/* -----------------------------------------------------------------------------
*
- * (c) The GHC Team 1998-2006
+ * (c) The GHC Team 1998-2008
*
* Generational garbage collector: scavenging functions
*
*
* ---------------------------------------------------------------------------*/
+#include "PosixSource.h"
#include "Rts.h"
-#include "RtsFlags.h"
+
#include "Storage.h"
-#include "MBlock.h"
#include "GC.h"
+#include "GCThread.h"
#include "GCUtils.h"
#include "Compact.h"
+#include "MarkStack.h"
#include "Evac.h"
#include "Scav.h"
#include "Apply.h"
#include "Trace.h"
-#include "LdvProfile.h"
#include "Sanity.h"
+#include "Capability.h"
+#include "LdvProfile.h"
static void scavenge_stack (StgPtr p, StgPtr stack_end);
StgLargeBitmap *large_bitmap,
nat size );
+#if defined(THREADED_RTS) && !defined(PARALLEL_GC)
+# define evacuate(a) evacuate1(a)
+# define scavenge_loop(a) scavenge_loop1(a)
+# define scavenge_block(a) scavenge_block1(a)
+# define scavenge_mutable_list(bd,g) scavenge_mutable_list1(bd,g)
+# define scavenge_capability_mut_lists(cap) scavenge_capability_mut_Lists1(cap)
+#endif
+
+/* -----------------------------------------------------------------------------
+ Scavenge a TSO.
+ -------------------------------------------------------------------------- */
+
+STATIC_INLINE void
+scavenge_TSO_link (StgTSO *tso)
+{
+ // We don't always chase the link field: TSOs on the blackhole
+ // queue are not automatically alive, so the link field is a
+ // "weak" pointer in that case.
+ if (tso->why_blocked != BlockedOnBlackHole) {
+ evacuate((StgClosure **)&tso->_link);
+ }
+}
+
+static void
+scavengeTSO (StgTSO *tso)
+{
+ rtsBool saved_eager;
+
+ if (tso->what_next == ThreadRelocated) {
+ // the only way this can happen is if the old TSO was on the
+ // mutable list. We might have other links to this defunct
+ // TSO, so we must update its link field.
+ evacuate((StgClosure**)&tso->_link);
+ return;
+ }
+
+ debugTrace(DEBUG_gc,"scavenging thread %d",(int)tso->id);
+
+ // update the pointer from the Task.
+ if (tso->bound != NULL) {
+ tso->bound->tso = tso;
+ }
+
+ saved_eager = gct->eager_promotion;
+ gct->eager_promotion = rtsFalse;
+
+ if ( tso->why_blocked == BlockedOnMVar
+ || tso->why_blocked == BlockedOnBlackHole
+ || tso->why_blocked == BlockedOnMsgWakeup
+ || tso->why_blocked == BlockedOnMsgThrowTo
+ ) {
+ evacuate(&tso->block_info.closure);
+ }
+ evacuate((StgClosure **)&tso->blocked_exceptions);
+
+ // scavange current transaction record
+ evacuate((StgClosure **)&tso->trec);
+
+ // scavenge this thread's stack
+ scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
+
+ if (gct->failed_to_evac) {
+ tso->dirty = 1;
+ scavenge_TSO_link(tso);
+ } else {
+ tso->dirty = 0;
+ scavenge_TSO_link(tso);
+ if (gct->failed_to_evac) {
+ tso->flags |= TSO_LINK_DIRTY;
+ } else {
+ tso->flags &= ~TSO_LINK_DIRTY;
+ }
+ }
+
+ gct->eager_promotion = saved_eager;
+}
+
+/* -----------------------------------------------------------------------------
+ Mutable arrays of pointers
+ -------------------------------------------------------------------------- */
+
+static StgPtr scavenge_mut_arr_ptrs (StgMutArrPtrs *a)
+{
+ lnat m;
+ rtsBool any_failed;
+ StgPtr p, q;
+
+ any_failed = rtsFalse;
+ p = (StgPtr)&a->payload[0];
+ for (m = 0; (int)m < (int)mutArrPtrsCards(a->ptrs) - 1; m++)
+ {
+ q = p + (1 << MUT_ARR_PTRS_CARD_BITS);
+ for (; p < q; p++) {
+ evacuate((StgClosure**)p);
+ }
+ if (gct->failed_to_evac) {
+ any_failed = rtsTrue;
+ *mutArrPtrsCard(a,m) = 1;
+ gct->failed_to_evac = rtsFalse;
+ } else {
+ *mutArrPtrsCard(a,m) = 0;
+ }
+ }
+
+ q = (StgPtr)&a->payload[a->ptrs];
+ if (p < q) {
+ for (; p < q; p++) {
+ evacuate((StgClosure**)p);
+ }
+ if (gct->failed_to_evac) {
+ any_failed = rtsTrue;
+ *mutArrPtrsCard(a,m) = 1;
+ gct->failed_to_evac = rtsFalse;
+ } else {
+ *mutArrPtrsCard(a,m) = 0;
+ }
+ }
+
+ gct->failed_to_evac = any_failed;
+ return (StgPtr)a + mut_arr_ptrs_sizeW(a);
+}
+
+// scavenge only the marked areas of a MUT_ARR_PTRS
+static StgPtr scavenge_mut_arr_ptrs_marked (StgMutArrPtrs *a)
+{
+ lnat m;
+ StgPtr p, q;
+ rtsBool any_failed;
+
+ any_failed = rtsFalse;
+ for (m = 0; m < mutArrPtrsCards(a->ptrs); m++)
+ {
+ if (*mutArrPtrsCard(a,m) != 0) {
+ p = (StgPtr)&a->payload[m << MUT_ARR_PTRS_CARD_BITS];
+ q = stg_min(p + (1 << MUT_ARR_PTRS_CARD_BITS),
+ (StgPtr)&a->payload[a->ptrs]);
+ for (; p < q; p++) {
+ evacuate((StgClosure**)p);
+ }
+ if (gct->failed_to_evac) {
+ any_failed = rtsTrue;
+ gct->failed_to_evac = rtsFalse;
+ } else {
+ *mutArrPtrsCard(a,m) = 0;
+ }
+ }
+ }
+
+ gct->failed_to_evac = any_failed;
+ return (StgPtr)a + mut_arr_ptrs_sizeW(a);
+}
+
+/* -----------------------------------------------------------------------------
+ Blocks of function args occur on the stack (at the top) and
+ in PAPs.
+ -------------------------------------------------------------------------- */
+
+STATIC_INLINE StgPtr
+scavenge_arg_block (StgFunInfoTable *fun_info, StgClosure **args)
+{
+ StgPtr p;
+ StgWord bitmap;
+ nat size;
+
+ p = (StgPtr)args;
+ switch (fun_info->f.fun_type) {
+ case ARG_GEN:
+ bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
+ size = BITMAP_SIZE(fun_info->f.b.bitmap);
+ goto small_bitmap;
+ case ARG_GEN_BIG:
+ size = GET_FUN_LARGE_BITMAP(fun_info)->size;
+ scavenge_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
+ p += size;
+ break;
+ default:
+ bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
+ size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
+ small_bitmap:
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ evacuate((StgClosure **)p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+ break;
+ }
+ return p;
+}
+
+STATIC_INLINE GNUC_ATTR_HOT StgPtr
+scavenge_PAP_payload (StgClosure *fun, StgClosure **payload, StgWord size)
+{
+ StgPtr p;
+ StgWord bitmap;
+ StgFunInfoTable *fun_info;
+
+ fun_info = get_fun_itbl(UNTAG_CLOSURE(fun));
+ ASSERT(fun_info->i.type != PAP);
+ p = (StgPtr)payload;
+
+ switch (fun_info->f.fun_type) {
+ case ARG_GEN:
+ bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
+ goto small_bitmap;
+ case ARG_GEN_BIG:
+ scavenge_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
+ p += size;
+ break;
+ case ARG_BCO:
+ scavenge_large_bitmap((StgPtr)payload, BCO_BITMAP(fun), size);
+ p += size;
+ break;
+ default:
+ bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
+ small_bitmap:
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ evacuate((StgClosure **)p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+ break;
+ }
+ return p;
+}
+
+STATIC_INLINE GNUC_ATTR_HOT StgPtr
+scavenge_PAP (StgPAP *pap)
+{
+ evacuate(&pap->fun);
+ return scavenge_PAP_payload (pap->fun, pap->payload, pap->n_args);
+}
+
+STATIC_INLINE StgPtr
+scavenge_AP (StgAP *ap)
+{
+ evacuate(&ap->fun);
+ return scavenge_PAP_payload (ap->fun, ap->payload, ap->n_args);
+}
+
+/* -----------------------------------------------------------------------------
+ Scavenge SRTs
+ -------------------------------------------------------------------------- */
/* Similar to scavenge_large_bitmap(), but we don't write back the
* pointers we get back from evacuate().
* srt field in the info table. That's ok, because we'll
* never dereference it.
*/
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
scavenge_srt (StgClosure **srt, nat srt_bitmap)
{
nat bitmap;
// 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.
if ( (unsigned long)(*srt) & 0x1 ) {
- evacuate(stgCast(StgClosure**,(stgCast(unsigned long, *srt) & ~0x1)));
+ evacuate( (StgClosure**) ((unsigned long) (*srt) & ~0x1));
} else {
evacuate(p);
}
}
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
scavenge_thunk_srt(const StgInfoTable *info)
{
StgThunkInfoTable *thunk_info;
scavenge_srt((StgClosure **)GET_SRT(thunk_info), thunk_info->i.srt_bitmap);
}
-STATIC_INLINE void
+STATIC_INLINE GNUC_ATTR_HOT void
scavenge_fun_srt(const StgInfoTable *info)
{
StgFunInfoTable *fun_info;
}
/* -----------------------------------------------------------------------------
- Scavenge a TSO.
+ Scavenge a block from the given scan pointer up to bd->free.
+
+ evac_gen is set by the caller to be either zero (for a step in a
+ generation < N) or G where G is the generation of the step being
+ scavenged.
+
+ We sometimes temporarily change evac_gen back to zero if we're
+ scavenging a mutable object where eager promotion isn't such a good
+ idea.
-------------------------------------------------------------------------- */
-static void
-scavengeTSO (StgTSO *tso)
+static GNUC_ATTR_HOT void
+scavenge_block (bdescr *bd)
{
- rtsBool saved_eager;
+ StgPtr p, q;
+ StgInfoTable *info;
+ rtsBool saved_eager_promotion;
+ gen_workspace *ws;
- if (tso->what_next == ThreadRelocated) {
- // the only way this can happen is if the old TSO was on the
- // mutable list. We might have other links to this defunct
- // TSO, so we must update its link field.
- evacuate((StgClosure**)&tso->_link);
- return;
+ debugTrace(DEBUG_gc, "scavenging block %p (gen %d) @ %p",
+ bd->start, bd->gen_no, bd->u.scan);
+
+ gct->scan_bd = bd;
+ gct->evac_gen = bd->gen;
+ saved_eager_promotion = gct->eager_promotion;
+ gct->failed_to_evac = rtsFalse;
+
+ ws = &gct->gens[bd->gen->no];
+
+ p = bd->u.scan;
+
+ // we might be evacuating into the very object that we're
+ // scavenging, so we have to check the real bd->free pointer each
+ // time around the loop.
+ while (p < bd->free || (bd == ws->todo_bd && p < ws->todo_free)) {
+
+ ASSERT(bd->link == NULL);
+ ASSERT(LOOKS_LIKE_CLOSURE_PTR(p));
+ info = get_itbl((StgClosure *)p);
+
+ ASSERT(gct->thunk_selector_depth == 0);
+
+ q = p;
+ switch (info->type) {
+
+ case MVAR_CLEAN:
+ case MVAR_DIRTY:
+ {
+ StgMVar *mvar = ((StgMVar *)p);
+ gct->eager_promotion = rtsFalse;
+ evacuate((StgClosure **)&mvar->head);
+ evacuate((StgClosure **)&mvar->tail);
+ evacuate((StgClosure **)&mvar->value);
+ gct->eager_promotion = saved_eager_promotion;
+
+ if (gct->failed_to_evac) {
+ mvar->header.info = &stg_MVAR_DIRTY_info;
+ } else {
+ mvar->header.info = &stg_MVAR_CLEAN_info;
+ }
+ p += sizeofW(StgMVar);
+ break;
}
- saved_eager = gct->eager_promotion;
- gct->eager_promotion = rtsFalse;
+ case FUN_2_0:
+ scavenge_fun_srt(info);
+ evacuate(&((StgClosure *)p)->payload[1]);
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
- if ( tso->why_blocked == BlockedOnMVar
- || tso->why_blocked == BlockedOnBlackHole
- || tso->why_blocked == BlockedOnException
- ) {
- evacuate(&tso->block_info.closure);
+ case THUNK_2_0:
+ scavenge_thunk_srt(info);
+ evacuate(&((StgThunk *)p)->payload[1]);
+ evacuate(&((StgThunk *)p)->payload[0]);
+ p += sizeofW(StgThunk) + 2;
+ break;
+
+ case CONSTR_2_0:
+ evacuate(&((StgClosure *)p)->payload[1]);
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_0:
+ scavenge_thunk_srt(info);
+ evacuate(&((StgThunk *)p)->payload[0]);
+ p += sizeofW(StgThunk) + 1;
+ break;
+
+ case FUN_1_0:
+ scavenge_fun_srt(info);
+ case CONSTR_1_0:
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_1:
+ scavenge_thunk_srt(info);
+ p += sizeofW(StgThunk) + 1;
+ break;
+
+ case FUN_0_1:
+ scavenge_fun_srt(info);
+ case CONSTR_0_1:
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_2:
+ scavenge_thunk_srt(info);
+ p += sizeofW(StgThunk) + 2;
+ break;
+
+ case FUN_0_2:
+ scavenge_fun_srt(info);
+ case CONSTR_0_2:
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_1:
+ scavenge_thunk_srt(info);
+ evacuate(&((StgThunk *)p)->payload[0]);
+ p += sizeofW(StgThunk) + 2;
+ break;
+
+ case FUN_1_1:
+ scavenge_fun_srt(info);
+ case CONSTR_1_1:
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case FUN:
+ scavenge_fun_srt(info);
+ goto gen_obj;
+
+ case THUNK:
+ {
+ StgPtr end;
+
+ scavenge_thunk_srt(info);
+ end = (P_)((StgThunk *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgThunk *)p)->payload; p < end; p++) {
+ evacuate((StgClosure **)p);
+ }
+ p += info->layout.payload.nptrs;
+ break;
}
- evacuate((StgClosure **)&tso->blocked_exceptions);
-
- // We don't always chase the link field: TSOs on the blackhole
- // queue are not automatically alive, so the link field is a
- // "weak" pointer in that case.
- if (tso->why_blocked != BlockedOnBlackHole) {
- evacuate((StgClosure **)&tso->link);
+
+ gen_obj:
+ case CONSTR:
+ case WEAK:
+ case PRIM:
+ {
+ StgPtr end;
+
+ end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ evacuate((StgClosure **)p);
+ }
+ p += info->layout.payload.nptrs;
+ break;
}
- // scavange current transaction record
- evacuate((StgClosure **)&tso->trec);
-
- // scavenge this thread's stack
- scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
+ case BCO: {
+ StgBCO *bco = (StgBCO *)p;
+ evacuate((StgClosure **)&bco->instrs);
+ evacuate((StgClosure **)&bco->literals);
+ evacuate((StgClosure **)&bco->ptrs);
+ p += bco_sizeW(bco);
+ break;
+ }
- if (gct->failed_to_evac) {
- tso->flags |= TSO_DIRTY;
- } else {
- tso->flags &= ~TSO_DIRTY;
+ case IND_PERM:
+ if (bd->gen_no != 0) {
+#ifdef PROFILING
+ // @LDV profiling
+ // No need to call LDV_recordDead_FILL_SLOP_DYNAMIC() because an
+ // IND_OLDGEN_PERM closure is larger than an IND_PERM closure.
+ LDV_recordDead((StgClosure *)p, sizeofW(StgInd));
+#endif
+ //
+ // Todo: maybe use SET_HDR() and remove LDV_RECORD_CREATE()?
+ //
+ SET_INFO(((StgClosure *)p), &stg_IND_OLDGEN_PERM_info);
+
+ // We pretend that p has just been created.
+ LDV_RECORD_CREATE((StgClosure *)p);
+ }
+ // fall through
+ case IND_OLDGEN_PERM:
+ evacuate(&((StgInd *)p)->indirectee);
+ p += sizeofW(StgInd);
+ break;
+
+ case MUT_VAR_CLEAN:
+ case MUT_VAR_DIRTY:
+ gct->eager_promotion = rtsFalse;
+ evacuate(&((StgMutVar *)p)->var);
+ gct->eager_promotion = saved_eager_promotion;
+
+ if (gct->failed_to_evac) {
+ ((StgClosure *)q)->header.info = &stg_MUT_VAR_DIRTY_info;
+ } else {
+ ((StgClosure *)q)->header.info = &stg_MUT_VAR_CLEAN_info;
+ }
+ p += sizeofW(StgMutVar);
+ break;
+
+ case CAF_BLACKHOLE:
+ case BLACKHOLE:
+ p += BLACKHOLE_sizeW();
+ break;
+
+ case THUNK_SELECTOR:
+ {
+ StgSelector *s = (StgSelector *)p;
+ evacuate(&s->selectee);
+ p += THUNK_SELECTOR_sizeW();
+ break;
}
- gct->eager_promotion = saved_eager;
-}
+ // A chunk of stack saved in a heap object
+ case AP_STACK:
+ {
+ StgAP_STACK *ap = (StgAP_STACK *)p;
-/* -----------------------------------------------------------------------------
- Blocks of function args occur on the stack (at the top) and
- in PAPs.
- -------------------------------------------------------------------------- */
+ evacuate(&ap->fun);
+ scavenge_stack((StgPtr)ap->payload, (StgPtr)ap->payload + ap->size);
+ p = (StgPtr)ap->payload + ap->size;
+ break;
+ }
-STATIC_INLINE StgPtr
-scavenge_arg_block (StgFunInfoTable *fun_info, StgClosure **args)
-{
- StgPtr p;
- StgWord bitmap;
- nat size;
+ case PAP:
+ p = scavenge_PAP((StgPAP *)p);
+ break;
- p = (StgPtr)args;
- switch (fun_info->f.fun_type) {
- case ARG_GEN:
- bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
- size = BITMAP_SIZE(fun_info->f.b.bitmap);
- goto small_bitmap;
- case ARG_GEN_BIG:
- size = GET_FUN_LARGE_BITMAP(fun_info)->size;
- scavenge_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
- p += size;
+ case AP:
+ p = scavenge_AP((StgAP *)p);
break;
- default:
- bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
- size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
- small_bitmap:
- while (size > 0) {
- if ((bitmap & 1) == 0) {
- evacuate((StgClosure **)p);
- }
- p++;
- bitmap = bitmap >> 1;
- size--;
+
+ case ARR_WORDS:
+ // nothing to follow
+ p += arr_words_sizeW((StgArrWords *)p);
+ break;
+
+ case MUT_ARR_PTRS_CLEAN:
+ case MUT_ARR_PTRS_DIRTY:
+ {
+ // We don't eagerly promote objects pointed to by a mutable
+ // array, but if we find the array only points to objects in
+ // the same or an older generation, we mark it "clean" and
+ // avoid traversing it during minor GCs.
+ gct->eager_promotion = rtsFalse;
+
+ p = scavenge_mut_arr_ptrs((StgMutArrPtrs*)p);
+
+ if (gct->failed_to_evac) {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+ } else {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+ }
+
+ gct->eager_promotion = saved_eager_promotion;
+ gct->failed_to_evac = rtsTrue; // always put it on the mutable list.
+ break;
+ }
+
+ case MUT_ARR_PTRS_FROZEN:
+ case MUT_ARR_PTRS_FROZEN0:
+ // follow everything
+ {
+ p = scavenge_mut_arr_ptrs((StgMutArrPtrs*)p);
+
+ // If we're going to put this object on the mutable list, then
+ // set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
+ if (gct->failed_to_evac) {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
+ } else {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
}
break;
}
- return p;
-}
-STATIC_INLINE StgPtr
-scavenge_PAP_payload (StgClosure *fun, StgClosure **payload, StgWord size)
-{
- StgPtr p;
- StgWord bitmap;
- StgFunInfoTable *fun_info;
-
- fun_info = get_fun_itbl(UNTAG_CLOSURE(fun));
- ASSERT(fun_info->i.type != PAP);
- p = (StgPtr)payload;
+ case TSO:
+ {
+ StgTSO *tso = (StgTSO *)p;
+ scavengeTSO(tso);
+ p += tso_sizeW(tso);
+ break;
+ }
- switch (fun_info->f.fun_type) {
- case ARG_GEN:
- bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
- goto small_bitmap;
- case ARG_GEN_BIG:
- scavenge_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
- p += size;
+ case MUT_PRIM:
+ {
+ StgPtr end;
+
+ gct->eager_promotion = rtsFalse;
+
+ end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ evacuate((StgClosure **)p);
+ }
+ p += info->layout.payload.nptrs;
+
+ gct->eager_promotion = saved_eager_promotion;
+ gct->failed_to_evac = rtsTrue; // mutable
break;
- case ARG_BCO:
- scavenge_large_bitmap((StgPtr)payload, BCO_BITMAP(fun), size);
- p += size;
+ }
+
+ case TREC_CHUNK:
+ {
+ StgWord i;
+ StgTRecChunk *tc = ((StgTRecChunk *) p);
+ TRecEntry *e = &(tc -> entries[0]);
+ gct->eager_promotion = rtsFalse;
+ evacuate((StgClosure **)&tc->prev_chunk);
+ for (i = 0; i < tc -> next_entry_idx; i ++, e++ ) {
+ evacuate((StgClosure **)&e->tvar);
+ evacuate((StgClosure **)&e->expected_value);
+ evacuate((StgClosure **)&e->new_value);
+ }
+ gct->eager_promotion = saved_eager_promotion;
+ gct->failed_to_evac = rtsTrue; // mutable
+ p += sizeofW(StgTRecChunk);
break;
+ }
+
default:
- bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
- small_bitmap:
- while (size > 0) {
- if ((bitmap & 1) == 0) {
- evacuate((StgClosure **)p);
- }
- p++;
- bitmap = bitmap >> 1;
- size--;
+ barf("scavenge: unimplemented/strange closure type %d @ %p",
+ info->type, p);
+ }
+
+ /*
+ * We need to record the current object on the mutable list if
+ * (a) It is actually mutable, or
+ * (b) It contains pointers to a younger generation.
+ * Case (b) arises if we didn't manage to promote everything that
+ * the current object points to into the current generation.
+ */
+ if (gct->failed_to_evac) {
+ gct->failed_to_evac = rtsFalse;
+ if (bd->gen_no > 0) {
+ recordMutableGen_GC((StgClosure *)q, bd->gen_no);
}
- break;
}
- return p;
-}
+ }
-STATIC_INLINE StgPtr
-scavenge_PAP (StgPAP *pap)
-{
- evacuate(&pap->fun);
- return scavenge_PAP_payload (pap->fun, pap->payload, pap->n_args);
-}
+ if (p > bd->free) {
+ gct->copied += ws->todo_free - bd->free;
+ bd->free = p;
+ }
-STATIC_INLINE StgPtr
-scavenge_AP (StgAP *ap)
-{
- evacuate(&ap->fun);
- return scavenge_PAP_payload (ap->fun, ap->payload, ap->n_args);
-}
+ debugTrace(DEBUG_gc, " scavenged %ld bytes",
+ (unsigned long)((bd->free - bd->u.scan) * sizeof(W_)));
+ // update stats: this is a block that has been scavenged
+ gct->scanned += bd->free - bd->u.scan;
+ bd->u.scan = bd->free;
+
+ if (bd != ws->todo_bd) {
+ // we're not going to evac any more objects into
+ // this block, so push it now.
+ push_scanned_block(bd, ws);
+ }
+
+ gct->scan_bd = NULL;
+}
/* -----------------------------------------------------------------------------
Scavenge everything on the mark stack.
{
StgPtr p, q;
StgInfoTable *info;
- step *saved_evac_step;
+ rtsBool saved_eager_promotion;
- gct->evac_step = &oldest_gen->steps[0];
- saved_evac_step = gct->evac_step;
+ gct->evac_gen = oldest_gen;
+ saved_eager_promotion = gct->eager_promotion;
-linear_scan:
- while (!mark_stack_empty()) {
- p = pop_mark_stack();
+ while ((p = pop_mark_stack())) {
ASSERT(LOOKS_LIKE_CLOSURE_PTR(p));
info = get_itbl((StgClosure *)p);
q = p;
- switch (((volatile StgWord *)info)[1] & 0xffff) {
+ switch (info->type) {
case MVAR_CLEAN:
case MVAR_DIRTY:
{
- rtsBool saved_eager_promotion = gct->eager_promotion;
-
StgMVar *mvar = ((StgMVar *)p);
gct->eager_promotion = rtsFalse;
evacuate((StgClosure **)&mvar->head);
gen_obj:
case CONSTR:
case WEAK:
- case STABLE_NAME:
+ case PRIM:
{
StgPtr end;
case MUT_VAR_CLEAN:
case MUT_VAR_DIRTY: {
- rtsBool saved_eager_promotion = gct->eager_promotion;
-
gct->eager_promotion = rtsFalse;
evacuate(&((StgMutVar *)p)->var);
gct->eager_promotion = saved_eager_promotion;
}
case CAF_BLACKHOLE:
- case SE_CAF_BLACKHOLE:
- case SE_BLACKHOLE:
case BLACKHOLE:
case ARR_WORDS:
break;
case MUT_ARR_PTRS_DIRTY:
// follow everything
{
- StgPtr next;
- rtsBool saved_eager;
-
// We don't eagerly promote objects pointed to by a mutable
// array, but if we find the array only points to objects in
// the same or an older generation, we mark it "clean" and
// avoid traversing it during minor GCs.
- saved_eager = gct->eager_promotion;
gct->eager_promotion = rtsFalse;
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- evacuate((StgClosure **)p);
- }
- gct->eager_promotion = saved_eager;
- if (gct->failed_to_evac) {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
- } else {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
- }
+ scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
+ if (gct->failed_to_evac) {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+ } else {
+ ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+ }
+
+ gct->eager_promotion = saved_eager_promotion;
gct->failed_to_evac = rtsTrue; // mutable anyhow.
break;
}
case MUT_ARR_PTRS_FROZEN0:
// follow everything
{
- StgPtr next, q = p;
+ StgPtr q = p;
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- evacuate((StgClosure **)p);
- }
+ scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
// If we're going to put this object on the mutable list, then
// set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
case TSO:
{
scavengeTSO((StgTSO*)p);
- gct->failed_to_evac = rtsTrue; // always on the mutable list
break;
}
- case TVAR_WATCH_QUEUE:
- {
- StgTVarWatchQueue *wq = ((StgTVarWatchQueue *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&wq->closure);
- evacuate((StgClosure **)&wq->next_queue_entry);
- evacuate((StgClosure **)&wq->prev_queue_entry);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
- case TVAR:
- {
- StgTVar *tvar = ((StgTVar *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&tvar->current_value);
- evacuate((StgClosure **)&tvar->first_watch_queue_entry);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
+ case MUT_PRIM:
+ {
+ StgPtr end;
+
+ gct->eager_promotion = rtsFalse;
+
+ end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ evacuate((StgClosure **)p);
+ }
+
+ gct->eager_promotion = saved_eager_promotion;
+ gct->failed_to_evac = rtsTrue; // mutable
+ break;
+ }
+
case TREC_CHUNK:
{
StgWord i;
StgTRecChunk *tc = ((StgTRecChunk *) p);
TRecEntry *e = &(tc -> entries[0]);
- gct->evac_step = 0;
+ gct->eager_promotion = rtsFalse;
evacuate((StgClosure **)&tc->prev_chunk);
for (i = 0; i < tc -> next_entry_idx; i ++, e++ ) {
evacuate((StgClosure **)&e->tvar);
evacuate((StgClosure **)&e->expected_value);
evacuate((StgClosure **)&e->new_value);
}
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
- case TREC_HEADER:
- {
- StgTRecHeader *trec = ((StgTRecHeader *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&trec->enclosing_trec);
- evacuate((StgClosure **)&trec->current_chunk);
- evacuate((StgClosure **)&trec->invariants_to_check);
- gct->evac_step = saved_evac_step;
+ gct->eager_promotion = saved_eager_promotion;
gct->failed_to_evac = rtsTrue; // mutable
break;
}
- case ATOMIC_INVARIANT:
- {
- StgAtomicInvariant *invariant = ((StgAtomicInvariant *) p);
- gct->evac_step = 0;
- evacuate(&invariant->code);
- evacuate((StgClosure **)&invariant->last_execution);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
- case INVARIANT_CHECK_QUEUE:
- {
- StgInvariantCheckQueue *queue = ((StgInvariantCheckQueue *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&queue->invariant);
- evacuate((StgClosure **)&queue->my_execution);
- evacuate((StgClosure **)&queue->next_queue_entry);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
default:
barf("scavenge_mark_stack: unimplemented/strange closure type %d @ %p",
info->type, p);
if (gct->failed_to_evac) {
gct->failed_to_evac = rtsFalse;
- if (gct->evac_step) {
- recordMutableGen_GC((StgClosure *)q, gct->evac_step->gen);
- }
- }
-
- // mark the next bit to indicate "scavenged"
- mark(q+1, Bdescr(q));
-
- } // while (!mark_stack_empty())
-
- // start a new linear scan if the mark stack overflowed at some point
- if (mark_stack_overflowed && oldgen_scan_bd == NULL) {
- debugTrace(DEBUG_gc, "scavenge_mark_stack: starting linear scan");
- mark_stack_overflowed = rtsFalse;
- oldgen_scan_bd = oldest_gen->steps[0].old_blocks;
- oldgen_scan = oldgen_scan_bd->start;
- }
-
- if (oldgen_scan_bd) {
- // push a new thing on the mark stack
- loop:
- // find a closure that is marked but not scavenged, and start
- // from there.
- while (oldgen_scan < oldgen_scan_bd->free
- && !is_marked(oldgen_scan,oldgen_scan_bd)) {
- oldgen_scan++;
- }
-
- if (oldgen_scan < oldgen_scan_bd->free) {
-
- // already scavenged?
- if (is_marked(oldgen_scan+1,oldgen_scan_bd)) {
- oldgen_scan += sizeofW(StgHeader) + MIN_PAYLOAD_SIZE;
- goto loop;
+ if (gct->evac_gen) {
+ recordMutableGen_GC((StgClosure *)q, gct->evac_gen->no);
}
- push_mark_stack(oldgen_scan);
- // ToDo: bump the linear scan by the actual size of the object
- oldgen_scan += sizeofW(StgHeader) + MIN_PAYLOAD_SIZE;
- goto linear_scan;
- }
-
- oldgen_scan_bd = oldgen_scan_bd->link;
- if (oldgen_scan_bd != NULL) {
- oldgen_scan = oldgen_scan_bd->start;
- goto loop;
}
- }
+ } // while (p = pop_mark_stack())
}
/* -----------------------------------------------------------------------------
scavenge_one(StgPtr p)
{
const StgInfoTable *info;
- step *saved_evac_step = gct->evac_step;
rtsBool no_luck;
+ rtsBool saved_eager_promotion;
+ saved_eager_promotion = gct->eager_promotion;
+
ASSERT(LOOKS_LIKE_CLOSURE_PTR(p));
info = get_itbl((StgClosure *)p);
case MVAR_CLEAN:
case MVAR_DIRTY:
{
- rtsBool saved_eager_promotion = gct->eager_promotion;
-
StgMVar *mvar = ((StgMVar *)p);
gct->eager_promotion = rtsFalse;
evacuate((StgClosure **)&mvar->head);
case CONSTR_0_2:
case CONSTR_2_0:
case WEAK:
+ case PRIM:
case IND_PERM:
{
StgPtr q, end;
case MUT_VAR_CLEAN:
case MUT_VAR_DIRTY: {
StgPtr q = p;
- rtsBool saved_eager_promotion = gct->eager_promotion;
gct->eager_promotion = rtsFalse;
evacuate(&((StgMutVar *)p)->var);
}
case CAF_BLACKHOLE:
- case SE_CAF_BLACKHOLE:
- case SE_BLACKHOLE:
case BLACKHOLE:
break;
case MUT_ARR_PTRS_CLEAN:
case MUT_ARR_PTRS_DIRTY:
{
- StgPtr next, q;
- rtsBool saved_eager;
-
// We don't eagerly promote objects pointed to by a mutable
// array, but if we find the array only points to objects in
// the same or an older generation, we mark it "clean" and
// avoid traversing it during minor GCs.
- saved_eager = gct->eager_promotion;
gct->eager_promotion = rtsFalse;
- q = p;
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- evacuate((StgClosure **)p);
- }
- gct->eager_promotion = saved_eager;
+
+ scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
if (gct->failed_to_evac) {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
} else {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
}
+ gct->eager_promotion = saved_eager_promotion;
gct->failed_to_evac = rtsTrue;
break;
}
case MUT_ARR_PTRS_FROZEN0:
{
// follow everything
- StgPtr next, q=p;
-
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- evacuate((StgClosure **)p);
- }
-
+ scavenge_mut_arr_ptrs((StgMutArrPtrs *)p);
+
// If we're going to put this object on the mutable list, then
// set its info ptr to MUT_ARR_PTRS_FROZEN0 to indicate that.
if (gct->failed_to_evac) {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN0_info;
} else {
- ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_FROZEN_info;
}
break;
}
case TSO:
{
scavengeTSO((StgTSO*)p);
- gct->failed_to_evac = rtsTrue; // always on the mutable list
break;
}
- case TVAR_WATCH_QUEUE:
- {
- StgTVarWatchQueue *wq = ((StgTVarWatchQueue *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&wq->closure);
- evacuate((StgClosure **)&wq->next_queue_entry);
- evacuate((StgClosure **)&wq->prev_queue_entry);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
+ case MUT_PRIM:
+ {
+ StgPtr end;
+
+ gct->eager_promotion = rtsFalse;
+
+ end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ evacuate((StgClosure **)p);
+ }
- case TVAR:
- {
- StgTVar *tvar = ((StgTVar *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&tvar->current_value);
- evacuate((StgClosure **)&tvar->first_watch_queue_entry);
- gct->evac_step = saved_evac_step;
+ gct->eager_promotion = saved_eager_promotion;
gct->failed_to_evac = rtsTrue; // mutable
break;
- }
- case TREC_HEADER:
- {
- StgTRecHeader *trec = ((StgTRecHeader *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&trec->enclosing_trec);
- evacuate((StgClosure **)&trec->current_chunk);
- evacuate((StgClosure **)&trec->invariants_to_check);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
+ }
case TREC_CHUNK:
{
StgWord i;
StgTRecChunk *tc = ((StgTRecChunk *) p);
TRecEntry *e = &(tc -> entries[0]);
- gct->evac_step = 0;
+ gct->eager_promotion = rtsFalse;
evacuate((StgClosure **)&tc->prev_chunk);
for (i = 0; i < tc -> next_entry_idx; i ++, e++ ) {
evacuate((StgClosure **)&e->tvar);
evacuate((StgClosure **)&e->expected_value);
evacuate((StgClosure **)&e->new_value);
}
- gct->evac_step = saved_evac_step;
+ gct->eager_promotion = saved_eager_promotion;
gct->failed_to_evac = rtsTrue; // mutable
break;
}
- case ATOMIC_INVARIANT:
- {
- StgAtomicInvariant *invariant = ((StgAtomicInvariant *) p);
- gct->evac_step = 0;
- evacuate(&invariant->code);
- evacuate((StgClosure **)&invariant->last_execution);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
- case INVARIANT_CHECK_QUEUE:
- {
- StgInvariantCheckQueue *queue = ((StgInvariantCheckQueue *) p);
- gct->evac_step = 0;
- evacuate((StgClosure **)&queue->invariant);
- evacuate((StgClosure **)&queue->my_execution);
- evacuate((StgClosure **)&queue->next_queue_entry);
- gct->evac_step = saved_evac_step;
- gct->failed_to_evac = rtsTrue; // mutable
- break;
- }
-
+ case IND:
+ // IND can happen, for example, when the interpreter allocates
+ // a gigantic AP closure (more than one block), which ends up
+ // on the large-object list and then gets updated. See #3424.
case IND_OLDGEN:
case IND_OLDGEN_PERM:
case IND_STATIC:
- {
- /* Careful here: a THUNK can be on the mutable list because
- * it contains pointers to young gen objects. If such a thunk
- * is updated, the IND_OLDGEN will be added to the mutable
- * list again, and we'll scavenge it twice. evacuate()
- * doesn't check whether the object has already been
- * evacuated, so we perform that check here.
- */
- StgClosure *q = ((StgInd *)p)->indirectee;
- if (HEAP_ALLOCED(q) && Bdescr((StgPtr)q)->flags & BF_EVACUATED) {
- break;
- }
evacuate(&((StgInd *)p)->indirectee);
- }
#if 0 && defined(DEBUG)
if (RtsFlags.DebugFlags.gc)
* promoted
*/
{
- StgPtr start = gen->steps[0].scan;
- bdescr *start_bd = gen->steps[0].scan_bd;
+ StgPtr start = gen->scan;
+ bdescr *start_bd = gen->scan_bd;
nat size = 0;
- scavenge(&gen->steps[0]);
- if (start_bd != gen->steps[0].scan_bd) {
+ scavenge(&gen);
+ if (start_bd != gen->scan_bd) {
size += (P_)BLOCK_ROUND_UP(start) - start;
start_bd = start_bd->link;
- while (start_bd != gen->steps[0].scan_bd) {
+ while (start_bd != gen->scan_bd) {
size += BLOCK_SIZE_W;
start_bd = start_bd->link;
}
- size += gen->steps[0].scan -
- (P_)BLOCK_ROUND_DOWN(gen->steps[0].scan);
+ size += gen->scan -
+ (P_)BLOCK_ROUND_DOWN(gen->scan);
} else {
- size = gen->steps[0].scan - start;
+ size = gen->scan - start;
}
debugBelch("evac IND_OLDGEN: %ld bytes", size * sizeof(W_));
}
-------------------------------------------------------------------------- */
void
-scavenge_mutable_list(generation *gen)
+scavenge_mutable_list(bdescr *bd, generation *gen)
{
- bdescr *bd;
StgPtr p, q;
- bd = gen->saved_mut_list;
-
- gct->evac_step = &gen->steps[0];
+ gct->evac_gen = gen;
for (; bd != NULL; bd = bd->link) {
for (q = bd->start; q < bd->free; q++) {
p = (StgPtr)*q;
// definitely doesn't point into a young generation.
// Clean objects don't need to be scavenged. Some clean
// objects (MUT_VAR_CLEAN) are not kept on the mutable
- // list at all; others, such as MUT_ARR_PTRS_CLEAN and
- // TSO, are always on the mutable list.
+ // list at all; others, such as TSO
+ // are always on the mutable list.
//
switch (get_itbl((StgClosure *)p)->type) {
case MUT_ARR_PTRS_CLEAN:
- recordMutableGen_GC((StgClosure *)p,gen);
+ recordMutableGen_GC((StgClosure *)p,gen->no);
continue;
+ case MUT_ARR_PTRS_DIRTY:
+ {
+ rtsBool saved_eager_promotion;
+ saved_eager_promotion = gct->eager_promotion;
+ gct->eager_promotion = rtsFalse;
+
+ scavenge_mut_arr_ptrs_marked((StgMutArrPtrs *)p);
+
+ if (gct->failed_to_evac) {
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+ } else {
+ ((StgClosure *)p)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+ }
+
+ gct->eager_promotion = saved_eager_promotion;
+ gct->failed_to_evac = rtsFalse;
+ recordMutableGen_GC((StgClosure *)p,gen->no);
+ continue;
+ }
case TSO: {
StgTSO *tso = (StgTSO *)p;
- if ((tso->flags & TSO_DIRTY) == 0) {
- // A clean TSO: we don't have to traverse its
- // stack. However, we *do* follow the link field:
- // we don't want to have to mark a TSO dirty just
- // because we put it on a different queue.
- if (tso->why_blocked != BlockedOnBlackHole) {
- evacuate((StgClosure **)&tso->link);
- }
- recordMutableGen_GC((StgClosure *)p,gen);
+ if (tso->dirty == 0) {
+ // Should be on the mutable list because its link
+ // field is dirty. However, in parallel GC we may
+ // have a thread on multiple mutable lists, so
+ // this assertion would be invalid:
+ // ASSERT(tso->flags & TSO_LINK_DIRTY);
+
+ scavenge_TSO_link(tso);
+ if (gct->failed_to_evac) {
+ recordMutableGen_GC((StgClosure *)p,gen->no);
+ gct->failed_to_evac = rtsFalse;
+ } else {
+ tso->flags &= ~TSO_LINK_DIRTY;
+ }
continue;
}
}
if (scavenge_one(p)) {
// didn't manage to promote everything, so put the
// object back on the list.
- recordMutableGen_GC((StgClosure *)p,gen);
+ recordMutableGen_GC((StgClosure *)p,gen->no);
}
}
}
+}
- // free the old mut_list
- freeChain_sync(gen->saved_mut_list);
- gen->saved_mut_list = NULL;
+void
+scavenge_capability_mut_lists (Capability *cap)
+{
+ nat g;
+
+ /* Mutable lists from each generation > N
+ * we want to *scavenge* these roots, not evacuate them: they're not
+ * going to move in this GC.
+ * Also do them in reverse generation order, for the usual reason:
+ * namely to reduce the likelihood of spurious old->new pointers.
+ */
+ for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
+ scavenge_mutable_list(cap->saved_mut_lists[g], &generations[g]);
+ freeChain_sync(cap->saved_mut_lists[g]);
+ cap->saved_mut_lists[g] = NULL;
+ }
}
/* -----------------------------------------------------------------------------
/* Always evacuate straight to the oldest generation for static
* objects */
- gct->evac_step = &oldest_gen->steps[0];
+ gct->evac_gen = oldest_gen;
/* keep going until we've scavenged all the objects on the linked
list... */
*/
if (gct->failed_to_evac) {
gct->failed_to_evac = rtsFalse;
- recordMutableGen_GC((StgClosure *)p,oldest_gen);
+ recordMutableGen_GC((StgClosure *)p,oldest_gen->no);
}
break;
}
// the indirection into an IND_PERM, so that evacuate will
// copy the indirection into the old generation instead of
// discarding it.
+ //
+ // Note [upd-black-hole]
+ // One slight hiccup is that the THUNK_SELECTOR machinery can
+ // overwrite the updatee with an IND. In parallel GC, this
+ // could even be happening concurrently, so we can't check for
+ // the IND. Fortunately if we assume that blackholing is
+ // happening (either lazy or eager), then we can be sure that
+ // the updatee is never a THUNK_SELECTOR and we're ok.
+ // NB. this is a new invariant: blackholing is not optional.
{
nat type;
- type = get_itbl(((StgUpdateFrame *)p)->updatee)->type;
- if (type == IND) {
- ((StgUpdateFrame *)p)->updatee->header.info =
- (StgInfoTable *)&stg_IND_PERM_info;
- } else if (type == IND_OLDGEN) {
- ((StgUpdateFrame *)p)->updatee->header.info =
- (StgInfoTable *)&stg_IND_OLDGEN_PERM_info;
- }
- evacuate(&((StgUpdateFrame *)p)->updatee);
- p += sizeofW(StgUpdateFrame);
- continue;
+ const StgInfoTable *i;
+ StgClosure *updatee;
+
+ updatee = ((StgUpdateFrame *)p)->updatee;
+ i = updatee->header.info;
+ if (!IS_FORWARDING_PTR(i)) {
+ type = get_itbl(updatee)->type;
+ if (type == IND) {
+ updatee->header.info = &stg_IND_PERM_info;
+ } else if (type == IND_OLDGEN) {
+ updatee->header.info = &stg_IND_OLDGEN_PERM_info;
+ }
+ }
+ evacuate(&((StgUpdateFrame *)p)->updatee);
+ ASSERT(GET_CLOSURE_TAG(((StgUpdateFrame *)p)->updatee) == 0);
+ p += sizeofW(StgUpdateFrame);
+ continue;
}
// small bitmap (< 32 entries, or 64 on a 64-bit machine)
/*-----------------------------------------------------------------------------
scavenge the large object list.
- evac_step set by caller; similar games played with evac_step as with
+ evac_gen set by caller; similar games played with evac_gen as with
scavenge() - see comment at the top of scavenge(). Most large
- objects are (repeatedly) mutable, so most of the time evac_step will
+ objects are (repeatedly) mutable, so most of the time evac_gen will
be zero.
--------------------------------------------------------------------------- */
static void
-scavenge_large (step_workspace *ws)
+scavenge_large (gen_workspace *ws)
{
bdescr *bd;
StgPtr p;
- gct->evac_step = ws->stp;
+ gct->evac_gen = ws->gen;
bd = ws->todo_large_objects;
// the front when evacuating.
ws->todo_large_objects = bd->link;
- ACQUIRE_SPIN_LOCK(&ws->stp->sync_large_objects);
- dbl_link_onto(bd, &ws->stp->scavenged_large_objects);
- ws->stp->n_scavenged_large_blocks += bd->blocks;
- RELEASE_SPIN_LOCK(&ws->stp->sync_large_objects);
+ ACQUIRE_SPIN_LOCK(&ws->gen->sync_large_objects);
+ dbl_link_onto(bd, &ws->gen->scavenged_large_objects);
+ ws->gen->n_scavenged_large_blocks += bd->blocks;
+ RELEASE_SPIN_LOCK(&ws->gen->sync_large_objects);
p = bd->start;
if (scavenge_one(p)) {
- if (ws->stp->gen_no > 0) {
- recordMutableGen_GC((StgClosure *)p, ws->stp->gen);
+ if (ws->gen->no > 0) {
+ recordMutableGen_GC((StgClosure *)p, ws->gen->no);
}
}
+
+ // stats
+ gct->scanned += closure_sizeW((StgClosure*)p);
}
}
/* ----------------------------------------------------------------------------
- Scavenge a block
- ------------------------------------------------------------------------- */
-
-#define PARALLEL_GC
-#include "Scav.c-inc"
-#undef PARALLEL_GC
-#include "Scav.c-inc"
-
-/* ----------------------------------------------------------------------------
Look for work to do.
- We look for the oldest step that has either a todo block that can
+ We look for the oldest gen that has either a todo block that can
be scanned, or a block of work on the global queue that we can
scan.
static rtsBool
scavenge_find_work (void)
{
- int s;
- step_workspace *ws;
+ int g;
+ gen_workspace *ws;
rtsBool did_something, did_anything;
bdescr *bd;
loop:
did_something = rtsFalse;
- for (s = total_steps-1; s >= 0; s--) {
- if (s == 0 && RtsFlags.GcFlags.generations > 1) {
- continue;
- }
- ws = &gct->steps[s];
-
- if (ws->todo_bd != NULL)
- {
- ws->todo_bd->free = ws->todo_free;
- }
-
- // If we have a todo block and no scan block, start
- // scanning the todo block.
- if (ws->scan_bd == NULL && ws->todo_bd != NULL)
- {
- ws->scan_bd = ws->todo_bd;
- ws->scan = ws->scan_bd->start;
- }
+ for (g = RtsFlags.GcFlags.generations-1; g >= 0; g--) {
+ ws = &gct->gens[g];
+ gct->scan_bd = NULL;
+
// If we have a scan block with some work to do,
// scavenge everything up to the free pointer.
- if (ws->scan != NULL && ws->scan < ws->scan_bd->free)
+ if (ws->todo_bd->u.scan < ws->todo_free)
{
- if (n_gc_threads == 1) {
- scavenge_block1(ws->scan_bd, ws->scan);
- } else {
- scavenge_block(ws->scan_bd, ws->scan);
- }
- ws->scan = ws->scan_bd->free;
+ scavenge_block(ws->todo_bd);
did_something = rtsTrue;
- }
-
- if (ws->scan_bd != NULL && ws->scan == ws->scan_bd->free
- && ws->scan_bd != ws->todo_bd)
- {
- // we're not going to evac any more objects into
- // this block, so push it now.
- push_scan_block(ws->scan_bd, ws);
- ws->scan_bd = NULL;
- ws->scan = NULL;
- // we might be able to scan the todo block now.
- did_something = rtsTrue;
+ break;
}
- if (did_something) break;
-
// If we have any large objects to scavenge, do them now.
if (ws->todo_large_objects) {
scavenge_large(ws);
break;
}
- if ((bd = grab_todo_block(ws)) != NULL) {
- // no need to assign this to ws->scan_bd, we're going
- // to scavenge the whole thing and then push it on
- // our scavd list. This saves pushing out the
- // scan_bd block, which might be partial.
- if (n_gc_threads == 1) {
- scavenge_block1(bd, bd->start);
- } else {
- scavenge_block(bd, bd->start);
- }
- push_scan_block(bd, ws);
+ if ((bd = grab_local_todo_block(ws)) != NULL) {
+ scavenge_block(bd);
did_something = rtsTrue;
break;
}
did_anything = rtsTrue;
goto loop;
}
+
+#if defined(THREADED_RTS)
+ if (work_stealing) {
+ // look for work to steal
+ for (g = RtsFlags.GcFlags.generations-1; g >= 0; g--) {
+ if ((bd = steal_todo_block(g)) != NULL) {
+ scavenge_block(bd);
+ did_something = rtsTrue;
+ break;
+ }
+ }
+
+ if (did_something) {
+ did_anything = rtsTrue;
+ goto loop;
+ }
+ }
+#endif
+
// only return when there is no more work to do
return did_anything;
}
// scavenge objects in compacted generation
- if (mark_stack_overflowed || oldgen_scan_bd != NULL ||
- (mark_stack_bdescr != NULL && !mark_stack_empty())) {
+ if (mark_stack_bd != NULL && !mark_stack_empty()) {
scavenge_mark_stack();
work_to_do = rtsTrue;
}
if (work_to_do) goto loop;
}
-rtsBool
-any_work (void)
-{
- int s;
- step_workspace *ws;
-
- gct->any_work++;
-
- write_barrier();
-
- // scavenge objects in compacted generation
- if (mark_stack_overflowed || oldgen_scan_bd != NULL ||
- (mark_stack_bdescr != NULL && !mark_stack_empty())) {
- return rtsTrue;
- }
-
- // Check for global work in any step. We don't need to check for
- // local work, because we have already exited scavenge_loop(),
- // which means there is no local work for this thread.
- for (s = total_steps-1; s >= 0; s--) {
- if (s == 0 && RtsFlags.GcFlags.generations > 1) {
- continue;
- }
- ws = &gct->steps[s];
- if (ws->todo_large_objects) return rtsTrue;
- if (ws->stp->todos) return rtsTrue;
- }
-
- gct->no_work++;
-
- return rtsFalse;
-}
projects / ghc-hetmet.git / blobdiff