X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FGC.c;h=cc1c7973cc5c63220491480327e667599fbcdeb6;hb=c0eea9160807127a1c0ff08374c61f2e667755d5;hp=937a356dc09022c1e2ab7b0ce70c5e32a67830dd;hpb=a55ddbd63ef4ff75be8577767248a70c49529190;p=ghc-hetmet.git diff --git a/ghc/rts/GC.c b/ghc/rts/GC.c index 937a356..cc1c797 100644 --- a/ghc/rts/GC.c +++ b/ghc/rts/GC.c @@ -1,7 +1,9 @@ /* ----------------------------------------------------------------------------- - * $Id: GC.c,v 1.16 1999/01/19 17:22:55 simonm Exp $ + * $Id: GC.c,v 1.47 1999/03/03 18:58:53 sof Exp $ * - * Two-space garbage collector + * (c) The GHC Team 1998-1999 + * + * Generational garbage collector * * ---------------------------------------------------------------------------*/ @@ -20,6 +22,7 @@ #include "DebugProf.h" #include "SchedAPI.h" #include "Weak.h" +#include "StablePriv.h" StgCAF* enteredCAFs; @@ -88,24 +91,32 @@ static rtsBool failed_to_evac; */ bdescr *old_to_space; +/* Data used for allocation area sizing. + */ +lnat new_blocks; /* blocks allocated during this GC */ +lnat g0s0_pcnt_kept = 30; /* percentage of g0s0 live at last minor GC */ + /* ----------------------------------------------------------------------------- Static function declarations -------------------------------------------------------------------------- */ -static StgClosure *evacuate(StgClosure *q); -static void zeroStaticObjectList(StgClosure* first_static); -static rtsBool traverse_weak_ptr_list(void); -static void zeroMutableList(StgMutClosure *first); -static void revertDeadCAFs(void); +static StgClosure * evacuate ( StgClosure *q ); +static void zero_static_object_list ( StgClosure* first_static ); +static void zero_mutable_list ( StgMutClosure *first ); +static void revert_dead_CAFs ( void ); + +static rtsBool traverse_weak_ptr_list ( void ); +static void cleanup_weak_ptr_list ( void ); -static void scavenge_stack(StgPtr p, StgPtr stack_end); -static void scavenge_large(step *step); -static void scavenge(step *step); -static void scavenge_static(void); -static StgMutClosure *scavenge_mutable_list(StgMutClosure *p, nat gen); +static void scavenge_stack ( StgPtr p, StgPtr stack_end ); +static void scavenge_large ( step *step ); +static void scavenge ( step *step ); +static void scavenge_static ( void ); +static void scavenge_mutable_list ( generation *g ); +static void scavenge_mut_once_list ( generation *g ); #ifdef DEBUG -static void gcCAFs(void); +static void gcCAFs ( void ); #endif /* ----------------------------------------------------------------------------- @@ -135,7 +146,7 @@ void GarbageCollect(void (*get_roots)(void)) { bdescr *bd; step *step; - lnat live, allocated, collected = 0; + lnat live, allocated, collected = 0, copied = 0; nat g, s; #ifdef PROFILING @@ -187,10 +198,10 @@ void GarbageCollect(void (*get_roots)(void)) scavenged_static_objects = END_OF_STATIC_LIST; /* zero the mutable list for the oldest generation (see comment by - * zeroMutableList below). + * zero_mutable_list below). */ if (major_gc) { - zeroMutableList(generations[RtsFlags.GcFlags.generations-1].mut_list); + zero_mutable_list(generations[RtsFlags.GcFlags.generations-1].mut_once_list); } /* Save the old to-space if we're doing a two-space collection @@ -200,10 +211,16 @@ void GarbageCollect(void (*get_roots)(void)) g0s0->to_space = NULL; } + /* Keep a count of how many new blocks we allocated during this GC + * (used for resizing the allocation area, later). + */ + new_blocks = 0; + /* Initialise to-space in all the generations/steps that we're * collecting. */ for (g = 0; g <= N; g++) { + generations[g].mut_once_list = END_MUT_LIST; generations[g].mut_list = END_MUT_LIST; for (s = 0; s < generations[g].n_steps; s++) { @@ -228,11 +245,12 @@ void GarbageCollect(void (*get_roots)(void)) step->hpLim = step->hp + BLOCK_SIZE_W; step->hp_bd = bd; step->to_space = bd; - step->to_blocks = 1; /* ???? */ + step->to_blocks = 1; step->scan = bd->start; step->scan_bd = bd; step->new_large_objects = NULL; step->scavenged_large_objects = NULL; + new_blocks++; /* mark the large objects as not evacuated yet */ for (bd = step->large_objects; bd; bd = bd->link) { bd->evacuated = 0; @@ -257,6 +275,7 @@ void GarbageCollect(void (*get_roots)(void)) step->hp_bd = bd; step->blocks = bd; step->n_blocks = 1; + new_blocks++; } /* Set the scan pointer for older generations: remember we * still have to scavenge objects that have been promoted. */ @@ -282,19 +301,27 @@ void GarbageCollect(void (*get_roots)(void)) * it has already been evaced to gen 2. */ { - StgMutClosure *tmp, **pp; - for (g = N+1; g < RtsFlags.GcFlags.generations; g++) { + int st; + for (g = RtsFlags.GcFlags.generations-1; g > N; g--) { generations[g].saved_mut_list = generations[g].mut_list; generations[g].mut_list = END_MUT_LIST; } + /* Do the mut-once lists first */ for (g = RtsFlags.GcFlags.generations-1; g > N; g--) { - tmp = scavenge_mutable_list(generations[g].saved_mut_list, g); - pp = &generations[g].mut_list; - while (*pp != END_MUT_LIST) { - pp = &(*pp)->mut_link; + scavenge_mut_once_list(&generations[g]); + evac_gen = g; + for (st = generations[g].n_steps-1; st >= 0; st--) { + scavenge(&generations[g].steps[st]); + } + } + + for (g = RtsFlags.GcFlags.generations-1; g > N; g--) { + scavenge_mutable_list(&generations[g]); + evac_gen = g; + for (st = generations[g].n_steps-1; st >= 0; st--) { + scavenge(&generations[g].steps[st]); } - *pp = tmp; } } @@ -312,11 +339,14 @@ void GarbageCollect(void (*get_roots)(void)) /* Mark the weak pointer list, and prepare to detect dead weak * pointers. */ - markWeakList(); old_weak_ptr_list = weak_ptr_list; weak_ptr_list = NULL; weak_done = rtsFalse; + /* Mark the stable pointer table. + */ + markStablePtrTable(major_gc); + #ifdef INTERPRETER { /* ToDo: To fix the caf leak, we need to make the commented out @@ -331,7 +361,7 @@ void GarbageCollect(void (*get_roots)(void)) */ scavengeEverything(); /* revert dead CAFs and update enteredCAFs list */ - revertDeadCAFs(); + revert_dead_CAFs(); #endif markHugsObjects(); #if 0 @@ -368,18 +398,24 @@ void GarbageCollect(void (*get_roots)(void)) /* scavenge each step in generations 0..maxgen */ { - int gen; + int gen, st; + loop2: for (gen = RtsFlags.GcFlags.generations-1; gen >= 0; gen--) { - for (s = 0; s < generations[gen].n_steps; s++) { - step = &generations[gen].steps[s]; + for (st = generations[gen].n_steps-1; st >= 0 ; st--) { + if (gen == 0 && st == 0 && RtsFlags.GcFlags.generations > 1) { + continue; + } + step = &generations[gen].steps[st]; evac_gen = gen; if (step->hp_bd != step->scan_bd || step->scan < step->hp) { scavenge(step); flag = rtsTrue; + goto loop2; } if (step->new_large_objects != NULL) { scavenge_large(step); flag = rtsTrue; + goto loop2; } } } @@ -392,6 +428,15 @@ void GarbageCollect(void (*get_roots)(void)) } } + /* Final traversal of the weak pointer list (see comment by + * cleanUpWeakPtrList below). + */ + cleanup_weak_ptr_list(); + + /* Now see which stable names are still alive. + */ + gcStablePtrTable(major_gc); + /* Set the maximum blocks for the oldest generation, based on twice * the amount of live data now, adjusted to fit the maximum heap * size if necessary. @@ -411,69 +456,15 @@ void GarbageCollect(void (*get_roots)(void)) (int)oldest_gen->steps[0].to_blocks) < (RtsFlags.GcFlags.pcFreeHeap * RtsFlags.GcFlags.maxHeapSize / 200)) { + heapOverflow(); } } } - } else { - /* For a two-space collector, we need to resize the nursery. */ - - /* set up a new nursery. Allocate a nursery size based on a - * function of the amount of live data (currently a factor of 2, - * should be configurable (ToDo)). Use the blocks from the old - * nursery if possible, freeing up any left over blocks. - * - * If we get near the maximum heap size, then adjust our nursery - * size accordingly. If the nursery is the same size as the live - * data (L), then we need 3L bytes. We can reduce the size of the - * nursery to bring the required memory down near 2L bytes. - * - * A normal 2-space collector would need 4L bytes to give the same - * performance we get from 3L bytes, reducing to the same - * performance at 2L bytes. - */ - nat blocks = g0s0->to_blocks; - - if ( blocks * 4 > RtsFlags.GcFlags.maxHeapSize ) { - int adjusted_blocks; /* signed on purpose */ - int pc_free; - - adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks); - IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks)); - pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize; - if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ { - heapOverflow(); - } - blocks = adjusted_blocks; - - } else { - blocks *= 2; - if (blocks < RtsFlags.GcFlags.minAllocAreaSize) { - blocks = RtsFlags.GcFlags.minAllocAreaSize; - } - } - - if (nursery_blocks < blocks) { - IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n", - blocks)); - g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks); - } else { - bdescr *next_bd; - - IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n", - blocks)); - for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) { - next_bd = bd->link; - freeGroup(bd); - bd = next_bd; - } - g0s0->blocks = bd; - } - - g0s0->n_blocks = nursery_blocks = blocks; } /* run through all the generations/steps and tidy up */ + copied = new_blocks * BLOCK_SIZE_W; for (g = 0; g < RtsFlags.GcFlags.generations; g++) { if (g <= N) { @@ -488,6 +479,11 @@ void GarbageCollect(void (*get_roots)(void)) /* Tidy the end of the to-space chains */ step->hp_bd->free = step->hp; step->hp_bd->link = NULL; + /* stats information: how much we copied */ + if (g <= N) { + copied -= step->hp_bd->start + BLOCK_SIZE_W - + step->hp_bd->free; + } } /* for generations we collected... */ @@ -529,16 +525,16 @@ void GarbageCollect(void (*get_roots)(void)) * between the maximum size of the oldest and youngest * generations. * - * max_blocks = alloc_area_size + - * (oldgen_max_blocks - alloc_area_size) * G - * ----------------------------------------- - * oldest_gen + * max_blocks = oldgen_max_blocks * G + * ---------------------- + * oldest_gen */ if (g != 0) { - generations[g].max_blocks = - RtsFlags.GcFlags.minAllocAreaSize + - (((oldest_gen->max_blocks - RtsFlags.GcFlags.minAllocAreaSize) * g) - / (RtsFlags.GcFlags.generations-1)); +#if 0 + generations[g].max_blocks = (oldest_gen->max_blocks * g) + / (RtsFlags.GcFlags.generations-1); +#endif + generations[g].max_blocks = oldest_gen->max_blocks; } /* for older generations... */ @@ -560,39 +556,117 @@ void GarbageCollect(void (*get_roots)(void)) } } + /* Guess the amount of live data for stats. */ + live = calcLive(); + + /* Free the small objects allocated via allocate(), since this will + * all have been copied into G0S1 now. + */ + if (small_alloc_list != NULL) { + freeChain(small_alloc_list); + } + small_alloc_list = NULL; + alloc_blocks = 0; + alloc_Hp = NULL; + alloc_HpLim = NULL; + alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize; + /* Two-space collector: * Free the old to-space, and estimate the amount of live data. */ if (RtsFlags.GcFlags.generations == 1) { + nat blocks; + if (old_to_space != NULL) { freeChain(old_to_space); } for (bd = g0s0->to_space; bd != NULL; bd = bd->link) { bd->evacuated = 0; /* now from-space */ } - live = g0s0->to_blocks * BLOCK_SIZE_W + - ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_); - /* Generational collector: - * estimate the amount of live data. - */ + /* For a two-space collector, we need to resize the nursery. */ + + /* set up a new nursery. Allocate a nursery size based on a + * function of the amount of live data (currently a factor of 2, + * should be configurable (ToDo)). Use the blocks from the old + * nursery if possible, freeing up any left over blocks. + * + * If we get near the maximum heap size, then adjust our nursery + * size accordingly. If the nursery is the same size as the live + * data (L), then we need 3L bytes. We can reduce the size of the + * nursery to bring the required memory down near 2L bytes. + * + * A normal 2-space collector would need 4L bytes to give the same + * performance we get from 3L bytes, reducing to the same + * performance at 2L bytes. + */ + blocks = g0s0->to_blocks; + + if ( blocks * RtsFlags.GcFlags.oldGenFactor * 2 > + RtsFlags.GcFlags.maxHeapSize ) { + int adjusted_blocks; /* signed on purpose */ + int pc_free; + + adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks); + IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks)); + pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize; + if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ { + heapOverflow(); + } + blocks = adjusted_blocks; + + } else { + blocks *= RtsFlags.GcFlags.oldGenFactor; + if (blocks < RtsFlags.GcFlags.minAllocAreaSize) { + blocks = RtsFlags.GcFlags.minAllocAreaSize; + } + } + resizeNursery(blocks); + } else { - live = 0; - for (g = 0; g < RtsFlags.GcFlags.generations; g++) { - for (s = 0; s < generations[g].n_steps; s++) { - /* approximate amount of live data (doesn't take into account slop - * at end of each block). ToDo: this more accurately. - */ - if (g == 0 && s == 0) { continue; } - step = &generations[g].steps[s]; - live += step->n_blocks * BLOCK_SIZE_W + - ((lnat)step->hp_bd->free -(lnat)step->hp_bd->start) / sizeof(W_); + /* Generational collector: + * If the user has given us a suggested heap size, adjust our + * allocation area to make best use of the memory available. + */ + + if (RtsFlags.GcFlags.heapSizeSuggestion) { + int blocks; + nat needed = calcNeeded(); /* approx blocks needed at next GC */ + + /* Guess how much will be live in generation 0 step 0 next time. + * A good approximation is the obtained by finding the + * percentage of g0s0 that was live at the last minor GC. + */ + if (N == 0) { + g0s0_pcnt_kept = (new_blocks * 100) / g0s0->n_blocks; + } + + /* Estimate a size for the allocation area based on the + * information available. We might end up going slightly under + * or over the suggested heap size, but we should be pretty + * close on average. + * + * Formula: suggested - needed + * ---------------------------- + * 1 + g0s0_pcnt_kept/100 + * + * where 'needed' is the amount of memory needed at the next + * collection for collecting all steps except g0s0. + */ + blocks = + (((int)RtsFlags.GcFlags.heapSizeSuggestion - (int)needed) * 100) / + (100 + (int)g0s0_pcnt_kept); + + if (blocks < (int)RtsFlags.GcFlags.minAllocAreaSize) { + blocks = RtsFlags.GcFlags.minAllocAreaSize; } + + resizeNursery((nat)blocks); } } /* revert dead CAFs and update enteredCAFs list */ - revertDeadCAFs(); + revert_dead_CAFs(); /* mark the garbage collected CAFs as dead */ #ifdef DEBUG @@ -601,7 +675,7 @@ void GarbageCollect(void (*get_roots)(void)) /* zero the scavenged static object list */ if (major_gc) { - zeroStaticObjectList(scavenged_static_objects); + zero_static_object_list(scavenged_static_objects); } /* Reset the nursery @@ -610,46 +684,17 @@ void GarbageCollect(void (*get_roots)(void)) bd->free = bd->start; ASSERT(bd->gen == g0); ASSERT(bd->step == g0s0); + IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE)); } current_nursery = g0s0->blocks; - /* Free the small objects allocated via allocate(), since this will - * all have been copied into G0S1 now. - */ - if (small_alloc_list != NULL) { - freeChain(small_alloc_list); - } - small_alloc_list = NULL; - alloc_blocks = 0; - alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize; - - /* start any pending finalisers */ - scheduleFinalisers(old_weak_ptr_list); + /* start any pending finalizers */ + scheduleFinalizers(old_weak_ptr_list); /* check sanity after GC */ -#ifdef DEBUG - if (RtsFlags.GcFlags.generations == 1) { - IF_DEBUG(sanity, checkHeap(g0s0->to_space, NULL)); - IF_DEBUG(sanity, checkChain(g0s0->large_objects)); - } else { - - for (g = 0; g <= N; g++) { - for (s = 0; s < generations[g].n_steps; s++) { - if (g == 0 && s == 0) { continue; } - IF_DEBUG(sanity, checkHeap(generations[g].steps[s].blocks, NULL)); - } - } - for (g = N+1; g < RtsFlags.GcFlags.generations; g++) { - for (s = 0; s < generations[g].n_steps; s++) { - IF_DEBUG(sanity, checkHeap(generations[g].steps[s].blocks, - generations[g].steps[s].blocks->start)); - IF_DEBUG(sanity, checkChain(generations[g].steps[s].large_objects)); - } - } - IF_DEBUG(sanity, checkFreeListSanity()); - } -#endif + IF_DEBUG(sanity, checkSanity(N)); + /* extra GC trace info */ IF_DEBUG(gc, stat_describe_gens()); #ifdef DEBUG @@ -666,7 +711,7 @@ void GarbageCollect(void (*get_roots)(void)) IF_DEBUG(sanity, memInventory()); /* ok, GC over: tell the stats department what happened. */ - stat_endGC(allocated, collected, live, N); + stat_endGC(allocated, collected, live, copied, N); } /* ----------------------------------------------------------------------------- @@ -683,7 +728,7 @@ void GarbageCollect(void (*get_roots)(void)) new live weak pointers, then all the currently unreachable ones are dead. - For generational GC: we just don't try to finalise weak pointers in + For generational GC: we just don't try to finalize weak pointers in older generations than the one we're collecting. This could probably be optimised by keeping per-generation lists of weak pointers, but for a few weak pointers this scheme will work. @@ -693,80 +738,70 @@ static rtsBool traverse_weak_ptr_list(void) { StgWeak *w, **last_w, *next_w; - StgClosure *target; - const StgInfoTable *info; + StgClosure *new; rtsBool flag = rtsFalse; if (weak_done) { return rtsFalse; } - /* doesn't matter where we evacuate values/finalisers to, since + /* doesn't matter where we evacuate values/finalizers to, since * these pointers are treated as roots (iff the keys are alive). */ evac_gen = 0; last_w = &old_weak_ptr_list; for (w = old_weak_ptr_list; w; w = next_w) { - target = w->key; - loop: - /* ignore weak pointers in older generations */ - if (!LOOKS_LIKE_STATIC(target) && Bdescr((P_)target)->gen->no > N) { - IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive (in old gen) at %p\n", w)); - /* remove this weak ptr from the old_weak_ptr list */ - *last_w = w->link; - /* and put it on the new weak ptr list */ - next_w = w->link; - w->link = weak_ptr_list; - weak_ptr_list = w; - flag = rtsTrue; + + /* First, this weak pointer might have been evacuated. If so, + * remove the forwarding pointer from the weak_ptr_list. + */ + if (get_itbl(w)->type == EVACUATED) { + w = (StgWeak *)((StgEvacuated *)w)->evacuee; + *last_w = w; + } + + /* There might be a DEAD_WEAK on the list if finalizeWeak# was + * called on a live weak pointer object. Just remove it. + */ + if (w->header.info == &DEAD_WEAK_info) { + next_w = ((StgDeadWeak *)w)->link; + *last_w = next_w; continue; } - info = get_itbl(target); - switch (info->type) { - - case IND: - case IND_STATIC: - case IND_PERM: - case IND_OLDGEN: /* rely on compatible layout with StgInd */ - case IND_OLDGEN_PERM: - /* follow indirections */ - target = ((StgInd *)target)->indirectee; - goto loop; + ASSERT(get_itbl(w)->type == WEAK); - case EVACUATED: - /* If key is alive, evacuate value and finaliser and - * place weak ptr on new weak ptr list. - */ - IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive at %p\n", w)); - w->key = ((StgEvacuated *)target)->evacuee; + /* Now, check whether the key is reachable. + */ + if ((new = isAlive(w->key))) { + w->key = new; + /* evacuate the value and finalizer */ w->value = evacuate(w->value); - w->finaliser = evacuate(w->finaliser); - + w->finalizer = evacuate(w->finalizer); /* remove this weak ptr from the old_weak_ptr list */ *last_w = w->link; - /* and put it on the new weak ptr list */ next_w = w->link; w->link = weak_ptr_list; weak_ptr_list = w; flag = rtsTrue; - break; - - default: /* key is dead */ + IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive at %p -> %p\n", w, w->key)); + continue; + } + else { last_w = &(w->link); next_w = w->link; - break; + continue; } } /* If we didn't make any changes, then we can go round and kill all * the dead weak pointers. The old_weak_ptr list is used as a list - * of pending finalisers later on. + * of pending finalizers later on. */ if (flag == rtsFalse) { for (w = old_weak_ptr_list; w; w = w->link) { w->value = evacuate(w->value); - w->finaliser = evacuate(w->finaliser); + w->finalizer = evacuate(w->finalizer); } weak_done = rtsTrue; } @@ -774,14 +809,93 @@ traverse_weak_ptr_list(void) return rtsTrue; } +/* ----------------------------------------------------------------------------- + After GC, the live weak pointer list may have forwarding pointers + on it, because a weak pointer object was evacuated after being + moved to the live weak pointer list. We remove those forwarding + pointers here. + + Also, we don't consider weak pointer objects to be reachable, but + we must nevertheless consider them to be "live" and retain them. + Therefore any weak pointer objects which haven't as yet been + evacuated need to be evacuated now. + -------------------------------------------------------------------------- */ + +static void +cleanup_weak_ptr_list ( void ) +{ + StgWeak *w, **last_w; + + last_w = &weak_ptr_list; + for (w = weak_ptr_list; w; w = w->link) { + + if (get_itbl(w)->type == EVACUATED) { + w = (StgWeak *)((StgEvacuated *)w)->evacuee; + *last_w = w; + } + + if (Bdescr((P_)w)->evacuated == 0) { + (StgClosure *)w = evacuate((StgClosure *)w); + *last_w = w; + } + last_w = &(w->link); + } +} + +/* ----------------------------------------------------------------------------- + isAlive determines whether the given closure is still alive (after + a garbage collection) or not. It returns the new address of the + closure if it is alive, or NULL otherwise. + -------------------------------------------------------------------------- */ + +StgClosure * +isAlive(StgClosure *p) +{ + StgInfoTable *info; + + while (1) { + + info = get_itbl(p); + + /* ToDo: for static closures, check the static link field. + * Problem here is that we sometimes don't set the link field, eg. + * for static closures with an empty SRT or CONSTR_STATIC_NOCAFs. + */ + + /* ignore closures in generations that we're not collecting. */ + if (LOOKS_LIKE_STATIC(p) || Bdescr((P_)p)->gen->no > N) { + return p; + } + + switch (info->type) { + + case IND: + case IND_STATIC: + case IND_PERM: + case IND_OLDGEN: /* rely on compatible layout with StgInd */ + case IND_OLDGEN_PERM: + /* follow indirections */ + p = ((StgInd *)p)->indirectee; + continue; + + case EVACUATED: + /* alive! */ + return ((StgEvacuated *)p)->evacuee; + + default: + /* dead. */ + return NULL; + } + } +} + StgClosure * MarkRoot(StgClosure *root) { - root = evacuate(root); - return root; + return evacuate(root); } -static inline void addBlock(step *step) +static void addBlock(step *step) { bdescr *bd = allocBlock(); bd->gen = step->gen; @@ -799,22 +913,33 @@ static inline void addBlock(step *step) step->hpLim = step->hp + BLOCK_SIZE_W; step->hp_bd = bd; step->to_blocks++; + new_blocks++; +} + +static __inline__ void +upd_evacuee(StgClosure *p, StgClosure *dest) +{ + p->header.info = &EVACUATED_info; + ((StgEvacuated *)p)->evacuee = dest; } static __inline__ StgClosure * -copy(StgClosure *src, nat size, bdescr *bd) +copy(StgClosure *src, nat size, step *step) { - step *step; P_ to, from, dest; + TICK_GC_WORDS_COPIED(size); /* Find out where we're going, using the handy "to" pointer in * the step of the source object. If it turns out we need to * evacuate to an older generation, adjust it here (see comment * by evacuate()). */ - step = bd->step->to; if (step->gen->no < evac_gen) { +#ifdef NO_EAGER_PROMOTION + failed_to_evac = rtsTrue; +#else step = &generations[evac_gen].steps[0]; +#endif } /* chain a new block onto the to-space for the destination step if @@ -824,11 +949,13 @@ copy(StgClosure *src, nat size, bdescr *bd) addBlock(step); } - dest = step->hp; - step->hp += size; - for(to = dest, from = (P_)src; size>0; --size) { + for(to = step->hp, from = (P_)src; size>0; --size) { *to++ = *from++; } + + dest = step->hp; + step->hp = to; + upd_evacuee(src,(StgClosure *)dest); return (StgClosure *)dest; } @@ -838,57 +965,33 @@ copy(StgClosure *src, nat size, bdescr *bd) */ static __inline__ StgClosure * -copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, bdescr *bd) +copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, step *step) { - step *step; P_ dest, to, from; - step = bd->step->to; + TICK_GC_WORDS_COPIED(size_to_copy); if (step->gen->no < evac_gen) { +#ifdef NO_EAGER_PROMOTION + failed_to_evac = rtsTrue; +#else step = &generations[evac_gen].steps[0]; +#endif } if (step->hp + size_to_reserve >= step->hpLim) { addBlock(step); } - dest = step->hp; - step->hp += size_to_reserve; - for(to = dest, from = (P_)src; size_to_copy>0; --size_to_copy) { + for(to = step->hp, from = (P_)src; size_to_copy>0; --size_to_copy) { *to++ = *from++; } + dest = step->hp; + step->hp += size_to_reserve; + upd_evacuee(src,(StgClosure *)dest); return (StgClosure *)dest; } -static __inline__ void -upd_evacuee(StgClosure *p, StgClosure *dest) -{ - StgEvacuated *q = (StgEvacuated *)p; - - SET_INFO(q,&EVACUATED_info); - q->evacuee = dest; -} - -/* ----------------------------------------------------------------------------- - Evacuate a mutable object - - If we evacuate a mutable object to an old generation, cons the - object onto the older generation's mutable list. - -------------------------------------------------------------------------- */ - -static inline void -evacuate_mutable(StgMutClosure *c) -{ - bdescr *bd; - - bd = Bdescr((P_)c); - if (bd->gen->no > 0) { - c->mut_link = bd->gen->mut_list; - bd->gen->mut_list = c; - } -} - /* ----------------------------------------------------------------------------- Evacuate a large object @@ -916,6 +1019,7 @@ evacuate_large(StgPtr p, rtsBool mutable) */ if (bd->gen->no < evac_gen) { failed_to_evac = rtsTrue; + TICK_GC_FAILED_PROMOTION(); } return; } @@ -935,7 +1039,11 @@ evacuate_large(StgPtr p, rtsBool mutable) */ step = bd->step->to; if (step->gen->no < evac_gen) { +#ifdef NO_EAGER_PROMOTION + failed_to_evac = rtsTrue; +#else step = &generations[evac_gen].steps[0]; +#endif } bd->step = step; @@ -945,7 +1053,7 @@ evacuate_large(StgPtr p, rtsBool mutable) bd->evacuated = 1; if (mutable) { - evacuate_mutable((StgMutClosure *)p); + recordMutable((StgMutClosure *)p); } } @@ -977,7 +1085,7 @@ mkMutCons(StgClosure *ptr, generation *gen) SET_HDR(q,&MUT_CONS_info,CCS_GC); q->var = ptr; - evacuate_mutable((StgMutClosure *)q); + recordOldToNewPtrs((StgMutClosure *)q); return (StgClosure *)q; } @@ -1013,10 +1121,11 @@ evacuate(StgClosure *q) { StgClosure *to; bdescr *bd = NULL; + step *step; const StgInfoTable *info; loop: - if (!LOOKS_LIKE_STATIC(q)) { + if (HEAP_ALLOCED(q)) { bd = Bdescr((P_)q); if (bd->gen->no > N) { /* Can't evacuate this object, because it's in a generation @@ -1026,9 +1135,11 @@ loop: if (bd->gen->no < evac_gen) { /* nope */ failed_to_evac = rtsTrue; + TICK_GC_FAILED_PROMOTION(); } return q; } + step = bd->step->to; } /* make sure the info pointer is into text space */ @@ -1039,17 +1150,43 @@ loop: switch (info -> type) { case BCO: - to = copy(q,bco_sizeW(stgCast(StgBCO*,q)),bd); - upd_evacuee(q,to); - return to; + return copy(q,bco_sizeW(stgCast(StgBCO*,q)),step); case MUT_VAR: + ASSERT(q->header.info != &MUT_CONS_info); case MVAR: - to = copy(q,sizeW_fromITBL(info),bd); - upd_evacuee(q,to); - evacuate_mutable((StgMutClosure *)to); + to = copy(q,sizeW_fromITBL(info),step); + recordMutable((StgMutClosure *)to); return to; + case FUN_1_0: + case FUN_0_1: + case CONSTR_1_0: + case CONSTR_0_1: + return copy(q,sizeofW(StgHeader)+1,step); + + case THUNK_1_0: /* here because of MIN_UPD_SIZE */ + case THUNK_0_1: + case THUNK_1_1: + case THUNK_0_2: + case THUNK_2_0: +#ifdef NO_PROMOTE_THUNKS + if (bd->gen->no == 0 && + bd->step->no != 0 && + bd->step->no == bd->gen->n_steps-1) { + step = bd->step; + } +#endif + return copy(q,sizeofW(StgHeader)+2,step); + + case FUN_1_1: + case FUN_0_2: + case FUN_2_0: + case CONSTR_1_1: + case CONSTR_0_2: + case CONSTR_2_0: + return copy(q,sizeofW(StgHeader)+2,step); + case FUN: case THUNK: case CONSTR: @@ -1059,20 +1196,16 @@ loop: case CAF_ENTERED: case WEAK: case FOREIGN: - to = copy(q,sizeW_fromITBL(info),bd); - upd_evacuee(q,to); - return to; + case STABLE_NAME: + return copy(q,sizeW_fromITBL(info),step); case CAF_BLACKHOLE: case BLACKHOLE: - to = copyPart(q,BLACKHOLE_sizeW(),sizeofW(StgHeader),bd); - upd_evacuee(q,to); - return to; + return copyPart(q,BLACKHOLE_sizeW(),sizeofW(StgHeader),step); case BLACKHOLE_BQ: - to = copy(q,BLACKHOLE_sizeW(),bd); - upd_evacuee(q,to); - evacuate_mutable((StgMutClosure *)to); + to = copy(q,BLACKHOLE_sizeW(),step); + recordMutable((StgMutClosure *)to); return to; case THUNK_SELECTOR: @@ -1084,13 +1217,18 @@ loop: selectee_info = get_itbl(selectee); switch (selectee_info->type) { case CONSTR: + case CONSTR_1_0: + case CONSTR_0_1: + case CONSTR_2_0: + case CONSTR_1_1: + case CONSTR_0_2: case CONSTR_STATIC: { - StgNat32 offset = info->layout.selector_offset; + StgWord32 offset = info->layout.selector_offset; /* check that the size is in range */ ASSERT(offset < - (StgNat32)(selectee_info->layout.payload.ptrs + + (StgWord32)(selectee_info->layout.payload.ptrs + selectee_info->layout.payload.nptrs)); /* perform the selection! */ @@ -1100,11 +1238,12 @@ loop: * with the evacuation, just update the source address with * a pointer to the (evacuated) constructor field. */ - if (IS_USER_PTR(q)) { + if (HEAP_ALLOCED(q)) { bdescr *bd = Bdescr((P_)q); if (bd->evacuated) { if (bd->gen->no < evac_gen) { failed_to_evac = rtsTrue; + TICK_GC_FAILED_PROMOTION(); } return q; } @@ -1133,6 +1272,11 @@ loop: goto selector_loop; case THUNK: + case THUNK_1_0: + case THUNK_0_1: + case THUNK_2_0: + case THUNK_1_1: + case THUNK_0_2: case THUNK_STATIC: case THUNK_SELECTOR: /* aargh - do recursively???? */ @@ -1147,9 +1291,7 @@ loop: barf("evacuate: THUNK_SELECTOR: strange selectee"); } } - to = copy(q,THUNK_SELECTOR_sizeW(),bd); - upd_evacuee(q,to); - return to; + return copy(q,THUNK_SELECTOR_sizeW(),step); case IND: case IND_OLDGEN: @@ -1207,9 +1349,7 @@ loop: case PAP: /* these are special - the payload is a copy of a chunk of stack, tagging and all. */ - to = copy(q,pap_sizeW(stgCast(StgPAP*,q)),bd); - upd_evacuee(q,to); - return to; + return copy(q,pap_sizeW(stgCast(StgPAP*,q)),step); case EVACUATED: /* Already evacuated, just return the forwarding address. @@ -1224,11 +1364,11 @@ loop: if (Bdescr((P_)p)->gen->no < evac_gen) { /* fprintf(stderr,"evac failed!\n");*/ failed_to_evac = rtsTrue; - } + TICK_GC_FAILED_PROMOTION(); + } } return ((StgEvacuated*)q)->evacuee; - case MUT_ARR_WORDS: case ARR_WORDS: { nat size = arr_words_sizeW(stgCast(StgArrWords*,q)); @@ -1238,9 +1378,7 @@ loop: return q; } else { /* just copy the block */ - to = copy(q,size,bd); - upd_evacuee(q,to); - return to; + return copy(q,size,step); } } @@ -1254,10 +1392,9 @@ loop: to = q; } else { /* just copy the block */ - to = copy(q,size,bd); - upd_evacuee(q,to); + to = copy(q,size,step); if (info->type == MUT_ARR_PTRS) { - evacuate_mutable((StgMutClosure *)to); + recordMutable((StgMutClosure *)to); } } return to; @@ -1279,7 +1416,7 @@ loop: * list it contains. */ } else { - StgTSO *new_tso = (StgTSO *)copy((StgClosure *)tso,tso_sizeW(tso),bd); + StgTSO *new_tso = (StgTSO *)copy((StgClosure *)tso,tso_sizeW(tso),step); diff = (StgPtr)new_tso - (StgPtr)tso; /* In *words* */ @@ -1289,9 +1426,8 @@ loop: new_tso->splim = (StgPtr)new_tso->splim + diff; relocate_TSO(tso, new_tso); - upd_evacuee(q,(StgClosure *)new_tso); - evacuate_mutable((StgMutClosure *)new_tso); + recordMutable((StgMutClosure *)new_tso); return (StgClosure *)new_tso; } } @@ -1372,7 +1508,24 @@ scavenge_srt(const StgInfoTable *info) srt = stgCast(StgClosure **,info->srt); srt_end = srt + info->srt_len; for (; srt < srt_end; srt++) { - evacuate(*srt); + /* Special-case to handle references to closures hiding out in DLLs, since + double indirections required to get at those. The code generator knows + which is which when generating the SRT, so it stores the (indirect) + reference to the DLL closure in the table by first adding one to it. + We check for this here, and undo the addition before evacuating it. + + If the SRT entry hasn't got bit 0 set, the SRT entry points to a + closure that's fixed at link-time, and no extra magic is required. + */ +#ifdef HAVE_WIN32_DLL_SUPPORT + if ( stgCast(unsigned long,*srt) & 0x1 ) { + evacuate(*stgCast(StgClosure**,(stgCast(unsigned long, *srt) & ~0x1))); + } else { + evacuate(*srt); + } +#else + evacuate(*srt); +#endif } } @@ -1450,6 +1603,54 @@ scavenge(step *step) break; } + case THUNK_2_0: + case FUN_2_0: + scavenge_srt(info); + case CONSTR_2_0: + ((StgClosure *)p)->payload[1] = evacuate(((StgClosure *)p)->payload[1]); + ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]); + p += sizeofW(StgHeader) + 2; + break; + + case THUNK_1_0: + scavenge_srt(info); + ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]); + p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */ + break; + + case FUN_1_0: + scavenge_srt(info); + case CONSTR_1_0: + ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]); + p += sizeofW(StgHeader) + 1; + break; + + case THUNK_0_1: + scavenge_srt(info); + p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */ + break; + + case FUN_0_1: + scavenge_srt(info); + case CONSTR_0_1: + p += sizeofW(StgHeader) + 1; + break; + + case THUNK_0_2: + case FUN_0_2: + scavenge_srt(info); + case CONSTR_0_2: + p += sizeofW(StgHeader) + 2; + break; + + case THUNK_1_1: + case FUN_1_1: + scavenge_srt(info); + case CONSTR_1_1: + ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]); + p += sizeofW(StgHeader) + 2; + break; + case FUN: case THUNK: scavenge_srt(info); @@ -1458,6 +1659,7 @@ scavenge(step *step) case CONSTR: case WEAK: case FOREIGN: + case STABLE_NAME: case IND_PERM: case IND_OLDGEN_PERM: case CAF_UNENTERED: @@ -1495,7 +1697,7 @@ scavenge(step *step) evacuate((StgClosure *)bh->blocking_queue); if (failed_to_evac) { failed_to_evac = rtsFalse; - evacuate_mutable((StgMutClosure *)bh); + recordMutable((StgMutClosure *)bh); } p += BLACKHOLE_sizeW(); break; @@ -1551,7 +1753,6 @@ scavenge(step *step) } case ARR_WORDS: - case MUT_ARR_WORDS: /* nothing to follow */ p += arr_words_sizeW(stgCast(StgArrWords*,p)); break; @@ -1581,7 +1782,7 @@ scavenge(step *step) } if (failed_to_evac) { /* we can do this easier... */ - evacuate_mutable((StgMutClosure *)start); + recordMutable((StgMutClosure *)start); failed_to_evac = rtsFalse; } break; @@ -1633,21 +1834,36 @@ scavenge(step *step) objects can have this property. -------------------------------------------------------------------------- */ static rtsBool -scavenge_one(StgPtr p) +scavenge_one(StgClosure *p) { StgInfoTable *info; rtsBool no_luck; - ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO((StgClosure *)p)) - || IS_HUGS_CONSTR_INFO(GET_INFO((StgClosure *)p)))); + ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p)) + || IS_HUGS_CONSTR_INFO(GET_INFO(p)))); - info = get_itbl((StgClosure *)p); + info = get_itbl(p); switch (info -> type) { case FUN: + case FUN_1_0: /* hardly worth specialising these guys */ + case FUN_0_1: + case FUN_1_1: + case FUN_0_2: + case FUN_2_0: case THUNK: + case THUNK_1_0: + case THUNK_0_1: + case THUNK_1_1: + case THUNK_0_2: + case THUNK_2_0: case CONSTR: + case CONSTR_1_0: + case CONSTR_0_1: + case CONSTR_1_1: + case CONSTR_0_2: + case CONSTR_2_0: case WEAK: case FOREIGN: case IND_PERM: @@ -1655,11 +1871,11 @@ scavenge_one(StgPtr p) case CAF_UNENTERED: case CAF_ENTERED: { - StgPtr end; + StgPtr q, end; - end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs; - for (p = (P_)((StgClosure *)p)->payload; p < end; p++) { - (StgClosure *)*p = evacuate((StgClosure *)*p); + end = (P_)p->payload + info->layout.payload.ptrs; + for (q = (P_)p->payload; q < end; q++) { + (StgClosure *)*q = evacuate((StgClosure *)*q); } break; } @@ -1672,7 +1888,7 @@ scavenge_one(StgPtr p) { StgSelector *s = (StgSelector *)p; s->selectee = evacuate(s->selectee); - break; + break; } case AP_UPD: /* same as PAPs */ @@ -1681,7 +1897,7 @@ scavenge_one(StgPtr p) * evacuate the function pointer too... */ { - StgPAP* pap = stgCast(StgPAP*,p); + StgPAP* pap = (StgPAP *)p; pap->fun = evacuate(pap->fun); scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args); @@ -1714,21 +1930,121 @@ scavenge_one(StgPtr p) remove non-mutable objects from the mutable list at this point. -------------------------------------------------------------------------- */ -static StgMutClosure * -scavenge_mutable_list(StgMutClosure *p, nat gen) +static void +scavenge_mut_once_list(generation *gen) { StgInfoTable *info; - StgMutClosure *start; - StgMutClosure **prev; + StgMutClosure *p, *next, *new_list; - evac_gen = 0; + p = gen->mut_once_list; + new_list = END_MUT_LIST; + next = p->mut_link; + + evac_gen = gen->no; + failed_to_evac = rtsFalse; + + for (; p != END_MUT_LIST; p = next, next = p->mut_link) { + + /* make sure the info pointer is into text space */ + ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p)) + || IS_HUGS_CONSTR_INFO(GET_INFO(p)))); + + info = get_itbl(p); + switch(info->type) { + + case IND_OLDGEN: + case IND_OLDGEN_PERM: + case IND_STATIC: + /* Try to pull the indirectee into this generation, so we can + * remove the indirection from the mutable list. + */ + ((StgIndOldGen *)p)->indirectee = + evacuate(((StgIndOldGen *)p)->indirectee); + +#if 0 + /* Debugging code to print out the size of the thing we just + * promoted + */ + { + StgPtr start = gen->steps[0].scan; + bdescr *start_bd = gen->steps[0].scan_bd; + nat size = 0; + scavenge(&gen->steps[0]); + if (start_bd != gen->steps[0].scan_bd) { + size += (P_)BLOCK_ROUND_UP(start) - start; + start_bd = start_bd->link; + while (start_bd != gen->steps[0].scan_bd) { + size += BLOCK_SIZE_W; + start_bd = start_bd->link; + } + size += gen->steps[0].scan - + (P_)BLOCK_ROUND_DOWN(gen->steps[0].scan); + } else { + size = gen->steps[0].scan - start; + } + fprintf(stderr,"evac IND_OLDGEN: %d bytes\n", size * sizeof(W_)); + } +#endif + + /* failed_to_evac might happen if we've got more than two + * generations, we're collecting only generation 0, the + * indirection resides in generation 2 and the indirectee is + * in generation 1. + */ + if (failed_to_evac) { + failed_to_evac = rtsFalse; + p->mut_link = new_list; + new_list = p; + } else { + /* the mut_link field of an IND_STATIC is overloaded as the + * static link field too (it just so happens that we don't need + * both at the same time), so we need to NULL it out when + * removing this object from the mutable list because the static + * link fields are all assumed to be NULL before doing a major + * collection. + */ + p->mut_link = NULL; + } + continue; + + case MUT_VAR: + /* MUT_CONS is a kind of MUT_VAR, except it that we try to remove + * it from the mutable list if possible by promoting whatever it + * points to. + */ + ASSERT(p->header.info == &MUT_CONS_info); + if (scavenge_one(((StgMutVar *)p)->var) == rtsTrue) { + /* didn't manage to promote everything, so put the + * MUT_CONS back on the list. + */ + p->mut_link = new_list; + new_list = p; + } + continue; + + default: + /* shouldn't have anything else on the mutables list */ + barf("scavenge_mut_once_list: strange object?"); + } + } + + gen->mut_once_list = new_list; +} + + +static void +scavenge_mutable_list(generation *gen) +{ + StgInfoTable *info; + StgMutClosure *p, *next; - prev = &start; - start = p; + p = gen->saved_mut_list; + next = p->mut_link; + evac_gen = 0; failed_to_evac = rtsFalse; - for (; p != END_MUT_LIST; p = *prev) { + for (; p != END_MUT_LIST; p = next, next = p->mut_link) { /* make sure the info pointer is into text space */ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p)) @@ -1745,7 +2061,7 @@ scavenge_mutable_list(StgMutClosure *p, nat gen) StgPtr end, q; end = (P_)p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p); - evac_gen = gen; + evac_gen = gen->no; for (q = (P_)((StgMutArrPtrs *)p)->payload; q < end; q++) { (StgClosure *)*q = evacuate((StgClosure *)*q); } @@ -1753,16 +2069,16 @@ scavenge_mutable_list(StgMutClosure *p, nat gen) if (failed_to_evac) { failed_to_evac = rtsFalse; - prev = &p->mut_link; - } else { - *prev = p->mut_link; - } + p->mut_link = gen->mut_list; + gen->mut_list = p; + } continue; } case MUT_ARR_PTRS: /* follow everything */ - prev = &p->mut_link; + p->mut_link = gen->mut_list; + gen->mut_list = p; { StgPtr end, q; @@ -1778,21 +2094,10 @@ scavenge_mutable_list(StgMutClosure *p, nat gen) * it from the mutable list if possible by promoting whatever it * points to. */ - if (p->header.info == &MUT_CONS_info) { - evac_gen = gen; - if (scavenge_one((P_)((StgMutVar *)p)->var) == rtsTrue) { - /* didn't manage to promote everything, so leave the - * MUT_CONS on the list. - */ - prev = &p->mut_link; - } else { - *prev = p->mut_link; - } - evac_gen = 0; - } else { - ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var); - prev = &p->mut_link; - } + ASSERT(p->header.info != &MUT_CONS_info); + ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var); + p->mut_link = gen->mut_list; + gen->mut_list = p; continue; case MVAR: @@ -1801,7 +2106,8 @@ scavenge_mutable_list(StgMutClosure *p, nat gen) (StgClosure *)mvar->head = evacuate((StgClosure *)mvar->head); (StgClosure *)mvar->tail = evacuate((StgClosure *)mvar->tail); (StgClosure *)mvar->value = evacuate((StgClosure *)mvar->value); - prev = &p->mut_link; + p->mut_link = gen->mut_list; + gen->mut_list = p; continue; } @@ -1824,52 +2130,26 @@ scavenge_mutable_list(StgMutClosure *p, nat gen) * point to some younger objects (because we set evac_gen to 0 * above). */ - prev = &tso->mut_link; + tso->mut_link = gen->mut_list; + gen->mut_list = (StgMutClosure *)tso; continue; } - case IND_OLDGEN: - case IND_OLDGEN_PERM: - case IND_STATIC: - /* Try to pull the indirectee into this generation, so we can - * remove the indirection from the mutable list. - */ - evac_gen = gen; - ((StgIndOldGen *)p)->indirectee = - evacuate(((StgIndOldGen *)p)->indirectee); - evac_gen = 0; - - if (failed_to_evac) { - failed_to_evac = rtsFalse; - prev = &p->mut_link; - } else { - *prev = p->mut_link; - /* the mut_link field of an IND_STATIC is overloaded as the - * static link field too (it just so happens that we don't need - * both at the same time), so we need to NULL it out when - * removing this object from the mutable list because the static - * link fields are all assumed to be NULL before doing a major - * collection. - */ - p->mut_link = NULL; - } - continue; - case BLACKHOLE_BQ: { StgBlockingQueue *bh = (StgBlockingQueue *)p; (StgClosure *)bh->blocking_queue = evacuate((StgClosure *)bh->blocking_queue); - prev = &p->mut_link; - break; + p->mut_link = gen->mut_list; + gen->mut_list = p; + continue; } default: /* shouldn't have anything else on the mutables list */ - barf("scavenge_mutable_object: non-mutable object?"); + barf("scavenge_mut_list: strange object?"); } } - return start; } static void @@ -1914,8 +2194,8 @@ scavenge_static(void) if (failed_to_evac) { failed_to_evac = rtsFalse; scavenged_static_objects = STATIC_LINK(info,p); - ((StgMutClosure *)ind)->mut_link = oldest_gen->mut_list; - oldest_gen->mut_list = (StgMutClosure *)ind; + ((StgMutClosure *)ind)->mut_link = oldest_gen->mut_once_list; + oldest_gen->mut_once_list = (StgMutClosure *)ind; } break; } @@ -1962,7 +2242,7 @@ scavenge_stack(StgPtr p, StgPtr stack_end) { StgPtr q; const StgInfoTable* info; - StgNat32 bitmap; + StgWord32 bitmap; /* * Each time around this loop, we are looking at a chunk of stack @@ -1981,14 +2261,13 @@ scavenge_stack(StgPtr p, StgPtr stack_end) /* Is q a pointer to a closure? */ - if (! LOOKS_LIKE_GHC_INFO(q)) { + if (! LOOKS_LIKE_GHC_INFO(q)) { #ifdef DEBUG - if (LOOKS_LIKE_STATIC(q)) { /* Is it a static closure? */ + if ( 0 && LOOKS_LIKE_STATIC_CLOSURE(q) ) { /* Is it a static closure? */ ASSERT(closure_STATIC(stgCast(StgClosure*,q))); - } - /* otherwise, must be a pointer into the allocation space. - */ + } + /* otherwise, must be a pointer into the allocation space. */ #endif (StgClosure *)*p = evacuate((StgClosure *)q); @@ -2033,25 +2312,33 @@ scavenge_stack(StgPtr p, StgPtr stack_end) continue; } else { bdescr *bd = Bdescr((P_)frame->updatee); + step *step; if (bd->gen->no > N) { if (bd->gen->no < evac_gen) { failed_to_evac = rtsTrue; } continue; } + + /* Don't promote blackholes */ + step = bd->step; + if (!(step->gen->no == 0 && + step->no != 0 && + step->no == step->gen->n_steps-1)) { + step = step->to; + } + switch (type) { case BLACKHOLE: case CAF_BLACKHOLE: to = copyPart(frame->updatee, BLACKHOLE_sizeW(), - sizeofW(StgHeader), bd); - upd_evacuee(frame->updatee,to); + sizeofW(StgHeader), step); frame->updatee = to; continue; case BLACKHOLE_BQ: - to = copy(frame->updatee, BLACKHOLE_sizeW(), bd); - upd_evacuee(frame->updatee,to); + to = copy(frame->updatee, BLACKHOLE_sizeW(), step); frame->updatee = to; - evacuate_mutable((StgMutClosure *)to); + recordMutable((StgMutClosure *)to); continue; default: barf("scavenge_stack: UPDATE_FRAME updatee"); @@ -2158,7 +2445,6 @@ scavenge_large(step *step) /* only certain objects can be "large"... */ case ARR_WORDS: - case MUT_ARR_WORDS: /* nothing to follow */ continue; @@ -2186,7 +2472,7 @@ scavenge_large(step *step) } evac_gen = 0; if (failed_to_evac) { - evacuate_mutable((StgMutClosure *)start); + recordMutable((StgMutClosure *)start); } continue; } @@ -2222,7 +2508,7 @@ scavenge_large(step *step) } static void -zeroStaticObjectList(StgClosure* first_static) +zero_static_object_list(StgClosure* first_static) { StgClosure* p; StgClosure* link; @@ -2244,7 +2530,7 @@ zeroStaticObjectList(StgClosure* first_static) * mutable list. */ static void -zeroMutableList(StgMutClosure *first) +zero_mutable_list( StgMutClosure *first ) { StgMutClosure *next, *c; @@ -2271,7 +2557,7 @@ void RevertCAFs(void) } } -void revertDeadCAFs(void) +void revert_dead_CAFs(void) { StgCAF* caf = enteredCAFs; enteredCAFs = END_CAF_LIST; @@ -2295,7 +2581,7 @@ void revertDeadCAFs(void) break; } default: - barf("revertDeadCAFs: enteredCAFs list corrupted"); + barf("revert_dead_CAFs: enteredCAFs list corrupted"); } caf = next; } @@ -2382,15 +2668,16 @@ threadLazyBlackHole(StgTSO *tso) /* if the thunk is already blackholed, it means we've also * already blackholed the rest of the thunks on this stack, * so we can stop early. + * + * The blackhole made for a CAF is a CAF_BLACKHOLE, so they + * don't interfere with this optimisation. */ + if (bh->header.info == &BLACKHOLE_info) { + return; + } - /* Don't for now: when we enter a CAF, we create a black hole on - * the heap and make the update frame point to it. Thus the - * above optimisation doesn't apply. - */ - if (bh->header.info != &BLACKHOLE_info - && bh->header.info != &BLACKHOLE_BQ_info - && bh->header.info != &CAF_BLACKHOLE_info) { + if (bh->header.info != &BLACKHOLE_BQ_info && + bh->header.info != &CAF_BLACKHOLE_info) { SET_INFO(bh,&BLACKHOLE_info); } @@ -2440,8 +2727,8 @@ threadSqueezeStack(StgTSO *tso) * added to the stack, rather than the way we see them in this * walk. (It makes the next loop less confusing.) * - * Could stop if we find an update frame pointing to a black hole, - * but see comment in threadLazyBlackHole(). + * Stop if we find an update frame pointing to a black hole + * (see comment in threadLazyBlackHole()). */ next_frame = NULL; @@ -2450,6 +2737,10 @@ threadSqueezeStack(StgTSO *tso) frame->link = next_frame; next_frame = frame; frame = prev_frame; + if (get_itbl(frame)->type == UPDATE_FRAME + && frame->updatee->header.info == &BLACKHOLE_info) { + break; + } } /* Now, we're at the bottom. Frame points to the lowest update @@ -2547,10 +2838,8 @@ threadSqueezeStack(StgTSO *tso) */ if (is_update_frame) { StgBlockingQueue *bh = (StgBlockingQueue *)frame->updatee; - if (bh->header.info != &BLACKHOLE_info - && bh->header.info != &BLACKHOLE_BQ_info - && bh->header.info != &CAF_BLACKHOLE_info - ) { + if (bh->header.info != &BLACKHOLE_BQ_info && + bh->header.info != &CAF_BLACKHOLE_info) { SET_INFO(bh,&BLACKHOLE_info); } }