2 * GENerational Conservative Garbage Collector for SBCL
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
17 * For a review of garbage collection techniques (e.g. generational
18 * GC) and terminology (e.g. "scavenging") see Paul R. Wilson,
19 * "Uniprocessor Garbage Collection Techniques". As of 20000618, this
20 * had been accepted for _ACM Computing Surveys_ and was available
21 * as a PostScript preprint through
22 * <http://www.cs.utexas.edu/users/oops/papers.html>
24 * <ftp://ftp.cs.utexas.edu/pub/garbage/bigsurv.ps>.
37 #include "interrupt.h"
43 #include "gc-internal.h"
45 #include "genesis/vector.h"
46 #include "genesis/weak-pointer.h"
47 #include "genesis/fdefn.h"
48 #include "genesis/simple-fun.h"
50 #include "genesis/hash-table.h"
51 #include "genesis/instance.h"
52 #include "genesis/layout.h"
54 #if defined(LUTEX_WIDETAG)
55 #include "pthread-lutex.h"
58 /* forward declarations */
59 page_index_t
gc_find_freeish_pages(long *restart_page_ptr
, long nbytes
,
67 /* Generations 0-5 are normal collected generations, 6 is only used as
68 * scratch space by the collector, and should never get collected.
71 HIGHEST_NORMAL_GENERATION
= 5,
72 PSEUDO_STATIC_GENERATION
,
77 /* Should we use page protection to help avoid the scavenging of pages
78 * that don't have pointers to younger generations? */
79 boolean enable_page_protection
= 1;
81 /* the minimum size (in bytes) for a large object*/
82 unsigned long large_object_size
= 4 * PAGE_BYTES
;
89 /* the verbosity level. All non-error messages are disabled at level 0;
90 * and only a few rare messages are printed at level 1. */
92 boolean gencgc_verbose
= 1;
94 boolean gencgc_verbose
= 0;
97 /* FIXME: At some point enable the various error-checking things below
98 * and see what they say. */
100 /* We hunt for pointers to old-space, when GCing generations >= verify_gen.
101 * Set verify_gens to HIGHEST_NORMAL_GENERATION + 1 to disable this kind of
103 generation_index_t verify_gens
= HIGHEST_NORMAL_GENERATION
+ 1;
105 /* Should we do a pre-scan verify of generation 0 before it's GCed? */
106 boolean pre_verify_gen_0
= 0;
108 /* Should we check for bad pointers after gc_free_heap is called
109 * from Lisp PURIFY? */
110 boolean verify_after_free_heap
= 0;
112 /* Should we print a note when code objects are found in the dynamic space
113 * during a heap verify? */
114 boolean verify_dynamic_code_check
= 0;
116 /* Should we check code objects for fixup errors after they are transported? */
117 boolean check_code_fixups
= 0;
119 /* Should we check that newly allocated regions are zero filled? */
120 boolean gencgc_zero_check
= 0;
122 /* Should we check that the free space is zero filled? */
123 boolean gencgc_enable_verify_zero_fill
= 0;
125 /* Should we check that free pages are zero filled during gc_free_heap
126 * called after Lisp PURIFY? */
127 boolean gencgc_zero_check_during_free_heap
= 0;
129 /* When loading a core, don't do a full scan of the memory for the
130 * memory region boundaries. (Set to true by coreparse.c if the core
131 * contained a pagetable entry).
133 boolean gencgc_partial_pickup
= 0;
135 /* If defined, free pages are read-protected to ensure that nothing
139 /* #define READ_PROTECT_FREE_PAGES */
143 * GC structures and variables
146 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
147 unsigned long bytes_allocated
= 0;
148 unsigned long auto_gc_trigger
= 0;
150 /* the source and destination generations. These are set before a GC starts
152 generation_index_t from_space
;
153 generation_index_t new_space
;
155 /* Set to 1 when in GC */
156 boolean gc_active_p
= 0;
158 /* should the GC be conservative on stack. If false (only right before
159 * saving a core), don't scan the stack / mark pages dont_move. */
160 static boolean conservative_stack
= 1;
162 /* An array of page structures is allocated on gc initialization.
163 * This helps quickly map between an address its page structure.
164 * page_table_pages is set from the size of the dynamic space. */
165 unsigned page_table_pages
;
166 struct page
*page_table
;
168 /* To map addresses to page structures the address of the first page
170 static void *heap_base
= NULL
;
172 /* Calculate the start address for the given page number. */
174 page_address(page_index_t page_num
)
176 return (heap_base
+ (page_num
* PAGE_BYTES
));
179 /* Find the page index within the page_table for the given
180 * address. Return -1 on failure. */
182 find_page_index(void *addr
)
184 page_index_t index
= addr
-heap_base
;
187 index
= ((unsigned long)index
)/PAGE_BYTES
;
188 if (index
< page_table_pages
)
195 /* a structure to hold the state of a generation */
198 /* the first page that gc_alloc() checks on its next call */
199 page_index_t alloc_start_page
;
201 /* the first page that gc_alloc_unboxed() checks on its next call */
202 page_index_t alloc_unboxed_start_page
;
204 /* the first page that gc_alloc_large (boxed) considers on its next
205 * call. (Although it always allocates after the boxed_region.) */
206 page_index_t alloc_large_start_page
;
208 /* the first page that gc_alloc_large (unboxed) considers on its
209 * next call. (Although it always allocates after the
210 * current_unboxed_region.) */
211 page_index_t alloc_large_unboxed_start_page
;
213 /* the bytes allocated to this generation */
214 long bytes_allocated
;
216 /* the number of bytes at which to trigger a GC */
219 /* to calculate a new level for gc_trigger */
220 long bytes_consed_between_gc
;
222 /* the number of GCs since the last raise */
225 /* the average age after which a GC will raise objects to the
229 /* the cumulative sum of the bytes allocated to this generation. It is
230 * cleared after a GC on this generations, and update before new
231 * objects are added from a GC of a younger generation. Dividing by
232 * the bytes_allocated will give the average age of the memory in
233 * this generation since its last GC. */
234 long cum_sum_bytes_allocated
;
236 /* a minimum average memory age before a GC will occur helps
237 * prevent a GC when a large number of new live objects have been
238 * added, in which case a GC could be a waste of time */
239 double min_av_mem_age
;
241 /* A linked list of lutex structures in this generation, used for
242 * implementing lutex finalization. */
244 struct lutex
*lutexes
;
250 /* an array of generation structures. There needs to be one more
251 * generation structure than actual generations as the oldest
252 * generation is temporarily raised then lowered. */
253 struct generation generations
[NUM_GENERATIONS
];
255 /* the oldest generation that is will currently be GCed by default.
256 * Valid values are: 0, 1, ... HIGHEST_NORMAL_GENERATION
258 * The default of HIGHEST_NORMAL_GENERATION enables GC on all generations.
260 * Setting this to 0 effectively disables the generational nature of
261 * the GC. In some applications generational GC may not be useful
262 * because there are no long-lived objects.
264 * An intermediate value could be handy after moving long-lived data
265 * into an older generation so an unnecessary GC of this long-lived
266 * data can be avoided. */
267 generation_index_t gencgc_oldest_gen_to_gc
= HIGHEST_NORMAL_GENERATION
;
269 /* The maximum free page in the heap is maintained and used to update
270 * ALLOCATION_POINTER which is used by the room function to limit its
271 * search of the heap. XX Gencgc obviously needs to be better
272 * integrated with the Lisp code. */
273 page_index_t last_free_page
;
275 /* This lock is to prevent multiple threads from simultaneously
276 * allocating new regions which overlap each other. Note that the
277 * majority of GC is single-threaded, but alloc() may be called from
278 * >1 thread at a time and must be thread-safe. This lock must be
279 * seized before all accesses to generations[] or to parts of
280 * page_table[] that other threads may want to see */
282 #ifdef LISP_FEATURE_SB_THREAD
283 static pthread_mutex_t free_pages_lock
= PTHREAD_MUTEX_INITIALIZER
;
288 * miscellaneous heap functions
291 /* Count the number of pages which are write-protected within the
292 * given generation. */
294 count_write_protect_generation_pages(generation_index_t generation
)
299 for (i
= 0; i
< last_free_page
; i
++)
300 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
301 && (page_table
[i
].gen
== generation
)
302 && (page_table
[i
].write_protected
== 1))
307 /* Count the number of pages within the given generation. */
309 count_generation_pages(generation_index_t generation
)
314 for (i
= 0; i
< last_free_page
; i
++)
315 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
316 && (page_table
[i
].gen
== generation
))
323 count_dont_move_pages(void)
327 for (i
= 0; i
< last_free_page
; i
++) {
328 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
329 && (page_table
[i
].dont_move
!= 0)) {
337 /* Work through the pages and add up the number of bytes used for the
338 * given generation. */
340 count_generation_bytes_allocated (generation_index_t gen
)
344 for (i
= 0; i
< last_free_page
; i
++) {
345 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
346 && (page_table
[i
].gen
== gen
))
347 result
+= page_table
[i
].bytes_used
;
352 /* Return the average age of the memory in a generation. */
354 gen_av_mem_age(generation_index_t gen
)
356 if (generations
[gen
].bytes_allocated
== 0)
360 ((double)generations
[gen
].cum_sum_bytes_allocated
)
361 / ((double)generations
[gen
].bytes_allocated
);
364 /* The verbose argument controls how much to print: 0 for normal
365 * level of detail; 1 for debugging. */
367 print_generation_stats(int verbose
) /* FIXME: should take FILE argument */
369 generation_index_t i
, gens
;
371 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
372 #define FPU_STATE_SIZE 27
373 int fpu_state
[FPU_STATE_SIZE
];
374 #elif defined(LISP_FEATURE_PPC)
375 #define FPU_STATE_SIZE 32
376 long long fpu_state
[FPU_STATE_SIZE
];
379 /* This code uses the FP instructions which may be set up for Lisp
380 * so they need to be saved and reset for C. */
383 /* highest generation to print */
385 gens
= SCRATCH_GENERATION
;
387 gens
= PSEUDO_STATIC_GENERATION
;
389 /* Print the heap stats. */
391 " Gen StaPg UbSta LaSta LUbSt Boxed Unboxed LB LUB !move Alloc Waste Trig WP GCs Mem-age\n");
393 for (i
= 0; i
< gens
; i
++) {
396 long unboxed_cnt
= 0;
397 long large_boxed_cnt
= 0;
398 long large_unboxed_cnt
= 0;
401 for (j
= 0; j
< last_free_page
; j
++)
402 if (page_table
[j
].gen
== i
) {
404 /* Count the number of boxed pages within the given
406 if (page_table
[j
].allocated
& BOXED_PAGE_FLAG
) {
407 if (page_table
[j
].large_object
)
412 if(page_table
[j
].dont_move
) pinned_cnt
++;
413 /* Count the number of unboxed pages within the given
415 if (page_table
[j
].allocated
& UNBOXED_PAGE_FLAG
) {
416 if (page_table
[j
].large_object
)
423 gc_assert(generations
[i
].bytes_allocated
424 == count_generation_bytes_allocated(i
));
426 " %1d: %5ld %5ld %5ld %5ld %5ld %5ld %5ld %5ld %5ld %8ld %5ld %8ld %4ld %3d %7.4f\n",
428 generations
[i
].alloc_start_page
,
429 generations
[i
].alloc_unboxed_start_page
,
430 generations
[i
].alloc_large_start_page
,
431 generations
[i
].alloc_large_unboxed_start_page
,
437 generations
[i
].bytes_allocated
,
438 (count_generation_pages(i
)*PAGE_BYTES
- generations
[i
].bytes_allocated
),
439 generations
[i
].gc_trigger
,
440 count_write_protect_generation_pages(i
),
441 generations
[i
].num_gc
,
444 fprintf(stderr
," Total bytes allocated=%ld\n", bytes_allocated
);
446 fpu_restore(fpu_state
);
450 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
451 void fast_bzero(void*, size_t); /* in <arch>-assem.S */
454 /* Zero the pages from START to END (inclusive), but use mmap/munmap instead
455 * if zeroing it ourselves, i.e. in practice give the memory back to the
456 * OS. Generally done after a large GC.
458 void zero_pages_with_mmap(page_index_t start
, page_index_t end
) {
460 void *addr
= (void *) page_address(start
), *new_addr
;
461 size_t length
= PAGE_BYTES
*(1+end
-start
);
466 os_invalidate(addr
, length
);
467 new_addr
= os_validate(addr
, length
);
468 if (new_addr
== NULL
|| new_addr
!= addr
) {
469 lose("remap_free_pages: page moved, 0x%08x ==> 0x%08x", start
, new_addr
);
472 for (i
= start
; i
<= end
; i
++) {
473 page_table
[i
].need_to_zero
= 0;
477 /* Zero the pages from START to END (inclusive). Generally done just after
478 * a new region has been allocated.
481 zero_pages(page_index_t start
, page_index_t end
) {
485 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
486 fast_bzero(page_address(start
), PAGE_BYTES
*(1+end
-start
));
488 bzero(page_address(start
), PAGE_BYTES
*(1+end
-start
));
493 /* Zero the pages from START to END (inclusive), except for those
494 * pages that are known to already zeroed. Mark all pages in the
495 * ranges as non-zeroed.
498 zero_dirty_pages(page_index_t start
, page_index_t end
) {
501 for (i
= start
; i
<= end
; i
++) {
502 if (page_table
[i
].need_to_zero
== 1) {
503 zero_pages(start
, end
);
508 for (i
= start
; i
<= end
; i
++) {
509 page_table
[i
].need_to_zero
= 1;
515 * To support quick and inline allocation, regions of memory can be
516 * allocated and then allocated from with just a free pointer and a
517 * check against an end address.
519 * Since objects can be allocated to spaces with different properties
520 * e.g. boxed/unboxed, generation, ages; there may need to be many
521 * allocation regions.
523 * Each allocation region may start within a partly used page. Many
524 * features of memory use are noted on a page wise basis, e.g. the
525 * generation; so if a region starts within an existing allocated page
526 * it must be consistent with this page.
528 * During the scavenging of the newspace, objects will be transported
529 * into an allocation region, and pointers updated to point to this
530 * allocation region. It is possible that these pointers will be
531 * scavenged again before the allocation region is closed, e.g. due to
532 * trans_list which jumps all over the place to cleanup the list. It
533 * is important to be able to determine properties of all objects
534 * pointed to when scavenging, e.g to detect pointers to the oldspace.
535 * Thus it's important that the allocation regions have the correct
536 * properties set when allocated, and not just set when closed. The
537 * region allocation routines return regions with the specified
538 * properties, and grab all the pages, setting their properties
539 * appropriately, except that the amount used is not known.
541 * These regions are used to support quicker allocation using just a
542 * free pointer. The actual space used by the region is not reflected
543 * in the pages tables until it is closed. It can't be scavenged until
546 * When finished with the region it should be closed, which will
547 * update the page tables for the actual space used returning unused
548 * space. Further it may be noted in the new regions which is
549 * necessary when scavenging the newspace.
551 * Large objects may be allocated directly without an allocation
552 * region, the page tables are updated immediately.
554 * Unboxed objects don't contain pointers to other objects and so
555 * don't need scavenging. Further they can't contain pointers to
556 * younger generations so WP is not needed. By allocating pages to
557 * unboxed objects the whole page never needs scavenging or
558 * write-protecting. */
560 /* We are only using two regions at present. Both are for the current
561 * newspace generation. */
562 struct alloc_region boxed_region
;
563 struct alloc_region unboxed_region
;
565 /* The generation currently being allocated to. */
566 static generation_index_t gc_alloc_generation
;
568 /* Find a new region with room for at least the given number of bytes.
570 * It starts looking at the current generation's alloc_start_page. So
571 * may pick up from the previous region if there is enough space. This
572 * keeps the allocation contiguous when scavenging the newspace.
574 * The alloc_region should have been closed by a call to
575 * gc_alloc_update_page_tables(), and will thus be in an empty state.
577 * To assist the scavenging functions write-protected pages are not
578 * used. Free pages should not be write-protected.
580 * It is critical to the conservative GC that the start of regions be
581 * known. To help achieve this only small regions are allocated at a
584 * During scavenging, pointers may be found to within the current
585 * region and the page generation must be set so that pointers to the
586 * from space can be recognized. Therefore the generation of pages in
587 * the region are set to gc_alloc_generation. To prevent another
588 * allocation call using the same pages, all the pages in the region
589 * are allocated, although they will initially be empty.
592 gc_alloc_new_region(long nbytes
, int unboxed
, struct alloc_region
*alloc_region
)
594 page_index_t first_page
;
595 page_index_t last_page
;
602 "/alloc_new_region for %d bytes from gen %d\n",
603 nbytes, gc_alloc_generation));
606 /* Check that the region is in a reset state. */
607 gc_assert((alloc_region
->first_page
== 0)
608 && (alloc_region
->last_page
== -1)
609 && (alloc_region
->free_pointer
== alloc_region
->end_addr
));
610 ret
= thread_mutex_lock(&free_pages_lock
);
614 generations
[gc_alloc_generation
].alloc_unboxed_start_page
;
617 generations
[gc_alloc_generation
].alloc_start_page
;
619 last_page
=gc_find_freeish_pages(&first_page
,nbytes
,unboxed
);
620 bytes_found
=(PAGE_BYTES
- page_table
[first_page
].bytes_used
)
621 + PAGE_BYTES
*(last_page
-first_page
);
623 /* Set up the alloc_region. */
624 alloc_region
->first_page
= first_page
;
625 alloc_region
->last_page
= last_page
;
626 alloc_region
->start_addr
= page_table
[first_page
].bytes_used
627 + page_address(first_page
);
628 alloc_region
->free_pointer
= alloc_region
->start_addr
;
629 alloc_region
->end_addr
= alloc_region
->start_addr
+ bytes_found
;
631 /* Set up the pages. */
633 /* The first page may have already been in use. */
634 if (page_table
[first_page
].bytes_used
== 0) {
636 page_table
[first_page
].allocated
= UNBOXED_PAGE_FLAG
;
638 page_table
[first_page
].allocated
= BOXED_PAGE_FLAG
;
639 page_table
[first_page
].gen
= gc_alloc_generation
;
640 page_table
[first_page
].large_object
= 0;
641 page_table
[first_page
].first_object_offset
= 0;
645 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
647 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
648 page_table
[first_page
].allocated
|= OPEN_REGION_PAGE_FLAG
;
650 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
651 gc_assert(page_table
[first_page
].large_object
== 0);
653 for (i
= first_page
+1; i
<= last_page
; i
++) {
655 page_table
[i
].allocated
= UNBOXED_PAGE_FLAG
;
657 page_table
[i
].allocated
= BOXED_PAGE_FLAG
;
658 page_table
[i
].gen
= gc_alloc_generation
;
659 page_table
[i
].large_object
= 0;
660 /* This may not be necessary for unboxed regions (think it was
662 page_table
[i
].first_object_offset
=
663 alloc_region
->start_addr
- page_address(i
);
664 page_table
[i
].allocated
|= OPEN_REGION_PAGE_FLAG
;
666 /* Bump up last_free_page. */
667 if (last_page
+1 > last_free_page
) {
668 last_free_page
= last_page
+1;
669 /* do we only want to call this on special occasions? like for boxed_region? */
670 set_alloc_pointer((lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
));
672 ret
= thread_mutex_unlock(&free_pages_lock
);
675 /* we can do this after releasing free_pages_lock */
676 if (gencgc_zero_check
) {
678 for (p
= (long *)alloc_region
->start_addr
;
679 p
< (long *)alloc_region
->end_addr
; p
++) {
681 /* KLUDGE: It would be nice to use %lx and explicit casts
682 * (long) in code like this, so that it is less likely to
683 * break randomly when running on a machine with different
684 * word sizes. -- WHN 19991129 */
685 lose("The new region at %x is not zero.\n", p
);
690 #ifdef READ_PROTECT_FREE_PAGES
691 os_protect(page_address(first_page
),
692 PAGE_BYTES
*(1+last_page
-first_page
),
696 /* If the first page was only partial, don't check whether it's
697 * zeroed (it won't be) and don't zero it (since the parts that
698 * we're interested in are guaranteed to be zeroed).
700 if (page_table
[first_page
].bytes_used
) {
704 zero_dirty_pages(first_page
, last_page
);
707 /* If the record_new_objects flag is 2 then all new regions created
710 * If it's 1 then then it is only recorded if the first page of the
711 * current region is <= new_areas_ignore_page. This helps avoid
712 * unnecessary recording when doing full scavenge pass.
714 * The new_object structure holds the page, byte offset, and size of
715 * new regions of objects. Each new area is placed in the array of
716 * these structures pointer to by new_areas. new_areas_index holds the
717 * offset into new_areas.
719 * If new_area overflows NUM_NEW_AREAS then it stops adding them. The
720 * later code must detect this and handle it, probably by doing a full
721 * scavenge of a generation. */
722 #define NUM_NEW_AREAS 512
723 static int record_new_objects
= 0;
724 static page_index_t new_areas_ignore_page
;
730 static struct new_area (*new_areas
)[];
731 static long new_areas_index
;
734 /* Add a new area to new_areas. */
736 add_new_area(page_index_t first_page
, long offset
, long size
)
738 unsigned long new_area_start
,c
;
741 /* Ignore if full. */
742 if (new_areas_index
>= NUM_NEW_AREAS
)
745 switch (record_new_objects
) {
749 if (first_page
> new_areas_ignore_page
)
758 new_area_start
= PAGE_BYTES
*first_page
+ offset
;
760 /* Search backwards for a prior area that this follows from. If
761 found this will save adding a new area. */
762 for (i
= new_areas_index
-1, c
= 0; (i
>= 0) && (c
< 8); i
--, c
++) {
763 unsigned long area_end
=
764 PAGE_BYTES
*((*new_areas
)[i
].page
)
765 + (*new_areas
)[i
].offset
766 + (*new_areas
)[i
].size
;
768 "/add_new_area S1 %d %d %d %d\n",
769 i, c, new_area_start, area_end));*/
770 if (new_area_start
== area_end
) {
772 "/adding to [%d] %d %d %d with %d %d %d:\n",
774 (*new_areas)[i].page,
775 (*new_areas)[i].offset,
776 (*new_areas)[i].size,
780 (*new_areas
)[i
].size
+= size
;
785 (*new_areas
)[new_areas_index
].page
= first_page
;
786 (*new_areas
)[new_areas_index
].offset
= offset
;
787 (*new_areas
)[new_areas_index
].size
= size
;
789 "/new_area %d page %d offset %d size %d\n",
790 new_areas_index, first_page, offset, size));*/
793 /* Note the max new_areas used. */
794 if (new_areas_index
> max_new_areas
)
795 max_new_areas
= new_areas_index
;
798 /* Update the tables for the alloc_region. The region may be added to
801 * When done the alloc_region is set up so that the next quick alloc
802 * will fail safely and thus a new region will be allocated. Further
803 * it is safe to try to re-update the page table of this reset
806 gc_alloc_update_page_tables(int unboxed
, struct alloc_region
*alloc_region
)
809 page_index_t first_page
;
810 page_index_t next_page
;
812 long orig_first_page_bytes_used
;
818 first_page
= alloc_region
->first_page
;
820 /* Catch an unused alloc_region. */
821 if ((first_page
== 0) && (alloc_region
->last_page
== -1))
824 next_page
= first_page
+1;
826 ret
= thread_mutex_lock(&free_pages_lock
);
828 if (alloc_region
->free_pointer
!= alloc_region
->start_addr
) {
829 /* some bytes were allocated in the region */
830 orig_first_page_bytes_used
= page_table
[first_page
].bytes_used
;
832 gc_assert(alloc_region
->start_addr
== (page_address(first_page
) + page_table
[first_page
].bytes_used
));
834 /* All the pages used need to be updated */
836 /* Update the first page. */
838 /* If the page was free then set up the gen, and
839 * first_object_offset. */
840 if (page_table
[first_page
].bytes_used
== 0)
841 gc_assert(page_table
[first_page
].first_object_offset
== 0);
842 page_table
[first_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
845 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
847 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
848 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
849 gc_assert(page_table
[first_page
].large_object
== 0);
853 /* Calculate the number of bytes used in this page. This is not
854 * always the number of new bytes, unless it was free. */
856 if ((bytes_used
= (alloc_region
->free_pointer
- page_address(first_page
)))>PAGE_BYTES
) {
857 bytes_used
= PAGE_BYTES
;
860 page_table
[first_page
].bytes_used
= bytes_used
;
861 byte_cnt
+= bytes_used
;
864 /* All the rest of the pages should be free. We need to set their
865 * first_object_offset pointer to the start of the region, and set
868 page_table
[next_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
870 gc_assert(page_table
[next_page
].allocated
==UNBOXED_PAGE_FLAG
);
872 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
873 gc_assert(page_table
[next_page
].bytes_used
== 0);
874 gc_assert(page_table
[next_page
].gen
== gc_alloc_generation
);
875 gc_assert(page_table
[next_page
].large_object
== 0);
877 gc_assert(page_table
[next_page
].first_object_offset
==
878 alloc_region
->start_addr
- page_address(next_page
));
880 /* Calculate the number of bytes used in this page. */
882 if ((bytes_used
= (alloc_region
->free_pointer
883 - page_address(next_page
)))>PAGE_BYTES
) {
884 bytes_used
= PAGE_BYTES
;
887 page_table
[next_page
].bytes_used
= bytes_used
;
888 byte_cnt
+= bytes_used
;
893 region_size
= alloc_region
->free_pointer
- alloc_region
->start_addr
;
894 bytes_allocated
+= region_size
;
895 generations
[gc_alloc_generation
].bytes_allocated
+= region_size
;
897 gc_assert((byte_cnt
- orig_first_page_bytes_used
) == region_size
);
899 /* Set the generations alloc restart page to the last page of
902 generations
[gc_alloc_generation
].alloc_unboxed_start_page
=
905 generations
[gc_alloc_generation
].alloc_start_page
= next_page
-1;
907 /* Add the region to the new_areas if requested. */
909 add_new_area(first_page
,orig_first_page_bytes_used
, region_size
);
913 "/gc_alloc_update_page_tables update %d bytes to gen %d\n",
915 gc_alloc_generation));
918 /* There are no bytes allocated. Unallocate the first_page if
919 * there are 0 bytes_used. */
920 page_table
[first_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
921 if (page_table
[first_page
].bytes_used
== 0)
922 page_table
[first_page
].allocated
= FREE_PAGE_FLAG
;
925 /* Unallocate any unused pages. */
926 while (next_page
<= alloc_region
->last_page
) {
927 gc_assert(page_table
[next_page
].bytes_used
== 0);
928 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
931 ret
= thread_mutex_unlock(&free_pages_lock
);
934 /* alloc_region is per-thread, we're ok to do this unlocked */
935 gc_set_region_empty(alloc_region
);
938 static inline void *gc_quick_alloc(long nbytes
);
940 /* Allocate a possibly large object. */
942 gc_alloc_large(long nbytes
, int unboxed
, struct alloc_region
*alloc_region
)
944 page_index_t first_page
;
945 page_index_t last_page
;
946 int orig_first_page_bytes_used
;
950 page_index_t next_page
;
953 ret
= thread_mutex_lock(&free_pages_lock
);
958 generations
[gc_alloc_generation
].alloc_large_unboxed_start_page
;
960 first_page
= generations
[gc_alloc_generation
].alloc_large_start_page
;
962 if (first_page
<= alloc_region
->last_page
) {
963 first_page
= alloc_region
->last_page
+1;
966 last_page
=gc_find_freeish_pages(&first_page
,nbytes
,unboxed
);
968 gc_assert(first_page
> alloc_region
->last_page
);
970 generations
[gc_alloc_generation
].alloc_large_unboxed_start_page
=
973 generations
[gc_alloc_generation
].alloc_large_start_page
= last_page
;
975 /* Set up the pages. */
976 orig_first_page_bytes_used
= page_table
[first_page
].bytes_used
;
978 /* If the first page was free then set up the gen, and
979 * first_object_offset. */
980 if (page_table
[first_page
].bytes_used
== 0) {
982 page_table
[first_page
].allocated
= UNBOXED_PAGE_FLAG
;
984 page_table
[first_page
].allocated
= BOXED_PAGE_FLAG
;
985 page_table
[first_page
].gen
= gc_alloc_generation
;
986 page_table
[first_page
].first_object_offset
= 0;
987 page_table
[first_page
].large_object
= 1;
991 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
993 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
994 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
995 gc_assert(page_table
[first_page
].large_object
== 1);
999 /* Calc. the number of bytes used in this page. This is not
1000 * always the number of new bytes, unless it was free. */
1002 if ((bytes_used
= nbytes
+orig_first_page_bytes_used
) > PAGE_BYTES
) {
1003 bytes_used
= PAGE_BYTES
;
1006 page_table
[first_page
].bytes_used
= bytes_used
;
1007 byte_cnt
+= bytes_used
;
1009 next_page
= first_page
+1;
1011 /* All the rest of the pages should be free. We need to set their
1012 * first_object_offset pointer to the start of the region, and
1013 * set the bytes_used. */
1015 gc_assert(page_table
[next_page
].allocated
== FREE_PAGE_FLAG
);
1016 gc_assert(page_table
[next_page
].bytes_used
== 0);
1018 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
1020 page_table
[next_page
].allocated
= BOXED_PAGE_FLAG
;
1021 page_table
[next_page
].gen
= gc_alloc_generation
;
1022 page_table
[next_page
].large_object
= 1;
1024 page_table
[next_page
].first_object_offset
=
1025 orig_first_page_bytes_used
- PAGE_BYTES
*(next_page
-first_page
);
1027 /* Calculate the number of bytes used in this page. */
1029 if ((bytes_used
=(nbytes
+orig_first_page_bytes_used
)-byte_cnt
) > PAGE_BYTES
) {
1030 bytes_used
= PAGE_BYTES
;
1033 page_table
[next_page
].bytes_used
= bytes_used
;
1034 page_table
[next_page
].write_protected
=0;
1035 page_table
[next_page
].dont_move
=0;
1036 byte_cnt
+= bytes_used
;
1040 gc_assert((byte_cnt
-orig_first_page_bytes_used
) == nbytes
);
1042 bytes_allocated
+= nbytes
;
1043 generations
[gc_alloc_generation
].bytes_allocated
+= nbytes
;
1045 /* Add the region to the new_areas if requested. */
1047 add_new_area(first_page
,orig_first_page_bytes_used
,nbytes
);
1049 /* Bump up last_free_page */
1050 if (last_page
+1 > last_free_page
) {
1051 last_free_page
= last_page
+1;
1052 set_alloc_pointer((lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
));
1054 ret
= thread_mutex_unlock(&free_pages_lock
);
1055 gc_assert(ret
== 0);
1057 #ifdef READ_PROTECT_FREE_PAGES
1058 os_protect(page_address(first_page
),
1059 PAGE_BYTES
*(1+last_page
-first_page
),
1063 zero_dirty_pages(first_page
, last_page
);
1065 return page_address(first_page
);
1068 static page_index_t gencgc_alloc_start_page
= -1;
1071 gc_heap_exhausted_error_or_lose (long available
, long requested
)
1073 /* Write basic information before doing anything else: if we don't
1074 * call to lisp this is a must, and even if we do there is always
1075 * the danger that we bounce back here before the error has been
1076 * handled, or indeed even printed.
1078 fprintf(stderr
, "Heap exhausted during %s: %ld bytes available, %ld requested.\n",
1079 gc_active_p
? "garbage collection" : "allocation", available
, requested
);
1080 if (gc_active_p
|| (available
== 0)) {
1081 /* If we are in GC, or totally out of memory there is no way
1082 * to sanely transfer control to the lisp-side of things.
1084 struct thread
*thread
= arch_os_get_current_thread();
1085 print_generation_stats(1);
1086 fprintf(stderr
, "GC control variables:\n");
1087 fprintf(stderr
, " *GC-INHIBIT* = %s\n *GC-PENDING* = %s\n",
1088 SymbolValue(GC_INHIBIT
,thread
)==NIL
? "false" : "true",
1089 SymbolValue(GC_PENDING
,thread
)==NIL
? "false" : "true");
1090 #ifdef LISP_FEATURE_SB_THREAD
1091 fprintf(stderr
, " *STOP-FOR-GC-PENDING* = %s\n",
1092 SymbolValue(STOP_FOR_GC_PENDING
,thread
)==NIL
? "false" : "true");
1094 lose("Heap exhausted, game over.");
1097 /* FIXME: assert free_pages_lock held */
1098 thread_mutex_unlock(&free_pages_lock
);
1099 funcall2(SymbolFunction(HEAP_EXHAUSTED_ERROR
),
1100 alloc_number(available
), alloc_number(requested
));
1101 lose("HEAP-EXHAUSTED-ERROR fell through");
1106 gc_find_freeish_pages(page_index_t
*restart_page_ptr
, long nbytes
, int unboxed
)
1108 page_index_t first_page
;
1109 page_index_t last_page
;
1111 page_index_t restart_page
=*restart_page_ptr
;
1114 int large_p
=(nbytes
>=large_object_size
);
1115 /* FIXME: assert(free_pages_lock is held); */
1117 /* Search for a contiguous free space of at least nbytes. If it's
1118 * a large object then align it on a page boundary by searching
1119 * for a free page. */
1121 if (gencgc_alloc_start_page
!= -1) {
1122 restart_page
= gencgc_alloc_start_page
;
1126 first_page
= restart_page
;
1128 while ((first_page
< page_table_pages
)
1129 && (page_table
[first_page
].allocated
!= FREE_PAGE_FLAG
))
1132 while (first_page
< page_table_pages
) {
1133 if(page_table
[first_page
].allocated
== FREE_PAGE_FLAG
)
1135 if((page_table
[first_page
].allocated
==
1136 (unboxed
? UNBOXED_PAGE_FLAG
: BOXED_PAGE_FLAG
)) &&
1137 (page_table
[first_page
].large_object
== 0) &&
1138 (page_table
[first_page
].gen
== gc_alloc_generation
) &&
1139 (page_table
[first_page
].bytes_used
< (PAGE_BYTES
-32)) &&
1140 (page_table
[first_page
].write_protected
== 0) &&
1141 (page_table
[first_page
].dont_move
== 0)) {
1147 if (first_page
>= page_table_pages
)
1148 gc_heap_exhausted_error_or_lose(0, nbytes
);
1150 gc_assert(page_table
[first_page
].write_protected
== 0);
1152 last_page
= first_page
;
1153 bytes_found
= PAGE_BYTES
- page_table
[first_page
].bytes_used
;
1155 while (((bytes_found
< nbytes
)
1156 || (!large_p
&& (num_pages
< 2)))
1157 && (last_page
< (page_table_pages
-1))
1158 && (page_table
[last_page
+1].allocated
== FREE_PAGE_FLAG
)) {
1161 bytes_found
+= PAGE_BYTES
;
1162 gc_assert(page_table
[last_page
].write_protected
== 0);
1165 region_size
= (PAGE_BYTES
- page_table
[first_page
].bytes_used
)
1166 + PAGE_BYTES
*(last_page
-first_page
);
1168 gc_assert(bytes_found
== region_size
);
1169 restart_page
= last_page
+ 1;
1170 } while ((restart_page
< page_table_pages
) && (bytes_found
< nbytes
));
1172 /* Check for a failure */
1173 if ((restart_page
>= page_table_pages
) && (bytes_found
< nbytes
))
1174 gc_heap_exhausted_error_or_lose(bytes_found
, nbytes
);
1176 *restart_page_ptr
=first_page
;
1181 /* Allocate bytes. All the rest of the special-purpose allocation
1182 * functions will eventually call this */
1185 gc_alloc_with_region(long nbytes
,int unboxed_p
, struct alloc_region
*my_region
,
1188 void *new_free_pointer
;
1190 if(nbytes
>=large_object_size
)
1191 return gc_alloc_large(nbytes
,unboxed_p
,my_region
);
1193 /* Check whether there is room in the current alloc region. */
1194 new_free_pointer
= my_region
->free_pointer
+ nbytes
;
1196 /* fprintf(stderr, "alloc %d bytes from %p to %p\n", nbytes,
1197 my_region->free_pointer, new_free_pointer); */
1199 if (new_free_pointer
<= my_region
->end_addr
) {
1200 /* If so then allocate from the current alloc region. */
1201 void *new_obj
= my_region
->free_pointer
;
1202 my_region
->free_pointer
= new_free_pointer
;
1204 /* Unless a `quick' alloc was requested, check whether the
1205 alloc region is almost empty. */
1207 (my_region
->end_addr
- my_region
->free_pointer
) <= 32) {
1208 /* If so, finished with the current region. */
1209 gc_alloc_update_page_tables(unboxed_p
, my_region
);
1210 /* Set up a new region. */
1211 gc_alloc_new_region(32 /*bytes*/, unboxed_p
, my_region
);
1214 return((void *)new_obj
);
1217 /* Else not enough free space in the current region: retry with a
1220 gc_alloc_update_page_tables(unboxed_p
, my_region
);
1221 gc_alloc_new_region(nbytes
, unboxed_p
, my_region
);
1222 return gc_alloc_with_region(nbytes
,unboxed_p
,my_region
,0);
1225 /* these are only used during GC: all allocation from the mutator calls
1226 * alloc() -> gc_alloc_with_region() with the appropriate per-thread
1230 gc_general_alloc(long nbytes
,int unboxed_p
,int quick_p
)
1232 struct alloc_region
*my_region
=
1233 unboxed_p
? &unboxed_region
: &boxed_region
;
1234 return gc_alloc_with_region(nbytes
,unboxed_p
, my_region
,quick_p
);
1237 static inline void *
1238 gc_quick_alloc(long nbytes
)
1240 return gc_general_alloc(nbytes
,ALLOC_BOXED
,ALLOC_QUICK
);
1243 static inline void *
1244 gc_quick_alloc_large(long nbytes
)
1246 return gc_general_alloc(nbytes
,ALLOC_BOXED
,ALLOC_QUICK
);
1249 static inline void *
1250 gc_alloc_unboxed(long nbytes
)
1252 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,0);
1255 static inline void *
1256 gc_quick_alloc_unboxed(long nbytes
)
1258 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,ALLOC_QUICK
);
1261 static inline void *
1262 gc_quick_alloc_large_unboxed(long nbytes
)
1264 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,ALLOC_QUICK
);
1268 * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
1271 extern long (*scavtab
[256])(lispobj
*where
, lispobj object
);
1272 extern lispobj (*transother
[256])(lispobj object
);
1273 extern long (*sizetab
[256])(lispobj
*where
);
1275 /* Copy a large boxed object. If the object is in a large object
1276 * region then it is simply promoted, else it is copied. If it's large
1277 * enough then it's copied to a large object region.
1279 * Vectors may have shrunk. If the object is not copied the space
1280 * needs to be reclaimed, and the page_tables corrected. */
1282 copy_large_object(lispobj object
, long nwords
)
1286 page_index_t first_page
;
1288 gc_assert(is_lisp_pointer(object
));
1289 gc_assert(from_space_p(object
));
1290 gc_assert((nwords
& 0x01) == 0);
1293 /* Check whether it's in a large object region. */
1294 first_page
= find_page_index((void *)object
);
1295 gc_assert(first_page
>= 0);
1297 if (page_table
[first_page
].large_object
) {
1299 /* Promote the object. */
1301 long remaining_bytes
;
1302 page_index_t next_page
;
1304 long old_bytes_used
;
1306 /* Note: Any page write-protection must be removed, else a
1307 * later scavenge_newspace may incorrectly not scavenge these
1308 * pages. This would not be necessary if they are added to the
1309 * new areas, but let's do it for them all (they'll probably
1310 * be written anyway?). */
1312 gc_assert(page_table
[first_page
].first_object_offset
== 0);
1314 next_page
= first_page
;
1315 remaining_bytes
= nwords
*N_WORD_BYTES
;
1316 while (remaining_bytes
> PAGE_BYTES
) {
1317 gc_assert(page_table
[next_page
].gen
== from_space
);
1318 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
1319 gc_assert(page_table
[next_page
].large_object
);
1320 gc_assert(page_table
[next_page
].first_object_offset
==
1321 -PAGE_BYTES
*(next_page
-first_page
));
1322 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
1324 page_table
[next_page
].gen
= new_space
;
1326 /* Remove any write-protection. We should be able to rely
1327 * on the write-protect flag to avoid redundant calls. */
1328 if (page_table
[next_page
].write_protected
) {
1329 os_protect(page_address(next_page
), PAGE_BYTES
, OS_VM_PROT_ALL
);
1330 page_table
[next_page
].write_protected
= 0;
1332 remaining_bytes
-= PAGE_BYTES
;
1336 /* Now only one page remains, but the object may have shrunk
1337 * so there may be more unused pages which will be freed. */
1339 /* The object may have shrunk but shouldn't have grown. */
1340 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
1342 page_table
[next_page
].gen
= new_space
;
1343 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
1345 /* Adjust the bytes_used. */
1346 old_bytes_used
= page_table
[next_page
].bytes_used
;
1347 page_table
[next_page
].bytes_used
= remaining_bytes
;
1349 bytes_freed
= old_bytes_used
- remaining_bytes
;
1351 /* Free any remaining pages; needs care. */
1353 while ((old_bytes_used
== PAGE_BYTES
) &&
1354 (page_table
[next_page
].gen
== from_space
) &&
1355 (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
) &&
1356 page_table
[next_page
].large_object
&&
1357 (page_table
[next_page
].first_object_offset
==
1358 -(next_page
- first_page
)*PAGE_BYTES
)) {
1359 /* Checks out OK, free the page. Don't need to bother zeroing
1360 * pages as this should have been done before shrinking the
1361 * object. These pages shouldn't be write-protected as they
1362 * should be zero filled. */
1363 gc_assert(page_table
[next_page
].write_protected
== 0);
1365 old_bytes_used
= page_table
[next_page
].bytes_used
;
1366 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
1367 page_table
[next_page
].bytes_used
= 0;
1368 bytes_freed
+= old_bytes_used
;
1372 generations
[from_space
].bytes_allocated
-= N_WORD_BYTES
*nwords
+
1374 generations
[new_space
].bytes_allocated
+= N_WORD_BYTES
*nwords
;
1375 bytes_allocated
-= bytes_freed
;
1377 /* Add the region to the new_areas if requested. */
1378 add_new_area(first_page
,0,nwords
*N_WORD_BYTES
);
1382 /* Get tag of object. */
1383 tag
= lowtag_of(object
);
1385 /* Allocate space. */
1386 new = gc_quick_alloc_large(nwords
*N_WORD_BYTES
);
1388 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1390 /* Return Lisp pointer of new object. */
1391 return ((lispobj
) new) | tag
;
1395 /* to copy unboxed objects */
1397 copy_unboxed_object(lispobj object
, long nwords
)
1402 gc_assert(is_lisp_pointer(object
));
1403 gc_assert(from_space_p(object
));
1404 gc_assert((nwords
& 0x01) == 0);
1406 /* Get tag of object. */
1407 tag
= lowtag_of(object
);
1409 /* Allocate space. */
1410 new = gc_quick_alloc_unboxed(nwords
*N_WORD_BYTES
);
1412 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1414 /* Return Lisp pointer of new object. */
1415 return ((lispobj
) new) | tag
;
1418 /* to copy large unboxed objects
1420 * If the object is in a large object region then it is simply
1421 * promoted, else it is copied. If it's large enough then it's copied
1422 * to a large object region.
1424 * Bignums and vectors may have shrunk. If the object is not copied
1425 * the space needs to be reclaimed, and the page_tables corrected.
1427 * KLUDGE: There's a lot of cut-and-paste duplication between this
1428 * function and copy_large_object(..). -- WHN 20000619 */
1430 copy_large_unboxed_object(lispobj object
, long nwords
)
1434 page_index_t first_page
;
1436 gc_assert(is_lisp_pointer(object
));
1437 gc_assert(from_space_p(object
));
1438 gc_assert((nwords
& 0x01) == 0);
1440 if ((nwords
> 1024*1024) && gencgc_verbose
)
1441 FSHOW((stderr
, "/copy_large_unboxed_object: %d bytes\n", nwords
*N_WORD_BYTES
));
1443 /* Check whether it's a large object. */
1444 first_page
= find_page_index((void *)object
);
1445 gc_assert(first_page
>= 0);
1447 if (page_table
[first_page
].large_object
) {
1448 /* Promote the object. Note: Unboxed objects may have been
1449 * allocated to a BOXED region so it may be necessary to
1450 * change the region to UNBOXED. */
1451 long remaining_bytes
;
1452 page_index_t next_page
;
1454 long old_bytes_used
;
1456 gc_assert(page_table
[first_page
].first_object_offset
== 0);
1458 next_page
= first_page
;
1459 remaining_bytes
= nwords
*N_WORD_BYTES
;
1460 while (remaining_bytes
> PAGE_BYTES
) {
1461 gc_assert(page_table
[next_page
].gen
== from_space
);
1462 gc_assert((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
1463 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
));
1464 gc_assert(page_table
[next_page
].large_object
);
1465 gc_assert(page_table
[next_page
].first_object_offset
==
1466 -PAGE_BYTES
*(next_page
-first_page
));
1467 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
1469 page_table
[next_page
].gen
= new_space
;
1470 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
1471 remaining_bytes
-= PAGE_BYTES
;
1475 /* Now only one page remains, but the object may have shrunk so
1476 * there may be more unused pages which will be freed. */
1478 /* Object may have shrunk but shouldn't have grown - check. */
1479 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
1481 page_table
[next_page
].gen
= new_space
;
1482 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
1484 /* Adjust the bytes_used. */
1485 old_bytes_used
= page_table
[next_page
].bytes_used
;
1486 page_table
[next_page
].bytes_used
= remaining_bytes
;
1488 bytes_freed
= old_bytes_used
- remaining_bytes
;
1490 /* Free any remaining pages; needs care. */
1492 while ((old_bytes_used
== PAGE_BYTES
) &&
1493 (page_table
[next_page
].gen
== from_space
) &&
1494 ((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
1495 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)) &&
1496 page_table
[next_page
].large_object
&&
1497 (page_table
[next_page
].first_object_offset
==
1498 -(next_page
- first_page
)*PAGE_BYTES
)) {
1499 /* Checks out OK, free the page. Don't need to both zeroing
1500 * pages as this should have been done before shrinking the
1501 * object. These pages shouldn't be write-protected, even if
1502 * boxed they should be zero filled. */
1503 gc_assert(page_table
[next_page
].write_protected
== 0);
1505 old_bytes_used
= page_table
[next_page
].bytes_used
;
1506 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
1507 page_table
[next_page
].bytes_used
= 0;
1508 bytes_freed
+= old_bytes_used
;
1512 if ((bytes_freed
> 0) && gencgc_verbose
)
1514 "/copy_large_unboxed bytes_freed=%d\n",
1517 generations
[from_space
].bytes_allocated
-= nwords
*N_WORD_BYTES
+ bytes_freed
;
1518 generations
[new_space
].bytes_allocated
+= nwords
*N_WORD_BYTES
;
1519 bytes_allocated
-= bytes_freed
;
1524 /* Get tag of object. */
1525 tag
= lowtag_of(object
);
1527 /* Allocate space. */
1528 new = gc_quick_alloc_large_unboxed(nwords
*N_WORD_BYTES
);
1530 /* Copy the object. */
1531 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1533 /* Return Lisp pointer of new object. */
1534 return ((lispobj
) new) | tag
;
1543 * code and code-related objects
1546 static lispobj trans_fun_header(lispobj object);
1547 static lispobj trans_boxed(lispobj object);
1550 /* Scan a x86 compiled code object, looking for possible fixups that
1551 * have been missed after a move.
1553 * Two types of fixups are needed:
1554 * 1. Absolute fixups to within the code object.
1555 * 2. Relative fixups to outside the code object.
1557 * Currently only absolute fixups to the constant vector, or to the
1558 * code area are checked. */
1560 sniff_code_object(struct code
*code
, unsigned long displacement
)
1562 #ifdef LISP_FEATURE_X86
1563 long nheader_words
, ncode_words
, nwords
;
1565 void *constants_start_addr
= NULL
, *constants_end_addr
;
1566 void *code_start_addr
, *code_end_addr
;
1567 int fixup_found
= 0;
1569 if (!check_code_fixups
)
1572 ncode_words
= fixnum_value(code
->code_size
);
1573 nheader_words
= HeaderValue(*(lispobj
*)code
);
1574 nwords
= ncode_words
+ nheader_words
;
1576 constants_start_addr
= (void *)code
+ 5*N_WORD_BYTES
;
1577 constants_end_addr
= (void *)code
+ nheader_words
*N_WORD_BYTES
;
1578 code_start_addr
= (void *)code
+ nheader_words
*N_WORD_BYTES
;
1579 code_end_addr
= (void *)code
+ nwords
*N_WORD_BYTES
;
1581 /* Work through the unboxed code. */
1582 for (p
= code_start_addr
; p
< code_end_addr
; p
++) {
1583 void *data
= *(void **)p
;
1584 unsigned d1
= *((unsigned char *)p
- 1);
1585 unsigned d2
= *((unsigned char *)p
- 2);
1586 unsigned d3
= *((unsigned char *)p
- 3);
1587 unsigned d4
= *((unsigned char *)p
- 4);
1589 unsigned d5
= *((unsigned char *)p
- 5);
1590 unsigned d6
= *((unsigned char *)p
- 6);
1593 /* Check for code references. */
1594 /* Check for a 32 bit word that looks like an absolute
1595 reference to within the code adea of the code object. */
1596 if ((data
>= (code_start_addr
-displacement
))
1597 && (data
< (code_end_addr
-displacement
))) {
1598 /* function header */
1600 && (((unsigned)p
- 4 - 4*HeaderValue(*((unsigned *)p
-1))) == (unsigned)code
)) {
1601 /* Skip the function header */
1605 /* the case of PUSH imm32 */
1609 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1610 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1611 FSHOW((stderr
, "/PUSH $0x%.8x\n", data
));
1613 /* the case of MOV [reg-8],imm32 */
1615 && (d2
==0x40 || d2
==0x41 || d2
==0x42 || d2
==0x43
1616 || d2
==0x45 || d2
==0x46 || d2
==0x47)
1620 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1621 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1622 FSHOW((stderr
, "/MOV [reg-8],$0x%.8x\n", data
));
1624 /* the case of LEA reg,[disp32] */
1625 if ((d2
== 0x8d) && ((d1
& 0xc7) == 5)) {
1628 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1629 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1630 FSHOW((stderr
,"/LEA reg,[$0x%.8x]\n", data
));
1634 /* Check for constant references. */
1635 /* Check for a 32 bit word that looks like an absolute
1636 reference to within the constant vector. Constant references
1638 if ((data
>= (constants_start_addr
-displacement
))
1639 && (data
< (constants_end_addr
-displacement
))
1640 && (((unsigned)data
& 0x3) == 0)) {
1645 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1646 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1647 FSHOW((stderr
,"/MOV eax,0x%.8x\n", data
));
1650 /* the case of MOV m32,EAX */
1654 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1655 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1656 FSHOW((stderr
, "/MOV 0x%.8x,eax\n", data
));
1659 /* the case of CMP m32,imm32 */
1660 if ((d1
== 0x3d) && (d2
== 0x81)) {
1663 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1664 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1666 FSHOW((stderr
, "/CMP 0x%.8x,immed32\n", data
));
1669 /* Check for a mod=00, r/m=101 byte. */
1670 if ((d1
& 0xc7) == 5) {
1675 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1676 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1677 FSHOW((stderr
,"/CMP 0x%.8x,reg\n", data
));
1679 /* the case of CMP reg32,m32 */
1683 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1684 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1685 FSHOW((stderr
, "/CMP reg32,0x%.8x\n", data
));
1687 /* the case of MOV m32,reg32 */
1691 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1692 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1693 FSHOW((stderr
, "/MOV 0x%.8x,reg32\n", data
));
1695 /* the case of MOV reg32,m32 */
1699 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1700 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1701 FSHOW((stderr
, "/MOV reg32,0x%.8x\n", data
));
1703 /* the case of LEA reg32,m32 */
1707 "abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1708 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1709 FSHOW((stderr
, "/LEA reg32,0x%.8x\n", data
));
1715 /* If anything was found, print some information on the code
1719 "/compiled code object at %x: header words = %d, code words = %d\n",
1720 code
, nheader_words
, ncode_words
));
1722 "/const start = %x, end = %x\n",
1723 constants_start_addr
, constants_end_addr
));
1725 "/code start = %x, end = %x\n",
1726 code_start_addr
, code_end_addr
));
1732 gencgc_apply_code_fixups(struct code
*old_code
, struct code
*new_code
)
1734 /* x86-64 uses pc-relative addressing instead of this kludge */
1735 #ifndef LISP_FEATURE_X86_64
1736 long nheader_words
, ncode_words
, nwords
;
1737 void *constants_start_addr
, *constants_end_addr
;
1738 void *code_start_addr
, *code_end_addr
;
1739 lispobj fixups
= NIL
;
1740 unsigned long displacement
= (unsigned long)new_code
- (unsigned long)old_code
;
1741 struct vector
*fixups_vector
;
1743 ncode_words
= fixnum_value(new_code
->code_size
);
1744 nheader_words
= HeaderValue(*(lispobj
*)new_code
);
1745 nwords
= ncode_words
+ nheader_words
;
1747 "/compiled code object at %x: header words = %d, code words = %d\n",
1748 new_code, nheader_words, ncode_words)); */
1749 constants_start_addr
= (void *)new_code
+ 5*N_WORD_BYTES
;
1750 constants_end_addr
= (void *)new_code
+ nheader_words
*N_WORD_BYTES
;
1751 code_start_addr
= (void *)new_code
+ nheader_words
*N_WORD_BYTES
;
1752 code_end_addr
= (void *)new_code
+ nwords
*N_WORD_BYTES
;
1755 "/const start = %x, end = %x\n",
1756 constants_start_addr,constants_end_addr));
1758 "/code start = %x; end = %x\n",
1759 code_start_addr,code_end_addr));
1762 /* The first constant should be a pointer to the fixups for this
1763 code objects. Check. */
1764 fixups
= new_code
->constants
[0];
1766 /* It will be 0 or the unbound-marker if there are no fixups (as
1767 * will be the case if the code object has been purified, for
1768 * example) and will be an other pointer if it is valid. */
1769 if ((fixups
== 0) || (fixups
== UNBOUND_MARKER_WIDETAG
) ||
1770 !is_lisp_pointer(fixups
)) {
1771 /* Check for possible errors. */
1772 if (check_code_fixups
)
1773 sniff_code_object(new_code
, displacement
);
1778 fixups_vector
= (struct vector
*)native_pointer(fixups
);
1780 /* Could be pointing to a forwarding pointer. */
1781 /* FIXME is this always in from_space? if so, could replace this code with
1782 * forwarding_pointer_p/forwarding_pointer_value */
1783 if (is_lisp_pointer(fixups
) &&
1784 (find_page_index((void*)fixups_vector
) != -1) &&
1785 (fixups_vector
->header
== 0x01)) {
1786 /* If so, then follow it. */
1787 /*SHOW("following pointer to a forwarding pointer");*/
1788 fixups_vector
= (struct vector
*)native_pointer((lispobj
)fixups_vector
->length
);
1791 /*SHOW("got fixups");*/
1793 if (widetag_of(fixups_vector
->header
) == SIMPLE_ARRAY_WORD_WIDETAG
) {
1794 /* Got the fixups for the code block. Now work through the vector,
1795 and apply a fixup at each address. */
1796 long length
= fixnum_value(fixups_vector
->length
);
1798 for (i
= 0; i
< length
; i
++) {
1799 unsigned long offset
= fixups_vector
->data
[i
];
1800 /* Now check the current value of offset. */
1801 unsigned long old_value
=
1802 *(unsigned long *)((unsigned long)code_start_addr
+ offset
);
1804 /* If it's within the old_code object then it must be an
1805 * absolute fixup (relative ones are not saved) */
1806 if ((old_value
>= (unsigned long)old_code
)
1807 && (old_value
< ((unsigned long)old_code
+ nwords
*N_WORD_BYTES
)))
1808 /* So add the dispacement. */
1809 *(unsigned long *)((unsigned long)code_start_addr
+ offset
) =
1810 old_value
+ displacement
;
1812 /* It is outside the old code object so it must be a
1813 * relative fixup (absolute fixups are not saved). So
1814 * subtract the displacement. */
1815 *(unsigned long *)((unsigned long)code_start_addr
+ offset
) =
1816 old_value
- displacement
;
1819 fprintf(stderr
, "widetag of fixup vector is %d\n", widetag_of(fixups_vector
->header
));
1822 /* Check for possible errors. */
1823 if (check_code_fixups
) {
1824 sniff_code_object(new_code
,displacement
);
1831 trans_boxed_large(lispobj object
)
1834 unsigned long length
;
1836 gc_assert(is_lisp_pointer(object
));
1838 header
= *((lispobj
*) native_pointer(object
));
1839 length
= HeaderValue(header
) + 1;
1840 length
= CEILING(length
, 2);
1842 return copy_large_object(object
, length
);
1845 /* Doesn't seem to be used, delete it after the grace period. */
1848 trans_unboxed_large(lispobj object
)
1851 unsigned long length
;
1853 gc_assert(is_lisp_pointer(object
));
1855 header
= *((lispobj
*) native_pointer(object
));
1856 length
= HeaderValue(header
) + 1;
1857 length
= CEILING(length
, 2);
1859 return copy_large_unboxed_object(object
, length
);
1865 * Lutexes. Using the normal finalization machinery for finalizing
1866 * lutexes is tricky, since the finalization depends on working lutexes.
1867 * So we track the lutexes in the GC and finalize them manually.
1870 #if defined(LUTEX_WIDETAG)
1873 * Start tracking LUTEX in the GC, by adding it to the linked list of
1874 * lutexes in the nursery generation. The caller is responsible for
1875 * locking, and GCs must be inhibited until the registration is
1879 gencgc_register_lutex (struct lutex
*lutex
) {
1880 int index
= find_page_index(lutex
);
1881 generation_index_t gen
;
1884 /* This lutex is in static space, so we don't need to worry about
1890 gen
= page_table
[index
].gen
;
1892 gc_assert(gen
>= 0);
1893 gc_assert(gen
< NUM_GENERATIONS
);
1895 head
= generations
[gen
].lutexes
;
1902 generations
[gen
].lutexes
= lutex
;
1906 * Stop tracking LUTEX in the GC by removing it from the appropriate
1907 * linked lists. This will only be called during GC, so no locking is
1911 gencgc_unregister_lutex (struct lutex
*lutex
) {
1913 lutex
->prev
->next
= lutex
->next
;
1915 generations
[lutex
->gen
].lutexes
= lutex
->next
;
1919 lutex
->next
->prev
= lutex
->prev
;
1928 * Mark all lutexes in generation GEN as not live.
1931 unmark_lutexes (generation_index_t gen
) {
1932 struct lutex
*lutex
= generations
[gen
].lutexes
;
1936 lutex
= lutex
->next
;
1941 * Finalize all lutexes in generation GEN that have not been marked live.
1944 reap_lutexes (generation_index_t gen
) {
1945 struct lutex
*lutex
= generations
[gen
].lutexes
;
1948 struct lutex
*next
= lutex
->next
;
1950 lutex_destroy((tagged_lutex_t
) lutex
);
1951 gencgc_unregister_lutex(lutex
);
1958 * Mark LUTEX as live.
1961 mark_lutex (lispobj tagged_lutex
) {
1962 struct lutex
*lutex
= (struct lutex
*) native_pointer(tagged_lutex
);
1968 * Move all lutexes in generation FROM to generation TO.
1971 move_lutexes (generation_index_t from
, generation_index_t to
) {
1972 struct lutex
*tail
= generations
[from
].lutexes
;
1974 /* Nothing to move */
1978 /* Change the generation of the lutexes in FROM. */
1979 while (tail
->next
) {
1985 /* Link the last lutex in the FROM list to the start of the TO list */
1986 tail
->next
= generations
[to
].lutexes
;
1988 /* And vice versa */
1989 if (generations
[to
].lutexes
) {
1990 generations
[to
].lutexes
->prev
= tail
;
1993 /* And update the generations structures to match this */
1994 generations
[to
].lutexes
= generations
[from
].lutexes
;
1995 generations
[from
].lutexes
= NULL
;
1999 scav_lutex(lispobj
*where
, lispobj object
)
2001 mark_lutex((lispobj
) where
);
2003 return CEILING(sizeof(struct lutex
)/sizeof(lispobj
), 2);
2007 trans_lutex(lispobj object
)
2009 struct lutex
*lutex
= (struct lutex
*) native_pointer(object
);
2011 size_t words
= CEILING(sizeof(struct lutex
)/sizeof(lispobj
), 2);
2012 gc_assert(is_lisp_pointer(object
));
2013 copied
= copy_object(object
, words
);
2015 /* Update the links, since the lutex moved in memory. */
2017 lutex
->next
->prev
= (struct lutex
*) native_pointer(copied
);
2021 lutex
->prev
->next
= (struct lutex
*) native_pointer(copied
);
2023 generations
[lutex
->gen
].lutexes
=
2024 (struct lutex
*) native_pointer(copied
);
2031 size_lutex(lispobj
*where
)
2033 return CEILING(sizeof(struct lutex
)/sizeof(lispobj
), 2);
2035 #endif /* LUTEX_WIDETAG */
2042 /* XX This is a hack adapted from cgc.c. These don't work too
2043 * efficiently with the gencgc as a list of the weak pointers is
2044 * maintained within the objects which causes writes to the pages. A
2045 * limited attempt is made to avoid unnecessary writes, but this needs
2047 #define WEAK_POINTER_NWORDS \
2048 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
2051 scav_weak_pointer(lispobj
*where
, lispobj object
)
2053 /* Since we overwrite the 'next' field, we have to make
2054 * sure not to do so for pointers already in the list.
2055 * Instead of searching the list of weak_pointers each
2056 * time, we ensure that next is always NULL when the weak
2057 * pointer isn't in the list, and not NULL otherwise.
2058 * Since we can't use NULL to denote end of list, we
2059 * use a pointer back to the same weak_pointer.
2061 struct weak_pointer
* wp
= (struct weak_pointer
*)where
;
2063 if (NULL
== wp
->next
) {
2064 wp
->next
= weak_pointers
;
2066 if (NULL
== wp
->next
)
2070 /* Do not let GC scavenge the value slot of the weak pointer.
2071 * (That is why it is a weak pointer.) */
2073 return WEAK_POINTER_NWORDS
;
2078 search_read_only_space(void *pointer
)
2080 lispobj
*start
= (lispobj
*) READ_ONLY_SPACE_START
;
2081 lispobj
*end
= (lispobj
*) SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0);
2082 if ((pointer
< (void *)start
) || (pointer
>= (void *)end
))
2084 return (gc_search_space(start
,
2085 (((lispobj
*)pointer
)+2)-start
,
2086 (lispobj
*) pointer
));
2090 search_static_space(void *pointer
)
2092 lispobj
*start
= (lispobj
*)STATIC_SPACE_START
;
2093 lispobj
*end
= (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0);
2094 if ((pointer
< (void *)start
) || (pointer
>= (void *)end
))
2096 return (gc_search_space(start
,
2097 (((lispobj
*)pointer
)+2)-start
,
2098 (lispobj
*) pointer
));
2101 /* a faster version for searching the dynamic space. This will work even
2102 * if the object is in a current allocation region. */
2104 search_dynamic_space(void *pointer
)
2106 page_index_t page_index
= find_page_index(pointer
);
2109 /* The address may be invalid, so do some checks. */
2110 if ((page_index
== -1) ||
2111 (page_table
[page_index
].allocated
== FREE_PAGE_FLAG
))
2113 start
= (lispobj
*)((void *)page_address(page_index
)
2114 + page_table
[page_index
].first_object_offset
);
2115 return (gc_search_space(start
,
2116 (((lispobj
*)pointer
)+2)-start
,
2117 (lispobj
*)pointer
));
2120 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
2122 /* Helper for valid_lisp_pointer_p and
2123 * possibly_valid_dynamic_space_pointer.
2125 * pointer is the pointer to validate, and start_addr is the address
2126 * of the enclosing object.
2129 looks_like_valid_lisp_pointer_p(lispobj
*pointer
, lispobj
*start_addr
)
2131 /* We need to allow raw pointers into Code objects for return
2132 * addresses. This will also pick up pointers to functions in code
2134 if (widetag_of(*start_addr
) == CODE_HEADER_WIDETAG
)
2135 /* XXX could do some further checks here */
2138 if (!is_lisp_pointer((lispobj
)pointer
)) {
2142 /* Check that the object pointed to is consistent with the pointer
2144 switch (lowtag_of((lispobj
)pointer
)) {
2145 case FUN_POINTER_LOWTAG
:
2146 /* Start_addr should be the enclosing code object, or a closure
2148 switch (widetag_of(*start_addr
)) {
2149 case CODE_HEADER_WIDETAG
:
2150 /* This case is probably caught above. */
2152 case CLOSURE_HEADER_WIDETAG
:
2153 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
2154 if ((unsigned long)pointer
!=
2155 ((unsigned long)start_addr
+FUN_POINTER_LOWTAG
)) {
2159 pointer
, start_addr
, *start_addr
));
2167 pointer
, start_addr
, *start_addr
));
2171 case LIST_POINTER_LOWTAG
:
2172 if ((unsigned long)pointer
!=
2173 ((unsigned long)start_addr
+LIST_POINTER_LOWTAG
)) {
2177 pointer
, start_addr
, *start_addr
));
2180 /* Is it plausible cons? */
2181 if ((is_lisp_pointer(start_addr
[0])
2182 || (fixnump(start_addr
[0]))
2183 || (widetag_of(start_addr
[0]) == CHARACTER_WIDETAG
)
2184 #if N_WORD_BITS == 64
2185 || (widetag_of(start_addr
[0]) == SINGLE_FLOAT_WIDETAG
)
2187 || (widetag_of(start_addr
[0]) == UNBOUND_MARKER_WIDETAG
))
2188 && (is_lisp_pointer(start_addr
[1])
2189 || (fixnump(start_addr
[1]))
2190 || (widetag_of(start_addr
[1]) == CHARACTER_WIDETAG
)
2191 #if N_WORD_BITS == 64
2192 || (widetag_of(start_addr
[1]) == SINGLE_FLOAT_WIDETAG
)
2194 || (widetag_of(start_addr
[1]) == UNBOUND_MARKER_WIDETAG
)))
2200 pointer
, start_addr
, *start_addr
));
2203 case INSTANCE_POINTER_LOWTAG
:
2204 if ((unsigned long)pointer
!=
2205 ((unsigned long)start_addr
+INSTANCE_POINTER_LOWTAG
)) {
2209 pointer
, start_addr
, *start_addr
));
2212 if (widetag_of(start_addr
[0]) != INSTANCE_HEADER_WIDETAG
) {
2216 pointer
, start_addr
, *start_addr
));
2220 case OTHER_POINTER_LOWTAG
:
2221 if ((unsigned long)pointer
!=
2222 ((unsigned long)start_addr
+OTHER_POINTER_LOWTAG
)) {
2226 pointer
, start_addr
, *start_addr
));
2229 /* Is it plausible? Not a cons. XXX should check the headers. */
2230 if (is_lisp_pointer(start_addr
[0]) || ((start_addr
[0] & 3) == 0)) {
2234 pointer
, start_addr
, *start_addr
));
2237 switch (widetag_of(start_addr
[0])) {
2238 case UNBOUND_MARKER_WIDETAG
:
2239 case NO_TLS_VALUE_MARKER_WIDETAG
:
2240 case CHARACTER_WIDETAG
:
2241 #if N_WORD_BITS == 64
2242 case SINGLE_FLOAT_WIDETAG
:
2247 pointer
, start_addr
, *start_addr
));
2250 /* only pointed to by function pointers? */
2251 case CLOSURE_HEADER_WIDETAG
:
2252 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
2256 pointer
, start_addr
, *start_addr
));
2259 case INSTANCE_HEADER_WIDETAG
:
2263 pointer
, start_addr
, *start_addr
));
2266 /* the valid other immediate pointer objects */
2267 case SIMPLE_VECTOR_WIDETAG
:
2269 case COMPLEX_WIDETAG
:
2270 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
2271 case COMPLEX_SINGLE_FLOAT_WIDETAG
:
2273 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
2274 case COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2276 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
2277 case COMPLEX_LONG_FLOAT_WIDETAG
:
2279 case SIMPLE_ARRAY_WIDETAG
:
2280 case COMPLEX_BASE_STRING_WIDETAG
:
2281 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
2282 case COMPLEX_CHARACTER_STRING_WIDETAG
:
2284 case COMPLEX_VECTOR_NIL_WIDETAG
:
2285 case COMPLEX_BIT_VECTOR_WIDETAG
:
2286 case COMPLEX_VECTOR_WIDETAG
:
2287 case COMPLEX_ARRAY_WIDETAG
:
2288 case VALUE_CELL_HEADER_WIDETAG
:
2289 case SYMBOL_HEADER_WIDETAG
:
2291 case CODE_HEADER_WIDETAG
:
2292 case BIGNUM_WIDETAG
:
2293 #if N_WORD_BITS != 64
2294 case SINGLE_FLOAT_WIDETAG
:
2296 case DOUBLE_FLOAT_WIDETAG
:
2297 #ifdef LONG_FLOAT_WIDETAG
2298 case LONG_FLOAT_WIDETAG
:
2300 case SIMPLE_BASE_STRING_WIDETAG
:
2301 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2302 case SIMPLE_CHARACTER_STRING_WIDETAG
:
2304 case SIMPLE_BIT_VECTOR_WIDETAG
:
2305 case SIMPLE_ARRAY_NIL_WIDETAG
:
2306 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
2307 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
2308 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
2309 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
2310 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
2311 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
2312 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2313 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
2315 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
2316 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
2317 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2318 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
2320 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2321 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
2323 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2324 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
2326 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2327 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
2329 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2330 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
2332 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2333 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
2335 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2336 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
2338 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2339 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
2341 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2342 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
2344 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
2345 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
2346 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2347 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
2349 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2350 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
2352 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2353 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2355 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2356 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
2359 case WEAK_POINTER_WIDETAG
:
2360 #ifdef LUTEX_WIDETAG
2369 pointer
, start_addr
, *start_addr
));
2377 pointer
, start_addr
, *start_addr
));
2385 /* Used by the debugger to validate possibly bogus pointers before
2386 * calling MAKE-LISP-OBJ on them.
2388 * FIXME: We would like to make this perfect, because if the debugger
2389 * constructs a reference to a bugs lisp object, and it ends up in a
2390 * location scavenged by the GC all hell breaks loose.
2392 * Whereas possibly_valid_dynamic_space_pointer has to be conservative
2393 * and return true for all valid pointers, this could actually be eager
2394 * and lie about a few pointers without bad results... but that should
2395 * be reflected in the name.
2398 valid_lisp_pointer_p(lispobj
*pointer
)
2401 if (((start
=search_dynamic_space(pointer
))!=NULL
) ||
2402 ((start
=search_static_space(pointer
))!=NULL
) ||
2403 ((start
=search_read_only_space(pointer
))!=NULL
))
2404 return looks_like_valid_lisp_pointer_p(pointer
, start
);
2409 /* Is there any possibility that pointer is a valid Lisp object
2410 * reference, and/or something else (e.g. subroutine call return
2411 * address) which should prevent us from moving the referred-to thing?
2412 * This is called from preserve_pointers() */
2414 possibly_valid_dynamic_space_pointer(lispobj
*pointer
)
2416 lispobj
*start_addr
;
2418 /* Find the object start address. */
2419 if ((start_addr
= search_dynamic_space(pointer
)) == NULL
) {
2423 return looks_like_valid_lisp_pointer_p(pointer
, start_addr
);
2426 /* Adjust large bignum and vector objects. This will adjust the
2427 * allocated region if the size has shrunk, and move unboxed objects
2428 * into unboxed pages. The pages are not promoted here, and the
2429 * promoted region is not added to the new_regions; this is really
2430 * only designed to be called from preserve_pointer(). Shouldn't fail
2431 * if this is missed, just may delay the moving of objects to unboxed
2432 * pages, and the freeing of pages. */
2434 maybe_adjust_large_object(lispobj
*where
)
2436 page_index_t first_page
;
2437 page_index_t next_page
;
2440 long remaining_bytes
;
2442 long old_bytes_used
;
2446 /* Check whether it's a vector or bignum object. */
2447 switch (widetag_of(where
[0])) {
2448 case SIMPLE_VECTOR_WIDETAG
:
2449 boxed
= BOXED_PAGE_FLAG
;
2451 case BIGNUM_WIDETAG
:
2452 case SIMPLE_BASE_STRING_WIDETAG
:
2453 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2454 case SIMPLE_CHARACTER_STRING_WIDETAG
:
2456 case SIMPLE_BIT_VECTOR_WIDETAG
:
2457 case SIMPLE_ARRAY_NIL_WIDETAG
:
2458 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
2459 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
2460 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
2461 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
2462 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
2463 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
2464 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2465 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
2467 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
2468 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
2469 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2470 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
2472 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2473 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
2475 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2476 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
2478 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2479 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
2481 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2482 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
2484 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2485 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
2487 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2488 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
2490 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2491 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
2493 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2494 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
2496 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
2497 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
2498 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2499 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
2501 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2502 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
2504 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2505 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2507 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2508 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
2510 boxed
= UNBOXED_PAGE_FLAG
;
2516 /* Find its current size. */
2517 nwords
= (sizetab
[widetag_of(where
[0])])(where
);
2519 first_page
= find_page_index((void *)where
);
2520 gc_assert(first_page
>= 0);
2522 /* Note: Any page write-protection must be removed, else a later
2523 * scavenge_newspace may incorrectly not scavenge these pages.
2524 * This would not be necessary if they are added to the new areas,
2525 * but lets do it for them all (they'll probably be written
2528 gc_assert(page_table
[first_page
].first_object_offset
== 0);
2530 next_page
= first_page
;
2531 remaining_bytes
= nwords
*N_WORD_BYTES
;
2532 while (remaining_bytes
> PAGE_BYTES
) {
2533 gc_assert(page_table
[next_page
].gen
== from_space
);
2534 gc_assert((page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)
2535 || (page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
));
2536 gc_assert(page_table
[next_page
].large_object
);
2537 gc_assert(page_table
[next_page
].first_object_offset
==
2538 -PAGE_BYTES
*(next_page
-first_page
));
2539 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
2541 page_table
[next_page
].allocated
= boxed
;
2543 /* Shouldn't be write-protected at this stage. Essential that the
2545 gc_assert(!page_table
[next_page
].write_protected
);
2546 remaining_bytes
-= PAGE_BYTES
;
2550 /* Now only one page remains, but the object may have shrunk so
2551 * there may be more unused pages which will be freed. */
2553 /* Object may have shrunk but shouldn't have grown - check. */
2554 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
2556 page_table
[next_page
].allocated
= boxed
;
2557 gc_assert(page_table
[next_page
].allocated
==
2558 page_table
[first_page
].allocated
);
2560 /* Adjust the bytes_used. */
2561 old_bytes_used
= page_table
[next_page
].bytes_used
;
2562 page_table
[next_page
].bytes_used
= remaining_bytes
;
2564 bytes_freed
= old_bytes_used
- remaining_bytes
;
2566 /* Free any remaining pages; needs care. */
2568 while ((old_bytes_used
== PAGE_BYTES
) &&
2569 (page_table
[next_page
].gen
== from_space
) &&
2570 ((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
2571 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)) &&
2572 page_table
[next_page
].large_object
&&
2573 (page_table
[next_page
].first_object_offset
==
2574 -(next_page
- first_page
)*PAGE_BYTES
)) {
2575 /* It checks out OK, free the page. We don't need to both zeroing
2576 * pages as this should have been done before shrinking the
2577 * object. These pages shouldn't be write protected as they
2578 * should be zero filled. */
2579 gc_assert(page_table
[next_page
].write_protected
== 0);
2581 old_bytes_used
= page_table
[next_page
].bytes_used
;
2582 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
2583 page_table
[next_page
].bytes_used
= 0;
2584 bytes_freed
+= old_bytes_used
;
2588 if ((bytes_freed
> 0) && gencgc_verbose
) {
2590 "/maybe_adjust_large_object() freed %d\n",
2594 generations
[from_space
].bytes_allocated
-= bytes_freed
;
2595 bytes_allocated
-= bytes_freed
;
2600 /* Take a possible pointer to a Lisp object and mark its page in the
2601 * page_table so that it will not be relocated during a GC.
2603 * This involves locating the page it points to, then backing up to
2604 * the start of its region, then marking all pages dont_move from there
2605 * up to the first page that's not full or has a different generation
2607 * It is assumed that all the page static flags have been cleared at
2608 * the start of a GC.
2610 * It is also assumed that the current gc_alloc() region has been
2611 * flushed and the tables updated. */
2614 preserve_pointer(void *addr
)
2616 page_index_t addr_page_index
= find_page_index(addr
);
2617 page_index_t first_page
;
2619 unsigned int region_allocation
;
2621 /* quick check 1: Address is quite likely to have been invalid. */
2622 if ((addr_page_index
== -1)
2623 || (page_table
[addr_page_index
].allocated
== FREE_PAGE_FLAG
)
2624 || (page_table
[addr_page_index
].bytes_used
== 0)
2625 || (page_table
[addr_page_index
].gen
!= from_space
)
2626 /* Skip if already marked dont_move. */
2627 || (page_table
[addr_page_index
].dont_move
!= 0))
2629 gc_assert(!(page_table
[addr_page_index
].allocated
&OPEN_REGION_PAGE_FLAG
));
2630 /* (Now that we know that addr_page_index is in range, it's
2631 * safe to index into page_table[] with it.) */
2632 region_allocation
= page_table
[addr_page_index
].allocated
;
2634 /* quick check 2: Check the offset within the page.
2637 if (((unsigned long)addr
& (PAGE_BYTES
- 1)) > page_table
[addr_page_index
].bytes_used
)
2640 /* Filter out anything which can't be a pointer to a Lisp object
2641 * (or, as a special case which also requires dont_move, a return
2642 * address referring to something in a CodeObject). This is
2643 * expensive but important, since it vastly reduces the
2644 * probability that random garbage will be bogusly interpreted as
2645 * a pointer which prevents a page from moving. */
2646 if (!(possibly_valid_dynamic_space_pointer(addr
)))
2649 /* Find the beginning of the region. Note that there may be
2650 * objects in the region preceding the one that we were passed a
2651 * pointer to: if this is the case, we will write-protect all the
2652 * previous objects' pages too. */
2655 /* I think this'd work just as well, but without the assertions.
2656 * -dan 2004.01.01 */
2658 find_page_index(page_address(addr_page_index
)+
2659 page_table
[addr_page_index
].first_object_offset
);
2661 first_page
= addr_page_index
;
2662 while (page_table
[first_page
].first_object_offset
!= 0) {
2664 /* Do some checks. */
2665 gc_assert(page_table
[first_page
].bytes_used
== PAGE_BYTES
);
2666 gc_assert(page_table
[first_page
].gen
== from_space
);
2667 gc_assert(page_table
[first_page
].allocated
== region_allocation
);
2671 /* Adjust any large objects before promotion as they won't be
2672 * copied after promotion. */
2673 if (page_table
[first_page
].large_object
) {
2674 maybe_adjust_large_object(page_address(first_page
));
2675 /* If a large object has shrunk then addr may now point to a
2676 * free area in which case it's ignored here. Note it gets
2677 * through the valid pointer test above because the tail looks
2679 if ((page_table
[addr_page_index
].allocated
== FREE_PAGE_FLAG
)
2680 || (page_table
[addr_page_index
].bytes_used
== 0)
2681 /* Check the offset within the page. */
2682 || (((unsigned long)addr
& (PAGE_BYTES
- 1))
2683 > page_table
[addr_page_index
].bytes_used
)) {
2685 "weird? ignore ptr 0x%x to freed area of large object\n",
2689 /* It may have moved to unboxed pages. */
2690 region_allocation
= page_table
[first_page
].allocated
;
2693 /* Now work forward until the end of this contiguous area is found,
2694 * marking all pages as dont_move. */
2695 for (i
= first_page
; ;i
++) {
2696 gc_assert(page_table
[i
].allocated
== region_allocation
);
2698 /* Mark the page static. */
2699 page_table
[i
].dont_move
= 1;
2701 /* Move the page to the new_space. XX I'd rather not do this
2702 * but the GC logic is not quite able to copy with the static
2703 * pages remaining in the from space. This also requires the
2704 * generation bytes_allocated counters be updated. */
2705 page_table
[i
].gen
= new_space
;
2706 generations
[new_space
].bytes_allocated
+= page_table
[i
].bytes_used
;
2707 generations
[from_space
].bytes_allocated
-= page_table
[i
].bytes_used
;
2709 /* It is essential that the pages are not write protected as
2710 * they may have pointers into the old-space which need
2711 * scavenging. They shouldn't be write protected at this
2713 gc_assert(!page_table
[i
].write_protected
);
2715 /* Check whether this is the last page in this contiguous block.. */
2716 if ((page_table
[i
].bytes_used
< PAGE_BYTES
)
2717 /* ..or it is PAGE_BYTES and is the last in the block */
2718 || (page_table
[i
+1].allocated
== FREE_PAGE_FLAG
)
2719 || (page_table
[i
+1].bytes_used
== 0) /* next page free */
2720 || (page_table
[i
+1].gen
!= from_space
) /* diff. gen */
2721 || (page_table
[i
+1].first_object_offset
== 0))
2725 /* Check that the page is now static. */
2726 gc_assert(page_table
[addr_page_index
].dont_move
!= 0);
2729 #endif // defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
2732 /* If the given page is not write-protected, then scan it for pointers
2733 * to younger generations or the top temp. generation, if no
2734 * suspicious pointers are found then the page is write-protected.
2736 * Care is taken to check for pointers to the current gc_alloc()
2737 * region if it is a younger generation or the temp. generation. This
2738 * frees the caller from doing a gc_alloc_update_page_tables(). Actually
2739 * the gc_alloc_generation does not need to be checked as this is only
2740 * called from scavenge_generation() when the gc_alloc generation is
2741 * younger, so it just checks if there is a pointer to the current
2744 * We return 1 if the page was write-protected, else 0. */
2746 update_page_write_prot(page_index_t page
)
2748 generation_index_t gen
= page_table
[page
].gen
;
2751 void **page_addr
= (void **)page_address(page
);
2752 long num_words
= page_table
[page
].bytes_used
/ N_WORD_BYTES
;
2754 /* Shouldn't be a free page. */
2755 gc_assert(page_table
[page
].allocated
!= FREE_PAGE_FLAG
);
2756 gc_assert(page_table
[page
].bytes_used
!= 0);
2758 /* Skip if it's already write-protected, pinned, or unboxed */
2759 if (page_table
[page
].write_protected
2760 /* FIXME: What's the reason for not write-protecting pinned pages? */
2761 || page_table
[page
].dont_move
2762 || (page_table
[page
].allocated
& UNBOXED_PAGE_FLAG
))
2765 /* Scan the page for pointers to younger generations or the
2766 * top temp. generation. */
2768 for (j
= 0; j
< num_words
; j
++) {
2769 void *ptr
= *(page_addr
+j
);
2770 page_index_t index
= find_page_index(ptr
);
2772 /* Check that it's in the dynamic space */
2774 if (/* Does it point to a younger or the temp. generation? */
2775 ((page_table
[index
].allocated
!= FREE_PAGE_FLAG
)
2776 && (page_table
[index
].bytes_used
!= 0)
2777 && ((page_table
[index
].gen
< gen
)
2778 || (page_table
[index
].gen
== SCRATCH_GENERATION
)))
2780 /* Or does it point within a current gc_alloc() region? */
2781 || ((boxed_region
.start_addr
<= ptr
)
2782 && (ptr
<= boxed_region
.free_pointer
))
2783 || ((unboxed_region
.start_addr
<= ptr
)
2784 && (ptr
<= unboxed_region
.free_pointer
))) {
2791 /* Write-protect the page. */
2792 /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
2794 os_protect((void *)page_addr
,
2796 OS_VM_PROT_READ
|OS_VM_PROT_EXECUTE
);
2798 /* Note the page as protected in the page tables. */
2799 page_table
[page
].write_protected
= 1;
2805 /* Scavenge all generations from FROM to TO, inclusive, except for
2806 * new_space which needs special handling, as new objects may be
2807 * added which are not checked here - use scavenge_newspace generation.
2809 * Write-protected pages should not have any pointers to the
2810 * from_space so do need scavenging; thus write-protected pages are
2811 * not always scavenged. There is some code to check that these pages
2812 * are not written; but to check fully the write-protected pages need
2813 * to be scavenged by disabling the code to skip them.
2815 * Under the current scheme when a generation is GCed the younger
2816 * generations will be empty. So, when a generation is being GCed it
2817 * is only necessary to scavenge the older generations for pointers
2818 * not the younger. So a page that does not have pointers to younger
2819 * generations does not need to be scavenged.
2821 * The write-protection can be used to note pages that don't have
2822 * pointers to younger pages. But pages can be written without having
2823 * pointers to younger generations. After the pages are scavenged here
2824 * they can be scanned for pointers to younger generations and if
2825 * there are none the page can be write-protected.
2827 * One complication is when the newspace is the top temp. generation.
2829 * Enabling SC_GEN_CK scavenges the write-protected pages and checks
2830 * that none were written, which they shouldn't be as they should have
2831 * no pointers to younger generations. This breaks down for weak
2832 * pointers as the objects contain a link to the next and are written
2833 * if a weak pointer is scavenged. Still it's a useful check. */
2835 scavenge_generations(generation_index_t from
, generation_index_t to
)
2842 /* Clear the write_protected_cleared flags on all pages. */
2843 for (i
= 0; i
< page_table_pages
; i
++)
2844 page_table
[i
].write_protected_cleared
= 0;
2847 for (i
= 0; i
< last_free_page
; i
++) {
2848 generation_index_t generation
= page_table
[i
].gen
;
2849 if ((page_table
[i
].allocated
& BOXED_PAGE_FLAG
)
2850 && (page_table
[i
].bytes_used
!= 0)
2851 && (generation
!= new_space
)
2852 && (generation
>= from
)
2853 && (generation
<= to
)) {
2854 page_index_t last_page
,j
;
2855 int write_protected
=1;
2857 /* This should be the start of a region */
2858 gc_assert(page_table
[i
].first_object_offset
== 0);
2860 /* Now work forward until the end of the region */
2861 for (last_page
= i
; ; last_page
++) {
2863 write_protected
&& page_table
[last_page
].write_protected
;
2864 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
2865 /* Or it is PAGE_BYTES and is the last in the block */
2866 || (!(page_table
[last_page
+1].allocated
& BOXED_PAGE_FLAG
))
2867 || (page_table
[last_page
+1].bytes_used
== 0)
2868 || (page_table
[last_page
+1].gen
!= generation
)
2869 || (page_table
[last_page
+1].first_object_offset
== 0))
2872 if (!write_protected
) {
2873 scavenge(page_address(i
),
2874 (page_table
[last_page
].bytes_used
+
2875 (last_page
-i
)*PAGE_BYTES
)/N_WORD_BYTES
);
2877 /* Now scan the pages and write protect those that
2878 * don't have pointers to younger generations. */
2879 if (enable_page_protection
) {
2880 for (j
= i
; j
<= last_page
; j
++) {
2881 num_wp
+= update_page_write_prot(j
);
2884 if ((gencgc_verbose
> 1) && (num_wp
!= 0)) {
2886 "/write protected %d pages within generation %d\n",
2887 num_wp
, generation
));
2895 /* Check that none of the write_protected pages in this generation
2896 * have been written to. */
2897 for (i
= 0; i
< page_table_pages
; i
++) {
2898 if ((page_table
[i
].allocation
!= FREE_PAGE_FLAG
)
2899 && (page_table
[i
].bytes_used
!= 0)
2900 && (page_table
[i
].gen
== generation
)
2901 && (page_table
[i
].write_protected_cleared
!= 0)) {
2902 FSHOW((stderr
, "/scavenge_generation() %d\n", generation
));
2904 "/page bytes_used=%d first_object_offset=%d dont_move=%d\n",
2905 page_table
[i
].bytes_used
,
2906 page_table
[i
].first_object_offset
,
2907 page_table
[i
].dont_move
));
2908 lose("write to protected page %d in scavenge_generation()\n", i
);
2915 /* Scavenge a newspace generation. As it is scavenged new objects may
2916 * be allocated to it; these will also need to be scavenged. This
2917 * repeats until there are no more objects unscavenged in the
2918 * newspace generation.
2920 * To help improve the efficiency, areas written are recorded by
2921 * gc_alloc() and only these scavenged. Sometimes a little more will be
2922 * scavenged, but this causes no harm. An easy check is done that the
2923 * scavenged bytes equals the number allocated in the previous
2926 * Write-protected pages are not scanned except if they are marked
2927 * dont_move in which case they may have been promoted and still have
2928 * pointers to the from space.
2930 * Write-protected pages could potentially be written by alloc however
2931 * to avoid having to handle re-scavenging of write-protected pages
2932 * gc_alloc() does not write to write-protected pages.
2934 * New areas of objects allocated are recorded alternatively in the two
2935 * new_areas arrays below. */
2936 static struct new_area new_areas_1
[NUM_NEW_AREAS
];
2937 static struct new_area new_areas_2
[NUM_NEW_AREAS
];
2939 /* Do one full scan of the new space generation. This is not enough to
2940 * complete the job as new objects may be added to the generation in
2941 * the process which are not scavenged. */
2943 scavenge_newspace_generation_one_scan(generation_index_t generation
)
2948 "/starting one full scan of newspace generation %d\n",
2950 for (i
= 0; i
< last_free_page
; i
++) {
2951 /* Note that this skips over open regions when it encounters them. */
2952 if ((page_table
[i
].allocated
& BOXED_PAGE_FLAG
)
2953 && (page_table
[i
].bytes_used
!= 0)
2954 && (page_table
[i
].gen
== generation
)
2955 && ((page_table
[i
].write_protected
== 0)
2956 /* (This may be redundant as write_protected is now
2957 * cleared before promotion.) */
2958 || (page_table
[i
].dont_move
== 1))) {
2959 page_index_t last_page
;
2962 /* The scavenge will start at the first_object_offset of page i.
2964 * We need to find the full extent of this contiguous
2965 * block in case objects span pages.
2967 * Now work forward until the end of this contiguous area
2968 * is found. A small area is preferred as there is a
2969 * better chance of its pages being write-protected. */
2970 for (last_page
= i
; ;last_page
++) {
2971 /* If all pages are write-protected and movable,
2972 * then no need to scavenge */
2973 all_wp
=all_wp
&& page_table
[last_page
].write_protected
&&
2974 !page_table
[last_page
].dont_move
;
2976 /* Check whether this is the last page in this
2977 * contiguous block */
2978 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
2979 /* Or it is PAGE_BYTES and is the last in the block */
2980 || (!(page_table
[last_page
+1].allocated
& BOXED_PAGE_FLAG
))
2981 || (page_table
[last_page
+1].bytes_used
== 0)
2982 || (page_table
[last_page
+1].gen
!= generation
)
2983 || (page_table
[last_page
+1].first_object_offset
== 0))
2987 /* Do a limited check for write-protected pages. */
2991 size
= (page_table
[last_page
].bytes_used
2992 + (last_page
-i
)*PAGE_BYTES
2993 - page_table
[i
].first_object_offset
)/N_WORD_BYTES
;
2994 new_areas_ignore_page
= last_page
;
2996 scavenge(page_address(i
) +
2997 page_table
[i
].first_object_offset
,
3005 "/done with one full scan of newspace generation %d\n",
3009 /* Do a complete scavenge of the newspace generation. */
3011 scavenge_newspace_generation(generation_index_t generation
)
3015 /* the new_areas array currently being written to by gc_alloc() */
3016 struct new_area (*current_new_areas
)[] = &new_areas_1
;
3017 long current_new_areas_index
;
3019 /* the new_areas created by the previous scavenge cycle */
3020 struct new_area (*previous_new_areas
)[] = NULL
;
3021 long previous_new_areas_index
;
3023 /* Flush the current regions updating the tables. */
3024 gc_alloc_update_all_page_tables();
3026 /* Turn on the recording of new areas by gc_alloc(). */
3027 new_areas
= current_new_areas
;
3028 new_areas_index
= 0;
3030 /* Don't need to record new areas that get scavenged anyway during
3031 * scavenge_newspace_generation_one_scan. */
3032 record_new_objects
= 1;
3034 /* Start with a full scavenge. */
3035 scavenge_newspace_generation_one_scan(generation
);
3037 /* Record all new areas now. */
3038 record_new_objects
= 2;
3040 /* Give a chance to weak hash tables to make other objects live.
3041 * FIXME: The algorithm implemented here for weak hash table gcing
3042 * is O(W^2+N) as Bruno Haible warns in
3043 * http://www.haible.de/bruno/papers/cs/weak/WeakDatastructures-writeup.html
3044 * see "Implementation 2". */
3045 scav_weak_hash_tables();
3047 /* Flush the current regions updating the tables. */
3048 gc_alloc_update_all_page_tables();
3050 /* Grab new_areas_index. */
3051 current_new_areas_index
= new_areas_index
;
3054 "The first scan is finished; current_new_areas_index=%d.\n",
3055 current_new_areas_index));*/
3057 while (current_new_areas_index
> 0) {
3058 /* Move the current to the previous new areas */
3059 previous_new_areas
= current_new_areas
;
3060 previous_new_areas_index
= current_new_areas_index
;
3062 /* Scavenge all the areas in previous new areas. Any new areas
3063 * allocated are saved in current_new_areas. */
3065 /* Allocate an array for current_new_areas; alternating between
3066 * new_areas_1 and 2 */
3067 if (previous_new_areas
== &new_areas_1
)
3068 current_new_areas
= &new_areas_2
;
3070 current_new_areas
= &new_areas_1
;
3072 /* Set up for gc_alloc(). */
3073 new_areas
= current_new_areas
;
3074 new_areas_index
= 0;
3076 /* Check whether previous_new_areas had overflowed. */
3077 if (previous_new_areas_index
>= NUM_NEW_AREAS
) {
3079 /* New areas of objects allocated have been lost so need to do a
3080 * full scan to be sure! If this becomes a problem try
3081 * increasing NUM_NEW_AREAS. */
3083 SHOW("new_areas overflow, doing full scavenge");
3085 /* Don't need to record new areas that get scavenged
3086 * anyway during scavenge_newspace_generation_one_scan. */
3087 record_new_objects
= 1;
3089 scavenge_newspace_generation_one_scan(generation
);
3091 /* Record all new areas now. */
3092 record_new_objects
= 2;
3094 scav_weak_hash_tables();
3096 /* Flush the current regions updating the tables. */
3097 gc_alloc_update_all_page_tables();
3101 /* Work through previous_new_areas. */
3102 for (i
= 0; i
< previous_new_areas_index
; i
++) {
3103 long page
= (*previous_new_areas
)[i
].page
;
3104 long offset
= (*previous_new_areas
)[i
].offset
;
3105 long size
= (*previous_new_areas
)[i
].size
/ N_WORD_BYTES
;
3106 gc_assert((*previous_new_areas
)[i
].size
% N_WORD_BYTES
== 0);
3107 scavenge(page_address(page
)+offset
, size
);
3110 scav_weak_hash_tables();
3112 /* Flush the current regions updating the tables. */
3113 gc_alloc_update_all_page_tables();
3116 current_new_areas_index
= new_areas_index
;
3119 "The re-scan has finished; current_new_areas_index=%d.\n",
3120 current_new_areas_index));*/
3123 /* Turn off recording of areas allocated by gc_alloc(). */
3124 record_new_objects
= 0;
3127 /* Check that none of the write_protected pages in this generation
3128 * have been written to. */
3129 for (i
= 0; i
< page_table_pages
; i
++) {
3130 if ((page_table
[i
].allocation
!= FREE_PAGE_FLAG
)
3131 && (page_table
[i
].bytes_used
!= 0)
3132 && (page_table
[i
].gen
== generation
)
3133 && (page_table
[i
].write_protected_cleared
!= 0)
3134 && (page_table
[i
].dont_move
== 0)) {
3135 lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d\n",
3136 i
, generation
, page_table
[i
].dont_move
);
3142 /* Un-write-protect all the pages in from_space. This is done at the
3143 * start of a GC else there may be many page faults while scavenging
3144 * the newspace (I've seen drive the system time to 99%). These pages
3145 * would need to be unprotected anyway before unmapping in
3146 * free_oldspace; not sure what effect this has on paging.. */
3148 unprotect_oldspace(void)
3152 for (i
= 0; i
< last_free_page
; i
++) {
3153 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
3154 && (page_table
[i
].bytes_used
!= 0)
3155 && (page_table
[i
].gen
== from_space
)) {
3158 page_start
= (void *)page_address(i
);
3160 /* Remove any write-protection. We should be able to rely
3161 * on the write-protect flag to avoid redundant calls. */
3162 if (page_table
[i
].write_protected
) {
3163 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
3164 page_table
[i
].write_protected
= 0;
3170 /* Work through all the pages and free any in from_space. This
3171 * assumes that all objects have been copied or promoted to an older
3172 * generation. Bytes_allocated and the generation bytes_allocated
3173 * counter are updated. The number of bytes freed is returned. */
3177 long bytes_freed
= 0;
3178 page_index_t first_page
, last_page
;
3183 /* Find a first page for the next region of pages. */
3184 while ((first_page
< last_free_page
)
3185 && ((page_table
[first_page
].allocated
== FREE_PAGE_FLAG
)
3186 || (page_table
[first_page
].bytes_used
== 0)
3187 || (page_table
[first_page
].gen
!= from_space
)))
3190 if (first_page
>= last_free_page
)
3193 /* Find the last page of this region. */
3194 last_page
= first_page
;
3197 /* Free the page. */
3198 bytes_freed
+= page_table
[last_page
].bytes_used
;
3199 generations
[page_table
[last_page
].gen
].bytes_allocated
-=
3200 page_table
[last_page
].bytes_used
;
3201 page_table
[last_page
].allocated
= FREE_PAGE_FLAG
;
3202 page_table
[last_page
].bytes_used
= 0;
3204 /* Remove any write-protection. We should be able to rely
3205 * on the write-protect flag to avoid redundant calls. */
3207 void *page_start
= (void *)page_address(last_page
);
3209 if (page_table
[last_page
].write_protected
) {
3210 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
3211 page_table
[last_page
].write_protected
= 0;
3216 while ((last_page
< last_free_page
)
3217 && (page_table
[last_page
].allocated
!= FREE_PAGE_FLAG
)
3218 && (page_table
[last_page
].bytes_used
!= 0)
3219 && (page_table
[last_page
].gen
== from_space
));
3221 #ifdef READ_PROTECT_FREE_PAGES
3222 os_protect(page_address(first_page
),
3223 PAGE_BYTES
*(last_page
-first_page
),
3226 first_page
= last_page
;
3227 } while (first_page
< last_free_page
);
3229 bytes_allocated
-= bytes_freed
;
3234 /* Print some information about a pointer at the given address. */
3236 print_ptr(lispobj
*addr
)
3238 /* If addr is in the dynamic space then out the page information. */
3239 page_index_t pi1
= find_page_index((void*)addr
);
3242 fprintf(stderr
," %x: page %d alloc %d gen %d bytes_used %d offset %d dont_move %d\n",
3243 (unsigned long) addr
,
3245 page_table
[pi1
].allocated
,
3246 page_table
[pi1
].gen
,
3247 page_table
[pi1
].bytes_used
,
3248 page_table
[pi1
].first_object_offset
,
3249 page_table
[pi1
].dont_move
);
3250 fprintf(stderr
," %x %x %x %x (%x) %x %x %x %x\n",
3264 verify_space(lispobj
*start
, size_t words
)
3266 int is_in_dynamic_space
= (find_page_index((void*)start
) != -1);
3267 int is_in_readonly_space
=
3268 (READ_ONLY_SPACE_START
<= (unsigned long)start
&&
3269 (unsigned long)start
< SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0));
3273 lispobj thing
= *(lispobj
*)start
;
3275 if (is_lisp_pointer(thing
)) {
3276 page_index_t page_index
= find_page_index((void*)thing
);
3277 long to_readonly_space
=
3278 (READ_ONLY_SPACE_START
<= thing
&&
3279 thing
< SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0));
3280 long to_static_space
=
3281 (STATIC_SPACE_START
<= thing
&&
3282 thing
< SymbolValue(STATIC_SPACE_FREE_POINTER
,0));
3284 /* Does it point to the dynamic space? */
3285 if (page_index
!= -1) {
3286 /* If it's within the dynamic space it should point to a used
3287 * page. XX Could check the offset too. */
3288 if ((page_table
[page_index
].allocated
!= FREE_PAGE_FLAG
)
3289 && (page_table
[page_index
].bytes_used
== 0))
3290 lose ("Ptr %x @ %x sees free page.\n", thing
, start
);
3291 /* Check that it doesn't point to a forwarding pointer! */
3292 if (*((lispobj
*)native_pointer(thing
)) == 0x01) {
3293 lose("Ptr %x @ %x sees forwarding ptr.\n", thing
, start
);
3295 /* Check that its not in the RO space as it would then be a
3296 * pointer from the RO to the dynamic space. */
3297 if (is_in_readonly_space
) {
3298 lose("ptr to dynamic space %x from RO space %x\n",
3301 /* Does it point to a plausible object? This check slows
3302 * it down a lot (so it's commented out).
3304 * "a lot" is serious: it ate 50 minutes cpu time on
3305 * my duron 950 before I came back from lunch and
3308 * FIXME: Add a variable to enable this
3311 if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
3312 lose("ptr %x to invalid object %x\n", thing, start);
3316 /* Verify that it points to another valid space. */
3317 if (!to_readonly_space
&& !to_static_space
) {
3318 lose("Ptr %x @ %x sees junk.\n", thing
, start
);
3322 if (!(fixnump(thing
))) {
3324 switch(widetag_of(*start
)) {
3327 case SIMPLE_VECTOR_WIDETAG
:
3329 case COMPLEX_WIDETAG
:
3330 case SIMPLE_ARRAY_WIDETAG
:
3331 case COMPLEX_BASE_STRING_WIDETAG
:
3332 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
3333 case COMPLEX_CHARACTER_STRING_WIDETAG
:
3335 case COMPLEX_VECTOR_NIL_WIDETAG
:
3336 case COMPLEX_BIT_VECTOR_WIDETAG
:
3337 case COMPLEX_VECTOR_WIDETAG
:
3338 case COMPLEX_ARRAY_WIDETAG
:
3339 case CLOSURE_HEADER_WIDETAG
:
3340 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
3341 case VALUE_CELL_HEADER_WIDETAG
:
3342 case SYMBOL_HEADER_WIDETAG
:
3343 case CHARACTER_WIDETAG
:
3344 #if N_WORD_BITS == 64
3345 case SINGLE_FLOAT_WIDETAG
:
3347 case UNBOUND_MARKER_WIDETAG
:
3352 case INSTANCE_HEADER_WIDETAG
:
3355 long ntotal
= HeaderValue(thing
);
3356 lispobj layout
= ((struct instance
*)start
)->slots
[0];
3361 nuntagged
= ((struct layout
*)native_pointer(layout
))->n_untagged_slots
;
3362 verify_space(start
+ 1, ntotal
- fixnum_value(nuntagged
));
3366 case CODE_HEADER_WIDETAG
:
3368 lispobj object
= *start
;
3370 long nheader_words
, ncode_words
, nwords
;
3372 struct simple_fun
*fheaderp
;
3374 code
= (struct code
*) start
;
3376 /* Check that it's not in the dynamic space.
3377 * FIXME: Isn't is supposed to be OK for code
3378 * objects to be in the dynamic space these days? */
3379 if (is_in_dynamic_space
3380 /* It's ok if it's byte compiled code. The trace
3381 * table offset will be a fixnum if it's x86
3382 * compiled code - check.
3384 * FIXME: #^#@@! lack of abstraction here..
3385 * This line can probably go away now that
3386 * there's no byte compiler, but I've got
3387 * too much to worry about right now to try
3388 * to make sure. -- WHN 2001-10-06 */
3389 && fixnump(code
->trace_table_offset
)
3390 /* Only when enabled */
3391 && verify_dynamic_code_check
) {
3393 "/code object at %x in the dynamic space\n",
3397 ncode_words
= fixnum_value(code
->code_size
);
3398 nheader_words
= HeaderValue(object
);
3399 nwords
= ncode_words
+ nheader_words
;
3400 nwords
= CEILING(nwords
, 2);
3401 /* Scavenge the boxed section of the code data block */
3402 verify_space(start
+ 1, nheader_words
- 1);
3404 /* Scavenge the boxed section of each function
3405 * object in the code data block. */
3406 fheaderl
= code
->entry_points
;
3407 while (fheaderl
!= NIL
) {
3409 (struct simple_fun
*) native_pointer(fheaderl
);
3410 gc_assert(widetag_of(fheaderp
->header
) == SIMPLE_FUN_HEADER_WIDETAG
);
3411 verify_space(&fheaderp
->name
, 1);
3412 verify_space(&fheaderp
->arglist
, 1);
3413 verify_space(&fheaderp
->type
, 1);
3414 fheaderl
= fheaderp
->next
;
3420 /* unboxed objects */
3421 case BIGNUM_WIDETAG
:
3422 #if N_WORD_BITS != 64
3423 case SINGLE_FLOAT_WIDETAG
:
3425 case DOUBLE_FLOAT_WIDETAG
:
3426 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3427 case LONG_FLOAT_WIDETAG
:
3429 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3430 case COMPLEX_SINGLE_FLOAT_WIDETAG
:
3432 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3433 case COMPLEX_DOUBLE_FLOAT_WIDETAG
:
3435 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3436 case COMPLEX_LONG_FLOAT_WIDETAG
:
3438 case SIMPLE_BASE_STRING_WIDETAG
:
3439 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
3440 case SIMPLE_CHARACTER_STRING_WIDETAG
:
3442 case SIMPLE_BIT_VECTOR_WIDETAG
:
3443 case SIMPLE_ARRAY_NIL_WIDETAG
:
3444 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
3445 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
3446 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
3447 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
3448 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
3449 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
3450 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
3451 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
3453 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
3454 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
3455 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
3456 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
3458 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
3459 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
3461 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
3462 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
3464 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3465 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
3467 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3468 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
3470 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3471 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
3473 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3474 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
3476 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
3477 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
3479 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
3480 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
3482 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
3483 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
3484 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3485 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
3487 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3488 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
3490 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3491 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
3493 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3494 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
3497 case WEAK_POINTER_WIDETAG
:
3498 #ifdef LUTEX_WIDETAG
3501 count
= (sizetab
[widetag_of(*start
)])(start
);
3506 "/Unhandled widetag 0x%x at 0x%x\n",
3507 widetag_of(*start
), start
));
3521 /* FIXME: It would be nice to make names consistent so that
3522 * foo_size meant size *in* *bytes* instead of size in some
3523 * arbitrary units. (Yes, this caused a bug, how did you guess?:-)
3524 * Some counts of lispobjs are called foo_count; it might be good
3525 * to grep for all foo_size and rename the appropriate ones to
3527 long read_only_space_size
=
3528 (lispobj
*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0)
3529 - (lispobj
*)READ_ONLY_SPACE_START
;
3530 long static_space_size
=
3531 (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0)
3532 - (lispobj
*)STATIC_SPACE_START
;
3534 for_each_thread(th
) {
3535 long binding_stack_size
=
3536 (lispobj
*)get_binding_stack_pointer(th
)
3537 - (lispobj
*)th
->binding_stack_start
;
3538 verify_space(th
->binding_stack_start
, binding_stack_size
);
3540 verify_space((lispobj
*)READ_ONLY_SPACE_START
, read_only_space_size
);
3541 verify_space((lispobj
*)STATIC_SPACE_START
, static_space_size
);
3545 verify_generation(generation_index_t generation
)
3549 for (i
= 0; i
< last_free_page
; i
++) {
3550 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
3551 && (page_table
[i
].bytes_used
!= 0)
3552 && (page_table
[i
].gen
== generation
)) {
3553 page_index_t last_page
;
3554 int region_allocation
= page_table
[i
].allocated
;
3556 /* This should be the start of a contiguous block */
3557 gc_assert(page_table
[i
].first_object_offset
== 0);
3559 /* Need to find the full extent of this contiguous block in case
3560 objects span pages. */
3562 /* Now work forward until the end of this contiguous area is
3564 for (last_page
= i
; ;last_page
++)
3565 /* Check whether this is the last page in this contiguous
3567 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
3568 /* Or it is PAGE_BYTES and is the last in the block */
3569 || (page_table
[last_page
+1].allocated
!= region_allocation
)
3570 || (page_table
[last_page
+1].bytes_used
== 0)
3571 || (page_table
[last_page
+1].gen
!= generation
)
3572 || (page_table
[last_page
+1].first_object_offset
== 0))
3575 verify_space(page_address(i
), (page_table
[last_page
].bytes_used
3576 + (last_page
-i
)*PAGE_BYTES
)/N_WORD_BYTES
);
3582 /* Check that all the free space is zero filled. */
3584 verify_zero_fill(void)
3588 for (page
= 0; page
< last_free_page
; page
++) {
3589 if (page_table
[page
].allocated
== FREE_PAGE_FLAG
) {
3590 /* The whole page should be zero filled. */
3591 long *start_addr
= (long *)page_address(page
);
3594 for (i
= 0; i
< size
; i
++) {
3595 if (start_addr
[i
] != 0) {
3596 lose("free page not zero at %x\n", start_addr
+ i
);
3600 long free_bytes
= PAGE_BYTES
- page_table
[page
].bytes_used
;
3601 if (free_bytes
> 0) {
3602 long *start_addr
= (long *)((unsigned long)page_address(page
)
3603 + page_table
[page
].bytes_used
);
3604 long size
= free_bytes
/ N_WORD_BYTES
;
3606 for (i
= 0; i
< size
; i
++) {
3607 if (start_addr
[i
] != 0) {
3608 lose("free region not zero at %x\n", start_addr
+ i
);
3616 /* External entry point for verify_zero_fill */
3618 gencgc_verify_zero_fill(void)
3620 /* Flush the alloc regions updating the tables. */
3621 gc_alloc_update_all_page_tables();
3622 SHOW("verifying zero fill");
3627 verify_dynamic_space(void)
3629 generation_index_t i
;
3631 for (i
= 0; i
<= HIGHEST_NORMAL_GENERATION
; i
++)
3632 verify_generation(i
);
3634 if (gencgc_enable_verify_zero_fill
)
3638 /* Write-protect all the dynamic boxed pages in the given generation. */
3640 write_protect_generation_pages(generation_index_t generation
)
3644 gc_assert(generation
< SCRATCH_GENERATION
);
3646 for (start
= 0; start
< last_free_page
; start
++) {
3647 if ((page_table
[start
].allocated
== BOXED_PAGE_FLAG
)
3648 && (page_table
[start
].bytes_used
!= 0)
3649 && !page_table
[start
].dont_move
3650 && (page_table
[start
].gen
== generation
)) {
3654 /* Note the page as protected in the page tables. */
3655 page_table
[start
].write_protected
= 1;
3657 for (last
= start
+ 1; last
< last_free_page
; last
++) {
3658 if ((page_table
[last
].allocated
!= BOXED_PAGE_FLAG
)
3659 || (page_table
[last
].bytes_used
== 0)
3660 || page_table
[last
].dont_move
3661 || (page_table
[last
].gen
!= generation
))
3663 page_table
[last
].write_protected
= 1;
3666 page_start
= (void *)page_address(start
);
3668 os_protect(page_start
,
3669 PAGE_BYTES
* (last
- start
),
3670 OS_VM_PROT_READ
| OS_VM_PROT_EXECUTE
);
3676 if (gencgc_verbose
> 1) {
3678 "/write protected %d of %d pages in generation %d\n",
3679 count_write_protect_generation_pages(generation
),
3680 count_generation_pages(generation
),
3685 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
3688 scavenge_control_stack()
3690 unsigned long control_stack_size
;
3692 /* This is going to be a big problem when we try to port threads
3694 struct thread
*th
= arch_os_get_current_thread();
3695 lispobj
*control_stack
=
3696 (lispobj
*)(th
->control_stack_start
);
3698 control_stack_size
= current_control_stack_pointer
- control_stack
;
3699 scavenge(control_stack
, control_stack_size
);
3702 /* Scavenging Interrupt Contexts */
3704 static int boxed_registers
[] = BOXED_REGISTERS
;
3707 scavenge_interrupt_context(os_context_t
* context
)
3713 unsigned long lip_offset
;
3714 int lip_register_pair
;
3716 unsigned long pc_code_offset
;
3718 #ifdef ARCH_HAS_LINK_REGISTER
3719 unsigned long lr_code_offset
;
3721 #ifdef ARCH_HAS_NPC_REGISTER
3722 unsigned long npc_code_offset
;
3726 /* Find the LIP's register pair and calculate it's offset */
3727 /* before we scavenge the context. */
3730 * I (RLT) think this is trying to find the boxed register that is
3731 * closest to the LIP address, without going past it. Usually, it's
3732 * reg_CODE or reg_LRA. But sometimes, nothing can be found.
3734 lip
= *os_context_register_addr(context
, reg_LIP
);
3735 lip_offset
= 0x7FFFFFFF;
3736 lip_register_pair
= -1;
3737 for (i
= 0; i
< (sizeof(boxed_registers
) / sizeof(int)); i
++) {
3742 index
= boxed_registers
[i
];
3743 reg
= *os_context_register_addr(context
, index
);
3744 if ((reg
& ~((1L<<N_LOWTAG_BITS
)-1)) <= lip
) {
3746 if (offset
< lip_offset
) {
3747 lip_offset
= offset
;
3748 lip_register_pair
= index
;
3752 #endif /* reg_LIP */
3754 /* Compute the PC's offset from the start of the CODE */
3756 pc_code_offset
= *os_context_pc_addr(context
) - *os_context_register_addr(context
, reg_CODE
);
3757 #ifdef ARCH_HAS_NPC_REGISTER
3758 npc_code_offset
= *os_context_npc_addr(context
) - *os_context_register_addr(context
, reg_CODE
);
3759 #endif /* ARCH_HAS_NPC_REGISTER */
3761 #ifdef ARCH_HAS_LINK_REGISTER
3763 *os_context_lr_addr(context
) -
3764 *os_context_register_addr(context
, reg_CODE
);
3767 /* Scanvenge all boxed registers in the context. */
3768 for (i
= 0; i
< (sizeof(boxed_registers
) / sizeof(int)); i
++) {
3772 index
= boxed_registers
[i
];
3773 foo
= *os_context_register_addr(context
, index
);
3775 *os_context_register_addr(context
, index
) = foo
;
3777 scavenge((lispobj
*) &(*os_context_register_addr(context
, index
)), 1);
3784 * But what happens if lip_register_pair is -1? *os_context_register_addr on Solaris
3785 * (see solaris_register_address in solaris-os.c) will return
3786 * &context->uc_mcontext.gregs[2]. But gregs[2] is REG_nPC. Is
3787 * that what we really want? My guess is that that is not what we
3788 * want, so if lip_register_pair is -1, we don't touch reg_LIP at
3789 * all. But maybe it doesn't really matter if LIP is trashed?
3791 if (lip_register_pair
>= 0) {
3792 *os_context_register_addr(context
, reg_LIP
) =
3793 *os_context_register_addr(context
, lip_register_pair
) + lip_offset
;
3795 #endif /* reg_LIP */
3797 /* Fix the PC if it was in from space */
3798 if (from_space_p(*os_context_pc_addr(context
)))
3799 *os_context_pc_addr(context
) = *os_context_register_addr(context
, reg_CODE
) + pc_code_offset
;
3801 #ifdef ARCH_HAS_LINK_REGISTER
3802 /* Fix the LR ditto; important if we're being called from
3803 * an assembly routine that expects to return using blr, otherwise
3805 if (from_space_p(*os_context_lr_addr(context
)))
3806 *os_context_lr_addr(context
) =
3807 *os_context_register_addr(context
, reg_CODE
) + lr_code_offset
;
3810 #ifdef ARCH_HAS_NPC_REGISTER
3811 if (from_space_p(*os_context_npc_addr(context
)))
3812 *os_context_npc_addr(context
) = *os_context_register_addr(context
, reg_CODE
) + npc_code_offset
;
3813 #endif /* ARCH_HAS_NPC_REGISTER */
3817 scavenge_interrupt_contexts(void)
3820 os_context_t
*context
;
3822 struct thread
*th
=arch_os_get_current_thread();
3824 index
= fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX
,0));
3826 #if defined(DEBUG_PRINT_CONTEXT_INDEX)
3827 printf("Number of active contexts: %d\n", index
);
3830 for (i
= 0; i
< index
; i
++) {
3831 context
= th
->interrupt_contexts
[i
];
3832 scavenge_interrupt_context(context
);
3838 #if defined(LISP_FEATURE_SB_THREAD)
3840 preserve_context_registers (os_context_t
*c
)
3843 /* On Darwin the signal context isn't a contiguous block of memory,
3844 * so just preserve_pointering its contents won't be sufficient.
3846 #if defined(LISP_FEATURE_DARWIN)
3847 #if defined LISP_FEATURE_X86
3848 preserve_pointer((void*)*os_context_register_addr(c
,reg_EAX
));
3849 preserve_pointer((void*)*os_context_register_addr(c
,reg_ECX
));
3850 preserve_pointer((void*)*os_context_register_addr(c
,reg_EDX
));
3851 preserve_pointer((void*)*os_context_register_addr(c
,reg_EBX
));
3852 preserve_pointer((void*)*os_context_register_addr(c
,reg_ESI
));
3853 preserve_pointer((void*)*os_context_register_addr(c
,reg_EDI
));
3854 preserve_pointer((void*)*os_context_pc_addr(c
));
3855 #elif defined LISP_FEATURE_X86_64
3856 preserve_pointer((void*)*os_context_register_addr(c
,reg_RAX
));
3857 preserve_pointer((void*)*os_context_register_addr(c
,reg_RCX
));
3858 preserve_pointer((void*)*os_context_register_addr(c
,reg_RDX
));
3859 preserve_pointer((void*)*os_context_register_addr(c
,reg_RBX
));
3860 preserve_pointer((void*)*os_context_register_addr(c
,reg_RSI
));
3861 preserve_pointer((void*)*os_context_register_addr(c
,reg_RDI
));
3862 preserve_pointer((void*)*os_context_register_addr(c
,reg_R8
));
3863 preserve_pointer((void*)*os_context_register_addr(c
,reg_R9
));
3864 preserve_pointer((void*)*os_context_register_addr(c
,reg_R10
));
3865 preserve_pointer((void*)*os_context_register_addr(c
,reg_R11
));
3866 preserve_pointer((void*)*os_context_register_addr(c
,reg_R12
));
3867 preserve_pointer((void*)*os_context_register_addr(c
,reg_R13
));
3868 preserve_pointer((void*)*os_context_register_addr(c
,reg_R14
));
3869 preserve_pointer((void*)*os_context_register_addr(c
,reg_R15
));
3870 preserve_pointer((void*)*os_context_pc_addr(c
));
3872 #error "preserve_context_registers needs to be tweaked for non-x86 Darwin"
3875 for(ptr
= ((void **)(c
+1))-1; ptr
>=(void **)c
; ptr
--) {
3876 preserve_pointer(*ptr
);
3881 /* Garbage collect a generation. If raise is 0 then the remains of the
3882 * generation are not raised to the next generation. */
3884 garbage_collect_generation(generation_index_t generation
, int raise
)
3886 unsigned long bytes_freed
;
3888 unsigned long static_space_size
;
3889 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
3892 gc_assert(generation
<= HIGHEST_NORMAL_GENERATION
);
3894 /* The oldest generation can't be raised. */
3895 gc_assert((generation
!= HIGHEST_NORMAL_GENERATION
) || (raise
== 0));
3897 /* Check if weak hash tables were processed in the previous GC. */
3898 gc_assert(weak_hash_tables
== NULL
);
3900 /* Initialize the weak pointer list. */
3901 weak_pointers
= NULL
;
3903 #ifdef LUTEX_WIDETAG
3904 unmark_lutexes(generation
);
3907 /* When a generation is not being raised it is transported to a
3908 * temporary generation (NUM_GENERATIONS), and lowered when
3909 * done. Set up this new generation. There should be no pages
3910 * allocated to it yet. */
3912 gc_assert(generations
[SCRATCH_GENERATION
].bytes_allocated
== 0);
3915 /* Set the global src and dest. generations */
3916 from_space
= generation
;
3918 new_space
= generation
+1;
3920 new_space
= SCRATCH_GENERATION
;
3922 /* Change to a new space for allocation, resetting the alloc_start_page */
3923 gc_alloc_generation
= new_space
;
3924 generations
[new_space
].alloc_start_page
= 0;
3925 generations
[new_space
].alloc_unboxed_start_page
= 0;
3926 generations
[new_space
].alloc_large_start_page
= 0;
3927 generations
[new_space
].alloc_large_unboxed_start_page
= 0;
3929 /* Before any pointers are preserved, the dont_move flags on the
3930 * pages need to be cleared. */
3931 for (i
= 0; i
< last_free_page
; i
++)
3932 if(page_table
[i
].gen
==from_space
)
3933 page_table
[i
].dont_move
= 0;
3935 /* Un-write-protect the old-space pages. This is essential for the
3936 * promoted pages as they may contain pointers into the old-space
3937 * which need to be scavenged. It also helps avoid unnecessary page
3938 * faults as forwarding pointers are written into them. They need to
3939 * be un-protected anyway before unmapping later. */
3940 unprotect_oldspace();
3942 /* Scavenge the stacks' conservative roots. */
3944 /* there are potentially two stacks for each thread: the main
3945 * stack, which may contain Lisp pointers, and the alternate stack.
3946 * We don't ever run Lisp code on the altstack, but it may
3947 * host a sigcontext with lisp objects in it */
3949 /* what we need to do: (1) find the stack pointer for the main
3950 * stack; scavenge it (2) find the interrupt context on the
3951 * alternate stack that might contain lisp values, and scavenge
3954 /* we assume that none of the preceding applies to the thread that
3955 * initiates GC. If you ever call GC from inside an altstack
3956 * handler, you will lose. */
3958 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
3959 /* And if we're saving a core, there's no point in being conservative. */
3960 if (conservative_stack
) {
3961 for_each_thread(th
) {
3963 void **esp
=(void **)-1;
3964 #ifdef LISP_FEATURE_SB_THREAD
3966 if(th
==arch_os_get_current_thread()) {
3967 /* Somebody is going to burn in hell for this, but casting
3968 * it in two steps shuts gcc up about strict aliasing. */
3969 esp
= (void **)((void *)&raise
);
3972 free
=fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX
,th
));
3973 for(i
=free
-1;i
>=0;i
--) {
3974 os_context_t
*c
=th
->interrupt_contexts
[i
];
3975 esp1
= (void **) *os_context_register_addr(c
,reg_SP
);
3976 if (esp1
>=(void **)th
->control_stack_start
&&
3977 esp1
<(void **)th
->control_stack_end
) {
3978 if(esp1
<esp
) esp
=esp1
;
3979 preserve_context_registers(c
);
3984 esp
= (void **)((void *)&raise
);
3986 for (ptr
= ((void **)th
->control_stack_end
)-1; ptr
>= esp
; ptr
--) {
3987 preserve_pointer(*ptr
);
3994 if (gencgc_verbose
> 1) {
3995 long num_dont_move_pages
= count_dont_move_pages();
3997 "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
3998 num_dont_move_pages
,
3999 num_dont_move_pages
* PAGE_BYTES
);
4003 /* Scavenge all the rest of the roots. */
4005 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
4007 * If not x86, we need to scavenge the interrupt context(s) and the
4010 scavenge_interrupt_contexts();
4011 scavenge_control_stack();
4014 /* Scavenge the Lisp functions of the interrupt handlers, taking
4015 * care to avoid SIG_DFL and SIG_IGN. */
4016 for (i
= 0; i
< NSIG
; i
++) {
4017 union interrupt_handler handler
= interrupt_handlers
[i
];
4018 if (!ARE_SAME_HANDLER(handler
.c
, SIG_IGN
) &&
4019 !ARE_SAME_HANDLER(handler
.c
, SIG_DFL
)) {
4020 scavenge((lispobj
*)(interrupt_handlers
+ i
), 1);
4023 /* Scavenge the binding stacks. */
4026 for_each_thread(th
) {
4027 long len
= (lispobj
*)get_binding_stack_pointer(th
) -
4028 th
->binding_stack_start
;
4029 scavenge((lispobj
*) th
->binding_stack_start
,len
);
4030 #ifdef LISP_FEATURE_SB_THREAD
4031 /* do the tls as well */
4032 len
=fixnum_value(SymbolValue(FREE_TLS_INDEX
,0)) -
4033 (sizeof (struct thread
))/(sizeof (lispobj
));
4034 scavenge((lispobj
*) (th
+1),len
);
4039 /* The original CMU CL code had scavenge-read-only-space code
4040 * controlled by the Lisp-level variable
4041 * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
4042 * wasn't documented under what circumstances it was useful or
4043 * safe to turn it on, so it's been turned off in SBCL. If you
4044 * want/need this functionality, and can test and document it,
4045 * please submit a patch. */
4047 if (SymbolValue(SCAVENGE_READ_ONLY_SPACE
) != NIL
) {
4048 unsigned long read_only_space_size
=
4049 (lispobj
*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER
) -
4050 (lispobj
*)READ_ONLY_SPACE_START
;
4052 "/scavenge read only space: %d bytes\n",
4053 read_only_space_size
* sizeof(lispobj
)));
4054 scavenge( (lispobj
*) READ_ONLY_SPACE_START
, read_only_space_size
);
4058 /* Scavenge static space. */
4060 (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0) -
4061 (lispobj
*)STATIC_SPACE_START
;
4062 if (gencgc_verbose
> 1) {
4064 "/scavenge static space: %d bytes\n",
4065 static_space_size
* sizeof(lispobj
)));
4067 scavenge( (lispobj
*) STATIC_SPACE_START
, static_space_size
);
4069 /* All generations but the generation being GCed need to be
4070 * scavenged. The new_space generation needs special handling as
4071 * objects may be moved in - it is handled separately below. */
4072 scavenge_generations(generation
+1, PSEUDO_STATIC_GENERATION
);
4074 /* Finally scavenge the new_space generation. Keep going until no
4075 * more objects are moved into the new generation */
4076 scavenge_newspace_generation(new_space
);
4078 /* FIXME: I tried reenabling this check when debugging unrelated
4079 * GC weirdness ca. sbcl-0.6.12.45, and it failed immediately.
4080 * Since the current GC code seems to work well, I'm guessing that
4081 * this debugging code is just stale, but I haven't tried to
4082 * figure it out. It should be figured out and then either made to
4083 * work or just deleted. */
4084 #define RESCAN_CHECK 0
4086 /* As a check re-scavenge the newspace once; no new objects should
4089 long old_bytes_allocated
= bytes_allocated
;
4090 long bytes_allocated
;
4092 /* Start with a full scavenge. */
4093 scavenge_newspace_generation_one_scan(new_space
);
4095 /* Flush the current regions, updating the tables. */
4096 gc_alloc_update_all_page_tables();
4098 bytes_allocated
= bytes_allocated
- old_bytes_allocated
;
4100 if (bytes_allocated
!= 0) {
4101 lose("Rescan of new_space allocated %d more bytes.\n",
4107 scan_weak_hash_tables();
4108 scan_weak_pointers();
4110 /* Flush the current regions, updating the tables. */
4111 gc_alloc_update_all_page_tables();
4113 /* Free the pages in oldspace, but not those marked dont_move. */
4114 bytes_freed
= free_oldspace();
4116 /* If the GC is not raising the age then lower the generation back
4117 * to its normal generation number */
4119 for (i
= 0; i
< last_free_page
; i
++)
4120 if ((page_table
[i
].bytes_used
!= 0)
4121 && (page_table
[i
].gen
== SCRATCH_GENERATION
))
4122 page_table
[i
].gen
= generation
;
4123 gc_assert(generations
[generation
].bytes_allocated
== 0);
4124 generations
[generation
].bytes_allocated
=
4125 generations
[SCRATCH_GENERATION
].bytes_allocated
;
4126 generations
[SCRATCH_GENERATION
].bytes_allocated
= 0;
4129 /* Reset the alloc_start_page for generation. */
4130 generations
[generation
].alloc_start_page
= 0;
4131 generations
[generation
].alloc_unboxed_start_page
= 0;
4132 generations
[generation
].alloc_large_start_page
= 0;
4133 generations
[generation
].alloc_large_unboxed_start_page
= 0;
4135 if (generation
>= verify_gens
) {
4139 verify_dynamic_space();
4142 /* Set the new gc trigger for the GCed generation. */
4143 generations
[generation
].gc_trigger
=
4144 generations
[generation
].bytes_allocated
4145 + generations
[generation
].bytes_consed_between_gc
;
4148 generations
[generation
].num_gc
= 0;
4150 ++generations
[generation
].num_gc
;
4152 #ifdef LUTEX_WIDETAG
4153 reap_lutexes(generation
);
4155 move_lutexes(generation
, generation
+1);
4159 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
4161 update_dynamic_space_free_pointer(void)
4163 page_index_t last_page
= -1, i
;
4165 for (i
= 0; i
< last_free_page
; i
++)
4166 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
4167 && (page_table
[i
].bytes_used
!= 0))
4170 last_free_page
= last_page
+1;
4172 set_alloc_pointer((lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
));
4173 return 0; /* dummy value: return something ... */
4177 remap_free_pages (page_index_t from
, page_index_t to
)
4179 page_index_t first_page
, last_page
;
4181 for (first_page
= from
; first_page
<= to
; first_page
++) {
4182 if (page_table
[first_page
].allocated
!= FREE_PAGE_FLAG
||
4183 page_table
[first_page
].need_to_zero
== 0) {
4187 last_page
= first_page
+ 1;
4188 while (page_table
[last_page
].allocated
== FREE_PAGE_FLAG
&&
4190 page_table
[last_page
].need_to_zero
== 1) {
4194 /* There's a mysterious Solaris/x86 problem with using mmap
4195 * tricks for memory zeroing. See sbcl-devel thread
4196 * "Re: patch: standalone executable redux".
4198 #if defined(LISP_FEATURE_SUNOS)
4199 zero_pages(first_page
, last_page
-1);
4201 zero_pages_with_mmap(first_page
, last_page
-1);
4204 first_page
= last_page
;
4208 generation_index_t small_generation_limit
= 1;
4210 /* GC all generations newer than last_gen, raising the objects in each
4211 * to the next older generation - we finish when all generations below
4212 * last_gen are empty. Then if last_gen is due for a GC, or if
4213 * last_gen==NUM_GENERATIONS (the scratch generation? eh?) we GC that
4214 * too. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
4216 * We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
4217 * last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
4219 collect_garbage(generation_index_t last_gen
)
4221 generation_index_t gen
= 0, i
;
4224 /* The largest value of last_free_page seen since the time
4225 * remap_free_pages was called. */
4226 static page_index_t high_water_mark
= 0;
4228 FSHOW((stderr
, "/entering collect_garbage(%d)\n", last_gen
));
4232 if (last_gen
> HIGHEST_NORMAL_GENERATION
+1) {
4234 "/collect_garbage: last_gen = %d, doing a level 0 GC\n",
4239 /* Flush the alloc regions updating the tables. */
4240 gc_alloc_update_all_page_tables();
4242 /* Verify the new objects created by Lisp code. */
4243 if (pre_verify_gen_0
) {
4244 FSHOW((stderr
, "pre-checking generation 0\n"));
4245 verify_generation(0);
4248 if (gencgc_verbose
> 1)
4249 print_generation_stats(0);
4252 /* Collect the generation. */
4254 if (gen
>= gencgc_oldest_gen_to_gc
) {
4255 /* Never raise the oldest generation. */
4260 || (generations
[gen
].num_gc
>= generations
[gen
].trigger_age
);
4263 if (gencgc_verbose
> 1) {
4265 "starting GC of generation %d with raise=%d alloc=%d trig=%d GCs=%d\n",
4268 generations
[gen
].bytes_allocated
,
4269 generations
[gen
].gc_trigger
,
4270 generations
[gen
].num_gc
));
4273 /* If an older generation is being filled, then update its
4276 generations
[gen
+1].cum_sum_bytes_allocated
+=
4277 generations
[gen
+1].bytes_allocated
;
4280 garbage_collect_generation(gen
, raise
);
4282 /* Reset the memory age cum_sum. */
4283 generations
[gen
].cum_sum_bytes_allocated
= 0;
4285 if (gencgc_verbose
> 1) {
4286 FSHOW((stderr
, "GC of generation %d finished:\n", gen
));
4287 print_generation_stats(0);
4291 } while ((gen
<= gencgc_oldest_gen_to_gc
)
4292 && ((gen
< last_gen
)
4293 || ((gen
<= gencgc_oldest_gen_to_gc
)
4295 && (generations
[gen
].bytes_allocated
4296 > generations
[gen
].gc_trigger
)
4297 && (gen_av_mem_age(gen
)
4298 > generations
[gen
].min_av_mem_age
))));
4300 /* Now if gen-1 was raised all generations before gen are empty.
4301 * If it wasn't raised then all generations before gen-1 are empty.
4303 * Now objects within this gen's pages cannot point to younger
4304 * generations unless they are written to. This can be exploited
4305 * by write-protecting the pages of gen; then when younger
4306 * generations are GCed only the pages which have been written
4311 gen_to_wp
= gen
- 1;
4313 /* There's not much point in WPing pages in generation 0 as it is
4314 * never scavenged (except promoted pages). */
4315 if ((gen_to_wp
> 0) && enable_page_protection
) {
4316 /* Check that they are all empty. */
4317 for (i
= 0; i
< gen_to_wp
; i
++) {
4318 if (generations
[i
].bytes_allocated
)
4319 lose("trying to write-protect gen. %d when gen. %d nonempty\n",
4322 write_protect_generation_pages(gen_to_wp
);
4325 /* Set gc_alloc() back to generation 0. The current regions should
4326 * be flushed after the above GCs. */
4327 gc_assert((boxed_region
.free_pointer
- boxed_region
.start_addr
) == 0);
4328 gc_alloc_generation
= 0;
4330 /* Save the high-water mark before updating last_free_page */
4331 if (last_free_page
> high_water_mark
)
4332 high_water_mark
= last_free_page
;
4334 update_dynamic_space_free_pointer();
4336 auto_gc_trigger
= bytes_allocated
+ bytes_consed_between_gcs
;
4338 fprintf(stderr
,"Next gc when %ld bytes have been consed\n",
4341 /* If we did a big GC (arbitrarily defined as gen > 1), release memory
4344 if (gen
> small_generation_limit
) {
4345 if (last_free_page
> high_water_mark
)
4346 high_water_mark
= last_free_page
;
4347 remap_free_pages(0, high_water_mark
);
4348 high_water_mark
= 0;
4353 SHOW("returning from collect_garbage");
4356 /* This is called by Lisp PURIFY when it is finished. All live objects
4357 * will have been moved to the RO and Static heaps. The dynamic space
4358 * will need a full re-initialization. We don't bother having Lisp
4359 * PURIFY flush the current gc_alloc() region, as the page_tables are
4360 * re-initialized, and every page is zeroed to be sure. */
4366 if (gencgc_verbose
> 1)
4367 SHOW("entering gc_free_heap");
4369 for (page
= 0; page
< page_table_pages
; page
++) {
4370 /* Skip free pages which should already be zero filled. */
4371 if (page_table
[page
].allocated
!= FREE_PAGE_FLAG
) {
4372 void *page_start
, *addr
;
4374 /* Mark the page free. The other slots are assumed invalid
4375 * when it is a FREE_PAGE_FLAG and bytes_used is 0 and it
4376 * should not be write-protected -- except that the
4377 * generation is used for the current region but it sets
4379 page_table
[page
].allocated
= FREE_PAGE_FLAG
;
4380 page_table
[page
].bytes_used
= 0;
4382 #ifndef LISP_FEATURE_WIN32 /* Pages already zeroed on win32? Not sure about this change. */
4383 /* Zero the page. */
4384 page_start
= (void *)page_address(page
);
4386 /* First, remove any write-protection. */
4387 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
4388 page_table
[page
].write_protected
= 0;
4390 os_invalidate(page_start
,PAGE_BYTES
);
4391 addr
= os_validate(page_start
,PAGE_BYTES
);
4392 if (addr
== NULL
|| addr
!= page_start
) {
4393 lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x\n",
4398 page_table
[page
].write_protected
= 0;
4400 } else if (gencgc_zero_check_during_free_heap
) {
4401 /* Double-check that the page is zero filled. */
4404 gc_assert(page_table
[page
].allocated
== FREE_PAGE_FLAG
);
4405 gc_assert(page_table
[page
].bytes_used
== 0);
4406 page_start
= (long *)page_address(page
);
4407 for (i
=0; i
<1024; i
++) {
4408 if (page_start
[i
] != 0) {
4409 lose("free region not zero at %x\n", page_start
+ i
);
4415 bytes_allocated
= 0;
4417 /* Initialize the generations. */
4418 for (page
= 0; page
< NUM_GENERATIONS
; page
++) {
4419 generations
[page
].alloc_start_page
= 0;
4420 generations
[page
].alloc_unboxed_start_page
= 0;
4421 generations
[page
].alloc_large_start_page
= 0;
4422 generations
[page
].alloc_large_unboxed_start_page
= 0;
4423 generations
[page
].bytes_allocated
= 0;
4424 generations
[page
].gc_trigger
= 2000000;
4425 generations
[page
].num_gc
= 0;
4426 generations
[page
].cum_sum_bytes_allocated
= 0;
4427 generations
[page
].lutexes
= NULL
;
4430 if (gencgc_verbose
> 1)
4431 print_generation_stats(0);
4433 /* Initialize gc_alloc(). */
4434 gc_alloc_generation
= 0;
4436 gc_set_region_empty(&boxed_region
);
4437 gc_set_region_empty(&unboxed_region
);
4440 set_alloc_pointer((lispobj
)((char *)heap_base
));
4442 if (verify_after_free_heap
) {
4443 /* Check whether purify has left any bad pointers. */
4445 SHOW("checking after free_heap\n");
4455 /* Compute the number of pages needed for the dynamic space.
4456 * Dynamic space size should be aligned on page size. */
4457 page_table_pages
= dynamic_space_size
/PAGE_BYTES
;
4458 gc_assert(dynamic_space_size
== (size_t) page_table_pages
*PAGE_BYTES
);
4460 page_table
= calloc(page_table_pages
, sizeof(struct page
));
4461 gc_assert(page_table
);
4464 scavtab
[WEAK_POINTER_WIDETAG
] = scav_weak_pointer
;
4465 transother
[SIMPLE_ARRAY_WIDETAG
] = trans_boxed_large
;
4467 #ifdef LUTEX_WIDETAG
4468 scavtab
[LUTEX_WIDETAG
] = scav_lutex
;
4469 transother
[LUTEX_WIDETAG
] = trans_lutex
;
4470 sizetab
[LUTEX_WIDETAG
] = size_lutex
;
4473 heap_base
= (void*)DYNAMIC_SPACE_START
;
4475 /* Initialize each page structure. */
4476 for (i
= 0; i
< page_table_pages
; i
++) {
4477 /* Initialize all pages as free. */
4478 page_table
[i
].allocated
= FREE_PAGE_FLAG
;
4479 page_table
[i
].bytes_used
= 0;
4481 /* Pages are not write-protected at startup. */
4482 page_table
[i
].write_protected
= 0;
4485 bytes_allocated
= 0;
4487 /* Initialize the generations.
4489 * FIXME: very similar to code in gc_free_heap(), should be shared */
4490 for (i
= 0; i
< NUM_GENERATIONS
; i
++) {
4491 generations
[i
].alloc_start_page
= 0;
4492 generations
[i
].alloc_unboxed_start_page
= 0;
4493 generations
[i
].alloc_large_start_page
= 0;
4494 generations
[i
].alloc_large_unboxed_start_page
= 0;
4495 generations
[i
].bytes_allocated
= 0;
4496 generations
[i
].gc_trigger
= 2000000;
4497 generations
[i
].num_gc
= 0;
4498 generations
[i
].cum_sum_bytes_allocated
= 0;
4499 /* the tune-able parameters */
4500 generations
[i
].bytes_consed_between_gc
= 2000000;
4501 generations
[i
].trigger_age
= 1;
4502 generations
[i
].min_av_mem_age
= 0.75;
4503 generations
[i
].lutexes
= NULL
;
4506 /* Initialize gc_alloc. */
4507 gc_alloc_generation
= 0;
4508 gc_set_region_empty(&boxed_region
);
4509 gc_set_region_empty(&unboxed_region
);
4514 /* Pick up the dynamic space from after a core load.
4516 * The ALLOCATION_POINTER points to the end of the dynamic space.
4520 gencgc_pickup_dynamic(void)
4522 page_index_t page
= 0;
4523 long alloc_ptr
= get_alloc_pointer();
4524 lispobj
*prev
=(lispobj
*)page_address(page
);
4525 generation_index_t gen
= PSEUDO_STATIC_GENERATION
;
4528 lispobj
*first
,*ptr
= (lispobj
*)page_address(page
);
4529 page_table
[page
].allocated
= BOXED_PAGE_FLAG
;
4530 page_table
[page
].gen
= gen
;
4531 page_table
[page
].bytes_used
= PAGE_BYTES
;
4532 page_table
[page
].large_object
= 0;
4533 page_table
[page
].write_protected
= 0;
4534 page_table
[page
].write_protected_cleared
= 0;
4535 page_table
[page
].dont_move
= 0;
4536 page_table
[page
].need_to_zero
= 1;
4538 if (!gencgc_partial_pickup
) {
4539 first
=gc_search_space(prev
,(ptr
+2)-prev
,ptr
);
4540 if(ptr
== first
) prev
=ptr
;
4541 page_table
[page
].first_object_offset
=
4542 (void *)prev
- page_address(page
);
4545 } while ((long)page_address(page
) < alloc_ptr
);
4547 #ifdef LUTEX_WIDETAG
4548 /* Lutexes have been registered in generation 0 by coreparse, and
4549 * need to be moved to the right one manually.
4551 move_lutexes(0, PSEUDO_STATIC_GENERATION
);
4554 last_free_page
= page
;
4556 generations
[gen
].bytes_allocated
= PAGE_BYTES
*page
;
4557 bytes_allocated
= PAGE_BYTES
*page
;
4559 gc_alloc_update_all_page_tables();
4560 write_protect_generation_pages(gen
);
4564 gc_initialize_pointers(void)
4566 gencgc_pickup_dynamic();
4572 /* alloc(..) is the external interface for memory allocation. It
4573 * allocates to generation 0. It is not called from within the garbage
4574 * collector as it is only external uses that need the check for heap
4575 * size (GC trigger) and to disable the interrupts (interrupts are
4576 * always disabled during a GC).
4578 * The vops that call alloc(..) assume that the returned space is zero-filled.
4579 * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
4581 * The check for a GC trigger is only performed when the current
4582 * region is full, so in most cases it's not needed. */
4587 struct thread
*thread
=arch_os_get_current_thread();
4588 struct alloc_region
*region
=
4589 #ifdef LISP_FEATURE_SB_THREAD
4590 thread
? &(thread
->alloc_region
) : &boxed_region
;
4594 #ifndef LISP_FEATURE_WIN32
4595 lispobj alloc_signal
;
4598 void *new_free_pointer
;
4600 gc_assert(nbytes
>0);
4602 /* Check for alignment allocation problems. */
4603 gc_assert((((unsigned long)region
->free_pointer
& LOWTAG_MASK
) == 0)
4604 && ((nbytes
& LOWTAG_MASK
) == 0));
4608 /* there are a few places in the C code that allocate data in the
4609 * heap before Lisp starts. This is before interrupts are enabled,
4610 * so we don't need to check for pseudo-atomic */
4611 #ifdef LISP_FEATURE_SB_THREAD
4612 if(!get_psuedo_atomic_atomic(th
)) {
4614 fprintf(stderr
, "fatal error in thread 0x%x, tid=%ld\n",
4616 __asm__("movl %fs,%0" : "=r" (fs
) : );
4617 fprintf(stderr
, "fs is %x, th->tls_cookie=%x \n",
4618 debug_get_fs(),th
->tls_cookie
);
4619 lose("If you see this message before 2004.01.31, mail details to sbcl-devel\n");
4622 gc_assert(get_pseudo_atomic_atomic(th
));
4626 /* maybe we can do this quickly ... */
4627 new_free_pointer
= region
->free_pointer
+ nbytes
;
4628 if (new_free_pointer
<= region
->end_addr
) {
4629 new_obj
= (void*)(region
->free_pointer
);
4630 region
->free_pointer
= new_free_pointer
;
4631 return(new_obj
); /* yup */
4634 /* we have to go the long way around, it seems. Check whether
4635 * we should GC in the near future
4637 if (auto_gc_trigger
&& bytes_allocated
> auto_gc_trigger
) {
4638 gc_assert(get_pseudo_atomic_atomic(thread
));
4639 /* Don't flood the system with interrupts if the need to gc is
4640 * already noted. This can happen for example when SUB-GC
4641 * allocates or after a gc triggered in a WITHOUT-GCING. */
4642 if (SymbolValue(GC_PENDING
,thread
) == NIL
) {
4643 /* set things up so that GC happens when we finish the PA
4645 SetSymbolValue(GC_PENDING
,T
,thread
);
4646 if (SymbolValue(GC_INHIBIT
,thread
) == NIL
)
4647 set_pseudo_atomic_interrupted(thread
);
4650 new_obj
= gc_alloc_with_region(nbytes
,0,region
,0);
4652 #ifndef LISP_FEATURE_WIN32
4653 alloc_signal
= SymbolValue(ALLOC_SIGNAL
,thread
);
4654 if ((alloc_signal
& FIXNUM_TAG_MASK
) == 0) {
4655 if ((signed long) alloc_signal
<= 0) {
4656 #ifdef LISP_FEATURE_SB_THREAD
4657 kill_thread_safely(thread
->os_thread
, SIGPROF
);
4662 SetSymbolValue(ALLOC_SIGNAL
,
4663 alloc_signal
- (1 << N_FIXNUM_TAG_BITS
),
4673 * shared support for the OS-dependent signal handlers which
4674 * catch GENCGC-related write-protect violations
4677 void unhandled_sigmemoryfault(void* addr
);
4679 /* Depending on which OS we're running under, different signals might
4680 * be raised for a violation of write protection in the heap. This
4681 * function factors out the common generational GC magic which needs
4682 * to invoked in this case, and should be called from whatever signal
4683 * handler is appropriate for the OS we're running under.
4685 * Return true if this signal is a normal generational GC thing that
4686 * we were able to handle, or false if it was abnormal and control
4687 * should fall through to the general SIGSEGV/SIGBUS/whatever logic. */
4690 gencgc_handle_wp_violation(void* fault_addr
)
4692 page_index_t page_index
= find_page_index(fault_addr
);
4694 #ifdef QSHOW_SIGNALS
4695 FSHOW((stderr
, "heap WP violation? fault_addr=%x, page_index=%d\n",
4696 fault_addr
, page_index
));
4699 /* Check whether the fault is within the dynamic space. */
4700 if (page_index
== (-1)) {
4702 /* It can be helpful to be able to put a breakpoint on this
4703 * case to help diagnose low-level problems. */
4704 unhandled_sigmemoryfault(fault_addr
);
4706 /* not within the dynamic space -- not our responsibility */
4710 if (page_table
[page_index
].write_protected
) {
4711 /* Unprotect the page. */
4712 os_protect(page_address(page_index
), PAGE_BYTES
, OS_VM_PROT_ALL
);
4713 page_table
[page_index
].write_protected_cleared
= 1;
4714 page_table
[page_index
].write_protected
= 0;
4716 /* The only acceptable reason for this signal on a heap
4717 * access is that GENCGC write-protected the page.
4718 * However, if two CPUs hit a wp page near-simultaneously,
4719 * we had better not have the second one lose here if it
4720 * does this test after the first one has already set wp=0
4722 if(page_table
[page_index
].write_protected_cleared
!= 1)
4723 lose("fault in heap page %d not marked as write-protected\nboxed_region.first_page: %d, boxed_region.last_page %d\n",
4724 page_index
, boxed_region
.first_page
, boxed_region
.last_page
);
4726 /* Don't worry, we can handle it. */
4730 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
4731 * it's not just a case of the program hitting the write barrier, and
4732 * are about to let Lisp deal with it. It's basically just a
4733 * convenient place to set a gdb breakpoint. */
4735 unhandled_sigmemoryfault(void *addr
)
4738 void gc_alloc_update_all_page_tables(void)
4740 /* Flush the alloc regions updating the tables. */
4743 gc_alloc_update_page_tables(0, &th
->alloc_region
);
4744 gc_alloc_update_page_tables(1, &unboxed_region
);
4745 gc_alloc_update_page_tables(0, &boxed_region
);
4749 gc_set_region_empty(struct alloc_region
*region
)
4751 region
->first_page
= 0;
4752 region
->last_page
= -1;
4753 region
->start_addr
= page_address(0);
4754 region
->free_pointer
= page_address(0);
4755 region
->end_addr
= page_address(0);
4759 zero_all_free_pages()
4763 for (i
= 0; i
< last_free_page
; i
++) {
4764 if (page_table
[i
].allocated
== FREE_PAGE_FLAG
) {
4765 #ifdef READ_PROTECT_FREE_PAGES
4766 os_protect(page_address(i
),
4775 /* Things to do before doing a final GC before saving a core (without
4778 * + Pages in large_object pages aren't moved by the GC, so we need to
4779 * unset that flag from all pages.
4780 * + The pseudo-static generation isn't normally collected, but it seems
4781 * reasonable to collect it at least when saving a core. So move the
4782 * pages to a normal generation.
4785 prepare_for_final_gc ()
4788 for (i
= 0; i
< last_free_page
; i
++) {
4789 page_table
[i
].large_object
= 0;
4790 if (page_table
[i
].gen
== PSEUDO_STATIC_GENERATION
) {
4791 int used
= page_table
[i
].bytes_used
;
4792 page_table
[i
].gen
= HIGHEST_NORMAL_GENERATION
;
4793 generations
[PSEUDO_STATIC_GENERATION
].bytes_allocated
-= used
;
4794 generations
[HIGHEST_NORMAL_GENERATION
].bytes_allocated
+= used
;
4800 /* Do a non-conservative GC, and then save a core with the initial
4801 * function being set to the value of the static symbol
4802 * SB!VM:RESTART-LISP-FUNCTION */
4804 gc_and_save(char *filename
, int prepend_runtime
)
4807 void *runtime_bytes
= NULL
;
4808 size_t runtime_size
;
4810 file
= prepare_to_save(filename
, prepend_runtime
, &runtime_bytes
,
4815 conservative_stack
= 0;
4817 /* The filename might come from Lisp, and be moved by the now
4818 * non-conservative GC. */
4819 filename
= strdup(filename
);
4821 /* Collect twice: once into relatively high memory, and then back
4822 * into low memory. This compacts the retained data into the lower
4823 * pages, minimizing the size of the core file.
4825 prepare_for_final_gc();
4826 gencgc_alloc_start_page
= last_free_page
;
4827 collect_garbage(HIGHEST_NORMAL_GENERATION
+1);
4829 prepare_for_final_gc();
4830 gencgc_alloc_start_page
= -1;
4831 collect_garbage(HIGHEST_NORMAL_GENERATION
+1);
4833 if (prepend_runtime
)
4834 save_runtime_to_filehandle(file
, runtime_bytes
, runtime_size
);
4836 /* The dumper doesn't know that pages need to be zeroed before use. */
4837 zero_all_free_pages();
4838 save_to_filehandle(file
, filename
, SymbolValue(RESTART_LISP_FUNCTION
,0),
4840 /* Oops. Save still managed to fail. Since we've mangled the stack
4841 * beyond hope, there's not much we can do.
4842 * (beyond FUNCALLing RESTART_LISP_FUNCTION, but I suspect that's
4843 * going to be rather unsatisfactory too... */
4844 lose("Attempt to save core after non-conservative GC failed.\n");