/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.109 2001/07/25 12:18:26 simonmar Exp $
+ * $Id: GC.c,v 1.110 2001/07/26 14:29:26 simonmar Exp $
*
* (c) The GHC Team 1998-1999
*
static void scavenge ( step * );
static void scavenge_mark_stack ( void );
static void scavenge_stack ( StgPtr p, StgPtr stack_end );
-static rtsBool scavenge_one ( StgClosure *p );
+static rtsBool scavenge_one ( StgPtr p );
static void scavenge_large ( step * );
static void scavenge_static ( void );
static void scavenge_mutable_list ( generation *g );
static StgPtr *mark_sp;
static StgPtr *mark_splim;
+// Flag and pointers used for falling back to a linear scan when the
+// mark stack overflows.
+static rtsBool mark_stack_overflowed;
+static bdescr *oldgen_scan_bd;
+static StgPtr oldgen_scan;
+
static inline rtsBool
mark_stack_empty(void)
{
}
static inline void
+reset_mark_stack(void)
+{
+ mark_sp = mark_stack;
+}
+
+static inline void
push_mark_stack(StgPtr p)
{
*mark_sp++ = p;
stp->bitmap = bitmap_bdescr;
bitmap = bitmap_bdescr->start;
- IF_DEBUG(gc, fprintf(stderr, "bitmap_size: %d, bitmap: %p\n",
+ IF_DEBUG(gc, belch("bitmap_size: %d, bitmap: %p",
bitmap_size, bitmap););
// don't forget to fill it with zeros!
loop2:
// scavenge objects in compacted generation
- if (mark_stack_bdescr != NULL && !mark_stack_empty()) {
+ if (mark_stack_overflowed || oldgen_scan_bd != NULL ||
+ (mark_stack_bdescr != NULL && !mark_stack_empty())) {
scavenge_mark_stack();
flag = rtsTrue;
}
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 %ld\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks));
+ IF_DEBUG(gc, belch("@@ Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %ld", 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();
w->link = weak_ptr_list;
weak_ptr_list = w;
flag = rtsTrue;
- IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive at %p -> %p\n", w, w->key));
+ IF_DEBUG(weak, belch("Weak pointer still alive at %p -> %p", w, w->key));
continue;
}
else {
if (!is_marked((P_)q,bd)) {
mark((P_)q,bd);
if (mark_stack_full()) {
- barf("ToDo: mark stack full");
+ mark_stack_overflowed = rtsTrue;
+ reset_mark_stack();
}
push_mark_stack((P_)q);
}
static void
scavenge_mark_stack(void)
{
- StgPtr p;
+ StgPtr p, q;
StgInfoTable *info;
nat saved_evac_gen;
evac_gen = oldest_gen->no;
saved_evac_gen = evac_gen;
+linear_scan:
while (!mark_stack_empty()) {
p = pop_mark_stack();
info = get_itbl((StgClosure *)p);
ASSERT(p && (LOOKS_LIKE_GHC_INFO(info) || IS_HUGS_CONSTR_INFO(info)));
+ q = p;
switch (info->type) {
case MVAR:
p, info_type((StgClosure *)p)));
break;
}
-#endif
+#endif // PAR
default:
barf("scavenge_mark_stack: unimplemented/strange closure type %d @ %p",
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- mkMutCons((StgClosure *)p, &generations[evac_gen]);
+ mkMutCons((StgClosure *)q, &generations[evac_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) {
+ IF_DEBUG(gc, belch("scavenge_mark_stack: starting linear scan"));
+ mark_stack_overflowed = rtsFalse;
+ oldgen_scan_bd = oldest_gen->steps[0].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_NONUPD_SIZE;
+ goto loop;
+ }
+ push_mark_stack(oldgen_scan);
+ // ToDo: bump the linear scan by the actual size of the object
+ oldgen_scan += sizeofW(StgHeader) + MIN_NONUPD_SIZE;
+ goto linear_scan;
+ }
+
+ oldgen_scan_bd = oldgen_scan_bd->link;
+ if (oldgen_scan_bd != NULL) {
+ oldgen_scan = oldgen_scan_bd->start;
+ goto loop;
+ }
+ }
+}
/* -----------------------------------------------------------------------------
Scavenge one object.
-------------------------------------------------------------------------- */
static rtsBool
-scavenge_one(StgClosure *p)
+scavenge_one(StgPtr p)
{
- const StgInfoTable *info;
- rtsBool no_luck;
-
- ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
- || IS_HUGS_CONSTR_INFO(GET_INFO(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:
- case IND_OLDGEN_PERM:
+ const StgInfoTable *info;
+ nat saved_evac_gen = evac_gen;
+ rtsBool no_luck;
+
+ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO((StgClosure *)p))
+ || IS_HUGS_CONSTR_INFO(GET_INFO((StgClosure *)p))));
+
+ info = get_itbl((StgClosure *)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:
+ case IND_OLDGEN_PERM:
{
- StgPtr q, end;
-
- end = (P_)p->payload + info->layout.payload.ptrs;
- for (q = (P_)p->payload; q < end; q++) {
- (StgClosure *)*q = evacuate((StgClosure *)*q);
- }
- break;
+ StgPtr q, end;
+
+ end = (StgPtr)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (q = (StgPtr)((StgClosure *)p)->payload; q < end; q++) {
+ (StgClosure *)*q = evacuate((StgClosure *)*q);
+ }
+ break;
}
-
- case CAF_BLACKHOLE:
- case SE_CAF_BLACKHOLE:
- case SE_BLACKHOLE:
- case BLACKHOLE:
- break;
-
- case THUNK_SELECTOR:
+
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ break;
+
+ case THUNK_SELECTOR:
{
- StgSelector *s = (StgSelector *)p;
- s->selectee = evacuate(s->selectee);
- break;
+ StgSelector *s = (StgSelector *)p;
+ s->selectee = evacuate(s->selectee);
+ break;
}
- case AP_UPD: /* same as PAPs */
- case PAP:
- /* Treat a PAP just like a section of stack, not forgetting to
- * evacuate the function pointer too...
- */
- {
- StgPAP* pap = (StgPAP *)p;
+ case ARR_WORDS:
+ // nothing to follow
+ break;
- pap->fun = evacuate(pap->fun);
- scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
- break;
+ case MUT_ARR_PTRS:
+ {
+ // follow everything
+ StgPtr next;
+
+ evac_gen = 0; // repeatedly mutable
+ recordMutable((StgMutClosure *)p);
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ (StgClosure *)*p = evacuate((StgClosure *)*p);
+ }
+ evac_gen = saved_evac_gen;
+ failed_to_evac = rtsFalse;
+ break;
}
- case IND_OLDGEN:
- /* This might happen if for instance a MUT_CONS was pointing to a
- * THUNK which has since been updated. The IND_OLDGEN will
- * be on the mutable list anyway, so we don't need to do anything
- * here.
- */
- break;
+ case MUT_ARR_PTRS_FROZEN:
+ {
+ // follow everything
+ StgPtr next;
+
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ (StgClosure *)*p = evacuate((StgClosure *)*p);
+ }
+ break;
+ }
- case MUT_ARR_PTRS_FROZEN:
- {
- // follow everything
- StgPtr q, next;
+ case TSO:
+ {
+ StgTSO *tso = (StgTSO *)p;
+
+ evac_gen = 0; // repeatedly mutable
+ scavengeTSO(tso);
+ recordMutable((StgMutClosure *)tso);
+ evac_gen = saved_evac_gen;
+ failed_to_evac = rtsFalse;
+ break;
+ }
+
+ case AP_UPD:
+ case PAP:
+ {
+ StgPAP* pap = (StgPAP *)p;
+ pap->fun = evacuate(pap->fun);
+ scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
+ break;
+ }
- q = (StgPtr)p;
- next = q + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (q = (P_)((StgMutArrPtrs *)p)->payload; q < next; q++) {
- (StgClosure *)*q = evacuate((StgClosure *)*q);
- }
- break;
- }
+ case IND_OLDGEN:
+ // This might happen if for instance a MUT_CONS was pointing to a
+ // THUNK which has since been updated. The IND_OLDGEN will
+ // be on the mutable list anyway, so we don't need to do anything
+ // here.
+ break;
- default:
- barf("scavenge_one: strange object %d", (int)(info->type));
- }
+ default:
+ barf("scavenge_one: strange object %d", (int)(info->type));
+ }
- no_luck = failed_to_evac;
- failed_to_evac = rtsFalse;
- return (no_luck);
+ no_luck = failed_to_evac;
+ failed_to_evac = rtsFalse;
+ return (no_luck);
}
/* -----------------------------------------------------------------------------
} else {
size = gen->steps[0].scan - start;
}
- fprintf(stderr,"evac IND_OLDGEN: %ld bytes\n", size * sizeof(W_));
+ belch("evac IND_OLDGEN: %ld bytes", size * sizeof(W_));
}
#endif
* it from the mutable list if possible by promoting whatever it
* points to.
*/
- if (scavenge_one((StgClosure *)((StgMutVar *)p)->var)) {
+ if (scavenge_one((StgPtr)((StgMutVar *)p)->var)) {
/* didn't manage to promote everything, so put the
* MUT_CONS back on the list.
*/
*/
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- scavenged_static_objects = STATIC_LINK(info,p);
+ scavenged_static_objects = IND_STATIC_LINK(p);
((StgMutClosure *)ind)->mut_link = oldest_gen->mut_once_list;
oldest_gen->mut_once_list = (StgMutClosure *)ind;
}
scavenge_large(step *stp)
{
bdescr *bd;
- StgPtr p, q;
- const StgInfoTable* info;
- nat saved_evac_gen = evac_gen; // used for temporarily changing evac_gen
+ StgPtr p;
bd = stp->new_large_objects;
stp->n_scavenged_large_blocks += bd->blocks;
p = bd->start;
- info = get_itbl((StgClosure *)p);
-
- // only certain objects can be "large"...
- q = p;
- switch (info->type) {
-
- case ARR_WORDS:
- // nothing to follow
- break;
-
- case MUT_ARR_PTRS:
- {
- // follow everything
- StgPtr next;
-
- evac_gen = 0; // repeatedly mutable
- recordMutable((StgMutClosure *)p);
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- (StgClosure *)*p = evacuate((StgClosure *)*p);
- }
- evac_gen = saved_evac_gen;
- failed_to_evac = rtsFalse;
- break;
- }
-
- case MUT_ARR_PTRS_FROZEN:
- {
- // follow everything
- StgPtr next;
-
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- (StgClosure *)*p = evacuate((StgClosure *)*p);
- }
- break;
- }
-
- case TSO:
- {
- StgTSO *tso = (StgTSO *)p;
-
- evac_gen = 0; // repeatedly mutable
- scavengeTSO(tso);
- recordMutable((StgMutClosure *)tso);
- evac_gen = saved_evac_gen;
- failed_to_evac = rtsFalse;
- break;
- }
-
- case AP_UPD:
- case PAP:
- {
- StgPAP* pap = (StgPAP *)p;
- pap->fun = evacuate(pap->fun);
- scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
- break;
- }
-
- default:
- barf("scavenge_large: unknown/strange object %d", (int)(info->type));
- }
-
- if (failed_to_evac) {
- failed_to_evac = rtsFalse;
- mkMutCons((StgClosure *)q, &generations[evac_gen]);
+ if (scavenge_one(p)) {
+ mkMutCons((StgClosure *)p, stp->gen);
}
}
}
ASSERT(info->type == IND_STATIC);
if (STATIC_LINK(info,p) == NULL) {
- IF_DEBUG(gccafs, fprintf(stderr, "CAF gc'd at 0x%04lx\n", (long)p));
+ IF_DEBUG(gccafs, belch("CAF gc'd at 0x%04lx", (long)p));
// black hole it
SET_INFO(p,&stg_BLACKHOLE_info);
p = STATIC_LINK2(info,p);
}
- // fprintf(stderr, "%d CAFs live\n", i);
+ // belch("%d CAFs live", i);
}
#endif
if (bh->header.info != &stg_BLACKHOLE_BQ_info &&
bh->header.info != &stg_CAF_BLACKHOLE_info) {
#if (!defined(LAZY_BLACKHOLING)) && defined(DEBUG)
- fprintf(stderr,"Unexpected lazy BHing required at 0x%04x\n",(int)bh);
+ belch("Unexpected lazy BHing required at 0x%04x",(int)bh);
#endif
SET_INFO(bh,&stg_BLACKHOLE_info);
}
StgClosure *updatee_bypass = frame->updatee;
#if DEBUG
- IF_DEBUG(gc, fprintf(stderr, "@@ squeezing frame at %p\n", frame));
+ IF_DEBUG(gc, belch("@@ squeezing frame at %p", frame));
squeezes++;
#endif
bh->header.info != &stg_BLACKHOLE_BQ_info &&
bh->header.info != &stg_CAF_BLACKHOLE_info) {
#if (!defined(LAZY_BLACKHOLING)) && defined(DEBUG)
- fprintf(stderr,"Unexpected lazy BHing required at 0x%04x\n",(int)bh);
+ belch("Unexpected lazy BHing required at 0x%04x",(int)bh);
#endif
#ifdef DEBUG
/* zero out the slop so that the sanity checker can tell
else
next_frame_bottom = tso->sp - 1;
-#if DEBUG
+#if 0
IF_DEBUG(gc,
- fprintf(stderr, "sliding [%p, %p] by %ld\n", sp, next_frame_bottom,
- displacement))
+ belch("sliding [%p, %p] by %ld", sp, next_frame_bottom,
+ displacement))
#endif
while (sp >= next_frame_bottom) {
tso->sp += displacement;
tso->su = prev_frame;
-#if DEBUG
+#if 0
IF_DEBUG(gc,
- fprintf(stderr, "@@ threadSqueezeStack: squeezed %d update-frames; found %d BHs; found %d update-, %d stop-, %d catch, %d seq-frames\n",
+ belch("@@ threadSqueezeStack: squeezed %d update-frames; found %d BHs; found %d update-, %d stop-, %d catch, %d seq-frames",
squeezes, bhs, upd_frames, stop_frames, catch_frames, seq_frames))
#endif
}
projects / ghc-hetmet.git / commitdiff