Better seed support for (random).
[emacs.git] / src / alloc.c
blobe8637471bc70f5cec1ac496b9a003a425e31103f
1 /* Storage allocation and gc for GNU Emacs Lisp interpreter.
3 Copyright (C) 1985-1986, 1988, 1993-1995, 1997-2012
4 Free Software 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 #define LISP_INLINE EXTERN_INLINE
25 #include <stdio.h>
26 #include <limits.h> /* For CHAR_BIT. */
27 #include <setjmp.h>
29 #include <signal.h>
31 #ifdef HAVE_PTHREAD
32 #include <pthread.h>
33 #endif
35 #include "lisp.h"
36 #include "process.h"
37 #include "intervals.h"
38 #include "puresize.h"
39 #include "character.h"
40 #include "buffer.h"
41 #include "window.h"
42 #include "keyboard.h"
43 #include "frame.h"
44 #include "blockinput.h"
45 #include "syssignal.h"
46 #include "termhooks.h" /* For struct terminal. */
47 #include <setjmp.h>
48 #include <verify.h>
50 /* GC_CHECK_MARKED_OBJECTS means do sanity checks on allocated objects.
51 Doable only if GC_MARK_STACK. */
52 #if ! GC_MARK_STACK
53 # undef GC_CHECK_MARKED_OBJECTS
54 #endif
56 /* GC_MALLOC_CHECK defined means perform validity checks of malloc'd
57 memory. Can do this only if using gmalloc.c and if not checking
58 marked objects. */
60 #if (defined SYSTEM_MALLOC || defined DOUG_LEA_MALLOC \
61 || defined GC_CHECK_MARKED_OBJECTS)
62 #undef GC_MALLOC_CHECK
63 #endif
65 #include <unistd.h>
66 #ifndef HAVE_UNISTD_H
67 extern void *sbrk ();
68 #endif
70 #include <fcntl.h>
72 #ifdef WINDOWSNT
73 #include "w32.h"
74 #endif
76 #ifdef DOUG_LEA_MALLOC
78 #include <malloc.h>
80 /* Specify maximum number of areas to mmap. It would be nice to use a
81 value that explicitly means "no limit". */
83 #define MMAP_MAX_AREAS 100000000
85 #else /* not DOUG_LEA_MALLOC */
87 /* The following come from gmalloc.c. */
89 extern size_t _bytes_used;
90 extern size_t __malloc_extra_blocks;
91 extern void *_malloc_internal (size_t);
92 extern void _free_internal (void *);
94 #endif /* not DOUG_LEA_MALLOC */
96 #if ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT
97 #ifdef HAVE_PTHREAD
99 /* When GTK uses the file chooser dialog, different backends can be loaded
100 dynamically. One such a backend is the Gnome VFS backend that gets loaded
101 if you run Gnome. That backend creates several threads and also allocates
102 memory with malloc.
104 Also, gconf and gsettings may create several threads.
106 If Emacs sets malloc hooks (! SYSTEM_MALLOC) and the emacs_blocked_*
107 functions below are called from malloc, there is a chance that one
108 of these threads preempts the Emacs main thread and the hook variables
109 end up in an inconsistent state. So we have a mutex to prevent that (note
110 that the backend handles concurrent access to malloc within its own threads
111 but Emacs code running in the main thread is not included in that control).
113 When UNBLOCK_INPUT is called, reinvoke_input_signal may be called. If this
114 happens in one of the backend threads we will have two threads that tries
115 to run Emacs code at once, and the code is not prepared for that.
116 To prevent that, we only call BLOCK/UNBLOCK from the main thread. */
118 static pthread_mutex_t alloc_mutex;
120 #define BLOCK_INPUT_ALLOC \
121 do \
123 if (pthread_equal (pthread_self (), main_thread)) \
124 BLOCK_INPUT; \
125 pthread_mutex_lock (&alloc_mutex); \
127 while (0)
128 #define UNBLOCK_INPUT_ALLOC \
129 do \
131 pthread_mutex_unlock (&alloc_mutex); \
132 if (pthread_equal (pthread_self (), main_thread)) \
133 UNBLOCK_INPUT; \
135 while (0)
137 #else /* ! defined HAVE_PTHREAD */
139 #define BLOCK_INPUT_ALLOC BLOCK_INPUT
140 #define UNBLOCK_INPUT_ALLOC UNBLOCK_INPUT
142 #endif /* ! defined HAVE_PTHREAD */
143 #endif /* ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT */
145 /* Mark, unmark, query mark bit of a Lisp string. S must be a pointer
146 to a struct Lisp_String. */
148 #define MARK_STRING(S) ((S)->size |= ARRAY_MARK_FLAG)
149 #define UNMARK_STRING(S) ((S)->size &= ~ARRAY_MARK_FLAG)
150 #define STRING_MARKED_P(S) (((S)->size & ARRAY_MARK_FLAG) != 0)
152 #define VECTOR_MARK(V) ((V)->header.size |= ARRAY_MARK_FLAG)
153 #define VECTOR_UNMARK(V) ((V)->header.size &= ~ARRAY_MARK_FLAG)
154 #define VECTOR_MARKED_P(V) (((V)->header.size & ARRAY_MARK_FLAG) != 0)
156 /* Default value of gc_cons_threshold (see below). */
158 #define GC_DEFAULT_THRESHOLD (100000 * word_size)
160 /* Global variables. */
161 struct emacs_globals globals;
163 /* Number of bytes of consing done since the last gc. */
165 EMACS_INT consing_since_gc;
167 /* Similar minimum, computed from Vgc_cons_percentage. */
169 EMACS_INT gc_relative_threshold;
171 /* Minimum number of bytes of consing since GC before next GC,
172 when memory is full. */
174 EMACS_INT memory_full_cons_threshold;
176 /* True during GC. */
178 bool gc_in_progress;
180 /* True means abort if try to GC.
181 This is for code which is written on the assumption that
182 no GC will happen, so as to verify that assumption. */
184 bool abort_on_gc;
186 /* Number of live and free conses etc. */
188 static EMACS_INT total_conses, total_markers, total_symbols, total_buffers;
189 static EMACS_INT total_free_conses, total_free_markers, total_free_symbols;
190 static EMACS_INT total_free_floats, total_floats;
192 /* Points to memory space allocated as "spare", to be freed if we run
193 out of memory. We keep one large block, four cons-blocks, and
194 two string blocks. */
196 static char *spare_memory[7];
198 /* Amount of spare memory to keep in large reserve block, or to see
199 whether this much is available when malloc fails on a larger request. */
201 #define SPARE_MEMORY (1 << 14)
203 /* Number of extra blocks malloc should get when it needs more core. */
205 static int malloc_hysteresis;
207 /* Initialize it to a nonzero value to force it into data space
208 (rather than bss space). That way unexec will remap it into text
209 space (pure), on some systems. We have not implemented the
210 remapping on more recent systems because this is less important
211 nowadays than in the days of small memories and timesharing. */
213 EMACS_INT pure[(PURESIZE + sizeof (EMACS_INT) - 1) / sizeof (EMACS_INT)] = {1,};
214 #define PUREBEG (char *) pure
216 /* Pointer to the pure area, and its size. */
218 static char *purebeg;
219 static ptrdiff_t pure_size;
221 /* Number of bytes of pure storage used before pure storage overflowed.
222 If this is non-zero, this implies that an overflow occurred. */
224 static ptrdiff_t pure_bytes_used_before_overflow;
226 /* True if P points into pure space. */
228 #define PURE_POINTER_P(P) \
229 ((uintptr_t) (P) - (uintptr_t) purebeg <= pure_size)
231 /* Index in pure at which next pure Lisp object will be allocated.. */
233 static ptrdiff_t pure_bytes_used_lisp;
235 /* Number of bytes allocated for non-Lisp objects in pure storage. */
237 static ptrdiff_t pure_bytes_used_non_lisp;
239 /* If nonzero, this is a warning delivered by malloc and not yet
240 displayed. */
242 const char *pending_malloc_warning;
244 /* Maximum amount of C stack to save when a GC happens. */
246 #ifndef MAX_SAVE_STACK
247 #define MAX_SAVE_STACK 16000
248 #endif
250 /* Buffer in which we save a copy of the C stack at each GC. */
252 #if MAX_SAVE_STACK > 0
253 static char *stack_copy;
254 static ptrdiff_t stack_copy_size;
255 #endif
257 static Lisp_Object Qconses;
258 static Lisp_Object Qsymbols;
259 static Lisp_Object Qmiscs;
260 static Lisp_Object Qstrings;
261 static Lisp_Object Qvectors;
262 static Lisp_Object Qfloats;
263 static Lisp_Object Qintervals;
264 static Lisp_Object Qbuffers;
265 static Lisp_Object Qstring_bytes, Qvector_slots, Qheap;
266 static Lisp_Object Qgc_cons_threshold;
267 Lisp_Object Qchar_table_extra_slots;
269 /* Hook run after GC has finished. */
271 static Lisp_Object Qpost_gc_hook;
273 static void mark_terminals (void);
274 static void gc_sweep (void);
275 static Lisp_Object make_pure_vector (ptrdiff_t);
276 static void mark_glyph_matrix (struct glyph_matrix *);
277 static void mark_face_cache (struct face_cache *);
279 #if !defined REL_ALLOC || defined SYSTEM_MALLOC
280 static void refill_memory_reserve (void);
281 #endif
282 static struct Lisp_String *allocate_string (void);
283 static void compact_small_strings (void);
284 static void free_large_strings (void);
285 static void sweep_strings (void);
286 static void free_misc (Lisp_Object);
287 extern Lisp_Object which_symbols (Lisp_Object, EMACS_INT) EXTERNALLY_VISIBLE;
289 /* When scanning the C stack for live Lisp objects, Emacs keeps track
290 of what memory allocated via lisp_malloc is intended for what
291 purpose. This enumeration specifies the type of memory. */
293 enum mem_type
295 MEM_TYPE_NON_LISP,
296 MEM_TYPE_BUFFER,
297 MEM_TYPE_CONS,
298 MEM_TYPE_STRING,
299 MEM_TYPE_MISC,
300 MEM_TYPE_SYMBOL,
301 MEM_TYPE_FLOAT,
302 /* We used to keep separate mem_types for subtypes of vectors such as
303 process, hash_table, frame, terminal, and window, but we never made
304 use of the distinction, so it only caused source-code complexity
305 and runtime slowdown. Minor but pointless. */
306 MEM_TYPE_VECTORLIKE,
307 /* Special type to denote vector blocks. */
308 MEM_TYPE_VECTOR_BLOCK,
309 /* Special type to denote reserved memory. */
310 MEM_TYPE_SPARE
313 static void *lisp_malloc (size_t, enum mem_type);
316 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
318 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
319 #include <stdio.h> /* For fprintf. */
320 #endif
322 /* A unique object in pure space used to make some Lisp objects
323 on free lists recognizable in O(1). */
325 static Lisp_Object Vdead;
326 #define DEADP(x) EQ (x, Vdead)
328 #ifdef GC_MALLOC_CHECK
330 enum mem_type allocated_mem_type;
332 #endif /* GC_MALLOC_CHECK */
334 /* A node in the red-black tree describing allocated memory containing
335 Lisp data. Each such block is recorded with its start and end
336 address when it is allocated, and removed from the tree when it
337 is freed.
339 A red-black tree is a balanced binary tree with the following
340 properties:
342 1. Every node is either red or black.
343 2. Every leaf is black.
344 3. If a node is red, then both of its children are black.
345 4. Every simple path from a node to a descendant leaf contains
346 the same number of black nodes.
347 5. The root is always black.
349 When nodes are inserted into the tree, or deleted from the tree,
350 the tree is "fixed" so that these properties are always true.
352 A red-black tree with N internal nodes has height at most 2
353 log(N+1). Searches, insertions and deletions are done in O(log N).
354 Please see a text book about data structures for a detailed
355 description of red-black trees. Any book worth its salt should
356 describe them. */
358 struct mem_node
360 /* Children of this node. These pointers are never NULL. When there
361 is no child, the value is MEM_NIL, which points to a dummy node. */
362 struct mem_node *left, *right;
364 /* The parent of this node. In the root node, this is NULL. */
365 struct mem_node *parent;
367 /* Start and end of allocated region. */
368 void *start, *end;
370 /* Node color. */
371 enum {MEM_BLACK, MEM_RED} color;
373 /* Memory type. */
374 enum mem_type type;
377 /* Base address of stack. Set in main. */
379 Lisp_Object *stack_base;
381 /* Root of the tree describing allocated Lisp memory. */
383 static struct mem_node *mem_root;
385 /* Lowest and highest known address in the heap. */
387 static void *min_heap_address, *max_heap_address;
389 /* Sentinel node of the tree. */
391 static struct mem_node mem_z;
392 #define MEM_NIL &mem_z
394 static struct Lisp_Vector *allocate_vectorlike (ptrdiff_t);
395 static void lisp_free (void *);
396 static void mark_stack (void);
397 static bool live_vector_p (struct mem_node *, void *);
398 static bool live_buffer_p (struct mem_node *, void *);
399 static bool live_string_p (struct mem_node *, void *);
400 static bool live_cons_p (struct mem_node *, void *);
401 static bool live_symbol_p (struct mem_node *, void *);
402 static bool live_float_p (struct mem_node *, void *);
403 static bool live_misc_p (struct mem_node *, void *);
404 static void mark_maybe_object (Lisp_Object);
405 static void mark_memory (void *, void *);
406 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
407 static void mem_init (void);
408 static struct mem_node *mem_insert (void *, void *, enum mem_type);
409 static void mem_insert_fixup (struct mem_node *);
410 #endif
411 static void mem_rotate_left (struct mem_node *);
412 static void mem_rotate_right (struct mem_node *);
413 static void mem_delete (struct mem_node *);
414 static void mem_delete_fixup (struct mem_node *);
415 static inline struct mem_node *mem_find (void *);
418 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
419 static void check_gcpros (void);
420 #endif
422 #endif /* GC_MARK_STACK || GC_MALLOC_CHECK */
424 #ifndef DEADP
425 # define DEADP(x) 0
426 #endif
428 /* Recording what needs to be marked for gc. */
430 struct gcpro *gcprolist;
432 /* Addresses of staticpro'd variables. Initialize it to a nonzero
433 value; otherwise some compilers put it into BSS. */
435 #define NSTATICS 0x650
436 static Lisp_Object *staticvec[NSTATICS] = {&Vpurify_flag};
438 /* Index of next unused slot in staticvec. */
440 static int staticidx;
442 static void *pure_alloc (size_t, int);
445 /* Value is SZ rounded up to the next multiple of ALIGNMENT.
446 ALIGNMENT must be a power of 2. */
448 #define ALIGN(ptr, ALIGNMENT) \
449 ((void *) (((uintptr_t) (ptr) + (ALIGNMENT) - 1) \
450 & ~ ((ALIGNMENT) - 1)))
454 /************************************************************************
455 Malloc
456 ************************************************************************/
458 /* Function malloc calls this if it finds we are near exhausting storage. */
460 void
461 malloc_warning (const char *str)
463 pending_malloc_warning = str;
467 /* Display an already-pending malloc warning. */
469 void
470 display_malloc_warning (void)
472 call3 (intern ("display-warning"),
473 intern ("alloc"),
474 build_string (pending_malloc_warning),
475 intern ("emergency"));
476 pending_malloc_warning = 0;
479 /* Called if we can't allocate relocatable space for a buffer. */
481 void
482 buffer_memory_full (ptrdiff_t nbytes)
484 /* If buffers use the relocating allocator, no need to free
485 spare_memory, because we may have plenty of malloc space left
486 that we could get, and if we don't, the malloc that fails will
487 itself cause spare_memory to be freed. If buffers don't use the
488 relocating allocator, treat this like any other failing
489 malloc. */
491 #ifndef REL_ALLOC
492 memory_full (nbytes);
493 #endif
495 /* This used to call error, but if we've run out of memory, we could
496 get infinite recursion trying to build the string. */
497 xsignal (Qnil, Vmemory_signal_data);
500 /* A common multiple of the positive integers A and B. Ideally this
501 would be the least common multiple, but there's no way to do that
502 as a constant expression in C, so do the best that we can easily do. */
503 #define COMMON_MULTIPLE(a, b) \
504 ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
506 #ifndef XMALLOC_OVERRUN_CHECK
507 #define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
508 #else
510 /* Check for overrun in malloc'ed buffers by wrapping a header and trailer
511 around each block.
513 The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
514 followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
515 block size in little-endian order. The trailer consists of
516 XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
518 The header is used to detect whether this block has been allocated
519 through these functions, as some low-level libc functions may
520 bypass the malloc hooks. */
522 #define XMALLOC_OVERRUN_CHECK_SIZE 16
523 #define XMALLOC_OVERRUN_CHECK_OVERHEAD \
524 (2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
526 /* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
527 hold a size_t value and (2) the header size is a multiple of the
528 alignment that Emacs needs for C types and for USE_LSB_TAG. */
529 #define XMALLOC_BASE_ALIGNMENT \
530 alignof (union { long double d; intmax_t i; void *p; })
532 #if USE_LSB_TAG
533 # define XMALLOC_HEADER_ALIGNMENT \
534 COMMON_MULTIPLE (GCALIGNMENT, XMALLOC_BASE_ALIGNMENT)
535 #else
536 # define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
537 #endif
538 #define XMALLOC_OVERRUN_SIZE_SIZE \
539 (((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
540 + XMALLOC_HEADER_ALIGNMENT - 1) \
541 / XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
542 - XMALLOC_OVERRUN_CHECK_SIZE)
544 static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
545 { '\x9a', '\x9b', '\xae', '\xaf',
546 '\xbf', '\xbe', '\xce', '\xcf',
547 '\xea', '\xeb', '\xec', '\xed',
548 '\xdf', '\xde', '\x9c', '\x9d' };
550 static char const xmalloc_overrun_check_trailer[XMALLOC_OVERRUN_CHECK_SIZE] =
551 { '\xaa', '\xab', '\xac', '\xad',
552 '\xba', '\xbb', '\xbc', '\xbd',
553 '\xca', '\xcb', '\xcc', '\xcd',
554 '\xda', '\xdb', '\xdc', '\xdd' };
556 /* Insert and extract the block size in the header. */
558 static void
559 xmalloc_put_size (unsigned char *ptr, size_t size)
561 int i;
562 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
564 *--ptr = size & ((1 << CHAR_BIT) - 1);
565 size >>= CHAR_BIT;
569 static size_t
570 xmalloc_get_size (unsigned char *ptr)
572 size_t size = 0;
573 int i;
574 ptr -= XMALLOC_OVERRUN_SIZE_SIZE;
575 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
577 size <<= CHAR_BIT;
578 size += *ptr++;
580 return size;
584 /* The call depth in overrun_check functions. For example, this might happen:
585 xmalloc()
586 overrun_check_malloc()
587 -> malloc -> (via hook)_-> emacs_blocked_malloc
588 -> overrun_check_malloc
589 call malloc (hooks are NULL, so real malloc is called).
590 malloc returns 10000.
591 add overhead, return 10016.
592 <- (back in overrun_check_malloc)
593 add overhead again, return 10032
594 xmalloc returns 10032.
596 (time passes).
598 xfree(10032)
599 overrun_check_free(10032)
600 decrease overhead
601 free(10016) <- crash, because 10000 is the original pointer. */
603 static ptrdiff_t check_depth;
605 /* Like malloc, but wraps allocated block with header and trailer. */
607 static void *
608 overrun_check_malloc (size_t size)
610 register unsigned char *val;
611 int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0;
612 if (SIZE_MAX - overhead < size)
613 abort ();
615 val = malloc (size + overhead);
616 if (val && check_depth == 1)
618 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
619 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
620 xmalloc_put_size (val, size);
621 memcpy (val + size, xmalloc_overrun_check_trailer,
622 XMALLOC_OVERRUN_CHECK_SIZE);
624 --check_depth;
625 return val;
629 /* Like realloc, but checks old block for overrun, and wraps new block
630 with header and trailer. */
632 static void *
633 overrun_check_realloc (void *block, size_t size)
635 register unsigned char *val = (unsigned char *) block;
636 int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0;
637 if (SIZE_MAX - overhead < size)
638 abort ();
640 if (val
641 && check_depth == 1
642 && memcmp (xmalloc_overrun_check_header,
643 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
644 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
646 size_t osize = xmalloc_get_size (val);
647 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
648 XMALLOC_OVERRUN_CHECK_SIZE))
649 abort ();
650 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
651 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
652 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
655 val = realloc (val, size + overhead);
657 if (val && check_depth == 1)
659 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
660 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
661 xmalloc_put_size (val, size);
662 memcpy (val + size, xmalloc_overrun_check_trailer,
663 XMALLOC_OVERRUN_CHECK_SIZE);
665 --check_depth;
666 return val;
669 /* Like free, but checks block for overrun. */
671 static void
672 overrun_check_free (void *block)
674 unsigned char *val = (unsigned char *) block;
676 ++check_depth;
677 if (val
678 && check_depth == 1
679 && memcmp (xmalloc_overrun_check_header,
680 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
681 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
683 size_t osize = xmalloc_get_size (val);
684 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
685 XMALLOC_OVERRUN_CHECK_SIZE))
686 abort ();
687 #ifdef XMALLOC_CLEAR_FREE_MEMORY
688 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
689 memset (val, 0xff, osize + XMALLOC_OVERRUN_CHECK_OVERHEAD);
690 #else
691 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
692 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
693 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
694 #endif
697 free (val);
698 --check_depth;
701 #undef malloc
702 #undef realloc
703 #undef free
704 #define malloc overrun_check_malloc
705 #define realloc overrun_check_realloc
706 #define free overrun_check_free
707 #endif
709 #ifdef SYNC_INPUT
710 /* When using SYNC_INPUT, we don't call malloc from a signal handler, so
711 there's no need to block input around malloc. */
712 #define MALLOC_BLOCK_INPUT ((void)0)
713 #define MALLOC_UNBLOCK_INPUT ((void)0)
714 #else
715 #define MALLOC_BLOCK_INPUT BLOCK_INPUT
716 #define MALLOC_UNBLOCK_INPUT UNBLOCK_INPUT
717 #endif
719 /* Like malloc but check for no memory and block interrupt input.. */
721 void *
722 xmalloc (size_t size)
724 void *val;
726 MALLOC_BLOCK_INPUT;
727 val = malloc (size);
728 MALLOC_UNBLOCK_INPUT;
730 if (!val && size)
731 memory_full (size);
732 return val;
735 /* Like the above, but zeroes out the memory just allocated. */
737 void *
738 xzalloc (size_t size)
740 void *val;
742 MALLOC_BLOCK_INPUT;
743 val = malloc (size);
744 MALLOC_UNBLOCK_INPUT;
746 if (!val && size)
747 memory_full (size);
748 memset (val, 0, size);
749 return val;
752 /* Like realloc but check for no memory and block interrupt input.. */
754 void *
755 xrealloc (void *block, size_t size)
757 void *val;
759 MALLOC_BLOCK_INPUT;
760 /* We must call malloc explicitly when BLOCK is 0, since some
761 reallocs don't do this. */
762 if (! block)
763 val = malloc (size);
764 else
765 val = realloc (block, size);
766 MALLOC_UNBLOCK_INPUT;
768 if (!val && size)
769 memory_full (size);
770 return val;
774 /* Like free but block interrupt input. */
776 void
777 xfree (void *block)
779 if (!block)
780 return;
781 MALLOC_BLOCK_INPUT;
782 free (block);
783 MALLOC_UNBLOCK_INPUT;
784 /* We don't call refill_memory_reserve here
785 because that duplicates doing so in emacs_blocked_free
786 and the criterion should go there. */
790 /* Other parts of Emacs pass large int values to allocator functions
791 expecting ptrdiff_t. This is portable in practice, but check it to
792 be safe. */
793 verify (INT_MAX <= PTRDIFF_MAX);
796 /* Allocate an array of NITEMS items, each of size ITEM_SIZE.
797 Signal an error on memory exhaustion, and block interrupt input. */
799 void *
800 xnmalloc (ptrdiff_t nitems, ptrdiff_t item_size)
802 eassert (0 <= nitems && 0 < item_size);
803 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
804 memory_full (SIZE_MAX);
805 return xmalloc (nitems * item_size);
809 /* Reallocate an array PA to make it of NITEMS items, each of size ITEM_SIZE.
810 Signal an error on memory exhaustion, and block interrupt input. */
812 void *
813 xnrealloc (void *pa, ptrdiff_t nitems, ptrdiff_t item_size)
815 eassert (0 <= nitems && 0 < item_size);
816 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
817 memory_full (SIZE_MAX);
818 return xrealloc (pa, nitems * item_size);
822 /* Grow PA, which points to an array of *NITEMS items, and return the
823 location of the reallocated array, updating *NITEMS to reflect its
824 new size. The new array will contain at least NITEMS_INCR_MIN more
825 items, but will not contain more than NITEMS_MAX items total.
826 ITEM_SIZE is the size of each item, in bytes.
828 ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be
829 nonnegative. If NITEMS_MAX is -1, it is treated as if it were
830 infinity.
832 If PA is null, then allocate a new array instead of reallocating
833 the old one. Thus, to grow an array A without saving its old
834 contents, invoke xfree (A) immediately followed by xgrowalloc (0,
835 &NITEMS, ...).
837 Block interrupt input as needed. If memory exhaustion occurs, set
838 *NITEMS to zero if PA is null, and signal an error (i.e., do not
839 return). */
841 void *
842 xpalloc (void *pa, ptrdiff_t *nitems, ptrdiff_t nitems_incr_min,
843 ptrdiff_t nitems_max, ptrdiff_t item_size)
845 /* The approximate size to use for initial small allocation
846 requests. This is the largest "small" request for the GNU C
847 library malloc. */
848 enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
850 /* If the array is tiny, grow it to about (but no greater than)
851 DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%. */
852 ptrdiff_t n = *nitems;
853 ptrdiff_t tiny_max = DEFAULT_MXFAST / item_size - n;
854 ptrdiff_t half_again = n >> 1;
855 ptrdiff_t incr_estimate = max (tiny_max, half_again);
857 /* Adjust the increment according to three constraints: NITEMS_INCR_MIN,
858 NITEMS_MAX, and what the C language can represent safely. */
859 ptrdiff_t C_language_max = min (PTRDIFF_MAX, SIZE_MAX) / item_size;
860 ptrdiff_t n_max = (0 <= nitems_max && nitems_max < C_language_max
861 ? nitems_max : C_language_max);
862 ptrdiff_t nitems_incr_max = n_max - n;
863 ptrdiff_t incr = max (nitems_incr_min, min (incr_estimate, nitems_incr_max));
865 eassert (0 < item_size && 0 < nitems_incr_min && 0 <= n && -1 <= nitems_max);
866 if (! pa)
867 *nitems = 0;
868 if (nitems_incr_max < incr)
869 memory_full (SIZE_MAX);
870 n += incr;
871 pa = xrealloc (pa, n * item_size);
872 *nitems = n;
873 return pa;
877 /* Like strdup, but uses xmalloc. */
879 char *
880 xstrdup (const char *s)
882 size_t len = strlen (s) + 1;
883 char *p = xmalloc (len);
884 memcpy (p, s, len);
885 return p;
889 /* Unwind for SAFE_ALLOCA */
891 Lisp_Object
892 safe_alloca_unwind (Lisp_Object arg)
894 register struct Lisp_Save_Value *p = XSAVE_VALUE (arg);
896 p->dogc = 0;
897 xfree (p->pointer);
898 p->pointer = 0;
899 free_misc (arg);
900 return Qnil;
903 /* Return a newly allocated memory block of SIZE bytes, remembering
904 to free it when unwinding. */
905 void *
906 record_xmalloc (size_t size)
908 void *p = xmalloc (size);
909 record_unwind_protect (safe_alloca_unwind, make_save_value (p, 0));
910 return p;
914 /* Like malloc but used for allocating Lisp data. NBYTES is the
915 number of bytes to allocate, TYPE describes the intended use of the
916 allocated memory block (for strings, for conses, ...). */
918 #if ! USE_LSB_TAG
919 void *lisp_malloc_loser EXTERNALLY_VISIBLE;
920 #endif
922 static void *
923 lisp_malloc (size_t nbytes, enum mem_type type)
925 register void *val;
927 MALLOC_BLOCK_INPUT;
929 #ifdef GC_MALLOC_CHECK
930 allocated_mem_type = type;
931 #endif
933 val = malloc (nbytes);
935 #if ! USE_LSB_TAG
936 /* If the memory just allocated cannot be addressed thru a Lisp
937 object's pointer, and it needs to be,
938 that's equivalent to running out of memory. */
939 if (val && type != MEM_TYPE_NON_LISP)
941 Lisp_Object tem;
942 XSETCONS (tem, (char *) val + nbytes - 1);
943 if ((char *) XCONS (tem) != (char *) val + nbytes - 1)
945 lisp_malloc_loser = val;
946 free (val);
947 val = 0;
950 #endif
952 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
953 if (val && type != MEM_TYPE_NON_LISP)
954 mem_insert (val, (char *) val + nbytes, type);
955 #endif
957 MALLOC_UNBLOCK_INPUT;
958 if (!val && nbytes)
959 memory_full (nbytes);
960 return val;
963 /* Free BLOCK. This must be called to free memory allocated with a
964 call to lisp_malloc. */
966 static void
967 lisp_free (void *block)
969 MALLOC_BLOCK_INPUT;
970 free (block);
971 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
972 mem_delete (mem_find (block));
973 #endif
974 MALLOC_UNBLOCK_INPUT;
977 /***** Allocation of aligned blocks of memory to store Lisp data. *****/
979 /* The entry point is lisp_align_malloc which returns blocks of at most
980 BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary. */
982 #if defined (HAVE_POSIX_MEMALIGN) && defined (SYSTEM_MALLOC)
983 #define USE_POSIX_MEMALIGN 1
984 #endif
986 /* BLOCK_ALIGN has to be a power of 2. */
987 #define BLOCK_ALIGN (1 << 10)
989 /* Padding to leave at the end of a malloc'd block. This is to give
990 malloc a chance to minimize the amount of memory wasted to alignment.
991 It should be tuned to the particular malloc library used.
992 On glibc-2.3.2, malloc never tries to align, so a padding of 0 is best.
993 posix_memalign on the other hand would ideally prefer a value of 4
994 because otherwise, there's 1020 bytes wasted between each ablocks.
995 In Emacs, testing shows that those 1020 can most of the time be
996 efficiently used by malloc to place other objects, so a value of 0 can
997 still preferable unless you have a lot of aligned blocks and virtually
998 nothing else. */
999 #define BLOCK_PADDING 0
1000 #define BLOCK_BYTES \
1001 (BLOCK_ALIGN - sizeof (struct ablocks *) - BLOCK_PADDING)
1003 /* Internal data structures and constants. */
1005 #define ABLOCKS_SIZE 16
1007 /* An aligned block of memory. */
1008 struct ablock
1010 union
1012 char payload[BLOCK_BYTES];
1013 struct ablock *next_free;
1014 } x;
1015 /* `abase' is the aligned base of the ablocks. */
1016 /* It is overloaded to hold the virtual `busy' field that counts
1017 the number of used ablock in the parent ablocks.
1018 The first ablock has the `busy' field, the others have the `abase'
1019 field. To tell the difference, we assume that pointers will have
1020 integer values larger than 2 * ABLOCKS_SIZE. The lowest bit of `busy'
1021 is used to tell whether the real base of the parent ablocks is `abase'
1022 (if not, the word before the first ablock holds a pointer to the
1023 real base). */
1024 struct ablocks *abase;
1025 /* The padding of all but the last ablock is unused. The padding of
1026 the last ablock in an ablocks is not allocated. */
1027 #if BLOCK_PADDING
1028 char padding[BLOCK_PADDING];
1029 #endif
1032 /* A bunch of consecutive aligned blocks. */
1033 struct ablocks
1035 struct ablock blocks[ABLOCKS_SIZE];
1038 /* Size of the block requested from malloc or posix_memalign. */
1039 #define ABLOCKS_BYTES (sizeof (struct ablocks) - BLOCK_PADDING)
1041 #define ABLOCK_ABASE(block) \
1042 (((uintptr_t) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE) \
1043 ? (struct ablocks *)(block) \
1044 : (block)->abase)
1046 /* Virtual `busy' field. */
1047 #define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
1049 /* Pointer to the (not necessarily aligned) malloc block. */
1050 #ifdef USE_POSIX_MEMALIGN
1051 #define ABLOCKS_BASE(abase) (abase)
1052 #else
1053 #define ABLOCKS_BASE(abase) \
1054 (1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void**)abase)[-1])
1055 #endif
1057 /* The list of free ablock. */
1058 static struct ablock *free_ablock;
1060 /* Allocate an aligned block of nbytes.
1061 Alignment is on a multiple of BLOCK_ALIGN and `nbytes' has to be
1062 smaller or equal to BLOCK_BYTES. */
1063 static void *
1064 lisp_align_malloc (size_t nbytes, enum mem_type type)
1066 void *base, *val;
1067 struct ablocks *abase;
1069 eassert (nbytes <= BLOCK_BYTES);
1071 MALLOC_BLOCK_INPUT;
1073 #ifdef GC_MALLOC_CHECK
1074 allocated_mem_type = type;
1075 #endif
1077 if (!free_ablock)
1079 int i;
1080 intptr_t aligned; /* int gets warning casting to 64-bit pointer. */
1082 #ifdef DOUG_LEA_MALLOC
1083 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1084 because mapped region contents are not preserved in
1085 a dumped Emacs. */
1086 mallopt (M_MMAP_MAX, 0);
1087 #endif
1089 #ifdef USE_POSIX_MEMALIGN
1091 int err = posix_memalign (&base, BLOCK_ALIGN, ABLOCKS_BYTES);
1092 if (err)
1093 base = NULL;
1094 abase = base;
1096 #else
1097 base = malloc (ABLOCKS_BYTES);
1098 abase = ALIGN (base, BLOCK_ALIGN);
1099 #endif
1101 if (base == 0)
1103 MALLOC_UNBLOCK_INPUT;
1104 memory_full (ABLOCKS_BYTES);
1107 aligned = (base == abase);
1108 if (!aligned)
1109 ((void**)abase)[-1] = base;
1111 #ifdef DOUG_LEA_MALLOC
1112 /* Back to a reasonable maximum of mmap'ed areas. */
1113 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
1114 #endif
1116 #if ! USE_LSB_TAG
1117 /* If the memory just allocated cannot be addressed thru a Lisp
1118 object's pointer, and it needs to be, that's equivalent to
1119 running out of memory. */
1120 if (type != MEM_TYPE_NON_LISP)
1122 Lisp_Object tem;
1123 char *end = (char *) base + ABLOCKS_BYTES - 1;
1124 XSETCONS (tem, end);
1125 if ((char *) XCONS (tem) != end)
1127 lisp_malloc_loser = base;
1128 free (base);
1129 MALLOC_UNBLOCK_INPUT;
1130 memory_full (SIZE_MAX);
1133 #endif
1135 /* Initialize the blocks and put them on the free list.
1136 If `base' was not properly aligned, we can't use the last block. */
1137 for (i = 0; i < (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1); i++)
1139 abase->blocks[i].abase = abase;
1140 abase->blocks[i].x.next_free = free_ablock;
1141 free_ablock = &abase->blocks[i];
1143 ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
1145 eassert (0 == ((uintptr_t) abase) % BLOCK_ALIGN);
1146 eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
1147 eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
1148 eassert (ABLOCKS_BASE (abase) == base);
1149 eassert (aligned == (intptr_t) ABLOCKS_BUSY (abase));
1152 abase = ABLOCK_ABASE (free_ablock);
1153 ABLOCKS_BUSY (abase) =
1154 (struct ablocks *) (2 + (intptr_t) ABLOCKS_BUSY (abase));
1155 val = free_ablock;
1156 free_ablock = free_ablock->x.next_free;
1158 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1159 if (type != MEM_TYPE_NON_LISP)
1160 mem_insert (val, (char *) val + nbytes, type);
1161 #endif
1163 MALLOC_UNBLOCK_INPUT;
1165 eassert (0 == ((uintptr_t) val) % BLOCK_ALIGN);
1166 return val;
1169 static void
1170 lisp_align_free (void *block)
1172 struct ablock *ablock = block;
1173 struct ablocks *abase = ABLOCK_ABASE (ablock);
1175 MALLOC_BLOCK_INPUT;
1176 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1177 mem_delete (mem_find (block));
1178 #endif
1179 /* Put on free list. */
1180 ablock->x.next_free = free_ablock;
1181 free_ablock = ablock;
1182 /* Update busy count. */
1183 ABLOCKS_BUSY (abase)
1184 = (struct ablocks *) (-2 + (intptr_t) ABLOCKS_BUSY (abase));
1186 if (2 > (intptr_t) ABLOCKS_BUSY (abase))
1187 { /* All the blocks are free. */
1188 int i = 0, aligned = (intptr_t) ABLOCKS_BUSY (abase);
1189 struct ablock **tem = &free_ablock;
1190 struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
1192 while (*tem)
1194 if (*tem >= (struct ablock *) abase && *tem < atop)
1196 i++;
1197 *tem = (*tem)->x.next_free;
1199 else
1200 tem = &(*tem)->x.next_free;
1202 eassert ((aligned & 1) == aligned);
1203 eassert (i == (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1));
1204 #ifdef USE_POSIX_MEMALIGN
1205 eassert ((uintptr_t) ABLOCKS_BASE (abase) % BLOCK_ALIGN == 0);
1206 #endif
1207 free (ABLOCKS_BASE (abase));
1209 MALLOC_UNBLOCK_INPUT;
1213 #ifndef SYSTEM_MALLOC
1215 /* Arranging to disable input signals while we're in malloc.
1217 This only works with GNU malloc. To help out systems which can't
1218 use GNU malloc, all the calls to malloc, realloc, and free
1219 elsewhere in the code should be inside a BLOCK_INPUT/UNBLOCK_INPUT
1220 pair; unfortunately, we have no idea what C library functions
1221 might call malloc, so we can't really protect them unless you're
1222 using GNU malloc. Fortunately, most of the major operating systems
1223 can use GNU malloc. */
1225 #ifndef SYNC_INPUT
1226 /* When using SYNC_INPUT, we don't call malloc from a signal handler, so
1227 there's no need to block input around malloc. */
1229 #ifndef DOUG_LEA_MALLOC
1230 extern void * (*__malloc_hook) (size_t, const void *);
1231 extern void * (*__realloc_hook) (void *, size_t, const void *);
1232 extern void (*__free_hook) (void *, const void *);
1233 /* Else declared in malloc.h, perhaps with an extra arg. */
1234 #endif /* DOUG_LEA_MALLOC */
1235 static void * (*old_malloc_hook) (size_t, const void *);
1236 static void * (*old_realloc_hook) (void *, size_t, const void*);
1237 static void (*old_free_hook) (void*, const void*);
1239 #ifdef DOUG_LEA_MALLOC
1240 # define BYTES_USED (mallinfo ().uordblks)
1241 #else
1242 # define BYTES_USED _bytes_used
1243 #endif
1245 #ifdef GC_MALLOC_CHECK
1246 static bool dont_register_blocks;
1247 #endif
1249 static size_t bytes_used_when_reconsidered;
1251 /* Value of _bytes_used, when spare_memory was freed. */
1253 static size_t bytes_used_when_full;
1255 /* This function is used as the hook for free to call. */
1257 static void
1258 emacs_blocked_free (void *ptr, const void *ptr2)
1260 BLOCK_INPUT_ALLOC;
1262 #ifdef GC_MALLOC_CHECK
1263 if (ptr)
1265 struct mem_node *m;
1267 m = mem_find (ptr);
1268 if (m == MEM_NIL || m->start != ptr)
1270 fprintf (stderr,
1271 "Freeing `%p' which wasn't allocated with malloc\n", ptr);
1272 abort ();
1274 else
1276 /* fprintf (stderr, "free %p...%p (%p)\n", m->start, m->end, ptr); */
1277 mem_delete (m);
1280 #endif /* GC_MALLOC_CHECK */
1282 __free_hook = old_free_hook;
1283 free (ptr);
1285 /* If we released our reserve (due to running out of memory),
1286 and we have a fair amount free once again,
1287 try to set aside another reserve in case we run out once more. */
1288 if (! NILP (Vmemory_full)
1289 /* Verify there is enough space that even with the malloc
1290 hysteresis this call won't run out again.
1291 The code here is correct as long as SPARE_MEMORY
1292 is substantially larger than the block size malloc uses. */
1293 && (bytes_used_when_full
1294 > ((bytes_used_when_reconsidered = BYTES_USED)
1295 + max (malloc_hysteresis, 4) * SPARE_MEMORY)))
1296 refill_memory_reserve ();
1298 __free_hook = emacs_blocked_free;
1299 UNBLOCK_INPUT_ALLOC;
1303 /* This function is the malloc hook that Emacs uses. */
1305 static void *
1306 emacs_blocked_malloc (size_t size, const void *ptr)
1308 void *value;
1310 BLOCK_INPUT_ALLOC;
1311 __malloc_hook = old_malloc_hook;
1312 #ifdef DOUG_LEA_MALLOC
1313 /* Segfaults on my system. --lorentey */
1314 /* mallopt (M_TOP_PAD, malloc_hysteresis * 4096); */
1315 #else
1316 __malloc_extra_blocks = malloc_hysteresis;
1317 #endif
1319 value = malloc (size);
1321 #ifdef GC_MALLOC_CHECK
1323 struct mem_node *m = mem_find (value);
1324 if (m != MEM_NIL)
1326 fprintf (stderr, "Malloc returned %p which is already in use\n",
1327 value);
1328 fprintf (stderr, "Region in use is %p...%p, %td bytes, type %d\n",
1329 m->start, m->end, (char *) m->end - (char *) m->start,
1330 m->type);
1331 abort ();
1334 if (!dont_register_blocks)
1336 mem_insert (value, (char *) value + max (1, size), allocated_mem_type);
1337 allocated_mem_type = MEM_TYPE_NON_LISP;
1340 #endif /* GC_MALLOC_CHECK */
1342 __malloc_hook = emacs_blocked_malloc;
1343 UNBLOCK_INPUT_ALLOC;
1345 /* fprintf (stderr, "%p malloc\n", value); */
1346 return value;
1350 /* This function is the realloc hook that Emacs uses. */
1352 static void *
1353 emacs_blocked_realloc (void *ptr, size_t size, const void *ptr2)
1355 void *value;
1357 BLOCK_INPUT_ALLOC;
1358 __realloc_hook = old_realloc_hook;
1360 #ifdef GC_MALLOC_CHECK
1361 if (ptr)
1363 struct mem_node *m = mem_find (ptr);
1364 if (m == MEM_NIL || m->start != ptr)
1366 fprintf (stderr,
1367 "Realloc of %p which wasn't allocated with malloc\n",
1368 ptr);
1369 abort ();
1372 mem_delete (m);
1375 /* fprintf (stderr, "%p -> realloc\n", ptr); */
1377 /* Prevent malloc from registering blocks. */
1378 dont_register_blocks = 1;
1379 #endif /* GC_MALLOC_CHECK */
1381 value = realloc (ptr, size);
1383 #ifdef GC_MALLOC_CHECK
1384 dont_register_blocks = 0;
1387 struct mem_node *m = mem_find (value);
1388 if (m != MEM_NIL)
1390 fprintf (stderr, "Realloc returns memory that is already in use\n");
1391 abort ();
1394 /* Can't handle zero size regions in the red-black tree. */
1395 mem_insert (value, (char *) value + max (size, 1), MEM_TYPE_NON_LISP);
1398 /* fprintf (stderr, "%p <- realloc\n", value); */
1399 #endif /* GC_MALLOC_CHECK */
1401 __realloc_hook = emacs_blocked_realloc;
1402 UNBLOCK_INPUT_ALLOC;
1404 return value;
1408 #ifdef HAVE_PTHREAD
1409 /* Called from Fdump_emacs so that when the dumped Emacs starts, it has a
1410 normal malloc. Some thread implementations need this as they call
1411 malloc before main. The pthread_self call in BLOCK_INPUT_ALLOC then
1412 calls malloc because it is the first call, and we have an endless loop. */
1414 void
1415 reset_malloc_hooks (void)
1417 __free_hook = old_free_hook;
1418 __malloc_hook = old_malloc_hook;
1419 __realloc_hook = old_realloc_hook;
1421 #endif /* HAVE_PTHREAD */
1424 /* Called from main to set up malloc to use our hooks. */
1426 void
1427 uninterrupt_malloc (void)
1429 #ifdef HAVE_PTHREAD
1430 #ifdef DOUG_LEA_MALLOC
1431 pthread_mutexattr_t attr;
1433 /* GLIBC has a faster way to do this, but let's keep it portable.
1434 This is according to the Single UNIX Specification. */
1435 pthread_mutexattr_init (&attr);
1436 pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
1437 pthread_mutex_init (&alloc_mutex, &attr);
1438 #else /* !DOUG_LEA_MALLOC */
1439 /* Some systems such as Solaris 2.6 don't have a recursive mutex,
1440 and the bundled gmalloc.c doesn't require it. */
1441 pthread_mutex_init (&alloc_mutex, NULL);
1442 #endif /* !DOUG_LEA_MALLOC */
1443 #endif /* HAVE_PTHREAD */
1445 if (__free_hook != emacs_blocked_free)
1446 old_free_hook = __free_hook;
1447 __free_hook = emacs_blocked_free;
1449 if (__malloc_hook != emacs_blocked_malloc)
1450 old_malloc_hook = __malloc_hook;
1451 __malloc_hook = emacs_blocked_malloc;
1453 if (__realloc_hook != emacs_blocked_realloc)
1454 old_realloc_hook = __realloc_hook;
1455 __realloc_hook = emacs_blocked_realloc;
1458 #endif /* not SYNC_INPUT */
1459 #endif /* not SYSTEM_MALLOC */
1463 /***********************************************************************
1464 Interval Allocation
1465 ***********************************************************************/
1467 /* Number of intervals allocated in an interval_block structure.
1468 The 1020 is 1024 minus malloc overhead. */
1470 #define INTERVAL_BLOCK_SIZE \
1471 ((1020 - sizeof (struct interval_block *)) / sizeof (struct interval))
1473 /* Intervals are allocated in chunks in form of an interval_block
1474 structure. */
1476 struct interval_block
1478 /* Place `intervals' first, to preserve alignment. */
1479 struct interval intervals[INTERVAL_BLOCK_SIZE];
1480 struct interval_block *next;
1483 /* Current interval block. Its `next' pointer points to older
1484 blocks. */
1486 static struct interval_block *interval_block;
1488 /* Index in interval_block above of the next unused interval
1489 structure. */
1491 static int interval_block_index = INTERVAL_BLOCK_SIZE;
1493 /* Number of free and live intervals. */
1495 static EMACS_INT total_free_intervals, total_intervals;
1497 /* List of free intervals. */
1499 static INTERVAL interval_free_list;
1501 /* Return a new interval. */
1503 INTERVAL
1504 make_interval (void)
1506 INTERVAL val;
1508 /* eassert (!handling_signal); */
1510 MALLOC_BLOCK_INPUT;
1512 if (interval_free_list)
1514 val = interval_free_list;
1515 interval_free_list = INTERVAL_PARENT (interval_free_list);
1517 else
1519 if (interval_block_index == INTERVAL_BLOCK_SIZE)
1521 struct interval_block *newi
1522 = lisp_malloc (sizeof *newi, MEM_TYPE_NON_LISP);
1524 newi->next = interval_block;
1525 interval_block = newi;
1526 interval_block_index = 0;
1527 total_free_intervals += INTERVAL_BLOCK_SIZE;
1529 val = &interval_block->intervals[interval_block_index++];
1532 MALLOC_UNBLOCK_INPUT;
1534 consing_since_gc += sizeof (struct interval);
1535 intervals_consed++;
1536 total_free_intervals--;
1537 RESET_INTERVAL (val);
1538 val->gcmarkbit = 0;
1539 return val;
1543 /* Mark Lisp objects in interval I. */
1545 static void
1546 mark_interval (register INTERVAL i, Lisp_Object dummy)
1548 /* Intervals should never be shared. So, if extra internal checking is
1549 enabled, GC aborts if it seems to have visited an interval twice. */
1550 eassert (!i->gcmarkbit);
1551 i->gcmarkbit = 1;
1552 mark_object (i->plist);
1555 /* Mark the interval tree rooted in I. */
1557 #define MARK_INTERVAL_TREE(i) \
1558 do { \
1559 if (i && !i->gcmarkbit) \
1560 traverse_intervals_noorder (i, mark_interval, Qnil); \
1561 } while (0)
1563 /***********************************************************************
1564 String Allocation
1565 ***********************************************************************/
1567 /* Lisp_Strings are allocated in string_block structures. When a new
1568 string_block is allocated, all the Lisp_Strings it contains are
1569 added to a free-list string_free_list. When a new Lisp_String is
1570 needed, it is taken from that list. During the sweep phase of GC,
1571 string_blocks that are entirely free are freed, except two which
1572 we keep.
1574 String data is allocated from sblock structures. Strings larger
1575 than LARGE_STRING_BYTES, get their own sblock, data for smaller
1576 strings is sub-allocated out of sblocks of size SBLOCK_SIZE.
1578 Sblocks consist internally of sdata structures, one for each
1579 Lisp_String. The sdata structure points to the Lisp_String it
1580 belongs to. The Lisp_String points back to the `u.data' member of
1581 its sdata structure.
1583 When a Lisp_String is freed during GC, it is put back on
1584 string_free_list, and its `data' member and its sdata's `string'
1585 pointer is set to null. The size of the string is recorded in the
1586 `u.nbytes' member of the sdata. So, sdata structures that are no
1587 longer used, can be easily recognized, and it's easy to compact the
1588 sblocks of small strings which we do in compact_small_strings. */
1590 /* Size in bytes of an sblock structure used for small strings. This
1591 is 8192 minus malloc overhead. */
1593 #define SBLOCK_SIZE 8188
1595 /* Strings larger than this are considered large strings. String data
1596 for large strings is allocated from individual sblocks. */
1598 #define LARGE_STRING_BYTES 1024
1600 /* Structure describing string memory sub-allocated from an sblock.
1601 This is where the contents of Lisp strings are stored. */
1603 struct sdata
1605 /* Back-pointer to the string this sdata belongs to. If null, this
1606 structure is free, and the NBYTES member of the union below
1607 contains the string's byte size (the same value that STRING_BYTES
1608 would return if STRING were non-null). If non-null, STRING_BYTES
1609 (STRING) is the size of the data, and DATA contains the string's
1610 contents. */
1611 struct Lisp_String *string;
1613 #ifdef GC_CHECK_STRING_BYTES
1615 ptrdiff_t nbytes;
1616 unsigned char data[1];
1618 #define SDATA_NBYTES(S) (S)->nbytes
1619 #define SDATA_DATA(S) (S)->data
1620 #define SDATA_SELECTOR(member) member
1622 #else /* not GC_CHECK_STRING_BYTES */
1624 union
1626 /* When STRING is non-null. */
1627 unsigned char data[1];
1629 /* When STRING is null. */
1630 ptrdiff_t nbytes;
1631 } u;
1633 #define SDATA_NBYTES(S) (S)->u.nbytes
1634 #define SDATA_DATA(S) (S)->u.data
1635 #define SDATA_SELECTOR(member) u.member
1637 #endif /* not GC_CHECK_STRING_BYTES */
1639 #define SDATA_DATA_OFFSET offsetof (struct sdata, SDATA_SELECTOR (data))
1643 /* Structure describing a block of memory which is sub-allocated to
1644 obtain string data memory for strings. Blocks for small strings
1645 are of fixed size SBLOCK_SIZE. Blocks for large strings are made
1646 as large as needed. */
1648 struct sblock
1650 /* Next in list. */
1651 struct sblock *next;
1653 /* Pointer to the next free sdata block. This points past the end
1654 of the sblock if there isn't any space left in this block. */
1655 struct sdata *next_free;
1657 /* Start of data. */
1658 struct sdata first_data;
1661 /* Number of Lisp strings in a string_block structure. The 1020 is
1662 1024 minus malloc overhead. */
1664 #define STRING_BLOCK_SIZE \
1665 ((1020 - sizeof (struct string_block *)) / sizeof (struct Lisp_String))
1667 /* Structure describing a block from which Lisp_String structures
1668 are allocated. */
1670 struct string_block
1672 /* Place `strings' first, to preserve alignment. */
1673 struct Lisp_String strings[STRING_BLOCK_SIZE];
1674 struct string_block *next;
1677 /* Head and tail of the list of sblock structures holding Lisp string
1678 data. We always allocate from current_sblock. The NEXT pointers
1679 in the sblock structures go from oldest_sblock to current_sblock. */
1681 static struct sblock *oldest_sblock, *current_sblock;
1683 /* List of sblocks for large strings. */
1685 static struct sblock *large_sblocks;
1687 /* List of string_block structures. */
1689 static struct string_block *string_blocks;
1691 /* Free-list of Lisp_Strings. */
1693 static struct Lisp_String *string_free_list;
1695 /* Number of live and free Lisp_Strings. */
1697 static EMACS_INT total_strings, total_free_strings;
1699 /* Number of bytes used by live strings. */
1701 static EMACS_INT total_string_bytes;
1703 /* Given a pointer to a Lisp_String S which is on the free-list
1704 string_free_list, return a pointer to its successor in the
1705 free-list. */
1707 #define NEXT_FREE_LISP_STRING(S) (*(struct Lisp_String **) (S))
1709 /* Return a pointer to the sdata structure belonging to Lisp string S.
1710 S must be live, i.e. S->data must not be null. S->data is actually
1711 a pointer to the `u.data' member of its sdata structure; the
1712 structure starts at a constant offset in front of that. */
1714 #define SDATA_OF_STRING(S) ((struct sdata *) ((S)->data - SDATA_DATA_OFFSET))
1717 #ifdef GC_CHECK_STRING_OVERRUN
1719 /* We check for overrun in string data blocks by appending a small
1720 "cookie" after each allocated string data block, and check for the
1721 presence of this cookie during GC. */
1723 #define GC_STRING_OVERRUN_COOKIE_SIZE 4
1724 static char const string_overrun_cookie[GC_STRING_OVERRUN_COOKIE_SIZE] =
1725 { '\xde', '\xad', '\xbe', '\xef' };
1727 #else
1728 #define GC_STRING_OVERRUN_COOKIE_SIZE 0
1729 #endif
1731 /* Value is the size of an sdata structure large enough to hold NBYTES
1732 bytes of string data. The value returned includes a terminating
1733 NUL byte, the size of the sdata structure, and padding. */
1735 #ifdef GC_CHECK_STRING_BYTES
1737 #define SDATA_SIZE(NBYTES) \
1738 ((SDATA_DATA_OFFSET \
1739 + (NBYTES) + 1 \
1740 + sizeof (ptrdiff_t) - 1) \
1741 & ~(sizeof (ptrdiff_t) - 1))
1743 #else /* not GC_CHECK_STRING_BYTES */
1745 /* The 'max' reserves space for the nbytes union member even when NBYTES + 1 is
1746 less than the size of that member. The 'max' is not needed when
1747 SDATA_DATA_OFFSET is a multiple of sizeof (ptrdiff_t), because then the
1748 alignment code reserves enough space. */
1750 #define SDATA_SIZE(NBYTES) \
1751 ((SDATA_DATA_OFFSET \
1752 + (SDATA_DATA_OFFSET % sizeof (ptrdiff_t) == 0 \
1753 ? NBYTES \
1754 : max (NBYTES, sizeof (ptrdiff_t) - 1)) \
1755 + 1 \
1756 + sizeof (ptrdiff_t) - 1) \
1757 & ~(sizeof (ptrdiff_t) - 1))
1759 #endif /* not GC_CHECK_STRING_BYTES */
1761 /* Extra bytes to allocate for each string. */
1763 #define GC_STRING_EXTRA (GC_STRING_OVERRUN_COOKIE_SIZE)
1765 /* Exact bound on the number of bytes in a string, not counting the
1766 terminating null. A string cannot contain more bytes than
1767 STRING_BYTES_BOUND, nor can it be so long that the size_t
1768 arithmetic in allocate_string_data would overflow while it is
1769 calculating a value to be passed to malloc. */
1770 static ptrdiff_t const STRING_BYTES_MAX =
1771 min (STRING_BYTES_BOUND,
1772 ((SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD
1773 - GC_STRING_EXTRA
1774 - offsetof (struct sblock, first_data)
1775 - SDATA_DATA_OFFSET)
1776 & ~(sizeof (EMACS_INT) - 1)));
1778 /* Initialize string allocation. Called from init_alloc_once. */
1780 static void
1781 init_strings (void)
1783 empty_unibyte_string = make_pure_string ("", 0, 0, 0);
1784 empty_multibyte_string = make_pure_string ("", 0, 0, 1);
1788 #ifdef GC_CHECK_STRING_BYTES
1790 static int check_string_bytes_count;
1792 /* Like STRING_BYTES, but with debugging check. Can be
1793 called during GC, so pay attention to the mark bit. */
1795 ptrdiff_t
1796 string_bytes (struct Lisp_String *s)
1798 ptrdiff_t nbytes =
1799 (s->size_byte < 0 ? s->size & ~ARRAY_MARK_FLAG : s->size_byte);
1801 if (!PURE_POINTER_P (s)
1802 && s->data
1803 && nbytes != SDATA_NBYTES (SDATA_OF_STRING (s)))
1804 abort ();
1805 return nbytes;
1808 /* Check validity of Lisp strings' string_bytes member in B. */
1810 static void
1811 check_sblock (struct sblock *b)
1813 struct sdata *from, *end, *from_end;
1815 end = b->next_free;
1817 for (from = &b->first_data; from < end; from = from_end)
1819 /* Compute the next FROM here because copying below may
1820 overwrite data we need to compute it. */
1821 ptrdiff_t nbytes;
1823 /* Check that the string size recorded in the string is the
1824 same as the one recorded in the sdata structure. */
1825 nbytes = SDATA_SIZE (from->string ? string_bytes (from->string)
1826 : SDATA_NBYTES (from));
1827 from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
1832 /* Check validity of Lisp strings' string_bytes member. ALL_P
1833 means check all strings, otherwise check only most
1834 recently allocated strings. Used for hunting a bug. */
1836 static void
1837 check_string_bytes (bool all_p)
1839 if (all_p)
1841 struct sblock *b;
1843 for (b = large_sblocks; b; b = b->next)
1845 struct Lisp_String *s = b->first_data.string;
1846 if (s)
1847 string_bytes (s);
1850 for (b = oldest_sblock; b; b = b->next)
1851 check_sblock (b);
1853 else if (current_sblock)
1854 check_sblock (current_sblock);
1857 #else /* not GC_CHECK_STRING_BYTES */
1859 #define check_string_bytes(all) ((void) 0)
1861 #endif /* GC_CHECK_STRING_BYTES */
1863 #ifdef GC_CHECK_STRING_FREE_LIST
1865 /* Walk through the string free list looking for bogus next pointers.
1866 This may catch buffer overrun from a previous string. */
1868 static void
1869 check_string_free_list (void)
1871 struct Lisp_String *s;
1873 /* Pop a Lisp_String off the free-list. */
1874 s = string_free_list;
1875 while (s != NULL)
1877 if ((uintptr_t) s < 1024)
1878 abort ();
1879 s = NEXT_FREE_LISP_STRING (s);
1882 #else
1883 #define check_string_free_list()
1884 #endif
1886 /* Return a new Lisp_String. */
1888 static struct Lisp_String *
1889 allocate_string (void)
1891 struct Lisp_String *s;
1893 /* eassert (!handling_signal); */
1895 MALLOC_BLOCK_INPUT;
1897 /* If the free-list is empty, allocate a new string_block, and
1898 add all the Lisp_Strings in it to the free-list. */
1899 if (string_free_list == NULL)
1901 struct string_block *b = lisp_malloc (sizeof *b, MEM_TYPE_STRING);
1902 int i;
1904 b->next = string_blocks;
1905 string_blocks = b;
1907 for (i = STRING_BLOCK_SIZE - 1; i >= 0; --i)
1909 s = b->strings + i;
1910 /* Every string on a free list should have NULL data pointer. */
1911 s->data = NULL;
1912 NEXT_FREE_LISP_STRING (s) = string_free_list;
1913 string_free_list = s;
1916 total_free_strings += STRING_BLOCK_SIZE;
1919 check_string_free_list ();
1921 /* Pop a Lisp_String off the free-list. */
1922 s = string_free_list;
1923 string_free_list = NEXT_FREE_LISP_STRING (s);
1925 MALLOC_UNBLOCK_INPUT;
1927 --total_free_strings;
1928 ++total_strings;
1929 ++strings_consed;
1930 consing_since_gc += sizeof *s;
1932 #ifdef GC_CHECK_STRING_BYTES
1933 if (!noninteractive)
1935 if (++check_string_bytes_count == 200)
1937 check_string_bytes_count = 0;
1938 check_string_bytes (1);
1940 else
1941 check_string_bytes (0);
1943 #endif /* GC_CHECK_STRING_BYTES */
1945 return s;
1949 /* Set up Lisp_String S for holding NCHARS characters, NBYTES bytes,
1950 plus a NUL byte at the end. Allocate an sdata structure for S, and
1951 set S->data to its `u.data' member. Store a NUL byte at the end of
1952 S->data. Set S->size to NCHARS and S->size_byte to NBYTES. Free
1953 S->data if it was initially non-null. */
1955 void
1956 allocate_string_data (struct Lisp_String *s,
1957 EMACS_INT nchars, EMACS_INT nbytes)
1959 struct sdata *data, *old_data;
1960 struct sblock *b;
1961 ptrdiff_t needed, old_nbytes;
1963 if (STRING_BYTES_MAX < nbytes)
1964 string_overflow ();
1966 /* Determine the number of bytes needed to store NBYTES bytes
1967 of string data. */
1968 needed = SDATA_SIZE (nbytes);
1969 if (s->data)
1971 old_data = SDATA_OF_STRING (s);
1972 old_nbytes = STRING_BYTES (s);
1974 else
1975 old_data = NULL;
1977 MALLOC_BLOCK_INPUT;
1979 if (nbytes > LARGE_STRING_BYTES)
1981 size_t size = offsetof (struct sblock, first_data) + needed;
1983 #ifdef DOUG_LEA_MALLOC
1984 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1985 because mapped region contents are not preserved in
1986 a dumped Emacs.
1988 In case you think of allowing it in a dumped Emacs at the
1989 cost of not being able to re-dump, there's another reason:
1990 mmap'ed data typically have an address towards the top of the
1991 address space, which won't fit into an EMACS_INT (at least on
1992 32-bit systems with the current tagging scheme). --fx */
1993 mallopt (M_MMAP_MAX, 0);
1994 #endif
1996 b = lisp_malloc (size + GC_STRING_EXTRA, MEM_TYPE_NON_LISP);
1998 #ifdef DOUG_LEA_MALLOC
1999 /* Back to a reasonable maximum of mmap'ed areas. */
2000 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
2001 #endif
2003 b->next_free = &b->first_data;
2004 b->first_data.string = NULL;
2005 b->next = large_sblocks;
2006 large_sblocks = b;
2008 else if (current_sblock == NULL
2009 || (((char *) current_sblock + SBLOCK_SIZE
2010 - (char *) current_sblock->next_free)
2011 < (needed + GC_STRING_EXTRA)))
2013 /* Not enough room in the current sblock. */
2014 b = lisp_malloc (SBLOCK_SIZE, MEM_TYPE_NON_LISP);
2015 b->next_free = &b->first_data;
2016 b->first_data.string = NULL;
2017 b->next = NULL;
2019 if (current_sblock)
2020 current_sblock->next = b;
2021 else
2022 oldest_sblock = b;
2023 current_sblock = b;
2025 else
2026 b = current_sblock;
2028 data = b->next_free;
2029 b->next_free = (struct sdata *) ((char *) data + needed + GC_STRING_EXTRA);
2031 MALLOC_UNBLOCK_INPUT;
2033 data->string = s;
2034 s->data = SDATA_DATA (data);
2035 #ifdef GC_CHECK_STRING_BYTES
2036 SDATA_NBYTES (data) = nbytes;
2037 #endif
2038 s->size = nchars;
2039 s->size_byte = nbytes;
2040 s->data[nbytes] = '\0';
2041 #ifdef GC_CHECK_STRING_OVERRUN
2042 memcpy ((char *) data + needed, string_overrun_cookie,
2043 GC_STRING_OVERRUN_COOKIE_SIZE);
2044 #endif
2046 /* Note that Faset may call to this function when S has already data
2047 assigned. In this case, mark data as free by setting it's string
2048 back-pointer to null, and record the size of the data in it. */
2049 if (old_data)
2051 SDATA_NBYTES (old_data) = old_nbytes;
2052 old_data->string = NULL;
2055 consing_since_gc += needed;
2059 /* Sweep and compact strings. */
2061 static void
2062 sweep_strings (void)
2064 struct string_block *b, *next;
2065 struct string_block *live_blocks = NULL;
2067 string_free_list = NULL;
2068 total_strings = total_free_strings = 0;
2069 total_string_bytes = 0;
2071 /* Scan strings_blocks, free Lisp_Strings that aren't marked. */
2072 for (b = string_blocks; b; b = next)
2074 int i, nfree = 0;
2075 struct Lisp_String *free_list_before = string_free_list;
2077 next = b->next;
2079 for (i = 0; i < STRING_BLOCK_SIZE; ++i)
2081 struct Lisp_String *s = b->strings + i;
2083 if (s->data)
2085 /* String was not on free-list before. */
2086 if (STRING_MARKED_P (s))
2088 /* String is live; unmark it and its intervals. */
2089 UNMARK_STRING (s);
2091 /* Do not use string_(set|get)_intervals here. */
2092 s->intervals = balance_intervals (s->intervals);
2094 ++total_strings;
2095 total_string_bytes += STRING_BYTES (s);
2097 else
2099 /* String is dead. Put it on the free-list. */
2100 struct sdata *data = SDATA_OF_STRING (s);
2102 /* Save the size of S in its sdata so that we know
2103 how large that is. Reset the sdata's string
2104 back-pointer so that we know it's free. */
2105 #ifdef GC_CHECK_STRING_BYTES
2106 if (string_bytes (s) != SDATA_NBYTES (data))
2107 abort ();
2108 #else
2109 data->u.nbytes = STRING_BYTES (s);
2110 #endif
2111 data->string = NULL;
2113 /* Reset the strings's `data' member so that we
2114 know it's free. */
2115 s->data = NULL;
2117 /* Put the string on the free-list. */
2118 NEXT_FREE_LISP_STRING (s) = string_free_list;
2119 string_free_list = s;
2120 ++nfree;
2123 else
2125 /* S was on the free-list before. Put it there again. */
2126 NEXT_FREE_LISP_STRING (s) = string_free_list;
2127 string_free_list = s;
2128 ++nfree;
2132 /* Free blocks that contain free Lisp_Strings only, except
2133 the first two of them. */
2134 if (nfree == STRING_BLOCK_SIZE
2135 && total_free_strings > STRING_BLOCK_SIZE)
2137 lisp_free (b);
2138 string_free_list = free_list_before;
2140 else
2142 total_free_strings += nfree;
2143 b->next = live_blocks;
2144 live_blocks = b;
2148 check_string_free_list ();
2150 string_blocks = live_blocks;
2151 free_large_strings ();
2152 compact_small_strings ();
2154 check_string_free_list ();
2158 /* Free dead large strings. */
2160 static void
2161 free_large_strings (void)
2163 struct sblock *b, *next;
2164 struct sblock *live_blocks = NULL;
2166 for (b = large_sblocks; b; b = next)
2168 next = b->next;
2170 if (b->first_data.string == NULL)
2171 lisp_free (b);
2172 else
2174 b->next = live_blocks;
2175 live_blocks = b;
2179 large_sblocks = live_blocks;
2183 /* Compact data of small strings. Free sblocks that don't contain
2184 data of live strings after compaction. */
2186 static void
2187 compact_small_strings (void)
2189 struct sblock *b, *tb, *next;
2190 struct sdata *from, *to, *end, *tb_end;
2191 struct sdata *to_end, *from_end;
2193 /* TB is the sblock we copy to, TO is the sdata within TB we copy
2194 to, and TB_END is the end of TB. */
2195 tb = oldest_sblock;
2196 tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
2197 to = &tb->first_data;
2199 /* Step through the blocks from the oldest to the youngest. We
2200 expect that old blocks will stabilize over time, so that less
2201 copying will happen this way. */
2202 for (b = oldest_sblock; b; b = b->next)
2204 end = b->next_free;
2205 eassert ((char *) end <= (char *) b + SBLOCK_SIZE);
2207 for (from = &b->first_data; from < end; from = from_end)
2209 /* Compute the next FROM here because copying below may
2210 overwrite data we need to compute it. */
2211 ptrdiff_t nbytes;
2212 struct Lisp_String *s = from->string;
2214 #ifdef GC_CHECK_STRING_BYTES
2215 /* Check that the string size recorded in the string is the
2216 same as the one recorded in the sdata structure. */
2217 if (s && string_bytes (s) != SDATA_NBYTES (from))
2218 abort ();
2219 #endif /* GC_CHECK_STRING_BYTES */
2221 nbytes = s ? STRING_BYTES (s) : SDATA_NBYTES (from);
2222 eassert (nbytes <= LARGE_STRING_BYTES);
2224 nbytes = SDATA_SIZE (nbytes);
2225 from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
2227 #ifdef GC_CHECK_STRING_OVERRUN
2228 if (memcmp (string_overrun_cookie,
2229 (char *) from_end - GC_STRING_OVERRUN_COOKIE_SIZE,
2230 GC_STRING_OVERRUN_COOKIE_SIZE))
2231 abort ();
2232 #endif
2234 /* Non-NULL S means it's alive. Copy its data. */
2235 if (s)
2237 /* If TB is full, proceed with the next sblock. */
2238 to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
2239 if (to_end > tb_end)
2241 tb->next_free = to;
2242 tb = tb->next;
2243 tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
2244 to = &tb->first_data;
2245 to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
2248 /* Copy, and update the string's `data' pointer. */
2249 if (from != to)
2251 eassert (tb != b || to < from);
2252 memmove (to, from, nbytes + GC_STRING_EXTRA);
2253 to->string->data = SDATA_DATA (to);
2256 /* Advance past the sdata we copied to. */
2257 to = to_end;
2262 /* The rest of the sblocks following TB don't contain live data, so
2263 we can free them. */
2264 for (b = tb->next; b; b = next)
2266 next = b->next;
2267 lisp_free (b);
2270 tb->next_free = to;
2271 tb->next = NULL;
2272 current_sblock = tb;
2275 void
2276 string_overflow (void)
2278 error ("Maximum string size exceeded");
2281 DEFUN ("make-string", Fmake_string, Smake_string, 2, 2, 0,
2282 doc: /* Return a newly created string of length LENGTH, with INIT in each element.
2283 LENGTH must be an integer.
2284 INIT must be an integer that represents a character. */)
2285 (Lisp_Object length, Lisp_Object init)
2287 register Lisp_Object val;
2288 register unsigned char *p, *end;
2289 int c;
2290 EMACS_INT nbytes;
2292 CHECK_NATNUM (length);
2293 CHECK_CHARACTER (init);
2295 c = XFASTINT (init);
2296 if (ASCII_CHAR_P (c))
2298 nbytes = XINT (length);
2299 val = make_uninit_string (nbytes);
2300 p = SDATA (val);
2301 end = p + SCHARS (val);
2302 while (p != end)
2303 *p++ = c;
2305 else
2307 unsigned char str[MAX_MULTIBYTE_LENGTH];
2308 int len = CHAR_STRING (c, str);
2309 EMACS_INT string_len = XINT (length);
2311 if (string_len > STRING_BYTES_MAX / len)
2312 string_overflow ();
2313 nbytes = len * string_len;
2314 val = make_uninit_multibyte_string (string_len, nbytes);
2315 p = SDATA (val);
2316 end = p + nbytes;
2317 while (p != end)
2319 memcpy (p, str, len);
2320 p += len;
2324 *p = 0;
2325 return val;
2329 DEFUN ("make-bool-vector", Fmake_bool_vector, Smake_bool_vector, 2, 2, 0,
2330 doc: /* Return a new bool-vector of length LENGTH, using INIT for each element.
2331 LENGTH must be a number. INIT matters only in whether it is t or nil. */)
2332 (Lisp_Object length, Lisp_Object init)
2334 register Lisp_Object val;
2335 struct Lisp_Bool_Vector *p;
2336 ptrdiff_t length_in_chars;
2337 EMACS_INT length_in_elts;
2338 int bits_per_value;
2339 int extra_bool_elts = ((bool_header_size - header_size + word_size - 1)
2340 / word_size);
2342 CHECK_NATNUM (length);
2344 bits_per_value = sizeof (EMACS_INT) * BOOL_VECTOR_BITS_PER_CHAR;
2346 length_in_elts = (XFASTINT (length) + bits_per_value - 1) / bits_per_value;
2348 val = Fmake_vector (make_number (length_in_elts + extra_bool_elts), Qnil);
2350 /* No Lisp_Object to trace in there. */
2351 XSETPVECTYPESIZE (XVECTOR (val), PVEC_BOOL_VECTOR, 0);
2353 p = XBOOL_VECTOR (val);
2354 p->size = XFASTINT (length);
2356 length_in_chars = ((XFASTINT (length) + BOOL_VECTOR_BITS_PER_CHAR - 1)
2357 / BOOL_VECTOR_BITS_PER_CHAR);
2358 if (length_in_chars)
2360 memset (p->data, ! NILP (init) ? -1 : 0, length_in_chars);
2362 /* Clear any extraneous bits in the last byte. */
2363 p->data[length_in_chars - 1]
2364 &= (1 << ((XFASTINT (length) - 1) % BOOL_VECTOR_BITS_PER_CHAR + 1)) - 1;
2367 return val;
2371 /* Make a string from NBYTES bytes at CONTENTS, and compute the number
2372 of characters from the contents. This string may be unibyte or
2373 multibyte, depending on the contents. */
2375 Lisp_Object
2376 make_string (const char *contents, ptrdiff_t nbytes)
2378 register Lisp_Object val;
2379 ptrdiff_t nchars, multibyte_nbytes;
2381 parse_str_as_multibyte ((const unsigned char *) contents, nbytes,
2382 &nchars, &multibyte_nbytes);
2383 if (nbytes == nchars || nbytes != multibyte_nbytes)
2384 /* CONTENTS contains no multibyte sequences or contains an invalid
2385 multibyte sequence. We must make unibyte string. */
2386 val = make_unibyte_string (contents, nbytes);
2387 else
2388 val = make_multibyte_string (contents, nchars, nbytes);
2389 return val;
2393 /* Make an unibyte string from LENGTH bytes at CONTENTS. */
2395 Lisp_Object
2396 make_unibyte_string (const char *contents, ptrdiff_t length)
2398 register Lisp_Object val;
2399 val = make_uninit_string (length);
2400 memcpy (SDATA (val), contents, length);
2401 return val;
2405 /* Make a multibyte string from NCHARS characters occupying NBYTES
2406 bytes at CONTENTS. */
2408 Lisp_Object
2409 make_multibyte_string (const char *contents,
2410 ptrdiff_t nchars, ptrdiff_t nbytes)
2412 register Lisp_Object val;
2413 val = make_uninit_multibyte_string (nchars, nbytes);
2414 memcpy (SDATA (val), contents, nbytes);
2415 return val;
2419 /* Make a string from NCHARS characters occupying NBYTES bytes at
2420 CONTENTS. It is a multibyte string if NBYTES != NCHARS. */
2422 Lisp_Object
2423 make_string_from_bytes (const char *contents,
2424 ptrdiff_t nchars, ptrdiff_t nbytes)
2426 register Lisp_Object val;
2427 val = make_uninit_multibyte_string (nchars, nbytes);
2428 memcpy (SDATA (val), contents, nbytes);
2429 if (SBYTES (val) == SCHARS (val))
2430 STRING_SET_UNIBYTE (val);
2431 return val;
2435 /* Make a string from NCHARS characters occupying NBYTES bytes at
2436 CONTENTS. The argument MULTIBYTE controls whether to label the
2437 string as multibyte. If NCHARS is negative, it counts the number of
2438 characters by itself. */
2440 Lisp_Object
2441 make_specified_string (const char *contents,
2442 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
2444 Lisp_Object val;
2446 if (nchars < 0)
2448 if (multibyte)
2449 nchars = multibyte_chars_in_text ((const unsigned char *) contents,
2450 nbytes);
2451 else
2452 nchars = nbytes;
2454 val = make_uninit_multibyte_string (nchars, nbytes);
2455 memcpy (SDATA (val), contents, nbytes);
2456 if (!multibyte)
2457 STRING_SET_UNIBYTE (val);
2458 return val;
2462 /* Return an unibyte Lisp_String set up to hold LENGTH characters
2463 occupying LENGTH bytes. */
2465 Lisp_Object
2466 make_uninit_string (EMACS_INT length)
2468 Lisp_Object val;
2470 if (!length)
2471 return empty_unibyte_string;
2472 val = make_uninit_multibyte_string (length, length);
2473 STRING_SET_UNIBYTE (val);
2474 return val;
2478 /* Return a multibyte Lisp_String set up to hold NCHARS characters
2479 which occupy NBYTES bytes. */
2481 Lisp_Object
2482 make_uninit_multibyte_string (EMACS_INT nchars, EMACS_INT nbytes)
2484 Lisp_Object string;
2485 struct Lisp_String *s;
2487 if (nchars < 0)
2488 abort ();
2489 if (!nbytes)
2490 return empty_multibyte_string;
2492 s = allocate_string ();
2493 s->intervals = NULL;
2494 allocate_string_data (s, nchars, nbytes);
2495 XSETSTRING (string, s);
2496 string_chars_consed += nbytes;
2497 return string;
2500 /* Print arguments to BUF according to a FORMAT, then return
2501 a Lisp_String initialized with the data from BUF. */
2503 Lisp_Object
2504 make_formatted_string (char *buf, const char *format, ...)
2506 va_list ap;
2507 int length;
2509 va_start (ap, format);
2510 length = vsprintf (buf, format, ap);
2511 va_end (ap);
2512 return make_string (buf, length);
2516 /***********************************************************************
2517 Float Allocation
2518 ***********************************************************************/
2520 /* We store float cells inside of float_blocks, allocating a new
2521 float_block with malloc whenever necessary. Float cells reclaimed
2522 by GC are put on a free list to be reallocated before allocating
2523 any new float cells from the latest float_block. */
2525 #define FLOAT_BLOCK_SIZE \
2526 (((BLOCK_BYTES - sizeof (struct float_block *) \
2527 /* The compiler might add padding at the end. */ \
2528 - (sizeof (struct Lisp_Float) - sizeof (int))) * CHAR_BIT) \
2529 / (sizeof (struct Lisp_Float) * CHAR_BIT + 1))
2531 #define GETMARKBIT(block,n) \
2532 (((block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2533 >> ((n) % (sizeof (int) * CHAR_BIT))) \
2534 & 1)
2536 #define SETMARKBIT(block,n) \
2537 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2538 |= 1 << ((n) % (sizeof (int) * CHAR_BIT))
2540 #define UNSETMARKBIT(block,n) \
2541 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2542 &= ~(1 << ((n) % (sizeof (int) * CHAR_BIT)))
2544 #define FLOAT_BLOCK(fptr) \
2545 ((struct float_block *) (((uintptr_t) (fptr)) & ~(BLOCK_ALIGN - 1)))
2547 #define FLOAT_INDEX(fptr) \
2548 ((((uintptr_t) (fptr)) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Float))
2550 struct float_block
2552 /* Place `floats' at the beginning, to ease up FLOAT_INDEX's job. */
2553 struct Lisp_Float floats[FLOAT_BLOCK_SIZE];
2554 int gcmarkbits[1 + FLOAT_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2555 struct float_block *next;
2558 #define FLOAT_MARKED_P(fptr) \
2559 GETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2561 #define FLOAT_MARK(fptr) \
2562 SETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2564 #define FLOAT_UNMARK(fptr) \
2565 UNSETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2567 /* Current float_block. */
2569 static struct float_block *float_block;
2571 /* Index of first unused Lisp_Float in the current float_block. */
2573 static int float_block_index = FLOAT_BLOCK_SIZE;
2575 /* Free-list of Lisp_Floats. */
2577 static struct Lisp_Float *float_free_list;
2579 /* Return a new float object with value FLOAT_VALUE. */
2581 Lisp_Object
2582 make_float (double float_value)
2584 register Lisp_Object val;
2586 /* eassert (!handling_signal); */
2588 MALLOC_BLOCK_INPUT;
2590 if (float_free_list)
2592 /* We use the data field for chaining the free list
2593 so that we won't use the same field that has the mark bit. */
2594 XSETFLOAT (val, float_free_list);
2595 float_free_list = float_free_list->u.chain;
2597 else
2599 if (float_block_index == FLOAT_BLOCK_SIZE)
2601 struct float_block *new
2602 = lisp_align_malloc (sizeof *new, MEM_TYPE_FLOAT);
2603 new->next = float_block;
2604 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2605 float_block = new;
2606 float_block_index = 0;
2607 total_free_floats += FLOAT_BLOCK_SIZE;
2609 XSETFLOAT (val, &float_block->floats[float_block_index]);
2610 float_block_index++;
2613 MALLOC_UNBLOCK_INPUT;
2615 XFLOAT_INIT (val, float_value);
2616 eassert (!FLOAT_MARKED_P (XFLOAT (val)));
2617 consing_since_gc += sizeof (struct Lisp_Float);
2618 floats_consed++;
2619 total_free_floats--;
2620 return val;
2625 /***********************************************************************
2626 Cons Allocation
2627 ***********************************************************************/
2629 /* We store cons cells inside of cons_blocks, allocating a new
2630 cons_block with malloc whenever necessary. Cons cells reclaimed by
2631 GC are put on a free list to be reallocated before allocating
2632 any new cons cells from the latest cons_block. */
2634 #define CONS_BLOCK_SIZE \
2635 (((BLOCK_BYTES - sizeof (struct cons_block *) \
2636 /* The compiler might add padding at the end. */ \
2637 - (sizeof (struct Lisp_Cons) - sizeof (int))) * CHAR_BIT) \
2638 / (sizeof (struct Lisp_Cons) * CHAR_BIT + 1))
2640 #define CONS_BLOCK(fptr) \
2641 ((struct cons_block *) ((uintptr_t) (fptr) & ~(BLOCK_ALIGN - 1)))
2643 #define CONS_INDEX(fptr) \
2644 (((uintptr_t) (fptr) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Cons))
2646 struct cons_block
2648 /* Place `conses' at the beginning, to ease up CONS_INDEX's job. */
2649 struct Lisp_Cons conses[CONS_BLOCK_SIZE];
2650 int gcmarkbits[1 + CONS_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2651 struct cons_block *next;
2654 #define CONS_MARKED_P(fptr) \
2655 GETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2657 #define CONS_MARK(fptr) \
2658 SETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2660 #define CONS_UNMARK(fptr) \
2661 UNSETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2663 /* Current cons_block. */
2665 static struct cons_block *cons_block;
2667 /* Index of first unused Lisp_Cons in the current block. */
2669 static int cons_block_index = CONS_BLOCK_SIZE;
2671 /* Free-list of Lisp_Cons structures. */
2673 static struct Lisp_Cons *cons_free_list;
2675 /* Explicitly free a cons cell by putting it on the free-list. */
2677 void
2678 free_cons (struct Lisp_Cons *ptr)
2680 ptr->u.chain = cons_free_list;
2681 #if GC_MARK_STACK
2682 ptr->car = Vdead;
2683 #endif
2684 cons_free_list = ptr;
2685 consing_since_gc -= sizeof *ptr;
2686 total_free_conses++;
2689 DEFUN ("cons", Fcons, Scons, 2, 2, 0,
2690 doc: /* Create a new cons, give it CAR and CDR as components, and return it. */)
2691 (Lisp_Object car, Lisp_Object cdr)
2693 register Lisp_Object val;
2695 /* eassert (!handling_signal); */
2697 MALLOC_BLOCK_INPUT;
2699 if (cons_free_list)
2701 /* We use the cdr for chaining the free list
2702 so that we won't use the same field that has the mark bit. */
2703 XSETCONS (val, cons_free_list);
2704 cons_free_list = cons_free_list->u.chain;
2706 else
2708 if (cons_block_index == CONS_BLOCK_SIZE)
2710 struct cons_block *new
2711 = lisp_align_malloc (sizeof *new, MEM_TYPE_CONS);
2712 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2713 new->next = cons_block;
2714 cons_block = new;
2715 cons_block_index = 0;
2716 total_free_conses += CONS_BLOCK_SIZE;
2718 XSETCONS (val, &cons_block->conses[cons_block_index]);
2719 cons_block_index++;
2722 MALLOC_UNBLOCK_INPUT;
2724 XSETCAR (val, car);
2725 XSETCDR (val, cdr);
2726 eassert (!CONS_MARKED_P (XCONS (val)));
2727 consing_since_gc += sizeof (struct Lisp_Cons);
2728 total_free_conses--;
2729 cons_cells_consed++;
2730 return val;
2733 #ifdef GC_CHECK_CONS_LIST
2734 /* Get an error now if there's any junk in the cons free list. */
2735 void
2736 check_cons_list (void)
2738 struct Lisp_Cons *tail = cons_free_list;
2740 while (tail)
2741 tail = tail->u.chain;
2743 #endif
2745 /* Make a list of 1, 2, 3, 4 or 5 specified objects. */
2747 Lisp_Object
2748 list1 (Lisp_Object arg1)
2750 return Fcons (arg1, Qnil);
2753 Lisp_Object
2754 list2 (Lisp_Object arg1, Lisp_Object arg2)
2756 return Fcons (arg1, Fcons (arg2, Qnil));
2760 Lisp_Object
2761 list3 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
2763 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Qnil)));
2767 Lisp_Object
2768 list4 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4)
2770 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4, Qnil))));
2774 Lisp_Object
2775 list5 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4, Lisp_Object arg5)
2777 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4,
2778 Fcons (arg5, Qnil)))));
2781 /* Make a list of COUNT Lisp_Objects, where ARG is the
2782 first one. Allocate conses from pure space if TYPE
2783 is CONSTYPE_PURE, or allocate as usual if type is CONSTYPE_HEAP. */
2785 Lisp_Object
2786 listn (enum constype type, ptrdiff_t count, Lisp_Object arg, ...)
2788 va_list ap;
2789 ptrdiff_t i;
2790 Lisp_Object val, *objp;
2792 /* Change to SAFE_ALLOCA if you hit this eassert. */
2793 eassert (count <= MAX_ALLOCA / word_size);
2795 objp = alloca (count * word_size);
2796 objp[0] = arg;
2797 va_start (ap, arg);
2798 for (i = 1; i < count; i++)
2799 objp[i] = va_arg (ap, Lisp_Object);
2800 va_end (ap);
2802 for (val = Qnil, i = count - 1; i >= 0; i--)
2804 if (type == CONSTYPE_PURE)
2805 val = pure_cons (objp[i], val);
2806 else if (type == CONSTYPE_HEAP)
2807 val = Fcons (objp[i], val);
2808 else
2809 abort ();
2811 return val;
2814 DEFUN ("list", Flist, Slist, 0, MANY, 0,
2815 doc: /* Return a newly created list with specified arguments as elements.
2816 Any number of arguments, even zero arguments, are allowed.
2817 usage: (list &rest OBJECTS) */)
2818 (ptrdiff_t nargs, Lisp_Object *args)
2820 register Lisp_Object val;
2821 val = Qnil;
2823 while (nargs > 0)
2825 nargs--;
2826 val = Fcons (args[nargs], val);
2828 return val;
2832 DEFUN ("make-list", Fmake_list, Smake_list, 2, 2, 0,
2833 doc: /* Return a newly created list of length LENGTH, with each element being INIT. */)
2834 (register Lisp_Object length, Lisp_Object init)
2836 register Lisp_Object val;
2837 register EMACS_INT size;
2839 CHECK_NATNUM (length);
2840 size = XFASTINT (length);
2842 val = Qnil;
2843 while (size > 0)
2845 val = Fcons (init, val);
2846 --size;
2848 if (size > 0)
2850 val = Fcons (init, val);
2851 --size;
2853 if (size > 0)
2855 val = Fcons (init, val);
2856 --size;
2858 if (size > 0)
2860 val = Fcons (init, val);
2861 --size;
2863 if (size > 0)
2865 val = Fcons (init, val);
2866 --size;
2872 QUIT;
2875 return val;
2880 /***********************************************************************
2881 Vector Allocation
2882 ***********************************************************************/
2884 /* This value is balanced well enough to avoid too much internal overhead
2885 for the most common cases; it's not required to be a power of two, but
2886 it's expected to be a mult-of-ROUNDUP_SIZE (see below). */
2888 #define VECTOR_BLOCK_SIZE 4096
2890 /* Align allocation request sizes to be a multiple of ROUNDUP_SIZE. */
2891 enum
2893 roundup_size = COMMON_MULTIPLE (word_size, USE_LSB_TAG ? GCALIGNMENT : 1)
2896 /* ROUNDUP_SIZE must be a power of 2. */
2897 verify ((roundup_size & (roundup_size - 1)) == 0);
2899 /* Verify assumptions described above. */
2900 verify ((VECTOR_BLOCK_SIZE % roundup_size) == 0);
2901 verify (VECTOR_BLOCK_SIZE <= (1 << PSEUDOVECTOR_SIZE_BITS));
2903 /* Round up X to nearest mult-of-ROUNDUP_SIZE. */
2905 #define vroundup(x) (((x) + (roundup_size - 1)) & ~(roundup_size - 1))
2907 /* Rounding helps to maintain alignment constraints if USE_LSB_TAG. */
2909 #define VECTOR_BLOCK_BYTES (VECTOR_BLOCK_SIZE - vroundup (sizeof (void *)))
2911 /* Size of the minimal vector allocated from block. */
2913 #define VBLOCK_BYTES_MIN vroundup (sizeof (struct Lisp_Vector))
2915 /* Size of the largest vector allocated from block. */
2917 #define VBLOCK_BYTES_MAX \
2918 vroundup ((VECTOR_BLOCK_BYTES / 2) - word_size)
2920 /* We maintain one free list for each possible block-allocated
2921 vector size, and this is the number of free lists we have. */
2923 #define VECTOR_MAX_FREE_LIST_INDEX \
2924 ((VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN) / roundup_size + 1)
2926 /* Common shortcut to advance vector pointer over a block data. */
2928 #define ADVANCE(v, nbytes) ((struct Lisp_Vector *) ((char *) (v) + (nbytes)))
2930 /* Common shortcut to calculate NBYTES-vector index in VECTOR_FREE_LISTS. */
2932 #define VINDEX(nbytes) (((nbytes) - VBLOCK_BYTES_MIN) / roundup_size)
2934 /* Common shortcut to setup vector on a free list. */
2936 #define SETUP_ON_FREE_LIST(v, nbytes, index) \
2937 do { \
2938 XSETPVECTYPESIZE (v, PVEC_FREE, nbytes); \
2939 eassert ((nbytes) % roundup_size == 0); \
2940 (index) = VINDEX (nbytes); \
2941 eassert ((index) < VECTOR_MAX_FREE_LIST_INDEX); \
2942 (v)->header.next.vector = vector_free_lists[index]; \
2943 vector_free_lists[index] = (v); \
2944 total_free_vector_slots += (nbytes) / word_size; \
2945 } while (0)
2947 struct vector_block
2949 char data[VECTOR_BLOCK_BYTES];
2950 struct vector_block *next;
2953 /* Chain of vector blocks. */
2955 static struct vector_block *vector_blocks;
2957 /* Vector free lists, where NTH item points to a chain of free
2958 vectors of the same NBYTES size, so NTH == VINDEX (NBYTES). */
2960 static struct Lisp_Vector *vector_free_lists[VECTOR_MAX_FREE_LIST_INDEX];
2962 /* Singly-linked list of large vectors. */
2964 static struct Lisp_Vector *large_vectors;
2966 /* The only vector with 0 slots, allocated from pure space. */
2968 Lisp_Object zero_vector;
2970 /* Number of live vectors. */
2972 static EMACS_INT total_vectors;
2974 /* Total size of live and free vectors, in Lisp_Object units. */
2976 static EMACS_INT total_vector_slots, total_free_vector_slots;
2978 /* Get a new vector block. */
2980 static struct vector_block *
2981 allocate_vector_block (void)
2983 struct vector_block *block = xmalloc (sizeof *block);
2985 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
2986 mem_insert (block->data, block->data + VECTOR_BLOCK_BYTES,
2987 MEM_TYPE_VECTOR_BLOCK);
2988 #endif
2990 block->next = vector_blocks;
2991 vector_blocks = block;
2992 return block;
2995 /* Called once to initialize vector allocation. */
2997 static void
2998 init_vectors (void)
3000 zero_vector = make_pure_vector (0);
3003 /* Allocate vector from a vector block. */
3005 static struct Lisp_Vector *
3006 allocate_vector_from_block (size_t nbytes)
3008 struct Lisp_Vector *vector, *rest;
3009 struct vector_block *block;
3010 size_t index, restbytes;
3012 eassert (VBLOCK_BYTES_MIN <= nbytes && nbytes <= VBLOCK_BYTES_MAX);
3013 eassert (nbytes % roundup_size == 0);
3015 /* First, try to allocate from a free list
3016 containing vectors of the requested size. */
3017 index = VINDEX (nbytes);
3018 if (vector_free_lists[index])
3020 vector = vector_free_lists[index];
3021 vector_free_lists[index] = vector->header.next.vector;
3022 vector->header.next.nbytes = nbytes;
3023 total_free_vector_slots -= nbytes / word_size;
3024 return vector;
3027 /* Next, check free lists containing larger vectors. Since
3028 we will split the result, we should have remaining space
3029 large enough to use for one-slot vector at least. */
3030 for (index = VINDEX (nbytes + VBLOCK_BYTES_MIN);
3031 index < VECTOR_MAX_FREE_LIST_INDEX; index++)
3032 if (vector_free_lists[index])
3034 /* This vector is larger than requested. */
3035 vector = vector_free_lists[index];
3036 vector_free_lists[index] = vector->header.next.vector;
3037 vector->header.next.nbytes = nbytes;
3038 total_free_vector_slots -= nbytes / word_size;
3040 /* Excess bytes are used for the smaller vector,
3041 which should be set on an appropriate free list. */
3042 restbytes = index * roundup_size + VBLOCK_BYTES_MIN - nbytes;
3043 eassert (restbytes % roundup_size == 0);
3044 rest = ADVANCE (vector, nbytes);
3045 SETUP_ON_FREE_LIST (rest, restbytes, index);
3046 return vector;
3049 /* Finally, need a new vector block. */
3050 block = allocate_vector_block ();
3052 /* New vector will be at the beginning of this block. */
3053 vector = (struct Lisp_Vector *) block->data;
3054 vector->header.next.nbytes = nbytes;
3056 /* If the rest of space from this block is large enough
3057 for one-slot vector at least, set up it on a free list. */
3058 restbytes = VECTOR_BLOCK_BYTES - nbytes;
3059 if (restbytes >= VBLOCK_BYTES_MIN)
3061 eassert (restbytes % roundup_size == 0);
3062 rest = ADVANCE (vector, nbytes);
3063 SETUP_ON_FREE_LIST (rest, restbytes, index);
3065 return vector;
3068 /* Nonzero if VECTOR pointer is valid pointer inside BLOCK. */
3070 #define VECTOR_IN_BLOCK(vector, block) \
3071 ((char *) (vector) <= (block)->data \
3072 + VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN)
3074 /* Number of bytes used by vector-block-allocated object. This is the only
3075 place where we actually use the `nbytes' field of the vector-header.
3076 I.e. we could get rid of the `nbytes' field by computing it based on the
3077 vector-type. */
3079 #define PSEUDOVECTOR_NBYTES(vector) \
3080 (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FREE) \
3081 ? vector->header.size & PSEUDOVECTOR_SIZE_MASK \
3082 : vector->header.next.nbytes)
3084 /* Reclaim space used by unmarked vectors. */
3086 static void
3087 sweep_vectors (void)
3089 struct vector_block *block = vector_blocks, **bprev = &vector_blocks;
3090 struct Lisp_Vector *vector, *next, **vprev = &large_vectors;
3092 total_vectors = total_vector_slots = total_free_vector_slots = 0;
3093 memset (vector_free_lists, 0, sizeof (vector_free_lists));
3095 /* Looking through vector blocks. */
3097 for (block = vector_blocks; block; block = *bprev)
3099 bool free_this_block = 0;
3101 for (vector = (struct Lisp_Vector *) block->data;
3102 VECTOR_IN_BLOCK (vector, block); vector = next)
3104 if (VECTOR_MARKED_P (vector))
3106 VECTOR_UNMARK (vector);
3107 total_vectors++;
3108 total_vector_slots += vector->header.next.nbytes / word_size;
3109 next = ADVANCE (vector, vector->header.next.nbytes);
3111 else
3113 ptrdiff_t nbytes = PSEUDOVECTOR_NBYTES (vector);
3114 ptrdiff_t total_bytes = nbytes;
3116 next = ADVANCE (vector, nbytes);
3118 /* While NEXT is not marked, try to coalesce with VECTOR,
3119 thus making VECTOR of the largest possible size. */
3121 while (VECTOR_IN_BLOCK (next, block))
3123 if (VECTOR_MARKED_P (next))
3124 break;
3125 nbytes = PSEUDOVECTOR_NBYTES (next);
3126 total_bytes += nbytes;
3127 next = ADVANCE (next, nbytes);
3130 eassert (total_bytes % roundup_size == 0);
3132 if (vector == (struct Lisp_Vector *) block->data
3133 && !VECTOR_IN_BLOCK (next, block))
3134 /* This block should be freed because all of it's
3135 space was coalesced into the only free vector. */
3136 free_this_block = 1;
3137 else
3139 int tmp;
3140 SETUP_ON_FREE_LIST (vector, total_bytes, tmp);
3145 if (free_this_block)
3147 *bprev = block->next;
3148 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
3149 mem_delete (mem_find (block->data));
3150 #endif
3151 xfree (block);
3153 else
3154 bprev = &block->next;
3157 /* Sweep large vectors. */
3159 for (vector = large_vectors; vector; vector = *vprev)
3161 if (VECTOR_MARKED_P (vector))
3163 VECTOR_UNMARK (vector);
3164 total_vectors++;
3165 if (vector->header.size & PSEUDOVECTOR_FLAG)
3167 struct Lisp_Bool_Vector *b = (struct Lisp_Bool_Vector *) vector;
3169 /* All non-bool pseudovectors are small enough to be allocated
3170 from vector blocks. This code should be redesigned if some
3171 pseudovector type grows beyond VBLOCK_BYTES_MAX. */
3172 eassert (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_BOOL_VECTOR));
3174 total_vector_slots
3175 += (bool_header_size
3176 + ((b->size + BOOL_VECTOR_BITS_PER_CHAR - 1)
3177 / BOOL_VECTOR_BITS_PER_CHAR)) / word_size;
3179 else
3180 total_vector_slots
3181 += header_size / word_size + vector->header.size;
3182 vprev = &vector->header.next.vector;
3184 else
3186 *vprev = vector->header.next.vector;
3187 lisp_free (vector);
3192 /* Value is a pointer to a newly allocated Lisp_Vector structure
3193 with room for LEN Lisp_Objects. */
3195 static struct Lisp_Vector *
3196 allocate_vectorlike (ptrdiff_t len)
3198 struct Lisp_Vector *p;
3200 MALLOC_BLOCK_INPUT;
3202 /* This gets triggered by code which I haven't bothered to fix. --Stef */
3203 /* eassert (!handling_signal); */
3205 if (len == 0)
3206 p = XVECTOR (zero_vector);
3207 else
3209 size_t nbytes = header_size + len * word_size;
3211 #ifdef DOUG_LEA_MALLOC
3212 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
3213 because mapped region contents are not preserved in
3214 a dumped Emacs. */
3215 mallopt (M_MMAP_MAX, 0);
3216 #endif
3218 if (nbytes <= VBLOCK_BYTES_MAX)
3219 p = allocate_vector_from_block (vroundup (nbytes));
3220 else
3222 p = lisp_malloc (nbytes, MEM_TYPE_VECTORLIKE);
3223 p->header.next.vector = large_vectors;
3224 large_vectors = p;
3227 #ifdef DOUG_LEA_MALLOC
3228 /* Back to a reasonable maximum of mmap'ed areas. */
3229 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
3230 #endif
3232 consing_since_gc += nbytes;
3233 vector_cells_consed += len;
3236 MALLOC_UNBLOCK_INPUT;
3238 return p;
3242 /* Allocate a vector with LEN slots. */
3244 struct Lisp_Vector *
3245 allocate_vector (EMACS_INT len)
3247 struct Lisp_Vector *v;
3248 ptrdiff_t nbytes_max = min (PTRDIFF_MAX, SIZE_MAX);
3250 if (min ((nbytes_max - header_size) / word_size, MOST_POSITIVE_FIXNUM) < len)
3251 memory_full (SIZE_MAX);
3252 v = allocate_vectorlike (len);
3253 v->header.size = len;
3254 return v;
3258 /* Allocate other vector-like structures. */
3260 struct Lisp_Vector *
3261 allocate_pseudovector (int memlen, int lisplen, int tag)
3263 struct Lisp_Vector *v = allocate_vectorlike (memlen);
3264 int i;
3266 /* Only the first lisplen slots will be traced normally by the GC. */
3267 for (i = 0; i < lisplen; ++i)
3268 v->contents[i] = Qnil;
3270 XSETPVECTYPESIZE (v, tag, lisplen);
3271 return v;
3274 struct buffer *
3275 allocate_buffer (void)
3277 struct buffer *b = lisp_malloc (sizeof *b, MEM_TYPE_BUFFER);
3279 XSETPVECTYPESIZE (b, PVEC_BUFFER, (offsetof (struct buffer, own_text)
3280 - header_size) / word_size);
3281 /* Note that the fields of B are not initialized. */
3282 return b;
3285 struct Lisp_Hash_Table *
3286 allocate_hash_table (void)
3288 return ALLOCATE_PSEUDOVECTOR (struct Lisp_Hash_Table, count, PVEC_HASH_TABLE);
3291 struct window *
3292 allocate_window (void)
3294 struct window *w;
3296 w = ALLOCATE_PSEUDOVECTOR (struct window, current_matrix, PVEC_WINDOW);
3297 /* Users assumes that non-Lisp data is zeroed. */
3298 memset (&w->current_matrix, 0,
3299 sizeof (*w) - offsetof (struct window, current_matrix));
3300 return w;
3303 struct terminal *
3304 allocate_terminal (void)
3306 struct terminal *t;
3308 t = ALLOCATE_PSEUDOVECTOR (struct terminal, next_terminal, PVEC_TERMINAL);
3309 /* Users assumes that non-Lisp data is zeroed. */
3310 memset (&t->next_terminal, 0,
3311 sizeof (*t) - offsetof (struct terminal, next_terminal));
3312 return t;
3315 struct frame *
3316 allocate_frame (void)
3318 struct frame *f;
3320 f = ALLOCATE_PSEUDOVECTOR (struct frame, face_cache, PVEC_FRAME);
3321 /* Users assumes that non-Lisp data is zeroed. */
3322 memset (&f->face_cache, 0,
3323 sizeof (*f) - offsetof (struct frame, face_cache));
3324 return f;
3327 struct Lisp_Process *
3328 allocate_process (void)
3330 struct Lisp_Process *p;
3332 p = ALLOCATE_PSEUDOVECTOR (struct Lisp_Process, pid, PVEC_PROCESS);
3333 /* Users assumes that non-Lisp data is zeroed. */
3334 memset (&p->pid, 0,
3335 sizeof (*p) - offsetof (struct Lisp_Process, pid));
3336 return p;
3339 DEFUN ("make-vector", Fmake_vector, Smake_vector, 2, 2, 0,
3340 doc: /* Return a newly created vector of length LENGTH, with each element being INIT.
3341 See also the function `vector'. */)
3342 (register Lisp_Object length, Lisp_Object init)
3344 Lisp_Object vector;
3345 register ptrdiff_t sizei;
3346 register ptrdiff_t i;
3347 register struct Lisp_Vector *p;
3349 CHECK_NATNUM (length);
3351 p = allocate_vector (XFASTINT (length));
3352 sizei = XFASTINT (length);
3353 for (i = 0; i < sizei; i++)
3354 p->contents[i] = init;
3356 XSETVECTOR (vector, p);
3357 return vector;
3361 DEFUN ("vector", Fvector, Svector, 0, MANY, 0,
3362 doc: /* Return a newly created vector with specified arguments as elements.
3363 Any number of arguments, even zero arguments, are allowed.
3364 usage: (vector &rest OBJECTS) */)
3365 (ptrdiff_t nargs, Lisp_Object *args)
3367 register Lisp_Object len, val;
3368 ptrdiff_t i;
3369 register struct Lisp_Vector *p;
3371 XSETFASTINT (len, nargs);
3372 val = Fmake_vector (len, Qnil);
3373 p = XVECTOR (val);
3374 for (i = 0; i < nargs; i++)
3375 p->contents[i] = args[i];
3376 return val;
3379 void
3380 make_byte_code (struct Lisp_Vector *v)
3382 if (v->header.size > 1 && STRINGP (v->contents[1])
3383 && STRING_MULTIBYTE (v->contents[1]))
3384 /* BYTECODE-STRING must have been produced by Emacs 20.2 or the
3385 earlier because they produced a raw 8-bit string for byte-code
3386 and now such a byte-code string is loaded as multibyte while
3387 raw 8-bit characters converted to multibyte form. Thus, now we
3388 must convert them back to the original unibyte form. */
3389 v->contents[1] = Fstring_as_unibyte (v->contents[1]);
3390 XSETPVECTYPE (v, PVEC_COMPILED);
3393 DEFUN ("make-byte-code", Fmake_byte_code, Smake_byte_code, 4, MANY, 0,
3394 doc: /* Create a byte-code object with specified arguments as elements.
3395 The arguments should be the ARGLIST, bytecode-string BYTE-CODE, constant
3396 vector CONSTANTS, maximum stack size DEPTH, (optional) DOCSTRING,
3397 and (optional) INTERACTIVE-SPEC.
3398 The first four arguments are required; at most six have any
3399 significance.
3400 The ARGLIST can be either like the one of `lambda', in which case the arguments
3401 will be dynamically bound before executing the byte code, or it can be an
3402 integer of the form NNNNNNNRMMMMMMM where the 7bit MMMMMMM specifies the
3403 minimum number of arguments, the 7-bit NNNNNNN specifies the maximum number
3404 of arguments (ignoring &rest) and the R bit specifies whether there is a &rest
3405 argument to catch the left-over arguments. If such an integer is used, the
3406 arguments will not be dynamically bound but will be instead pushed on the
3407 stack before executing the byte-code.
3408 usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INTERACTIVE-SPEC &rest ELEMENTS) */)
3409 (ptrdiff_t nargs, Lisp_Object *args)
3411 register Lisp_Object len, val;
3412 ptrdiff_t i;
3413 register struct Lisp_Vector *p;
3415 /* We used to purecopy everything here, if purify-flga was set. This worked
3416 OK for Emacs-23, but with Emacs-24's lexical binding code, it can be
3417 dangerous, since make-byte-code is used during execution to build
3418 closures, so any closure built during the preload phase would end up
3419 copied into pure space, including its free variables, which is sometimes
3420 just wasteful and other times plainly wrong (e.g. those free vars may want
3421 to be setcar'd). */
3423 XSETFASTINT (len, nargs);
3424 val = Fmake_vector (len, Qnil);
3426 p = XVECTOR (val);
3427 for (i = 0; i < nargs; i++)
3428 p->contents[i] = args[i];
3429 make_byte_code (p);
3430 XSETCOMPILED (val, p);
3431 return val;
3436 /***********************************************************************
3437 Symbol Allocation
3438 ***********************************************************************/
3440 /* Like struct Lisp_Symbol, but padded so that the size is a multiple
3441 of the required alignment if LSB tags are used. */
3443 union aligned_Lisp_Symbol
3445 struct Lisp_Symbol s;
3446 #if USE_LSB_TAG
3447 unsigned char c[(sizeof (struct Lisp_Symbol) + GCALIGNMENT - 1)
3448 & -GCALIGNMENT];
3449 #endif
3452 /* Each symbol_block is just under 1020 bytes long, since malloc
3453 really allocates in units of powers of two and uses 4 bytes for its
3454 own overhead. */
3456 #define SYMBOL_BLOCK_SIZE \
3457 ((1020 - sizeof (struct symbol_block *)) / sizeof (union aligned_Lisp_Symbol))
3459 struct symbol_block
3461 /* Place `symbols' first, to preserve alignment. */
3462 union aligned_Lisp_Symbol symbols[SYMBOL_BLOCK_SIZE];
3463 struct symbol_block *next;
3466 /* Current symbol block and index of first unused Lisp_Symbol
3467 structure in it. */
3469 static struct symbol_block *symbol_block;
3470 static int symbol_block_index = SYMBOL_BLOCK_SIZE;
3472 /* List of free symbols. */
3474 static struct Lisp_Symbol *symbol_free_list;
3476 DEFUN ("make-symbol", Fmake_symbol, Smake_symbol, 1, 1, 0,
3477 doc: /* Return a newly allocated uninterned symbol whose name is NAME.
3478 Its value and function definition are void, and its property list is nil. */)
3479 (Lisp_Object name)
3481 register Lisp_Object val;
3482 register struct Lisp_Symbol *p;
3484 CHECK_STRING (name);
3486 /* eassert (!handling_signal); */
3488 MALLOC_BLOCK_INPUT;
3490 if (symbol_free_list)
3492 XSETSYMBOL (val, symbol_free_list);
3493 symbol_free_list = symbol_free_list->next;
3495 else
3497 if (symbol_block_index == SYMBOL_BLOCK_SIZE)
3499 struct symbol_block *new
3500 = lisp_malloc (sizeof *new, MEM_TYPE_SYMBOL);
3501 new->next = symbol_block;
3502 symbol_block = new;
3503 symbol_block_index = 0;
3504 total_free_symbols += SYMBOL_BLOCK_SIZE;
3506 XSETSYMBOL (val, &symbol_block->symbols[symbol_block_index].s);
3507 symbol_block_index++;
3510 MALLOC_UNBLOCK_INPUT;
3512 p = XSYMBOL (val);
3513 set_symbol_name (val, name);
3514 set_symbol_plist (val, Qnil);
3515 p->redirect = SYMBOL_PLAINVAL;
3516 SET_SYMBOL_VAL (p, Qunbound);
3517 set_symbol_function (val, Qunbound);
3518 set_symbol_next (val, NULL);
3519 p->gcmarkbit = 0;
3520 p->interned = SYMBOL_UNINTERNED;
3521 p->constant = 0;
3522 p->declared_special = 0;
3523 consing_since_gc += sizeof (struct Lisp_Symbol);
3524 symbols_consed++;
3525 total_free_symbols--;
3526 return val;
3531 /***********************************************************************
3532 Marker (Misc) Allocation
3533 ***********************************************************************/
3535 /* Like union Lisp_Misc, but padded so that its size is a multiple of
3536 the required alignment when LSB tags are used. */
3538 union aligned_Lisp_Misc
3540 union Lisp_Misc m;
3541 #if USE_LSB_TAG
3542 unsigned char c[(sizeof (union Lisp_Misc) + GCALIGNMENT - 1)
3543 & -GCALIGNMENT];
3544 #endif
3547 /* Allocation of markers and other objects that share that structure.
3548 Works like allocation of conses. */
3550 #define MARKER_BLOCK_SIZE \
3551 ((1020 - sizeof (struct marker_block *)) / sizeof (union aligned_Lisp_Misc))
3553 struct marker_block
3555 /* Place `markers' first, to preserve alignment. */
3556 union aligned_Lisp_Misc markers[MARKER_BLOCK_SIZE];
3557 struct marker_block *next;
3560 static struct marker_block *marker_block;
3561 static int marker_block_index = MARKER_BLOCK_SIZE;
3563 static union Lisp_Misc *marker_free_list;
3565 /* Return a newly allocated Lisp_Misc object of specified TYPE. */
3567 static Lisp_Object
3568 allocate_misc (enum Lisp_Misc_Type type)
3570 Lisp_Object val;
3572 /* eassert (!handling_signal); */
3574 MALLOC_BLOCK_INPUT;
3576 if (marker_free_list)
3578 XSETMISC (val, marker_free_list);
3579 marker_free_list = marker_free_list->u_free.chain;
3581 else
3583 if (marker_block_index == MARKER_BLOCK_SIZE)
3585 struct marker_block *new = lisp_malloc (sizeof *new, MEM_TYPE_MISC);
3586 new->next = marker_block;
3587 marker_block = new;
3588 marker_block_index = 0;
3589 total_free_markers += MARKER_BLOCK_SIZE;
3591 XSETMISC (val, &marker_block->markers[marker_block_index].m);
3592 marker_block_index++;
3595 MALLOC_UNBLOCK_INPUT;
3597 --total_free_markers;
3598 consing_since_gc += sizeof (union Lisp_Misc);
3599 misc_objects_consed++;
3600 XMISCTYPE (val) = type;
3601 XMISCANY (val)->gcmarkbit = 0;
3602 return val;
3605 /* Free a Lisp_Misc object */
3607 static void
3608 free_misc (Lisp_Object misc)
3610 XMISCTYPE (misc) = Lisp_Misc_Free;
3611 XMISC (misc)->u_free.chain = marker_free_list;
3612 marker_free_list = XMISC (misc);
3613 consing_since_gc -= sizeof (union Lisp_Misc);
3614 total_free_markers++;
3617 /* Return a Lisp_Misc_Save_Value object containing POINTER and
3618 INTEGER. This is used to package C values to call record_unwind_protect.
3619 The unwind function can get the C values back using XSAVE_VALUE. */
3621 Lisp_Object
3622 make_save_value (void *pointer, ptrdiff_t integer)
3624 register Lisp_Object val;
3625 register struct Lisp_Save_Value *p;
3627 val = allocate_misc (Lisp_Misc_Save_Value);
3628 p = XSAVE_VALUE (val);
3629 p->pointer = pointer;
3630 p->integer = integer;
3631 p->dogc = 0;
3632 return val;
3635 /* Return a Lisp_Misc_Overlay object with specified START, END and PLIST. */
3637 Lisp_Object
3638 build_overlay (Lisp_Object start, Lisp_Object end, Lisp_Object plist)
3640 register Lisp_Object overlay;
3642 overlay = allocate_misc (Lisp_Misc_Overlay);
3643 OVERLAY_START (overlay) = start;
3644 OVERLAY_END (overlay) = end;
3645 set_overlay_plist (overlay, plist);
3646 XOVERLAY (overlay)->next = NULL;
3647 return overlay;
3650 DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
3651 doc: /* Return a newly allocated marker which does not point at any place. */)
3652 (void)
3654 register Lisp_Object val;
3655 register struct Lisp_Marker *p;
3657 val = allocate_misc (Lisp_Misc_Marker);
3658 p = XMARKER (val);
3659 p->buffer = 0;
3660 p->bytepos = 0;
3661 p->charpos = 0;
3662 p->next = NULL;
3663 p->insertion_type = 0;
3664 return val;
3667 /* Return a newly allocated marker which points into BUF
3668 at character position CHARPOS and byte position BYTEPOS. */
3670 Lisp_Object
3671 build_marker (struct buffer *buf, ptrdiff_t charpos, ptrdiff_t bytepos)
3673 Lisp_Object obj;
3674 struct Lisp_Marker *m;
3676 /* No dead buffers here. */
3677 eassert (!NILP (BVAR (buf, name)));
3679 /* Every character is at least one byte. */
3680 eassert (charpos <= bytepos);
3682 obj = allocate_misc (Lisp_Misc_Marker);
3683 m = XMARKER (obj);
3684 m->buffer = buf;
3685 m->charpos = charpos;
3686 m->bytepos = bytepos;
3687 m->insertion_type = 0;
3688 m->next = BUF_MARKERS (buf);
3689 BUF_MARKERS (buf) = m;
3690 return obj;
3693 /* Put MARKER back on the free list after using it temporarily. */
3695 void
3696 free_marker (Lisp_Object marker)
3698 unchain_marker (XMARKER (marker));
3699 free_misc (marker);
3703 /* Return a newly created vector or string with specified arguments as
3704 elements. If all the arguments are characters that can fit
3705 in a string of events, make a string; otherwise, make a vector.
3707 Any number of arguments, even zero arguments, are allowed. */
3709 Lisp_Object
3710 make_event_array (register int nargs, Lisp_Object *args)
3712 int i;
3714 for (i = 0; i < nargs; i++)
3715 /* The things that fit in a string
3716 are characters that are in 0...127,
3717 after discarding the meta bit and all the bits above it. */
3718 if (!INTEGERP (args[i])
3719 || (XINT (args[i]) & ~(-CHAR_META)) >= 0200)
3720 return Fvector (nargs, args);
3722 /* Since the loop exited, we know that all the things in it are
3723 characters, so we can make a string. */
3725 Lisp_Object result;
3727 result = Fmake_string (make_number (nargs), make_number (0));
3728 for (i = 0; i < nargs; i++)
3730 SSET (result, i, XINT (args[i]));
3731 /* Move the meta bit to the right place for a string char. */
3732 if (XINT (args[i]) & CHAR_META)
3733 SSET (result, i, SREF (result, i) | 0x80);
3736 return result;
3742 /************************************************************************
3743 Memory Full Handling
3744 ************************************************************************/
3747 /* Called if malloc (NBYTES) returns zero. If NBYTES == SIZE_MAX,
3748 there may have been size_t overflow so that malloc was never
3749 called, or perhaps malloc was invoked successfully but the
3750 resulting pointer had problems fitting into a tagged EMACS_INT. In
3751 either case this counts as memory being full even though malloc did
3752 not fail. */
3754 void
3755 memory_full (size_t nbytes)
3757 /* Do not go into hysterics merely because a large request failed. */
3758 bool enough_free_memory = 0;
3759 if (SPARE_MEMORY < nbytes)
3761 void *p;
3763 MALLOC_BLOCK_INPUT;
3764 p = malloc (SPARE_MEMORY);
3765 if (p)
3767 free (p);
3768 enough_free_memory = 1;
3770 MALLOC_UNBLOCK_INPUT;
3773 if (! enough_free_memory)
3775 int i;
3777 Vmemory_full = Qt;
3779 memory_full_cons_threshold = sizeof (struct cons_block);
3781 /* The first time we get here, free the spare memory. */
3782 for (i = 0; i < sizeof (spare_memory) / sizeof (char *); i++)
3783 if (spare_memory[i])
3785 if (i == 0)
3786 free (spare_memory[i]);
3787 else if (i >= 1 && i <= 4)
3788 lisp_align_free (spare_memory[i]);
3789 else
3790 lisp_free (spare_memory[i]);
3791 spare_memory[i] = 0;
3794 /* Record the space now used. When it decreases substantially,
3795 we can refill the memory reserve. */
3796 #if !defined SYSTEM_MALLOC && !defined SYNC_INPUT
3797 bytes_used_when_full = BYTES_USED;
3798 #endif
3801 /* This used to call error, but if we've run out of memory, we could
3802 get infinite recursion trying to build the string. */
3803 xsignal (Qnil, Vmemory_signal_data);
3806 /* If we released our reserve (due to running out of memory),
3807 and we have a fair amount free once again,
3808 try to set aside another reserve in case we run out once more.
3810 This is called when a relocatable block is freed in ralloc.c,
3811 and also directly from this file, in case we're not using ralloc.c. */
3813 void
3814 refill_memory_reserve (void)
3816 #ifndef SYSTEM_MALLOC
3817 if (spare_memory[0] == 0)
3818 spare_memory[0] = malloc (SPARE_MEMORY);
3819 if (spare_memory[1] == 0)
3820 spare_memory[1] = lisp_align_malloc (sizeof (struct cons_block),
3821 MEM_TYPE_SPARE);
3822 if (spare_memory[2] == 0)
3823 spare_memory[2] = lisp_align_malloc (sizeof (struct cons_block),
3824 MEM_TYPE_SPARE);
3825 if (spare_memory[3] == 0)
3826 spare_memory[3] = lisp_align_malloc (sizeof (struct cons_block),
3827 MEM_TYPE_SPARE);
3828 if (spare_memory[4] == 0)
3829 spare_memory[4] = lisp_align_malloc (sizeof (struct cons_block),
3830 MEM_TYPE_SPARE);
3831 if (spare_memory[5] == 0)
3832 spare_memory[5] = lisp_malloc (sizeof (struct string_block),
3833 MEM_TYPE_SPARE);
3834 if (spare_memory[6] == 0)
3835 spare_memory[6] = lisp_malloc (sizeof (struct string_block),
3836 MEM_TYPE_SPARE);
3837 if (spare_memory[0] && spare_memory[1] && spare_memory[5])
3838 Vmemory_full = Qnil;
3839 #endif
3842 /************************************************************************
3843 C Stack Marking
3844 ************************************************************************/
3846 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
3848 /* Conservative C stack marking requires a method to identify possibly
3849 live Lisp objects given a pointer value. We do this by keeping
3850 track of blocks of Lisp data that are allocated in a red-black tree
3851 (see also the comment of mem_node which is the type of nodes in
3852 that tree). Function lisp_malloc adds information for an allocated
3853 block to the red-black tree with calls to mem_insert, and function
3854 lisp_free removes it with mem_delete. Functions live_string_p etc
3855 call mem_find to lookup information about a given pointer in the
3856 tree, and use that to determine if the pointer points to a Lisp
3857 object or not. */
3859 /* Initialize this part of alloc.c. */
3861 static void
3862 mem_init (void)
3864 mem_z.left = mem_z.right = MEM_NIL;
3865 mem_z.parent = NULL;
3866 mem_z.color = MEM_BLACK;
3867 mem_z.start = mem_z.end = NULL;
3868 mem_root = MEM_NIL;
3872 /* Value is a pointer to the mem_node containing START. Value is
3873 MEM_NIL if there is no node in the tree containing START. */
3875 static inline struct mem_node *
3876 mem_find (void *start)
3878 struct mem_node *p;
3880 if (start < min_heap_address || start > max_heap_address)
3881 return MEM_NIL;
3883 /* Make the search always successful to speed up the loop below. */
3884 mem_z.start = start;
3885 mem_z.end = (char *) start + 1;
3887 p = mem_root;
3888 while (start < p->start || start >= p->end)
3889 p = start < p->start ? p->left : p->right;
3890 return p;
3894 /* Insert a new node into the tree for a block of memory with start
3895 address START, end address END, and type TYPE. Value is a
3896 pointer to the node that was inserted. */
3898 static struct mem_node *
3899 mem_insert (void *start, void *end, enum mem_type type)
3901 struct mem_node *c, *parent, *x;
3903 if (min_heap_address == NULL || start < min_heap_address)
3904 min_heap_address = start;
3905 if (max_heap_address == NULL || end > max_heap_address)
3906 max_heap_address = end;
3908 /* See where in the tree a node for START belongs. In this
3909 particular application, it shouldn't happen that a node is already
3910 present. For debugging purposes, let's check that. */
3911 c = mem_root;
3912 parent = NULL;
3914 #if GC_MARK_STACK != GC_MAKE_GCPROS_NOOPS
3916 while (c != MEM_NIL)
3918 if (start >= c->start && start < c->end)
3919 abort ();
3920 parent = c;
3921 c = start < c->start ? c->left : c->right;
3924 #else /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3926 while (c != MEM_NIL)
3928 parent = c;
3929 c = start < c->start ? c->left : c->right;
3932 #endif /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3934 /* Create a new node. */
3935 #ifdef GC_MALLOC_CHECK
3936 x = _malloc_internal (sizeof *x);
3937 if (x == NULL)
3938 abort ();
3939 #else
3940 x = xmalloc (sizeof *x);
3941 #endif
3942 x->start = start;
3943 x->end = end;
3944 x->type = type;
3945 x->parent = parent;
3946 x->left = x->right = MEM_NIL;
3947 x->color = MEM_RED;
3949 /* Insert it as child of PARENT or install it as root. */
3950 if (parent)
3952 if (start < parent->start)
3953 parent->left = x;
3954 else
3955 parent->right = x;
3957 else
3958 mem_root = x;
3960 /* Re-establish red-black tree properties. */
3961 mem_insert_fixup (x);
3963 return x;
3967 /* Re-establish the red-black properties of the tree, and thereby
3968 balance the tree, after node X has been inserted; X is always red. */
3970 static void
3971 mem_insert_fixup (struct mem_node *x)
3973 while (x != mem_root && x->parent->color == MEM_RED)
3975 /* X is red and its parent is red. This is a violation of
3976 red-black tree property #3. */
3978 if (x->parent == x->parent->parent->left)
3980 /* We're on the left side of our grandparent, and Y is our
3981 "uncle". */
3982 struct mem_node *y = x->parent->parent->right;
3984 if (y->color == MEM_RED)
3986 /* Uncle and parent are red but should be black because
3987 X is red. Change the colors accordingly and proceed
3988 with the grandparent. */
3989 x->parent->color = MEM_BLACK;
3990 y->color = MEM_BLACK;
3991 x->parent->parent->color = MEM_RED;
3992 x = x->parent->parent;
3994 else
3996 /* Parent and uncle have different colors; parent is
3997 red, uncle is black. */
3998 if (x == x->parent->right)
4000 x = x->parent;
4001 mem_rotate_left (x);
4004 x->parent->color = MEM_BLACK;
4005 x->parent->parent->color = MEM_RED;
4006 mem_rotate_right (x->parent->parent);
4009 else
4011 /* This is the symmetrical case of above. */
4012 struct mem_node *y = x->parent->parent->left;
4014 if (y->color == MEM_RED)
4016 x->parent->color = MEM_BLACK;
4017 y->color = MEM_BLACK;
4018 x->parent->parent->color = MEM_RED;
4019 x = x->parent->parent;
4021 else
4023 if (x == x->parent->left)
4025 x = x->parent;
4026 mem_rotate_right (x);
4029 x->parent->color = MEM_BLACK;
4030 x->parent->parent->color = MEM_RED;
4031 mem_rotate_left (x->parent->parent);
4036 /* The root may have been changed to red due to the algorithm. Set
4037 it to black so that property #5 is satisfied. */
4038 mem_root->color = MEM_BLACK;
4042 /* (x) (y)
4043 / \ / \
4044 a (y) ===> (x) c
4045 / \ / \
4046 b c a b */
4048 static void
4049 mem_rotate_left (struct mem_node *x)
4051 struct mem_node *y;
4053 /* Turn y's left sub-tree into x's right sub-tree. */
4054 y = x->right;
4055 x->right = y->left;
4056 if (y->left != MEM_NIL)
4057 y->left->parent = x;
4059 /* Y's parent was x's parent. */
4060 if (y != MEM_NIL)
4061 y->parent = x->parent;
4063 /* Get the parent to point to y instead of x. */
4064 if (x->parent)
4066 if (x == x->parent->left)
4067 x->parent->left = y;
4068 else
4069 x->parent->right = y;
4071 else
4072 mem_root = y;
4074 /* Put x on y's left. */
4075 y->left = x;
4076 if (x != MEM_NIL)
4077 x->parent = y;
4081 /* (x) (Y)
4082 / \ / \
4083 (y) c ===> a (x)
4084 / \ / \
4085 a b b c */
4087 static void
4088 mem_rotate_right (struct mem_node *x)
4090 struct mem_node *y = x->left;
4092 x->left = y->right;
4093 if (y->right != MEM_NIL)
4094 y->right->parent = x;
4096 if (y != MEM_NIL)
4097 y->parent = x->parent;
4098 if (x->parent)
4100 if (x == x->parent->right)
4101 x->parent->right = y;
4102 else
4103 x->parent->left = y;
4105 else
4106 mem_root = y;
4108 y->right = x;
4109 if (x != MEM_NIL)
4110 x->parent = y;
4114 /* Delete node Z from the tree. If Z is null or MEM_NIL, do nothing. */
4116 static void
4117 mem_delete (struct mem_node *z)
4119 struct mem_node *x, *y;
4121 if (!z || z == MEM_NIL)
4122 return;
4124 if (z->left == MEM_NIL || z->right == MEM_NIL)
4125 y = z;
4126 else
4128 y = z->right;
4129 while (y->left != MEM_NIL)
4130 y = y->left;
4133 if (y->left != MEM_NIL)
4134 x = y->left;
4135 else
4136 x = y->right;
4138 x->parent = y->parent;
4139 if (y->parent)
4141 if (y == y->parent->left)
4142 y->parent->left = x;
4143 else
4144 y->parent->right = x;
4146 else
4147 mem_root = x;
4149 if (y != z)
4151 z->start = y->start;
4152 z->end = y->end;
4153 z->type = y->type;
4156 if (y->color == MEM_BLACK)
4157 mem_delete_fixup (x);
4159 #ifdef GC_MALLOC_CHECK
4160 _free_internal (y);
4161 #else
4162 xfree (y);
4163 #endif
4167 /* Re-establish the red-black properties of the tree, after a
4168 deletion. */
4170 static void
4171 mem_delete_fixup (struct mem_node *x)
4173 while (x != mem_root && x->color == MEM_BLACK)
4175 if (x == x->parent->left)
4177 struct mem_node *w = x->parent->right;
4179 if (w->color == MEM_RED)
4181 w->color = MEM_BLACK;
4182 x->parent->color = MEM_RED;
4183 mem_rotate_left (x->parent);
4184 w = x->parent->right;
4187 if (w->left->color == MEM_BLACK && w->right->color == MEM_BLACK)
4189 w->color = MEM_RED;
4190 x = x->parent;
4192 else
4194 if (w->right->color == MEM_BLACK)
4196 w->left->color = MEM_BLACK;
4197 w->color = MEM_RED;
4198 mem_rotate_right (w);
4199 w = x->parent->right;
4201 w->color = x->parent->color;
4202 x->parent->color = MEM_BLACK;
4203 w->right->color = MEM_BLACK;
4204 mem_rotate_left (x->parent);
4205 x = mem_root;
4208 else
4210 struct mem_node *w = x->parent->left;
4212 if (w->color == MEM_RED)
4214 w->color = MEM_BLACK;
4215 x->parent->color = MEM_RED;
4216 mem_rotate_right (x->parent);
4217 w = x->parent->left;
4220 if (w->right->color == MEM_BLACK && w->left->color == MEM_BLACK)
4222 w->color = MEM_RED;
4223 x = x->parent;
4225 else
4227 if (w->left->color == MEM_BLACK)
4229 w->right->color = MEM_BLACK;
4230 w->color = MEM_RED;
4231 mem_rotate_left (w);
4232 w = x->parent->left;
4235 w->color = x->parent->color;
4236 x->parent->color = MEM_BLACK;
4237 w->left->color = MEM_BLACK;
4238 mem_rotate_right (x->parent);
4239 x = mem_root;
4244 x->color = MEM_BLACK;
4248 /* Value is non-zero if P is a pointer to a live Lisp string on
4249 the heap. M is a pointer to the mem_block for P. */
4251 static inline bool
4252 live_string_p (struct mem_node *m, void *p)
4254 if (m->type == MEM_TYPE_STRING)
4256 struct string_block *b = (struct string_block *) m->start;
4257 ptrdiff_t offset = (char *) p - (char *) &b->strings[0];
4259 /* P must point to the start of a Lisp_String structure, and it
4260 must not be on the free-list. */
4261 return (offset >= 0
4262 && offset % sizeof b->strings[0] == 0
4263 && offset < (STRING_BLOCK_SIZE * sizeof b->strings[0])
4264 && ((struct Lisp_String *) p)->data != NULL);
4266 else
4267 return 0;
4271 /* Value is non-zero if P is a pointer to a live Lisp cons on
4272 the heap. M is a pointer to the mem_block for P. */
4274 static inline bool
4275 live_cons_p (struct mem_node *m, void *p)
4277 if (m->type == MEM_TYPE_CONS)
4279 struct cons_block *b = (struct cons_block *) m->start;
4280 ptrdiff_t offset = (char *) p - (char *) &b->conses[0];
4282 /* P must point to the start of a Lisp_Cons, not be
4283 one of the unused cells in the current cons block,
4284 and not be on the free-list. */
4285 return (offset >= 0
4286 && offset % sizeof b->conses[0] == 0
4287 && offset < (CONS_BLOCK_SIZE * sizeof b->conses[0])
4288 && (b != cons_block
4289 || offset / sizeof b->conses[0] < cons_block_index)
4290 && !EQ (((struct Lisp_Cons *) p)->car, Vdead));
4292 else
4293 return 0;
4297 /* Value is non-zero if P is a pointer to a live Lisp symbol on
4298 the heap. M is a pointer to the mem_block for P. */
4300 static inline bool
4301 live_symbol_p (struct mem_node *m, void *p)
4303 if (m->type == MEM_TYPE_SYMBOL)
4305 struct symbol_block *b = (struct symbol_block *) m->start;
4306 ptrdiff_t offset = (char *) p - (char *) &b->symbols[0];
4308 /* P must point to the start of a Lisp_Symbol, not be
4309 one of the unused cells in the current symbol block,
4310 and not be on the free-list. */
4311 return (offset >= 0
4312 && offset % sizeof b->symbols[0] == 0
4313 && offset < (SYMBOL_BLOCK_SIZE * sizeof b->symbols[0])
4314 && (b != symbol_block
4315 || offset / sizeof b->symbols[0] < symbol_block_index)
4316 && !EQ (((struct Lisp_Symbol *)p)->function, Vdead));
4318 else
4319 return 0;
4323 /* Value is non-zero if P is a pointer to a live Lisp float on
4324 the heap. M is a pointer to the mem_block for P. */
4326 static inline bool
4327 live_float_p (struct mem_node *m, void *p)
4329 if (m->type == MEM_TYPE_FLOAT)
4331 struct float_block *b = (struct float_block *) m->start;
4332 ptrdiff_t offset = (char *) p - (char *) &b->floats[0];
4334 /* P must point to the start of a Lisp_Float and not be
4335 one of the unused cells in the current float block. */
4336 return (offset >= 0
4337 && offset % sizeof b->floats[0] == 0
4338 && offset < (FLOAT_BLOCK_SIZE * sizeof b->floats[0])
4339 && (b != float_block
4340 || offset / sizeof b->floats[0] < float_block_index));
4342 else
4343 return 0;
4347 /* Value is non-zero if P is a pointer to a live Lisp Misc on
4348 the heap. M is a pointer to the mem_block for P. */
4350 static inline bool
4351 live_misc_p (struct mem_node *m, void *p)
4353 if (m->type == MEM_TYPE_MISC)
4355 struct marker_block *b = (struct marker_block *) m->start;
4356 ptrdiff_t offset = (char *) p - (char *) &b->markers[0];
4358 /* P must point to the start of a Lisp_Misc, not be
4359 one of the unused cells in the current misc block,
4360 and not be on the free-list. */
4361 return (offset >= 0
4362 && offset % sizeof b->markers[0] == 0
4363 && offset < (MARKER_BLOCK_SIZE * sizeof b->markers[0])
4364 && (b != marker_block
4365 || offset / sizeof b->markers[0] < marker_block_index)
4366 && ((union Lisp_Misc *) p)->u_any.type != Lisp_Misc_Free);
4368 else
4369 return 0;
4373 /* Value is non-zero if P is a pointer to a live vector-like object.
4374 M is a pointer to the mem_block for P. */
4376 static inline bool
4377 live_vector_p (struct mem_node *m, void *p)
4379 if (m->type == MEM_TYPE_VECTOR_BLOCK)
4381 /* This memory node corresponds to a vector block. */
4382 struct vector_block *block = (struct vector_block *) m->start;
4383 struct Lisp_Vector *vector = (struct Lisp_Vector *) block->data;
4385 /* P is in the block's allocation range. Scan the block
4386 up to P and see whether P points to the start of some
4387 vector which is not on a free list. FIXME: check whether
4388 some allocation patterns (probably a lot of short vectors)
4389 may cause a substantial overhead of this loop. */
4390 while (VECTOR_IN_BLOCK (vector, block)
4391 && vector <= (struct Lisp_Vector *) p)
4393 if (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FREE))
4394 vector = ADVANCE (vector, (vector->header.size
4395 & PSEUDOVECTOR_SIZE_MASK));
4396 else if (vector == p)
4397 return 1;
4398 else
4399 vector = ADVANCE (vector, vector->header.next.nbytes);
4402 else if (m->type == MEM_TYPE_VECTORLIKE && p == m->start)
4403 /* This memory node corresponds to a large vector. */
4404 return 1;
4405 return 0;
4409 /* Value is non-zero if P is a pointer to a live buffer. M is a
4410 pointer to the mem_block for P. */
4412 static inline bool
4413 live_buffer_p (struct mem_node *m, void *p)
4415 /* P must point to the start of the block, and the buffer
4416 must not have been killed. */
4417 return (m->type == MEM_TYPE_BUFFER
4418 && p == m->start
4419 && !NILP (((struct buffer *) p)->INTERNAL_FIELD (name)));
4422 #endif /* GC_MARK_STACK || defined GC_MALLOC_CHECK */
4424 #if GC_MARK_STACK
4426 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4428 /* Array of objects that are kept alive because the C stack contains
4429 a pattern that looks like a reference to them . */
4431 #define MAX_ZOMBIES 10
4432 static Lisp_Object zombies[MAX_ZOMBIES];
4434 /* Number of zombie objects. */
4436 static EMACS_INT nzombies;
4438 /* Number of garbage collections. */
4440 static EMACS_INT ngcs;
4442 /* Average percentage of zombies per collection. */
4444 static double avg_zombies;
4446 /* Max. number of live and zombie objects. */
4448 static EMACS_INT max_live, max_zombies;
4450 /* Average number of live objects per GC. */
4452 static double avg_live;
4454 DEFUN ("gc-status", Fgc_status, Sgc_status, 0, 0, "",
4455 doc: /* Show information about live and zombie objects. */)
4456 (void)
4458 Lisp_Object args[8], zombie_list = Qnil;
4459 EMACS_INT i;
4460 for (i = 0; i < min (MAX_ZOMBIES, nzombies); i++)
4461 zombie_list = Fcons (zombies[i], zombie_list);
4462 args[0] = build_string ("%d GCs, avg live/zombies = %.2f/%.2f (%f%%), max %d/%d\nzombies: %S");
4463 args[1] = make_number (ngcs);
4464 args[2] = make_float (avg_live);
4465 args[3] = make_float (avg_zombies);
4466 args[4] = make_float (avg_zombies / avg_live / 100);
4467 args[5] = make_number (max_live);
4468 args[6] = make_number (max_zombies);
4469 args[7] = zombie_list;
4470 return Fmessage (8, args);
4473 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4476 /* Mark OBJ if we can prove it's a Lisp_Object. */
4478 static inline void
4479 mark_maybe_object (Lisp_Object obj)
4481 void *po;
4482 struct mem_node *m;
4484 if (INTEGERP (obj))
4485 return;
4487 po = (void *) XPNTR (obj);
4488 m = mem_find (po);
4490 if (m != MEM_NIL)
4492 bool mark_p = 0;
4494 switch (XTYPE (obj))
4496 case Lisp_String:
4497 mark_p = (live_string_p (m, po)
4498 && !STRING_MARKED_P ((struct Lisp_String *) po));
4499 break;
4501 case Lisp_Cons:
4502 mark_p = (live_cons_p (m, po) && !CONS_MARKED_P (XCONS (obj)));
4503 break;
4505 case Lisp_Symbol:
4506 mark_p = (live_symbol_p (m, po) && !XSYMBOL (obj)->gcmarkbit);
4507 break;
4509 case Lisp_Float:
4510 mark_p = (live_float_p (m, po) && !FLOAT_MARKED_P (XFLOAT (obj)));
4511 break;
4513 case Lisp_Vectorlike:
4514 /* Note: can't check BUFFERP before we know it's a
4515 buffer because checking that dereferences the pointer
4516 PO which might point anywhere. */
4517 if (live_vector_p (m, po))
4518 mark_p = !SUBRP (obj) && !VECTOR_MARKED_P (XVECTOR (obj));
4519 else if (live_buffer_p (m, po))
4520 mark_p = BUFFERP (obj) && !VECTOR_MARKED_P (XBUFFER (obj));
4521 break;
4523 case Lisp_Misc:
4524 mark_p = (live_misc_p (m, po) && !XMISCANY (obj)->gcmarkbit);
4525 break;
4527 default:
4528 break;
4531 if (mark_p)
4533 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4534 if (nzombies < MAX_ZOMBIES)
4535 zombies[nzombies] = obj;
4536 ++nzombies;
4537 #endif
4538 mark_object (obj);
4544 /* If P points to Lisp data, mark that as live if it isn't already
4545 marked. */
4547 static inline void
4548 mark_maybe_pointer (void *p)
4550 struct mem_node *m;
4552 /* Quickly rule out some values which can't point to Lisp data.
4553 USE_LSB_TAG needs Lisp data to be aligned on multiples of GCALIGNMENT.
4554 Otherwise, assume that Lisp data is aligned on even addresses. */
4555 if ((intptr_t) p % (USE_LSB_TAG ? GCALIGNMENT : 2))
4556 return;
4558 m = mem_find (p);
4559 if (m != MEM_NIL)
4561 Lisp_Object obj = Qnil;
4563 switch (m->type)
4565 case MEM_TYPE_NON_LISP:
4566 case MEM_TYPE_SPARE:
4567 /* Nothing to do; not a pointer to Lisp memory. */
4568 break;
4570 case MEM_TYPE_BUFFER:
4571 if (live_buffer_p (m, p) && !VECTOR_MARKED_P ((struct buffer *)p))
4572 XSETVECTOR (obj, p);
4573 break;
4575 case MEM_TYPE_CONS:
4576 if (live_cons_p (m, p) && !CONS_MARKED_P ((struct Lisp_Cons *) p))
4577 XSETCONS (obj, p);
4578 break;
4580 case MEM_TYPE_STRING:
4581 if (live_string_p (m, p)
4582 && !STRING_MARKED_P ((struct Lisp_String *) p))
4583 XSETSTRING (obj, p);
4584 break;
4586 case MEM_TYPE_MISC:
4587 if (live_misc_p (m, p) && !((struct Lisp_Free *) p)->gcmarkbit)
4588 XSETMISC (obj, p);
4589 break;
4591 case MEM_TYPE_SYMBOL:
4592 if (live_symbol_p (m, p) && !((struct Lisp_Symbol *) p)->gcmarkbit)
4593 XSETSYMBOL (obj, p);
4594 break;
4596 case MEM_TYPE_FLOAT:
4597 if (live_float_p (m, p) && !FLOAT_MARKED_P (p))
4598 XSETFLOAT (obj, p);
4599 break;
4601 case MEM_TYPE_VECTORLIKE:
4602 case MEM_TYPE_VECTOR_BLOCK:
4603 if (live_vector_p (m, p))
4605 Lisp_Object tem;
4606 XSETVECTOR (tem, p);
4607 if (!SUBRP (tem) && !VECTOR_MARKED_P (XVECTOR (tem)))
4608 obj = tem;
4610 break;
4612 default:
4613 abort ();
4616 if (!NILP (obj))
4617 mark_object (obj);
4622 /* Alignment of pointer values. Use alignof, as it sometimes returns
4623 a smaller alignment than GCC's __alignof__ and mark_memory might
4624 miss objects if __alignof__ were used. */
4625 #define GC_POINTER_ALIGNMENT alignof (void *)
4627 /* Define POINTERS_MIGHT_HIDE_IN_OBJECTS to 1 if marking via C pointers does
4628 not suffice, which is the typical case. A host where a Lisp_Object is
4629 wider than a pointer might allocate a Lisp_Object in non-adjacent halves.
4630 If USE_LSB_TAG, the bottom half is not a valid pointer, but it should
4631 suffice to widen it to to a Lisp_Object and check it that way. */
4632 #if USE_LSB_TAG || VAL_MAX < UINTPTR_MAX
4633 # if !USE_LSB_TAG && VAL_MAX < UINTPTR_MAX >> GCTYPEBITS
4634 /* If tag bits straddle pointer-word boundaries, neither mark_maybe_pointer
4635 nor mark_maybe_object can follow the pointers. This should not occur on
4636 any practical porting target. */
4637 # error "MSB type bits straddle pointer-word boundaries"
4638 # endif
4639 /* Marking via C pointers does not suffice, because Lisp_Objects contain
4640 pointer words that hold pointers ORed with type bits. */
4641 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 1
4642 #else
4643 /* Marking via C pointers suffices, because Lisp_Objects contain pointer
4644 words that hold unmodified pointers. */
4645 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 0
4646 #endif
4648 /* Mark Lisp objects referenced from the address range START+OFFSET..END
4649 or END+OFFSET..START. */
4651 static void
4652 mark_memory (void *start, void *end)
4653 #if defined (__clang__) && defined (__has_feature)
4654 #if __has_feature(address_sanitizer)
4655 /* Do not allow -faddress-sanitizer to check this function, since it
4656 crosses the function stack boundary, and thus would yield many
4657 false positives. */
4658 __attribute__((no_address_safety_analysis))
4659 #endif
4660 #endif
4662 void **pp;
4663 int i;
4665 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4666 nzombies = 0;
4667 #endif
4669 /* Make START the pointer to the start of the memory region,
4670 if it isn't already. */
4671 if (end < start)
4673 void *tem = start;
4674 start = end;
4675 end = tem;
4678 /* Mark Lisp data pointed to. This is necessary because, in some
4679 situations, the C compiler optimizes Lisp objects away, so that
4680 only a pointer to them remains. Example:
4682 DEFUN ("testme", Ftestme, Stestme, 0, 0, 0, "")
4685 Lisp_Object obj = build_string ("test");
4686 struct Lisp_String *s = XSTRING (obj);
4687 Fgarbage_collect ();
4688 fprintf (stderr, "test `%s'\n", s->data);
4689 return Qnil;
4692 Here, `obj' isn't really used, and the compiler optimizes it
4693 away. The only reference to the life string is through the
4694 pointer `s'. */
4696 for (pp = start; (void *) pp < end; pp++)
4697 for (i = 0; i < sizeof *pp; i += GC_POINTER_ALIGNMENT)
4699 void *p = *(void **) ((char *) pp + i);
4700 mark_maybe_pointer (p);
4701 if (POINTERS_MIGHT_HIDE_IN_OBJECTS)
4702 mark_maybe_object (XIL ((intptr_t) p));
4706 /* setjmp will work with GCC unless NON_SAVING_SETJMP is defined in
4707 the GCC system configuration. In gcc 3.2, the only systems for
4708 which this is so are i386-sco5 non-ELF, i386-sysv3 (maybe included
4709 by others?) and ns32k-pc532-min. */
4711 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
4713 static bool setjmp_tested_p;
4714 static int longjmps_done;
4716 #define SETJMP_WILL_LIKELY_WORK "\
4718 Emacs garbage collector has been changed to use conservative stack\n\
4719 marking. Emacs has determined that the method it uses to do the\n\
4720 marking will likely work on your system, but this isn't sure.\n\
4722 If you are a system-programmer, or can get the help of a local wizard\n\
4723 who is, please take a look at the function mark_stack in alloc.c, and\n\
4724 verify that the methods used are appropriate for your system.\n\
4726 Please mail the result to <emacs-devel@gnu.org>.\n\
4729 #define SETJMP_WILL_NOT_WORK "\
4731 Emacs garbage collector has been changed to use conservative stack\n\
4732 marking. Emacs has determined that the default method it uses to do the\n\
4733 marking will not work on your system. We will need a system-dependent\n\
4734 solution for your system.\n\
4736 Please take a look at the function mark_stack in alloc.c, and\n\
4737 try to find a way to make it work on your system.\n\
4739 Note that you may get false negatives, depending on the compiler.\n\
4740 In particular, you need to use -O with GCC for this test.\n\
4742 Please mail the result to <emacs-devel@gnu.org>.\n\
4746 /* Perform a quick check if it looks like setjmp saves registers in a
4747 jmp_buf. Print a message to stderr saying so. When this test
4748 succeeds, this is _not_ a proof that setjmp is sufficient for
4749 conservative stack marking. Only the sources or a disassembly
4750 can prove that. */
4752 static void
4753 test_setjmp (void)
4755 char buf[10];
4756 register int x;
4757 jmp_buf jbuf;
4759 /* Arrange for X to be put in a register. */
4760 sprintf (buf, "1");
4761 x = strlen (buf);
4762 x = 2 * x - 1;
4764 setjmp (jbuf);
4765 if (longjmps_done == 1)
4767 /* Came here after the longjmp at the end of the function.
4769 If x == 1, the longjmp has restored the register to its
4770 value before the setjmp, and we can hope that setjmp
4771 saves all such registers in the jmp_buf, although that
4772 isn't sure.
4774 For other values of X, either something really strange is
4775 taking place, or the setjmp just didn't save the register. */
4777 if (x == 1)
4778 fprintf (stderr, SETJMP_WILL_LIKELY_WORK);
4779 else
4781 fprintf (stderr, SETJMP_WILL_NOT_WORK);
4782 exit (1);
4786 ++longjmps_done;
4787 x = 2;
4788 if (longjmps_done == 1)
4789 longjmp (jbuf, 1);
4792 #endif /* not GC_SAVE_REGISTERS_ON_STACK && not GC_SETJMP_WORKS */
4795 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4797 /* Abort if anything GCPRO'd doesn't survive the GC. */
4799 static void
4800 check_gcpros (void)
4802 struct gcpro *p;
4803 ptrdiff_t i;
4805 for (p = gcprolist; p; p = p->next)
4806 for (i = 0; i < p->nvars; ++i)
4807 if (!survives_gc_p (p->var[i]))
4808 /* FIXME: It's not necessarily a bug. It might just be that the
4809 GCPRO is unnecessary or should release the object sooner. */
4810 abort ();
4813 #elif GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4815 static void
4816 dump_zombies (void)
4818 int i;
4820 fprintf (stderr, "\nZombies kept alive = %"pI"d:\n", nzombies);
4821 for (i = 0; i < min (MAX_ZOMBIES, nzombies); ++i)
4823 fprintf (stderr, " %d = ", i);
4824 debug_print (zombies[i]);
4828 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4831 /* Mark live Lisp objects on the C stack.
4833 There are several system-dependent problems to consider when
4834 porting this to new architectures:
4836 Processor Registers
4838 We have to mark Lisp objects in CPU registers that can hold local
4839 variables or are used to pass parameters.
4841 If GC_SAVE_REGISTERS_ON_STACK is defined, it should expand to
4842 something that either saves relevant registers on the stack, or
4843 calls mark_maybe_object passing it each register's contents.
4845 If GC_SAVE_REGISTERS_ON_STACK is not defined, the current
4846 implementation assumes that calling setjmp saves registers we need
4847 to see in a jmp_buf which itself lies on the stack. This doesn't
4848 have to be true! It must be verified for each system, possibly
4849 by taking a look at the source code of setjmp.
4851 If __builtin_unwind_init is available (defined by GCC >= 2.8) we
4852 can use it as a machine independent method to store all registers
4853 to the stack. In this case the macros described in the previous
4854 two paragraphs are not used.
4856 Stack Layout
4858 Architectures differ in the way their processor stack is organized.
4859 For example, the stack might look like this
4861 +----------------+
4862 | Lisp_Object | size = 4
4863 +----------------+
4864 | something else | size = 2
4865 +----------------+
4866 | Lisp_Object | size = 4
4867 +----------------+
4868 | ... |
4870 In such a case, not every Lisp_Object will be aligned equally. To
4871 find all Lisp_Object on the stack it won't be sufficient to walk
4872 the stack in steps of 4 bytes. Instead, two passes will be
4873 necessary, one starting at the start of the stack, and a second
4874 pass starting at the start of the stack + 2. Likewise, if the
4875 minimal alignment of Lisp_Objects on the stack is 1, four passes
4876 would be necessary, each one starting with one byte more offset
4877 from the stack start. */
4879 static void
4880 mark_stack (void)
4882 void *end;
4884 #ifdef HAVE___BUILTIN_UNWIND_INIT
4885 /* Force callee-saved registers and register windows onto the stack.
4886 This is the preferred method if available, obviating the need for
4887 machine dependent methods. */
4888 __builtin_unwind_init ();
4889 end = &end;
4890 #else /* not HAVE___BUILTIN_UNWIND_INIT */
4891 #ifndef GC_SAVE_REGISTERS_ON_STACK
4892 /* jmp_buf may not be aligned enough on darwin-ppc64 */
4893 union aligned_jmpbuf {
4894 Lisp_Object o;
4895 jmp_buf j;
4896 } j;
4897 volatile bool stack_grows_down_p = (char *) &j > (char *) stack_base;
4898 #endif
4899 /* This trick flushes the register windows so that all the state of
4900 the process is contained in the stack. */
4901 /* Fixme: Code in the Boehm GC suggests flushing (with `flushrs') is
4902 needed on ia64 too. See mach_dep.c, where it also says inline
4903 assembler doesn't work with relevant proprietary compilers. */
4904 #ifdef __sparc__
4905 #if defined (__sparc64__) && defined (__FreeBSD__)
4906 /* FreeBSD does not have a ta 3 handler. */
4907 asm ("flushw");
4908 #else
4909 asm ("ta 3");
4910 #endif
4911 #endif
4913 /* Save registers that we need to see on the stack. We need to see
4914 registers used to hold register variables and registers used to
4915 pass parameters. */
4916 #ifdef GC_SAVE_REGISTERS_ON_STACK
4917 GC_SAVE_REGISTERS_ON_STACK (end);
4918 #else /* not GC_SAVE_REGISTERS_ON_STACK */
4920 #ifndef GC_SETJMP_WORKS /* If it hasn't been checked yet that
4921 setjmp will definitely work, test it
4922 and print a message with the result
4923 of the test. */
4924 if (!setjmp_tested_p)
4926 setjmp_tested_p = 1;
4927 test_setjmp ();
4929 #endif /* GC_SETJMP_WORKS */
4931 setjmp (j.j);
4932 end = stack_grows_down_p ? (char *) &j + sizeof j : (char *) &j;
4933 #endif /* not GC_SAVE_REGISTERS_ON_STACK */
4934 #endif /* not HAVE___BUILTIN_UNWIND_INIT */
4936 /* This assumes that the stack is a contiguous region in memory. If
4937 that's not the case, something has to be done here to iterate
4938 over the stack segments. */
4939 mark_memory (stack_base, end);
4941 /* Allow for marking a secondary stack, like the register stack on the
4942 ia64. */
4943 #ifdef GC_MARK_SECONDARY_STACK
4944 GC_MARK_SECONDARY_STACK ();
4945 #endif
4947 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4948 check_gcpros ();
4949 #endif
4952 #endif /* GC_MARK_STACK != 0 */
4955 /* Determine whether it is safe to access memory at address P. */
4956 static int
4957 valid_pointer_p (void *p)
4959 #ifdef WINDOWSNT
4960 return w32_valid_pointer_p (p, 16);
4961 #else
4962 int fd[2];
4964 /* Obviously, we cannot just access it (we would SEGV trying), so we
4965 trick the o/s to tell us whether p is a valid pointer.
4966 Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
4967 not validate p in that case. */
4969 if (pipe (fd) == 0)
4971 bool valid = emacs_write (fd[1], (char *) p, 16) == 16;
4972 emacs_close (fd[1]);
4973 emacs_close (fd[0]);
4974 return valid;
4977 return -1;
4978 #endif
4981 /* Return 1 if OBJ is a valid lisp object.
4982 Return 0 if OBJ is NOT a valid lisp object.
4983 Return -1 if we cannot validate OBJ.
4984 This function can be quite slow,
4985 so it should only be used in code for manual debugging. */
4988 valid_lisp_object_p (Lisp_Object obj)
4990 void *p;
4991 #if GC_MARK_STACK
4992 struct mem_node *m;
4993 #endif
4995 if (INTEGERP (obj))
4996 return 1;
4998 p = (void *) XPNTR (obj);
4999 if (PURE_POINTER_P (p))
5000 return 1;
5002 #if !GC_MARK_STACK
5003 return valid_pointer_p (p);
5004 #else
5006 m = mem_find (p);
5008 if (m == MEM_NIL)
5010 int valid = valid_pointer_p (p);
5011 if (valid <= 0)
5012 return valid;
5014 if (SUBRP (obj))
5015 return 1;
5017 return 0;
5020 switch (m->type)
5022 case MEM_TYPE_NON_LISP:
5023 case MEM_TYPE_SPARE:
5024 return 0;
5026 case MEM_TYPE_BUFFER:
5027 return live_buffer_p (m, p);
5029 case MEM_TYPE_CONS:
5030 return live_cons_p (m, p);
5032 case MEM_TYPE_STRING:
5033 return live_string_p (m, p);
5035 case MEM_TYPE_MISC:
5036 return live_misc_p (m, p);
5038 case MEM_TYPE_SYMBOL:
5039 return live_symbol_p (m, p);
5041 case MEM_TYPE_FLOAT:
5042 return live_float_p (m, p);
5044 case MEM_TYPE_VECTORLIKE:
5045 case MEM_TYPE_VECTOR_BLOCK:
5046 return live_vector_p (m, p);
5048 default:
5049 break;
5052 return 0;
5053 #endif
5059 /***********************************************************************
5060 Pure Storage Management
5061 ***********************************************************************/
5063 /* Allocate room for SIZE bytes from pure Lisp storage and return a
5064 pointer to it. TYPE is the Lisp type for which the memory is
5065 allocated. TYPE < 0 means it's not used for a Lisp object. */
5067 static void *
5068 pure_alloc (size_t size, int type)
5070 void *result;
5071 #if USE_LSB_TAG
5072 size_t alignment = GCALIGNMENT;
5073 #else
5074 size_t alignment = alignof (EMACS_INT);
5076 /* Give Lisp_Floats an extra alignment. */
5077 if (type == Lisp_Float)
5078 alignment = alignof (struct Lisp_Float);
5079 #endif
5081 again:
5082 if (type >= 0)
5084 /* Allocate space for a Lisp object from the beginning of the free
5085 space with taking account of alignment. */
5086 result = ALIGN (purebeg + pure_bytes_used_lisp, alignment);
5087 pure_bytes_used_lisp = ((char *)result - (char *)purebeg) + size;
5089 else
5091 /* Allocate space for a non-Lisp object from the end of the free
5092 space. */
5093 pure_bytes_used_non_lisp += size;
5094 result = purebeg + pure_size - pure_bytes_used_non_lisp;
5096 pure_bytes_used = pure_bytes_used_lisp + pure_bytes_used_non_lisp;
5098 if (pure_bytes_used <= pure_size)
5099 return result;
5101 /* Don't allocate a large amount here,
5102 because it might get mmap'd and then its address
5103 might not be usable. */
5104 purebeg = xmalloc (10000);
5105 pure_size = 10000;
5106 pure_bytes_used_before_overflow += pure_bytes_used - size;
5107 pure_bytes_used = 0;
5108 pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
5109 goto again;
5113 /* Print a warning if PURESIZE is too small. */
5115 void
5116 check_pure_size (void)
5118 if (pure_bytes_used_before_overflow)
5119 message (("emacs:0:Pure Lisp storage overflow (approx. %"pI"d"
5120 " bytes needed)"),
5121 pure_bytes_used + pure_bytes_used_before_overflow);
5125 /* Find the byte sequence {DATA[0], ..., DATA[NBYTES-1], '\0'} from
5126 the non-Lisp data pool of the pure storage, and return its start
5127 address. Return NULL if not found. */
5129 static char *
5130 find_string_data_in_pure (const char *data, ptrdiff_t nbytes)
5132 int i;
5133 ptrdiff_t skip, bm_skip[256], last_char_skip, infinity, start, start_max;
5134 const unsigned char *p;
5135 char *non_lisp_beg;
5137 if (pure_bytes_used_non_lisp <= nbytes)
5138 return NULL;
5140 /* Set up the Boyer-Moore table. */
5141 skip = nbytes + 1;
5142 for (i = 0; i < 256; i++)
5143 bm_skip[i] = skip;
5145 p = (const unsigned char *) data;
5146 while (--skip > 0)
5147 bm_skip[*p++] = skip;
5149 last_char_skip = bm_skip['\0'];
5151 non_lisp_beg = purebeg + pure_size - pure_bytes_used_non_lisp;
5152 start_max = pure_bytes_used_non_lisp - (nbytes + 1);
5154 /* See the comments in the function `boyer_moore' (search.c) for the
5155 use of `infinity'. */
5156 infinity = pure_bytes_used_non_lisp + 1;
5157 bm_skip['\0'] = infinity;
5159 p = (const unsigned char *) non_lisp_beg + nbytes;
5160 start = 0;
5163 /* Check the last character (== '\0'). */
5166 start += bm_skip[*(p + start)];
5168 while (start <= start_max);
5170 if (start < infinity)
5171 /* Couldn't find the last character. */
5172 return NULL;
5174 /* No less than `infinity' means we could find the last
5175 character at `p[start - infinity]'. */
5176 start -= infinity;
5178 /* Check the remaining characters. */
5179 if (memcmp (data, non_lisp_beg + start, nbytes) == 0)
5180 /* Found. */
5181 return non_lisp_beg + start;
5183 start += last_char_skip;
5185 while (start <= start_max);
5187 return NULL;
5191 /* Return a string allocated in pure space. DATA is a buffer holding
5192 NCHARS characters, and NBYTES bytes of string data. MULTIBYTE
5193 means make the result string multibyte.
5195 Must get an error if pure storage is full, since if it cannot hold
5196 a large string it may be able to hold conses that point to that
5197 string; then the string is not protected from gc. */
5199 Lisp_Object
5200 make_pure_string (const char *data,
5201 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
5203 Lisp_Object string;
5204 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
5205 s->data = (unsigned char *) find_string_data_in_pure (data, nbytes);
5206 if (s->data == NULL)
5208 s->data = pure_alloc (nbytes + 1, -1);
5209 memcpy (s->data, data, nbytes);
5210 s->data[nbytes] = '\0';
5212 s->size = nchars;
5213 s->size_byte = multibyte ? nbytes : -1;
5214 s->intervals = NULL;
5215 XSETSTRING (string, s);
5216 return string;
5219 /* Return a string allocated in pure space. Do not
5220 allocate the string data, just point to DATA. */
5222 Lisp_Object
5223 make_pure_c_string (const char *data, ptrdiff_t nchars)
5225 Lisp_Object string;
5226 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
5227 s->size = nchars;
5228 s->size_byte = -1;
5229 s->data = (unsigned char *) data;
5230 s->intervals = NULL;
5231 XSETSTRING (string, s);
5232 return string;
5235 /* Return a cons allocated from pure space. Give it pure copies
5236 of CAR as car and CDR as cdr. */
5238 Lisp_Object
5239 pure_cons (Lisp_Object car, Lisp_Object cdr)
5241 Lisp_Object new;
5242 struct Lisp_Cons *p = pure_alloc (sizeof *p, Lisp_Cons);
5243 XSETCONS (new, p);
5244 XSETCAR (new, Fpurecopy (car));
5245 XSETCDR (new, Fpurecopy (cdr));
5246 return new;
5250 /* Value is a float object with value NUM allocated from pure space. */
5252 static Lisp_Object
5253 make_pure_float (double num)
5255 Lisp_Object new;
5256 struct Lisp_Float *p = pure_alloc (sizeof *p, Lisp_Float);
5257 XSETFLOAT (new, p);
5258 XFLOAT_INIT (new, num);
5259 return new;
5263 /* Return a vector with room for LEN Lisp_Objects allocated from
5264 pure space. */
5266 static Lisp_Object
5267 make_pure_vector (ptrdiff_t len)
5269 Lisp_Object new;
5270 size_t size = header_size + len * word_size;
5271 struct Lisp_Vector *p = pure_alloc (size, Lisp_Vectorlike);
5272 XSETVECTOR (new, p);
5273 XVECTOR (new)->header.size = len;
5274 return new;
5278 DEFUN ("purecopy", Fpurecopy, Spurecopy, 1, 1, 0,
5279 doc: /* Make a copy of object OBJ in pure storage.
5280 Recursively copies contents of vectors and cons cells.
5281 Does not copy symbols. Copies strings without text properties. */)
5282 (register Lisp_Object obj)
5284 if (NILP (Vpurify_flag))
5285 return obj;
5287 if (PURE_POINTER_P (XPNTR (obj)))
5288 return obj;
5290 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5292 Lisp_Object tmp = Fgethash (obj, Vpurify_flag, Qnil);
5293 if (!NILP (tmp))
5294 return tmp;
5297 if (CONSP (obj))
5298 obj = pure_cons (XCAR (obj), XCDR (obj));
5299 else if (FLOATP (obj))
5300 obj = make_pure_float (XFLOAT_DATA (obj));
5301 else if (STRINGP (obj))
5302 obj = make_pure_string (SSDATA (obj), SCHARS (obj),
5303 SBYTES (obj),
5304 STRING_MULTIBYTE (obj));
5305 else if (COMPILEDP (obj) || VECTORP (obj))
5307 register struct Lisp_Vector *vec;
5308 register ptrdiff_t i;
5309 ptrdiff_t size;
5311 size = ASIZE (obj);
5312 if (size & PSEUDOVECTOR_FLAG)
5313 size &= PSEUDOVECTOR_SIZE_MASK;
5314 vec = XVECTOR (make_pure_vector (size));
5315 for (i = 0; i < size; i++)
5316 vec->contents[i] = Fpurecopy (AREF (obj, i));
5317 if (COMPILEDP (obj))
5319 XSETPVECTYPE (vec, PVEC_COMPILED);
5320 XSETCOMPILED (obj, vec);
5322 else
5323 XSETVECTOR (obj, vec);
5325 else if (MARKERP (obj))
5326 error ("Attempt to copy a marker to pure storage");
5327 else
5328 /* Not purified, don't hash-cons. */
5329 return obj;
5331 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5332 Fputhash (obj, obj, Vpurify_flag);
5334 return obj;
5339 /***********************************************************************
5340 Protection from GC
5341 ***********************************************************************/
5343 /* Put an entry in staticvec, pointing at the variable with address
5344 VARADDRESS. */
5346 void
5347 staticpro (Lisp_Object *varaddress)
5349 staticvec[staticidx++] = varaddress;
5350 if (staticidx >= NSTATICS)
5351 abort ();
5355 /***********************************************************************
5356 Protection from GC
5357 ***********************************************************************/
5359 /* Temporarily prevent garbage collection. */
5361 ptrdiff_t
5362 inhibit_garbage_collection (void)
5364 ptrdiff_t count = SPECPDL_INDEX ();
5366 specbind (Qgc_cons_threshold, make_number (MOST_POSITIVE_FIXNUM));
5367 return count;
5370 /* Used to avoid possible overflows when
5371 converting from C to Lisp integers. */
5373 static inline Lisp_Object
5374 bounded_number (EMACS_INT number)
5376 return make_number (min (MOST_POSITIVE_FIXNUM, number));
5379 DEFUN ("garbage-collect", Fgarbage_collect, Sgarbage_collect, 0, 0, "",
5380 doc: /* Reclaim storage for Lisp objects no longer needed.
5381 Garbage collection happens automatically if you cons more than
5382 `gc-cons-threshold' bytes of Lisp data since previous garbage collection.
5383 `garbage-collect' normally returns a list with info on amount of space in use,
5384 where each entry has the form (NAME SIZE USED FREE), where:
5385 - NAME is a symbol describing the kind of objects this entry represents,
5386 - SIZE is the number of bytes used by each one,
5387 - USED is the number of those objects that were found live in the heap,
5388 - FREE is the number of those objects that are not live but that Emacs
5389 keeps around for future allocations (maybe because it does not know how
5390 to return them to the OS).
5391 However, if there was overflow in pure space, `garbage-collect'
5392 returns nil, because real GC can't be done.
5393 See Info node `(elisp)Garbage Collection'. */)
5394 (void)
5396 struct specbinding *bind;
5397 struct buffer *nextb;
5398 char stack_top_variable;
5399 ptrdiff_t i;
5400 bool message_p;
5401 ptrdiff_t count = SPECPDL_INDEX ();
5402 EMACS_TIME start;
5403 Lisp_Object retval = Qnil;
5405 if (abort_on_gc)
5406 abort ();
5408 /* Can't GC if pure storage overflowed because we can't determine
5409 if something is a pure object or not. */
5410 if (pure_bytes_used_before_overflow)
5411 return Qnil;
5413 check_cons_list ();
5415 /* Don't keep undo information around forever.
5416 Do this early on, so it is no problem if the user quits. */
5417 FOR_EACH_BUFFER (nextb)
5418 compact_buffer (nextb);
5420 start = current_emacs_time ();
5422 /* In case user calls debug_print during GC,
5423 don't let that cause a recursive GC. */
5424 consing_since_gc = 0;
5426 /* Save what's currently displayed in the echo area. */
5427 message_p = push_message ();
5428 record_unwind_protect (pop_message_unwind, Qnil);
5430 /* Save a copy of the contents of the stack, for debugging. */
5431 #if MAX_SAVE_STACK > 0
5432 if (NILP (Vpurify_flag))
5434 char *stack;
5435 ptrdiff_t stack_size;
5436 if (&stack_top_variable < stack_bottom)
5438 stack = &stack_top_variable;
5439 stack_size = stack_bottom - &stack_top_variable;
5441 else
5443 stack = stack_bottom;
5444 stack_size = &stack_top_variable - stack_bottom;
5446 if (stack_size <= MAX_SAVE_STACK)
5448 if (stack_copy_size < stack_size)
5450 stack_copy = xrealloc (stack_copy, stack_size);
5451 stack_copy_size = stack_size;
5453 memcpy (stack_copy, stack, stack_size);
5456 #endif /* MAX_SAVE_STACK > 0 */
5458 if (garbage_collection_messages)
5459 message1_nolog ("Garbage collecting...");
5461 BLOCK_INPUT;
5463 shrink_regexp_cache ();
5465 gc_in_progress = 1;
5467 /* Mark all the special slots that serve as the roots of accessibility. */
5469 for (i = 0; i < staticidx; i++)
5470 mark_object (*staticvec[i]);
5472 for (bind = specpdl; bind != specpdl_ptr; bind++)
5474 mark_object (bind->symbol);
5475 mark_object (bind->old_value);
5477 mark_terminals ();
5478 mark_kboards ();
5480 #ifdef USE_GTK
5482 extern void xg_mark_data (void);
5483 xg_mark_data ();
5485 #endif
5487 #if (GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS \
5488 || GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS)
5489 mark_stack ();
5490 #else
5492 register struct gcpro *tail;
5493 for (tail = gcprolist; tail; tail = tail->next)
5494 for (i = 0; i < tail->nvars; i++)
5495 mark_object (tail->var[i]);
5497 mark_byte_stack ();
5499 struct catchtag *catch;
5500 struct handler *handler;
5502 for (catch = catchlist; catch; catch = catch->next)
5504 mark_object (catch->tag);
5505 mark_object (catch->val);
5507 for (handler = handlerlist; handler; handler = handler->next)
5509 mark_object (handler->handler);
5510 mark_object (handler->var);
5513 mark_backtrace ();
5514 #endif
5516 #ifdef HAVE_WINDOW_SYSTEM
5517 mark_fringe_data ();
5518 #endif
5520 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5521 mark_stack ();
5522 #endif
5524 /* Everything is now marked, except for the things that require special
5525 finalization, i.e. the undo_list.
5526 Look thru every buffer's undo list
5527 for elements that update markers that were not marked,
5528 and delete them. */
5529 FOR_EACH_BUFFER (nextb)
5531 /* If a buffer's undo list is Qt, that means that undo is
5532 turned off in that buffer. Calling truncate_undo_list on
5533 Qt tends to return NULL, which effectively turns undo back on.
5534 So don't call truncate_undo_list if undo_list is Qt. */
5535 if (! EQ (nextb->INTERNAL_FIELD (undo_list), Qt))
5537 Lisp_Object tail, prev;
5538 tail = nextb->INTERNAL_FIELD (undo_list);
5539 prev = Qnil;
5540 while (CONSP (tail))
5542 if (CONSP (XCAR (tail))
5543 && MARKERP (XCAR (XCAR (tail)))
5544 && !XMARKER (XCAR (XCAR (tail)))->gcmarkbit)
5546 if (NILP (prev))
5547 nextb->INTERNAL_FIELD (undo_list) = tail = XCDR (tail);
5548 else
5550 tail = XCDR (tail);
5551 XSETCDR (prev, tail);
5554 else
5556 prev = tail;
5557 tail = XCDR (tail);
5561 /* Now that we have stripped the elements that need not be in the
5562 undo_list any more, we can finally mark the list. */
5563 mark_object (nextb->INTERNAL_FIELD (undo_list));
5566 gc_sweep ();
5568 /* Clear the mark bits that we set in certain root slots. */
5570 unmark_byte_stack ();
5571 VECTOR_UNMARK (&buffer_defaults);
5572 VECTOR_UNMARK (&buffer_local_symbols);
5574 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES && 0
5575 dump_zombies ();
5576 #endif
5578 UNBLOCK_INPUT;
5580 check_cons_list ();
5582 gc_in_progress = 0;
5584 consing_since_gc = 0;
5585 if (gc_cons_threshold < GC_DEFAULT_THRESHOLD / 10)
5586 gc_cons_threshold = GC_DEFAULT_THRESHOLD / 10;
5588 gc_relative_threshold = 0;
5589 if (FLOATP (Vgc_cons_percentage))
5590 { /* Set gc_cons_combined_threshold. */
5591 double tot = 0;
5593 tot += total_conses * sizeof (struct Lisp_Cons);
5594 tot += total_symbols * sizeof (struct Lisp_Symbol);
5595 tot += total_markers * sizeof (union Lisp_Misc);
5596 tot += total_string_bytes;
5597 tot += total_vector_slots * word_size;
5598 tot += total_floats * sizeof (struct Lisp_Float);
5599 tot += total_intervals * sizeof (struct interval);
5600 tot += total_strings * sizeof (struct Lisp_String);
5602 tot *= XFLOAT_DATA (Vgc_cons_percentage);
5603 if (0 < tot)
5605 if (tot < TYPE_MAXIMUM (EMACS_INT))
5606 gc_relative_threshold = tot;
5607 else
5608 gc_relative_threshold = TYPE_MAXIMUM (EMACS_INT);
5612 if (garbage_collection_messages)
5614 if (message_p || minibuf_level > 0)
5615 restore_message ();
5616 else
5617 message1_nolog ("Garbage collecting...done");
5620 unbind_to (count, Qnil);
5622 Lisp_Object total[11];
5623 int total_size = 10;
5625 total[0] = list4 (Qconses, make_number (sizeof (struct Lisp_Cons)),
5626 bounded_number (total_conses),
5627 bounded_number (total_free_conses));
5629 total[1] = list4 (Qsymbols, make_number (sizeof (struct Lisp_Symbol)),
5630 bounded_number (total_symbols),
5631 bounded_number (total_free_symbols));
5633 total[2] = list4 (Qmiscs, make_number (sizeof (union Lisp_Misc)),
5634 bounded_number (total_markers),
5635 bounded_number (total_free_markers));
5637 total[3] = list4 (Qstrings, make_number (sizeof (struct Lisp_String)),
5638 bounded_number (total_strings),
5639 bounded_number (total_free_strings));
5641 total[4] = list3 (Qstring_bytes, make_number (1),
5642 bounded_number (total_string_bytes));
5644 total[5] = list3 (Qvectors, make_number (sizeof (struct Lisp_Vector)),
5645 bounded_number (total_vectors));
5647 total[6] = list4 (Qvector_slots, make_number (word_size),
5648 bounded_number (total_vector_slots),
5649 bounded_number (total_free_vector_slots));
5651 total[7] = list4 (Qfloats, make_number (sizeof (struct Lisp_Float)),
5652 bounded_number (total_floats),
5653 bounded_number (total_free_floats));
5655 total[8] = list4 (Qintervals, make_number (sizeof (struct interval)),
5656 bounded_number (total_intervals),
5657 bounded_number (total_free_intervals));
5659 total[9] = list3 (Qbuffers, make_number (sizeof (struct buffer)),
5660 bounded_number (total_buffers));
5662 #ifdef DOUG_LEA_MALLOC
5663 total_size++;
5664 total[10] = list4 (Qheap, make_number (1024),
5665 bounded_number ((mallinfo ().uordblks + 1023) >> 10),
5666 bounded_number ((mallinfo ().fordblks + 1023) >> 10));
5667 #endif
5668 retval = Flist (total_size, total);
5671 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5673 /* Compute average percentage of zombies. */
5674 double nlive
5675 = (total_conses + total_symbols + total_markers + total_strings
5676 + total_vectors + total_floats + total_intervals + total_buffers);
5678 avg_live = (avg_live * ngcs + nlive) / (ngcs + 1);
5679 max_live = max (nlive, max_live);
5680 avg_zombies = (avg_zombies * ngcs + nzombies) / (ngcs + 1);
5681 max_zombies = max (nzombies, max_zombies);
5682 ++ngcs;
5684 #endif
5686 if (!NILP (Vpost_gc_hook))
5688 ptrdiff_t gc_count = inhibit_garbage_collection ();
5689 safe_run_hooks (Qpost_gc_hook);
5690 unbind_to (gc_count, Qnil);
5693 /* Accumulate statistics. */
5694 if (FLOATP (Vgc_elapsed))
5696 EMACS_TIME since_start = sub_emacs_time (current_emacs_time (), start);
5697 Vgc_elapsed = make_float (XFLOAT_DATA (Vgc_elapsed)
5698 + EMACS_TIME_TO_DOUBLE (since_start));
5701 gcs_done++;
5703 return retval;
5707 /* Mark Lisp objects in glyph matrix MATRIX. Currently the
5708 only interesting objects referenced from glyphs are strings. */
5710 static void
5711 mark_glyph_matrix (struct glyph_matrix *matrix)
5713 struct glyph_row *row = matrix->rows;
5714 struct glyph_row *end = row + matrix->nrows;
5716 for (; row < end; ++row)
5717 if (row->enabled_p)
5719 int area;
5720 for (area = LEFT_MARGIN_AREA; area < LAST_AREA; ++area)
5722 struct glyph *glyph = row->glyphs[area];
5723 struct glyph *end_glyph = glyph + row->used[area];
5725 for (; glyph < end_glyph; ++glyph)
5726 if (STRINGP (glyph->object)
5727 && !STRING_MARKED_P (XSTRING (glyph->object)))
5728 mark_object (glyph->object);
5734 /* Mark Lisp faces in the face cache C. */
5736 static void
5737 mark_face_cache (struct face_cache *c)
5739 if (c)
5741 int i, j;
5742 for (i = 0; i < c->used; ++i)
5744 struct face *face = FACE_FROM_ID (c->f, i);
5746 if (face)
5748 for (j = 0; j < LFACE_VECTOR_SIZE; ++j)
5749 mark_object (face->lface[j]);
5757 /* Mark reference to a Lisp_Object.
5758 If the object referred to has not been seen yet, recursively mark
5759 all the references contained in it. */
5761 #define LAST_MARKED_SIZE 500
5762 static Lisp_Object last_marked[LAST_MARKED_SIZE];
5763 static int last_marked_index;
5765 /* For debugging--call abort when we cdr down this many
5766 links of a list, in mark_object. In debugging,
5767 the call to abort will hit a breakpoint.
5768 Normally this is zero and the check never goes off. */
5769 ptrdiff_t mark_object_loop_halt EXTERNALLY_VISIBLE;
5771 static void
5772 mark_vectorlike (struct Lisp_Vector *ptr)
5774 ptrdiff_t size = ptr->header.size;
5775 ptrdiff_t i;
5777 eassert (!VECTOR_MARKED_P (ptr));
5778 VECTOR_MARK (ptr); /* Else mark it. */
5779 if (size & PSEUDOVECTOR_FLAG)
5780 size &= PSEUDOVECTOR_SIZE_MASK;
5782 /* Note that this size is not the memory-footprint size, but only
5783 the number of Lisp_Object fields that we should trace.
5784 The distinction is used e.g. by Lisp_Process which places extra
5785 non-Lisp_Object fields at the end of the structure... */
5786 for (i = 0; i < size; i++) /* ...and then mark its elements. */
5787 mark_object (ptr->contents[i]);
5790 /* Like mark_vectorlike but optimized for char-tables (and
5791 sub-char-tables) assuming that the contents are mostly integers or
5792 symbols. */
5794 static void
5795 mark_char_table (struct Lisp_Vector *ptr)
5797 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
5798 int i;
5800 eassert (!VECTOR_MARKED_P (ptr));
5801 VECTOR_MARK (ptr);
5802 for (i = 0; i < size; i++)
5804 Lisp_Object val = ptr->contents[i];
5806 if (INTEGERP (val) || (SYMBOLP (val) && XSYMBOL (val)->gcmarkbit))
5807 continue;
5808 if (SUB_CHAR_TABLE_P (val))
5810 if (! VECTOR_MARKED_P (XVECTOR (val)))
5811 mark_char_table (XVECTOR (val));
5813 else
5814 mark_object (val);
5818 /* Mark the chain of overlays starting at PTR. */
5820 static void
5821 mark_overlay (struct Lisp_Overlay *ptr)
5823 for (; ptr && !ptr->gcmarkbit; ptr = ptr->next)
5825 ptr->gcmarkbit = 1;
5826 mark_object (ptr->start);
5827 mark_object (ptr->end);
5828 mark_object (ptr->plist);
5832 /* Mark Lisp_Objects and special pointers in BUFFER. */
5834 static void
5835 mark_buffer (struct buffer *buffer)
5837 /* This is handled much like other pseudovectors... */
5838 mark_vectorlike ((struct Lisp_Vector *) buffer);
5840 /* ...but there are some buffer-specific things. */
5842 MARK_INTERVAL_TREE (buffer_intervals (buffer));
5844 /* For now, we just don't mark the undo_list. It's done later in
5845 a special way just before the sweep phase, and after stripping
5846 some of its elements that are not needed any more. */
5848 mark_overlay (buffer->overlays_before);
5849 mark_overlay (buffer->overlays_after);
5851 /* If this is an indirect buffer, mark its base buffer. */
5852 if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))
5853 mark_buffer (buffer->base_buffer);
5856 /* Determine type of generic Lisp_Object and mark it accordingly. */
5858 void
5859 mark_object (Lisp_Object arg)
5861 register Lisp_Object obj = arg;
5862 #ifdef GC_CHECK_MARKED_OBJECTS
5863 void *po;
5864 struct mem_node *m;
5865 #endif
5866 ptrdiff_t cdr_count = 0;
5868 loop:
5870 if (PURE_POINTER_P (XPNTR (obj)))
5871 return;
5873 last_marked[last_marked_index++] = obj;
5874 if (last_marked_index == LAST_MARKED_SIZE)
5875 last_marked_index = 0;
5877 /* Perform some sanity checks on the objects marked here. Abort if
5878 we encounter an object we know is bogus. This increases GC time
5879 by ~80%, and requires compilation with GC_MARK_STACK != 0. */
5880 #ifdef GC_CHECK_MARKED_OBJECTS
5882 po = (void *) XPNTR (obj);
5884 /* Check that the object pointed to by PO is known to be a Lisp
5885 structure allocated from the heap. */
5886 #define CHECK_ALLOCATED() \
5887 do { \
5888 m = mem_find (po); \
5889 if (m == MEM_NIL) \
5890 abort (); \
5891 } while (0)
5893 /* Check that the object pointed to by PO is live, using predicate
5894 function LIVEP. */
5895 #define CHECK_LIVE(LIVEP) \
5896 do { \
5897 if (!LIVEP (m, po)) \
5898 abort (); \
5899 } while (0)
5901 /* Check both of the above conditions. */
5902 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) \
5903 do { \
5904 CHECK_ALLOCATED (); \
5905 CHECK_LIVE (LIVEP); \
5906 } while (0) \
5908 #else /* not GC_CHECK_MARKED_OBJECTS */
5910 #define CHECK_LIVE(LIVEP) (void) 0
5911 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) (void) 0
5913 #endif /* not GC_CHECK_MARKED_OBJECTS */
5915 switch (XTYPE (obj))
5917 case Lisp_String:
5919 register struct Lisp_String *ptr = XSTRING (obj);
5920 if (STRING_MARKED_P (ptr))
5921 break;
5922 CHECK_ALLOCATED_AND_LIVE (live_string_p);
5923 MARK_STRING (ptr);
5924 MARK_INTERVAL_TREE (ptr->intervals);
5925 #ifdef GC_CHECK_STRING_BYTES
5926 /* Check that the string size recorded in the string is the
5927 same as the one recorded in the sdata structure. */
5928 string_bytes (ptr);
5929 #endif /* GC_CHECK_STRING_BYTES */
5931 break;
5933 case Lisp_Vectorlike:
5935 register struct Lisp_Vector *ptr = XVECTOR (obj);
5936 register ptrdiff_t pvectype;
5938 if (VECTOR_MARKED_P (ptr))
5939 break;
5941 #ifdef GC_CHECK_MARKED_OBJECTS
5942 m = mem_find (po);
5943 if (m == MEM_NIL && !SUBRP (obj)
5944 && po != &buffer_defaults
5945 && po != &buffer_local_symbols)
5946 abort ();
5947 #endif /* GC_CHECK_MARKED_OBJECTS */
5949 if (ptr->header.size & PSEUDOVECTOR_FLAG)
5950 pvectype = ((ptr->header.size & PVEC_TYPE_MASK)
5951 >> PSEUDOVECTOR_SIZE_BITS);
5952 else
5953 pvectype = 0;
5955 if (pvectype != PVEC_SUBR && pvectype != PVEC_BUFFER)
5956 CHECK_LIVE (live_vector_p);
5958 switch (pvectype)
5960 case PVEC_BUFFER:
5961 #ifdef GC_CHECK_MARKED_OBJECTS
5962 if (po != &buffer_defaults && po != &buffer_local_symbols)
5964 struct buffer *b;
5965 FOR_EACH_BUFFER (b)
5966 if (b == po)
5967 break;
5968 if (b == NULL)
5969 abort ();
5971 #endif /* GC_CHECK_MARKED_OBJECTS */
5972 mark_buffer ((struct buffer *) ptr);
5973 break;
5975 case PVEC_COMPILED:
5976 { /* We could treat this just like a vector, but it is better
5977 to save the COMPILED_CONSTANTS element for last and avoid
5978 recursion there. */
5979 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
5980 int i;
5982 VECTOR_MARK (ptr);
5983 for (i = 0; i < size; i++)
5984 if (i != COMPILED_CONSTANTS)
5985 mark_object (ptr->contents[i]);
5986 if (size > COMPILED_CONSTANTS)
5988 obj = ptr->contents[COMPILED_CONSTANTS];
5989 goto loop;
5992 break;
5994 case PVEC_FRAME:
5996 mark_vectorlike (ptr);
5997 mark_face_cache (((struct frame *) ptr)->face_cache);
5999 break;
6001 case PVEC_WINDOW:
6003 struct window *w = (struct window *) ptr;
6005 mark_vectorlike (ptr);
6006 /* Mark glyphs for leaf windows. Marking window
6007 matrices is sufficient because frame matrices
6008 use the same glyph memory. */
6009 if (NILP (w->hchild) && NILP (w->vchild)
6010 && w->current_matrix)
6012 mark_glyph_matrix (w->current_matrix);
6013 mark_glyph_matrix (w->desired_matrix);
6016 break;
6018 case PVEC_HASH_TABLE:
6020 struct Lisp_Hash_Table *h = (struct Lisp_Hash_Table *) ptr;
6022 mark_vectorlike (ptr);
6023 /* If hash table is not weak, mark all keys and values.
6024 For weak tables, mark only the vector. */
6025 if (NILP (h->weak))
6026 mark_object (h->key_and_value);
6027 else
6028 VECTOR_MARK (XVECTOR (h->key_and_value));
6030 break;
6032 case PVEC_CHAR_TABLE:
6033 mark_char_table (ptr);
6034 break;
6036 case PVEC_BOOL_VECTOR:
6037 /* No Lisp_Objects to mark in a bool vector. */
6038 VECTOR_MARK (ptr);
6039 break;
6041 case PVEC_SUBR:
6042 break;
6044 case PVEC_FREE:
6045 abort ();
6047 default:
6048 mark_vectorlike (ptr);
6051 break;
6053 case Lisp_Symbol:
6055 register struct Lisp_Symbol *ptr = XSYMBOL (obj);
6056 struct Lisp_Symbol *ptrx;
6058 if (ptr->gcmarkbit)
6059 break;
6060 CHECK_ALLOCATED_AND_LIVE (live_symbol_p);
6061 ptr->gcmarkbit = 1;
6062 mark_object (ptr->function);
6063 mark_object (ptr->plist);
6064 switch (ptr->redirect)
6066 case SYMBOL_PLAINVAL: mark_object (SYMBOL_VAL (ptr)); break;
6067 case SYMBOL_VARALIAS:
6069 Lisp_Object tem;
6070 XSETSYMBOL (tem, SYMBOL_ALIAS (ptr));
6071 mark_object (tem);
6072 break;
6074 case SYMBOL_LOCALIZED:
6076 struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr);
6077 /* If the value is forwarded to a buffer or keyboard field,
6078 these are marked when we see the corresponding object.
6079 And if it's forwarded to a C variable, either it's not
6080 a Lisp_Object var, or it's staticpro'd already. */
6081 mark_object (blv->where);
6082 mark_object (blv->valcell);
6083 mark_object (blv->defcell);
6084 break;
6086 case SYMBOL_FORWARDED:
6087 /* If the value is forwarded to a buffer or keyboard field,
6088 these are marked when we see the corresponding object.
6089 And if it's forwarded to a C variable, either it's not
6090 a Lisp_Object var, or it's staticpro'd already. */
6091 break;
6092 default: abort ();
6094 if (!PURE_POINTER_P (XSTRING (ptr->name)))
6095 MARK_STRING (XSTRING (ptr->name));
6096 MARK_INTERVAL_TREE (string_intervals (ptr->name));
6098 ptr = ptr->next;
6099 if (ptr)
6101 ptrx = ptr; /* Use of ptrx avoids compiler bug on Sun. */
6102 XSETSYMBOL (obj, ptrx);
6103 goto loop;
6106 break;
6108 case Lisp_Misc:
6109 CHECK_ALLOCATED_AND_LIVE (live_misc_p);
6111 if (XMISCANY (obj)->gcmarkbit)
6112 break;
6114 switch (XMISCTYPE (obj))
6116 case Lisp_Misc_Marker:
6117 /* DO NOT mark thru the marker's chain.
6118 The buffer's markers chain does not preserve markers from gc;
6119 instead, markers are removed from the chain when freed by gc. */
6120 XMISCANY (obj)->gcmarkbit = 1;
6121 break;
6123 case Lisp_Misc_Save_Value:
6124 XMISCANY (obj)->gcmarkbit = 1;
6125 #if GC_MARK_STACK
6127 register struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
6128 /* If DOGC is set, POINTER is the address of a memory
6129 area containing INTEGER potential Lisp_Objects. */
6130 if (ptr->dogc)
6132 Lisp_Object *p = (Lisp_Object *) ptr->pointer;
6133 ptrdiff_t nelt;
6134 for (nelt = ptr->integer; nelt > 0; nelt--, p++)
6135 mark_maybe_object (*p);
6138 #endif
6139 break;
6141 case Lisp_Misc_Overlay:
6142 mark_overlay (XOVERLAY (obj));
6143 break;
6145 default:
6146 abort ();
6148 break;
6150 case Lisp_Cons:
6152 register struct Lisp_Cons *ptr = XCONS (obj);
6153 if (CONS_MARKED_P (ptr))
6154 break;
6155 CHECK_ALLOCATED_AND_LIVE (live_cons_p);
6156 CONS_MARK (ptr);
6157 /* If the cdr is nil, avoid recursion for the car. */
6158 if (EQ (ptr->u.cdr, Qnil))
6160 obj = ptr->car;
6161 cdr_count = 0;
6162 goto loop;
6164 mark_object (ptr->car);
6165 obj = ptr->u.cdr;
6166 cdr_count++;
6167 if (cdr_count == mark_object_loop_halt)
6168 abort ();
6169 goto loop;
6172 case Lisp_Float:
6173 CHECK_ALLOCATED_AND_LIVE (live_float_p);
6174 FLOAT_MARK (XFLOAT (obj));
6175 break;
6177 case_Lisp_Int:
6178 break;
6180 default:
6181 abort ();
6184 #undef CHECK_LIVE
6185 #undef CHECK_ALLOCATED
6186 #undef CHECK_ALLOCATED_AND_LIVE
6188 /* Mark the Lisp pointers in the terminal objects.
6189 Called by Fgarbage_collect. */
6191 static void
6192 mark_terminals (void)
6194 struct terminal *t;
6195 for (t = terminal_list; t; t = t->next_terminal)
6197 eassert (t->name != NULL);
6198 #ifdef HAVE_WINDOW_SYSTEM
6199 /* If a terminal object is reachable from a stacpro'ed object,
6200 it might have been marked already. Make sure the image cache
6201 gets marked. */
6202 mark_image_cache (t->image_cache);
6203 #endif /* HAVE_WINDOW_SYSTEM */
6204 if (!VECTOR_MARKED_P (t))
6205 mark_vectorlike ((struct Lisp_Vector *)t);
6211 /* Value is non-zero if OBJ will survive the current GC because it's
6212 either marked or does not need to be marked to survive. */
6214 bool
6215 survives_gc_p (Lisp_Object obj)
6217 bool survives_p;
6219 switch (XTYPE (obj))
6221 case_Lisp_Int:
6222 survives_p = 1;
6223 break;
6225 case Lisp_Symbol:
6226 survives_p = XSYMBOL (obj)->gcmarkbit;
6227 break;
6229 case Lisp_Misc:
6230 survives_p = XMISCANY (obj)->gcmarkbit;
6231 break;
6233 case Lisp_String:
6234 survives_p = STRING_MARKED_P (XSTRING (obj));
6235 break;
6237 case Lisp_Vectorlike:
6238 survives_p = SUBRP (obj) || VECTOR_MARKED_P (XVECTOR (obj));
6239 break;
6241 case Lisp_Cons:
6242 survives_p = CONS_MARKED_P (XCONS (obj));
6243 break;
6245 case Lisp_Float:
6246 survives_p = FLOAT_MARKED_P (XFLOAT (obj));
6247 break;
6249 default:
6250 abort ();
6253 return survives_p || PURE_POINTER_P ((void *) XPNTR (obj));
6258 /* Sweep: find all structures not marked, and free them. */
6260 static void
6261 gc_sweep (void)
6263 /* Remove or mark entries in weak hash tables.
6264 This must be done before any object is unmarked. */
6265 sweep_weak_hash_tables ();
6267 sweep_strings ();
6268 check_string_bytes (!noninteractive);
6270 /* Put all unmarked conses on free list */
6272 register struct cons_block *cblk;
6273 struct cons_block **cprev = &cons_block;
6274 register int lim = cons_block_index;
6275 EMACS_INT num_free = 0, num_used = 0;
6277 cons_free_list = 0;
6279 for (cblk = cons_block; cblk; cblk = *cprev)
6281 register int i = 0;
6282 int this_free = 0;
6283 int ilim = (lim + BITS_PER_INT - 1) / BITS_PER_INT;
6285 /* Scan the mark bits an int at a time. */
6286 for (i = 0; i < ilim; i++)
6288 if (cblk->gcmarkbits[i] == -1)
6290 /* Fast path - all cons cells for this int are marked. */
6291 cblk->gcmarkbits[i] = 0;
6292 num_used += BITS_PER_INT;
6294 else
6296 /* Some cons cells for this int are not marked.
6297 Find which ones, and free them. */
6298 int start, pos, stop;
6300 start = i * BITS_PER_INT;
6301 stop = lim - start;
6302 if (stop > BITS_PER_INT)
6303 stop = BITS_PER_INT;
6304 stop += start;
6306 for (pos = start; pos < stop; pos++)
6308 if (!CONS_MARKED_P (&cblk->conses[pos]))
6310 this_free++;
6311 cblk->conses[pos].u.chain = cons_free_list;
6312 cons_free_list = &cblk->conses[pos];
6313 #if GC_MARK_STACK
6314 cons_free_list->car = Vdead;
6315 #endif
6317 else
6319 num_used++;
6320 CONS_UNMARK (&cblk->conses[pos]);
6326 lim = CONS_BLOCK_SIZE;
6327 /* If this block contains only free conses and we have already
6328 seen more than two blocks worth of free conses then deallocate
6329 this block. */
6330 if (this_free == CONS_BLOCK_SIZE && num_free > CONS_BLOCK_SIZE)
6332 *cprev = cblk->next;
6333 /* Unhook from the free list. */
6334 cons_free_list = cblk->conses[0].u.chain;
6335 lisp_align_free (cblk);
6337 else
6339 num_free += this_free;
6340 cprev = &cblk->next;
6343 total_conses = num_used;
6344 total_free_conses = num_free;
6347 /* Put all unmarked floats on free list */
6349 register struct float_block *fblk;
6350 struct float_block **fprev = &float_block;
6351 register int lim = float_block_index;
6352 EMACS_INT num_free = 0, num_used = 0;
6354 float_free_list = 0;
6356 for (fblk = float_block; fblk; fblk = *fprev)
6358 register int i;
6359 int this_free = 0;
6360 for (i = 0; i < lim; i++)
6361 if (!FLOAT_MARKED_P (&fblk->floats[i]))
6363 this_free++;
6364 fblk->floats[i].u.chain = float_free_list;
6365 float_free_list = &fblk->floats[i];
6367 else
6369 num_used++;
6370 FLOAT_UNMARK (&fblk->floats[i]);
6372 lim = FLOAT_BLOCK_SIZE;
6373 /* If this block contains only free floats and we have already
6374 seen more than two blocks worth of free floats then deallocate
6375 this block. */
6376 if (this_free == FLOAT_BLOCK_SIZE && num_free > FLOAT_BLOCK_SIZE)
6378 *fprev = fblk->next;
6379 /* Unhook from the free list. */
6380 float_free_list = fblk->floats[0].u.chain;
6381 lisp_align_free (fblk);
6383 else
6385 num_free += this_free;
6386 fprev = &fblk->next;
6389 total_floats = num_used;
6390 total_free_floats = num_free;
6393 /* Put all unmarked intervals on free list */
6395 register struct interval_block *iblk;
6396 struct interval_block **iprev = &interval_block;
6397 register int lim = interval_block_index;
6398 EMACS_INT num_free = 0, num_used = 0;
6400 interval_free_list = 0;
6402 for (iblk = interval_block; iblk; iblk = *iprev)
6404 register int i;
6405 int this_free = 0;
6407 for (i = 0; i < lim; i++)
6409 if (!iblk->intervals[i].gcmarkbit)
6411 set_interval_parent (&iblk->intervals[i], interval_free_list);
6412 interval_free_list = &iblk->intervals[i];
6413 this_free++;
6415 else
6417 num_used++;
6418 iblk->intervals[i].gcmarkbit = 0;
6421 lim = INTERVAL_BLOCK_SIZE;
6422 /* If this block contains only free intervals and we have already
6423 seen more than two blocks worth of free intervals then
6424 deallocate this block. */
6425 if (this_free == INTERVAL_BLOCK_SIZE && num_free > INTERVAL_BLOCK_SIZE)
6427 *iprev = iblk->next;
6428 /* Unhook from the free list. */
6429 interval_free_list = INTERVAL_PARENT (&iblk->intervals[0]);
6430 lisp_free (iblk);
6432 else
6434 num_free += this_free;
6435 iprev = &iblk->next;
6438 total_intervals = num_used;
6439 total_free_intervals = num_free;
6442 /* Put all unmarked symbols on free list */
6444 register struct symbol_block *sblk;
6445 struct symbol_block **sprev = &symbol_block;
6446 register int lim = symbol_block_index;
6447 EMACS_INT num_free = 0, num_used = 0;
6449 symbol_free_list = NULL;
6451 for (sblk = symbol_block; sblk; sblk = *sprev)
6453 int this_free = 0;
6454 union aligned_Lisp_Symbol *sym = sblk->symbols;
6455 union aligned_Lisp_Symbol *end = sym + lim;
6457 for (; sym < end; ++sym)
6459 /* Check if the symbol was created during loadup. In such a case
6460 it might be pointed to by pure bytecode which we don't trace,
6461 so we conservatively assume that it is live. */
6462 bool pure_p = PURE_POINTER_P (XSTRING (sym->s.name));
6464 if (!sym->s.gcmarkbit && !pure_p)
6466 if (sym->s.redirect == SYMBOL_LOCALIZED)
6467 xfree (SYMBOL_BLV (&sym->s));
6468 sym->s.next = symbol_free_list;
6469 symbol_free_list = &sym->s;
6470 #if GC_MARK_STACK
6471 symbol_free_list->function = Vdead;
6472 #endif
6473 ++this_free;
6475 else
6477 ++num_used;
6478 if (!pure_p)
6479 UNMARK_STRING (XSTRING (sym->s.name));
6480 sym->s.gcmarkbit = 0;
6484 lim = SYMBOL_BLOCK_SIZE;
6485 /* If this block contains only free symbols and we have already
6486 seen more than two blocks worth of free symbols then deallocate
6487 this block. */
6488 if (this_free == SYMBOL_BLOCK_SIZE && num_free > SYMBOL_BLOCK_SIZE)
6490 *sprev = sblk->next;
6491 /* Unhook from the free list. */
6492 symbol_free_list = sblk->symbols[0].s.next;
6493 lisp_free (sblk);
6495 else
6497 num_free += this_free;
6498 sprev = &sblk->next;
6501 total_symbols = num_used;
6502 total_free_symbols = num_free;
6505 /* Put all unmarked misc's on free list.
6506 For a marker, first unchain it from the buffer it points into. */
6508 register struct marker_block *mblk;
6509 struct marker_block **mprev = &marker_block;
6510 register int lim = marker_block_index;
6511 EMACS_INT num_free = 0, num_used = 0;
6513 marker_free_list = 0;
6515 for (mblk = marker_block; mblk; mblk = *mprev)
6517 register int i;
6518 int this_free = 0;
6520 for (i = 0; i < lim; i++)
6522 if (!mblk->markers[i].m.u_any.gcmarkbit)
6524 if (mblk->markers[i].m.u_any.type == Lisp_Misc_Marker)
6525 unchain_marker (&mblk->markers[i].m.u_marker);
6526 /* Set the type of the freed object to Lisp_Misc_Free.
6527 We could leave the type alone, since nobody checks it,
6528 but this might catch bugs faster. */
6529 mblk->markers[i].m.u_marker.type = Lisp_Misc_Free;
6530 mblk->markers[i].m.u_free.chain = marker_free_list;
6531 marker_free_list = &mblk->markers[i].m;
6532 this_free++;
6534 else
6536 num_used++;
6537 mblk->markers[i].m.u_any.gcmarkbit = 0;
6540 lim = MARKER_BLOCK_SIZE;
6541 /* If this block contains only free markers and we have already
6542 seen more than two blocks worth of free markers then deallocate
6543 this block. */
6544 if (this_free == MARKER_BLOCK_SIZE && num_free > MARKER_BLOCK_SIZE)
6546 *mprev = mblk->next;
6547 /* Unhook from the free list. */
6548 marker_free_list = mblk->markers[0].m.u_free.chain;
6549 lisp_free (mblk);
6551 else
6553 num_free += this_free;
6554 mprev = &mblk->next;
6558 total_markers = num_used;
6559 total_free_markers = num_free;
6562 /* Free all unmarked buffers */
6564 register struct buffer *buffer = all_buffers, *prev = 0, *next;
6566 total_buffers = 0;
6567 while (buffer)
6568 if (!VECTOR_MARKED_P (buffer))
6570 if (prev)
6571 prev->header.next = buffer->header.next;
6572 else
6573 all_buffers = buffer->header.next.buffer;
6574 next = buffer->header.next.buffer;
6575 lisp_free (buffer);
6576 buffer = next;
6578 else
6580 VECTOR_UNMARK (buffer);
6581 /* Do not use buffer_(set|get)_intervals here. */
6582 buffer->text->intervals = balance_intervals (buffer->text->intervals);
6583 total_buffers++;
6584 prev = buffer, buffer = buffer->header.next.buffer;
6588 sweep_vectors ();
6589 check_string_bytes (!noninteractive);
6595 /* Debugging aids. */
6597 DEFUN ("memory-limit", Fmemory_limit, Smemory_limit, 0, 0, 0,
6598 doc: /* Return the address of the last byte Emacs has allocated, divided by 1024.
6599 This may be helpful in debugging Emacs's memory usage.
6600 We divide the value by 1024 to make sure it fits in a Lisp integer. */)
6601 (void)
6603 Lisp_Object end;
6605 XSETINT (end, (intptr_t) (char *) sbrk (0) / 1024);
6607 return end;
6610 DEFUN ("memory-use-counts", Fmemory_use_counts, Smemory_use_counts, 0, 0, 0,
6611 doc: /* Return a list of counters that measure how much consing there has been.
6612 Each of these counters increments for a certain kind of object.
6613 The counters wrap around from the largest positive integer to zero.
6614 Garbage collection does not decrease them.
6615 The elements of the value are as follows:
6616 (CONSES FLOATS VECTOR-CELLS SYMBOLS STRING-CHARS MISCS INTERVALS STRINGS)
6617 All are in units of 1 = one object consed
6618 except for VECTOR-CELLS and STRING-CHARS, which count the total length of
6619 objects consed.
6620 MISCS include overlays, markers, and some internal types.
6621 Frames, windows, buffers, and subprocesses count as vectors
6622 (but the contents of a buffer's text do not count here). */)
6623 (void)
6625 return listn (CONSTYPE_HEAP, 8,
6626 bounded_number (cons_cells_consed),
6627 bounded_number (floats_consed),
6628 bounded_number (vector_cells_consed),
6629 bounded_number (symbols_consed),
6630 bounded_number (string_chars_consed),
6631 bounded_number (misc_objects_consed),
6632 bounded_number (intervals_consed),
6633 bounded_number (strings_consed));
6636 /* Find at most FIND_MAX symbols which have OBJ as their value or
6637 function. This is used in gdbinit's `xwhichsymbols' command. */
6639 Lisp_Object
6640 which_symbols (Lisp_Object obj, EMACS_INT find_max)
6642 struct symbol_block *sblk;
6643 ptrdiff_t gc_count = inhibit_garbage_collection ();
6644 Lisp_Object found = Qnil;
6646 if (! DEADP (obj))
6648 for (sblk = symbol_block; sblk; sblk = sblk->next)
6650 union aligned_Lisp_Symbol *aligned_sym = sblk->symbols;
6651 int bn;
6653 for (bn = 0; bn < SYMBOL_BLOCK_SIZE; bn++, aligned_sym++)
6655 struct Lisp_Symbol *sym = &aligned_sym->s;
6656 Lisp_Object val;
6657 Lisp_Object tem;
6659 if (sblk == symbol_block && bn >= symbol_block_index)
6660 break;
6662 XSETSYMBOL (tem, sym);
6663 val = find_symbol_value (tem);
6664 if (EQ (val, obj)
6665 || EQ (sym->function, obj)
6666 || (!NILP (sym->function)
6667 && COMPILEDP (sym->function)
6668 && EQ (AREF (sym->function, COMPILED_BYTECODE), obj))
6669 || (!NILP (val)
6670 && COMPILEDP (val)
6671 && EQ (AREF (val, COMPILED_BYTECODE), obj)))
6673 found = Fcons (tem, found);
6674 if (--find_max == 0)
6675 goto out;
6681 out:
6682 unbind_to (gc_count, Qnil);
6683 return found;
6686 #ifdef ENABLE_CHECKING
6688 # include <execinfo.h>
6690 bool suppress_checking;
6692 void
6693 die (const char *msg, const char *file, int line)
6695 enum { NPOINTERS_MAX = 500 };
6696 void *buffer[NPOINTERS_MAX];
6697 int npointers;
6698 fprintf (stderr, "\r\n%s:%d: Emacs fatal error: %s\r\n",
6699 file, line, msg);
6700 npointers = backtrace (buffer, NPOINTERS_MAX);
6701 backtrace_symbols_fd (buffer, npointers, STDERR_FILENO);
6702 abort ();
6704 #endif
6706 /* Initialization */
6708 void
6709 init_alloc_once (void)
6711 /* Used to do Vpurify_flag = Qt here, but Qt isn't set up yet! */
6712 purebeg = PUREBEG;
6713 pure_size = PURESIZE;
6715 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
6716 mem_init ();
6717 Vdead = make_pure_string ("DEAD", 4, 4, 0);
6718 #endif
6720 #ifdef DOUG_LEA_MALLOC
6721 mallopt (M_TRIM_THRESHOLD, 128*1024); /* trim threshold */
6722 mallopt (M_MMAP_THRESHOLD, 64*1024); /* mmap threshold */
6723 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS); /* max. number of mmap'ed areas */
6724 #endif
6725 init_strings ();
6726 init_vectors ();
6728 #ifdef REL_ALLOC
6729 malloc_hysteresis = 32;
6730 #else
6731 malloc_hysteresis = 0;
6732 #endif
6734 refill_memory_reserve ();
6735 gc_cons_threshold = GC_DEFAULT_THRESHOLD;
6738 void
6739 init_alloc (void)
6741 gcprolist = 0;
6742 byte_stack_list = 0;
6743 #if GC_MARK_STACK
6744 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
6745 setjmp_tested_p = longjmps_done = 0;
6746 #endif
6747 #endif
6748 Vgc_elapsed = make_float (0.0);
6749 gcs_done = 0;
6752 void
6753 syms_of_alloc (void)
6755 DEFVAR_INT ("gc-cons-threshold", gc_cons_threshold,
6756 doc: /* Number of bytes of consing between garbage collections.
6757 Garbage collection can happen automatically once this many bytes have been
6758 allocated since the last garbage collection. All data types count.
6760 Garbage collection happens automatically only when `eval' is called.
6762 By binding this temporarily to a large number, you can effectively
6763 prevent garbage collection during a part of the program.
6764 See also `gc-cons-percentage'. */);
6766 DEFVAR_LISP ("gc-cons-percentage", Vgc_cons_percentage,
6767 doc: /* Portion of the heap used for allocation.
6768 Garbage collection can happen automatically once this portion of the heap
6769 has been allocated since the last garbage collection.
6770 If this portion is smaller than `gc-cons-threshold', this is ignored. */);
6771 Vgc_cons_percentage = make_float (0.1);
6773 DEFVAR_INT ("pure-bytes-used", pure_bytes_used,
6774 doc: /* Number of bytes of shareable Lisp data allocated so far. */);
6776 DEFVAR_INT ("cons-cells-consed", cons_cells_consed,
6777 doc: /* Number of cons cells that have been consed so far. */);
6779 DEFVAR_INT ("floats-consed", floats_consed,
6780 doc: /* Number of floats that have been consed so far. */);
6782 DEFVAR_INT ("vector-cells-consed", vector_cells_consed,
6783 doc: /* Number of vector cells that have been consed so far. */);
6785 DEFVAR_INT ("symbols-consed", symbols_consed,
6786 doc: /* Number of symbols that have been consed so far. */);
6788 DEFVAR_INT ("string-chars-consed", string_chars_consed,
6789 doc: /* Number of string characters that have been consed so far. */);
6791 DEFVAR_INT ("misc-objects-consed", misc_objects_consed,
6792 doc: /* Number of miscellaneous objects that have been consed so far.
6793 These include markers and overlays, plus certain objects not visible
6794 to users. */);
6796 DEFVAR_INT ("intervals-consed", intervals_consed,
6797 doc: /* Number of intervals that have been consed so far. */);
6799 DEFVAR_INT ("strings-consed", strings_consed,
6800 doc: /* Number of strings that have been consed so far. */);
6802 DEFVAR_LISP ("purify-flag", Vpurify_flag,
6803 doc: /* Non-nil means loading Lisp code in order to dump an executable.
6804 This means that certain objects should be allocated in shared (pure) space.
6805 It can also be set to a hash-table, in which case this table is used to
6806 do hash-consing of the objects allocated to pure space. */);
6808 DEFVAR_BOOL ("garbage-collection-messages", garbage_collection_messages,
6809 doc: /* Non-nil means display messages at start and end of garbage collection. */);
6810 garbage_collection_messages = 0;
6812 DEFVAR_LISP ("post-gc-hook", Vpost_gc_hook,
6813 doc: /* Hook run after garbage collection has finished. */);
6814 Vpost_gc_hook = Qnil;
6815 DEFSYM (Qpost_gc_hook, "post-gc-hook");
6817 DEFVAR_LISP ("memory-signal-data", Vmemory_signal_data,
6818 doc: /* Precomputed `signal' argument for memory-full error. */);
6819 /* We build this in advance because if we wait until we need it, we might
6820 not be able to allocate the memory to hold it. */
6821 Vmemory_signal_data
6822 = listn (CONSTYPE_PURE, 2, Qerror,
6823 build_pure_c_string ("Memory exhausted--use M-x save-some-buffers then exit and restart Emacs"));
6825 DEFVAR_LISP ("memory-full", Vmemory_full,
6826 doc: /* Non-nil means Emacs cannot get much more Lisp memory. */);
6827 Vmemory_full = Qnil;
6829 DEFSYM (Qconses, "conses");
6830 DEFSYM (Qsymbols, "symbols");
6831 DEFSYM (Qmiscs, "miscs");
6832 DEFSYM (Qstrings, "strings");
6833 DEFSYM (Qvectors, "vectors");
6834 DEFSYM (Qfloats, "floats");
6835 DEFSYM (Qintervals, "intervals");
6836 DEFSYM (Qbuffers, "buffers");
6837 DEFSYM (Qstring_bytes, "string-bytes");
6838 DEFSYM (Qvector_slots, "vector-slots");
6839 DEFSYM (Qheap, "heap");
6841 DEFSYM (Qgc_cons_threshold, "gc-cons-threshold");
6842 DEFSYM (Qchar_table_extra_slots, "char-table-extra-slots");
6844 DEFVAR_LISP ("gc-elapsed", Vgc_elapsed,
6845 doc: /* Accumulated time elapsed in garbage collections.
6846 The time is in seconds as a floating point value. */);
6847 DEFVAR_INT ("gcs-done", gcs_done,
6848 doc: /* Accumulated number of garbage collections done. */);
6850 defsubr (&Scons);
6851 defsubr (&Slist);
6852 defsubr (&Svector);
6853 defsubr (&Smake_byte_code);
6854 defsubr (&Smake_list);
6855 defsubr (&Smake_vector);
6856 defsubr (&Smake_string);
6857 defsubr (&Smake_bool_vector);
6858 defsubr (&Smake_symbol);
6859 defsubr (&Smake_marker);
6860 defsubr (&Spurecopy);
6861 defsubr (&Sgarbage_collect);
6862 defsubr (&Smemory_limit);
6863 defsubr (&Smemory_use_counts);
6865 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
6866 defsubr (&Sgc_status);
6867 #endif
6870 /* When compiled with GCC, GDB might say "No enum type named
6871 pvec_type" if we don't have at least one symbol with that type, and
6872 then xbacktrace could fail. Similarly for the other enums and
6873 their values. */
6874 union
6876 enum CHARTAB_SIZE_BITS CHARTAB_SIZE_BITS;
6877 enum CHAR_TABLE_STANDARD_SLOTS CHAR_TABLE_STANDARD_SLOTS;
6878 enum char_bits char_bits;
6879 enum CHECK_LISP_OBJECT_TYPE CHECK_LISP_OBJECT_TYPE;
6880 enum DEFAULT_HASH_SIZE DEFAULT_HASH_SIZE;
6881 enum enum_USE_LSB_TAG enum_USE_LSB_TAG;
6882 enum FLOAT_TO_STRING_BUFSIZE FLOAT_TO_STRING_BUFSIZE;
6883 enum Lisp_Bits Lisp_Bits;
6884 enum Lisp_Compiled Lisp_Compiled;
6885 enum maxargs maxargs;
6886 enum MAX_ALLOCA MAX_ALLOCA;
6887 enum More_Lisp_Bits More_Lisp_Bits;
6888 enum pvec_type pvec_type;
6889 #if USE_LSB_TAG
6890 enum lsb_bits lsb_bits;
6891 #endif
6892 } const EXTERNALLY_VISIBLE gdb_make_enums_visible = {0};