2 * GENerational Conservative Garbage Collector for SBCL x86
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>.
36 #include "interrupt.h"
42 #include "gc-internal.h"
44 #include "genesis/vector.h"
45 #include "genesis/weak-pointer.h"
46 #include "genesis/simple-fun.h"
48 /* forward declarations */
49 long gc_find_freeish_pages(long *restart_page_ptr
, long nbytes
, int unboxed
);
50 static void gencgc_pickup_dynamic(void);
57 /* the number of actual generations. (The number of 'struct
58 * generation' objects is one more than this, because one object
59 * serves as scratch when GC'ing.) */
60 #define NUM_GENERATIONS 6
62 /* Should we use page protection to help avoid the scavenging of pages
63 * that don't have pointers to younger generations? */
64 boolean enable_page_protection
= 1;
66 /* Should we unmap a page and re-mmap it to have it zero filled? */
67 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
68 /* comment from cmucl-2.4.8: This can waste a lot of swap on FreeBSD
69 * so don't unmap there.
71 * The CMU CL comment didn't specify a version, but was probably an
72 * old version of FreeBSD (pre-4.0), so this might no longer be true.
73 * OTOH, if it is true, this behavior might exist on OpenBSD too, so
74 * for now we don't unmap there either. -- WHN 2001-04-07 */
75 boolean gencgc_unmap_zero
= 0;
77 boolean gencgc_unmap_zero
= 1;
80 /* the minimum size (in bytes) for a large object*/
81 unsigned large_object_size
= 4 * PAGE_BYTES
;
90 /* the verbosity level. All non-error messages are disabled at level 0;
91 * and only a few rare messages are printed at level 1. */
93 unsigned gencgc_verbose
= 1;
95 unsigned gencgc_verbose
= 0;
98 /* FIXME: At some point enable the various error-checking things below
99 * and see what they say. */
101 /* We hunt for pointers to old-space, when GCing generations >= verify_gen.
102 * Set verify_gens to NUM_GENERATIONS to disable this kind of check. */
103 int verify_gens
= NUM_GENERATIONS
;
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;
130 * GC structures and variables
133 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
134 unsigned long bytes_allocated
= 0;
135 extern unsigned long bytes_consed_between_gcs
; /* gc-common.c */
136 unsigned long auto_gc_trigger
= 0;
138 /* the source and destination generations. These are set before a GC starts
144 /* An array of page structures is statically allocated.
145 * This helps quickly map between an address its page structure.
146 * NUM_PAGES is set from the size of the dynamic space. */
147 struct page page_table
[NUM_PAGES
];
149 /* To map addresses to page structures the address of the first page
151 static void *heap_base
= NULL
;
153 #if N_WORD_BITS == 32
154 #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
155 #elif N_WORD_BITS == 64
156 #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
159 /* Calculate the start address for the given page number. */
161 page_address(long page_num
)
163 return (heap_base
+ (page_num
* PAGE_BYTES
));
166 /* Find the page index within the page_table for the given
167 * address. Return -1 on failure. */
169 find_page_index(void *addr
)
171 long index
= addr
-heap_base
;
174 index
= ((unsigned long)index
)/PAGE_BYTES
;
175 if (index
< NUM_PAGES
)
182 /* a structure to hold the state of a generation */
185 /* the first page that gc_alloc() checks on its next call */
186 long alloc_start_page
;
188 /* the first page that gc_alloc_unboxed() checks on its next call */
189 long alloc_unboxed_start_page
;
191 /* the first page that gc_alloc_large (boxed) considers on its next
192 * call. (Although it always allocates after the boxed_region.) */
193 long alloc_large_start_page
;
195 /* the first page that gc_alloc_large (unboxed) considers on its
196 * next call. (Although it always allocates after the
197 * current_unboxed_region.) */
198 long alloc_large_unboxed_start_page
;
200 /* the bytes allocated to this generation */
201 long bytes_allocated
;
203 /* the number of bytes at which to trigger a GC */
206 /* to calculate a new level for gc_trigger */
207 long bytes_consed_between_gc
;
209 /* the number of GCs since the last raise */
212 /* the average age after which a GC will raise objects to the
216 /* the cumulative sum of the bytes allocated to this generation. It is
217 * cleared after a GC on this generations, and update before new
218 * objects are added from a GC of a younger generation. Dividing by
219 * the bytes_allocated will give the average age of the memory in
220 * this generation since its last GC. */
221 long cum_sum_bytes_allocated
;
223 /* a minimum average memory age before a GC will occur helps
224 * prevent a GC when a large number of new live objects have been
225 * added, in which case a GC could be a waste of time */
226 double min_av_mem_age
;
228 /* the number of actual generations. (The number of 'struct
229 * generation' objects is one more than this, because one object
230 * serves as scratch when GC'ing.) */
231 #define NUM_GENERATIONS 6
233 /* an array of generation structures. There needs to be one more
234 * generation structure than actual generations as the oldest
235 * generation is temporarily raised then lowered. */
236 struct generation generations
[NUM_GENERATIONS
+1];
238 /* the oldest generation that is will currently be GCed by default.
239 * Valid values are: 0, 1, ... (NUM_GENERATIONS-1)
241 * The default of (NUM_GENERATIONS-1) enables GC on all generations.
243 * Setting this to 0 effectively disables the generational nature of
244 * the GC. In some applications generational GC may not be useful
245 * because there are no long-lived objects.
247 * An intermediate value could be handy after moving long-lived data
248 * into an older generation so an unnecessary GC of this long-lived
249 * data can be avoided. */
250 unsigned int gencgc_oldest_gen_to_gc
= NUM_GENERATIONS
-1;
252 /* The maximum free page in the heap is maintained and used to update
253 * ALLOCATION_POINTER which is used by the room function to limit its
254 * search of the heap. XX Gencgc obviously needs to be better
255 * integrated with the Lisp code. */
256 static long last_free_page
;
258 /* This lock is to prevent multiple threads from simultaneously
259 * allocating new regions which overlap each other. Note that the
260 * majority of GC is single-threaded, but alloc() may be called from
261 * >1 thread at a time and must be thread-safe. This lock must be
262 * seized before all accesses to generations[] or to parts of
263 * page_table[] that other threads may want to see */
265 static lispobj free_pages_lock
=0;
269 * miscellaneous heap functions
272 /* Count the number of pages which are write-protected within the
273 * given generation. */
275 count_write_protect_generation_pages(int generation
)
280 for (i
= 0; i
< last_free_page
; i
++)
281 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
282 && (page_table
[i
].gen
== generation
)
283 && (page_table
[i
].write_protected
== 1))
288 /* Count the number of pages within the given generation. */
290 count_generation_pages(int generation
)
295 for (i
= 0; i
< last_free_page
; i
++)
296 if ((page_table
[i
].allocated
!= 0)
297 && (page_table
[i
].gen
== generation
))
304 count_dont_move_pages(void)
308 for (i
= 0; i
< last_free_page
; i
++) {
309 if ((page_table
[i
].allocated
!= 0) && (page_table
[i
].dont_move
!= 0)) {
317 /* Work through the pages and add up the number of bytes used for the
318 * given generation. */
320 count_generation_bytes_allocated (int gen
)
324 for (i
= 0; i
< last_free_page
; i
++) {
325 if ((page_table
[i
].allocated
!= 0) && (page_table
[i
].gen
== gen
))
326 result
+= page_table
[i
].bytes_used
;
331 /* Return the average age of the memory in a generation. */
333 gen_av_mem_age(int gen
)
335 if (generations
[gen
].bytes_allocated
== 0)
339 ((double)generations
[gen
].cum_sum_bytes_allocated
)
340 / ((double)generations
[gen
].bytes_allocated
);
343 void fpu_save(int *); /* defined in x86-assem.S */
344 void fpu_restore(int *); /* defined in x86-assem.S */
345 /* The verbose argument controls how much to print: 0 for normal
346 * level of detail; 1 for debugging. */
348 print_generation_stats(int verbose
) /* FIXME: should take FILE argument */
353 /* This code uses the FP instructions which may be set up for Lisp
354 * so they need to be saved and reset for C. */
357 /* number of generations to print */
359 gens
= NUM_GENERATIONS
+1;
361 gens
= NUM_GENERATIONS
;
363 /* Print the heap stats. */
365 " Gen Boxed Unboxed LB LUB !move Alloc Waste Trig WP GCs Mem-age\n");
367 for (i
= 0; i
< gens
; i
++) {
371 int large_boxed_cnt
= 0;
372 int large_unboxed_cnt
= 0;
375 for (j
= 0; j
< last_free_page
; j
++)
376 if (page_table
[j
].gen
== i
) {
378 /* Count the number of boxed pages within the given
380 if (page_table
[j
].allocated
& BOXED_PAGE_FLAG
) {
381 if (page_table
[j
].large_object
)
386 if(page_table
[j
].dont_move
) pinned_cnt
++;
387 /* Count the number of unboxed pages within the given
389 if (page_table
[j
].allocated
& UNBOXED_PAGE_FLAG
) {
390 if (page_table
[j
].large_object
)
397 gc_assert(generations
[i
].bytes_allocated
398 == count_generation_bytes_allocated(i
));
400 " %1d: %5d %5d %5d %5d %5d %8ld %5ld %8ld %4ld %3d %7.4f\n",
402 boxed_cnt
, unboxed_cnt
, large_boxed_cnt
, large_unboxed_cnt
,
404 generations
[i
].bytes_allocated
,
405 (count_generation_pages(i
)*PAGE_BYTES
406 - generations
[i
].bytes_allocated
),
407 generations
[i
].gc_trigger
,
408 count_write_protect_generation_pages(i
),
409 generations
[i
].num_gc
,
412 fprintf(stderr
," Total bytes allocated=%ld\n", bytes_allocated
);
414 fpu_restore(fpu_state
);
418 * allocation routines
422 * To support quick and inline allocation, regions of memory can be
423 * allocated and then allocated from with just a free pointer and a
424 * check against an end address.
426 * Since objects can be allocated to spaces with different properties
427 * e.g. boxed/unboxed, generation, ages; there may need to be many
428 * allocation regions.
430 * Each allocation region may be start within a partly used page. Many
431 * features of memory use are noted on a page wise basis, e.g. the
432 * generation; so if a region starts within an existing allocated page
433 * it must be consistent with this page.
435 * During the scavenging of the newspace, objects will be transported
436 * into an allocation region, and pointers updated to point to this
437 * allocation region. It is possible that these pointers will be
438 * scavenged again before the allocation region is closed, e.g. due to
439 * trans_list which jumps all over the place to cleanup the list. It
440 * is important to be able to determine properties of all objects
441 * pointed to when scavenging, e.g to detect pointers to the oldspace.
442 * Thus it's important that the allocation regions have the correct
443 * properties set when allocated, and not just set when closed. The
444 * region allocation routines return regions with the specified
445 * properties, and grab all the pages, setting their properties
446 * appropriately, except that the amount used is not known.
448 * These regions are used to support quicker allocation using just a
449 * free pointer. The actual space used by the region is not reflected
450 * in the pages tables until it is closed. It can't be scavenged until
453 * When finished with the region it should be closed, which will
454 * update the page tables for the actual space used returning unused
455 * space. Further it may be noted in the new regions which is
456 * necessary when scavenging the newspace.
458 * Large objects may be allocated directly without an allocation
459 * region, the page tables are updated immediately.
461 * Unboxed objects don't contain pointers to other objects and so
462 * don't need scavenging. Further they can't contain pointers to
463 * younger generations so WP is not needed. By allocating pages to
464 * unboxed objects the whole page never needs scavenging or
465 * write-protecting. */
467 /* We are only using two regions at present. Both are for the current
468 * newspace generation. */
469 struct alloc_region boxed_region
;
470 struct alloc_region unboxed_region
;
472 /* The generation currently being allocated to. */
473 static int gc_alloc_generation
;
475 /* Find a new region with room for at least the given number of bytes.
477 * It starts looking at the current generation's alloc_start_page. So
478 * may pick up from the previous region if there is enough space. This
479 * keeps the allocation contiguous when scavenging the newspace.
481 * The alloc_region should have been closed by a call to
482 * gc_alloc_update_page_tables(), and will thus be in an empty state.
484 * To assist the scavenging functions write-protected pages are not
485 * used. Free pages should not be write-protected.
487 * It is critical to the conservative GC that the start of regions be
488 * known. To help achieve this only small regions are allocated at a
491 * During scavenging, pointers may be found to within the current
492 * region and the page generation must be set so that pointers to the
493 * from space can be recognized. Therefore the generation of pages in
494 * the region are set to gc_alloc_generation. To prevent another
495 * allocation call using the same pages, all the pages in the region
496 * are allocated, although they will initially be empty.
499 gc_alloc_new_region(long nbytes
, int unboxed
, struct alloc_region
*alloc_region
)
508 "/alloc_new_region for %d bytes from gen %d\n",
509 nbytes, gc_alloc_generation));
512 /* Check that the region is in a reset state. */
513 gc_assert((alloc_region
->first_page
== 0)
514 && (alloc_region
->last_page
== -1)
515 && (alloc_region
->free_pointer
== alloc_region
->end_addr
));
516 get_spinlock(&free_pages_lock
,(long) alloc_region
);
519 generations
[gc_alloc_generation
].alloc_unboxed_start_page
;
522 generations
[gc_alloc_generation
].alloc_start_page
;
524 last_page
=gc_find_freeish_pages(&first_page
,nbytes
,unboxed
);
525 bytes_found
=(PAGE_BYTES
- page_table
[first_page
].bytes_used
)
526 + PAGE_BYTES
*(last_page
-first_page
);
528 /* Set up the alloc_region. */
529 alloc_region
->first_page
= first_page
;
530 alloc_region
->last_page
= last_page
;
531 alloc_region
->start_addr
= page_table
[first_page
].bytes_used
532 + page_address(first_page
);
533 alloc_region
->free_pointer
= alloc_region
->start_addr
;
534 alloc_region
->end_addr
= alloc_region
->start_addr
+ bytes_found
;
536 /* Set up the pages. */
538 /* The first page may have already been in use. */
539 if (page_table
[first_page
].bytes_used
== 0) {
541 page_table
[first_page
].allocated
= UNBOXED_PAGE_FLAG
;
543 page_table
[first_page
].allocated
= BOXED_PAGE_FLAG
;
544 page_table
[first_page
].gen
= gc_alloc_generation
;
545 page_table
[first_page
].large_object
= 0;
546 page_table
[first_page
].first_object_offset
= 0;
550 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
552 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
553 page_table
[first_page
].allocated
|= OPEN_REGION_PAGE_FLAG
;
555 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
556 gc_assert(page_table
[first_page
].large_object
== 0);
558 for (i
= first_page
+1; i
<= last_page
; i
++) {
560 page_table
[i
].allocated
= UNBOXED_PAGE_FLAG
;
562 page_table
[i
].allocated
= BOXED_PAGE_FLAG
;
563 page_table
[i
].gen
= gc_alloc_generation
;
564 page_table
[i
].large_object
= 0;
565 /* This may not be necessary for unboxed regions (think it was
567 page_table
[i
].first_object_offset
=
568 alloc_region
->start_addr
- page_address(i
);
569 page_table
[i
].allocated
|= OPEN_REGION_PAGE_FLAG
;
571 /* Bump up last_free_page. */
572 if (last_page
+1 > last_free_page
) {
573 last_free_page
= last_page
+1;
574 SetSymbolValue(ALLOCATION_POINTER
,
575 (lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
),
578 release_spinlock(&free_pages_lock
);
580 /* we can do this after releasing free_pages_lock */
581 if (gencgc_zero_check
) {
583 for (p
= (long *)alloc_region
->start_addr
;
584 p
< (long *)alloc_region
->end_addr
; p
++) {
586 /* KLUDGE: It would be nice to use %lx and explicit casts
587 * (long) in code like this, so that it is less likely to
588 * break randomly when running on a machine with different
589 * word sizes. -- WHN 19991129 */
590 lose("The new region at %x is not zero.", p
);
597 /* If the record_new_objects flag is 2 then all new regions created
600 * If it's 1 then then it is only recorded if the first page of the
601 * current region is <= new_areas_ignore_page. This helps avoid
602 * unnecessary recording when doing full scavenge pass.
604 * The new_object structure holds the page, byte offset, and size of
605 * new regions of objects. Each new area is placed in the array of
606 * these structures pointer to by new_areas. new_areas_index holds the
607 * offset into new_areas.
609 * If new_area overflows NUM_NEW_AREAS then it stops adding them. The
610 * later code must detect this and handle it, probably by doing a full
611 * scavenge of a generation. */
612 #define NUM_NEW_AREAS 512
613 static int record_new_objects
= 0;
614 static long new_areas_ignore_page
;
620 static struct new_area (*new_areas
)[];
621 static long new_areas_index
;
624 /* Add a new area to new_areas. */
626 add_new_area(long first_page
, long offset
, long size
)
628 unsigned new_area_start
,c
;
631 /* Ignore if full. */
632 if (new_areas_index
>= NUM_NEW_AREAS
)
635 switch (record_new_objects
) {
639 if (first_page
> new_areas_ignore_page
)
648 new_area_start
= PAGE_BYTES
*first_page
+ offset
;
650 /* Search backwards for a prior area that this follows from. If
651 found this will save adding a new area. */
652 for (i
= new_areas_index
-1, c
= 0; (i
>= 0) && (c
< 8); i
--, c
++) {
654 PAGE_BYTES
*((*new_areas
)[i
].page
)
655 + (*new_areas
)[i
].offset
656 + (*new_areas
)[i
].size
;
658 "/add_new_area S1 %d %d %d %d\n",
659 i, c, new_area_start, area_end));*/
660 if (new_area_start
== area_end
) {
662 "/adding to [%d] %d %d %d with %d %d %d:\n",
664 (*new_areas)[i].page,
665 (*new_areas)[i].offset,
666 (*new_areas)[i].size,
670 (*new_areas
)[i
].size
+= size
;
675 (*new_areas
)[new_areas_index
].page
= first_page
;
676 (*new_areas
)[new_areas_index
].offset
= offset
;
677 (*new_areas
)[new_areas_index
].size
= size
;
679 "/new_area %d page %d offset %d size %d\n",
680 new_areas_index, first_page, offset, size));*/
683 /* Note the max new_areas used. */
684 if (new_areas_index
> max_new_areas
)
685 max_new_areas
= new_areas_index
;
688 /* Update the tables for the alloc_region. The region may be added to
691 * When done the alloc_region is set up so that the next quick alloc
692 * will fail safely and thus a new region will be allocated. Further
693 * it is safe to try to re-update the page table of this reset
696 gc_alloc_update_page_tables(int unboxed
, struct alloc_region
*alloc_region
)
702 long orig_first_page_bytes_used
;
707 first_page
= alloc_region
->first_page
;
709 /* Catch an unused alloc_region. */
710 if ((first_page
== 0) && (alloc_region
->last_page
== -1))
713 next_page
= first_page
+1;
715 get_spinlock(&free_pages_lock
,(long) alloc_region
);
716 if (alloc_region
->free_pointer
!= alloc_region
->start_addr
) {
717 /* some bytes were allocated in the region */
718 orig_first_page_bytes_used
= page_table
[first_page
].bytes_used
;
720 gc_assert(alloc_region
->start_addr
== (page_address(first_page
) + page_table
[first_page
].bytes_used
));
722 /* All the pages used need to be updated */
724 /* Update the first page. */
726 /* If the page was free then set up the gen, and
727 * first_object_offset. */
728 if (page_table
[first_page
].bytes_used
== 0)
729 gc_assert(page_table
[first_page
].first_object_offset
== 0);
730 page_table
[first_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
733 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
735 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
736 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
737 gc_assert(page_table
[first_page
].large_object
== 0);
741 /* Calculate the number of bytes used in this page. This is not
742 * always the number of new bytes, unless it was free. */
744 if ((bytes_used
= (alloc_region
->free_pointer
- page_address(first_page
)))>PAGE_BYTES
) {
745 bytes_used
= PAGE_BYTES
;
748 page_table
[first_page
].bytes_used
= bytes_used
;
749 byte_cnt
+= bytes_used
;
752 /* All the rest of the pages should be free. We need to set their
753 * first_object_offset pointer to the start of the region, and set
756 page_table
[next_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
758 gc_assert(page_table
[next_page
].allocated
==UNBOXED_PAGE_FLAG
);
760 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
761 gc_assert(page_table
[next_page
].bytes_used
== 0);
762 gc_assert(page_table
[next_page
].gen
== gc_alloc_generation
);
763 gc_assert(page_table
[next_page
].large_object
== 0);
765 gc_assert(page_table
[next_page
].first_object_offset
==
766 alloc_region
->start_addr
- page_address(next_page
));
768 /* Calculate the number of bytes used in this page. */
770 if ((bytes_used
= (alloc_region
->free_pointer
771 - page_address(next_page
)))>PAGE_BYTES
) {
772 bytes_used
= PAGE_BYTES
;
775 page_table
[next_page
].bytes_used
= bytes_used
;
776 byte_cnt
+= bytes_used
;
781 region_size
= alloc_region
->free_pointer
- alloc_region
->start_addr
;
782 bytes_allocated
+= region_size
;
783 generations
[gc_alloc_generation
].bytes_allocated
+= region_size
;
785 gc_assert((byte_cnt
- orig_first_page_bytes_used
) == region_size
);
787 /* Set the generations alloc restart page to the last page of
790 generations
[gc_alloc_generation
].alloc_unboxed_start_page
=
793 generations
[gc_alloc_generation
].alloc_start_page
= next_page
-1;
795 /* Add the region to the new_areas if requested. */
797 add_new_area(first_page
,orig_first_page_bytes_used
, region_size
);
801 "/gc_alloc_update_page_tables update %d bytes to gen %d\n",
803 gc_alloc_generation));
806 /* There are no bytes allocated. Unallocate the first_page if
807 * there are 0 bytes_used. */
808 page_table
[first_page
].allocated
&= ~(OPEN_REGION_PAGE_FLAG
);
809 if (page_table
[first_page
].bytes_used
== 0)
810 page_table
[first_page
].allocated
= FREE_PAGE_FLAG
;
813 /* Unallocate any unused pages. */
814 while (next_page
<= alloc_region
->last_page
) {
815 gc_assert(page_table
[next_page
].bytes_used
== 0);
816 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
819 release_spinlock(&free_pages_lock
);
820 /* alloc_region is per-thread, we're ok to do this unlocked */
821 gc_set_region_empty(alloc_region
);
824 static inline void *gc_quick_alloc(long nbytes
);
826 /* Allocate a possibly large object. */
828 gc_alloc_large(long nbytes
, int unboxed
, struct alloc_region
*alloc_region
)
832 long orig_first_page_bytes_used
;
838 get_spinlock(&free_pages_lock
,(long) alloc_region
);
842 generations
[gc_alloc_generation
].alloc_large_unboxed_start_page
;
844 first_page
= generations
[gc_alloc_generation
].alloc_large_start_page
;
846 if (first_page
<= alloc_region
->last_page
) {
847 first_page
= alloc_region
->last_page
+1;
850 last_page
=gc_find_freeish_pages(&first_page
,nbytes
,unboxed
);
852 gc_assert(first_page
> alloc_region
->last_page
);
854 generations
[gc_alloc_generation
].alloc_large_unboxed_start_page
=
857 generations
[gc_alloc_generation
].alloc_large_start_page
= last_page
;
859 /* Set up the pages. */
860 orig_first_page_bytes_used
= page_table
[first_page
].bytes_used
;
862 /* If the first page was free then set up the gen, and
863 * first_object_offset. */
864 if (page_table
[first_page
].bytes_used
== 0) {
866 page_table
[first_page
].allocated
= UNBOXED_PAGE_FLAG
;
868 page_table
[first_page
].allocated
= BOXED_PAGE_FLAG
;
869 page_table
[first_page
].gen
= gc_alloc_generation
;
870 page_table
[first_page
].first_object_offset
= 0;
871 page_table
[first_page
].large_object
= 1;
875 gc_assert(page_table
[first_page
].allocated
== UNBOXED_PAGE_FLAG
);
877 gc_assert(page_table
[first_page
].allocated
== BOXED_PAGE_FLAG
);
878 gc_assert(page_table
[first_page
].gen
== gc_alloc_generation
);
879 gc_assert(page_table
[first_page
].large_object
== 1);
883 /* Calc. the number of bytes used in this page. This is not
884 * always the number of new bytes, unless it was free. */
886 if ((bytes_used
= nbytes
+orig_first_page_bytes_used
) > PAGE_BYTES
) {
887 bytes_used
= PAGE_BYTES
;
890 page_table
[first_page
].bytes_used
= bytes_used
;
891 byte_cnt
+= bytes_used
;
893 next_page
= first_page
+1;
895 /* All the rest of the pages should be free. We need to set their
896 * first_object_offset pointer to the start of the region, and
897 * set the bytes_used. */
899 gc_assert(page_table
[next_page
].allocated
== FREE_PAGE_FLAG
);
900 gc_assert(page_table
[next_page
].bytes_used
== 0);
902 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
904 page_table
[next_page
].allocated
= BOXED_PAGE_FLAG
;
905 page_table
[next_page
].gen
= gc_alloc_generation
;
906 page_table
[next_page
].large_object
= 1;
908 page_table
[next_page
].first_object_offset
=
909 orig_first_page_bytes_used
- PAGE_BYTES
*(next_page
-first_page
);
911 /* Calculate the number of bytes used in this page. */
913 if ((bytes_used
=(nbytes
+orig_first_page_bytes_used
)-byte_cnt
) > PAGE_BYTES
) {
914 bytes_used
= PAGE_BYTES
;
917 page_table
[next_page
].bytes_used
= bytes_used
;
918 page_table
[next_page
].write_protected
=0;
919 page_table
[next_page
].dont_move
=0;
920 byte_cnt
+= bytes_used
;
924 gc_assert((byte_cnt
-orig_first_page_bytes_used
) == nbytes
);
926 bytes_allocated
+= nbytes
;
927 generations
[gc_alloc_generation
].bytes_allocated
+= nbytes
;
929 /* Add the region to the new_areas if requested. */
931 add_new_area(first_page
,orig_first_page_bytes_used
,nbytes
);
933 /* Bump up last_free_page */
934 if (last_page
+1 > last_free_page
) {
935 last_free_page
= last_page
+1;
936 SetSymbolValue(ALLOCATION_POINTER
,
937 (lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
),0);
939 release_spinlock(&free_pages_lock
);
941 return((void *)(page_address(first_page
)+orig_first_page_bytes_used
));
945 gc_find_freeish_pages(long *restart_page_ptr
, long nbytes
, int unboxed
)
950 long restart_page
=*restart_page_ptr
;
953 long large_p
=(nbytes
>=large_object_size
);
954 gc_assert(free_pages_lock
);
956 /* Search for a contiguous free space of at least nbytes. If it's
957 * a large object then align it on a page boundary by searching
958 * for a free page. */
961 first_page
= restart_page
;
963 while ((first_page
< NUM_PAGES
)
964 && (page_table
[first_page
].allocated
!= FREE_PAGE_FLAG
))
967 while (first_page
< NUM_PAGES
) {
968 if(page_table
[first_page
].allocated
== FREE_PAGE_FLAG
)
970 if((page_table
[first_page
].allocated
==
971 (unboxed
? UNBOXED_PAGE_FLAG
: BOXED_PAGE_FLAG
)) &&
972 (page_table
[first_page
].large_object
== 0) &&
973 (page_table
[first_page
].gen
== gc_alloc_generation
) &&
974 (page_table
[first_page
].bytes_used
< (PAGE_BYTES
-32)) &&
975 (page_table
[first_page
].write_protected
== 0) &&
976 (page_table
[first_page
].dont_move
== 0)) {
982 if (first_page
>= NUM_PAGES
) {
984 "Argh! gc_find_free_space failed (first_page), nbytes=%ld.\n",
986 print_generation_stats(1);
990 gc_assert(page_table
[first_page
].write_protected
== 0);
992 last_page
= first_page
;
993 bytes_found
= PAGE_BYTES
- page_table
[first_page
].bytes_used
;
995 while (((bytes_found
< nbytes
)
996 || (!large_p
&& (num_pages
< 2)))
997 && (last_page
< (NUM_PAGES
-1))
998 && (page_table
[last_page
+1].allocated
== FREE_PAGE_FLAG
)) {
1001 bytes_found
+= PAGE_BYTES
;
1002 gc_assert(page_table
[last_page
].write_protected
== 0);
1005 region_size
= (PAGE_BYTES
- page_table
[first_page
].bytes_used
)
1006 + PAGE_BYTES
*(last_page
-first_page
);
1008 gc_assert(bytes_found
== region_size
);
1009 restart_page
= last_page
+ 1;
1010 } while ((restart_page
< NUM_PAGES
) && (bytes_found
< nbytes
));
1012 /* Check for a failure */
1013 if ((restart_page
>= NUM_PAGES
) && (bytes_found
< nbytes
)) {
1015 "Argh! gc_find_freeish_pages failed (restart_page), nbytes=%ld.\n",
1017 print_generation_stats(1);
1020 *restart_page_ptr
=first_page
;
1024 /* Allocate bytes. All the rest of the special-purpose allocation
1025 * functions will eventually call this */
1028 gc_alloc_with_region(long nbytes
,int unboxed_p
, struct alloc_region
*my_region
,
1031 void *new_free_pointer
;
1033 if(nbytes
>=large_object_size
)
1034 return gc_alloc_large(nbytes
,unboxed_p
,my_region
);
1036 /* Check whether there is room in the current alloc region. */
1037 new_free_pointer
= my_region
->free_pointer
+ nbytes
;
1039 /* fprintf(stderr, "alloc %d bytes from %p to %p\n", nbytes,
1040 my_region->free_pointer, new_free_pointer); */
1042 if (new_free_pointer
<= my_region
->end_addr
) {
1043 /* If so then allocate from the current alloc region. */
1044 void *new_obj
= my_region
->free_pointer
;
1045 my_region
->free_pointer
= new_free_pointer
;
1047 /* Unless a `quick' alloc was requested, check whether the
1048 alloc region is almost empty. */
1050 (my_region
->end_addr
- my_region
->free_pointer
) <= 32) {
1051 /* If so, finished with the current region. */
1052 gc_alloc_update_page_tables(unboxed_p
, my_region
);
1053 /* Set up a new region. */
1054 gc_alloc_new_region(32 /*bytes*/, unboxed_p
, my_region
);
1057 return((void *)new_obj
);
1060 /* Else not enough free space in the current region: retry with a
1063 gc_alloc_update_page_tables(unboxed_p
, my_region
);
1064 gc_alloc_new_region(nbytes
, unboxed_p
, my_region
);
1065 return gc_alloc_with_region(nbytes
,unboxed_p
,my_region
,0);
1068 /* these are only used during GC: all allocation from the mutator calls
1069 * alloc() -> gc_alloc_with_region() with the appropriate per-thread
1073 gc_general_alloc(long nbytes
,int unboxed_p
,int quick_p
)
1075 struct alloc_region
*my_region
=
1076 unboxed_p
? &unboxed_region
: &boxed_region
;
1077 return gc_alloc_with_region(nbytes
,unboxed_p
, my_region
,quick_p
);
1080 static inline void *
1081 gc_quick_alloc(long nbytes
)
1083 return gc_general_alloc(nbytes
,ALLOC_BOXED
,ALLOC_QUICK
);
1086 static inline void *
1087 gc_quick_alloc_large(long nbytes
)
1089 return gc_general_alloc(nbytes
,ALLOC_BOXED
,ALLOC_QUICK
);
1092 static inline void *
1093 gc_alloc_unboxed(long nbytes
)
1095 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,0);
1098 static inline void *
1099 gc_quick_alloc_unboxed(long nbytes
)
1101 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,ALLOC_QUICK
);
1104 static inline void *
1105 gc_quick_alloc_large_unboxed(long nbytes
)
1107 return gc_general_alloc(nbytes
,ALLOC_UNBOXED
,ALLOC_QUICK
);
1111 * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
1114 extern long (*scavtab
[256])(lispobj
*where
, lispobj object
);
1115 extern lispobj (*transother
[256])(lispobj object
);
1116 extern long (*sizetab
[256])(lispobj
*where
);
1118 /* Copy a large boxed object. If the object is in a large object
1119 * region then it is simply promoted, else it is copied. If it's large
1120 * enough then it's copied to a large object region.
1122 * Vectors may have shrunk. If the object is not copied the space
1123 * needs to be reclaimed, and the page_tables corrected. */
1125 copy_large_object(lispobj object
, long nwords
)
1131 gc_assert(is_lisp_pointer(object
));
1132 gc_assert(from_space_p(object
));
1133 gc_assert((nwords
& 0x01) == 0);
1136 /* Check whether it's in a large object region. */
1137 first_page
= find_page_index((void *)object
);
1138 gc_assert(first_page
>= 0);
1140 if (page_table
[first_page
].large_object
) {
1142 /* Promote the object. */
1144 long remaining_bytes
;
1147 long old_bytes_used
;
1149 /* Note: Any page write-protection must be removed, else a
1150 * later scavenge_newspace may incorrectly not scavenge these
1151 * pages. This would not be necessary if they are added to the
1152 * new areas, but let's do it for them all (they'll probably
1153 * be written anyway?). */
1155 gc_assert(page_table
[first_page
].first_object_offset
== 0);
1157 next_page
= first_page
;
1158 remaining_bytes
= nwords
*N_WORD_BYTES
;
1159 while (remaining_bytes
> PAGE_BYTES
) {
1160 gc_assert(page_table
[next_page
].gen
== from_space
);
1161 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
1162 gc_assert(page_table
[next_page
].large_object
);
1163 gc_assert(page_table
[next_page
].first_object_offset
==
1164 -PAGE_BYTES
*(next_page
-first_page
));
1165 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
1167 page_table
[next_page
].gen
= new_space
;
1169 /* Remove any write-protection. We should be able to rely
1170 * on the write-protect flag to avoid redundant calls. */
1171 if (page_table
[next_page
].write_protected
) {
1172 os_protect(page_address(next_page
), PAGE_BYTES
, OS_VM_PROT_ALL
);
1173 page_table
[next_page
].write_protected
= 0;
1175 remaining_bytes
-= PAGE_BYTES
;
1179 /* Now only one page remains, but the object may have shrunk
1180 * so there may be more unused pages which will be freed. */
1182 /* The object may have shrunk but shouldn't have grown. */
1183 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
1185 page_table
[next_page
].gen
= new_space
;
1186 gc_assert(page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
);
1188 /* Adjust the bytes_used. */
1189 old_bytes_used
= page_table
[next_page
].bytes_used
;
1190 page_table
[next_page
].bytes_used
= remaining_bytes
;
1192 bytes_freed
= old_bytes_used
- remaining_bytes
;
1194 /* Free any remaining pages; needs care. */
1196 while ((old_bytes_used
== PAGE_BYTES
) &&
1197 (page_table
[next_page
].gen
== from_space
) &&
1198 (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
) &&
1199 page_table
[next_page
].large_object
&&
1200 (page_table
[next_page
].first_object_offset
==
1201 -(next_page
- first_page
)*PAGE_BYTES
)) {
1202 /* Checks out OK, free the page. Don't need to bother zeroing
1203 * pages as this should have been done before shrinking the
1204 * object. These pages shouldn't be write-protected as they
1205 * should be zero filled. */
1206 gc_assert(page_table
[next_page
].write_protected
== 0);
1208 old_bytes_used
= page_table
[next_page
].bytes_used
;
1209 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
1210 page_table
[next_page
].bytes_used
= 0;
1211 bytes_freed
+= old_bytes_used
;
1215 generations
[from_space
].bytes_allocated
-= N_WORD_BYTES
*nwords
+
1217 generations
[new_space
].bytes_allocated
+= N_WORD_BYTES
*nwords
;
1218 bytes_allocated
-= bytes_freed
;
1220 /* Add the region to the new_areas if requested. */
1221 add_new_area(first_page
,0,nwords
*N_WORD_BYTES
);
1225 /* Get tag of object. */
1226 tag
= lowtag_of(object
);
1228 /* Allocate space. */
1229 new = gc_quick_alloc_large(nwords
*N_WORD_BYTES
);
1231 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1233 /* Return Lisp pointer of new object. */
1234 return ((lispobj
) new) | tag
;
1238 /* to copy unboxed objects */
1240 copy_unboxed_object(lispobj object
, long nwords
)
1245 gc_assert(is_lisp_pointer(object
));
1246 gc_assert(from_space_p(object
));
1247 gc_assert((nwords
& 0x01) == 0);
1249 /* Get tag of object. */
1250 tag
= lowtag_of(object
);
1252 /* Allocate space. */
1253 new = gc_quick_alloc_unboxed(nwords
*N_WORD_BYTES
);
1255 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1257 /* Return Lisp pointer of new object. */
1258 return ((lispobj
) new) | tag
;
1261 /* to copy large unboxed objects
1263 * If the object is in a large object region then it is simply
1264 * promoted, else it is copied. If it's large enough then it's copied
1265 * to a large object region.
1267 * Bignums and vectors may have shrunk. If the object is not copied
1268 * the space needs to be reclaimed, and the page_tables corrected.
1270 * KLUDGE: There's a lot of cut-and-paste duplication between this
1271 * function and copy_large_object(..). -- WHN 20000619 */
1273 copy_large_unboxed_object(lispobj object
, long nwords
)
1279 gc_assert(is_lisp_pointer(object
));
1280 gc_assert(from_space_p(object
));
1281 gc_assert((nwords
& 0x01) == 0);
1283 if ((nwords
> 1024*1024) && gencgc_verbose
)
1284 FSHOW((stderr
, "/copy_large_unboxed_object: %d bytes\n", nwords
*N_WORD_BYTES
));
1286 /* Check whether it's a large object. */
1287 first_page
= find_page_index((void *)object
);
1288 gc_assert(first_page
>= 0);
1290 if (page_table
[first_page
].large_object
) {
1291 /* Promote the object. Note: Unboxed objects may have been
1292 * allocated to a BOXED region so it may be necessary to
1293 * change the region to UNBOXED. */
1294 long remaining_bytes
;
1297 long old_bytes_used
;
1299 gc_assert(page_table
[first_page
].first_object_offset
== 0);
1301 next_page
= first_page
;
1302 remaining_bytes
= nwords
*N_WORD_BYTES
;
1303 while (remaining_bytes
> PAGE_BYTES
) {
1304 gc_assert(page_table
[next_page
].gen
== from_space
);
1305 gc_assert((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
1306 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
));
1307 gc_assert(page_table
[next_page
].large_object
);
1308 gc_assert(page_table
[next_page
].first_object_offset
==
1309 -PAGE_BYTES
*(next_page
-first_page
));
1310 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
1312 page_table
[next_page
].gen
= new_space
;
1313 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
1314 remaining_bytes
-= PAGE_BYTES
;
1318 /* Now only one page remains, but the object may have shrunk so
1319 * there may be more unused pages which will be freed. */
1321 /* Object may have shrunk but shouldn't have grown - check. */
1322 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
1324 page_table
[next_page
].gen
= new_space
;
1325 page_table
[next_page
].allocated
= UNBOXED_PAGE_FLAG
;
1327 /* Adjust the bytes_used. */
1328 old_bytes_used
= page_table
[next_page
].bytes_used
;
1329 page_table
[next_page
].bytes_used
= remaining_bytes
;
1331 bytes_freed
= old_bytes_used
- remaining_bytes
;
1333 /* Free any remaining pages; needs care. */
1335 while ((old_bytes_used
== PAGE_BYTES
) &&
1336 (page_table
[next_page
].gen
== from_space
) &&
1337 ((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
1338 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)) &&
1339 page_table
[next_page
].large_object
&&
1340 (page_table
[next_page
].first_object_offset
==
1341 -(next_page
- first_page
)*PAGE_BYTES
)) {
1342 /* Checks out OK, free the page. Don't need to both zeroing
1343 * pages as this should have been done before shrinking the
1344 * object. These pages shouldn't be write-protected, even if
1345 * boxed they should be zero filled. */
1346 gc_assert(page_table
[next_page
].write_protected
== 0);
1348 old_bytes_used
= page_table
[next_page
].bytes_used
;
1349 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
1350 page_table
[next_page
].bytes_used
= 0;
1351 bytes_freed
+= old_bytes_used
;
1355 if ((bytes_freed
> 0) && gencgc_verbose
)
1357 "/copy_large_unboxed bytes_freed=%d\n",
1360 generations
[from_space
].bytes_allocated
-= nwords
*N_WORD_BYTES
+ bytes_freed
;
1361 generations
[new_space
].bytes_allocated
+= nwords
*N_WORD_BYTES
;
1362 bytes_allocated
-= bytes_freed
;
1367 /* Get tag of object. */
1368 tag
= lowtag_of(object
);
1370 /* Allocate space. */
1371 new = gc_quick_alloc_large_unboxed(nwords
*N_WORD_BYTES
);
1373 /* Copy the object. */
1374 memcpy(new,native_pointer(object
),nwords
*N_WORD_BYTES
);
1376 /* Return Lisp pointer of new object. */
1377 return ((lispobj
) new) | tag
;
1386 * code and code-related objects
1389 static lispobj trans_fun_header(lispobj object);
1390 static lispobj trans_boxed(lispobj object);
1393 /* Scan a x86 compiled code object, looking for possible fixups that
1394 * have been missed after a move.
1396 * Two types of fixups are needed:
1397 * 1. Absolute fixups to within the code object.
1398 * 2. Relative fixups to outside the code object.
1400 * Currently only absolute fixups to the constant vector, or to the
1401 * code area are checked. */
1403 sniff_code_object(struct code
*code
, unsigned displacement
)
1405 long nheader_words
, ncode_words
, nwords
;
1407 void *constants_start_addr
, *constants_end_addr
;
1408 void *code_start_addr
, *code_end_addr
;
1409 int fixup_found
= 0;
1411 if (!check_code_fixups
)
1414 ncode_words
= fixnum_value(code
->code_size
);
1415 nheader_words
= HeaderValue(*(lispobj
*)code
);
1416 nwords
= ncode_words
+ nheader_words
;
1418 constants_start_addr
= (void *)code
+ 5*N_WORD_BYTES
;
1419 constants_end_addr
= (void *)code
+ nheader_words
*N_WORD_BYTES
;
1420 code_start_addr
= (void *)code
+ nheader_words
*N_WORD_BYTES
;
1421 code_end_addr
= (void *)code
+ nwords
*N_WORD_BYTES
;
1423 /* Work through the unboxed code. */
1424 for (p
= code_start_addr
; p
< code_end_addr
; p
++) {
1425 void *data
= *(void **)p
;
1426 unsigned d1
= *((unsigned char *)p
- 1);
1427 unsigned d2
= *((unsigned char *)p
- 2);
1428 unsigned d3
= *((unsigned char *)p
- 3);
1429 unsigned d4
= *((unsigned char *)p
- 4);
1431 unsigned d5
= *((unsigned char *)p
- 5);
1432 unsigned d6
= *((unsigned char *)p
- 6);
1435 /* Check for code references. */
1436 /* Check for a 32 bit word that looks like an absolute
1437 reference to within the code adea of the code object. */
1438 if ((data
>= (code_start_addr
-displacement
))
1439 && (data
< (code_end_addr
-displacement
))) {
1440 /* function header */
1442 && (((unsigned)p
- 4 - 4*HeaderValue(*((unsigned *)p
-1))) == (unsigned)code
)) {
1443 /* Skip the function header */
1447 /* the case of PUSH imm32 */
1451 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1452 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1453 FSHOW((stderr
, "/PUSH $0x%.8x\n", data
));
1455 /* the case of MOV [reg-8],imm32 */
1457 && (d2
==0x40 || d2
==0x41 || d2
==0x42 || d2
==0x43
1458 || d2
==0x45 || d2
==0x46 || d2
==0x47)
1462 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1463 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1464 FSHOW((stderr
, "/MOV [reg-8],$0x%.8x\n", data
));
1466 /* the case of LEA reg,[disp32] */
1467 if ((d2
== 0x8d) && ((d1
& 0xc7) == 5)) {
1470 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1471 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1472 FSHOW((stderr
,"/LEA reg,[$0x%.8x]\n", data
));
1476 /* Check for constant references. */
1477 /* Check for a 32 bit word that looks like an absolute
1478 reference to within the constant vector. Constant references
1480 if ((data
>= (constants_start_addr
-displacement
))
1481 && (data
< (constants_end_addr
-displacement
))
1482 && (((unsigned)data
& 0x3) == 0)) {
1487 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1488 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1489 FSHOW((stderr
,"/MOV eax,0x%.8x\n", data
));
1492 /* the case of MOV m32,EAX */
1496 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1497 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1498 FSHOW((stderr
, "/MOV 0x%.8x,eax\n", data
));
1501 /* the case of CMP m32,imm32 */
1502 if ((d1
== 0x3d) && (d2
== 0x81)) {
1505 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1506 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1508 FSHOW((stderr
, "/CMP 0x%.8x,immed32\n", data
));
1511 /* Check for a mod=00, r/m=101 byte. */
1512 if ((d1
& 0xc7) == 5) {
1517 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1518 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1519 FSHOW((stderr
,"/CMP 0x%.8x,reg\n", data
));
1521 /* the case of CMP reg32,m32 */
1525 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1526 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1527 FSHOW((stderr
, "/CMP reg32,0x%.8x\n", data
));
1529 /* the case of MOV m32,reg32 */
1533 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1534 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1535 FSHOW((stderr
, "/MOV 0x%.8x,reg32\n", data
));
1537 /* the case of MOV reg32,m32 */
1541 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1542 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1543 FSHOW((stderr
, "/MOV reg32,0x%.8x\n", data
));
1545 /* the case of LEA reg32,m32 */
1549 "abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1550 p
, d6
, d5
, d4
, d3
, d2
, d1
, data
));
1551 FSHOW((stderr
, "/LEA reg32,0x%.8x\n", data
));
1557 /* If anything was found, print some information on the code
1561 "/compiled code object at %x: header words = %d, code words = %d\n",
1562 code
, nheader_words
, ncode_words
));
1564 "/const start = %x, end = %x\n",
1565 constants_start_addr
, constants_end_addr
));
1567 "/code start = %x, end = %x\n",
1568 code_start_addr
, code_end_addr
));
1573 gencgc_apply_code_fixups(struct code
*old_code
, struct code
*new_code
)
1575 long nheader_words
, ncode_words
, nwords
;
1576 void *constants_start_addr
, *constants_end_addr
;
1577 void *code_start_addr
, *code_end_addr
;
1578 lispobj fixups
= NIL
;
1579 unsigned displacement
= (unsigned)new_code
- (unsigned)old_code
;
1580 struct vector
*fixups_vector
;
1582 ncode_words
= fixnum_value(new_code
->code_size
);
1583 nheader_words
= HeaderValue(*(lispobj
*)new_code
);
1584 nwords
= ncode_words
+ nheader_words
;
1586 "/compiled code object at %x: header words = %d, code words = %d\n",
1587 new_code, nheader_words, ncode_words)); */
1588 constants_start_addr
= (void *)new_code
+ 5*N_WORD_BYTES
;
1589 constants_end_addr
= (void *)new_code
+ nheader_words
*N_WORD_BYTES
;
1590 code_start_addr
= (void *)new_code
+ nheader_words
*N_WORD_BYTES
;
1591 code_end_addr
= (void *)new_code
+ nwords
*N_WORD_BYTES
;
1594 "/const start = %x, end = %x\n",
1595 constants_start_addr,constants_end_addr));
1597 "/code start = %x; end = %x\n",
1598 code_start_addr,code_end_addr));
1601 /* The first constant should be a pointer to the fixups for this
1602 code objects. Check. */
1603 fixups
= new_code
->constants
[0];
1605 /* It will be 0 or the unbound-marker if there are no fixups (as
1606 * will be the case if the code object has been purified, for
1607 * example) and will be an other pointer if it is valid. */
1608 if ((fixups
== 0) || (fixups
== UNBOUND_MARKER_WIDETAG
) ||
1609 !is_lisp_pointer(fixups
)) {
1610 /* Check for possible errors. */
1611 if (check_code_fixups
)
1612 sniff_code_object(new_code
, displacement
);
1617 fixups_vector
= (struct vector
*)native_pointer(fixups
);
1619 /* Could be pointing to a forwarding pointer. */
1620 /* FIXME is this always in from_space? if so, could replace this code with
1621 * forwarding_pointer_p/forwarding_pointer_value */
1622 if (is_lisp_pointer(fixups
) &&
1623 (find_page_index((void*)fixups_vector
) != -1) &&
1624 (fixups_vector
->header
== 0x01)) {
1625 /* If so, then follow it. */
1626 /*SHOW("following pointer to a forwarding pointer");*/
1627 fixups_vector
= (struct vector
*)native_pointer((lispobj
)fixups_vector
->length
);
1630 /*SHOW("got fixups");*/
1632 if (widetag_of(fixups_vector
->header
) == SIMPLE_ARRAY_WORD_WIDETAG
) {
1633 /* Got the fixups for the code block. Now work through the vector,
1634 and apply a fixup at each address. */
1635 long length
= fixnum_value(fixups_vector
->length
);
1637 for (i
= 0; i
< length
; i
++) {
1638 unsigned offset
= fixups_vector
->data
[i
];
1639 /* Now check the current value of offset. */
1640 unsigned old_value
=
1641 *(unsigned *)((unsigned)code_start_addr
+ offset
);
1643 /* If it's within the old_code object then it must be an
1644 * absolute fixup (relative ones are not saved) */
1645 if ((old_value
>= (unsigned)old_code
)
1646 && (old_value
< ((unsigned)old_code
+ nwords
*N_WORD_BYTES
)))
1647 /* So add the dispacement. */
1648 *(unsigned *)((unsigned)code_start_addr
+ offset
) =
1649 old_value
+ displacement
;
1651 /* It is outside the old code object so it must be a
1652 * relative fixup (absolute fixups are not saved). So
1653 * subtract the displacement. */
1654 *(unsigned *)((unsigned)code_start_addr
+ offset
) =
1655 old_value
- displacement
;
1658 fprintf(stderr
, "widetag of fixup vector is %d\n", widetag_of(fixups_vector
->header
));
1661 /* Check for possible errors. */
1662 if (check_code_fixups
) {
1663 sniff_code_object(new_code
,displacement
);
1669 trans_boxed_large(lispobj object
)
1672 unsigned long length
;
1674 gc_assert(is_lisp_pointer(object
));
1676 header
= *((lispobj
*) native_pointer(object
));
1677 length
= HeaderValue(header
) + 1;
1678 length
= CEILING(length
, 2);
1680 return copy_large_object(object
, length
);
1685 trans_unboxed_large(lispobj object
)
1688 unsigned long length
;
1691 gc_assert(is_lisp_pointer(object
));
1693 header
= *((lispobj
*) native_pointer(object
));
1694 length
= HeaderValue(header
) + 1;
1695 length
= CEILING(length
, 2);
1697 return copy_large_unboxed_object(object
, length
);
1702 * vector-like objects
1706 /* FIXME: What does this mean? */
1707 int gencgc_hash
= 1;
1710 scav_vector(lispobj
*where
, lispobj object
)
1712 unsigned long kv_length
;
1714 unsigned long length
= 0; /* (0 = dummy to stop GCC warning) */
1715 lispobj
*hash_table
;
1716 lispobj empty_symbol
;
1717 unsigned long *index_vector
= NULL
; /* (NULL = dummy to stop GCC warning) */
1718 unsigned long *next_vector
= NULL
; /* (NULL = dummy to stop GCC warning) */
1719 unsigned long *hash_vector
= NULL
; /* (NULL = dummy to stop GCC warning) */
1721 unsigned next_vector_length
= 0;
1723 /* FIXME: A comment explaining this would be nice. It looks as
1724 * though SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based
1725 * hash tables in the Lisp HASH-TABLE code, and nowhere else. */
1726 if (HeaderValue(object
) != subtype_VectorValidHashing
)
1730 /* This is set for backward compatibility. FIXME: Do we need
1733 (subtype_VectorMustRehash
<<N_WIDETAG_BITS
) | SIMPLE_VECTOR_WIDETAG
;
1737 kv_length
= fixnum_value(where
[1]);
1738 kv_vector
= where
+ 2; /* Skip the header and length. */
1739 /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
1741 /* Scavenge element 0, which may be a hash-table structure. */
1742 scavenge(where
+2, 1);
1743 if (!is_lisp_pointer(where
[2])) {
1744 lose("no pointer at %x in hash table", where
[2]);
1746 hash_table
= (lispobj
*)native_pointer(where
[2]);
1747 /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
1748 if (widetag_of(hash_table
[0]) != INSTANCE_HEADER_WIDETAG
) {
1749 lose("hash table not instance (%x at %x)", hash_table
[0], hash_table
);
1752 /* Scavenge element 1, which should be some internal symbol that
1753 * the hash table code reserves for marking empty slots. */
1754 scavenge(where
+3, 1);
1755 if (!is_lisp_pointer(where
[3])) {
1756 lose("not empty-hash-table-slot symbol pointer: %x", where
[3]);
1758 empty_symbol
= where
[3];
1759 /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
1760 if (widetag_of(*(lispobj
*)native_pointer(empty_symbol
)) !=
1761 SYMBOL_HEADER_WIDETAG
) {
1762 lose("not a symbol where empty-hash-table-slot symbol expected: %x",
1763 *(lispobj
*)native_pointer(empty_symbol
));
1766 /* Scavenge hash table, which will fix the positions of the other
1767 * needed objects. */
1768 scavenge(hash_table
, 16);
1770 /* Cross-check the kv_vector. */
1771 if (where
!= (lispobj
*)native_pointer(hash_table
[9])) {
1772 lose("hash_table table!=this table %x", hash_table
[9]);
1776 weak_p_obj
= hash_table
[10];
1780 lispobj index_vector_obj
= hash_table
[13];
1782 if (is_lisp_pointer(index_vector_obj
) &&
1783 (widetag_of(*(lispobj
*)native_pointer(index_vector_obj
)) ==
1784 SIMPLE_ARRAY_WORD_WIDETAG
)) {
1785 index_vector
= ((lispobj
*)native_pointer(index_vector_obj
)) + 2;
1786 /*FSHOW((stderr, "/index_vector = %x\n",index_vector));*/
1787 length
= fixnum_value(((lispobj
*)native_pointer(index_vector_obj
))[1]);
1788 /*FSHOW((stderr, "/length = %d\n", length));*/
1790 lose("invalid index_vector %x", index_vector_obj
);
1796 lispobj next_vector_obj
= hash_table
[14];
1798 if (is_lisp_pointer(next_vector_obj
) &&
1799 (widetag_of(*(lispobj
*)native_pointer(next_vector_obj
)) ==
1800 SIMPLE_ARRAY_WORD_WIDETAG
)) {
1801 next_vector
= ((lispobj
*)native_pointer(next_vector_obj
)) + 2;
1802 /*FSHOW((stderr, "/next_vector = %x\n", next_vector));*/
1803 next_vector_length
= fixnum_value(((lispobj
*)native_pointer(next_vector_obj
))[1]);
1804 /*FSHOW((stderr, "/next_vector_length = %d\n", next_vector_length));*/
1806 lose("invalid next_vector %x", next_vector_obj
);
1810 /* maybe hash vector */
1812 /* FIXME: This bare "15" offset should become a symbolic
1813 * expression of some sort. And all the other bare offsets
1814 * too. And the bare "16" in scavenge(hash_table, 16). And
1815 * probably other stuff too. Ugh.. */
1816 lispobj hash_vector_obj
= hash_table
[15];
1818 if (is_lisp_pointer(hash_vector_obj
) &&
1819 (widetag_of(*(lispobj
*)native_pointer(hash_vector_obj
)) ==
1820 SIMPLE_ARRAY_WORD_WIDETAG
)){
1821 hash_vector
= ((lispobj
*)native_pointer(hash_vector_obj
)) + 2;
1822 /*FSHOW((stderr, "/hash_vector = %x\n", hash_vector));*/
1823 gc_assert(fixnum_value(((lispobj
*)native_pointer(hash_vector_obj
))[1])
1824 == next_vector_length
);
1827 /*FSHOW((stderr, "/no hash_vector: %x\n", hash_vector_obj));*/
1831 /* These lengths could be different as the index_vector can be a
1832 * different length from the others, a larger index_vector could help
1833 * reduce collisions. */
1834 gc_assert(next_vector_length
*2 == kv_length
);
1836 /* now all set up.. */
1838 /* Work through the KV vector. */
1841 for (i
= 1; i
< next_vector_length
; i
++) {
1842 lispobj old_key
= kv_vector
[2*i
];
1844 #if N_WORD_BITS == 32
1845 unsigned long old_index
= (old_key
& 0x1fffffff)%length
;
1846 #elif N_WORD_BITS == 64
1847 unsigned long old_index
= (old_key
& 0x1fffffffffffffff)%length
;
1850 /* Scavenge the key and value. */
1851 scavenge(&kv_vector
[2*i
],2);
1853 /* Check whether the key has moved and is EQ based. */
1855 lispobj new_key
= kv_vector
[2*i
];
1856 #if N_WORD_BITS == 32
1857 unsigned long new_index
= (new_key
& 0x1fffffff)%length
;
1858 #elif N_WORD_BITS == 64
1859 unsigned long new_index
= (new_key
& 0x1fffffffffffffff)%length
;
1862 if ((old_index
!= new_index
) &&
1863 ((!hash_vector
) || (hash_vector
[i
] == 0x80000000)) &&
1864 ((new_key
!= empty_symbol
) ||
1865 (kv_vector
[2*i
] != empty_symbol
))) {
1868 "* EQ key %d moved from %x to %x; index %d to %d\n",
1869 i, old_key, new_key, old_index, new_index));*/
1871 if (index_vector
[old_index
] != 0) {
1872 /*FSHOW((stderr, "/P1 %d\n", index_vector[old_index]));*/
1874 /* Unlink the key from the old_index chain. */
1875 if (index_vector
[old_index
] == i
) {
1876 /*FSHOW((stderr, "/P2a %d\n", next_vector[i]));*/
1877 index_vector
[old_index
] = next_vector
[i
];
1878 /* Link it into the needing rehash chain. */
1879 next_vector
[i
] = fixnum_value(hash_table
[11]);
1880 hash_table
[11] = make_fixnum(i
);
1883 unsigned prior
= index_vector
[old_index
];
1884 unsigned next
= next_vector
[prior
];
1886 /*FSHOW((stderr, "/P3a %d %d\n", prior, next));*/
1889 /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
1892 next_vector
[prior
] = next_vector
[next
];
1893 /* Link it into the needing rehash
1896 fixnum_value(hash_table
[11]);
1897 hash_table
[11] = make_fixnum(next
);
1902 next
= next_vector
[next
];
1910 return (CEILING(kv_length
+ 2, 2));
1919 /* XX This is a hack adapted from cgc.c. These don't work too
1920 * efficiently with the gencgc as a list of the weak pointers is
1921 * maintained within the objects which causes writes to the pages. A
1922 * limited attempt is made to avoid unnecessary writes, but this needs
1924 #define WEAK_POINTER_NWORDS \
1925 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
1928 scav_weak_pointer(lispobj
*where
, lispobj object
)
1930 struct weak_pointer
*wp
= weak_pointers
;
1931 /* Push the weak pointer onto the list of weak pointers.
1932 * Do I have to watch for duplicates? Originally this was
1933 * part of trans_weak_pointer but that didn't work in the
1934 * case where the WP was in a promoted region.
1937 /* Check whether it's already in the list. */
1938 while (wp
!= NULL
) {
1939 if (wp
== (struct weak_pointer
*)where
) {
1945 /* Add it to the start of the list. */
1946 wp
= (struct weak_pointer
*)where
;
1947 if (wp
->next
!= weak_pointers
) {
1948 wp
->next
= weak_pointers
;
1950 /*SHOW("avoided write to weak pointer");*/
1955 /* Do not let GC scavenge the value slot of the weak pointer.
1956 * (That is why it is a weak pointer.) */
1958 return WEAK_POINTER_NWORDS
;
1963 search_read_only_space(void *pointer
)
1965 lispobj
*start
= (lispobj
*) READ_ONLY_SPACE_START
;
1966 lispobj
*end
= (lispobj
*) SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0);
1967 if ((pointer
< (void *)start
) || (pointer
>= (void *)end
))
1969 return (gc_search_space(start
,
1970 (((lispobj
*)pointer
)+2)-start
,
1971 (lispobj
*) pointer
));
1975 search_static_space(void *pointer
)
1977 lispobj
*start
= (lispobj
*)STATIC_SPACE_START
;
1978 lispobj
*end
= (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0);
1979 if ((pointer
< (void *)start
) || (pointer
>= (void *)end
))
1981 return (gc_search_space(start
,
1982 (((lispobj
*)pointer
)+2)-start
,
1983 (lispobj
*) pointer
));
1986 /* a faster version for searching the dynamic space. This will work even
1987 * if the object is in a current allocation region. */
1989 search_dynamic_space(void *pointer
)
1991 long page_index
= find_page_index(pointer
);
1994 /* The address may be invalid, so do some checks. */
1995 if ((page_index
== -1) ||
1996 (page_table
[page_index
].allocated
== FREE_PAGE_FLAG
))
1998 start
= (lispobj
*)((void *)page_address(page_index
)
1999 + page_table
[page_index
].first_object_offset
);
2000 return (gc_search_space(start
,
2001 (((lispobj
*)pointer
)+2)-start
,
2002 (lispobj
*)pointer
));
2005 /* Is there any possibility that pointer is a valid Lisp object
2006 * reference, and/or something else (e.g. subroutine call return
2007 * address) which should prevent us from moving the referred-to thing?
2008 * This is called from preserve_pointers() */
2010 possibly_valid_dynamic_space_pointer(lispobj
*pointer
)
2012 lispobj
*start_addr
;
2014 /* Find the object start address. */
2015 if ((start_addr
= search_dynamic_space(pointer
)) == NULL
) {
2019 /* We need to allow raw pointers into Code objects for return
2020 * addresses. This will also pick up pointers to functions in code
2022 if (widetag_of(*start_addr
) == CODE_HEADER_WIDETAG
) {
2023 /* XXX could do some further checks here */
2027 /* If it's not a return address then it needs to be a valid Lisp
2029 if (!is_lisp_pointer((lispobj
)pointer
)) {
2033 /* Check that the object pointed to is consistent with the pointer
2036 switch (lowtag_of((lispobj
)pointer
)) {
2037 case FUN_POINTER_LOWTAG
:
2038 /* Start_addr should be the enclosing code object, or a closure
2040 switch (widetag_of(*start_addr
)) {
2041 case CODE_HEADER_WIDETAG
:
2042 /* This case is probably caught above. */
2044 case CLOSURE_HEADER_WIDETAG
:
2045 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
2046 if ((unsigned)pointer
!=
2047 ((unsigned)start_addr
+FUN_POINTER_LOWTAG
)) {
2051 pointer
, start_addr
, *start_addr
));
2059 pointer
, start_addr
, *start_addr
));
2063 case LIST_POINTER_LOWTAG
:
2064 if ((unsigned)pointer
!=
2065 ((unsigned)start_addr
+LIST_POINTER_LOWTAG
)) {
2069 pointer
, start_addr
, *start_addr
));
2072 /* Is it plausible cons? */
2073 if ((is_lisp_pointer(start_addr
[0])
2074 || (fixnump(start_addr
[0]))
2075 || (widetag_of(start_addr
[0]) == CHARACTER_WIDETAG
)
2076 #if N_WORD_BITS == 64
2077 || (widetag_of(start_addr
[0]) == SINGLE_FLOAT_WIDETAG
)
2079 || (widetag_of(start_addr
[0]) == UNBOUND_MARKER_WIDETAG
))
2080 && (is_lisp_pointer(start_addr
[1])
2081 || (fixnump(start_addr
[1]))
2082 || (widetag_of(start_addr
[1]) == CHARACTER_WIDETAG
)
2083 #if N_WORD_BITS == 64
2084 || (widetag_of(start_addr
[1]) == SINGLE_FLOAT_WIDETAG
)
2086 || (widetag_of(start_addr
[1]) == UNBOUND_MARKER_WIDETAG
)))
2092 pointer
, start_addr
, *start_addr
));
2095 case INSTANCE_POINTER_LOWTAG
:
2096 if ((unsigned)pointer
!=
2097 ((unsigned)start_addr
+INSTANCE_POINTER_LOWTAG
)) {
2101 pointer
, start_addr
, *start_addr
));
2104 if (widetag_of(start_addr
[0]) != INSTANCE_HEADER_WIDETAG
) {
2108 pointer
, start_addr
, *start_addr
));
2112 case OTHER_POINTER_LOWTAG
:
2113 if ((unsigned)pointer
!=
2114 ((int)start_addr
+OTHER_POINTER_LOWTAG
)) {
2118 pointer
, start_addr
, *start_addr
));
2121 /* Is it plausible? Not a cons. XXX should check the headers. */
2122 if (is_lisp_pointer(start_addr
[0]) || ((start_addr
[0] & 3) == 0)) {
2126 pointer
, start_addr
, *start_addr
));
2129 switch (widetag_of(start_addr
[0])) {
2130 case UNBOUND_MARKER_WIDETAG
:
2131 case CHARACTER_WIDETAG
:
2132 #if N_WORD_BITS == 64
2133 case SINGLE_FLOAT_WIDETAG
:
2138 pointer
, start_addr
, *start_addr
));
2141 /* only pointed to by function pointers? */
2142 case CLOSURE_HEADER_WIDETAG
:
2143 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
2147 pointer
, start_addr
, *start_addr
));
2150 case INSTANCE_HEADER_WIDETAG
:
2154 pointer
, start_addr
, *start_addr
));
2157 /* the valid other immediate pointer objects */
2158 case SIMPLE_VECTOR_WIDETAG
:
2160 case COMPLEX_WIDETAG
:
2161 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
2162 case COMPLEX_SINGLE_FLOAT_WIDETAG
:
2164 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
2165 case COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2167 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
2168 case COMPLEX_LONG_FLOAT_WIDETAG
:
2170 case SIMPLE_ARRAY_WIDETAG
:
2171 case COMPLEX_BASE_STRING_WIDETAG
:
2172 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
2173 case COMPLEX_CHARACTER_STRING_WIDETAG
:
2175 case COMPLEX_VECTOR_NIL_WIDETAG
:
2176 case COMPLEX_BIT_VECTOR_WIDETAG
:
2177 case COMPLEX_VECTOR_WIDETAG
:
2178 case COMPLEX_ARRAY_WIDETAG
:
2179 case VALUE_CELL_HEADER_WIDETAG
:
2180 case SYMBOL_HEADER_WIDETAG
:
2182 case CODE_HEADER_WIDETAG
:
2183 case BIGNUM_WIDETAG
:
2184 #if N_WORD_BITS != 64
2185 case SINGLE_FLOAT_WIDETAG
:
2187 case DOUBLE_FLOAT_WIDETAG
:
2188 #ifdef LONG_FLOAT_WIDETAG
2189 case LONG_FLOAT_WIDETAG
:
2191 case SIMPLE_BASE_STRING_WIDETAG
:
2192 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2193 case SIMPLE_CHARACTER_STRING_WIDETAG
:
2195 case SIMPLE_BIT_VECTOR_WIDETAG
:
2196 case SIMPLE_ARRAY_NIL_WIDETAG
:
2197 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
2198 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
2199 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
2200 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
2201 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
2202 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
2203 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2204 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
2206 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
2207 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
2208 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2209 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
2211 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2212 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
2214 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2215 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
2217 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2218 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
2220 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2221 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
2223 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2224 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
2226 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2227 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
2229 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2230 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
2232 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2233 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
2235 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
2236 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
2237 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2238 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
2240 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2241 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
2243 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2244 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2246 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2247 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
2250 case WEAK_POINTER_WIDETAG
:
2257 pointer
, start_addr
, *start_addr
));
2265 pointer
, start_addr
, *start_addr
));
2273 /* Adjust large bignum and vector objects. This will adjust the
2274 * allocated region if the size has shrunk, and move unboxed objects
2275 * into unboxed pages. The pages are not promoted here, and the
2276 * promoted region is not added to the new_regions; this is really
2277 * only designed to be called from preserve_pointer(). Shouldn't fail
2278 * if this is missed, just may delay the moving of objects to unboxed
2279 * pages, and the freeing of pages. */
2281 maybe_adjust_large_object(lispobj
*where
)
2286 long remaining_bytes
;
2289 long old_bytes_used
;
2293 /* Check whether it's a vector or bignum object. */
2294 switch (widetag_of(where
[0])) {
2295 case SIMPLE_VECTOR_WIDETAG
:
2296 boxed
= BOXED_PAGE_FLAG
;
2298 case BIGNUM_WIDETAG
:
2299 case SIMPLE_BASE_STRING_WIDETAG
:
2300 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2301 case SIMPLE_CHARACTER_STRING_WIDETAG
:
2303 case SIMPLE_BIT_VECTOR_WIDETAG
:
2304 case SIMPLE_ARRAY_NIL_WIDETAG
:
2305 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
2306 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
2307 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
2308 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
2309 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
2310 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
2311 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2312 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
2314 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
2315 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
2316 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2317 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
2319 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2320 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
2322 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2323 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
2325 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2326 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
2328 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2329 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
2331 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2332 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
2334 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2335 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
2337 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2338 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
2340 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2341 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
2343 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
2344 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
2345 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2346 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
2348 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2349 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
2351 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2352 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
2354 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2355 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
2357 boxed
= UNBOXED_PAGE_FLAG
;
2363 /* Find its current size. */
2364 nwords
= (sizetab
[widetag_of(where
[0])])(where
);
2366 first_page
= find_page_index((void *)where
);
2367 gc_assert(first_page
>= 0);
2369 /* Note: Any page write-protection must be removed, else a later
2370 * scavenge_newspace may incorrectly not scavenge these pages.
2371 * This would not be necessary if they are added to the new areas,
2372 * but lets do it for them all (they'll probably be written
2375 gc_assert(page_table
[first_page
].first_object_offset
== 0);
2377 next_page
= first_page
;
2378 remaining_bytes
= nwords
*N_WORD_BYTES
;
2379 while (remaining_bytes
> PAGE_BYTES
) {
2380 gc_assert(page_table
[next_page
].gen
== from_space
);
2381 gc_assert((page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)
2382 || (page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
));
2383 gc_assert(page_table
[next_page
].large_object
);
2384 gc_assert(page_table
[next_page
].first_object_offset
==
2385 -PAGE_BYTES
*(next_page
-first_page
));
2386 gc_assert(page_table
[next_page
].bytes_used
== PAGE_BYTES
);
2388 page_table
[next_page
].allocated
= boxed
;
2390 /* Shouldn't be write-protected at this stage. Essential that the
2392 gc_assert(!page_table
[next_page
].write_protected
);
2393 remaining_bytes
-= PAGE_BYTES
;
2397 /* Now only one page remains, but the object may have shrunk so
2398 * there may be more unused pages which will be freed. */
2400 /* Object may have shrunk but shouldn't have grown - check. */
2401 gc_assert(page_table
[next_page
].bytes_used
>= remaining_bytes
);
2403 page_table
[next_page
].allocated
= boxed
;
2404 gc_assert(page_table
[next_page
].allocated
==
2405 page_table
[first_page
].allocated
);
2407 /* Adjust the bytes_used. */
2408 old_bytes_used
= page_table
[next_page
].bytes_used
;
2409 page_table
[next_page
].bytes_used
= remaining_bytes
;
2411 bytes_freed
= old_bytes_used
- remaining_bytes
;
2413 /* Free any remaining pages; needs care. */
2415 while ((old_bytes_used
== PAGE_BYTES
) &&
2416 (page_table
[next_page
].gen
== from_space
) &&
2417 ((page_table
[next_page
].allocated
== UNBOXED_PAGE_FLAG
)
2418 || (page_table
[next_page
].allocated
== BOXED_PAGE_FLAG
)) &&
2419 page_table
[next_page
].large_object
&&
2420 (page_table
[next_page
].first_object_offset
==
2421 -(next_page
- first_page
)*PAGE_BYTES
)) {
2422 /* It checks out OK, free the page. We don't need to both zeroing
2423 * pages as this should have been done before shrinking the
2424 * object. These pages shouldn't be write protected as they
2425 * should be zero filled. */
2426 gc_assert(page_table
[next_page
].write_protected
== 0);
2428 old_bytes_used
= page_table
[next_page
].bytes_used
;
2429 page_table
[next_page
].allocated
= FREE_PAGE_FLAG
;
2430 page_table
[next_page
].bytes_used
= 0;
2431 bytes_freed
+= old_bytes_used
;
2435 if ((bytes_freed
> 0) && gencgc_verbose
) {
2437 "/maybe_adjust_large_object() freed %d\n",
2441 generations
[from_space
].bytes_allocated
-= bytes_freed
;
2442 bytes_allocated
-= bytes_freed
;
2447 /* Take a possible pointer to a Lisp object and mark its page in the
2448 * page_table so that it will not be relocated during a GC.
2450 * This involves locating the page it points to, then backing up to
2451 * the start of its region, then marking all pages dont_move from there
2452 * up to the first page that's not full or has a different generation
2454 * It is assumed that all the page static flags have been cleared at
2455 * the start of a GC.
2457 * It is also assumed that the current gc_alloc() region has been
2458 * flushed and the tables updated. */
2460 preserve_pointer(void *addr
)
2462 long addr_page_index
= find_page_index(addr
);
2465 unsigned region_allocation
;
2467 /* quick check 1: Address is quite likely to have been invalid. */
2468 if ((addr_page_index
== -1)
2469 || (page_table
[addr_page_index
].allocated
== FREE_PAGE_FLAG
)
2470 || (page_table
[addr_page_index
].bytes_used
== 0)
2471 || (page_table
[addr_page_index
].gen
!= from_space
)
2472 /* Skip if already marked dont_move. */
2473 || (page_table
[addr_page_index
].dont_move
!= 0))
2475 gc_assert(!(page_table
[addr_page_index
].allocated
&OPEN_REGION_PAGE_FLAG
));
2476 /* (Now that we know that addr_page_index is in range, it's
2477 * safe to index into page_table[] with it.) */
2478 region_allocation
= page_table
[addr_page_index
].allocated
;
2480 /* quick check 2: Check the offset within the page.
2483 if (((unsigned)addr
& (PAGE_BYTES
- 1)) > page_table
[addr_page_index
].bytes_used
)
2486 /* Filter out anything which can't be a pointer to a Lisp object
2487 * (or, as a special case which also requires dont_move, a return
2488 * address referring to something in a CodeObject). This is
2489 * expensive but important, since it vastly reduces the
2490 * probability that random garbage will be bogusly interpreted as
2491 * a pointer which prevents a page from moving. */
2492 if (!(possibly_valid_dynamic_space_pointer(addr
)))
2495 /* Find the beginning of the region. Note that there may be
2496 * objects in the region preceding the one that we were passed a
2497 * pointer to: if this is the case, we will write-protect all the
2498 * previous objects' pages too. */
2501 /* I think this'd work just as well, but without the assertions.
2502 * -dan 2004.01.01 */
2504 find_page_index(page_address(addr_page_index
)+
2505 page_table
[addr_page_index
].first_object_offset
);
2507 first_page
= addr_page_index
;
2508 while (page_table
[first_page
].first_object_offset
!= 0) {
2510 /* Do some checks. */
2511 gc_assert(page_table
[first_page
].bytes_used
== PAGE_BYTES
);
2512 gc_assert(page_table
[first_page
].gen
== from_space
);
2513 gc_assert(page_table
[first_page
].allocated
== region_allocation
);
2517 /* Adjust any large objects before promotion as they won't be
2518 * copied after promotion. */
2519 if (page_table
[first_page
].large_object
) {
2520 maybe_adjust_large_object(page_address(first_page
));
2521 /* If a large object has shrunk then addr may now point to a
2522 * free area in which case it's ignored here. Note it gets
2523 * through the valid pointer test above because the tail looks
2525 if ((page_table
[addr_page_index
].allocated
== FREE_PAGE_FLAG
)
2526 || (page_table
[addr_page_index
].bytes_used
== 0)
2527 /* Check the offset within the page. */
2528 || (((unsigned)addr
& (PAGE_BYTES
- 1))
2529 > page_table
[addr_page_index
].bytes_used
)) {
2531 "weird? ignore ptr 0x%x to freed area of large object\n",
2535 /* It may have moved to unboxed pages. */
2536 region_allocation
= page_table
[first_page
].allocated
;
2539 /* Now work forward until the end of this contiguous area is found,
2540 * marking all pages as dont_move. */
2541 for (i
= first_page
; ;i
++) {
2542 gc_assert(page_table
[i
].allocated
== region_allocation
);
2544 /* Mark the page static. */
2545 page_table
[i
].dont_move
= 1;
2547 /* Move the page to the new_space. XX I'd rather not do this
2548 * but the GC logic is not quite able to copy with the static
2549 * pages remaining in the from space. This also requires the
2550 * generation bytes_allocated counters be updated. */
2551 page_table
[i
].gen
= new_space
;
2552 generations
[new_space
].bytes_allocated
+= page_table
[i
].bytes_used
;
2553 generations
[from_space
].bytes_allocated
-= page_table
[i
].bytes_used
;
2555 /* It is essential that the pages are not write protected as
2556 * they may have pointers into the old-space which need
2557 * scavenging. They shouldn't be write protected at this
2559 gc_assert(!page_table
[i
].write_protected
);
2561 /* Check whether this is the last page in this contiguous block.. */
2562 if ((page_table
[i
].bytes_used
< PAGE_BYTES
)
2563 /* ..or it is PAGE_BYTES and is the last in the block */
2564 || (page_table
[i
+1].allocated
== FREE_PAGE_FLAG
)
2565 || (page_table
[i
+1].bytes_used
== 0) /* next page free */
2566 || (page_table
[i
+1].gen
!= from_space
) /* diff. gen */
2567 || (page_table
[i
+1].first_object_offset
== 0))
2571 /* Check that the page is now static. */
2572 gc_assert(page_table
[addr_page_index
].dont_move
!= 0);
2575 /* If the given page is not write-protected, then scan it for pointers
2576 * to younger generations or the top temp. generation, if no
2577 * suspicious pointers are found then the page is write-protected.
2579 * Care is taken to check for pointers to the current gc_alloc()
2580 * region if it is a younger generation or the temp. generation. This
2581 * frees the caller from doing a gc_alloc_update_page_tables(). Actually
2582 * the gc_alloc_generation does not need to be checked as this is only
2583 * called from scavenge_generation() when the gc_alloc generation is
2584 * younger, so it just checks if there is a pointer to the current
2587 * We return 1 if the page was write-protected, else 0. */
2589 update_page_write_prot(long page
)
2591 int gen
= page_table
[page
].gen
;
2594 void **page_addr
= (void **)page_address(page
);
2595 long num_words
= page_table
[page
].bytes_used
/ N_WORD_BYTES
;
2597 /* Shouldn't be a free page. */
2598 gc_assert(page_table
[page
].allocated
!= FREE_PAGE_FLAG
);
2599 gc_assert(page_table
[page
].bytes_used
!= 0);
2601 /* Skip if it's already write-protected, pinned, or unboxed */
2602 if (page_table
[page
].write_protected
2603 || page_table
[page
].dont_move
2604 || (page_table
[page
].allocated
& UNBOXED_PAGE_FLAG
))
2607 /* Scan the page for pointers to younger generations or the
2608 * top temp. generation. */
2610 for (j
= 0; j
< num_words
; j
++) {
2611 void *ptr
= *(page_addr
+j
);
2612 long index
= find_page_index(ptr
);
2614 /* Check that it's in the dynamic space */
2616 if (/* Does it point to a younger or the temp. generation? */
2617 ((page_table
[index
].allocated
!= FREE_PAGE_FLAG
)
2618 && (page_table
[index
].bytes_used
!= 0)
2619 && ((page_table
[index
].gen
< gen
)
2620 || (page_table
[index
].gen
== NUM_GENERATIONS
)))
2622 /* Or does it point within a current gc_alloc() region? */
2623 || ((boxed_region
.start_addr
<= ptr
)
2624 && (ptr
<= boxed_region
.free_pointer
))
2625 || ((unboxed_region
.start_addr
<= ptr
)
2626 && (ptr
<= unboxed_region
.free_pointer
))) {
2633 /* Write-protect the page. */
2634 /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
2636 os_protect((void *)page_addr
,
2638 OS_VM_PROT_READ
|OS_VM_PROT_EXECUTE
);
2640 /* Note the page as protected in the page tables. */
2641 page_table
[page
].write_protected
= 1;
2647 /* Scavenge a generation.
2649 * This will not resolve all pointers when generation is the new
2650 * space, as new objects may be added which are not checked here - use
2651 * scavenge_newspace generation.
2653 * Write-protected pages should not have any pointers to the
2654 * from_space so do need scavenging; thus write-protected pages are
2655 * not always scavenged. There is some code to check that these pages
2656 * are not written; but to check fully the write-protected pages need
2657 * to be scavenged by disabling the code to skip them.
2659 * Under the current scheme when a generation is GCed the younger
2660 * generations will be empty. So, when a generation is being GCed it
2661 * is only necessary to scavenge the older generations for pointers
2662 * not the younger. So a page that does not have pointers to younger
2663 * generations does not need to be scavenged.
2665 * The write-protection can be used to note pages that don't have
2666 * pointers to younger pages. But pages can be written without having
2667 * pointers to younger generations. After the pages are scavenged here
2668 * they can be scanned for pointers to younger generations and if
2669 * there are none the page can be write-protected.
2671 * One complication is when the newspace is the top temp. generation.
2673 * Enabling SC_GEN_CK scavenges the write-protected pages and checks
2674 * that none were written, which they shouldn't be as they should have
2675 * no pointers to younger generations. This breaks down for weak
2676 * pointers as the objects contain a link to the next and are written
2677 * if a weak pointer is scavenged. Still it's a useful check. */
2679 scavenge_generation(int generation
)
2686 /* Clear the write_protected_cleared flags on all pages. */
2687 for (i
= 0; i
< NUM_PAGES
; i
++)
2688 page_table
[i
].write_protected_cleared
= 0;
2691 for (i
= 0; i
< last_free_page
; i
++) {
2692 if ((page_table
[i
].allocated
& BOXED_PAGE_FLAG
)
2693 && (page_table
[i
].bytes_used
!= 0)
2694 && (page_table
[i
].gen
== generation
)) {
2696 int write_protected
=1;
2698 /* This should be the start of a region */
2699 gc_assert(page_table
[i
].first_object_offset
== 0);
2701 /* Now work forward until the end of the region */
2702 for (last_page
= i
; ; last_page
++) {
2704 write_protected
&& page_table
[last_page
].write_protected
;
2705 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
2706 /* Or it is PAGE_BYTES and is the last in the block */
2707 || (!(page_table
[last_page
+1].allocated
& BOXED_PAGE_FLAG
))
2708 || (page_table
[last_page
+1].bytes_used
== 0)
2709 || (page_table
[last_page
+1].gen
!= generation
)
2710 || (page_table
[last_page
+1].first_object_offset
== 0))
2713 if (!write_protected
) {
2714 scavenge(page_address(i
),
2715 (page_table
[last_page
].bytes_used
+
2716 (last_page
-i
)*PAGE_BYTES
)/N_WORD_BYTES
);
2718 /* Now scan the pages and write protect those that
2719 * don't have pointers to younger generations. */
2720 if (enable_page_protection
) {
2721 for (j
= i
; j
<= last_page
; j
++) {
2722 num_wp
+= update_page_write_prot(j
);
2729 if ((gencgc_verbose
> 1) && (num_wp
!= 0)) {
2731 "/write protected %d pages within generation %d\n",
2732 num_wp
, generation
));
2736 /* Check that none of the write_protected pages in this generation
2737 * have been written to. */
2738 for (i
= 0; i
< NUM_PAGES
; i
++) {
2739 if ((page_table
[i
].allocation
!= FREE_PAGE_FLAG
)
2740 && (page_table
[i
].bytes_used
!= 0)
2741 && (page_table
[i
].gen
== generation
)
2742 && (page_table
[i
].write_protected_cleared
!= 0)) {
2743 FSHOW((stderr
, "/scavenge_generation() %d\n", generation
));
2745 "/page bytes_used=%d first_object_offset=%d dont_move=%d\n",
2746 page_table
[i
].bytes_used
,
2747 page_table
[i
].first_object_offset
,
2748 page_table
[i
].dont_move
));
2749 lose("write to protected page %d in scavenge_generation()", i
);
2756 /* Scavenge a newspace generation. As it is scavenged new objects may
2757 * be allocated to it; these will also need to be scavenged. This
2758 * repeats until there are no more objects unscavenged in the
2759 * newspace generation.
2761 * To help improve the efficiency, areas written are recorded by
2762 * gc_alloc() and only these scavenged. Sometimes a little more will be
2763 * scavenged, but this causes no harm. An easy check is done that the
2764 * scavenged bytes equals the number allocated in the previous
2767 * Write-protected pages are not scanned except if they are marked
2768 * dont_move in which case they may have been promoted and still have
2769 * pointers to the from space.
2771 * Write-protected pages could potentially be written by alloc however
2772 * to avoid having to handle re-scavenging of write-protected pages
2773 * gc_alloc() does not write to write-protected pages.
2775 * New areas of objects allocated are recorded alternatively in the two
2776 * new_areas arrays below. */
2777 static struct new_area new_areas_1
[NUM_NEW_AREAS
];
2778 static struct new_area new_areas_2
[NUM_NEW_AREAS
];
2780 /* Do one full scan of the new space generation. This is not enough to
2781 * complete the job as new objects may be added to the generation in
2782 * the process which are not scavenged. */
2784 scavenge_newspace_generation_one_scan(int generation
)
2789 "/starting one full scan of newspace generation %d\n",
2791 for (i
= 0; i
< last_free_page
; i
++) {
2792 /* Note that this skips over open regions when it encounters them. */
2793 if ((page_table
[i
].allocated
& BOXED_PAGE_FLAG
)
2794 && (page_table
[i
].bytes_used
!= 0)
2795 && (page_table
[i
].gen
== generation
)
2796 && ((page_table
[i
].write_protected
== 0)
2797 /* (This may be redundant as write_protected is now
2798 * cleared before promotion.) */
2799 || (page_table
[i
].dont_move
== 1))) {
2803 /* The scavenge will start at the first_object_offset of page i.
2805 * We need to find the full extent of this contiguous
2806 * block in case objects span pages.
2808 * Now work forward until the end of this contiguous area
2809 * is found. A small area is preferred as there is a
2810 * better chance of its pages being write-protected. */
2811 for (last_page
= i
; ;last_page
++) {
2812 /* If all pages are write-protected and movable,
2813 * then no need to scavenge */
2814 all_wp
=all_wp
&& page_table
[last_page
].write_protected
&&
2815 !page_table
[last_page
].dont_move
;
2817 /* Check whether this is the last page in this
2818 * contiguous block */
2819 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
2820 /* Or it is PAGE_BYTES and is the last in the block */
2821 || (!(page_table
[last_page
+1].allocated
& BOXED_PAGE_FLAG
))
2822 || (page_table
[last_page
+1].bytes_used
== 0)
2823 || (page_table
[last_page
+1].gen
!= generation
)
2824 || (page_table
[last_page
+1].first_object_offset
== 0))
2828 /* Do a limited check for write-protected pages. */
2832 size
= (page_table
[last_page
].bytes_used
2833 + (last_page
-i
)*PAGE_BYTES
2834 - page_table
[i
].first_object_offset
)/N_WORD_BYTES
;
2835 new_areas_ignore_page
= last_page
;
2837 scavenge(page_address(i
) +
2838 page_table
[i
].first_object_offset
,
2846 "/done with one full scan of newspace generation %d\n",
2850 /* Do a complete scavenge of the newspace generation. */
2852 scavenge_newspace_generation(int generation
)
2856 /* the new_areas array currently being written to by gc_alloc() */
2857 struct new_area (*current_new_areas
)[] = &new_areas_1
;
2858 long current_new_areas_index
;
2860 /* the new_areas created by the previous scavenge cycle */
2861 struct new_area (*previous_new_areas
)[] = NULL
;
2862 long previous_new_areas_index
;
2864 /* Flush the current regions updating the tables. */
2865 gc_alloc_update_all_page_tables();
2867 /* Turn on the recording of new areas by gc_alloc(). */
2868 new_areas
= current_new_areas
;
2869 new_areas_index
= 0;
2871 /* Don't need to record new areas that get scavenged anyway during
2872 * scavenge_newspace_generation_one_scan. */
2873 record_new_objects
= 1;
2875 /* Start with a full scavenge. */
2876 scavenge_newspace_generation_one_scan(generation
);
2878 /* Record all new areas now. */
2879 record_new_objects
= 2;
2881 /* Flush the current regions updating the tables. */
2882 gc_alloc_update_all_page_tables();
2884 /* Grab new_areas_index. */
2885 current_new_areas_index
= new_areas_index
;
2888 "The first scan is finished; current_new_areas_index=%d.\n",
2889 current_new_areas_index));*/
2891 while (current_new_areas_index
> 0) {
2892 /* Move the current to the previous new areas */
2893 previous_new_areas
= current_new_areas
;
2894 previous_new_areas_index
= current_new_areas_index
;
2896 /* Scavenge all the areas in previous new areas. Any new areas
2897 * allocated are saved in current_new_areas. */
2899 /* Allocate an array for current_new_areas; alternating between
2900 * new_areas_1 and 2 */
2901 if (previous_new_areas
== &new_areas_1
)
2902 current_new_areas
= &new_areas_2
;
2904 current_new_areas
= &new_areas_1
;
2906 /* Set up for gc_alloc(). */
2907 new_areas
= current_new_areas
;
2908 new_areas_index
= 0;
2910 /* Check whether previous_new_areas had overflowed. */
2911 if (previous_new_areas_index
>= NUM_NEW_AREAS
) {
2913 /* New areas of objects allocated have been lost so need to do a
2914 * full scan to be sure! If this becomes a problem try
2915 * increasing NUM_NEW_AREAS. */
2917 SHOW("new_areas overflow, doing full scavenge");
2919 /* Don't need to record new areas that get scavenge anyway
2920 * during scavenge_newspace_generation_one_scan. */
2921 record_new_objects
= 1;
2923 scavenge_newspace_generation_one_scan(generation
);
2925 /* Record all new areas now. */
2926 record_new_objects
= 2;
2928 /* Flush the current regions updating the tables. */
2929 gc_alloc_update_all_page_tables();
2933 /* Work through previous_new_areas. */
2934 for (i
= 0; i
< previous_new_areas_index
; i
++) {
2935 long page
= (*previous_new_areas
)[i
].page
;
2936 long offset
= (*previous_new_areas
)[i
].offset
;
2937 long size
= (*previous_new_areas
)[i
].size
/ N_WORD_BYTES
;
2938 gc_assert((*previous_new_areas
)[i
].size
% N_WORD_BYTES
== 0);
2939 scavenge(page_address(page
)+offset
, size
);
2942 /* Flush the current regions updating the tables. */
2943 gc_alloc_update_all_page_tables();
2946 current_new_areas_index
= new_areas_index
;
2949 "The re-scan has finished; current_new_areas_index=%d.\n",
2950 current_new_areas_index));*/
2953 /* Turn off recording of areas allocated by gc_alloc(). */
2954 record_new_objects
= 0;
2957 /* Check that none of the write_protected pages in this generation
2958 * have been written to. */
2959 for (i
= 0; i
< NUM_PAGES
; i
++) {
2960 if ((page_table
[i
].allocation
!= FREE_PAGE_FLAG
)
2961 && (page_table
[i
].bytes_used
!= 0)
2962 && (page_table
[i
].gen
== generation
)
2963 && (page_table
[i
].write_protected_cleared
!= 0)
2964 && (page_table
[i
].dont_move
== 0)) {
2965 lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d",
2966 i
, generation
, page_table
[i
].dont_move
);
2972 /* Un-write-protect all the pages in from_space. This is done at the
2973 * start of a GC else there may be many page faults while scavenging
2974 * the newspace (I've seen drive the system time to 99%). These pages
2975 * would need to be unprotected anyway before unmapping in
2976 * free_oldspace; not sure what effect this has on paging.. */
2978 unprotect_oldspace(void)
2982 for (i
= 0; i
< last_free_page
; i
++) {
2983 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
2984 && (page_table
[i
].bytes_used
!= 0)
2985 && (page_table
[i
].gen
== from_space
)) {
2988 page_start
= (void *)page_address(i
);
2990 /* Remove any write-protection. We should be able to rely
2991 * on the write-protect flag to avoid redundant calls. */
2992 if (page_table
[i
].write_protected
) {
2993 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
2994 page_table
[i
].write_protected
= 0;
3000 /* Work through all the pages and free any in from_space. This
3001 * assumes that all objects have been copied or promoted to an older
3002 * generation. Bytes_allocated and the generation bytes_allocated
3003 * counter are updated. The number of bytes freed is returned. */
3007 long bytes_freed
= 0;
3008 long first_page
, last_page
;
3013 /* Find a first page for the next region of pages. */
3014 while ((first_page
< last_free_page
)
3015 && ((page_table
[first_page
].allocated
== FREE_PAGE_FLAG
)
3016 || (page_table
[first_page
].bytes_used
== 0)
3017 || (page_table
[first_page
].gen
!= from_space
)))
3020 if (first_page
>= last_free_page
)
3023 /* Find the last page of this region. */
3024 last_page
= first_page
;
3027 /* Free the page. */
3028 bytes_freed
+= page_table
[last_page
].bytes_used
;
3029 generations
[page_table
[last_page
].gen
].bytes_allocated
-=
3030 page_table
[last_page
].bytes_used
;
3031 page_table
[last_page
].allocated
= FREE_PAGE_FLAG
;
3032 page_table
[last_page
].bytes_used
= 0;
3034 /* Remove any write-protection. We should be able to rely
3035 * on the write-protect flag to avoid redundant calls. */
3037 void *page_start
= (void *)page_address(last_page
);
3039 if (page_table
[last_page
].write_protected
) {
3040 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
3041 page_table
[last_page
].write_protected
= 0;
3046 while ((last_page
< last_free_page
)
3047 && (page_table
[last_page
].allocated
!= FREE_PAGE_FLAG
)
3048 && (page_table
[last_page
].bytes_used
!= 0)
3049 && (page_table
[last_page
].gen
== from_space
));
3051 /* Zero pages from first_page to (last_page-1).
3053 * FIXME: Why not use os_zero(..) function instead of
3054 * hand-coding this again? (Check other gencgc_unmap_zero
3056 if (gencgc_unmap_zero
) {
3057 void *page_start
, *addr
;
3059 page_start
= (void *)page_address(first_page
);
3061 os_invalidate(page_start
, PAGE_BYTES
*(last_page
-first_page
));
3062 addr
= os_validate(page_start
, PAGE_BYTES
*(last_page
-first_page
));
3063 if (addr
== NULL
|| addr
!= page_start
) {
3064 lose("free_oldspace: page moved, 0x%08x ==> 0x%08x",page_start
,
3070 page_start
= (long *)page_address(first_page
);
3071 memset(page_start
, 0,PAGE_BYTES
*(last_page
-first_page
));
3074 first_page
= last_page
;
3076 } while (first_page
< last_free_page
);
3078 bytes_allocated
-= bytes_freed
;
3083 /* Print some information about a pointer at the given address. */
3085 print_ptr(lispobj
*addr
)
3087 /* If addr is in the dynamic space then out the page information. */
3088 long pi1
= find_page_index((void*)addr
);
3091 fprintf(stderr
," %x: page %d alloc %d gen %d bytes_used %d offset %d dont_move %d\n",
3092 (unsigned long) addr
,
3094 page_table
[pi1
].allocated
,
3095 page_table
[pi1
].gen
,
3096 page_table
[pi1
].bytes_used
,
3097 page_table
[pi1
].first_object_offset
,
3098 page_table
[pi1
].dont_move
);
3099 fprintf(stderr
," %x %x %x %x (%x) %x %x %x %x\n",
3112 extern long undefined_tramp
;
3115 verify_space(lispobj
*start
, size_t words
)
3117 int is_in_dynamic_space
= (find_page_index((void*)start
) != -1);
3118 int is_in_readonly_space
=
3119 (READ_ONLY_SPACE_START
<= (unsigned)start
&&
3120 (unsigned)start
< SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0));
3124 lispobj thing
= *(lispobj
*)start
;
3126 if (is_lisp_pointer(thing
)) {
3127 long page_index
= find_page_index((void*)thing
);
3128 long to_readonly_space
=
3129 (READ_ONLY_SPACE_START
<= thing
&&
3130 thing
< SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0));
3131 long to_static_space
=
3132 (STATIC_SPACE_START
<= thing
&&
3133 thing
< SymbolValue(STATIC_SPACE_FREE_POINTER
,0));
3135 /* Does it point to the dynamic space? */
3136 if (page_index
!= -1) {
3137 /* If it's within the dynamic space it should point to a used
3138 * page. XX Could check the offset too. */
3139 if ((page_table
[page_index
].allocated
!= FREE_PAGE_FLAG
)
3140 && (page_table
[page_index
].bytes_used
== 0))
3141 lose ("Ptr %x @ %x sees free page.", thing
, start
);
3142 /* Check that it doesn't point to a forwarding pointer! */
3143 if (*((lispobj
*)native_pointer(thing
)) == 0x01) {
3144 lose("Ptr %x @ %x sees forwarding ptr.", thing
, start
);
3146 /* Check that its not in the RO space as it would then be a
3147 * pointer from the RO to the dynamic space. */
3148 if (is_in_readonly_space
) {
3149 lose("ptr to dynamic space %x from RO space %x",
3152 /* Does it point to a plausible object? This check slows
3153 * it down a lot (so it's commented out).
3155 * "a lot" is serious: it ate 50 minutes cpu time on
3156 * my duron 950 before I came back from lunch and
3159 * FIXME: Add a variable to enable this
3162 if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
3163 lose("ptr %x to invalid object %x", thing, start);
3167 /* Verify that it points to another valid space. */
3168 if (!to_readonly_space
&& !to_static_space
3169 && (thing
!= (unsigned)&undefined_tramp
)) {
3170 lose("Ptr %x @ %x sees junk.", thing
, start
);
3174 if (!(fixnump(thing
))) {
3176 switch(widetag_of(*start
)) {
3179 case SIMPLE_VECTOR_WIDETAG
:
3181 case COMPLEX_WIDETAG
:
3182 case SIMPLE_ARRAY_WIDETAG
:
3183 case COMPLEX_BASE_STRING_WIDETAG
:
3184 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
3185 case COMPLEX_CHARACTER_STRING_WIDETAG
:
3187 case COMPLEX_VECTOR_NIL_WIDETAG
:
3188 case COMPLEX_BIT_VECTOR_WIDETAG
:
3189 case COMPLEX_VECTOR_WIDETAG
:
3190 case COMPLEX_ARRAY_WIDETAG
:
3191 case CLOSURE_HEADER_WIDETAG
:
3192 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG
:
3193 case VALUE_CELL_HEADER_WIDETAG
:
3194 case SYMBOL_HEADER_WIDETAG
:
3195 case CHARACTER_WIDETAG
:
3196 #if N_WORD_BITS == 64
3197 case SINGLE_FLOAT_WIDETAG
:
3199 case UNBOUND_MARKER_WIDETAG
:
3200 case INSTANCE_HEADER_WIDETAG
:
3205 case CODE_HEADER_WIDETAG
:
3207 lispobj object
= *start
;
3209 long nheader_words
, ncode_words
, nwords
;
3211 struct simple_fun
*fheaderp
;
3213 code
= (struct code
*) start
;
3215 /* Check that it's not in the dynamic space.
3216 * FIXME: Isn't is supposed to be OK for code
3217 * objects to be in the dynamic space these days? */
3218 if (is_in_dynamic_space
3219 /* It's ok if it's byte compiled code. The trace
3220 * table offset will be a fixnum if it's x86
3221 * compiled code - check.
3223 * FIXME: #^#@@! lack of abstraction here..
3224 * This line can probably go away now that
3225 * there's no byte compiler, but I've got
3226 * too much to worry about right now to try
3227 * to make sure. -- WHN 2001-10-06 */
3228 && fixnump(code
->trace_table_offset
)
3229 /* Only when enabled */
3230 && verify_dynamic_code_check
) {
3232 "/code object at %x in the dynamic space\n",
3236 ncode_words
= fixnum_value(code
->code_size
);
3237 nheader_words
= HeaderValue(object
);
3238 nwords
= ncode_words
+ nheader_words
;
3239 nwords
= CEILING(nwords
, 2);
3240 /* Scavenge the boxed section of the code data block */
3241 verify_space(start
+ 1, nheader_words
- 1);
3243 /* Scavenge the boxed section of each function
3244 * object in the code data block. */
3245 fheaderl
= code
->entry_points
;
3246 while (fheaderl
!= NIL
) {
3248 (struct simple_fun
*) native_pointer(fheaderl
);
3249 gc_assert(widetag_of(fheaderp
->header
) == SIMPLE_FUN_HEADER_WIDETAG
);
3250 verify_space(&fheaderp
->name
, 1);
3251 verify_space(&fheaderp
->arglist
, 1);
3252 verify_space(&fheaderp
->type
, 1);
3253 fheaderl
= fheaderp
->next
;
3259 /* unboxed objects */
3260 case BIGNUM_WIDETAG
:
3261 #if N_WORD_BITS != 64
3262 case SINGLE_FLOAT_WIDETAG
:
3264 case DOUBLE_FLOAT_WIDETAG
:
3265 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3266 case LONG_FLOAT_WIDETAG
:
3268 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3269 case COMPLEX_SINGLE_FLOAT_WIDETAG
:
3271 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3272 case COMPLEX_DOUBLE_FLOAT_WIDETAG
:
3274 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3275 case COMPLEX_LONG_FLOAT_WIDETAG
:
3277 case SIMPLE_BASE_STRING_WIDETAG
:
3278 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
3279 case SIMPLE_CHARACTER_STRING_WIDETAG
:
3281 case SIMPLE_BIT_VECTOR_WIDETAG
:
3282 case SIMPLE_ARRAY_NIL_WIDETAG
:
3283 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG
:
3284 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG
:
3285 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG
:
3286 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG
:
3287 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG
:
3288 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG
:
3289 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
3290 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
:
3292 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG
:
3293 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
:
3294 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
3295 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
:
3297 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
3298 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
:
3300 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
3301 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
:
3303 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3304 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
:
3306 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3307 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
:
3309 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3310 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
:
3312 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3313 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
:
3315 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
3316 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
:
3318 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
3319 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
:
3321 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG
:
3322 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG
:
3323 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3324 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
:
3326 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3327 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
:
3329 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3330 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
:
3332 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3333 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
:
3336 case WEAK_POINTER_WIDETAG
:
3337 count
= (sizetab
[widetag_of(*start
)])(start
);
3353 /* FIXME: It would be nice to make names consistent so that
3354 * foo_size meant size *in* *bytes* instead of size in some
3355 * arbitrary units. (Yes, this caused a bug, how did you guess?:-)
3356 * Some counts of lispobjs are called foo_count; it might be good
3357 * to grep for all foo_size and rename the appropriate ones to
3359 long read_only_space_size
=
3360 (lispobj
*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER
,0)
3361 - (lispobj
*)READ_ONLY_SPACE_START
;
3362 long static_space_size
=
3363 (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0)
3364 - (lispobj
*)STATIC_SPACE_START
;
3366 for_each_thread(th
) {
3367 long binding_stack_size
=
3368 (lispobj
*)SymbolValue(BINDING_STACK_POINTER
,th
)
3369 - (lispobj
*)th
->binding_stack_start
;
3370 verify_space(th
->binding_stack_start
, binding_stack_size
);
3372 verify_space((lispobj
*)READ_ONLY_SPACE_START
, read_only_space_size
);
3373 verify_space((lispobj
*)STATIC_SPACE_START
, static_space_size
);
3377 verify_generation(int generation
)
3381 for (i
= 0; i
< last_free_page
; i
++) {
3382 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
3383 && (page_table
[i
].bytes_used
!= 0)
3384 && (page_table
[i
].gen
== generation
)) {
3386 int region_allocation
= page_table
[i
].allocated
;
3388 /* This should be the start of a contiguous block */
3389 gc_assert(page_table
[i
].first_object_offset
== 0);
3391 /* Need to find the full extent of this contiguous block in case
3392 objects span pages. */
3394 /* Now work forward until the end of this contiguous area is
3396 for (last_page
= i
; ;last_page
++)
3397 /* Check whether this is the last page in this contiguous
3399 if ((page_table
[last_page
].bytes_used
< PAGE_BYTES
)
3400 /* Or it is PAGE_BYTES and is the last in the block */
3401 || (page_table
[last_page
+1].allocated
!= region_allocation
)
3402 || (page_table
[last_page
+1].bytes_used
== 0)
3403 || (page_table
[last_page
+1].gen
!= generation
)
3404 || (page_table
[last_page
+1].first_object_offset
== 0))
3407 verify_space(page_address(i
), (page_table
[last_page
].bytes_used
3408 + (last_page
-i
)*PAGE_BYTES
)/N_WORD_BYTES
);
3414 /* Check that all the free space is zero filled. */
3416 verify_zero_fill(void)
3420 for (page
= 0; page
< last_free_page
; page
++) {
3421 if (page_table
[page
].allocated
== FREE_PAGE_FLAG
) {
3422 /* The whole page should be zero filled. */
3423 long *start_addr
= (long *)page_address(page
);
3426 for (i
= 0; i
< size
; i
++) {
3427 if (start_addr
[i
] != 0) {
3428 lose("free page not zero at %x", start_addr
+ i
);
3432 long free_bytes
= PAGE_BYTES
- page_table
[page
].bytes_used
;
3433 if (free_bytes
> 0) {
3434 long *start_addr
= (long *)((unsigned)page_address(page
)
3435 + page_table
[page
].bytes_used
);
3436 long size
= free_bytes
/ N_WORD_BYTES
;
3438 for (i
= 0; i
< size
; i
++) {
3439 if (start_addr
[i
] != 0) {
3440 lose("free region not zero at %x", start_addr
+ i
);
3448 /* External entry point for verify_zero_fill */
3450 gencgc_verify_zero_fill(void)
3452 /* Flush the alloc regions updating the tables. */
3453 gc_alloc_update_all_page_tables();
3454 SHOW("verifying zero fill");
3459 verify_dynamic_space(void)
3463 for (i
= 0; i
< NUM_GENERATIONS
; i
++)
3464 verify_generation(i
);
3466 if (gencgc_enable_verify_zero_fill
)
3470 /* Write-protect all the dynamic boxed pages in the given generation. */
3472 write_protect_generation_pages(int generation
)
3476 gc_assert(generation
< NUM_GENERATIONS
);
3478 for (i
= 0; i
< last_free_page
; i
++)
3479 if ((page_table
[i
].allocated
== BOXED_PAGE_FLAG
)
3480 && (page_table
[i
].bytes_used
!= 0)
3481 && !page_table
[i
].dont_move
3482 && (page_table
[i
].gen
== generation
)) {
3485 page_start
= (void *)page_address(i
);
3487 os_protect(page_start
,
3489 OS_VM_PROT_READ
| OS_VM_PROT_EXECUTE
);
3491 /* Note the page as protected in the page tables. */
3492 page_table
[i
].write_protected
= 1;
3495 if (gencgc_verbose
> 1) {
3497 "/write protected %d of %d pages in generation %d\n",
3498 count_write_protect_generation_pages(generation
),
3499 count_generation_pages(generation
),
3504 /* Garbage collect a generation. If raise is 0 then the remains of the
3505 * generation are not raised to the next generation. */
3507 garbage_collect_generation(int generation
, int raise
)
3509 unsigned long bytes_freed
;
3511 unsigned long static_space_size
;
3513 gc_assert(generation
<= (NUM_GENERATIONS
-1));
3515 /* The oldest generation can't be raised. */
3516 gc_assert((generation
!= (NUM_GENERATIONS
-1)) || (raise
== 0));
3518 /* Initialize the weak pointer list. */
3519 weak_pointers
= NULL
;
3521 /* When a generation is not being raised it is transported to a
3522 * temporary generation (NUM_GENERATIONS), and lowered when
3523 * done. Set up this new generation. There should be no pages
3524 * allocated to it yet. */
3526 gc_assert(generations
[NUM_GENERATIONS
].bytes_allocated
== 0);
3529 /* Set the global src and dest. generations */
3530 from_space
= generation
;
3532 new_space
= generation
+1;
3534 new_space
= NUM_GENERATIONS
;
3536 /* Change to a new space for allocation, resetting the alloc_start_page */
3537 gc_alloc_generation
= new_space
;
3538 generations
[new_space
].alloc_start_page
= 0;
3539 generations
[new_space
].alloc_unboxed_start_page
= 0;
3540 generations
[new_space
].alloc_large_start_page
= 0;
3541 generations
[new_space
].alloc_large_unboxed_start_page
= 0;
3543 /* Before any pointers are preserved, the dont_move flags on the
3544 * pages need to be cleared. */
3545 for (i
= 0; i
< last_free_page
; i
++)
3546 if(page_table
[i
].gen
==from_space
)
3547 page_table
[i
].dont_move
= 0;
3549 /* Un-write-protect the old-space pages. This is essential for the
3550 * promoted pages as they may contain pointers into the old-space
3551 * which need to be scavenged. It also helps avoid unnecessary page
3552 * faults as forwarding pointers are written into them. They need to
3553 * be un-protected anyway before unmapping later. */
3554 unprotect_oldspace();
3556 /* Scavenge the stacks' conservative roots. */
3558 /* there are potentially two stacks for each thread: the main
3559 * stack, which may contain Lisp pointers, and the alternate stack.
3560 * We don't ever run Lisp code on the altstack, but it may
3561 * host a sigcontext with lisp objects in it */
3563 /* what we need to do: (1) find the stack pointer for the main
3564 * stack; scavenge it (2) find the interrupt context on the
3565 * alternate stack that might contain lisp values, and scavenge
3568 /* we assume that none of the preceding applies to the thread that
3569 * initiates GC. If you ever call GC from inside an altstack
3570 * handler, you will lose. */
3571 for_each_thread(th
) {
3573 void **esp
=(void **)-1;
3574 #ifdef LISP_FEATURE_SB_THREAD
3576 if(th
==arch_os_get_current_thread()) {
3577 esp
= (void **) &raise
;
3580 free
=fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX
,th
));
3581 for(i
=free
-1;i
>=0;i
--) {
3582 os_context_t
*c
=th
->interrupt_contexts
[i
];
3583 esp1
= (void **) *os_context_register_addr(c
,reg_SP
);
3584 if(esp1
>=th
->control_stack_start
&& esp1
<th
->control_stack_end
){
3585 if(esp1
<esp
) esp
=esp1
;
3586 for(ptr
= (void **)(c
+1); ptr
>=(void **)c
; ptr
--) {
3587 preserve_pointer(*ptr
);
3593 esp
= (void **) &raise
;
3595 for (ptr
= (void **)th
->control_stack_end
; ptr
> esp
; ptr
--) {
3596 preserve_pointer(*ptr
);
3601 if (gencgc_verbose
> 1) {
3602 long num_dont_move_pages
= count_dont_move_pages();
3604 "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
3605 num_dont_move_pages
,
3606 num_dont_move_pages
* PAGE_BYTES
);
3610 /* Scavenge all the rest of the roots. */
3612 /* Scavenge the Lisp functions of the interrupt handlers, taking
3613 * care to avoid SIG_DFL and SIG_IGN. */
3614 for_each_thread(th
) {
3615 struct interrupt_data
*data
=th
->interrupt_data
;
3616 for (i
= 0; i
< NSIG
; i
++) {
3617 union interrupt_handler handler
= data
->interrupt_handlers
[i
];
3618 if (!ARE_SAME_HANDLER(handler
.c
, SIG_IGN
) &&
3619 !ARE_SAME_HANDLER(handler
.c
, SIG_DFL
)) {
3620 scavenge((lispobj
*)(data
->interrupt_handlers
+ i
), 1);
3624 /* Scavenge the binding stacks. */
3627 for_each_thread(th
) {
3628 long len
= (lispobj
*)SymbolValue(BINDING_STACK_POINTER
,th
) -
3629 th
->binding_stack_start
;
3630 scavenge((lispobj
*) th
->binding_stack_start
,len
);
3631 #ifdef LISP_FEATURE_SB_THREAD
3632 /* do the tls as well */
3633 len
=fixnum_value(SymbolValue(FREE_TLS_INDEX
,0)) -
3634 (sizeof (struct thread
))/(sizeof (lispobj
));
3635 scavenge((lispobj
*) (th
+1),len
);
3640 /* The original CMU CL code had scavenge-read-only-space code
3641 * controlled by the Lisp-level variable
3642 * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
3643 * wasn't documented under what circumstances it was useful or
3644 * safe to turn it on, so it's been turned off in SBCL. If you
3645 * want/need this functionality, and can test and document it,
3646 * please submit a patch. */
3648 if (SymbolValue(SCAVENGE_READ_ONLY_SPACE
) != NIL
) {
3649 unsigned long read_only_space_size
=
3650 (lispobj
*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER
) -
3651 (lispobj
*)READ_ONLY_SPACE_START
;
3653 "/scavenge read only space: %d bytes\n",
3654 read_only_space_size
* sizeof(lispobj
)));
3655 scavenge( (lispobj
*) READ_ONLY_SPACE_START
, read_only_space_size
);
3659 /* Scavenge static space. */
3661 (lispobj
*)SymbolValue(STATIC_SPACE_FREE_POINTER
,0) -
3662 (lispobj
*)STATIC_SPACE_START
;
3663 if (gencgc_verbose
> 1) {
3665 "/scavenge static space: %d bytes\n",
3666 static_space_size
* sizeof(lispobj
)));
3668 scavenge( (lispobj
*) STATIC_SPACE_START
, static_space_size
);
3670 /* All generations but the generation being GCed need to be
3671 * scavenged. The new_space generation needs special handling as
3672 * objects may be moved in - it is handled separately below. */
3673 for (i
= 0; i
< NUM_GENERATIONS
; i
++) {
3674 if ((i
!= generation
) && (i
!= new_space
)) {
3675 scavenge_generation(i
);
3679 /* Finally scavenge the new_space generation. Keep going until no
3680 * more objects are moved into the new generation */
3681 scavenge_newspace_generation(new_space
);
3683 /* FIXME: I tried reenabling this check when debugging unrelated
3684 * GC weirdness ca. sbcl-0.6.12.45, and it failed immediately.
3685 * Since the current GC code seems to work well, I'm guessing that
3686 * this debugging code is just stale, but I haven't tried to
3687 * figure it out. It should be figured out and then either made to
3688 * work or just deleted. */
3689 #define RESCAN_CHECK 0
3691 /* As a check re-scavenge the newspace once; no new objects should
3694 long old_bytes_allocated
= bytes_allocated
;
3695 long bytes_allocated
;
3697 /* Start with a full scavenge. */
3698 scavenge_newspace_generation_one_scan(new_space
);
3700 /* Flush the current regions, updating the tables. */
3701 gc_alloc_update_all_page_tables();
3703 bytes_allocated
= bytes_allocated
- old_bytes_allocated
;
3705 if (bytes_allocated
!= 0) {
3706 lose("Rescan of new_space allocated %d more bytes.",
3712 scan_weak_pointers();
3714 /* Flush the current regions, updating the tables. */
3715 gc_alloc_update_all_page_tables();
3717 /* Free the pages in oldspace, but not those marked dont_move. */
3718 bytes_freed
= free_oldspace();
3720 /* If the GC is not raising the age then lower the generation back
3721 * to its normal generation number */
3723 for (i
= 0; i
< last_free_page
; i
++)
3724 if ((page_table
[i
].bytes_used
!= 0)
3725 && (page_table
[i
].gen
== NUM_GENERATIONS
))
3726 page_table
[i
].gen
= generation
;
3727 gc_assert(generations
[generation
].bytes_allocated
== 0);
3728 generations
[generation
].bytes_allocated
=
3729 generations
[NUM_GENERATIONS
].bytes_allocated
;
3730 generations
[NUM_GENERATIONS
].bytes_allocated
= 0;
3733 /* Reset the alloc_start_page for generation. */
3734 generations
[generation
].alloc_start_page
= 0;
3735 generations
[generation
].alloc_unboxed_start_page
= 0;
3736 generations
[generation
].alloc_large_start_page
= 0;
3737 generations
[generation
].alloc_large_unboxed_start_page
= 0;
3739 if (generation
>= verify_gens
) {
3743 verify_dynamic_space();
3746 /* Set the new gc trigger for the GCed generation. */
3747 generations
[generation
].gc_trigger
=
3748 generations
[generation
].bytes_allocated
3749 + generations
[generation
].bytes_consed_between_gc
;
3752 generations
[generation
].num_gc
= 0;
3754 ++generations
[generation
].num_gc
;
3757 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
3759 update_x86_dynamic_space_free_pointer(void)
3761 long last_page
= -1;
3764 for (i
= 0; i
< last_free_page
; i
++)
3765 if ((page_table
[i
].allocated
!= FREE_PAGE_FLAG
)
3766 && (page_table
[i
].bytes_used
!= 0))
3769 last_free_page
= last_page
+1;
3771 SetSymbolValue(ALLOCATION_POINTER
,
3772 (lispobj
)(((char *)heap_base
) + last_free_page
*PAGE_BYTES
),0);
3773 return 0; /* dummy value: return something ... */
3776 /* GC all generations newer than last_gen, raising the objects in each
3777 * to the next older generation - we finish when all generations below
3778 * last_gen are empty. Then if last_gen is due for a GC, or if
3779 * last_gen==NUM_GENERATIONS (the scratch generation? eh?) we GC that
3780 * too. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
3782 * We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
3783 * last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
3786 collect_garbage(unsigned last_gen
)
3793 FSHOW((stderr
, "/entering collect_garbage(%d)\n", last_gen
));
3795 if (last_gen
> NUM_GENERATIONS
) {
3797 "/collect_garbage: last_gen = %d, doing a level 0 GC\n",
3802 /* Flush the alloc regions updating the tables. */
3803 gc_alloc_update_all_page_tables();
3805 /* Verify the new objects created by Lisp code. */
3806 if (pre_verify_gen_0
) {
3807 FSHOW((stderr
, "pre-checking generation 0\n"));
3808 verify_generation(0);
3811 if (gencgc_verbose
> 1)
3812 print_generation_stats(0);
3815 /* Collect the generation. */
3817 if (gen
>= gencgc_oldest_gen_to_gc
) {
3818 /* Never raise the oldest generation. */
3823 || (generations
[gen
].num_gc
>= generations
[gen
].trigger_age
);
3826 if (gencgc_verbose
> 1) {
3828 "starting GC of generation %d with raise=%d alloc=%d trig=%d GCs=%d\n",
3831 generations
[gen
].bytes_allocated
,
3832 generations
[gen
].gc_trigger
,
3833 generations
[gen
].num_gc
));
3836 /* If an older generation is being filled, then update its
3839 generations
[gen
+1].cum_sum_bytes_allocated
+=
3840 generations
[gen
+1].bytes_allocated
;
3843 garbage_collect_generation(gen
, raise
);
3845 /* Reset the memory age cum_sum. */
3846 generations
[gen
].cum_sum_bytes_allocated
= 0;
3848 if (gencgc_verbose
> 1) {
3849 FSHOW((stderr
, "GC of generation %d finished:\n", gen
));
3850 print_generation_stats(0);
3854 } while ((gen
<= gencgc_oldest_gen_to_gc
)
3855 && ((gen
< last_gen
)
3856 || ((gen
<= gencgc_oldest_gen_to_gc
)
3858 && (generations
[gen
].bytes_allocated
3859 > generations
[gen
].gc_trigger
)
3860 && (gen_av_mem_age(gen
)
3861 > generations
[gen
].min_av_mem_age
))));
3863 /* Now if gen-1 was raised all generations before gen are empty.
3864 * If it wasn't raised then all generations before gen-1 are empty.
3866 * Now objects within this gen's pages cannot point to younger
3867 * generations unless they are written to. This can be exploited
3868 * by write-protecting the pages of gen; then when younger
3869 * generations are GCed only the pages which have been written
3874 gen_to_wp
= gen
- 1;
3876 /* There's not much point in WPing pages in generation 0 as it is
3877 * never scavenged (except promoted pages). */
3878 if ((gen_to_wp
> 0) && enable_page_protection
) {
3879 /* Check that they are all empty. */
3880 for (i
= 0; i
< gen_to_wp
; i
++) {
3881 if (generations
[i
].bytes_allocated
)
3882 lose("trying to write-protect gen. %d when gen. %d nonempty",
3885 write_protect_generation_pages(gen_to_wp
);
3888 /* Set gc_alloc() back to generation 0. The current regions should
3889 * be flushed after the above GCs. */
3890 gc_assert((boxed_region
.free_pointer
- boxed_region
.start_addr
) == 0);
3891 gc_alloc_generation
= 0;
3893 update_x86_dynamic_space_free_pointer();
3894 auto_gc_trigger
= bytes_allocated
+ bytes_consed_between_gcs
;
3896 fprintf(stderr
,"Next gc when %ld bytes have been consed\n",
3898 SHOW("returning from collect_garbage");
3901 /* This is called by Lisp PURIFY when it is finished. All live objects
3902 * will have been moved to the RO and Static heaps. The dynamic space
3903 * will need a full re-initialization. We don't bother having Lisp
3904 * PURIFY flush the current gc_alloc() region, as the page_tables are
3905 * re-initialized, and every page is zeroed to be sure. */
3911 if (gencgc_verbose
> 1)
3912 SHOW("entering gc_free_heap");
3914 for (page
= 0; page
< NUM_PAGES
; page
++) {
3915 /* Skip free pages which should already be zero filled. */
3916 if (page_table
[page
].allocated
!= FREE_PAGE_FLAG
) {
3917 void *page_start
, *addr
;
3919 /* Mark the page free. The other slots are assumed invalid
3920 * when it is a FREE_PAGE_FLAG and bytes_used is 0 and it
3921 * should not be write-protected -- except that the
3922 * generation is used for the current region but it sets
3924 page_table
[page
].allocated
= FREE_PAGE_FLAG
;
3925 page_table
[page
].bytes_used
= 0;
3927 /* Zero the page. */
3928 page_start
= (void *)page_address(page
);
3930 /* First, remove any write-protection. */
3931 os_protect(page_start
, PAGE_BYTES
, OS_VM_PROT_ALL
);
3932 page_table
[page
].write_protected
= 0;
3934 os_invalidate(page_start
,PAGE_BYTES
);
3935 addr
= os_validate(page_start
,PAGE_BYTES
);
3936 if (addr
== NULL
|| addr
!= page_start
) {
3937 lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x",
3941 } else if (gencgc_zero_check_during_free_heap
) {
3942 /* Double-check that the page is zero filled. */
3943 long *page_start
, i
;
3944 gc_assert(page_table
[page
].allocated
== FREE_PAGE_FLAG
);
3945 gc_assert(page_table
[page
].bytes_used
== 0);
3946 page_start
= (long *)page_address(page
);
3947 for (i
=0; i
<1024; i
++) {
3948 if (page_start
[i
] != 0) {
3949 lose("free region not zero at %x", page_start
+ i
);
3955 bytes_allocated
= 0;
3957 /* Initialize the generations. */
3958 for (page
= 0; page
< NUM_GENERATIONS
; page
++) {
3959 generations
[page
].alloc_start_page
= 0;
3960 generations
[page
].alloc_unboxed_start_page
= 0;
3961 generations
[page
].alloc_large_start_page
= 0;
3962 generations
[page
].alloc_large_unboxed_start_page
= 0;
3963 generations
[page
].bytes_allocated
= 0;
3964 generations
[page
].gc_trigger
= 2000000;
3965 generations
[page
].num_gc
= 0;
3966 generations
[page
].cum_sum_bytes_allocated
= 0;
3969 if (gencgc_verbose
> 1)
3970 print_generation_stats(0);
3972 /* Initialize gc_alloc(). */
3973 gc_alloc_generation
= 0;
3975 gc_set_region_empty(&boxed_region
);
3976 gc_set_region_empty(&unboxed_region
);
3979 SetSymbolValue(ALLOCATION_POINTER
, (lispobj
)((char *)heap_base
),0);
3981 if (verify_after_free_heap
) {
3982 /* Check whether purify has left any bad pointers. */
3984 SHOW("checking after free_heap\n");
3995 scavtab
[SIMPLE_VECTOR_WIDETAG
] = scav_vector
;
3996 scavtab
[WEAK_POINTER_WIDETAG
] = scav_weak_pointer
;
3997 transother
[SIMPLE_ARRAY_WIDETAG
] = trans_boxed_large
;
3999 heap_base
= (void*)DYNAMIC_SPACE_START
;
4001 /* Initialize each page structure. */
4002 for (i
= 0; i
< NUM_PAGES
; i
++) {
4003 /* Initialize all pages as free. */
4004 page_table
[i
].allocated
= FREE_PAGE_FLAG
;
4005 page_table
[i
].bytes_used
= 0;
4007 /* Pages are not write-protected at startup. */
4008 page_table
[i
].write_protected
= 0;
4011 bytes_allocated
= 0;
4013 /* Initialize the generations.
4015 * FIXME: very similar to code in gc_free_heap(), should be shared */
4016 for (i
= 0; i
< NUM_GENERATIONS
; i
++) {
4017 generations
[i
].alloc_start_page
= 0;
4018 generations
[i
].alloc_unboxed_start_page
= 0;
4019 generations
[i
].alloc_large_start_page
= 0;
4020 generations
[i
].alloc_large_unboxed_start_page
= 0;
4021 generations
[i
].bytes_allocated
= 0;
4022 generations
[i
].gc_trigger
= 2000000;
4023 generations
[i
].num_gc
= 0;
4024 generations
[i
].cum_sum_bytes_allocated
= 0;
4025 /* the tune-able parameters */
4026 generations
[i
].bytes_consed_between_gc
= 2000000;
4027 generations
[i
].trigger_age
= 1;
4028 generations
[i
].min_av_mem_age
= 0.75;
4031 /* Initialize gc_alloc. */
4032 gc_alloc_generation
= 0;
4033 gc_set_region_empty(&boxed_region
);
4034 gc_set_region_empty(&unboxed_region
);
4040 /* Pick up the dynamic space from after a core load.
4042 * The ALLOCATION_POINTER points to the end of the dynamic space.
4046 gencgc_pickup_dynamic(void)
4049 long alloc_ptr
= SymbolValue(ALLOCATION_POINTER
,0);
4050 lispobj
*prev
=(lispobj
*)page_address(page
);
4053 lispobj
*first
,*ptr
= (lispobj
*)page_address(page
);
4054 page_table
[page
].allocated
= BOXED_PAGE_FLAG
;
4055 page_table
[page
].gen
= 0;
4056 page_table
[page
].bytes_used
= PAGE_BYTES
;
4057 page_table
[page
].large_object
= 0;
4059 first
=gc_search_space(prev
,(ptr
+2)-prev
,ptr
);
4060 if(ptr
== first
) prev
=ptr
;
4061 page_table
[page
].first_object_offset
=
4062 (void *)prev
- page_address(page
);
4064 } while (page_address(page
) < alloc_ptr
);
4066 generations
[0].bytes_allocated
= PAGE_BYTES
*page
;
4067 bytes_allocated
= PAGE_BYTES
*page
;
4073 gc_initialize_pointers(void)
4075 gencgc_pickup_dynamic();
4081 /* alloc(..) is the external interface for memory allocation. It
4082 * allocates to generation 0. It is not called from within the garbage
4083 * collector as it is only external uses that need the check for heap
4084 * size (GC trigger) and to disable the interrupts (interrupts are
4085 * always disabled during a GC).
4087 * The vops that call alloc(..) assume that the returned space is zero-filled.
4088 * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
4090 * The check for a GC trigger is only performed when the current
4091 * region is full, so in most cases it's not needed. */
4096 struct thread
*th
=arch_os_get_current_thread();
4097 struct alloc_region
*region
=
4098 #ifdef LISP_FEATURE_SB_THREAD
4099 th
? &(th
->alloc_region
) : &boxed_region
;
4104 void *new_free_pointer
;
4105 gc_assert(nbytes
>0);
4106 /* Check for alignment allocation problems. */
4107 gc_assert((((unsigned)region
->free_pointer
& LOWTAG_MASK
) == 0)
4108 && ((nbytes
& LOWTAG_MASK
) == 0));
4111 /* there are a few places in the C code that allocate data in the
4112 * heap before Lisp starts. This is before interrupts are enabled,
4113 * so we don't need to check for pseudo-atomic */
4114 #ifdef LISP_FEATURE_SB_THREAD
4115 if(!SymbolValue(PSEUDO_ATOMIC_ATOMIC
,th
)) {
4117 fprintf(stderr
, "fatal error in thread 0x%x, pid=%d\n",
4119 __asm__("movl %fs,%0" : "=r" (fs
) : );
4120 fprintf(stderr
, "fs is %x, th->tls_cookie=%x \n",
4121 debug_get_fs(),th
->tls_cookie
);
4122 lose("If you see this message before 2004.01.31, mail details to sbcl-devel\n");
4125 gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC
,th
));
4129 /* maybe we can do this quickly ... */
4130 new_free_pointer
= region
->free_pointer
+ nbytes
;
4131 if (new_free_pointer
<= region
->end_addr
) {
4132 new_obj
= (void*)(region
->free_pointer
);
4133 region
->free_pointer
= new_free_pointer
;
4134 return(new_obj
); /* yup */
4137 /* we have to go the long way around, it seems. Check whether
4138 * we should GC in the near future
4140 if (auto_gc_trigger
&& bytes_allocated
> auto_gc_trigger
) {
4141 struct thread
*thread
=arch_os_get_current_thread();
4142 /* Don't flood the system with interrupts if the need to gc is
4143 * already noted. This can happen for example when SUB-GC
4144 * allocates or after a gc triggered in a WITHOUT-GCING. */
4145 if (SymbolValue(NEED_TO_COLLECT_GARBAGE
,thread
) == NIL
) {
4146 /* set things up so that GC happens when we finish the PA
4147 * section. We only do this if there wasn't a pending
4148 * handler already, in case it was a gc. If it wasn't a
4149 * GC, the next allocation will get us back to this point
4150 * anyway, so no harm done
4152 struct interrupt_data
*data
=th
->interrupt_data
;
4153 sigset_t new_mask
,old_mask
;
4154 sigemptyset(&new_mask
);
4155 sigaddset_blockable(&new_mask
);
4156 sigprocmask(SIG_BLOCK
,&new_mask
,&old_mask
);
4158 if((!data
->pending_handler
) &&
4159 maybe_defer_handler(interrupt_maybe_gc_int
,data
,0,0,0)) {
4160 /* Leave the signals blocked just as if it was
4161 * deferred the normal way and set the
4163 sigcopyset(&(data
->pending_mask
),&old_mask
);
4164 SetSymbolValue(NEED_TO_COLLECT_GARBAGE
,T
,thread
);
4166 sigprocmask(SIG_SETMASK
,&old_mask
,0);
4170 new_obj
= gc_alloc_with_region(nbytes
,0,region
,0);
4175 * shared support for the OS-dependent signal handlers which
4176 * catch GENCGC-related write-protect violations
4179 void unhandled_sigmemoryfault(void);
4181 /* Depending on which OS we're running under, different signals might
4182 * be raised for a violation of write protection in the heap. This
4183 * function factors out the common generational GC magic which needs
4184 * to invoked in this case, and should be called from whatever signal
4185 * handler is appropriate for the OS we're running under.
4187 * Return true if this signal is a normal generational GC thing that
4188 * we were able to handle, or false if it was abnormal and control
4189 * should fall through to the general SIGSEGV/SIGBUS/whatever logic. */
4192 gencgc_handle_wp_violation(void* fault_addr
)
4194 long page_index
= find_page_index(fault_addr
);
4196 #ifdef QSHOW_SIGNALS
4197 FSHOW((stderr
, "heap WP violation? fault_addr=%x, page_index=%d\n",
4198 fault_addr
, page_index
));
4201 /* Check whether the fault is within the dynamic space. */
4202 if (page_index
== (-1)) {
4204 /* It can be helpful to be able to put a breakpoint on this
4205 * case to help diagnose low-level problems. */
4206 unhandled_sigmemoryfault();
4208 /* not within the dynamic space -- not our responsibility */
4212 if (page_table
[page_index
].write_protected
) {
4213 /* Unprotect the page. */
4214 os_protect(page_address(page_index
), PAGE_BYTES
, OS_VM_PROT_ALL
);
4215 page_table
[page_index
].write_protected_cleared
= 1;
4216 page_table
[page_index
].write_protected
= 0;
4218 /* The only acceptable reason for this signal on a heap
4219 * access is that GENCGC write-protected the page.
4220 * However, if two CPUs hit a wp page near-simultaneously,
4221 * we had better not have the second one lose here if it
4222 * does this test after the first one has already set wp=0
4224 if(page_table
[page_index
].write_protected_cleared
!= 1)
4225 lose("fault in heap page not marked as write-protected");
4227 /* Don't worry, we can handle it. */
4231 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
4232 * it's not just a case of the program hitting the write barrier, and
4233 * are about to let Lisp deal with it. It's basically just a
4234 * convenient place to set a gdb breakpoint. */
4236 unhandled_sigmemoryfault()
4239 void gc_alloc_update_all_page_tables(void)
4241 /* Flush the alloc regions updating the tables. */
4244 gc_alloc_update_page_tables(0, &th
->alloc_region
);
4245 gc_alloc_update_page_tables(1, &unboxed_region
);
4246 gc_alloc_update_page_tables(0, &boxed_region
);
4249 gc_set_region_empty(struct alloc_region
*region
)
4251 region
->first_page
= 0;
4252 region
->last_page
= -1;
4253 region
->start_addr
= page_address(0);
4254 region
->free_pointer
= page_address(0);
4255 region
->end_addr
= page_address(0);