1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
5 * Storage manager front end
7 * ---------------------------------------------------------------------------*/
9 #include "PosixSource.h"
15 #include "BlockAlloc.h"
20 #include "OSThreads.h"
21 #include "Capability.h"
24 #include "RetainerProfile.h" // for counting memory blocks (memInventory)
30 * All these globals require sm_mutex to access in THREADED_RTS mode.
32 StgClosure *caf_list = NULL;
33 StgClosure *revertible_caf_list = NULL;
36 bdescr *small_alloc_list; /* allocate()d small objects */
37 bdescr *pinned_object_block; /* allocate pinned objects into this block */
38 nat alloc_blocks; /* number of allocate()d blocks since GC */
39 nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
41 StgPtr alloc_Hp = NULL; /* next free byte in small_alloc_list */
42 StgPtr alloc_HpLim = NULL; /* end of block at small_alloc_list */
44 generation *generations = NULL; /* all the generations */
45 generation *g0 = NULL; /* generation 0, for convenience */
46 generation *oldest_gen = NULL; /* oldest generation, for convenience */
47 step *g0s0 = NULL; /* generation 0, step 0, for convenience */
49 ullong total_allocated = 0; /* total memory allocated during run */
51 nat n_nurseries = 0; /* == RtsFlags.ParFlags.nNodes, convenience */
52 step *nurseries = NULL; /* array of nurseries, >1 only if THREADED_RTS */
56 * Storage manager mutex: protects all the above state from
57 * simultaneous access by two STG threads.
61 * This mutex is used by atomicModifyMutVar# only
63 Mutex atomic_modify_mutvar_mutex;
70 static void *stgAllocForGMP (size_t size_in_bytes);
71 static void *stgReallocForGMP (void *ptr, size_t old_size, size_t new_size);
72 static void stgDeallocForGMP (void *ptr, size_t size);
75 initStep (step *stp, int g, int s)
80 stp->old_blocks = NULL;
81 stp->n_old_blocks = 0;
82 stp->gen = &generations[g];
88 stp->scavd_hpLim = NULL;
91 stp->large_objects = NULL;
92 stp->n_large_blocks = 0;
93 stp->new_large_objects = NULL;
94 stp->scavenged_large_objects = NULL;
95 stp->n_scavenged_large_blocks = 0;
96 stp->is_compacted = 0;
106 if (generations != NULL) {
107 // multi-init protection
111 /* Sanity check to make sure the LOOKS_LIKE_ macros appear to be
112 * doing something reasonable.
114 ASSERT(LOOKS_LIKE_INFO_PTR(&stg_BLACKHOLE_info));
115 ASSERT(LOOKS_LIKE_CLOSURE_PTR(&stg_dummy_ret_closure));
116 ASSERT(!HEAP_ALLOCED(&stg_dummy_ret_closure));
118 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
119 RtsFlags.GcFlags.heapSizeSuggestion >
120 RtsFlags.GcFlags.maxHeapSize) {
121 RtsFlags.GcFlags.maxHeapSize = RtsFlags.GcFlags.heapSizeSuggestion;
124 if (RtsFlags.GcFlags.maxHeapSize != 0 &&
125 RtsFlags.GcFlags.minAllocAreaSize >
126 RtsFlags.GcFlags.maxHeapSize) {
127 errorBelch("maximum heap size (-M) is smaller than minimum alloc area size (-A)");
131 initBlockAllocator();
133 #if defined(THREADED_RTS)
134 initMutex(&sm_mutex);
135 initMutex(&atomic_modify_mutvar_mutex);
140 /* allocate generation info array */
141 generations = (generation *)stgMallocBytes(RtsFlags.GcFlags.generations
142 * sizeof(struct generation_),
143 "initStorage: gens");
145 /* Initialise all generations */
146 for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
147 gen = &generations[g];
149 gen->mut_list = allocBlock();
150 gen->collections = 0;
151 gen->failed_promotions = 0;
155 /* A couple of convenience pointers */
156 g0 = &generations[0];
157 oldest_gen = &generations[RtsFlags.GcFlags.generations-1];
159 /* Allocate step structures in each generation */
160 if (RtsFlags.GcFlags.generations > 1) {
161 /* Only for multiple-generations */
163 /* Oldest generation: one step */
164 oldest_gen->n_steps = 1;
166 stgMallocBytes(1 * sizeof(struct step_), "initStorage: last step");
168 /* set up all except the oldest generation with 2 steps */
169 for(g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
170 generations[g].n_steps = RtsFlags.GcFlags.steps;
171 generations[g].steps =
172 stgMallocBytes (RtsFlags.GcFlags.steps * sizeof(struct step_),
173 "initStorage: steps");
177 /* single generation, i.e. a two-space collector */
179 g0->steps = stgMallocBytes (sizeof(struct step_), "initStorage: steps");
183 n_nurseries = n_capabilities;
184 nurseries = stgMallocBytes (n_nurseries * sizeof(struct step_),
185 "initStorage: nurseries");
188 nurseries = g0->steps; // just share nurseries[0] with g0s0
191 /* Initialise all steps */
192 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
193 for (s = 0; s < generations[g].n_steps; s++) {
194 initStep(&generations[g].steps[s], g, s);
199 for (s = 0; s < n_nurseries; s++) {
200 initStep(&nurseries[s], 0, s);
204 /* Set up the destination pointers in each younger gen. step */
205 for (g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
206 for (s = 0; s < generations[g].n_steps-1; s++) {
207 generations[g].steps[s].to = &generations[g].steps[s+1];
209 generations[g].steps[s].to = &generations[g+1].steps[0];
211 oldest_gen->steps[0].to = &oldest_gen->steps[0];
214 for (s = 0; s < n_nurseries; s++) {
215 nurseries[s].to = generations[0].steps[0].to;
219 /* The oldest generation has one step. */
220 if (RtsFlags.GcFlags.compact) {
221 if (RtsFlags.GcFlags.generations == 1) {
222 errorBelch("WARNING: compaction is incompatible with -G1; disabled");
224 oldest_gen->steps[0].is_compacted = 1;
229 if (RtsFlags.GcFlags.generations == 1) {
230 errorBelch("-G1 is incompatible with -threaded");
231 stg_exit(EXIT_FAILURE);
235 /* generation 0 is special: that's the nursery */
236 generations[0].max_blocks = 0;
238 /* G0S0: the allocation area. Policy: keep the allocation area
239 * small to begin with, even if we have a large suggested heap
240 * size. Reason: we're going to do a major collection first, and we
241 * don't want it to be a big one. This vague idea is borne out by
242 * rigorous experimental evidence.
244 g0s0 = &generations[0].steps[0];
248 weak_ptr_list = NULL;
250 revertible_caf_list = NULL;
252 /* initialise the allocate() interface */
253 small_alloc_list = NULL;
255 alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
257 /* Tell GNU multi-precision pkg about our custom alloc functions */
258 mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
260 IF_DEBUG(gc, statDescribeGens());
268 stat_exit(calcAllocated());
271 /* -----------------------------------------------------------------------------
274 The entry code for every CAF does the following:
276 - builds a CAF_BLACKHOLE in the heap
277 - pushes an update frame pointing to the CAF_BLACKHOLE
278 - invokes UPD_CAF(), which:
279 - calls newCaf, below
280 - updates the CAF with a static indirection to the CAF_BLACKHOLE
282 Why do we build a BLACKHOLE in the heap rather than just updating
283 the thunk directly? It's so that we only need one kind of update
284 frame - otherwise we'd need a static version of the update frame too.
286 newCaf() does the following:
288 - it puts the CAF on the oldest generation's mut-once list.
289 This is so that we can treat the CAF as a root when collecting
292 For GHCI, we have additional requirements when dealing with CAFs:
294 - we must *retain* all dynamically-loaded CAFs ever entered,
295 just in case we need them again.
296 - we must be able to *revert* CAFs that have been evaluated, to
297 their pre-evaluated form.
299 To do this, we use an additional CAF list. When newCaf() is
300 called on a dynamically-loaded CAF, we add it to the CAF list
301 instead of the old-generation mutable list, and save away its
302 old info pointer (in caf->saved_info) for later reversion.
304 To revert all the CAFs, we traverse the CAF list and reset the
305 info pointer to caf->saved_info, then throw away the CAF list.
306 (see GC.c:revertCAFs()).
310 -------------------------------------------------------------------------- */
313 newCAF(StgClosure* caf)
320 // If we are in GHCi _and_ we are using dynamic libraries,
321 // then we can't redirect newCAF calls to newDynCAF (see below),
322 // so we make newCAF behave almost like newDynCAF.
323 // The dynamic libraries might be used by both the interpreted
324 // program and GHCi itself, so they must not be reverted.
325 // This also means that in GHCi with dynamic libraries, CAFs are not
326 // garbage collected. If this turns out to be a problem, we could
327 // do another hack here and do an address range test on caf to figure
328 // out whether it is from a dynamic library.
329 ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
330 ((StgIndStatic *)caf)->static_link = caf_list;
335 /* Put this CAF on the mutable list for the old generation.
336 * This is a HACK - the IND_STATIC closure doesn't really have
337 * a mut_link field, but we pretend it has - in fact we re-use
338 * the STATIC_LINK field for the time being, because when we
339 * come to do a major GC we won't need the mut_link field
340 * any more and can use it as a STATIC_LINK.
342 ((StgIndStatic *)caf)->saved_info = NULL;
343 recordMutableGen(caf, oldest_gen);
349 /* If we are PAR or DIST then we never forget a CAF */
351 //debugBelch("<##> Globalising CAF %08x %s",caf,info_type(caf));
352 newGA=makeGlobal(caf,rtsTrue); /*given full weight*/
358 // An alternate version of newCaf which is used for dynamically loaded
359 // object code in GHCi. In this case we want to retain *all* CAFs in
360 // the object code, because they might be demanded at any time from an
361 // expression evaluated on the command line.
362 // Also, GHCi might want to revert CAFs, so we add these to the
363 // revertible_caf_list.
365 // The linker hackily arranges that references to newCaf from dynamic
366 // code end up pointing to newDynCAF.
368 newDynCAF(StgClosure *caf)
372 ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
373 ((StgIndStatic *)caf)->static_link = revertible_caf_list;
374 revertible_caf_list = caf;
379 /* -----------------------------------------------------------------------------
381 -------------------------------------------------------------------------- */
384 allocNursery (step *stp, bdescr *tail, nat blocks)
389 // Allocate a nursery: we allocate fresh blocks one at a time and
390 // cons them on to the front of the list, not forgetting to update
391 // the back pointer on the tail of the list to point to the new block.
392 for (i=0; i < blocks; i++) {
395 processNursery() in LdvProfile.c assumes that every block group in
396 the nursery contains only a single block. So, if a block group is
397 given multiple blocks, change processNursery() accordingly.
401 // double-link the nursery: we might need to insert blocks
408 bd->free = bd->start;
416 assignNurseriesToCapabilities (void)
421 for (i = 0; i < n_nurseries; i++) {
422 capabilities[i].r.rNursery = &nurseries[i];
423 capabilities[i].r.rCurrentNursery = nurseries[i].blocks;
424 capabilities[i].r.rCurrentAlloc = NULL;
426 #else /* THREADED_RTS */
427 MainCapability.r.rNursery = &nurseries[0];
428 MainCapability.r.rCurrentNursery = nurseries[0].blocks;
429 MainCapability.r.rCurrentAlloc = NULL;
434 allocNurseries( void )
438 for (i = 0; i < n_nurseries; i++) {
439 nurseries[i].blocks =
440 allocNursery(&nurseries[i], NULL,
441 RtsFlags.GcFlags.minAllocAreaSize);
442 nurseries[i].n_blocks = RtsFlags.GcFlags.minAllocAreaSize;
443 nurseries[i].old_blocks = NULL;
444 nurseries[i].n_old_blocks = 0;
445 /* hp, hpLim, hp_bd, to_space etc. aren't used in the nursery */
447 assignNurseriesToCapabilities();
451 resetNurseries( void )
457 for (i = 0; i < n_nurseries; i++) {
459 for (bd = stp->blocks; bd; bd = bd->link) {
460 bd->free = bd->start;
461 ASSERT(bd->gen_no == 0);
462 ASSERT(bd->step == stp);
463 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
466 assignNurseriesToCapabilities();
470 countNurseryBlocks (void)
475 for (i = 0; i < n_nurseries; i++) {
476 blocks += nurseries[i].n_blocks;
482 resizeNursery ( step *stp, nat blocks )
487 nursery_blocks = stp->n_blocks;
488 if (nursery_blocks == blocks) return;
490 if (nursery_blocks < blocks) {
491 IF_DEBUG(gc, debugBelch("Increasing size of nursery to %d blocks\n",
493 stp->blocks = allocNursery(stp, stp->blocks, blocks-nursery_blocks);
498 IF_DEBUG(gc, debugBelch("Decreasing size of nursery to %d blocks\n",
502 while (nursery_blocks > blocks) {
504 next_bd->u.back = NULL;
505 nursery_blocks -= bd->blocks; // might be a large block
510 // might have gone just under, by freeing a large block, so make
511 // up the difference.
512 if (nursery_blocks < blocks) {
513 stp->blocks = allocNursery(stp, stp->blocks, blocks-nursery_blocks);
517 stp->n_blocks = blocks;
518 ASSERT(countBlocks(stp->blocks) == stp->n_blocks);
522 // Resize each of the nurseries to the specified size.
525 resizeNurseriesFixed (nat blocks)
528 for (i = 0; i < n_nurseries; i++) {
529 resizeNursery(&nurseries[i], blocks);
534 // Resize the nurseries to the total specified size.
537 resizeNurseries (nat blocks)
539 // If there are multiple nurseries, then we just divide the number
540 // of available blocks between them.
541 resizeNurseriesFixed(blocks / n_nurseries);
544 /* -----------------------------------------------------------------------------
545 The allocate() interface
547 allocate(n) always succeeds, and returns a chunk of memory n words
548 long. n can be larger than the size of a block if necessary, in
549 which case a contiguous block group will be allocated.
550 -------------------------------------------------------------------------- */
560 TICK_ALLOC_HEAP_NOCTR(n);
563 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
564 /* ToDo: allocate directly into generation 1 */
565 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
566 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
567 bd = allocGroup(req_blocks);
568 dbl_link_onto(bd, &g0s0->large_objects);
569 g0s0->n_large_blocks += req_blocks;
572 bd->flags = BF_LARGE;
573 bd->free = bd->start + n;
574 alloc_blocks += req_blocks;
578 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
579 } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
580 if (small_alloc_list) {
581 small_alloc_list->free = alloc_Hp;
584 bd->link = small_alloc_list;
585 small_alloc_list = bd;
589 alloc_Hp = bd->start;
590 alloc_HpLim = bd->start + BLOCK_SIZE_W;
601 allocated_bytes( void )
605 allocated = alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp);
606 if (pinned_object_block != NULL) {
607 allocated -= (pinned_object_block->start + BLOCK_SIZE_W) -
608 pinned_object_block->free;
615 tidyAllocateLists (void)
617 if (small_alloc_list != NULL) {
618 ASSERT(alloc_Hp >= small_alloc_list->start &&
619 alloc_Hp <= small_alloc_list->start + BLOCK_SIZE);
620 small_alloc_list->free = alloc_Hp;
624 /* -----------------------------------------------------------------------------
627 This allocates memory in the current thread - it is intended for
628 use primarily from STG-land where we have a Capability. It is
629 better than allocate() because it doesn't require taking the
630 sm_mutex lock in the common case.
632 Memory is allocated directly from the nursery if possible (but not
633 from the current nursery block, so as not to interfere with
635 -------------------------------------------------------------------------- */
638 allocateLocal (Capability *cap, nat n)
643 TICK_ALLOC_HEAP_NOCTR(n);
646 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
647 /* ToDo: allocate directly into generation 1 */
648 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
649 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
651 bd = allocGroup(req_blocks);
652 dbl_link_onto(bd, &g0s0->large_objects);
653 g0s0->n_large_blocks += req_blocks;
656 bd->flags = BF_LARGE;
657 bd->free = bd->start + n;
658 alloc_blocks += req_blocks;
662 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
665 bd = cap->r.rCurrentAlloc;
666 if (bd == NULL || bd->free + n > bd->start + BLOCK_SIZE_W) {
668 // The CurrentAlloc block is full, we need to find another
669 // one. First, we try taking the next block from the
671 bd = cap->r.rCurrentNursery->link;
673 if (bd == NULL || bd->free + n > bd->start + BLOCK_SIZE_W) {
674 // The nursery is empty, or the next block is already
675 // full: allocate a fresh block (we can't fail here).
678 cap->r.rNursery->n_blocks++;
681 bd->step = cap->r.rNursery;
684 // we have a block in the nursery: take it and put
685 // it at the *front* of the nursery list, and use it
686 // to allocate() from.
687 cap->r.rCurrentNursery->link = bd->link;
688 if (bd->link != NULL) {
689 bd->link->u.back = cap->r.rCurrentNursery;
692 dbl_link_onto(bd, &cap->r.rNursery->blocks);
693 cap->r.rCurrentAlloc = bd;
694 IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
702 /* ---------------------------------------------------------------------------
703 Allocate a fixed/pinned object.
705 We allocate small pinned objects into a single block, allocating a
706 new block when the current one overflows. The block is chained
707 onto the large_object_list of generation 0 step 0.
709 NOTE: The GC can't in general handle pinned objects. This
710 interface is only safe to use for ByteArrays, which have no
711 pointers and don't require scavenging. It works because the
712 block's descriptor has the BF_LARGE flag set, so the block is
713 treated as a large object and chained onto various lists, rather
714 than the individual objects being copied. However, when it comes
715 to scavenge the block, the GC will only scavenge the first object.
716 The reason is that the GC can't linearly scan a block of pinned
717 objects at the moment (doing so would require using the
718 mostly-copying techniques). But since we're restricting ourselves
719 to pinned ByteArrays, not scavenging is ok.
721 This function is called by newPinnedByteArray# which immediately
722 fills the allocated memory with a MutableByteArray#.
723 ------------------------------------------------------------------------- */
726 allocatePinned( nat n )
729 bdescr *bd = pinned_object_block;
731 // If the request is for a large object, then allocate()
732 // will give us a pinned object anyway.
733 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
739 TICK_ALLOC_HEAP_NOCTR(n);
742 // we always return 8-byte aligned memory. bd->free must be
743 // 8-byte aligned to begin with, so we just round up n to
744 // the nearest multiple of 8 bytes.
745 if (sizeof(StgWord) == 4) {
749 // If we don't have a block of pinned objects yet, or the current
750 // one isn't large enough to hold the new object, allocate a new one.
751 if (bd == NULL || (bd->free + n) > (bd->start + BLOCK_SIZE_W)) {
752 pinned_object_block = bd = allocBlock();
753 dbl_link_onto(bd, &g0s0->large_objects);
756 bd->flags = BF_PINNED | BF_LARGE;
757 bd->free = bd->start;
767 /* -----------------------------------------------------------------------------
768 This is the write barrier for MUT_VARs, a.k.a. IORefs. A
769 MUT_VAR_CLEAN object is not on the mutable list; a MUT_VAR_DIRTY
770 is. When written to, a MUT_VAR_CLEAN turns into a MUT_VAR_DIRTY
771 and is put on the mutable list.
772 -------------------------------------------------------------------------- */
775 dirty_MUT_VAR(StgRegTable *reg, StgClosure *p)
777 Capability *cap = regTableToCapability(reg);
779 if (p->header.info == &stg_MUT_VAR_CLEAN_info) {
780 p->header.info = &stg_MUT_VAR_DIRTY_info;
781 bd = Bdescr((StgPtr)p);
782 if (bd->gen_no > 0) recordMutableCap(p,cap,bd->gen_no);
786 /* -----------------------------------------------------------------------------
787 Allocation functions for GMP.
789 These all use the allocate() interface - we can't have any garbage
790 collection going on during a gmp operation, so we use allocate()
791 which always succeeds. The gmp operations which might need to
792 allocate will ask the storage manager (via doYouWantToGC()) whether
793 a garbage collection is required, in case we get into a loop doing
794 only allocate() style allocation.
795 -------------------------------------------------------------------------- */
798 stgAllocForGMP (size_t size_in_bytes)
801 nat data_size_in_words, total_size_in_words;
803 /* round up to a whole number of words */
804 data_size_in_words = (size_in_bytes + sizeof(W_) + 1) / sizeof(W_);
805 total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
807 /* allocate and fill it in. */
808 #if defined(THREADED_RTS)
809 arr = (StgArrWords *)allocateLocal(myTask()->cap, total_size_in_words);
811 arr = (StgArrWords *)allocateLocal(&MainCapability, total_size_in_words);
813 SET_ARR_HDR(arr, &stg_ARR_WORDS_info, CCCS, data_size_in_words);
815 /* and return a ptr to the goods inside the array */
820 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
822 void *new_stuff_ptr = stgAllocForGMP(new_size);
824 char *p = (char *) ptr;
825 char *q = (char *) new_stuff_ptr;
827 for (; i < old_size; i++, p++, q++) {
831 return(new_stuff_ptr);
835 stgDeallocForGMP (void *ptr STG_UNUSED,
836 size_t size STG_UNUSED)
838 /* easy for us: the garbage collector does the dealloc'n */
841 /* -----------------------------------------------------------------------------
843 * -------------------------------------------------------------------------- */
845 /* -----------------------------------------------------------------------------
848 * Approximate how much we've allocated: number of blocks in the
849 * nursery + blocks allocated via allocate() - unused nusery blocks.
850 * This leaves a little slop at the end of each block, and doesn't
851 * take into account large objects (ToDo).
852 * -------------------------------------------------------------------------- */
855 calcAllocated( void )
860 allocated = allocated_bytes();
861 allocated += countNurseryBlocks() * BLOCK_SIZE_W;
866 for (i = 0; i < n_nurseries; i++) {
868 for ( bd = capabilities[i].r.rCurrentNursery->link;
869 bd != NULL; bd = bd->link ) {
870 allocated -= BLOCK_SIZE_W;
872 cap = &capabilities[i];
873 if (cap->r.rCurrentNursery->free <
874 cap->r.rCurrentNursery->start + BLOCK_SIZE_W) {
875 allocated -= (cap->r.rCurrentNursery->start + BLOCK_SIZE_W)
876 - cap->r.rCurrentNursery->free;
880 bdescr *current_nursery = MainCapability.r.rCurrentNursery;
882 for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
883 allocated -= BLOCK_SIZE_W;
885 if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
886 allocated -= (current_nursery->start + BLOCK_SIZE_W)
887 - current_nursery->free;
892 total_allocated += allocated;
896 /* Approximate the amount of live data in the heap. To be called just
897 * after garbage collection (see GarbageCollect()).
906 if (RtsFlags.GcFlags.generations == 1) {
907 live = (g0s0->n_blocks - 1) * BLOCK_SIZE_W +
908 ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
912 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
913 for (s = 0; s < generations[g].n_steps; s++) {
914 /* approximate amount of live data (doesn't take into account slop
915 * at end of each block).
917 if (g == 0 && s == 0) {
920 stp = &generations[g].steps[s];
921 live += (stp->n_large_blocks + stp->n_blocks - 1) * BLOCK_SIZE_W;
922 if (stp->hp_bd != NULL) {
923 live += ((lnat)stp->hp_bd->free - (lnat)stp->hp_bd->start)
926 if (stp->scavd_hp != NULL) {
927 live -= (P_)(BLOCK_ROUND_UP(stp->scavd_hp)) - stp->scavd_hp;
934 /* Approximate the number of blocks that will be needed at the next
935 * garbage collection.
937 * Assume: all data currently live will remain live. Steps that will
938 * be collected next time will therefore need twice as many blocks
939 * since all the data will be copied.
948 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
949 for (s = 0; s < generations[g].n_steps; s++) {
950 if (g == 0 && s == 0) { continue; }
951 stp = &generations[g].steps[s];
952 if (generations[g].steps[0].n_blocks +
953 generations[g].steps[0].n_large_blocks
954 > generations[g].max_blocks
955 && stp->is_compacted == 0) {
956 needed += 2 * stp->n_blocks;
958 needed += stp->n_blocks;
965 /* -----------------------------------------------------------------------------
968 memInventory() checks for memory leaks by counting up all the
969 blocks we know about and comparing that to the number of blocks
970 allegedly floating around in the system.
971 -------------------------------------------------------------------------- */
976 stepBlocks (step *stp)
981 total_blocks = stp->n_blocks;
982 total_blocks += stp->n_old_blocks;
983 for (bd = stp->large_objects; bd; bd = bd->link) {
984 total_blocks += bd->blocks;
985 /* hack for megablock groups: they have an extra block or two in
986 the second and subsequent megablocks where the block
987 descriptors would normally go.
989 if (bd->blocks > BLOCKS_PER_MBLOCK) {
990 total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
991 * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
1003 lnat total_blocks = 0, free_blocks = 0;
1005 /* count the blocks we current have */
1007 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
1008 for (i = 0; i < n_capabilities; i++) {
1009 for (bd = capabilities[i].mut_lists[g]; bd != NULL; bd = bd->link) {
1010 total_blocks += bd->blocks;
1013 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
1014 total_blocks += bd->blocks;
1016 for (s = 0; s < generations[g].n_steps; s++) {
1017 if (g==0 && s==0) continue;
1018 stp = &generations[g].steps[s];
1019 total_blocks += stepBlocks(stp);
1023 for (i = 0; i < n_nurseries; i++) {
1024 total_blocks += stepBlocks(&nurseries[i]);
1027 // We put pinned object blocks in g0s0, so better count blocks there too.
1028 total_blocks += stepBlocks(g0s0);
1031 /* any blocks held by allocate() */
1032 for (bd = small_alloc_list; bd; bd = bd->link) {
1033 total_blocks += bd->blocks;
1037 if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_RETAINER) {
1038 total_blocks += retainerStackBlocks();
1042 // count the blocks allocated by the arena allocator
1043 total_blocks += arenaBlocks();
1045 /* count the blocks on the free list */
1046 free_blocks = countFreeList();
1048 if (total_blocks + free_blocks != mblocks_allocated *
1049 BLOCKS_PER_MBLOCK) {
1050 debugBelch("Blocks: %ld live + %ld free = %ld total (%ld around)\n",
1051 total_blocks, free_blocks, total_blocks + free_blocks,
1052 mblocks_allocated * BLOCKS_PER_MBLOCK);
1055 ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
1060 countBlocks(bdescr *bd)
1063 for (n=0; bd != NULL; bd=bd->link) {
1069 /* Full heap sanity check. */
1075 if (RtsFlags.GcFlags.generations == 1) {
1076 checkHeap(g0s0->blocks);
1077 checkChain(g0s0->large_objects);
1080 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
1081 for (s = 0; s < generations[g].n_steps; s++) {
1082 if (g == 0 && s == 0) { continue; }
1083 ASSERT(countBlocks(generations[g].steps[s].blocks)
1084 == generations[g].steps[s].n_blocks);
1085 ASSERT(countBlocks(generations[g].steps[s].large_objects)
1086 == generations[g].steps[s].n_large_blocks);
1087 checkHeap(generations[g].steps[s].blocks);
1088 checkChain(generations[g].steps[s].large_objects);
1090 checkMutableList(generations[g].mut_list, g);
1095 for (s = 0; s < n_nurseries; s++) {
1096 ASSERT(countBlocks(nurseries[s].blocks)
1097 == nurseries[s].n_blocks);
1098 ASSERT(countBlocks(nurseries[s].large_objects)
1099 == nurseries[s].n_large_blocks);
1102 checkFreeListSanity();
1106 /* Nursery sanity check */
1108 checkNurserySanity( step *stp )
1114 for (bd = stp->blocks; bd != NULL; bd = bd->link) {
1115 ASSERT(bd->u.back == prev);
1117 blocks += bd->blocks;
1119 ASSERT(blocks == stp->n_blocks);
1122 // handy function for use in gdb, because Bdescr() is inlined.
1123 extern bdescr *_bdescr( StgPtr p );