1 /* -----------------------------------------------------------------------------
2 * $Id: Storage.c,v 1.65 2002/04/30 09:26:14 simonmar Exp $
4 * (c) The GHC Team, 1998-1999
6 * Storage manager front end
8 * ---------------------------------------------------------------------------*/
10 #include "PosixSource.h"
16 #include "BlockAlloc.h"
24 #include "OSThreads.h"
25 #include "StoragePriv.h"
27 #include "RetainerProfile.h" // for counting memory blocks (memInventory)
29 #ifdef darwin_TARGET_OS
30 #include <mach-o/getsect.h>
31 unsigned long macho_etext = 0;
32 unsigned long macho_edata = 0;
34 static void macosx_get_memory_layout(void)
36 struct segment_command *seg;
38 seg = getsegbyname("__TEXT");
39 macho_etext = seg->vmaddr + seg->vmsize;
40 seg = getsegbyname("__DATA");
41 macho_edata = seg->vmaddr + seg->vmsize;
45 StgClosure *caf_list = NULL;
47 bdescr *small_alloc_list; /* allocate()d small objects */
48 bdescr *large_alloc_list; /* allocate()d large objects */
49 bdescr *pinned_object_block; /* allocate pinned objects into this block */
50 nat alloc_blocks; /* number of allocate()d blocks since GC */
51 nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
53 StgPtr alloc_Hp = NULL; /* next free byte in small_alloc_list */
54 StgPtr alloc_HpLim = NULL; /* end of block at small_alloc_list */
56 generation *generations; /* all the generations */
57 generation *g0; /* generation 0, for convenience */
58 generation *oldest_gen; /* oldest generation, for convenience */
59 step *g0s0; /* generation 0, step 0, for convenience */
61 lnat total_allocated = 0; /* total memory allocated during run */
64 * Storage manager mutex: protects all the above state from
65 * simultaneous access by two STG threads.
68 Mutex sm_mutex = INIT_MUTEX_VAR;
74 static void *stgAllocForGMP (size_t size_in_bytes);
75 static void *stgReallocForGMP (void *ptr, size_t old_size, size_t new_size);
76 static void stgDeallocForGMP (void *ptr, size_t size);
85 #if defined(darwin_TARGET_OS)
86 macosx_get_memory_layout();
89 /* Sanity check to make sure we are able to make the distinction
90 * between closures and infotables
92 if (!LOOKS_LIKE_GHC_INFO(&stg_BLACKHOLE_info)) {
93 barf("LOOKS_LIKE_GHC_INFO+ is incorrectly defined");
96 if (LOOKS_LIKE_GHC_INFO(&stg_dummy_ret_closure)) {
97 barf("LOOKS_LIKE_GHC_INFO- is incorrectly defined");
100 if (LOOKS_LIKE_STATIC_CLOSURE(&stg_BLACKHOLE_info)) {
101 barf("LOOKS_LIKE_STATIC_CLOSURE- is incorrectly defined");
104 if (!LOOKS_LIKE_STATIC_CLOSURE(&stg_dummy_ret_closure)) {
105 barf("LOOKS_LIKE_STATIC_CLOSURE+ is incorrectly defined");
109 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
110 RtsFlags.GcFlags.heapSizeSuggestion >
111 RtsFlags.GcFlags.maxHeapSize) {
112 RtsFlags.GcFlags.maxHeapSize = RtsFlags.GcFlags.heapSizeSuggestion;
115 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
116 RtsFlags.GcFlags.minAllocAreaSize >
117 RtsFlags.GcFlags.maxHeapSize) {
118 prog_belch("maximum heap size (-M) is smaller than minimum alloc area size (-A)");
122 initBlockAllocator();
125 initCondition(&sm_mutex);
128 /* allocate generation info array */
129 generations = (generation *)stgMallocBytes(RtsFlags.GcFlags.generations
130 * sizeof(struct _generation),
131 "initStorage: gens");
133 /* Initialise all generations */
134 for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
135 gen = &generations[g];
137 gen->mut_list = END_MUT_LIST;
138 gen->mut_once_list = END_MUT_LIST;
139 gen->collections = 0;
140 gen->failed_promotions = 0;
144 /* A couple of convenience pointers */
145 g0 = &generations[0];
146 oldest_gen = &generations[RtsFlags.GcFlags.generations-1];
148 /* Allocate step structures in each generation */
149 if (RtsFlags.GcFlags.generations > 1) {
150 /* Only for multiple-generations */
152 /* Oldest generation: one step */
153 oldest_gen->n_steps = 1;
155 stgMallocBytes(1 * sizeof(struct _step), "initStorage: last step");
157 /* set up all except the oldest generation with 2 steps */
158 for(g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
159 generations[g].n_steps = RtsFlags.GcFlags.steps;
160 generations[g].steps =
161 stgMallocBytes (RtsFlags.GcFlags.steps * sizeof(struct _step),
162 "initStorage: steps");
166 /* single generation, i.e. a two-space collector */
168 g0->steps = stgMallocBytes (sizeof(struct _step), "initStorage: steps");
171 /* Initialise all steps */
172 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
173 for (s = 0; s < generations[g].n_steps; s++) {
174 stp = &generations[g].steps[s];
178 stp->gen = &generations[g];
185 stp->large_objects = NULL;
186 stp->n_large_blocks = 0;
187 stp->new_large_objects = NULL;
188 stp->scavenged_large_objects = NULL;
189 stp->n_scavenged_large_blocks = 0;
190 stp->is_compacted = 0;
195 /* Set up the destination pointers in each younger gen. step */
196 for (g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
197 for (s = 0; s < generations[g].n_steps-1; s++) {
198 generations[g].steps[s].to = &generations[g].steps[s+1];
200 generations[g].steps[s].to = &generations[g+1].steps[0];
203 /* The oldest generation has one step and it is compacted. */
204 if (RtsFlags.GcFlags.compact) {
205 if (RtsFlags.GcFlags.generations == 1) {
206 belch("WARNING: compaction is incompatible with -G1; disabled");
208 oldest_gen->steps[0].is_compacted = 1;
211 oldest_gen->steps[0].to = &oldest_gen->steps[0];
213 /* generation 0 is special: that's the nursery */
214 generations[0].max_blocks = 0;
216 /* G0S0: the allocation area. Policy: keep the allocation area
217 * small to begin with, even if we have a large suggested heap
218 * size. Reason: we're going to do a major collection first, and we
219 * don't want it to be a big one. This vague idea is borne out by
220 * rigorous experimental evidence.
222 g0s0 = &generations[0].steps[0];
226 weak_ptr_list = NULL;
229 /* initialise the allocate() interface */
230 small_alloc_list = NULL;
231 large_alloc_list = NULL;
233 alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
235 /* Tell GNU multi-precision pkg about our custom alloc functions */
236 mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
239 initMutex(&sm_mutex);
242 IF_DEBUG(gc, statDescribeGens());
248 stat_exit(calcAllocated());
251 /* -----------------------------------------------------------------------------
254 The entry code for every CAF does the following:
256 - builds a CAF_BLACKHOLE in the heap
257 - pushes an update frame pointing to the CAF_BLACKHOLE
258 - invokes UPD_CAF(), which:
259 - calls newCaf, below
260 - updates the CAF with a static indirection to the CAF_BLACKHOLE
262 Why do we build a BLACKHOLE in the heap rather than just updating
263 the thunk directly? It's so that we only need one kind of update
264 frame - otherwise we'd need a static version of the update frame too.
266 newCaf() does the following:
268 - it puts the CAF on the oldest generation's mut-once list.
269 This is so that we can treat the CAF as a root when collecting
272 For GHCI, we have additional requirements when dealing with CAFs:
274 - we must *retain* all dynamically-loaded CAFs ever entered,
275 just in case we need them again.
276 - we must be able to *revert* CAFs that have been evaluated, to
277 their pre-evaluated form.
279 To do this, we use an additional CAF list. When newCaf() is
280 called on a dynamically-loaded CAF, we add it to the CAF list
281 instead of the old-generation mutable list, and save away its
282 old info pointer (in caf->saved_info) for later reversion.
284 To revert all the CAFs, we traverse the CAF list and reset the
285 info pointer to caf->saved_info, then throw away the CAF list.
286 (see GC.c:revertCAFs()).
290 -------------------------------------------------------------------------- */
293 newCAF(StgClosure* caf)
295 /* Put this CAF on the mutable list for the old generation.
296 * This is a HACK - the IND_STATIC closure doesn't really have
297 * a mut_link field, but we pretend it has - in fact we re-use
298 * the STATIC_LINK field for the time being, because when we
299 * come to do a major GC we won't need the mut_link field
300 * any more and can use it as a STATIC_LINK.
304 if (is_dynamically_loaded_rwdata_ptr((StgPtr)caf)) {
305 ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
306 ((StgIndStatic *)caf)->static_link = caf_list;
309 ((StgIndStatic *)caf)->saved_info = NULL;
310 ((StgMutClosure *)caf)->mut_link = oldest_gen->mut_once_list;
311 oldest_gen->mut_once_list = (StgMutClosure *)caf;
317 /* If we are PAR or DIST then we never forget a CAF */
319 //belch("<##> Globalising CAF %08x %s",caf,info_type(caf));
320 newGA=makeGlobal(caf,rtsTrue); /*given full weight*/
326 /* -----------------------------------------------------------------------------
328 -------------------------------------------------------------------------- */
331 allocNurseries( void )
340 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
341 cap->r.rNursery = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
342 cap->r.rCurrentNursery = cap->r.rNursery;
343 for (bd = cap->r.rNursery; bd != NULL; bd = bd->link) {
344 bd->u.back = (bdescr *)cap;
347 /* Set the back links to be equal to the Capability,
348 * so we can do slightly better informed locking.
352 g0s0->blocks = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
353 g0s0->n_blocks = RtsFlags.GcFlags.minAllocAreaSize;
354 g0s0->to_blocks = NULL;
355 g0s0->n_to_blocks = 0;
356 MainCapability.r.rNursery = g0s0->blocks;
357 MainCapability.r.rCurrentNursery = g0s0->blocks;
358 /* hp, hpLim, hp_bd, to_space etc. aren't used in G0S0 */
363 resetNurseries( void )
369 /* All tasks must be stopped */
370 ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes);
372 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
373 for (bd = cap->r.rNursery; bd; bd = bd->link) {
374 bd->free = bd->start;
375 ASSERT(bd->gen_no == 0);
376 ASSERT(bd->step == g0s0);
377 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
379 cap->r.rCurrentNursery = cap->r.rNursery;
382 for (bd = g0s0->blocks; bd; bd = bd->link) {
383 bd->free = bd->start;
384 ASSERT(bd->gen_no == 0);
385 ASSERT(bd->step == g0s0);
386 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
388 MainCapability.r.rNursery = g0s0->blocks;
389 MainCapability.r.rCurrentNursery = g0s0->blocks;
394 allocNursery (bdescr *tail, nat blocks)
399 // Allocate a nursery: we allocate fresh blocks one at a time and
400 // cons them on to the front of the list, not forgetting to update
401 // the back pointer on the tail of the list to point to the new block.
402 for (i=0; i < blocks; i++) {
405 processNursery() in LdvProfile.c assumes that every block group in
406 the nursery contains only a single block. So, if a block group is
407 given multiple blocks, change processNursery() accordingly.
411 // double-link the nursery: we might need to insert blocks
418 bd->free = bd->start;
426 resizeNursery ( nat blocks )
432 barf("resizeNursery: can't resize in SMP mode");
435 nursery_blocks = g0s0->n_blocks;
436 if (nursery_blocks == blocks) {
440 else if (nursery_blocks < blocks) {
441 IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n",
443 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
449 IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n",
453 while (nursery_blocks > blocks) {
455 next_bd->u.back = NULL;
456 nursery_blocks -= bd->blocks; // might be a large block
461 // might have gone just under, by freeing a large block, so make
462 // up the difference.
463 if (nursery_blocks < blocks) {
464 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
468 g0s0->n_blocks = blocks;
469 ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
472 /* -----------------------------------------------------------------------------
473 The allocate() interface
475 allocate(n) always succeeds, and returns a chunk of memory n words
476 long. n can be larger than the size of a block if necessary, in
477 which case a contiguous block group will be allocated.
478 -------------------------------------------------------------------------- */
488 TICK_ALLOC_HEAP_NOCTR(n);
491 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
492 /* ToDo: allocate directly into generation 1 */
493 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
494 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
495 bd = allocGroup(req_blocks);
496 dbl_link_onto(bd, &g0s0->large_objects);
499 bd->flags = BF_LARGE;
500 bd->free = bd->start;
501 /* don't add these blocks to alloc_blocks, since we're assuming
502 * that large objects are likely to remain live for quite a while
503 * (eg. running threads), so garbage collecting early won't make
506 alloc_blocks += req_blocks;
510 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
511 } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
512 if (small_alloc_list) {
513 small_alloc_list->free = alloc_Hp;
516 bd->link = small_alloc_list;
517 small_alloc_list = bd;
521 alloc_Hp = bd->start;
522 alloc_HpLim = bd->start + BLOCK_SIZE_W;
533 allocated_bytes( void )
535 return (alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp));
538 /* ---------------------------------------------------------------------------
539 Allocate a fixed/pinned object.
541 We allocate small pinned objects into a single block, allocating a
542 new block when the current one overflows. The block is chained
543 onto the large_object_list of generation 0 step 0.
545 NOTE: The GC can't in general handle pinned objects. This
546 interface is only safe to use for ByteArrays, which have no
547 pointers and don't require scavenging. It works because the
548 block's descriptor has the BF_LARGE flag set, so the block is
549 treated as a large object and chained onto various lists, rather
550 than the individual objects being copied. However, when it comes
551 to scavenge the block, the GC will only scavenge the first object.
552 The reason is that the GC can't linearly scan a block of pinned
553 objects at the moment (doing so would require using the
554 mostly-copying techniques). But since we're restricting ourselves
555 to pinned ByteArrays, not scavenging is ok.
557 This function is called by newPinnedByteArray# which immediately
558 fills the allocated memory with a MutableByteArray#.
559 ------------------------------------------------------------------------- */
562 allocatePinned( nat n )
565 bdescr *bd = pinned_object_block;
569 TICK_ALLOC_HEAP_NOCTR(n);
572 // If the request is for a large object, then allocate()
573 // will give us a pinned object anyway.
574 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
579 // we always return 8-byte aligned memory. bd->free must be
580 // 8-byte aligned to begin with, so we just round up n to
581 // the nearest multiple of 8 bytes.
582 if (sizeof(StgWord) == 4) {
586 // If we don't have a block of pinned objects yet, or the current
587 // one isn't large enough to hold the new object, allocate a new one.
588 if (bd == NULL || (bd->free + n) > (bd->start + BLOCK_SIZE_W)) {
589 pinned_object_block = bd = allocBlock();
590 dbl_link_onto(bd, &g0s0->large_objects);
593 bd->flags = BF_LARGE;
594 bd->free = bd->start;
604 /* -----------------------------------------------------------------------------
605 Allocation functions for GMP.
607 These all use the allocate() interface - we can't have any garbage
608 collection going on during a gmp operation, so we use allocate()
609 which always succeeds. The gmp operations which might need to
610 allocate will ask the storage manager (via doYouWantToGC()) whether
611 a garbage collection is required, in case we get into a loop doing
612 only allocate() style allocation.
613 -------------------------------------------------------------------------- */
616 stgAllocForGMP (size_t size_in_bytes)
619 nat data_size_in_words, total_size_in_words;
621 /* should be a multiple of sizeof(StgWord) (whole no. of limbs) */
622 ASSERT(size_in_bytes % sizeof(W_) == 0);
624 data_size_in_words = size_in_bytes / sizeof(W_);
625 total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
627 /* allocate and fill it in. */
628 arr = (StgArrWords *)allocate(total_size_in_words);
629 SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
631 /* and return a ptr to the goods inside the array */
632 return(BYTE_ARR_CTS(arr));
636 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
638 void *new_stuff_ptr = stgAllocForGMP(new_size);
640 char *p = (char *) ptr;
641 char *q = (char *) new_stuff_ptr;
643 for (; i < old_size; i++, p++, q++) {
647 return(new_stuff_ptr);
651 stgDeallocForGMP (void *ptr STG_UNUSED,
652 size_t size STG_UNUSED)
654 /* easy for us: the garbage collector does the dealloc'n */
657 /* -----------------------------------------------------------------------------
659 * -------------------------------------------------------------------------- */
661 /* -----------------------------------------------------------------------------
664 * Approximate how much we've allocated: number of blocks in the
665 * nursery + blocks allocated via allocate() - unused nusery blocks.
666 * This leaves a little slop at the end of each block, and doesn't
667 * take into account large objects (ToDo).
668 * -------------------------------------------------------------------------- */
671 calcAllocated( void )
679 /* All tasks must be stopped. Can't assert that all the
680 capabilities are owned by the scheduler, though: one or more
681 tasks might have been stopped while they were running (non-main)
683 /* ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes); */
686 n_free_capabilities * RtsFlags.GcFlags.minAllocAreaSize * BLOCK_SIZE_W
689 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
690 for ( bd = cap->r.rCurrentNursery->link; bd != NULL; bd = bd->link ) {
691 allocated -= BLOCK_SIZE_W;
693 if (cap->r.rCurrentNursery->free < cap->r.rCurrentNursery->start
695 allocated -= (cap->r.rCurrentNursery->start + BLOCK_SIZE_W)
696 - cap->r.rCurrentNursery->free;
701 bdescr *current_nursery = MainCapability.r.rCurrentNursery;
703 allocated = (g0s0->n_blocks * BLOCK_SIZE_W) + allocated_bytes();
704 for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
705 allocated -= BLOCK_SIZE_W;
707 if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
708 allocated -= (current_nursery->start + BLOCK_SIZE_W)
709 - current_nursery->free;
713 total_allocated += allocated;
717 /* Approximate the amount of live data in the heap. To be called just
718 * after garbage collection (see GarbageCollect()).
727 if (RtsFlags.GcFlags.generations == 1) {
728 live = (g0s0->n_to_blocks - 1) * BLOCK_SIZE_W +
729 ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
733 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
734 for (s = 0; s < generations[g].n_steps; s++) {
735 /* approximate amount of live data (doesn't take into account slop
736 * at end of each block).
738 if (g == 0 && s == 0) {
741 stp = &generations[g].steps[s];
742 live += (stp->n_large_blocks + stp->n_blocks - 1) * BLOCK_SIZE_W;
743 if (stp->hp_bd != NULL) {
744 live += ((lnat)stp->hp_bd->free - (lnat)stp->hp_bd->start)
752 /* Approximate the number of blocks that will be needed at the next
753 * garbage collection.
755 * Assume: all data currently live will remain live. Steps that will
756 * be collected next time will therefore need twice as many blocks
757 * since all the data will be copied.
766 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
767 for (s = 0; s < generations[g].n_steps; s++) {
768 if (g == 0 && s == 0) { continue; }
769 stp = &generations[g].steps[s];
770 if (generations[g].steps[0].n_blocks +
771 generations[g].steps[0].n_large_blocks
772 > generations[g].max_blocks
773 && stp->is_compacted == 0) {
774 needed += 2 * stp->n_blocks;
776 needed += stp->n_blocks;
783 /* -----------------------------------------------------------------------------
786 memInventory() checks for memory leaks by counting up all the
787 blocks we know about and comparing that to the number of blocks
788 allegedly floating around in the system.
789 -------------------------------------------------------------------------- */
799 lnat total_blocks = 0, free_blocks = 0;
801 /* count the blocks we current have */
803 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
804 for (s = 0; s < generations[g].n_steps; s++) {
805 stp = &generations[g].steps[s];
806 total_blocks += stp->n_blocks;
807 if (RtsFlags.GcFlags.generations == 1) {
808 /* two-space collector has a to-space too :-) */
809 total_blocks += g0s0->n_to_blocks;
811 for (bd = stp->large_objects; bd; bd = bd->link) {
812 total_blocks += bd->blocks;
813 /* hack for megablock groups: they have an extra block or two in
814 the second and subsequent megablocks where the block
815 descriptors would normally go.
817 if (bd->blocks > BLOCKS_PER_MBLOCK) {
818 total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
819 * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
825 /* any blocks held by allocate() */
826 for (bd = small_alloc_list; bd; bd = bd->link) {
827 total_blocks += bd->blocks;
829 for (bd = large_alloc_list; bd; bd = bd->link) {
830 total_blocks += bd->blocks;
834 if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
835 for (bd = firstStack; bd != NULL; bd = bd->link)
836 total_blocks += bd->blocks;
840 // count the blocks allocated by the arena allocator
841 total_blocks += arenaBlocks();
843 /* count the blocks on the free list */
844 free_blocks = countFreeList();
846 if (total_blocks + free_blocks != mblocks_allocated *
848 fprintf(stderr, "Blocks: %ld live + %ld free = %ld total (%ld around)\n",
849 total_blocks, free_blocks, total_blocks + free_blocks,
850 mblocks_allocated * BLOCKS_PER_MBLOCK);
853 ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
858 countBlocks(bdescr *bd)
861 for (n=0; bd != NULL; bd=bd->link) {
867 /* Full heap sanity check. */
873 if (RtsFlags.GcFlags.generations == 1) {
874 checkHeap(g0s0->to_blocks);
875 checkChain(g0s0->large_objects);
878 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
879 for (s = 0; s < generations[g].n_steps; s++) {
880 ASSERT(countBlocks(generations[g].steps[s].blocks)
881 == generations[g].steps[s].n_blocks);
882 ASSERT(countBlocks(generations[g].steps[s].large_objects)
883 == generations[g].steps[s].n_large_blocks);
884 if (g == 0 && s == 0) { continue; }
885 checkHeap(generations[g].steps[s].blocks);
886 checkChain(generations[g].steps[s].large_objects);
888 checkMutableList(generations[g].mut_list, g);
889 checkMutOnceList(generations[g].mut_once_list, g);
893 checkFreeListSanity();
897 // handy function for use in gdb, because Bdescr() is inlined.
898 extern bdescr *_bdescr( StgPtr p );