1 /* -----------------------------------------------------------------------------
2 * $Id: Storage.c,v 1.26 2000/07/14 13:28:35 simonmar Exp $
4 * (c) The GHC Team, 1998-1999
6 * Storage manager front end
8 * ---------------------------------------------------------------------------*/
15 #include "BlockAlloc.h"
22 #include "StoragePriv.h"
25 nat nursery_blocks; /* number of blocks in the nursery */
28 StgClosure *caf_list = NULL;
30 bdescr *small_alloc_list; /* allocate()d small objects */
31 bdescr *large_alloc_list; /* allocate()d large objects */
32 nat alloc_blocks; /* number of allocate()d blocks since GC */
33 nat alloc_blocks_lim; /* approximate limit on alloc_blocks */
35 StgPtr alloc_Hp = NULL; /* next free byte in small_alloc_list */
36 StgPtr alloc_HpLim = NULL; /* end of block at small_alloc_list */
38 generation *generations; /* all the generations */
39 generation *g0; /* generation 0, for convenience */
40 generation *oldest_gen; /* oldest generation, for convenience */
41 step *g0s0; /* generation 0, step 0, for convenience */
44 * Storage manager mutex: protects all the above state from
45 * simultaneous access by two STG threads.
48 pthread_mutex_t sm_mutex = PTHREAD_MUTEX_INITIALIZER;
54 static void *stgAllocForGMP (size_t size_in_bytes);
55 static void *stgReallocForGMP (void *ptr, size_t old_size, size_t new_size);
56 static void stgDeallocForGMP (void *ptr, size_t size);
65 /* If we're doing heap profiling, we want a two-space heap with a
66 * fixed-size allocation area so that we get roughly even-spaced
69 #if defined(PROFILING) || defined(DEBUG)
70 if (RtsFlags.ProfFlags.doHeapProfile) {
71 RtsFlags.GcFlags.generations = 1;
72 RtsFlags.GcFlags.steps = 1;
73 RtsFlags.GcFlags.oldGenFactor = 0;
74 RtsFlags.GcFlags.heapSizeSuggestion = 0;
78 if (RtsFlags.GcFlags.heapSizeSuggestion >
79 RtsFlags.GcFlags.maxHeapSize) {
80 RtsFlags.GcFlags.maxHeapSize = RtsFlags.GcFlags.heapSizeSuggestion;
85 /* allocate generation info array */
86 generations = (generation *)stgMallocBytes(RtsFlags.GcFlags.generations
87 * sizeof(struct _generation),
90 /* Initialise all generations */
91 for(g = 0; g < RtsFlags.GcFlags.generations; g++) {
92 gen = &generations[g];
94 gen->mut_list = END_MUT_LIST;
95 gen->mut_once_list = END_MUT_LIST;
97 gen->failed_promotions = 0;
101 /* A couple of convenience pointers */
102 g0 = &generations[0];
103 oldest_gen = &generations[RtsFlags.GcFlags.generations-1];
105 /* Allocate step structures in each generation */
106 if (RtsFlags.GcFlags.generations > 1) {
107 /* Only for multiple-generations */
109 /* Oldest generation: one step */
110 oldest_gen->n_steps = 1;
112 stgMallocBytes(1 * sizeof(struct _step), "initStorage: last step");
114 /* set up all except the oldest generation with 2 steps */
115 for(g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
116 generations[g].n_steps = RtsFlags.GcFlags.steps;
117 generations[g].steps =
118 stgMallocBytes (RtsFlags.GcFlags.steps * sizeof(struct _step),
119 "initStorage: steps");
123 /* single generation, i.e. a two-space collector */
125 g0->steps = stgMallocBytes (sizeof(struct _step), "initStorage: steps");
128 /* Initialise all steps */
129 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
130 for (s = 0; s < generations[g].n_steps; s++) {
131 step = &generations[g].steps[s];
135 step->gen = &generations[g];
140 step->scan_bd = NULL;
141 step->large_objects = NULL;
142 step->new_large_objects = NULL;
143 step->scavenged_large_objects = NULL;
147 /* Set up the destination pointers in each younger gen. step */
148 for (g = 0; g < RtsFlags.GcFlags.generations-1; g++) {
149 for (s = 0; s < generations[g].n_steps-1; s++) {
150 generations[g].steps[s].to = &generations[g].steps[s+1];
152 generations[g].steps[s].to = &generations[g+1].steps[0];
155 /* The oldest generation has one step and its destination is the
157 oldest_gen->steps[0].to = &oldest_gen->steps[0];
159 /* generation 0 is special: that's the nursery */
160 generations[0].max_blocks = 0;
162 /* G0S0: the allocation area. Policy: keep the allocation area
163 * small to begin with, even if we have a large suggested heap
164 * size. Reason: we're going to do a major collection first, and we
165 * don't want it to be a big one. This vague idea is borne out by
166 * rigorous experimental evidence.
168 g0s0 = &generations[0].steps[0];
172 weak_ptr_list = NULL;
175 /* initialise the allocate() interface */
176 small_alloc_list = NULL;
177 large_alloc_list = NULL;
179 alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
181 /* Tell GNU multi-precision pkg about our custom alloc functions */
182 mp_set_memory_functions(stgAllocForGMP, stgReallocForGMP, stgDeallocForGMP);
185 pthread_mutex_init(&sm_mutex, NULL);
188 IF_DEBUG(gc, stat_describe_gens());
194 stat_exit(calcAllocated());
198 /* -----------------------------------------------------------------------------
200 -------------------------------------------------------------------------- */
203 newCAF(StgClosure* caf)
205 /* Put this CAF on the mutable list for the old generation.
206 * This is a HACK - the IND_STATIC closure doesn't really have
207 * a mut_link field, but we pretend it has - in fact we re-use
208 * the STATIC_LINK field for the time being, because when we
209 * come to do a major GC we won't need the mut_link field
210 * any more and can use it as a STATIC_LINK.
212 ACQUIRE_LOCK(&sm_mutex);
214 ASSERT( ((StgMutClosure*)caf)->mut_link == NULL );
215 ((StgMutClosure *)caf)->mut_link = oldest_gen->mut_once_list;
216 oldest_gen->mut_once_list = (StgMutClosure *)caf;
219 /* If we're Hugs, we also have to put it in the CAF table, so that
220 the CAF can be reverted. When reverting, CAFs created by compiled
221 code are recorded in the CAF table, which lives outside the
222 heap, in mallocville. CAFs created by interpreted code are
223 chained together via the link fields in StgCAFs, and are not
224 recorded in the CAF table.
226 ASSERT( get_itbl(caf)->type == THUNK_STATIC );
227 addToECafTable ( caf, get_itbl(caf) );
230 RELEASE_LOCK(&sm_mutex);
235 newCAF_made_by_Hugs(StgCAF* caf)
237 ACQUIRE_LOCK(&sm_mutex);
239 ASSERT( get_itbl(caf)->type == CAF_ENTERED );
240 recordOldToNewPtrs((StgMutClosure*)caf);
241 caf->link = ecafList;
242 ecafList = caf->link;
244 RELEASE_LOCK(&sm_mutex);
249 /* These initialisations are critical for correct operation
250 on the first call of addToECafTable.
252 StgCAF* ecafList = END_ECAF_LIST;
253 StgCAFTabEntry* ecafTable = NULL;
254 StgInt usedECafTable = 0;
255 StgInt sizeECafTable = 0;
258 void clearECafTable ( void )
263 void addToECafTable ( StgClosure* closure, StgInfoTable* origItbl )
267 if (usedECafTable == sizeECafTable) {
268 /* Make the initial table size be 8 */
270 if (sizeECafTable == 0) sizeECafTable = 8;
271 et2 = stgMallocBytes (
272 sizeECafTable * sizeof(StgCAFTabEntry),
274 for (i = 0; i < usedECafTable; i++)
275 et2[i] = ecafTable[i];
276 if (ecafTable) free(ecafTable);
279 ecafTable[usedECafTable].closure = closure;
280 ecafTable[usedECafTable].origItbl = origItbl;
285 /* -----------------------------------------------------------------------------
287 -------------------------------------------------------------------------- */
290 allocNurseries( void )
299 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
300 cap->rNursery = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
301 cap->rCurrentNursery = cap->rNursery;
302 for (bd = cap->rNursery; bd != NULL; bd = bd->link) {
303 bd->back = (bdescr *)cap;
306 /* Set the back links to be equal to the Capability,
307 * so we can do slightly better informed locking.
311 nursery_blocks = RtsFlags.GcFlags.minAllocAreaSize;
312 g0s0->blocks = allocNursery(NULL, nursery_blocks);
313 g0s0->n_blocks = nursery_blocks;
314 g0s0->to_space = NULL;
315 MainRegTable.rNursery = g0s0->blocks;
316 MainRegTable.rCurrentNursery = g0s0->blocks;
317 /* hp, hpLim, hp_bd, to_space etc. aren't used in G0S0 */
322 resetNurseries( void )
328 /* All tasks must be stopped */
329 ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes);
331 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
332 for (bd = cap->rNursery; bd; bd = bd->link) {
333 bd->free = bd->start;
334 ASSERT(bd->gen == g0);
335 ASSERT(bd->step == g0s0);
336 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
338 cap->rCurrentNursery = cap->rNursery;
341 for (bd = g0s0->blocks; bd; bd = bd->link) {
342 bd->free = bd->start;
343 ASSERT(bd->gen == g0);
344 ASSERT(bd->step == g0s0);
345 IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
347 MainRegTable.rNursery = g0s0->blocks;
348 MainRegTable.rCurrentNursery = g0s0->blocks;
353 allocNursery (bdescr *last_bd, nat blocks)
358 /* Allocate a nursery */
359 for (i=0; i < blocks; i++) {
365 bd->free = bd->start;
372 resizeNursery ( nat blocks )
377 barf("resizeNursery: can't resize in SMP mode");
380 if (nursery_blocks == blocks) {
381 ASSERT(g0s0->n_blocks == blocks);
385 else if (nursery_blocks < blocks) {
386 IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n",
388 g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
394 IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n",
396 for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) {
404 g0s0->n_blocks = nursery_blocks = blocks;
407 /* -----------------------------------------------------------------------------
408 The allocate() interface
410 allocate(n) always succeeds, and returns a chunk of memory n words
411 long. n can be larger than the size of a block if necessary, in
412 which case a contiguous block group will be allocated.
413 -------------------------------------------------------------------------- */
421 ACQUIRE_LOCK(&sm_mutex);
423 TICK_ALLOC_HEAP_NOCTR(n);
426 /* big allocation (>LARGE_OBJECT_THRESHOLD) */
427 /* ToDo: allocate directly into generation 1 */
428 if (n >= LARGE_OBJECT_THRESHOLD/sizeof(W_)) {
429 nat req_blocks = (lnat)BLOCK_ROUND_UP(n*sizeof(W_)) / BLOCK_SIZE;
430 bd = allocGroup(req_blocks);
431 dbl_link_onto(bd, &g0s0->large_objects);
435 bd->free = bd->start;
436 /* don't add these blocks to alloc_blocks, since we're assuming
437 * that large objects are likely to remain live for quite a while
438 * (eg. running threads), so garbage collecting early won't make
441 alloc_blocks += req_blocks;
442 RELEASE_LOCK(&sm_mutex);
445 /* small allocation (<LARGE_OBJECT_THRESHOLD) */
446 } else if (small_alloc_list == NULL || alloc_Hp + n > alloc_HpLim) {
447 if (small_alloc_list) {
448 small_alloc_list->free = alloc_Hp;
451 bd->link = small_alloc_list;
452 small_alloc_list = bd;
456 alloc_Hp = bd->start;
457 alloc_HpLim = bd->start + BLOCK_SIZE_W;
463 RELEASE_LOCK(&sm_mutex);
467 lnat allocated_bytes(void)
469 return (alloc_blocks * BLOCK_SIZE_W - (alloc_HpLim - alloc_Hp));
472 /* -----------------------------------------------------------------------------
473 Allocation functions for GMP.
475 These all use the allocate() interface - we can't have any garbage
476 collection going on during a gmp operation, so we use allocate()
477 which always succeeds. The gmp operations which might need to
478 allocate will ask the storage manager (via doYouWantToGC()) whether
479 a garbage collection is required, in case we get into a loop doing
480 only allocate() style allocation.
481 -------------------------------------------------------------------------- */
484 stgAllocForGMP (size_t size_in_bytes)
487 nat data_size_in_words, total_size_in_words;
489 /* should be a multiple of sizeof(StgWord) (whole no. of limbs) */
490 ASSERT(size_in_bytes % sizeof(W_) == 0);
492 data_size_in_words = size_in_bytes / sizeof(W_);
493 total_size_in_words = sizeofW(StgArrWords) + data_size_in_words;
495 /* allocate and fill it in. */
496 arr = (StgArrWords *)allocate(total_size_in_words);
497 SET_ARR_HDR(arr, &ARR_WORDS_info, CCCS, data_size_in_words);
499 /* and return a ptr to the goods inside the array */
500 return(BYTE_ARR_CTS(arr));
504 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
506 void *new_stuff_ptr = stgAllocForGMP(new_size);
508 char *p = (char *) ptr;
509 char *q = (char *) new_stuff_ptr;
511 for (; i < old_size; i++, p++, q++) {
515 return(new_stuff_ptr);
519 stgDeallocForGMP (void *ptr STG_UNUSED,
520 size_t size STG_UNUSED)
522 /* easy for us: the garbage collector does the dealloc'n */
525 /* -----------------------------------------------------------------------------
527 * -------------------------------------------------------------------------- */
529 /* -----------------------------------------------------------------------------
532 * Approximate how much we've allocated: number of blocks in the
533 * nursery + blocks allocated via allocate() - unused nusery blocks.
534 * This leaves a little slop at the end of each block, and doesn't
535 * take into account large objects (ToDo).
536 * -------------------------------------------------------------------------- */
539 calcAllocated( void )
547 /* All tasks must be stopped. Can't assert that all the
548 capabilities are owned by the scheduler, though: one or more
549 tasks might have been stopped while they were running (non-main)
551 /* ASSERT(n_free_capabilities == RtsFlags.ParFlags.nNodes); */
554 n_free_capabilities * RtsFlags.GcFlags.minAllocAreaSize * BLOCK_SIZE_W
557 for (cap = free_capabilities; cap != NULL; cap = cap->link) {
558 for ( bd = cap->rCurrentNursery->link; bd != NULL; bd = bd->link ) {
559 allocated -= BLOCK_SIZE_W;
561 if (cap->rCurrentNursery->free < cap->rCurrentNursery->start
563 allocated -= (cap->rCurrentNursery->start + BLOCK_SIZE_W)
564 - cap->rCurrentNursery->free;
569 bdescr *current_nursery = MainRegTable.rCurrentNursery;
571 allocated = (nursery_blocks * BLOCK_SIZE_W) + allocated_bytes();
572 for ( bd = current_nursery->link; bd != NULL; bd = bd->link ) {
573 allocated -= BLOCK_SIZE_W;
575 if (current_nursery->free < current_nursery->start + BLOCK_SIZE_W) {
576 allocated -= (current_nursery->start + BLOCK_SIZE_W)
577 - current_nursery->free;
584 /* Approximate the amount of live data in the heap. To be called just
585 * after garbage collection (see GarbageCollect()).
594 if (RtsFlags.GcFlags.generations == 1) {
595 live = (g0s0->to_blocks - 1) * BLOCK_SIZE_W +
596 ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
600 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
601 for (s = 0; s < generations[g].n_steps; s++) {
602 /* approximate amount of live data (doesn't take into account slop
603 * at end of each block).
605 if (g == 0 && s == 0) {
608 step = &generations[g].steps[s];
609 live += (step->n_blocks - 1) * BLOCK_SIZE_W +
610 ((lnat)step->hp_bd->free - (lnat)step->hp_bd->start) / sizeof(W_);
616 /* Approximate the number of blocks that will be needed at the next
617 * garbage collection.
619 * Assume: all data currently live will remain live. Steps that will
620 * be collected next time will therefore need twice as many blocks
621 * since all the data will be copied.
630 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
631 for (s = 0; s < generations[g].n_steps; s++) {
632 if (g == 0 && s == 0) { continue; }
633 step = &generations[g].steps[s];
634 if (generations[g].steps[0].n_blocks > generations[g].max_blocks) {
635 needed += 2 * step->n_blocks;
637 needed += step->n_blocks;
644 /* -----------------------------------------------------------------------------
647 memInventory() checks for memory leaks by counting up all the
648 blocks we know about and comparing that to the number of blocks
649 allegedly floating around in the system.
650 -------------------------------------------------------------------------- */
660 lnat total_blocks = 0, free_blocks = 0;
662 /* count the blocks we current have */
664 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
665 for (s = 0; s < generations[g].n_steps; s++) {
666 step = &generations[g].steps[s];
667 total_blocks += step->n_blocks;
668 if (RtsFlags.GcFlags.generations == 1) {
669 /* two-space collector has a to-space too :-) */
670 total_blocks += g0s0->to_blocks;
672 for (bd = step->large_objects; bd; bd = bd->link) {
673 total_blocks += bd->blocks;
674 /* hack for megablock groups: they have an extra block or two in
675 the second and subsequent megablocks where the block
676 descriptors would normally go.
678 if (bd->blocks > BLOCKS_PER_MBLOCK) {
679 total_blocks -= (MBLOCK_SIZE / BLOCK_SIZE - BLOCKS_PER_MBLOCK)
680 * (bd->blocks/(MBLOCK_SIZE/BLOCK_SIZE));
686 /* any blocks held by allocate() */
687 for (bd = small_alloc_list; bd; bd = bd->link) {
688 total_blocks += bd->blocks;
690 for (bd = large_alloc_list; bd; bd = bd->link) {
691 total_blocks += bd->blocks;
694 /* count the blocks on the free list */
695 free_blocks = countFreeList();
697 ASSERT(total_blocks + free_blocks == mblocks_allocated * BLOCKS_PER_MBLOCK);
700 if (total_blocks + free_blocks != mblocks_allocated *
702 fprintf(stderr, "Blocks: %ld live + %ld free = %ld total (%ld around)\n",
703 total_blocks, free_blocks, total_blocks + free_blocks,
704 mblocks_allocated * BLOCKS_PER_MBLOCK);
709 /* Full heap sanity check. */
716 if (RtsFlags.GcFlags.generations == 1) {
717 checkHeap(g0s0->to_space, NULL);
718 checkChain(g0s0->large_objects);
721 for (g = 0; g <= N; g++) {
722 for (s = 0; s < generations[g].n_steps; s++) {
723 if (g == 0 && s == 0) { continue; }
724 checkHeap(generations[g].steps[s].blocks, NULL);
727 for (g = N+1; g < RtsFlags.GcFlags.generations; g++) {
728 for (s = 0; s < generations[g].n_steps; s++) {
729 checkHeap(generations[g].steps[s].blocks,
730 generations[g].steps[s].blocks->start);
731 checkChain(generations[g].steps[s].large_objects);
734 checkFreeListSanity();