len)
3042 struct Lisp_Vector *p;
3044 MALLOC_BLOCK_INPUT;
3046 if (len == 0)
3047 p = XVECTOR (zero_vector);
3048 else
3050 size_t nbytes = header_size + len * word_size;
3052 #ifdef DOUG_LEA_MALLOC
3053 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
3054 because mapped region contents are not preserved in
3055 a dumped Emacs. */
3056 mallopt (M_MMAP_MAX, 0);
3057 #endif
3059 if (nbytes <= VBLOCK_BYTES_MAX)
3060 p = allocate_vector_from_block (vroundup (nbytes));
3061 else
3063 struct large_vector *lv
3064 = lisp_malloc ((large_vector_offset + header_size
3065 + len * word_size),
3066 MEM_TYPE_VECTORLIKE);
3067 lv->next = large_vectors;
3068 large_vectors = lv;
3069 p = large_vector_vec (lv);
3072 #ifdef DOUG_LEA_MALLOC
3073 /* Back to a reasonable maximum of mmap'ed areas. */
3074 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
3075 #endif
3077 consing_since_gc += nbytes;
3078 vector_cells_consed += len;
3081 MALLOC_UNBLOCK_INPUT;
3083 return p;
3087 /* Allocate a vector with LEN slots. */
3089 struct Lisp_Vector *
3090 allocate_vector (EMACS_INT len)
3092 struct Lisp_Vector *v;
3093 ptrdiff_t nbytes_max = min (PTRDIFF_MAX, SIZE_MAX);
3095 if (min ((nbytes_max - header_size) / word_size, MOST_POSITIVE_FIXNUM) < len)
3096 memory_full (SIZE_MAX);
3097 v = allocate_vectorlike (len);
3098 v->header.size = len;
3099 return v;
3103 /* Allocate other vector-like structures. */
3105 struct Lisp_Vector *
3106 allocate_pseudovector (int memlen, int lisplen, enum pvec_type tag)
3108 struct Lisp_Vector *v = allocate_vectorlike (memlen);
3109 int i;
3111 /* Catch bogus values. */
3112 eassert (tag <= PVEC_FONT);
3113 eassert (memlen - lisplen <= (1 << PSEUDOVECTOR_REST_BITS) - 1);
3114 eassert (lisplen <= (1 << PSEUDOVECTOR_SIZE_BITS) - 1);
3116 /* Only the first lisplen slots will be traced normally by the GC. */
3117 for (i = 0; i < lisplen; ++i)
3118 v->contents[i] = Qnil;
3120 XSETPVECTYPESIZE (v, tag, lisplen, memlen - lisplen);
3121 return v;
3124 struct buffer *
3125 allocate_buffer (void)
3127 struct buffer *b = lisp_malloc (sizeof *b, MEM_TYPE_BUFFER);
3129 BUFFER_PVEC_INIT (b);
3130 /* Put B on the chain of all buffers including killed ones. */
3131 b->next = all_buffers;
3132 all_buffers = b;
3133 /* Note that the rest fields of B are not initialized. */
3134 return b;
3137 struct Lisp_Hash_Table *
3138 allocate_hash_table (void)
3140 return ALLOCATE_PSEUDOVECTOR (struct Lisp_Hash_Table, count, PVEC_HASH_TABLE);
3143 struct window *
3144 allocate_window (void)
3146 struct window *w;
3148 w = ALLOCATE_PSEUDOVECTOR (struct window, current_matrix, PVEC_WINDOW);
3149 /* Users assumes that non-Lisp data is zeroed. */
3150 memset (&w->current_matrix, 0,
3151 sizeof (*w) - offsetof (struct window, current_matrix));
3152 return w;
3155 struct terminal *
3156 allocate_terminal (void)
3158 struct terminal *t;
3160 t = ALLOCATE_PSEUDOVECTOR (struct terminal, next_terminal, PVEC_TERMINAL);
3161 /* Users assumes that non-Lisp data is zeroed. */
3162 memset (&t->next_terminal, 0,
3163 sizeof (*t) - offsetof (struct terminal, next_terminal));
3164 return t;
3167 struct frame *
3168 allocate_frame (void)
3170 struct frame *f;
3172 f = ALLOCATE_PSEUDOVECTOR (struct frame, face_cache, PVEC_FRAME);
3173 /* Users assumes that non-Lisp data is zeroed. */
3174 memset (&f->face_cache, 0,
3175 sizeof (*f) - offsetof (struct frame, face_cache));
3176 return f;
3179 struct Lisp_Process *
3180 allocate_process (void)
3182 struct Lisp_Process *p;
3184 p = ALLOCATE_PSEUDOVECTOR (struct Lisp_Process, pid, PVEC_PROCESS);
3185 /* Users assumes that non-Lisp data is zeroed. */
3186 memset (&p->pid, 0,
3187 sizeof (*p) - offsetof (struct Lisp_Process, pid));
3188 return p;
3191 DEFUN ("make-vector", Fmake_vector, Smake_vector, 2, 2, 0,
3192 doc: /* Return a newly created vector of length LENGTH, with each element being INIT.
3193 See also the function `vector'. */)
3194 (register Lisp_Object length, Lisp_Object init)
3196 Lisp_Object vector;
3197 register ptrdiff_t sizei;
3198 register ptrdiff_t i;
3199 register struct Lisp_Vector *p;
3201 CHECK_NATNUM (length);
3203 p = allocate_vector (XFASTINT (length));
3204 sizei = XFASTINT (length);
3205 for (i = 0; i < sizei; i++)
3206 p->contents[i] = init;
3208 XSETVECTOR (vector, p);
3209 return vector;
3213 DEFUN ("vector", Fvector, Svector, 0, MANY, 0,
3214 doc: /* Return a newly created vector with specified arguments as elements.
3215 Any number of arguments, even zero arguments, are allowed.
3216 usage: (vector &rest OBJECTS) */)
3217 (ptrdiff_t nargs, Lisp_Object *args)
3219 ptrdiff_t i;
3220 register Lisp_Object val = make_uninit_vector (nargs);
3221 register struct Lisp_Vector *p = XVECTOR (val);
3223 for (i = 0; i < nargs; i++)
3224 p->contents[i] = args[i];
3225 return val;
3228 void
3229 make_byte_code (struct Lisp_Vector *v)
3231 /* Don't allow the global zero_vector to become a byte code object. */
3232 eassert (0 < v->header.size);
3234 if (v->header.size > 1 && STRINGP (v->contents[1])
3235 && STRING_MULTIBYTE (v->contents[1]))
3236 /* BYTECODE-STRING must have been produced by Emacs 20.2 or the
3237 earlier because they produced a raw 8-bit string for byte-code
3238 and now such a byte-code string is loaded as multibyte while
3239 raw 8-bit characters converted to multibyte form. Thus, now we
3240 must convert them back to the original unibyte form. */
3241 v->contents[1] = Fstring_as_unibyte (v->contents[1]);
3242 XSETPVECTYPE (v, PVEC_COMPILED);
3245 DEFUN ("make-byte-code", Fmake_byte_code, Smake_byte_code, 4, MANY, 0,
3246 doc: /* Create a byte-code object with specified arguments as elements.
3247 The arguments should be the ARGLIST, bytecode-string BYTE-CODE, constant
3248 vector CONSTANTS, maximum stack size DEPTH, (optional) DOCSTRING,
3249 and (optional) INTERACTIVE-SPEC.
3250 The first four arguments are required; at most six have any
3251 significance.
3252 The ARGLIST can be either like the one of `lambda', in which case the arguments
3253 will be dynamically bound before executing the byte code, or it can be an
3254 integer of the form NNNNNNNRMMMMMMM where the 7bit MMMMMMM specifies the
3255 minimum number of arguments, the 7-bit NNNNNNN specifies the maximum number
3256 of arguments (ignoring &rest) and the R bit specifies whether there is a &rest
3257 argument to catch the left-over arguments. If such an integer is used, the
3258 arguments will not be dynamically bound but will be instead pushed on the
3259 stack before executing the byte-code.
3260 usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INTERACTIVE-SPEC &rest ELEMENTS) */)
3261 (ptrdiff_t nargs, Lisp_Object *args)
3263 ptrdiff_t i;
3264 register Lisp_Object val = make_uninit_vector (nargs);
3265 register struct Lisp_Vector *p = XVECTOR (val);
3267 /* We used to purecopy everything here, if purify-flag was set. This worked
3268 OK for Emacs-23, but with Emacs-24's lexical binding code, it can be
3269 dangerous, since make-byte-code is used during execution to build
3270 closures, so any closure built during the preload phase would end up
3271 copied into pure space, including its free variables, which is sometimes
3272 just wasteful and other times plainly wrong (e.g. those free vars may want
3273 to be setcar'd). */
3275 for (i = 0; i < nargs; i++)
3276 p->contents[i] = args[i];
3277 make_byte_code (p);
3278 XSETCOMPILED (val, p);
3279 return val;
3284 /***********************************************************************
3285 Symbol Allocation
3286 ***********************************************************************/
3288 /* Like struct Lisp_Symbol, but padded so that the size is a multiple
3289 of the required alignment if LSB tags are used. */
3291 union aligned_Lisp_Symbol
3293 struct Lisp_Symbol s;
3294 #if USE_LSB_TAG
3295 unsigned char c[(sizeof (struct Lisp_Symbol) + GCALIGNMENT - 1)
3296 & -GCALIGNMENT];
3297 #endif
3300 /* Each symbol_block is just under 1020 bytes long, since malloc
3301 really allocates in units of powers of two and uses 4 bytes for its
3302 own overhead. */
3304 #define SYMBOL_BLOCK_SIZE \
3305 ((1020 - sizeof (struct symbol_block *)) / sizeof (union aligned_Lisp_Symbol))
3307 struct symbol_block
3309 /* Place `symbols' first, to preserve alignment. */
3310 union aligned_Lisp_Symbol symbols[SYMBOL_BLOCK_SIZE];
3311 struct symbol_block *next;
3314 /* Current symbol block and index of first unused Lisp_Symbol
3315 structure in it. */
3317 static struct symbol_block *symbol_block;
3318 static int symbol_block_index = SYMBOL_BLOCK_SIZE;
3319 /* Pointer to the first symbol_block that contains pinned symbols.
3320 Tests for 24.4 showed that at dump-time, Emacs contains about 15K symbols,
3321 10K of which are pinned (and all but 250 of them are interned in obarray),
3322 whereas a "typical session" has in the order of 30K symbols.
3323 `symbol_block_pinned' lets mark_pinned_symbols scan only 15K symbols rather
3324 than 30K to find the 10K symbols we need to mark. */
3325 static struct symbol_block *symbol_block_pinned;
3327 /* List of free symbols. */
3329 static struct Lisp_Symbol *symbol_free_list;
3331 static void
3332 set_symbol_name (Lisp_Object sym, Lisp_Object name)
3334 XSYMBOL (sym)->name = name;
3337 DEFUN ("make-symbol", Fmake_symbol, Smake_symbol, 1, 1, 0,
3338 doc: /* Return a newly allocated uninterned symbol whose name is NAME.
3339 Its value is void, and its function definition and property list are nil. */)
3340 (Lisp_Object name)
3342 register Lisp_Object val;
3343 register struct Lisp_Symbol *p;
3345 CHECK_STRING (name);
3347 MALLOC_BLOCK_INPUT;
3349 if (symbol_free_list)
3351 XSETSYMBOL (val, symbol_free_list);
3352 symbol_free_list = symbol_free_list->next;
3354 else
3356 if (symbol_block_index == SYMBOL_BLOCK_SIZE)
3358 struct symbol_block *new
3359 = lisp_malloc (sizeof *new, MEM_TYPE_SYMBOL);
3360 new->next = symbol_block;
3361 symbol_block = new;
3362 symbol_block_index = 0;
3363 total_free_symbols += SYMBOL_BLOCK_SIZE;
3365 XSETSYMBOL (val, &symbol_block->symbols[symbol_block_index].s);
3366 symbol_block_index++;
3369 MALLOC_UNBLOCK_INPUT;
3371 p = XSYMBOL (val);
3372 set_symbol_name (val, name);
3373 set_symbol_plist (val, Qnil);
3374 p->redirect = SYMBOL_PLAINVAL;
3375 SET_SYMBOL_VAL (p, Qunbound);
3376 set_symbol_function (val, Qnil);
3377 set_symbol_next (val, NULL);
3378 p->gcmarkbit = false;
3379 p->interned = SYMBOL_UNINTERNED;
3380 p->constant = 0;
3381 p->declared_special = false;
3382 p->pinned = false;
3383 consing_since_gc += sizeof (struct Lisp_Symbol);
3384 symbols_consed++;
3385 total_free_symbols--;
3386 return val;
3391 /***********************************************************************
3392 Marker (Misc) Allocation
3393 ***********************************************************************/
3395 /* Like union Lisp_Misc, but padded so that its size is a multiple of
3396 the required alignment when LSB tags are used. */
3398 union aligned_Lisp_Misc
3400 union Lisp_Misc m;
3401 #if USE_LSB_TAG
3402 unsigned char c[(sizeof (union Lisp_Misc) + GCALIGNMENT - 1)
3403 & -GCALIGNMENT];
3404 #endif
3407 /* Allocation of markers and other objects that share that structure.
3408 Works like allocation of conses. */
3410 #define MARKER_BLOCK_SIZE \
3411 ((1020 - sizeof (struct marker_block *)) / sizeof (union aligned_Lisp_Misc))
3413 struct marker_block
3415 /* Place `markers' first, to preserve alignment. */
3416 union aligned_Lisp_Misc markers[MARKER_BLOCK_SIZE];
3417 struct marker_block *next;
3420 static struct marker_block *marker_block;
3421 static int marker_block_index = MARKER_BLOCK_SIZE;
3423 static union Lisp_Misc *marker_free_list;
3425 /* Return a newly allocated Lisp_Misc object of specified TYPE. */
3427 static Lisp_Object
3428 allocate_misc (enum Lisp_Misc_Type type)
3430 Lisp_Object val;
3432 MALLOC_BLOCK_INPUT;
3434 if (marker_free_list)
3436 XSETMISC (val, marker_free_list);
3437 marker_free_list = marker_free_list->u_free.chain;
3439 else
3441 if (marker_block_index == MARKER_BLOCK_SIZE)
3443 struct marker_block *new = lisp_malloc (sizeof *new, MEM_TYPE_MISC);
3444 new->next = marker_block;
3445 marker_block = new;
3446 marker_block_index = 0;
3447 total_free_markers += MARKER_BLOCK_SIZE;
3449 XSETMISC (val, &marker_block->markers[marker_block_index].m);
3450 marker_block_index++;
3453 MALLOC_UNBLOCK_INPUT;
3455 --total_free_markers;
3456 consing_since_gc += sizeof (union Lisp_Misc);
3457 misc_objects_consed++;
3458 XMISCANY (val)->type = type;
3459 XMISCANY (val)->gcmarkbit = 0;
3460 return val;
3463 /* Free a Lisp_Misc object. */
3465 void
3466 free_misc (Lisp_Object misc)
3468 XMISCANY (misc)->type = Lisp_Misc_Free;
3469 XMISC (misc)->u_free.chain = marker_free_list;
3470 marker_free_list = XMISC (misc);
3471 consing_since_gc -= sizeof (union Lisp_Misc);
3472 total_free_markers++;
3475 /* Verify properties of Lisp_Save_Value's representation
3476 that are assumed here and elsewhere. */
3478 verify (SAVE_UNUSED == 0);
3479 verify (((SAVE_INTEGER | SAVE_POINTER | SAVE_FUNCPOINTER | SAVE_OBJECT)
3480 >> SAVE_SLOT_BITS)
3481 == 0);
3483 /* Return Lisp_Save_Value objects for the various combinations
3484 that callers need. */
3486 Lisp_Object
3487 make_save_int_int_int (ptrdiff_t a, ptrdiff_t b, ptrdiff_t c)
3489 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3490 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3491 p->save_type = SAVE_TYPE_INT_INT_INT;
3492 p->data[0].integer = a;
3493 p->data[1].integer = b;
3494 p->data[2].integer = c;
3495 return val;
3498 Lisp_Object
3499 make_save_obj_obj_obj_obj (Lisp_Object a, Lisp_Object b, Lisp_Object c,
3500 Lisp_Object d)
3502 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3503 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3504 p->save_type = SAVE_TYPE_OBJ_OBJ_OBJ_OBJ;
3505 p->data[0].object = a;
3506 p->data[1].object = b;
3507 p->data[2].object = c;
3508 p->data[3].object = d;
3509 return val;
3512 Lisp_Object
3513 make_save_ptr (void *a)
3515 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3516 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3517 p->save_type = SAVE_POINTER;
3518 p->data[0].pointer = a;
3519 return val;
3522 Lisp_Object
3523 make_save_ptr_int (void *a, ptrdiff_t b)
3525 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3526 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3527 p->save_type = SAVE_TYPE_PTR_INT;
3528 p->data[0].pointer = a;
3529 p->data[1].integer = b;
3530 return val;
3533 #if ! (defined USE_X_TOOLKIT || defined USE_GTK)
3534 Lisp_Object
3535 make_save_ptr_ptr (void *a, void *b)
3537 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3538 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3539 p->save_type = SAVE_TYPE_PTR_PTR;
3540 p->data[0].pointer = a;
3541 p->data[1].pointer = b;
3542 return val;
3544 #endif
3546 Lisp_Object
3547 make_save_funcptr_ptr_obj (void (*a) (void), void *b, Lisp_Object c)
3549 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3550 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3551 p->save_type = SAVE_TYPE_FUNCPTR_PTR_OBJ;
3552 p->data[0].funcpointer = a;
3553 p->data[1].pointer = b;
3554 p->data[2].object = c;
3555 return val;
3558 /* Return a Lisp_Save_Value object that represents an array A
3559 of N Lisp objects. */
3561 Lisp_Object
3562 make_save_memory (Lisp_Object *a, ptrdiff_t n)
3564 Lisp_Object val = allocate_misc (Lisp_Misc_Save_Value);
3565 struct Lisp_Save_Value *p = XSAVE_VALUE (val);
3566 p->save_type = SAVE_TYPE_MEMORY;
3567 p->data[0].pointer = a;
3568 p->data[1].integer = n;
3569 return val;
3572 /* Free a Lisp_Save_Value object. Do not use this function
3573 if SAVE contains pointer other than returned by xmalloc. */
3575 void
3576 free_save_value (Lisp_Object save)
3578 xfree (XSAVE_POINTER (save, 0));
3579 free_misc (save);
3582 /* Return a Lisp_Misc_Overlay object with specified START, END and PLIST. */
3584 Lisp_Object
3585 build_overlay (Lisp_Object start, Lisp_Object end, Lisp_Object plist)
3587 register Lisp_Object overlay;
3589 overlay = allocate_misc (Lisp_Misc_Overlay);
3590 OVERLAY_START (overlay) = start;
3591 OVERLAY_END (overlay) = end;
3592 set_overlay_plist (overlay, plist);
3593 XOVERLAY (overlay)->next = NULL;
3594 return overlay;
3597 DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
3598 doc: /* Return a newly allocated marker which does not point at any place. */)
3599 (void)
3601 register Lisp_Object val;
3602 register struct Lisp_Marker *p;
3604 val = allocate_misc (Lisp_Misc_Marker);
3605 p = XMARKER (val);
3606 p->buffer = 0;
3607 p->bytepos = 0;
3608 p->charpos = 0;
3609 p->next = NULL;
3610 p->insertion_type = 0;
3611 p->need_adjustment = 0;
3612 return val;
3615 /* Return a newly allocated marker which points into BUF
3616 at character position CHARPOS and byte position BYTEPOS. */
3618 Lisp_Object
3619 build_marker (struct buffer *buf, ptrdiff_t charpos, ptrdiff_t bytepos)
3621 Lisp_Object obj;
3622 struct Lisp_Marker *m;
3624 /* No dead buffers here. */
3625 eassert (BUFFER_LIVE_P (buf));
3627 /* Every character is at least one byte. */
3628 eassert (charpos <= bytepos);
3630 obj = allocate_misc (Lisp_Misc_Marker);
3631 m = XMARKER (obj);
3632 m->buffer = buf;
3633 m->charpos = charpos;
3634 m->bytepos = bytepos;
3635 m->insertion_type = 0;
3636 m->need_adjustment = 0;
3637 m->next = BUF_MARKERS (buf);
3638 BUF_MARKERS (buf) = m;
3639 return obj;
3642 /* Put MARKER back on the free list after using it temporarily. */
3644 void
3645 free_marker (Lisp_Object marker)
3647 unchain_marker (XMARKER (marker));
3648 free_misc (marker);
3652 /* Return a newly created vector or string with specified arguments as
3653 elements. If all the arguments are characters that can fit
3654 in a string of events, make a string; otherwise, make a vector.
3656 Any number of arguments, even zero arguments, are allowed. */
3658 Lisp_Object
3659 make_event_array (ptrdiff_t nargs, Lisp_Object *args)
3661 ptrdiff_t i;
3663 for (i = 0; i < nargs; i++)
3664 /* The things that fit in a string
3665 are characters that are in 0...127,
3666 after discarding the meta bit and all the bits above it. */
3667 if (!INTEGERP (args[i])
3668 || (XINT (args[i]) & ~(-CHAR_META)) >= 0200)
3669 return Fvector (nargs, args);
3671 /* Since the loop exited, we know that all the things in it are
3672 characters, so we can make a string. */
3674 Lisp_Object result;
3676 result = Fmake_string (make_number (nargs), make_number (0));
3677 for (i = 0; i < nargs; i++)
3679 SSET (result, i, XINT (args[i]));
3680 /* Move the meta bit to the right place for a string char. */
3681 if (XINT (args[i]) & CHAR_META)
3682 SSET (result, i, SREF (result, i) | 0x80);
3685 return result;
3691 /************************************************************************
3692 Memory Full Handling
3693 ************************************************************************/
3696 /* Called if malloc (NBYTES) returns zero. If NBYTES == SIZE_MAX,
3697 there may have been size_t overflow so that malloc was never
3698 called, or perhaps malloc was invoked successfully but the
3699 resulting pointer had problems fitting into a tagged EMACS_INT. In
3700 either case this counts as memory being full even though malloc did
3701 not fail. */
3703 void
3704 memory_full (size_t nbytes)
3706 /* Do not go into hysterics merely because a large request failed. */
3707 bool enough_free_memory = 0;
3708 if (SPARE_MEMORY < nbytes)
3710 void *p;
3712 MALLOC_BLOCK_INPUT;
3713 p = malloc (SPARE_MEMORY);
3714 if (p)
3716 free (p);
3717 enough_free_memory = 1;
3719 MALLOC_UNBLOCK_INPUT;
3722 if (! enough_free_memory)
3724 int i;
3726 Vmemory_full = Qt;
3728 memory_full_cons_threshold = sizeof (struct cons_block);
3730 /* The first time we get here, free the spare memory. */
3731 for (i = 0; i < sizeof (spare_memory) / sizeof (char *); i++)
3732 if (spare_memory[i])
3734 if (i == 0)
3735 free (spare_memory[i]);
3736 else if (i >= 1 && i <= 4)
3737 lisp_align_free (spare_memory[i]);
3738 else
3739 lisp_free (spare_memory[i]);
3740 spare_memory[i] = 0;
3744 /* This used to call error, but if we've run out of memory, we could
3745 get infinite recursion trying to build the string. */
3746 xsignal (Qnil, Vmemory_signal_data);
3749 /* If we released our reserve (due to running out of memory),
3750 and we have a fair amount free once again,
3751 try to set aside another reserve in case we run out once more.
3753 This is called when a relocatable block is freed in ralloc.c,
3754 and also directly from this file, in case we're not using ralloc.c. */
3756 void
3757 refill_memory_reserve (void)
3759 #ifndef SYSTEM_MALLOC
3760 if (spare_memory[0] == 0)
3761 spare_memory[0] = malloc (SPARE_MEMORY);
3762 if (spare_memory[1] == 0)
3763 spare_memory[1] = lisp_align_malloc (sizeof (struct cons_block),
3764 MEM_TYPE_SPARE);
3765 if (spare_memory[2] == 0)
3766 spare_memory[2] = lisp_align_malloc (sizeof (struct cons_block),
3767 MEM_TYPE_SPARE);
3768 if (spare_memory[3] == 0)
3769 spare_memory[3] = lisp_align_malloc (sizeof (struct cons_block),
3770 MEM_TYPE_SPARE);
3771 if (spare_memory[4] == 0)
3772 spare_memory[4] = lisp_align_malloc (sizeof (struct cons_block),
3773 MEM_TYPE_SPARE);
3774 if (spare_memory[5] == 0)
3775 spare_memory[5] = lisp_malloc (sizeof (struct string_block),
3776 MEM_TYPE_SPARE);
3777 if (spare_memory[6] == 0)
3778 spare_memory[6] = lisp_malloc (sizeof (struct string_block),
3779 MEM_TYPE_SPARE);
3780 if (spare_memory[0] && spare_memory[1] && spare_memory[5])
3781 Vmemory_full = Qnil;
3782 #endif
3785 /************************************************************************
3786 C Stack Marking
3787 ************************************************************************/
3789 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
3791 /* Conservative C stack marking requires a method to identify possibly
3792 live Lisp objects given a pointer value. We do this by keeping
3793 track of blocks of Lisp data that are allocated in a red-black tree
3794 (see also the comment of mem_node which is the type of nodes in
3795 that tree). Function lisp_malloc adds information for an allocated
3796 block to the red-black tree with calls to mem_insert, and function
3797 lisp_free removes it with mem_delete. Functions live_string_p etc
3798 call mem_find to lookup information about a given pointer in the
3799 tree, and use that to determine if the pointer points to a Lisp
3800 object or not. */
3802 /* Initialize this part of alloc.c. */
3804 static void
3805 mem_init (void)
3807 mem_z.left = mem_z.right = MEM_NIL;
3808 mem_z.parent = NULL;
3809 mem_z.color = MEM_BLACK;
3810 mem_z.start = mem_z.end = NULL;
3811 mem_root = MEM_NIL;
3815 /* Value is a pointer to the mem_node containing START. Value is
3816 MEM_NIL if there is no node in the tree containing START. */
3818 static struct mem_node *
3819 mem_find (void *start)
3821 struct mem_node *p;
3823 if (start < min_heap_address || start > max_heap_address)
3824 return MEM_NIL;
3826 /* Make the search always successful to speed up the loop below. */
3827 mem_z.start = start;
3828 mem_z.end = (char *) start + 1;
3830 p = mem_root;
3831 while (start < p->start || start >= p->end)
3832 p = start < p->start ? p->left : p->right;
3833 return p;
3837 /* Insert a new node into the tree for a block of memory with start
3838 address START, end address END, and type TYPE. Value is a
3839 pointer to the node that was inserted. */
3841 static struct mem_node *
3842 mem_insert (void *start, void *end, enum mem_type type)
3844 struct mem_node *c, *parent, *x;
3846 if (min_heap_address == NULL || start < min_heap_address)
3847 min_heap_address = start;
3848 if (max_heap_address == NULL || end > max_heap_address)
3849 max_heap_address = end;
3851 /* See where in the tree a node for START belongs. In this
3852 particular application, it shouldn't happen that a node is already
3853 present. For debugging purposes, let's check that. */
3854 c = mem_root;
3855 parent = NULL;
3857 #if GC_MARK_STACK != GC_MAKE_GCPROS_NOOPS
3859 while (c != MEM_NIL)
3861 if (start >= c->start && start < c->end)
3862 emacs_abort ();
3863 parent = c;
3864 c = start < c->start ? c->left : c->right;
3867 #else /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3869 while (c != MEM_NIL)
3871 parent = c;
3872 c = start < c->start ? c->left : c->right;
3875 #endif /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3877 /* Create a new node. */
3878 #ifdef GC_MALLOC_CHECK
3879 x = malloc (sizeof *x);
3880 if (x == NULL)
3881 emacs_abort ();
3882 #else
3883 x = xmalloc (sizeof *x);
3884 #endif
3885 x->start = start;
3886 x->end = end;
3887 x->type = type;
3888 x->parent = parent;
3889 x->left = x->right = MEM_NIL;
3890 x->color = MEM_RED;
3892 /* Insert it as child of PARENT or install it as root. */
3893 if (parent)
3895 if (start < parent->start)
3896 parent->left = x;
3897 else
3898 parent->right = x;
3900 else
3901 mem_root = x;
3903 /* Re-establish red-black tree properties. */
3904 mem_insert_fixup (x);
3906 return x;
3910 /* Re-establish the red-black properties of the tree, and thereby
3911 balance the tree, after node X has been inserted; X is always red. */
3913 static void
3914 mem_insert_fixup (struct mem_node *x)
3916 while (x != mem_root && x->parent->color == MEM_RED)
3918 /* X is red and its parent is red. This is a violation of
3919 red-black tree property #3. */
3921 if (x->parent == x->parent->parent->left)
3923 /* We're on the left side of our grandparent, and Y is our
3924 "uncle". */
3925 struct mem_node *y = x->parent->parent->right;
3927 if (y->color == MEM_RED)
3929 /* Uncle and parent are red but should be black because
3930 X is red. Change the colors accordingly and proceed
3931 with the grandparent. */
3932 x->parent->color = MEM_BLACK;
3933 y->color = MEM_BLACK;
3934 x->parent->parent->color = MEM_RED;
3935 x = x->parent->parent;
3937 else
3939 /* Parent and uncle have different colors; parent is
3940 red, uncle is black. */
3941 if (x == x->parent->right)
3943 x = x->parent;
3944 mem_rotate_left (x);
3947 x->parent->color = MEM_BLACK;
3948 x->parent->parent->color = MEM_RED;
3949 mem_rotate_right (x->parent->parent);
3952 else
3954 /* This is the symmetrical case of above. */
3955 struct mem_node *y = x->parent->parent->left;
3957 if (y->color == MEM_RED)
3959 x->parent->color = MEM_BLACK;
3960 y->color = MEM_BLACK;
3961 x->parent->parent->color = MEM_RED;
3962 x = x->parent->parent;
3964 else
3966 if (x == x->parent->left)
3968 x = x->parent;
3969 mem_rotate_right (x);
3972 x->parent->color = MEM_BLACK;
3973 x->parent->parent->color = MEM_RED;
3974 mem_rotate_left (x->parent->parent);
3979 /* The root may have been changed to red due to the algorithm. Set
3980 it to black so that property #5 is satisfied. */
3981 mem_root->color = MEM_BLACK;
3985 /* (x) (y)
3986 / \ / \
3987 a (y) ===> (x) c
3988 / \ / \
3989 b c a b */
3991 static void
3992 mem_rotate_left (struct mem_node *x)
3994 struct mem_node *y;
3996 /* Turn y's left sub-tree into x's right sub-tree. */
3997 y = x->right;
3998 x->right = y->left;
3999 if (y->left != MEM_NIL)
4000 y->left->parent = x;
4002 /* Y's parent was x's parent. */
4003 if (y != MEM_NIL)
4004 y->parent = x->parent;
4006 /* Get the parent to point to y instead of x. */
4007 if (x->parent)
4009 if (x == x->parent->left)
4010 x->parent->left = y;
4011 else
4012 x->parent->right = y;
4014 else
4015 mem_root = y;
4017 /* Put x on y's left. */
4018 y->left = x;
4019 if (x != MEM_NIL)
4020 x->parent = y;
4024 /* (x) (Y)
4025 / \ / \
4026 (y) c ===> a (x)
4027 / \ / \
4028 a b b c */
4030 static void
4031 mem_rotate_right (struct mem_node *x)
4033 struct mem_node *y = x->left;
4035 x->left = y->right;
4036 if (y->right != MEM_NIL)
4037 y->right->parent = x;
4039 if (y != MEM_NIL)
4040 y->parent = x->parent;
4041 if (x->parent)
4043 if (x == x->parent->right)
4044 x->parent->right = y;
4045 else
4046 x->parent->left = y;
4048 else
4049 mem_root = y;
4051 y->right = x;
4052 if (x != MEM_NIL)
4053 x->parent = y;
4057 /* Delete node Z from the tree. If Z is null or MEM_NIL, do nothing. */
4059 static void
4060 mem_delete (struct mem_node *z)
4062 struct mem_node *x, *y;
4064 if (!z || z == MEM_NIL)
4065 return;
4067 if (z->left == MEM_NIL || z->right == MEM_NIL)
4068 y = z;
4069 else
4071 y = z->right;
4072 while (y->left != MEM_NIL)
4073 y = y->left;
4076 if (y->left != MEM_NIL)
4077 x = y->left;
4078 else
4079 x = y->right;
4081 x->parent = y->parent;
4082 if (y->parent)
4084 if (y == y->parent->left)
4085 y->parent->left = x;
4086 else
4087 y->parent->right = x;
4089 else
4090 mem_root = x;
4092 if (y != z)
4094 z->start = y->start;
4095 z->end = y->end;
4096 z->type = y->type;
4099 if (y->color == MEM_BLACK)
4100 mem_delete_fixup (x);
4102 #ifdef GC_MALLOC_CHECK
4103 free (y);
4104 #else
4105 xfree (y);
4106 #endif
4110 /* Re-establish the red-black properties of the tree, after a
4111 deletion. */
4113 static void
4114 mem_delete_fixup (struct mem_node *x)
4116 while (x != mem_root && x->color == MEM_BLACK)
4118 if (x == x->parent->left)
4120 struct mem_node *w = x->parent->right;
4122 if (w->color == MEM_RED)
4124 w->color = MEM_BLACK;
4125 x->parent->color = MEM_RED;
4126 mem_rotate_left (x->parent);
4127 w = x->parent->right;
4130 if (w->left->color == MEM_BLACK && w->right->color == MEM_BLACK)
4132 w->color = MEM_RED;
4133 x = x->parent;
4135 else
4137 if (w->right->color == MEM_BLACK)
4139 w->left->color = MEM_BLACK;
4140 w->color = MEM_RED;
4141 mem_rotate_right (w);
4142 w = x->parent->right;
4144 w->color = x->parent->color;
4145 x->parent->color = MEM_BLACK;
4146 w->right->color = MEM_BLACK;
4147 mem_rotate_left (x->parent);
4148 x = mem_root;
4151 else
4153 struct mem_node *w = x->parent->left;
4155 if (w->color == MEM_RED)
4157 w->color = MEM_BLACK;
4158 x->parent->color = MEM_RED;
4159 mem_rotate_right (x->parent);
4160 w = x->parent->left;
4163 if (w->right->color == MEM_BLACK && w->left->color == MEM_BLACK)
4165 w->color = MEM_RED;
4166 x = x->parent;
4168 else
4170 if (w->left->color == MEM_BLACK)
4172 w->right->color = MEM_BLACK;
4173 w->color = MEM_RED;
4174 mem_rotate_left (w);
4175 w = x->parent->left;
4178 w->color = x->parent->color;
4179 x->parent->color = MEM_BLACK;
4180 w->left->color = MEM_BLACK;
4181 mem_rotate_right (x->parent);
4182 x = mem_root;
4187 x->color = MEM_BLACK;
4191 /* Value is non-zero if P is a pointer to a live Lisp string on
4192 the heap. M is a pointer to the mem_block for P. */
4194 static bool
4195 live_string_p (struct mem_node *m, void *p)
4197 if (m->type == MEM_TYPE_STRING)
4199 struct string_block *b = m->start;
4200 ptrdiff_t offset = (char *) p - (char *) &b->strings[0];
4202 /* P must point to the start of a Lisp_String structure, and it
4203 must not be on the free-list. */
4204 return (offset >= 0
4205 && offset % sizeof b->strings[0] == 0
4206 && offset < (STRING_BLOCK_SIZE * sizeof b->strings[0])
4207 && ((struct Lisp_String *) p)->data != NULL);
4209 else
4210 return 0;
4214 /* Value is non-zero if P is a pointer to a live Lisp cons on
4215 the heap. M is a pointer to the mem_block for P. */
4217 static bool
4218 live_cons_p (struct mem_node *m, void *p)
4220 if (m->type == MEM_TYPE_CONS)
4222 struct cons_block *b = m->start;
4223 ptrdiff_t offset = (char *) p - (char *) &b->conses[0];
4225 /* P must point to the start of a Lisp_Cons, not be
4226 one of the unused cells in the current cons block,
4227 and not be on the free-list. */
4228 return (offset >= 0
4229 && offset % sizeof b->conses[0] == 0
4230 && offset < (CONS_BLOCK_SIZE * sizeof b->conses[0])
4231 && (b != cons_block
4232 || offset / sizeof b->conses[0] < cons_block_index)
4233 && !EQ (((struct Lisp_Cons *) p)->car, Vdead));
4235 else
4236 return 0;
4240 /* Value is non-zero if P is a pointer to a live Lisp symbol on
4241 the heap. M is a pointer to the mem_block for P. */
4243 static bool
4244 live_symbol_p (struct mem_node *m, void *p)
4246 if (m->type == MEM_TYPE_SYMBOL)
4248 struct symbol_block *b = m->start;
4249 ptrdiff_t offset = (char *) p - (char *) &b->symbols[0];
4251 /* P must point to the start of a Lisp_Symbol, not be
4252 one of the unused cells in the current symbol block,
4253 and not be on the free-list. */
4254 return (offset >= 0
4255 && offset % sizeof b->symbols[0] == 0
4256 && offset < (SYMBOL_BLOCK_SIZE * sizeof b->symbols[0])
4257 && (b != symbol_block
4258 || offset / sizeof b->symbols[0] < symbol_block_index)
4259 && !EQ (((struct Lisp_Symbol *)p)->function, Vdead));
4261 else
4262 return 0;
4266 /* Value is non-zero if P is a pointer to a live Lisp float on
4267 the heap. M is a pointer to the mem_block for P. */
4269 static bool
4270 live_float_p (struct mem_node *m, void *p)
4272 if (m->type == MEM_TYPE_FLOAT)
4274 struct float_block *b = m->start;
4275 ptrdiff_t offset = (char *) p - (char *) &b->floats[0];
4277 /* P must point to the start of a Lisp_Float and not be
4278 one of the unused cells in the current float block. */
4279 return (offset >= 0
4280 && offset % sizeof b->floats[0] == 0
4281 && offset < (FLOAT_BLOCK_SIZE * sizeof b->floats[0])
4282 && (b != float_block
4283 || offset / sizeof b->floats[0] < float_block_index));
4285 else
4286 return 0;
4290 /* Value is non-zero if P is a pointer to a live Lisp Misc on
4291 the heap. M is a pointer to the mem_block for P. */
4293 static bool
4294 live_misc_p (struct mem_node *m, void *p)
4296 if (m->type == MEM_TYPE_MISC)
4298 struct marker_block *b = m->start;
4299 ptrdiff_t offset = (char *) p - (char *) &b->markers[0];
4301 /* P must point to the start of a Lisp_Misc, not be
4302 one of the unused cells in the current misc block,
4303 and not be on the free-list. */
4304 return (offset >= 0
4305 && offset % sizeof b->markers[0] == 0
4306 && offset < (MARKER_BLOCK_SIZE * sizeof b->markers[0])
4307 && (b != marker_block
4308 || offset / sizeof b->markers[0] < marker_block_index)
4309 && ((union Lisp_Misc *) p)->u_any.type != Lisp_Misc_Free);
4311 else
4312 return 0;
4316 /* Value is non-zero if P is a pointer to a live vector-like object.
4317 M is a pointer to the mem_block for P. */
4319 static bool
4320 live_vector_p (struct mem_node *m, void *p)
4322 if (m->type == MEM_TYPE_VECTOR_BLOCK)
4324 /* This memory node corresponds to a vector block. */
4325 struct vector_block *block = m->start;
4326 struct Lisp_Vector *vector = (struct Lisp_Vector *) block->data;
4328 /* P is in the block's allocation range. Scan the block
4329 up to P and see whether P points to the start of some
4330 vector which is not on a free list. FIXME: check whether
4331 some allocation patterns (probably a lot of short vectors)
4332 may cause a substantial overhead of this loop. */
4333 while (VECTOR_IN_BLOCK (vector, block)
4334 && vector <= (struct Lisp_Vector *) p)
4336 if (!PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FREE) && vector == p)
4337 return 1;
4338 else
4339 vector = ADVANCE (vector, vector_nbytes (vector));
4342 else if (m->type == MEM_TYPE_VECTORLIKE && p == large_vector_vec (m->start))
4343 /* This memory node corresponds to a large vector. */
4344 return 1;
4345 return 0;
4349 /* Value is non-zero if P is a pointer to a live buffer. M is a
4350 pointer to the mem_block for P. */
4352 static bool
4353 live_buffer_p (struct mem_node *m, void *p)
4355 /* P must point to the start of the block, and the buffer
4356 must not have been killed. */
4357 return (m->type == MEM_TYPE_BUFFER
4358 && p == m->start
4359 && !NILP (((struct buffer *) p)->INTERNAL_FIELD (name)));
4362 #endif /* GC_MARK_STACK || defined GC_MALLOC_CHECK */
4364 #if GC_MARK_STACK
4366 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4368 /* Currently not used, but may be called from gdb. */
4370 void dump_zombies (void) EXTERNALLY_VISIBLE;
4372 /* Array of objects that are kept alive because the C stack contains
4373 a pattern that looks like a reference to them. */
4375 #define MAX_ZOMBIES 10
4376 static Lisp_Object zombies[MAX_ZOMBIES];
4378 /* Number of zombie objects. */
4380 static EMACS_INT nzombies;
4382 /* Number of garbage collections. */
4384 static EMACS_INT ngcs;
4386 /* Average percentage of zombies per collection. */
4388 static double avg_zombies;
4390 /* Max. number of live and zombie objects. */
4392 static EMACS_INT max_live, max_zombies;
4394 /* Average number of live objects per GC. */
4396 static double avg_live;
4398 DEFUN ("gc-status", Fgc_status, Sgc_status, 0, 0, "",
4399 doc: /* Show information about live and zombie objects. */)
4400 (void)
4402 Lisp_Object args[8], zombie_list = Qnil;
4403 EMACS_INT i;
4404 for (i = 0; i < min (MAX_ZOMBIES, nzombies); i++)
4405 zombie_list = Fcons (zombies[i], zombie_list);
4406 args[0] = build_string ("%d GCs, avg live/zombies = %.2f/%.2f (%f%%), max %d/%d\nzombies: %S");
4407 args[1] = make_number (ngcs);
4408 args[2] = make_float (avg_live);
4409 args[3] = make_float (avg_zombies);
4410 args[4] = make_float (avg_zombies / avg_live / 100);
4411 args[5] = make_number (max_live);
4412 args[6] = make_number (max_zombies);
4413 args[7] = zombie_list;
4414 return Fmessage (8, args);
4417 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4420 /* Mark OBJ if we can prove it's a Lisp_Object. */
4422 static void
4423 mark_maybe_object (Lisp_Object obj)
4425 void *po;
4426 struct mem_node *m;
4428 #if USE_VALGRIND
4429 if (valgrind_p)
4430 VALGRIND_MAKE_MEM_DEFINED (&obj, sizeof (obj));
4431 #endif
4433 if (INTEGERP (obj))
4434 return;
4436 po = (void *) XPNTR (obj);
4437 m = mem_find (po);
4439 if (m != MEM_NIL)
4441 bool mark_p = 0;
4443 switch (XTYPE (obj))
4445 case Lisp_String:
4446 mark_p = (live_string_p (m, po)
4447 && !STRING_MARKED_P ((struct Lisp_String *) po));
4448 break;
4450 case Lisp_Cons:
4451 mark_p = (live_cons_p (m, po) && !CONS_MARKED_P (XCONS (obj)));
4452 break;
4454 case Lisp_Symbol:
4455 mark_p = (live_symbol_p (m, po) && !XSYMBOL (obj)->gcmarkbit);
4456 break;
4458 case Lisp_Float:
4459 mark_p = (live_float_p (m, po) && !FLOAT_MARKED_P (XFLOAT (obj)));
4460 break;
4462 case Lisp_Vectorlike:
4463 /* Note: can't check BUFFERP before we know it's a
4464 buffer because checking that dereferences the pointer
4465 PO which might point anywhere. */
4466 if (live_vector_p (m, po))
4467 mark_p = !SUBRP (obj) && !VECTOR_MARKED_P (XVECTOR (obj));
4468 else if (live_buffer_p (m, po))
4469 mark_p = BUFFERP (obj) && !VECTOR_MARKED_P (XBUFFER (obj));
4470 break;
4472 case Lisp_Misc:
4473 mark_p = (live_misc_p (m, po) && !XMISCANY (obj)->gcmarkbit);
4474 break;
4476 default:
4477 break;
4480 if (mark_p)
4482 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4483 if (nzombies < MAX_ZOMBIES)
4484 zombies[nzombies] = obj;
4485 ++nzombies;
4486 #endif
4487 mark_object (obj);
4493 /* If P points to Lisp data, mark that as live if it isn't already
4494 marked. */
4496 static void
4497 mark_maybe_pointer (void *p)
4499 struct mem_node *m;
4501 #if USE_VALGRIND
4502 if (valgrind_p)
4503 VALGRIND_MAKE_MEM_DEFINED (&p, sizeof (p));
4504 #endif
4506 /* Quickly rule out some values which can't point to Lisp data.
4507 USE_LSB_TAG needs Lisp data to be aligned on multiples of GCALIGNMENT.
4508 Otherwise, assume that Lisp data is aligned on even addresses. */
4509 if ((intptr_t) p % (USE_LSB_TAG ? GCALIGNMENT : 2))
4510 return;
4512 m = mem_find (p);
4513 if (m != MEM_NIL)
4515 Lisp_Object obj = Qnil;
4517 switch (m->type)
4519 case MEM_TYPE_NON_LISP:
4520 case MEM_TYPE_SPARE:
4521 /* Nothing to do; not a pointer to Lisp memory. */
4522 break;
4524 case MEM_TYPE_BUFFER:
4525 if (live_buffer_p (m, p) && !VECTOR_MARKED_P ((struct buffer *)p))
4526 XSETVECTOR (obj, p);
4527 break;
4529 case MEM_TYPE_CONS:
4530 if (live_cons_p (m, p) && !CONS_MARKED_P ((struct Lisp_Cons *) p))
4531 XSETCONS (obj, p);
4532 break;
4534 case MEM_TYPE_STRING:
4535 if (live_string_p (m, p)
4536 && !STRING_MARKED_P ((struct Lisp_String *) p))
4537 XSETSTRING (obj, p);
4538 break;
4540 case MEM_TYPE_MISC:
4541 if (live_misc_p (m, p) && !((struct Lisp_Free *) p)->gcmarkbit)
4542 XSETMISC (obj, p);
4543 break;
4545 case MEM_TYPE_SYMBOL:
4546 if (live_symbol_p (m, p) && !((struct Lisp_Symbol *) p)->gcmarkbit)
4547 XSETSYMBOL (obj, p);
4548 break;
4550 case MEM_TYPE_FLOAT:
4551 if (live_float_p (m, p) && !FLOAT_MARKED_P (p))
4552 XSETFLOAT (obj, p);
4553 break;
4555 case MEM_TYPE_VECTORLIKE:
4556 case MEM_TYPE_VECTOR_BLOCK:
4557 if (live_vector_p (m, p))
4559 Lisp_Object tem;
4560 XSETVECTOR (tem, p);
4561 if (!SUBRP (tem) && !VECTOR_MARKED_P (XVECTOR (tem)))
4562 obj = tem;
4564 break;
4566 default:
4567 emacs_abort ();
4570 if (!NILP (obj))
4571 mark_object (obj);
4576 /* Alignment of pointer values. Use alignof, as it sometimes returns
4577 a smaller alignment than GCC's __alignof__ and mark_memory might
4578 miss objects if __alignof__ were used. */
4579 #define GC_POINTER_ALIGNMENT alignof (void *)
4581 /* Define POINTERS_MIGHT_HIDE_IN_OBJECTS to 1 if marking via C pointers does
4582 not suffice, which is the typical case. A host where a Lisp_Object is
4583 wider than a pointer might allocate a Lisp_Object in non-adjacent halves.
4584 If USE_LSB_TAG, the bottom half is not a valid pointer, but it should
4585 suffice to widen it to to a Lisp_Object and check it that way. */
4586 #if USE_LSB_TAG || VAL_MAX < UINTPTR_MAX
4587 # if !USE_LSB_TAG && VAL_MAX < UINTPTR_MAX >> GCTYPEBITS
4588 /* If tag bits straddle pointer-word boundaries, neither mark_maybe_pointer
4589 nor mark_maybe_object can follow the pointers. This should not occur on
4590 any practical porting target. */
4591 # error "MSB type bits straddle pointer-word boundaries"
4592 # endif
4593 /* Marking via C pointers does not suffice, because Lisp_Objects contain
4594 pointer words that hold pointers ORed with type bits. */
4595 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 1
4596 #else
4597 /* Marking via C pointers suffices, because Lisp_Objects contain pointer
4598 words that hold unmodified pointers. */
4599 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 0
4600 #endif
4602 /* Mark Lisp objects referenced from the address range START+OFFSET..END
4603 or END+OFFSET..START. */
4605 static void ATTRIBUTE_NO_SANITIZE_ADDRESS
4606 mark_memory (void *start, void *end)
4608 void **pp;
4609 int i;
4611 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4612 nzombies = 0;
4613 #endif
4615 /* Make START the pointer to the start of the memory region,
4616 if it isn't already. */
4617 if (end < start)
4619 void *tem = start;
4620 start = end;
4621 end = tem;
4624 /* Mark Lisp data pointed to. This is necessary because, in some
4625 situations, the C compiler optimizes Lisp objects away, so that
4626 only a pointer to them remains. Example:
4628 DEFUN ("testme", Ftestme, Stestme, 0, 0, 0, "")
4631 Lisp_Object obj = build_string ("test");
4632 struct Lisp_String *s = XSTRING (obj);
4633 Fgarbage_collect ();
4634 fprintf (stderr, "test `%s'\n", s->data);
4635 return Qnil;
4638 Here, `obj' isn't really used, and the compiler optimizes it
4639 away. The only reference to the life string is through the
4640 pointer `s'. */
4642 for (pp = start; (void *) pp < end; pp++)
4643 for (i = 0; i < sizeof *pp; i += GC_POINTER_ALIGNMENT)
4645 void *p = *(void **) ((char *) pp + i);
4646 mark_maybe_pointer (p);
4647 if (POINTERS_MIGHT_HIDE_IN_OBJECTS)
4648 mark_maybe_object (XIL ((intptr_t) p));
4652 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
4654 static bool setjmp_tested_p;
4655 static int longjmps_done;
4657 #define SETJMP_WILL_LIKELY_WORK "\
4659 Emacs garbage collector has been changed to use conservative stack\n\
4660 marking. Emacs has determined that the method it uses to do the\n\
4661 marking will likely work on your system, but this isn't sure.\n\
4663 If you are a system-programmer, or can get the help of a local wizard\n\
4664 who is, please take a look at the function mark_stack in alloc.c, and\n\
4665 verify that the methods used are appropriate for your system.\n\
4667 Please mail the result to <emacs-devel@gnu.org>.\n\
4670 #define SETJMP_WILL_NOT_WORK "\
4672 Emacs garbage collector has been changed to use conservative stack\n\
4673 marking. Emacs has determined that the default method it uses to do the\n\
4674 marking will not work on your system. We will need a system-dependent\n\
4675 solution for your system.\n\
4677 Please take a look at the function mark_stack in alloc.c, and\n\
4678 try to find a way to make it work on your system.\n\
4680 Note that you may get false negatives, depending on the compiler.\n\
4681 In particular, you need to use -O with GCC for this test.\n\
4683 Please mail the result to <emacs-devel@gnu.org>.\n\
4687 /* Perform a quick check if it looks like setjmp saves registers in a
4688 jmp_buf. Print a message to stderr saying so. When this test
4689 succeeds, this is _not_ a proof that setjmp is sufficient for
4690 conservative stack marking. Only the sources or a disassembly
4691 can prove that. */
4693 static void
4694 test_setjmp (void)
4696 char buf[10];
4697 register int x;
4698 sys_jmp_buf jbuf;
4700 /* Arrange for X to be put in a register. */
4701 sprintf (buf, "1");
4702 x = strlen (buf);
4703 x = 2 * x - 1;
4705 sys_setjmp (jbuf);
4706 if (longjmps_done == 1)
4708 /* Came here after the longjmp at the end of the function.
4710 If x == 1, the longjmp has restored the register to its
4711 value before the setjmp, and we can hope that setjmp
4712 saves all such registers in the jmp_buf, although that
4713 isn't sure.
4715 For other values of X, either something really strange is
4716 taking place, or the setjmp just didn't save the register. */
4718 if (x == 1)
4719 fprintf (stderr, SETJMP_WILL_LIKELY_WORK);
4720 else
4722 fprintf (stderr, SETJMP_WILL_NOT_WORK);
4723 exit (1);
4727 ++longjmps_done;
4728 x = 2;
4729 if (longjmps_done == 1)
4730 sys_longjmp (jbuf, 1);
4733 #endif /* not GC_SAVE_REGISTERS_ON_STACK && not GC_SETJMP_WORKS */
4736 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4738 /* Abort if anything GCPRO'd doesn't survive the GC. */
4740 static void
4741 check_gcpros (void)
4743 struct gcpro *p;
4744 ptrdiff_t i;
4746 for (p = gcprolist; p; p = p->next)
4747 for (i = 0; i < p->nvars; ++i)
4748 if (!survives_gc_p (p->var[i]))
4749 /* FIXME: It's not necessarily a bug. It might just be that the
4750 GCPRO is unnecessary or should release the object sooner. */
4751 emacs_abort ();
4754 #elif GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4756 void
4757 dump_zombies (void)
4759 int i;
4761 fprintf (stderr, "\nZombies kept alive = %"pI"d:\n", nzombies);
4762 for (i = 0; i < min (MAX_ZOMBIES, nzombies); ++i)
4764 fprintf (stderr, " %d = ", i);
4765 debug_print (zombies[i]);
4769 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4772 /* Mark live Lisp objects on the C stack.
4774 There are several system-dependent problems to consider when
4775 porting this to new architectures:
4777 Processor Registers
4779 We have to mark Lisp objects in CPU registers that can hold local
4780 variables or are used to pass parameters.
4782 If GC_SAVE_REGISTERS_ON_STACK is defined, it should expand to
4783 something that either saves relevant registers on the stack, or
4784 calls mark_maybe_object passing it each register's contents.
4786 If GC_SAVE_REGISTERS_ON_STACK is not defined, the current
4787 implementation assumes that calling setjmp saves registers we need
4788 to see in a jmp_buf which itself lies on the stack. This doesn't
4789 have to be true! It must be verified for each system, possibly
4790 by taking a look at the source code of setjmp.
4792 If __builtin_unwind_init is available (defined by GCC >= 2.8) we
4793 can use it as a machine independent method to store all registers
4794 to the stack. In this case the macros described in the previous
4795 two paragraphs are not used.
4797 Stack Layout
4799 Architectures differ in the way their processor stack is organized.
4800 For example, the stack might look like this
4802 +----------------+
4803 | Lisp_Object | size = 4
4804 +----------------+
4805 | something else | size = 2
4806 +----------------+
4807 | Lisp_Object | size = 4
4808 +----------------+
4809 | ... |
4811 In such a case, not every Lisp_Object will be aligned equally. To
4812 find all Lisp_Object on the stack it won't be sufficient to walk
4813 the stack in steps of 4 bytes. Instead, two passes will be
4814 necessary, one starting at the start of the stack, and a second
4815 pass starting at the start of the stack + 2. Likewise, if the
4816 minimal alignment of Lisp_Objects on the stack is 1, four passes
4817 would be necessary, each one starting with one byte more offset
4818 from the stack start. */
4820 static void
4821 mark_stack (void)
4823 void *end;
4825 #ifdef HAVE___BUILTIN_UNWIND_INIT
4826 /* Force callee-saved registers and register windows onto the stack.
4827 This is the preferred method if available, obviating the need for
4828 machine dependent methods. */
4829 __builtin_unwind_init ();
4830 end = &end;
4831 #else /* not HAVE___BUILTIN_UNWIND_INIT */
4832 #ifndef GC_SAVE_REGISTERS_ON_STACK
4833 /* jmp_buf may not be aligned enough on darwin-ppc64 */
4834 union aligned_jmpbuf {
4835 Lisp_Object o;
4836 sys_jmp_buf j;
4837 } j;
4838 volatile bool stack_grows_down_p = (char *) &j > (char *) stack_base;
4839 #endif
4840 /* This trick flushes the register windows so that all the state of
4841 the process is contained in the stack. */
4842 /* Fixme: Code in the Boehm GC suggests flushing (with `flushrs') is
4843 needed on ia64 too. See mach_dep.c, where it also says inline
4844 assembler doesn't work with relevant proprietary compilers. */
4845 #ifdef __sparc__
4846 #if defined (__sparc64__) && defined (__FreeBSD__)
4847 /* FreeBSD does not have a ta 3 handler. */
4848 asm ("flushw");
4849 #else
4850 asm ("ta 3");
4851 #endif
4852 #endif
4854 /* Save registers that we need to see on the stack. We need to see
4855 registers used to hold register variables and registers used to
4856 pass parameters. */
4857 #ifdef GC_SAVE_REGISTERS_ON_STACK
4858 GC_SAVE_REGISTERS_ON_STACK (end);
4859 #else /* not GC_SAVE_REGISTERS_ON_STACK */
4861 #ifndef GC_SETJMP_WORKS /* If it hasn't been checked yet that
4862 setjmp will definitely work, test it
4863 and print a message with the result
4864 of the test. */
4865 if (!setjmp_tested_p)
4867 setjmp_tested_p = 1;
4868 test_setjmp ();
4870 #endif /* GC_SETJMP_WORKS */
4872 sys_setjmp (j.j);
4873 end = stack_grows_down_p ? (char *) &j + sizeof j : (char *) &j;
4874 #endif /* not GC_SAVE_REGISTERS_ON_STACK */
4875 #endif /* not HAVE___BUILTIN_UNWIND_INIT */
4877 /* This assumes that the stack is a contiguous region in memory. If
4878 that's not the case, something has to be done here to iterate
4879 over the stack segments. */
4880 mark_memory (stack_base, end);
4882 /* Allow for marking a secondary stack, like the register stack on the
4883 ia64. */
4884 #ifdef GC_MARK_SECONDARY_STACK
4885 GC_MARK_SECONDARY_STACK ();
4886 #endif
4888 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4889 check_gcpros ();
4890 #endif
4893 #else /* GC_MARK_STACK == 0 */
4895 #define mark_maybe_object(obj) emacs_abort ()
4897 #endif /* GC_MARK_STACK != 0 */
4900 /* Determine whether it is safe to access memory at address P. */
4901 static int
4902 valid_pointer_p (void *p)
4904 #ifdef WINDOWSNT
4905 return w32_valid_pointer_p (p, 16);
4906 #else
4907 int fd[2];
4909 /* Obviously, we cannot just access it (we would SEGV trying), so we
4910 trick the o/s to tell us whether p is a valid pointer.
4911 Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
4912 not validate p in that case. */
4914 if (emacs_pipe (fd) == 0)
4916 bool valid = emacs_write (fd[1], p, 16) == 16;
4917 emacs_close (fd[1]);
4918 emacs_close (fd[0]);
4919 return valid;
4922 return -1;
4923 #endif
4926 /* Return 2 if OBJ is a killed or special buffer object, 1 if OBJ is a
4927 valid lisp object, 0 if OBJ is NOT a valid lisp object, or -1 if we
4928 cannot validate OBJ. This function can be quite slow, so its primary
4929 use is the manual debugging. The only exception is print_object, where
4930 we use it to check whether the memory referenced by the pointer of
4931 Lisp_Save_Value object contains valid objects. */
4934 valid_lisp_object_p (Lisp_Object obj)
4936 void *p;
4937 #if GC_MARK_STACK
4938 struct mem_node *m;
4939 #endif
4941 if (INTEGERP (obj))
4942 return 1;
4944 p = (void *) XPNTR (obj);
4945 if (PURE_POINTER_P (p))
4946 return 1;
4948 if (p == &buffer_defaults || p == &buffer_local_symbols)
4949 return 2;
4951 #if !GC_MARK_STACK
4952 return valid_pointer_p (p);
4953 #else
4955 m = mem_find (p);
4957 if (m == MEM_NIL)
4959 int valid = valid_pointer_p (p);
4960 if (valid <= 0)
4961 return valid;
4963 if (SUBRP (obj))
4964 return 1;
4966 return 0;
4969 switch (m->type)
4971 case MEM_TYPE_NON_LISP:
4972 case MEM_TYPE_SPARE:
4973 return 0;
4975 case MEM_TYPE_BUFFER:
4976 return live_buffer_p (m, p) ? 1 : 2;
4978 case MEM_TYPE_CONS:
4979 return live_cons_p (m, p);
4981 case MEM_TYPE_STRING:
4982 return live_string_p (m, p);
4984 case MEM_TYPE_MISC:
4985 return live_misc_p (m, p);
4987 case MEM_TYPE_SYMBOL:
4988 return live_symbol_p (m, p);
4990 case MEM_TYPE_FLOAT:
4991 return live_float_p (m, p);
4993 case MEM_TYPE_VECTORLIKE:
4994 case MEM_TYPE_VECTOR_BLOCK:
4995 return live_vector_p (m, p);
4997 default:
4998 break;
5001 return 0;
5002 #endif
5008 /***********************************************************************
5009 Pure Storage Management
5010 ***********************************************************************/
5012 /* Allocate room for SIZE bytes from pure Lisp storage and return a
5013 pointer to it. TYPE is the Lisp type for which the memory is
5014 allocated. TYPE < 0 means it's not used for a Lisp object. */
5016 static void *
5017 pure_alloc (size_t size, int type)
5019 void *result;
5020 #if USE_LSB_TAG
5021 size_t alignment = GCALIGNMENT;
5022 #else
5023 size_t alignment = alignof (EMACS_INT);
5025 /* Give Lisp_Floats an extra alignment. */
5026 if (type == Lisp_Float)
5027 alignment = alignof (struct Lisp_Float);
5028 #endif
5030 again:
5031 if (type >= 0)
5033 /* Allocate space for a Lisp object from the beginning of the free
5034 space with taking account of alignment. */
5035 result = ALIGN (purebeg + pure_bytes_used_lisp, alignment);
5036 pure_bytes_used_lisp = ((char *)result - (char *)purebeg) + size;
5038 else
5040 /* Allocate space for a non-Lisp object from the end of the free
5041 space. */
5042 pure_bytes_used_non_lisp += size;
5043 result = purebeg + pure_size - pure_bytes_used_non_lisp;
5045 pure_bytes_used = pure_bytes_used_lisp + pure_bytes_used_non_lisp;
5047 if (pure_bytes_used <= pure_size)
5048 return result;
5050 /* Don't allocate a large amount here,
5051 because it might get mmap'd and then its address
5052 might not be usable. */
5053 purebeg = xmalloc (10000);
5054 pure_size = 10000;
5055 pure_bytes_used_before_overflow += pure_bytes_used - size;
5056 pure_bytes_used = 0;
5057 pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
5058 goto again;
5062 /* Print a warning if PURESIZE is too small. */
5064 void
5065 check_pure_size (void)
5067 if (pure_bytes_used_before_overflow)
5068 message (("emacs:0:Pure Lisp storage overflow (approx. %"pI"d"
5069 " bytes needed)"),
5070 pure_bytes_used + pure_bytes_used_before_overflow);
5074 /* Find the byte sequence {DATA[0], ..., DATA[NBYTES-1], '\0'} from
5075 the non-Lisp data pool of the pure storage, and return its start
5076 address. Return NULL if not found. */
5078 static char *
5079 find_string_data_in_pure (const char *data, ptrdiff_t nbytes)
5081 int i;
5082 ptrdiff_t skip, bm_skip[256], last_char_skip, infinity, start, start_max;
5083 const unsigned char *p;
5084 char *non_lisp_beg;
5086 if (pure_bytes_used_non_lisp <= nbytes)
5087 return NULL;
5089 /* Set up the Boyer-Moore table. */
5090 skip = nbytes + 1;
5091 for (i = 0; i < 256; i++)
5092 bm_skip[i] = skip;
5094 p = (const unsigned char *) data;
5095 while (--skip > 0)
5096 bm_skip[*p++] = skip;
5098 last_char_skip = bm_skip['\0'];
5100 non_lisp_beg = purebeg + pure_size - pure_bytes_used_non_lisp;
5101 start_max = pure_bytes_used_non_lisp - (nbytes + 1);
5103 /* See the comments in the function `boyer_moore' (search.c) for the
5104 use of `infinity'. */
5105 infinity = pure_bytes_used_non_lisp + 1;
5106 bm_skip['\0'] = infinity;
5108 p = (const unsigned char *) non_lisp_beg + nbytes;
5109 start = 0;
5112 /* Check the last character (== '\0'). */
5115 start += bm_skip[*(p + start)];
5117 while (start <= start_max);
5119 if (start < infinity)
5120 /* Couldn't find the last character. */
5121 return NULL;
5123 /* No less than `infinity' means we could find the last
5124 character at `p[start - infinity]'. */
5125 start -= infinity;
5127 /* Check the remaining characters. */
5128 if (memcmp (data, non_lisp_beg + start, nbytes) == 0)
5129 /* Found. */
5130 return non_lisp_beg + start;
5132 start += last_char_skip;
5134 while (start <= start_max);
5136 return NULL;
5140 /* Return a string allocated in pure space. DATA is a buffer holding
5141 NCHARS characters, and NBYTES bytes of string data. MULTIBYTE
5142 means make the result string multibyte.
5144 Must get an error if pure storage is full, since if it cannot hold
5145 a large string it may be able to hold conses that point to that
5146 string; then the string is not protected from gc. */
5148 Lisp_Object
5149 make_pure_string (const char *data,
5150 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
5152 Lisp_Object string;
5153 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
5154 s->data = (unsigned char *) find_string_data_in_pure (data, nbytes);
5155 if (s->data == NULL)
5157 s->data = pure_alloc (nbytes + 1, -1);
5158 memcpy (s->data, data, nbytes);
5159 s->data[nbytes] = '\0';
5161 s->size = nchars;
5162 s->size_byte = multibyte ? nbytes : -1;
5163 s->intervals = NULL;
5164 XSETSTRING (string, s);
5165 return string;
5168 /* Return a string allocated in pure space. Do not
5169 allocate the string data, just point to DATA. */
5171 Lisp_Object
5172 make_pure_c_string (const char *data, ptrdiff_t nchars)
5174 Lisp_Object string;
5175 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
5176 s->size = nchars;
5177 s->size_byte = -1;
5178 s->data = (unsigned char *) data;
5179 s->intervals = NULL;
5180 XSETSTRING (string, s);
5181 return string;
5184 static Lisp_Object purecopy (Lisp_Object obj);
5186 /* Return a cons allocated from pure space. Give it pure copies
5187 of CAR as car and CDR as cdr. */
5189 Lisp_Object
5190 pure_cons (Lisp_Object car, Lisp_Object cdr)
5192 Lisp_Object new;
5193 struct Lisp_Cons *p = pure_alloc (sizeof *p, Lisp_Cons);
5194 XSETCONS (new, p);
5195 XSETCAR (new, purecopy (car));
5196 XSETCDR (new, purecopy (cdr));
5197 return new;
5201 /* Value is a float object with value NUM allocated from pure space. */
5203 static Lisp_Object
5204 make_pure_float (double num)
5206 Lisp_Object new;
5207 struct Lisp_Float *p = pure_alloc (sizeof *p, Lisp_Float);
5208 XSETFLOAT (new, p);
5209 XFLOAT_INIT (new, num);
5210 return new;
5214 /* Return a vector with room for LEN Lisp_Objects allocated from
5215 pure space. */
5217 static Lisp_Object
5218 make_pure_vector (ptrdiff_t len)
5220 Lisp_Object new;
5221 size_t size = header_size + len * word_size;
5222 struct Lisp_Vector *p = pure_alloc (size, Lisp_Vectorlike);
5223 XSETVECTOR (new, p);
5224 XVECTOR (new)->header.size = len;
5225 return new;
5229 DEFUN ("purecopy", Fpurecopy, Spurecopy, 1, 1, 0,
5230 doc: /* Make a copy of object OBJ in pure storage.
5231 Recursively copies contents of vectors and cons cells.
5232 Does not copy symbols. Copies strings without text properties. */)
5233 (register Lisp_Object obj)
5235 if (NILP (Vpurify_flag))
5236 return obj;
5237 else if (MARKERP (obj) || OVERLAYP (obj)
5238 || HASH_TABLE_P (obj) || SYMBOLP (obj))
5239 /* Can't purify those. */
5240 return obj;
5241 else
5242 return purecopy (obj);
5245 static Lisp_Object
5246 purecopy (Lisp_Object obj)
5248 if (PURE_POINTER_P (XPNTR (obj)) || INTEGERP (obj) || SUBRP (obj))
5249 return obj; /* Already pure. */
5251 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5253 Lisp_Object tmp = Fgethash (obj, Vpurify_flag, Qnil);
5254 if (!NILP (tmp))
5255 return tmp;
5258 if (CONSP (obj))
5259 obj = pure_cons (XCAR (obj), XCDR (obj));
5260 else if (FLOATP (obj))
5261 obj = make_pure_float (XFLOAT_DATA (obj));
5262 else if (STRINGP (obj))
5263 obj = make_pure_string (SSDATA (obj), SCHARS (obj),
5264 SBYTES (obj),
5265 STRING_MULTIBYTE (obj));
5266 else if (COMPILEDP (obj) || VECTORP (obj))
5268 register struct Lisp_Vector *vec;
5269 register ptrdiff_t i;
5270 ptrdiff_t size;
5272 size = ASIZE (obj);
5273 if (size & PSEUDOVECTOR_FLAG)
5274 size &= PSEUDOVECTOR_SIZE_MASK;
5275 vec = XVECTOR (make_pure_vector (size));
5276 for (i = 0; i < size; i++)
5277 vec->contents[i] = purecopy (AREF (obj, i));
5278 if (COMPILEDP (obj))
5280 XSETPVECTYPE (vec, PVEC_COMPILED);
5281 XSETCOMPILED (obj, vec);
5283 else
5284 XSETVECTOR (obj, vec);
5286 else if (SYMBOLP (obj))
5288 if (!XSYMBOL (obj)->pinned)
5289 { /* We can't purify them, but they appear in many pure objects.
5290 Mark them as `pinned' so we know to mark them at every GC cycle. */
5291 XSYMBOL (obj)->pinned = true;
5292 symbol_block_pinned = symbol_block;
5294 return obj;
5296 else
5298 Lisp_Object args[2];
5299 args[0] = build_pure_c_string ("Don't know how to purify: %S");
5300 args[1] = obj;
5301 Fsignal (Qerror, (Fcons (Fformat (2, args), Qnil)));
5304 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5305 Fputhash (obj, obj, Vpurify_flag);
5307 return obj;
5312 /***********************************************************************
5313 Protection from GC
5314 ***********************************************************************/
5316 /* Put an entry in staticvec, pointing at the variable with address
5317 VARADDRESS. */
5319 void
5320 staticpro (Lisp_Object *varaddress)
5322 if (staticidx >= NSTATICS)
5323 fatal ("NSTATICS too small; try increasing and recompiling Emacs.");
5324 staticvec[staticidx++] = varaddress;
5328 /***********************************************************************
5329 Protection from GC
5330 ***********************************************************************/
5332 /* Temporarily prevent garbage collection. */
5334 ptrdiff_t
5335 inhibit_garbage_collection (void)
5337 ptrdiff_t count = SPECPDL_INDEX ();
5339 specbind (Qgc_cons_threshold, make_number (MOST_POSITIVE_FIXNUM));
5340 return count;
5343 /* Used to avoid possible overflows when
5344 converting from C to Lisp integers. */
5346 static Lisp_Object
5347 bounded_number (EMACS_INT number)
5349 return make_number (min (MOST_POSITIVE_FIXNUM, number));
5352 /* Calculate total bytes of live objects. */
5354 static size_t
5355 total_bytes_of_live_objects (void)
5357 size_t tot = 0;
5358 tot += total_conses * sizeof (struct Lisp_Cons);
5359 tot += total_symbols * sizeof (struct Lisp_Symbol);
5360 tot += total_markers * sizeof (union Lisp_Misc);
5361 tot += total_string_bytes;
5362 tot += total_vector_slots * word_size;
5363 tot += total_floats * sizeof (struct Lisp_Float);
5364 tot += total_intervals * sizeof (struct interval);
5365 tot += total_strings * sizeof (struct Lisp_String);
5366 return tot;
5369 #ifdef HAVE_WINDOW_SYSTEM
5371 /* This code has a few issues on MS-Windows, see Bug#15876 and Bug#16140. */
5373 #if !defined (HAVE_NTGUI)
5375 /* Remove unmarked font-spec and font-entity objects from ENTRY, which is
5376 (DRIVER-TYPE NUM-FRAMES FONT-CACHE-DATA ...), and return changed entry. */
5378 static Lisp_Object
5379 compact_font_cache_entry (Lisp_Object entry)
5381 Lisp_Object tail, *prev = &entry;
5383 for (tail = entry; CONSP (tail); tail = XCDR (tail))
5385 bool drop = 0;
5386 Lisp_Object obj = XCAR (tail);
5388 /* Consider OBJ if it is (font-spec . [font-entity font-entity ...]). */
5389 if (CONSP (obj) && FONT_SPEC_P (XCAR (obj))
5390 && !VECTOR_MARKED_P (XFONT_SPEC (XCAR (obj)))
5391 && VECTORP (XCDR (obj)))
5393 ptrdiff_t i, size = ASIZE (XCDR (obj)) & ~ARRAY_MARK_FLAG;
5395 /* If font-spec is not marked, most likely all font-entities
5396 are not marked too. But we must be sure that nothing is
5397 marked within OBJ before we really drop it. */
5398 for (i = 0; i < size; i++)
5399 if (VECTOR_MARKED_P (XFONT_ENTITY (AREF (XCDR (obj), i))))
5400 break;
5402 if (i == size)
5403 drop = 1;
5405 if (drop)
5406 *prev = XCDR (tail);
5407 else
5408 prev = xcdr_addr (tail);
5410 return entry;
5413 #endif /* not HAVE_NTGUI */
5415 /* Compact font caches on all terminals and mark
5416 everything which is still here after compaction. */
5418 static void
5419 compact_font_caches (void)
5421 struct terminal *t;
5423 for (t = terminal_list; t; t = t->next_terminal)
5425 Lisp_Object cache = TERMINAL_FONT_CACHE (t);
5426 #if !defined (HAVE_NTGUI)
5427 if (CONSP (cache))
5429 Lisp_Object entry;
5431 for (entry = XCDR (cache); CONSP (entry); entry = XCDR (entry))
5432 XSETCAR (entry, compact_font_cache_entry (XCAR (entry)));
5434 #endif /* not HAVE_NTGUI */
5435 mark_object (cache);
5439 #else /* not HAVE_WINDOW_SYSTEM */
5441 #define compact_font_caches() (void)(0)
5443 #endif /* HAVE_WINDOW_SYSTEM */
5445 /* Remove (MARKER . DATA) entries with unmarked MARKER
5446 from buffer undo LIST and return changed list. */
5448 static Lisp_Object
5449 compact_undo_list (Lisp_Object list)
5451 Lisp_Object tail, *prev = &list;
5453 for (tail = list; CONSP (tail); tail = XCDR (tail))
5455 if (CONSP (XCAR (tail))
5456 && MARKERP (XCAR (XCAR (tail)))
5457 && !XMARKER (XCAR (XCAR (tail)))->gcmarkbit)
5458 *prev = XCDR (tail);
5459 else
5460 prev = xcdr_addr (tail);
5462 return list;
5465 static void
5466 mark_pinned_symbols (void)
5468 struct symbol_block *sblk;
5469 int lim = (symbol_block_pinned == symbol_block
5470 ? symbol_block_index : SYMBOL_BLOCK_SIZE);
5472 for (sblk = symbol_block_pinned; sblk; sblk = sblk->next)
5474 union aligned_Lisp_Symbol *sym = sblk->symbols, *end = sym + lim;
5475 for (; sym < end; ++sym)
5476 if (sym->s.pinned)
5477 mark_object (make_lisp_ptr (&sym->s, Lisp_Symbol));
5479 lim = SYMBOL_BLOCK_SIZE;
5483 DEFUN ("garbage-collect", Fgarbage_collect, Sgarbage_collect, 0, 0, "",
5484 doc: /* Reclaim storage for Lisp objects no longer needed.
5485 Garbage collection happens automatically if you cons more than
5486 `gc-cons-threshold' bytes of Lisp data since previous garbage collection.
5487 `garbage-collect' normally returns a list with info on amount of space in use,
5488 where each entry has the form (NAME SIZE USED FREE), where:
5489 - NAME is a symbol describing the kind of objects this entry represents,
5490 - SIZE is the number of bytes used by each one,
5491 - USED is the number of those objects that were found live in the heap,
5492 - FREE is the number of those objects that are not live but that Emacs
5493 keeps around for future allocations (maybe because it does not know how
5494 to return them to the OS).
5495 However, if there was overflow in pure space, `garbage-collect'
5496 returns nil, because real GC can't be done.
5497 See Info node `(elisp)Garbage Collection'. */)
5498 (void)
5500 struct buffer *nextb;
5501 char stack_top_variable;
5502 ptrdiff_t i;
5503 bool message_p;
5504 ptrdiff_t count = SPECPDL_INDEX ();
5505 struct timespec start;
5506 Lisp_Object retval = Qnil;
5507 size_t tot_before = 0;
5509 if (abort_on_gc)
5510 emacs_abort ();
5512 /* Can't GC if pure storage overflowed because we can't determine
5513 if something is a pure object or not. */
5514 if (pure_bytes_used_before_overflow)
5515 return Qnil;
5517 /* Record this function, so it appears on the profiler's backtraces. */
5518 record_in_backtrace (Qautomatic_gc, &Qnil, 0);
5520 check_cons_list ();
5522 /* Don't keep undo information around forever.
5523 Do this early on, so it is no problem if the user quits. */
5524 FOR_EACH_BUFFER (nextb)
5525 compact_buffer (nextb);
5527 if (profiler_memory_running)
5528 tot_before = total_bytes_of_live_objects ();
5530 start = current_timespec ();
5532 /* In case user calls debug_print during GC,
5533 don't let that cause a recursive GC. */
5534 consing_since_gc = 0;
5536 /* Save what's currently displayed in the echo area. */
5537 message_p = push_message ();
5538 record_unwind_protect_void (pop_message_unwind);
5540 /* Save a copy of the contents of the stack, for debugging. */
5541 #if MAX_SAVE_STACK > 0
5542 if (NILP (Vpurify_flag))
5544 char *stack;
5545 ptrdiff_t stack_size;
5546 if (&stack_top_variable < stack_bottom)
5548 stack = &stack_top_variable;
5549 stack_size = stack_bottom - &stack_top_variable;
5551 else
5553 stack = stack_bottom;
5554 stack_size = &stack_top_variable - stack_bottom;
5556 if (stack_size <= MAX_SAVE_STACK)
5558 if (stack_copy_size < stack_size)
5560 stack_copy = xrealloc (stack_copy, stack_size);
5561 stack_copy_size = stack_size;
5563 no_sanitize_memcpy (stack_copy, stack, stack_size);
5566 #endif /* MAX_SAVE_STACK > 0 */
5568 if (garbage_collection_messages)
5569 message1_nolog ("Garbage collecting...");
5571 block_input ();
5573 shrink_regexp_cache ();
5575 gc_in_progress = 1;
5577 /* Mark all the special slots that serve as the roots of accessibility. */
5579 mark_buffer (&buffer_defaults);
5580 mark_buffer (&buffer_local_symbols);
5582 for (i = 0; i < staticidx; i++)
5583 mark_object (*staticvec[i]);
5585 mark_pinned_symbols ();
5586 mark_specpdl ();
5587 mark_terminals ();
5588 mark_kboards ();
5590 #ifdef USE_GTK
5591 xg_mark_data ();
5592 #endif
5594 #if (GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS \
5595 || GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS)
5596 mark_stack ();
5597 #else
5599 register struct gcpro *tail;
5600 for (tail = gcprolist; tail; tail = tail->next)
5601 for (i = 0; i < tail->nvars; i++)
5602 mark_object (tail->var[i]);
5604 mark_byte_stack ();
5605 #endif
5607 struct handler *handler;
5608 for (handler = handlerlist; handler; handler = handler->next)
5610 mark_object (handler->tag_or_ch);
5611 mark_object (handler->val);
5614 #ifdef HAVE_WINDOW_SYSTEM
5615 mark_fringe_data ();
5616 #endif
5618 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5619 mark_stack ();
5620 #endif
5622 /* Everything is now marked, except for the data in font caches
5623 and undo lists. They're compacted by removing an items which
5624 aren't reachable otherwise. */
5626 compact_font_caches ();
5628 FOR_EACH_BUFFER (nextb)
5630 if (!EQ (BVAR (nextb, undo_list), Qt))
5631 bset_undo_list (nextb, compact_undo_list (BVAR (nextb, undo_list)));
5632 /* Now that we have stripped the elements that need not be
5633 in the undo_list any more, we can finally mark the list. */
5634 mark_object (BVAR (nextb, undo_list));
5637 gc_sweep ();
5639 /* Clear the mark bits that we set in certain root slots. */
5641 unmark_byte_stack ();
5642 VECTOR_UNMARK (&buffer_defaults);
5643 VECTOR_UNMARK (&buffer_local_symbols);
5645 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES && 0
5646 dump_zombies ();
5647 #endif
5649 check_cons_list ();
5651 gc_in_progress = 0;
5653 unblock_input ();
5655 consing_since_gc = 0;
5656 if (gc_cons_threshold < GC_DEFAULT_THRESHOLD / 10)
5657 gc_cons_threshold = GC_DEFAULT_THRESHOLD / 10;
5659 gc_relative_threshold = 0;
5660 if (FLOATP (Vgc_cons_percentage))
5661 { /* Set gc_cons_combined_threshold. */
5662 double tot = total_bytes_of_live_objects ();
5664 tot *= XFLOAT_DATA (Vgc_cons_percentage);
5665 if (0 < tot)
5667 if (tot < TYPE_MAXIMUM (EMACS_INT))
5668 gc_relative_threshold = tot;
5669 else
5670 gc_relative_threshold = TYPE_MAXIMUM (EMACS_INT);
5674 if (garbage_collection_messages)
5676 if (message_p || minibuf_level > 0)
5677 restore_message ();
5678 else
5679 message1_nolog ("Garbage collecting...done");
5682 unbind_to (count, Qnil);
5684 Lisp_Object total[11];
5685 int total_size = 10;
5687 total[0] = list4 (Qconses, make_number (sizeof (struct Lisp_Cons)),
5688 bounded_number (total_conses),
5689 bounded_number (total_free_conses));
5691 total[1] = list4 (Qsymbols, make_number (sizeof (struct Lisp_Symbol)),
5692 bounded_number (total_symbols),
5693 bounded_number (total_free_symbols));
5695 total[2] = list4 (Qmiscs, make_number (sizeof (union Lisp_Misc)),
5696 bounded_number (total_markers),
5697 bounded_number (total_free_markers));
5699 total[3] = list4 (Qstrings, make_number (sizeof (struct Lisp_String)),
5700 bounded_number (total_strings),
5701 bounded_number (total_free_strings));
5703 total[4] = list3 (Qstring_bytes, make_number (1),
5704 bounded_number (total_string_bytes));
5706 total[5] = list3 (Qvectors,
5707 make_number (header_size + sizeof (Lisp_Object)),
5708 bounded_number (total_vectors));
5710 total[6] = list4 (Qvector_slots, make_number (word_size),
5711 bounded_number (total_vector_slots),
5712 bounded_number (total_free_vector_slots));
5714 total[7] = list4 (Qfloats, make_number (sizeof (struct Lisp_Float)),
5715 bounded_number (total_floats),
5716 bounded_number (total_free_floats));
5718 total[8] = list4 (Qintervals, make_number (sizeof (struct interval)),
5719 bounded_number (total_intervals),
5720 bounded_number (total_free_intervals));
5722 total[9] = list3 (Qbuffers, make_number (sizeof (struct buffer)),
5723 bounded_number (total_buffers));
5725 #ifdef DOUG_LEA_MALLOC
5726 total_size++;
5727 total[10] = list4 (Qheap, make_number (1024),
5728 bounded_number ((mallinfo ().uordblks + 1023) >> 10),
5729 bounded_number ((mallinfo ().fordblks + 1023) >> 10));
5730 #endif
5731 retval = Flist (total_size, total);
5734 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5736 /* Compute average percentage of zombies. */
5737 double nlive
5738 = (total_conses + total_symbols + total_markers + total_strings
5739 + total_vectors + total_floats + total_intervals + total_buffers);
5741 avg_live = (avg_live * ngcs + nlive) / (ngcs + 1);
5742 max_live = max (nlive, max_live);
5743 avg_zombies = (avg_zombies * ngcs + nzombies) / (ngcs + 1);
5744 max_zombies = max (nzombies, max_zombies);
5745 ++ngcs;
5747 #endif
5749 if (!NILP (Vpost_gc_hook))
5751 ptrdiff_t gc_count = inhibit_garbage_collection ();
5752 safe_run_hooks (Qpost_gc_hook);
5753 unbind_to (gc_count, Qnil);
5756 /* Accumulate statistics. */
5757 if (FLOATP (Vgc_elapsed))
5759 struct timespec since_start = timespec_sub (current_timespec (), start);
5760 Vgc_elapsed = make_float (XFLOAT_DATA (Vgc_elapsed)
5761 + timespectod (since_start));
5764 gcs_done++;
5766 /* Collect profiling data. */
5767 if (profiler_memory_running)
5769 size_t swept = 0;
5770 size_t tot_after = total_bytes_of_live_objects ();
5771 if (tot_before > tot_after)
5772 swept = tot_before - tot_after;
5773 malloc_probe (swept);
5776 return retval;
5780 /* Mark Lisp objects in glyph matrix MATRIX. Currently the
5781 only interesting objects referenced from glyphs are strings. */
5783 static void
5784 mark_glyph_matrix (struct glyph_matrix *matrix)
5786 struct glyph_row *row = matrix->rows;
5787 struct glyph_row *end = row + matrix->nrows;
5789 for (; row < end; ++row)
5790 if (row->enabled_p)
5792 int area;
5793 for (area = LEFT_MARGIN_AREA; area < LAST_AREA; ++area)
5795 struct glyph *glyph = row->glyphs[area];
5796 struct glyph *end_glyph = glyph + row->used[area];
5798 for (; glyph < end_glyph; ++glyph)
5799 if (STRINGP (glyph->object)
5800 && !STRING_MARKED_P (XSTRING (glyph->object)))
5801 mark_object (glyph->object);
5806 /* Mark reference to a Lisp_Object.
5807 If the object referred to has not been seen yet, recursively mark
5808 all the references contained in it. */
5810 #define LAST_MARKED_SIZE 500
5811 static Lisp_Object last_marked[LAST_MARKED_SIZE];
5812 static int last_marked_index;
5814 /* For debugging--call abort when we cdr down this many
5815 links of a list, in mark_object. In debugging,
5816 the call to abort will hit a breakpoint.
5817 Normally this is zero and the check never goes off. */
5818 ptrdiff_t mark_object_loop_halt EXTERNALLY_VISIBLE;
5820 static void
5821 mark_vectorlike (struct Lisp_Vector *ptr)
5823 ptrdiff_t size = ptr->header.size;
5824 ptrdiff_t i;
5826 eassert (!VECTOR_MARKED_P (ptr));
5827 VECTOR_MARK (ptr); /* Else mark it. */
5828 if (size & PSEUDOVECTOR_FLAG)
5829 size &= PSEUDOVECTOR_SIZE_MASK;
5831 /* Note that this size is not the memory-footprint size, but only
5832 the number of Lisp_Object fields that we should trace.
5833 The distinction is used e.g. by Lisp_Process which places extra
5834 non-Lisp_Object fields at the end of the structure... */
5835 for (i = 0; i < size; i++) /* ...and then mark its elements. */
5836 mark_object (ptr->contents[i]);
5839 /* Like mark_vectorlike but optimized for char-tables (and
5840 sub-char-tables) assuming that the contents are mostly integers or
5841 symbols. */
5843 static void
5844 mark_char_table (struct Lisp_Vector *ptr)
5846 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
5847 int i;
5849 eassert (!VECTOR_MARKED_P (ptr));
5850 VECTOR_MARK (ptr);
5851 for (i = 0; i < size; i++)
5853 Lisp_Object val = ptr->contents[i];
5855 if (INTEGERP (val) || (SYMBOLP (val) && XSYMBOL (val)->gcmarkbit))
5856 continue;
5857 if (SUB_CHAR_TABLE_P (val))
5859 if (! VECTOR_MARKED_P (XVECTOR (val)))
5860 mark_char_table (XVECTOR (val));
5862 else
5863 mark_object (val);
5867 /* Mark the chain of overlays starting at PTR. */
5869 static void
5870 mark_overlay (struct Lisp_Overlay *ptr)
5872 for (; ptr && !ptr->gcmarkbit; ptr = ptr->next)
5874 ptr->gcmarkbit = 1;
5875 mark_object (ptr->start);
5876 mark_object (ptr->end);
5877 mark_object (ptr->plist);
5881 /* Mark Lisp_Objects and special pointers in BUFFER. */
5883 static void
5884 mark_buffer (struct buffer *buffer)
5886 /* This is handled much like other pseudovectors... */
5887 mark_vectorlike ((struct Lisp_Vector *) buffer);
5889 /* ...but there are some buffer-specific things. */
5891 MARK_INTERVAL_TREE (buffer_intervals (buffer));
5893 /* For now, we just don't mark the undo_list. It's done later in
5894 a special way just before the sweep phase, and after stripping
5895 some of its elements that are not needed any more. */
5897 mark_overlay (buffer->overlays_before);
5898 mark_overlay (buffer->overlays_after);
5900 /* If this is an indirect buffer, mark its base buffer. */
5901 if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))
5902 mark_buffer (buffer->base_buffer);
5905 /* Mark Lisp faces in the face cache C. */
5907 static void
5908 mark_face_cache (struct face_cache *c)
5910 if (c)
5912 int i, j;
5913 for (i = 0; i < c->used; ++i)
5915 struct face *face = FACE_FROM_ID (c->f, i);
5917 if (face)
5919 if (face->font && !VECTOR_MARKED_P (face->font))
5920 mark_vectorlike ((struct Lisp_Vector *) face->font);
5922 for (j = 0; j < LFACE_VECTOR_SIZE; ++j)
5923 mark_object (face->lface[j]);
5929 /* Remove killed buffers or items whose car is a killed buffer from
5930 LIST, and mark other items. Return changed LIST, which is marked. */
5932 static Lisp_Object
5933 mark_discard_killed_buffers (Lisp_Object list)
5935 Lisp_Object tail, *prev = &list;
5937 for (tail = list; CONSP (tail) && !CONS_MARKED_P (XCONS (tail));
5938 tail = XCDR (tail))
5940 Lisp_Object tem = XCAR (tail);
5941 if (CONSP (tem))
5942 tem = XCAR (tem);
5943 if (BUFFERP (tem) && !BUFFER_LIVE_P (XBUFFER (tem)))
5944 *prev = XCDR (tail);
5945 else
5947 CONS_MARK (XCONS (tail));
5948 mark_object (XCAR (tail));
5949 prev = xcdr_addr (tail);
5952 mark_object (tail);
5953 return list;
5956 /* Determine type of generic Lisp_Object and mark it accordingly. */
5958 void
5959 mark_object (Lisp_Object arg)
5961 register Lisp_Object obj = arg;
5962 #ifdef GC_CHECK_MARKED_OBJECTS
5963 void *po;
5964 struct mem_node *m;
5965 #endif
5966 ptrdiff_t cdr_count = 0;
5968 loop:
5970 if (PURE_POINTER_P (XPNTR (obj)))
5971 return;
5973 last_marked[last_marked_index++] = obj;
5974 if (last_marked_index == LAST_MARKED_SIZE)
5975 last_marked_index = 0;
5977 /* Perform some sanity checks on the objects marked here. Abort if
5978 we encounter an object we know is bogus. This increases GC time
5979 by ~80%, and requires compilation with GC_MARK_STACK != 0. */
5980 #ifdef GC_CHECK_MARKED_OBJECTS
5982 po = (void *) XPNTR (obj);
5984 /* Check that the object pointed to by PO is known to be a Lisp
5985 structure allocated from the heap. */
5986 #define CHECK_ALLOCATED() \
5987 do { \
5988 m = mem_find (po); \
5989 if (m == MEM_NIL) \
5990 emacs_abort (); \
5991 } while (0)
5993 /* Check that the object pointed to by PO is live, using predicate
5994 function LIVEP. */
5995 #define CHECK_LIVE(LIVEP) \
5996 do { \
5997 if (!LIVEP (m, po)) \
5998 emacs_abort (); \
5999 } while (0)
6001 /* Check both of the above conditions. */
6002 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) \
6003 do { \
6004 CHECK_ALLOCATED (); \
6005 CHECK_LIVE (LIVEP); \
6006 } while (0) \
6008 #else /* not GC_CHECK_MARKED_OBJECTS */
6010 #define CHECK_LIVE(LIVEP) (void) 0
6011 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) (void) 0
6013 #endif /* not GC_CHECK_MARKED_OBJECTS */
6015 switch (XTYPE (obj))
6017 case Lisp_String:
6019 register struct Lisp_String *ptr = XSTRING (obj);
6020 if (STRING_MARKED_P (ptr))
6021 break;
6022 CHECK_ALLOCATED_AND_LIVE (live_string_p);
6023 MARK_STRING (ptr);
6024 MARK_INTERVAL_TREE (ptr->intervals);
6025 #ifdef GC_CHECK_STRING_BYTES
6026 /* Check that the string size recorded in the string is the
6027 same as the one recorded in the sdata structure. */
6028 string_bytes (ptr);
6029 #endif /* GC_CHECK_STRING_BYTES */
6031 break;
6033 case Lisp_Vectorlike:
6035 register struct Lisp_Vector *ptr = XVECTOR (obj);
6036 register ptrdiff_t pvectype;
6038 if (VECTOR_MARKED_P (ptr))
6039 break;
6041 #ifdef GC_CHECK_MARKED_OBJECTS
6042 m = mem_find (po);
6043 if (m == MEM_NIL && !SUBRP (obj))
6044 emacs_abort ();
6045 #endif /* GC_CHECK_MARKED_OBJECTS */
6047 if (ptr->header.size & PSEUDOVECTOR_FLAG)
6048 pvectype = ((ptr->header.size & PVEC_TYPE_MASK)
6049 >> PSEUDOVECTOR_AREA_BITS);
6050 else
6051 pvectype = PVEC_NORMAL_VECTOR;
6053 if (pvectype != PVEC_SUBR && pvectype != PVEC_BUFFER)
6054 CHECK_LIVE (live_vector_p);
6056 switch (pvectype)
6058 case PVEC_BUFFER:
6059 #ifdef GC_CHECK_MARKED_OBJECTS
6061 struct buffer *b;
6062 FOR_EACH_BUFFER (b)
6063 if (b == po)
6064 break;
6065 if (b == NULL)
6066 emacs_abort ();
6068 #endif /* GC_CHECK_MARKED_OBJECTS */
6069 mark_buffer ((struct buffer *) ptr);
6070 break;
6072 case PVEC_COMPILED:
6073 { /* We could treat this just like a vector, but it is better
6074 to save the COMPILED_CONSTANTS element for last and avoid
6075 recursion there. */
6076 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
6077 int i;
6079 VECTOR_MARK (ptr);
6080 for (i = 0; i < size; i++)
6081 if (i != COMPILED_CONSTANTS)
6082 mark_object (ptr->contents[i]);
6083 if (size > COMPILED_CONSTANTS)
6085 obj = ptr->contents[COMPILED_CONSTANTS];
6086 goto loop;
6089 break;
6091 case PVEC_FRAME:
6093 struct frame *f = (struct frame *) ptr;
6095 mark_vectorlike (ptr);
6096 mark_face_cache (f->face_cache);
6097 #ifdef HAVE_WINDOW_SYSTEM
6098 if (FRAME_WINDOW_P (f) && FRAME_X_OUTPUT (f))
6100 struct font *font = FRAME_FONT (f);
6102 if (font && !VECTOR_MARKED_P (font))
6103 mark_vectorlike ((struct Lisp_Vector *) font);
6105 #endif
6107 break;
6109 case PVEC_WINDOW:
6111 struct window *w = (struct window *) ptr;
6113 mark_vectorlike (ptr);
6115 /* Mark glyph matrices, if any. Marking window
6116 matrices is sufficient because frame matrices
6117 use the same glyph memory. */
6118 if (w->current_matrix)
6120 mark_glyph_matrix (w->current_matrix);
6121 mark_glyph_matrix (w->desired_matrix);
6124 /* Filter out killed buffers from both buffer lists
6125 in attempt to help GC to reclaim killed buffers faster.
6126 We can do it elsewhere for live windows, but this is the
6127 best place to do it for dead windows. */
6128 wset_prev_buffers
6129 (w, mark_discard_killed_buffers (w->prev_buffers));
6130 wset_next_buffers
6131 (w, mark_discard_killed_buffers (w->next_buffers));
6133 break;
6135 case PVEC_HASH_TABLE:
6137 struct Lisp_Hash_Table *h = (struct Lisp_Hash_Table *) ptr;
6139 mark_vectorlike (ptr);
6140 mark_object (h->test.name);
6141 mark_object (h->test.user_hash_function);
6142 mark_object (h->test.user_cmp_function);
6143 /* If hash table is not weak, mark all keys and values.
6144 For weak tables, mark only the vector. */
6145 if (NILP (h->weak))
6146 mark_object (h->key_and_value);
6147 else
6148 VECTOR_MARK (XVECTOR (h->key_and_value));
6150 break;
6152 case PVEC_CHAR_TABLE:
6153 mark_char_table (ptr);
6154 break;
6156 case PVEC_BOOL_VECTOR:
6157 /* No Lisp_Objects to mark in a bool vector. */
6158 VECTOR_MARK (ptr);
6159 break;
6161 case PVEC_SUBR:
6162 break;
6164 case PVEC_FREE:
6165 emacs_abort ();
6167 default:
6168 mark_vectorlike (ptr);
6171 break;
6173 case Lisp_Symbol:
6175 register struct Lisp_Symbol *ptr = XSYMBOL (obj);
6176 struct Lisp_Symbol *ptrx;
6178 if (ptr->gcmarkbit)
6179 break;
6180 CHECK_ALLOCATED_AND_LIVE (live_symbol_p);
6181 ptr->gcmarkbit = 1;
6182 mark_object (ptr->function);
6183 mark_object (ptr->plist);
6184 switch (ptr->redirect)
6186 case SYMBOL_PLAINVAL: mark_object (SYMBOL_VAL (ptr)); break;
6187 case SYMBOL_VARALIAS:
6189 Lisp_Object tem;
6190 XSETSYMBOL (tem, SYMBOL_ALIAS (ptr));
6191 mark_object (tem);
6192 break;
6194 case SYMBOL_LOCALIZED:
6196 struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr);
6197 Lisp_Object where = blv->where;
6198 /* If the value is set up for a killed buffer or deleted
6199 frame, restore it's global binding. If the value is
6200 forwarded to a C variable, either it's not a Lisp_Object
6201 var, or it's staticpro'd already. */
6202 if ((BUFFERP (where) && !BUFFER_LIVE_P (XBUFFER (where)))
6203 || (FRAMEP (where) && !FRAME_LIVE_P (XFRAME (where))))
6204 swap_in_global_binding (ptr);
6205 mark_object (blv->where);
6206 mark_object (blv->valcell);
6207 mark_object (blv->defcell);
6208 break;
6210 case SYMBOL_FORWARDED:
6211 /* If the value is forwarded to a buffer or keyboard field,
6212 these are marked when we see the corresponding object.
6213 And if it's forwarded to a C variable, either it's not
6214 a Lisp_Object var, or it's staticpro'd already. */
6215 break;
6216 default: emacs_abort ();
6218 if (!PURE_POINTER_P (XSTRING (ptr->name)))
6219 MARK_STRING (XSTRING (ptr->name));
6220 MARK_INTERVAL_TREE (string_intervals (ptr->name));
6222 ptr = ptr->next;
6223 if (ptr)
6225 ptrx = ptr; /* Use of ptrx avoids compiler bug on Sun. */
6226 XSETSYMBOL (obj, ptrx);
6227 goto loop;
6230 break;
6232 case Lisp_Misc:
6233 CHECK_ALLOCATED_AND_LIVE (live_misc_p);
6235 if (XMISCANY (obj)->gcmarkbit)
6236 break;
6238 switch (XMISCTYPE (obj))
6240 case Lisp_Misc_Marker:
6241 /* DO NOT mark thru the marker's chain.
6242 The buffer's markers chain does not preserve markers from gc;
6243 instead, markers are removed from the chain when freed by gc. */
6244 XMISCANY (obj)->gcmarkbit = 1;
6245 break;
6247 case Lisp_Misc_Save_Value:
6248 XMISCANY (obj)->gcmarkbit = 1;
6250 struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
6251 /* If `save_type' is zero, `data[0].pointer' is the address
6252 of a memory area containing `data[1].integer' potential
6253 Lisp_Objects. */
6254 if (GC_MARK_STACK && ptr->save_type == SAVE_TYPE_MEMORY)
6256 Lisp_Object *p = ptr->data[0].pointer;
6257 ptrdiff_t nelt;
6258 for (nelt = ptr->data[1].integer; nelt > 0; nelt--, p++)
6259 mark_maybe_object (*p);
6261 else
6263 /* Find Lisp_Objects in `data[N]' slots and mark them. */
6264 int i;
6265 for (i = 0; i < SAVE_VALUE_SLOTS; i++)
6266 if (save_type (ptr, i) == SAVE_OBJECT)
6267 mark_object (ptr->data[i].object);
6270 break;
6272 case Lisp_Misc_Overlay:
6273 mark_overlay (XOVERLAY (obj));
6274 break;
6276 default:
6277 emacs_abort ();
6279 break;
6281 case Lisp_Cons:
6283 register struct Lisp_Cons *ptr = XCONS (obj);
6284 if (CONS_MARKED_P (ptr))
6285 break;
6286 CHECK_ALLOCATED_AND_LIVE (live_cons_p);
6287 CONS_MARK (ptr);
6288 /* If the cdr is nil, avoid recursion for the car. */
6289 if (EQ (ptr->u.cdr, Qnil))
6291 obj = ptr->car;
6292 cdr_count = 0;
6293 goto loop;
6295 mark_object (ptr->car);
6296 obj = ptr->u.cdr;
6297 cdr_count++;
6298 if (cdr_count == mark_object_loop_halt)
6299 emacs_abort ();
6300 goto loop;
6303 case Lisp_Float:
6304 CHECK_ALLOCATED_AND_LIVE (live_float_p);
6305 FLOAT_MARK (XFLOAT (obj));
6306 break;
6308 case_Lisp_Int:
6309 break;
6311 default:
6312 emacs_abort ();
6315 #undef CHECK_LIVE
6316 #undef CHECK_ALLOCATED
6317 #undef CHECK_ALLOCATED_AND_LIVE
6319 /* Mark the Lisp pointers in the terminal objects.
6320 Called by Fgarbage_collect. */
6322 static void
6323 mark_terminals (void)
6325 struct terminal *t;
6326 for (t = terminal_list; t; t = t->next_terminal)
6328 eassert (t->name != NULL);
6329 #ifdef HAVE_WINDOW_SYSTEM
6330 /* If a terminal object is reachable from a stacpro'ed object,
6331 it might have been marked already. Make sure the image cache
6332 gets marked. */
6333 mark_image_cache (t->image_cache);
6334 #endif /* HAVE_WINDOW_SYSTEM */
6335 if (!VECTOR_MARKED_P (t))
6336 mark_vectorlike ((struct Lisp_Vector *)t);
6342 /* Value is non-zero if OBJ will survive the current GC because it's
6343 either marked or does not need to be marked to survive. */
6345 bool
6346 survives_gc_p (Lisp_Object obj)
6348 bool survives_p;
6350 switch (XTYPE (obj))
6352 case_Lisp_Int:
6353 survives_p = 1;
6354 break;
6356 case Lisp_Symbol:
6357 survives_p = XSYMBOL (obj)->gcmarkbit;
6358 break;
6360 case Lisp_Misc:
6361 survives_p = XMISCANY (obj)->gcmarkbit;
6362 break;
6364 case Lisp_String:
6365 survives_p = STRING_MARKED_P (XSTRING (obj));
6366 break;
6368 case Lisp_Vectorlike:
6369 survives_p = SUBRP (obj) || VECTOR_MARKED_P (XVECTOR (obj));
6370 break;
6372 case Lisp_Cons:
6373 survives_p = CONS_MARKED_P (XCONS (obj));
6374 break;
6376 case Lisp_Float:
6377 survives_p = FLOAT_MARKED_P (XFLOAT (obj));
6378 break;
6380 default:
6381 emacs_abort ();
6384 return survives_p || PURE_POINTER_P ((void *) XPNTR (obj));
6389 /* Sweep: find all structures not marked, and free them. */
6391 static void
6392 gc_sweep (void)
6394 /* Remove or mark entries in weak hash tables.
6395 This must be done before any object is unmarked. */
6396 sweep_weak_hash_tables ();
6398 sweep_strings ();
6399 check_string_bytes (!noninteractive);
6401 /* Put all unmarked conses on free list. */
6403 register struct cons_block *cblk;
6404 struct cons_block **cprev = &cons_block;
6405 register int lim = cons_block_index;
6406 EMACS_INT num_free = 0, num_used = 0;
6408 cons_free_list = 0;
6410 for (cblk = cons_block; cblk; cblk = *cprev)
6412 register int i = 0;
6413 int this_free = 0;
6414 int ilim = (lim + BITS_PER_INT - 1) / BITS_PER_INT;
6416 /* Scan the mark bits an int at a time. */
6417 for (i = 0; i < ilim; i++)
6419 if (cblk->gcmarkbits[i] == -1)
6421 /* Fast path - all cons cells for this int are marked. */
6422 cblk->gcmarkbits[i] = 0;
6423 num_used += BITS_PER_INT;
6425 else
6427 /* Some cons cells for this int are not marked.
6428 Find which ones, and free them. */
6429 int start, pos, stop;
6431 start = i * BITS_PER_INT;
6432 stop = lim - start;
6433 if (stop > BITS_PER_INT)
6434 stop = BITS_PER_INT;
6435 stop += start;
6437 for (pos = start; pos < stop; pos++)
6439 if (!CONS_MARKED_P (&cblk->conses[pos]))
6441 this_free++;
6442 cblk->conses[pos].u.chain = cons_free_list;
6443 cons_free_list = &cblk->conses[pos];
6444 #if GC_MARK_STACK
6445 cons_free_list->car = Vdead;
6446 #endif
6448 else
6450 num_used++;
6451 CONS_UNMARK (&cblk->conses[pos]);
6457 lim = CONS_BLOCK_SIZE;
6458 /* If this block contains only free conses and we have already
6459 seen more than two blocks worth of free conses then deallocate
6460 this block. */
6461 if (this_free == CONS_BLOCK_SIZE && num_free > CONS_BLOCK_SIZE)
6463 *cprev = cblk->next;
6464 /* Unhook from the free list. */
6465 cons_free_list = cblk->conses[0].u.chain;
6466 lisp_align_free (cblk);
6468 else
6470 num_free += this_free;
6471 cprev = &cblk->next;
6474 total_conses = num_used;
6475 total_free_conses = num_free;
6478 /* Put all unmarked floats on free list. */
6480 register struct float_block *fblk;
6481 struct float_block **fprev = &float_block;
6482 register int lim = float_block_index;
6483 EMACS_INT num_free = 0, num_used = 0;
6485 float_free_list = 0;
6487 for (fblk = float_block; fblk; fblk = *fprev)
6489 register int i;
6490 int this_free = 0;
6491 for (i = 0; i < lim; i++)
6492 if (!FLOAT_MARKED_P (&fblk->floats[i]))
6494 this_free++;
6495 fblk->floats[i].u.chain = float_free_list;
6496 float_free_list = &fblk->floats[i];
6498 else
6500 num_used++;
6501 FLOAT_UNMARK (&fblk->floats[i]);
6503 lim = FLOAT_BLOCK_SIZE;
6504 /* If this block contains only free floats and we have already
6505 seen more than two blocks worth of free floats then deallocate
6506 this block. */
6507 if (this_free == FLOAT_BLOCK_SIZE && num_free > FLOAT_BLOCK_SIZE)
6509 *fprev = fblk->next;
6510 /* Unhook from the free list. */
6511 float_free_list = fblk->floats[0].u.chain;
6512 lisp_align_free (fblk);
6514 else
6516 num_free += this_free;
6517 fprev = &fblk->next;
6520 total_floats = num_used;
6521 total_free_floats = num_free;
6524 /* Put all unmarked intervals on free list. */
6526 register struct interval_block *iblk;
6527 struct interval_block **iprev = &interval_block;
6528 register int lim = interval_block_index;
6529 EMACS_INT num_free = 0, num_used = 0;
6531 interval_free_list = 0;
6533 for (iblk = interval_block; iblk; iblk = *iprev)
6535 register int i;
6536 int this_free = 0;
6538 for (i = 0; i < lim; i++)
6540 if (!iblk->intervals[i].gcmarkbit)
6542 set_interval_parent (&iblk->intervals[i], interval_free_list);
6543 interval_free_list = &iblk->intervals[i];
6544 this_free++;
6546 else
6548 num_used++;
6549 iblk->intervals[i].gcmarkbit = 0;
6552 lim = INTERVAL_BLOCK_SIZE;
6553 /* If this block contains only free intervals and we have already
6554 seen more than two blocks worth of free intervals then
6555 deallocate this block. */
6556 if (this_free == INTERVAL_BLOCK_SIZE && num_free > INTERVAL_BLOCK_SIZE)
6558 *iprev = iblk->next;
6559 /* Unhook from the free list. */
6560 interval_free_list = INTERVAL_PARENT (&iblk->intervals[0]);
6561 lisp_free (iblk);
6563 else
6565 num_free += this_free;
6566 iprev = &iblk->next;
6569 total_intervals = num_used;
6570 total_free_intervals = num_free;
6573 /* Put all unmarked symbols on free list. */
6575 register struct symbol_block *sblk;
6576 struct symbol_block **sprev = &symbol_block;
6577 register int lim = symbol_block_index;
6578 EMACS_INT num_free = 0, num_used = 0;
6580 symbol_free_list = NULL;
6582 for (sblk = symbol_block; sblk; sblk = *sprev)
6584 int this_free = 0;
6585 union aligned_Lisp_Symbol *sym = sblk->symbols;
6586 union aligned_Lisp_Symbol *end = sym + lim;
6588 for (; sym < end; ++sym)
6590 if (!sym->s.gcmarkbit)
6592 if (sym->s.redirect == SYMBOL_LOCALIZED)
6593 xfree (SYMBOL_BLV (&sym->s));
6594 sym->s.next = symbol_free_list;
6595 symbol_free_list = &sym->s;
6596 #if GC_MARK_STACK
6597 symbol_free_list->function = Vdead;
6598 #endif
6599 ++this_free;
6601 else
6603 ++num_used;
6604 eassert (!STRING_MARKED_P (XSTRING (sym->s.name)));
6605 sym->s.gcmarkbit = 0;
6609 lim = SYMBOL_BLOCK_SIZE;
6610 /* If this block contains only free symbols and we have already
6611 seen more than two blocks worth of free symbols then deallocate
6612 this block. */
6613 if (this_free == SYMBOL_BLOCK_SIZE && num_free > SYMBOL_BLOCK_SIZE)
6615 *sprev = sblk->next;
6616 /* Unhook from the free list. */
6617 symbol_free_list = sblk->symbols[0].s.next;
6618 lisp_free (sblk);
6620 else
6622 num_free += this_free;
6623 sprev = &sblk->next;
6626 total_symbols = num_used;
6627 total_free_symbols = num_free;
6630 /* Put all unmarked misc's on free list.
6631 For a marker, first unchain it from the buffer it points into. */
6633 register struct marker_block *mblk;
6634 struct marker_block **mprev = &marker_block;
6635 register int lim = marker_block_index;
6636 EMACS_INT num_free = 0, num_used = 0;
6638 marker_free_list = 0;
6640 for (mblk = marker_block; mblk; mblk = *mprev)
6642 register int i;
6643 int this_free = 0;
6645 for (i = 0; i < lim; i++)
6647 if (!mblk->markers[i].m.u_any.gcmarkbit)
6649 if (mblk->markers[i].m.u_any.type == Lisp_Misc_Marker)
6650 unchain_marker (&mblk->markers[i].m.u_marker);
6651 /* Set the type of the freed object to Lisp_Misc_Free.
6652 We could leave the type alone, since nobody checks it,
6653 but this might catch bugs faster. */
6654 mblk->markers[i].m.u_marker.type = Lisp_Misc_Free;
6655 mblk->markers[i].m.u_free.chain = marker_free_list;
6656 marker_free_list = &mblk->markers[i].m;
6657 this_free++;
6659 else
6661 num_used++;
6662 mblk->markers[i].m.u_any.gcmarkbit = 0;
6665 lim = MARKER_BLOCK_SIZE;
6666 /* If this block contains only free markers and we have already
6667 seen more than two blocks worth of free markers then deallocate
6668 this block. */
6669 if (this_free == MARKER_BLOCK_SIZE && num_free > MARKER_BLOCK_SIZE)
6671 *mprev = mblk->next;
6672 /* Unhook from the free list. */
6673 marker_free_list = mblk->markers[0].m.u_free.chain;
6674 lisp_free (mblk);
6676 else
6678 num_free += this_free;
6679 mprev = &mblk->next;
6683 total_markers = num_used;
6684 total_free_markers = num_free;
6687 /* Free all unmarked buffers */
6689 register struct buffer *buffer, **bprev = &all_buffers;
6691 total_buffers = 0;
6692 for (buffer = all_buffers; buffer; buffer = *bprev)
6693 if (!VECTOR_MARKED_P (buffer))
6695 *bprev = buffer->next;
6696 lisp_free (buffer);
6698 else
6700 VECTOR_UNMARK (buffer);
6701 /* Do not use buffer_(set|get)_intervals here. */
6702 buffer->text->intervals = balance_intervals (buffer->text->intervals);
6703 total_buffers++;
6704 bprev = &buffer->next;
6708 sweep_vectors ();
6709 check_string_bytes (!noninteractive);
6715 /* Debugging aids. */
6717 DEFUN ("memory-limit", Fmemory_limit, Smemory_limit, 0, 0, 0,
6718 doc: /* Return the address of the last byte Emacs has allocated, divided by 1024.
6719 This may be helpful in debugging Emacs's memory usage.
6720 We divide the value by 1024 to make sure it fits in a Lisp integer. */)
6721 (void)
6723 Lisp_Object end;
6725 #ifdef HAVE_NS
6726 /* Avoid warning. sbrk has no relation to memory allocated anyway. */
6727 XSETINT (end, 0);
6728 #else
6729 XSETINT (end, (intptr_t) (char *) sbrk (0) / 1024);
6730 #endif
6732 return end;
6735 DEFUN ("memory-use-counts", Fmemory_use_counts, Smemory_use_counts, 0, 0, 0,
6736 doc: /* Return a list of counters that measure how much consing there has been.
6737 Each of these counters increments for a certain kind of object.
6738 The counters wrap around from the largest positive integer to zero.
6739 Garbage collection does not decrease them.
6740 The elements of the value are as follows:
6741 (CONSES FLOATS VECTOR-CELLS SYMBOLS STRING-CHARS MISCS INTERVALS STRINGS)
6742 All are in units of 1 = one object consed
6743 except for VECTOR-CELLS and STRING-CHARS, which count the total length of
6744 objects consed.
6745 MISCS include overlays, markers, and some internal types.
6746 Frames, windows, buffers, and subprocesses count as vectors
6747 (but the contents of a buffer's text do not count here). */)
6748 (void)
6750 return listn (CONSTYPE_HEAP, 8,
6751 bounded_number (cons_cells_consed),
6752 bounded_number (floats_consed),
6753 bounded_number (vector_cells_consed),
6754 bounded_number (symbols_consed),
6755 bounded_number (string_chars_consed),
6756 bounded_number (misc_objects_consed),
6757 bounded_number (intervals_consed),
6758 bounded_number (strings_consed));
6761 /* Find at most FIND_MAX symbols which have OBJ as their value or
6762 function. This is used in gdbinit's `xwhichsymbols' command. */
6764 Lisp_Object
6765 which_symbols (Lisp_Object obj, EMACS_INT find_max)
6767 struct symbol_block *sblk;
6768 ptrdiff_t gc_count = inhibit_garbage_collection ();
6769 Lisp_Object found = Qnil;
6771 if (! DEADP (obj))
6773 for (sblk = symbol_block; sblk; sblk = sblk->next)
6775 union aligned_Lisp_Symbol *aligned_sym = sblk->symbols;
6776 int bn;
6778 for (bn = 0; bn < SYMBOL_BLOCK_SIZE; bn++, aligned_sym++)
6780 struct Lisp_Symbol *sym = &aligned_sym->s;
6781 Lisp_Object val;
6782 Lisp_Object tem;
6784 if (sblk == symbol_block && bn >= symbol_block_index)
6785 break;
6787 XSETSYMBOL (tem, sym);
6788 val = find_symbol_value (tem);
6789 if (EQ (val, obj)
6790 || EQ (sym->function, obj)
6791 || (!NILP (sym->function)
6792 && COMPILEDP (sym->function)
6793 && EQ (AREF (sym->function, COMPILED_BYTECODE), obj))
6794 || (!NILP (val)
6795 && COMPILEDP (val)
6796 && EQ (AREF (val, COMPILED_BYTECODE), obj)))
6798 found = Fcons (tem, found);
6799 if (--find_max == 0)
6800 goto out;
6806 out:
6807 unbind_to (gc_count, Qnil);
6808 return found;
6811 #ifdef ENABLE_CHECKING
6813 bool suppress_checking;
6815 void
6816 die (const char *msg, const char *file, int line)
6818 fprintf (stderr, "\r\n%s:%d: Emacs fatal error: assertion failed: %s\r\n",
6819 file, line, msg);
6820 terminate_due_to_signal (SIGABRT, INT_MAX);
6822 #endif
6824 /* Initialization. */
6826 void
6827 init_alloc_once (void)
6829 /* Used to do Vpurify_flag = Qt here, but Qt isn't set up yet! */
6830 purebeg = PUREBEG;
6831 pure_size = PURESIZE;
6833 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
6834 mem_init ();
6835 Vdead = make_pure_string ("DEAD", 4, 4, 0);
6836 #endif
6838 #ifdef DOUG_LEA_MALLOC
6839 mallopt (M_TRIM_THRESHOLD, 128 * 1024); /* Trim threshold. */
6840 mallopt (M_MMAP_THRESHOLD, 64 * 1024); /* Mmap threshold. */
6841 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS); /* Max. number of mmap'ed areas. */
6842 #endif
6843 init_strings ();
6844 init_vectors ();
6846 refill_memory_reserve ();
6847 gc_cons_threshold = GC_DEFAULT_THRESHOLD;
6850 void
6851 init_alloc (void)
6853 gcprolist = 0;
6854 byte_stack_list = 0;
6855 #if GC_MARK_STACK
6856 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
6857 setjmp_tested_p = longjmps_done = 0;
6858 #endif
6859 #endif
6860 Vgc_elapsed = make_float (0.0);
6861 gcs_done = 0;
6863 #if USE_VALGRIND
6864 valgrind_p = RUNNING_ON_VALGRIND != 0;
6865 #endif
6868 void
6869 syms_of_alloc (void)
6871 DEFVAR_INT ("gc-cons-threshold", gc_cons_threshold,
6872 doc: /* Number of bytes of consing between garbage collections.
6873 Garbage collection can happen automatically once this many bytes have been
6874 allocated since the last garbage collection. All data types count.
6876 Garbage collection happens automatically only when `eval' is called.
6878 By binding this temporarily to a large number, you can effectively
6879 prevent garbage collection during a part of the program.
6880 See also `gc-cons-percentage'. */);
6882 DEFVAR_LISP ("gc-cons-percentage", Vgc_cons_percentage,
6883 doc: /* Portion of the heap used for allocation.
6884 Garbage collection can happen automatically once this portion of the heap
6885 has been allocated since the last garbage collection.
6886 If this portion is smaller than `gc-cons-threshold', this is ignored. */);
6887 Vgc_cons_percentage = make_float (0.1);
6889 DEFVAR_INT ("pure-bytes-used", pure_bytes_used,
6890 doc: /* Number of bytes of shareable Lisp data allocated so far. */);
6892 DEFVAR_INT ("cons-cells-consed", cons_cells_consed,
6893 doc: /* Number of cons cells that have been consed so far. */);
6895 DEFVAR_INT ("floats-consed", floats_consed,
6896 doc: /* Number of floats that have been consed so far. */);
6898 DEFVAR_INT ("vector-cells-consed", vector_cells_consed,
6899 doc: /* Number of vector cells that have been consed so far. */);
6901 DEFVAR_INT ("symbols-consed", symbols_consed,
6902 doc: /* Number of symbols that have been consed so far. */);
6904 DEFVAR_INT ("string-chars-consed", string_chars_consed,
6905 doc: /* Number of string characters that have been consed so far. */);
6907 DEFVAR_INT ("misc-objects-consed", misc_objects_consed,
6908 doc: /* Number of miscellaneous objects that have been consed so far.
6909 These include markers and overlays, plus certain objects not visible
6910 to users. */);
6912 DEFVAR_INT ("intervals-consed", intervals_consed,
6913 doc: /* Number of intervals that have been consed so far. */);
6915 DEFVAR_INT ("strings-consed", strings_consed,
6916 doc: /* Number of strings that have been consed so far. */);
6918 DEFVAR_LISP ("purify-flag", Vpurify_flag,
6919 doc: /* Non-nil means loading Lisp code in order to dump an executable.
6920 This means that certain objects should be allocated in shared (pure) space.
6921 It can also be set to a hash-table, in which case this table is used to
6922 do hash-consing of the objects allocated to pure space. */);
6924 DEFVAR_BOOL ("garbage-collection-messages", garbage_collection_messages,
6925 doc: /* Non-nil means display messages at start and end of garbage collection. */);
6926 garbage_collection_messages = 0;
6928 DEFVAR_LISP ("post-gc-hook", Vpost_gc_hook,
6929 doc: /* Hook run after garbage collection has finished. */);
6930 Vpost_gc_hook = Qnil;
6931 DEFSYM (Qpost_gc_hook, "post-gc-hook");
6933 DEFVAR_LISP ("memory-signal-data", Vmemory_signal_data,
6934 doc: /* Precomputed `signal' argument for memory-full error. */);
6935 /* We build this in advance because if we wait until we need it, we might
6936 not be able to allocate the memory to hold it. */
6937 Vmemory_signal_data
6938 = listn (CONSTYPE_PURE, 2, Qerror,
6939 build_pure_c_string ("Memory exhausted--use M-x save-some-buffers then exit and restart Emacs"));
6941 DEFVAR_LISP ("memory-full", Vmemory_full,
6942 doc: /* Non-nil means Emacs cannot get much more Lisp memory. */);
6943 Vmemory_full = Qnil;
6945 DEFSYM (Qconses, "conses");
6946 DEFSYM (Qsymbols, "symbols");
6947 DEFSYM (Qmiscs, "miscs");
6948 DEFSYM (Qstrings, "strings");
6949 DEFSYM (Qvectors, "vectors");
6950 DEFSYM (Qfloats, "floats");
6951 DEFSYM (Qintervals, "intervals");
6952 DEFSYM (Qbuffers, "buffers");
6953 DEFSYM (Qstring_bytes, "string-bytes");
6954 DEFSYM (Qvector_slots, "vector-slots");
6955 DEFSYM (Qheap, "heap");
6956 DEFSYM (Qautomatic_gc, "Automatic GC");
6958 DEFSYM (Qgc_cons_threshold, "gc-cons-threshold");
6959 DEFSYM (Qchar_table_extra_slots, "char-table-extra-slots");
6961 DEFVAR_LISP ("gc-elapsed", Vgc_elapsed,
6962 doc: /* Accumulated time elapsed in garbage collections.
6963 The time is in seconds as a floating point value. */);
6964 DEFVAR_INT ("gcs-done", gcs_done,
6965 doc: /* Accumulated number of garbage collections done. */);
6967 defsubr (&Scons);
6968 defsubr (&Slist);
6969 defsubr (&Svector);
6970 defsubr (&Smake_byte_code);
6971 defsubr (&Smake_list);
6972 defsubr (&Smake_vector);
6973 defsubr (&Smake_string);
6974 defsubr (&Smake_bool_vector);
6975 defsubr (&Smake_symbol);
6976 defsubr (&Smake_marker);
6977 defsubr (&Spurecopy);
6978 defsubr (&Sgarbage_collect);
6979 defsubr (&Smemory_limit);
6980 defsubr (&Smemory_use_counts);
6982 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
6983 defsubr (&Sgc_status);
6984 #endif
6987 /* When compiled with GCC, GDB might say "No enum type named
6988 pvec_type" if we don't have at least one symbol with that type, and
6989 then xbacktrace could fail. Similarly for the other enums and
6990 their values. Some non-GCC compilers don't like these constructs. */
6991 #ifdef __GNUC__
6992 union
6994 enum CHARTAB_SIZE_BITS CHARTAB_SIZE_BITS;
6995 enum CHAR_TABLE_STANDARD_SLOTS CHAR_TABLE_STANDARD_SLOTS;
6996 enum char_bits char_bits;
6997 enum CHECK_LISP_OBJECT_TYPE CHECK_LISP_OBJECT_TYPE;
6998 enum DEFAULT_HASH_SIZE DEFAULT_HASH_SIZE;
6999 enum enum_USE_LSB_TAG enum_USE_LSB_TAG;
7000 enum FLOAT_TO_STRING_BUFSIZE FLOAT_TO_STRING_BUFSIZE;
7001 enum Lisp_Bits Lisp_Bits;
7002 enum Lisp_Compiled Lisp_Compiled;
7003 enum maxargs maxargs;
7004 enum MAX_ALLOCA MAX_ALLOCA;
7005 enum More_Lisp_Bits More_Lisp_Bits;
7006 enum pvec_type pvec_type;
7007 } const EXTERNALLY_VISIBLE gdb_make_enums_visible = {0};
7008 #endif /* __GNUC__ */