#define MAX_THUNK_SELECTOR_DEPTH 16
static void eval_thunk_selector (StgClosure **q, StgSelector * p, rtsBool);
+STATIC_INLINE void evacuate_large(StgPtr p);
+
+/* -----------------------------------------------------------------------------
+ Allocate some space in which to copy an object.
+ -------------------------------------------------------------------------- */
STATIC_INLINE StgPtr
alloc_for_copy (nat size, step *stp)
}
/* -----------------------------------------------------------------------------
+ The evacuate() code
+ -------------------------------------------------------------------------- */
+
+#define MINOR_GC
+#include "Evac.c-inc"
+
+#undef MINOR_GC
+#include "Evac.c-inc"
+
+/* -----------------------------------------------------------------------------
Evacuate a large object
This just consists of removing the object from the (doubly-linked)
that has been evacuated, or unset otherwise.
-------------------------------------------------------------------------- */
-
STATIC_INLINE void
evacuate_large(StgPtr p)
{
}
/* -----------------------------------------------------------------------------
- Evacuate
-
- This is called (eventually) for every live object in the system.
-
- The caller to evacuate specifies a desired generation in the
- gct->evac_step thread-local variable. The following conditions apply to
- evacuating an object which resides in generation M when we're
- collecting up to generation N
-
- if M >= gct->evac_step
- if M > N do nothing
- else evac to step->to
-
- if M < gct->evac_step evac to gct->evac_step, step 0
-
- if the object is already evacuated, then we check which generation
- it now resides in.
-
- if M >= gct->evac_step do nothing
- if M < gct->evac_step set gct->failed_to_evac flag to indicate that we
- didn't manage to evacuate this object into gct->evac_step.
-
-
- OPTIMISATION NOTES:
+ Evaluate a THUNK_SELECTOR if possible.
- evacuate() is the single most important function performance-wise
- in the GC. Various things have been tried to speed it up, but as
- far as I can tell the code generated by gcc 3.2 with -O2 is about
- as good as it's going to get. We pass the argument to evacuate()
- in a register using the 'regparm' attribute (see the prototype for
- evacuate() near the top of this file).
+ p points to a THUNK_SELECTOR that we want to evaluate. The
+ result of "evaluating" it will be evacuated and a pointer to the
+ to-space closure will be returned.
- Changing evacuate() to take an (StgClosure **) rather than
- returning the new pointer seems attractive, because we can avoid
- writing back the pointer when it hasn't changed (eg. for a static
- object, or an object in a generation > N). However, I tried it and
- it doesn't help. One reason is that the (StgClosure **) pointer
- gets spilled to the stack inside evacuate(), resulting in far more
- extra reads/writes than we save.
+ If the THUNK_SELECTOR could not be evaluated (its selectee is still
+ a THUNK, for example), then the THUNK_SELECTOR itself will be
+ evacuated.
-------------------------------------------------------------------------- */
-
-REGPARM1 void
-evacuate(StgClosure **p)
-{
- bdescr *bd = NULL;
- step *stp;
- StgClosure *q;
- const StgInfoTable *info;
- StgWord tag;
-
- q = *p;
-
-loop:
- /* The tag and the pointer are split, to be merged after evacing */
- tag = GET_CLOSURE_TAG(q);
- q = UNTAG_CLOSURE(q);
-
- ASSERT(LOOKS_LIKE_CLOSURE_PTR(q));
-
- if (!HEAP_ALLOCED(q)) {
-
- if (!major_gc) return;
-
- info = get_itbl(q);
- switch (info->type) {
-
- case THUNK_STATIC:
- if (info->srt_bitmap != 0 &&
- *THUNK_STATIC_LINK((StgClosure *)q) == NULL) {
- ACQUIRE_SPIN_LOCK(&static_objects_sync);
- if (*THUNK_STATIC_LINK((StgClosure *)q) == NULL) {
- *THUNK_STATIC_LINK((StgClosure *)q) = static_objects;
- static_objects = (StgClosure *)q;
- }
- RELEASE_SPIN_LOCK(&static_objects_sync);
- }
- return;
-
- case FUN_STATIC:
- if (info->srt_bitmap != 0 &&
- *FUN_STATIC_LINK((StgClosure *)q) == NULL) {
- ACQUIRE_SPIN_LOCK(&static_objects_sync);
- if (*FUN_STATIC_LINK((StgClosure *)q) == NULL) {
- *FUN_STATIC_LINK((StgClosure *)q) = static_objects;
- static_objects = (StgClosure *)q;
- }
- RELEASE_SPIN_LOCK(&static_objects_sync);
- }
- return;
-
- case IND_STATIC:
- /* If q->saved_info != NULL, then it's a revertible CAF - it'll be
- * on the CAF list, so don't do anything with it here (we'll
- * scavenge it later).
- */
- if (((StgIndStatic *)q)->saved_info == NULL) {
- ACQUIRE_SPIN_LOCK(&static_objects_sync);
- if (*IND_STATIC_LINK((StgClosure *)q) == NULL) {
- *IND_STATIC_LINK((StgClosure *)q) = static_objects;
- static_objects = (StgClosure *)q;
- }
- RELEASE_SPIN_LOCK(&static_objects_sync);
- }
- return;
-
- case CONSTR_STATIC:
- if (*STATIC_LINK(info,(StgClosure *)q) == NULL) {
- ACQUIRE_SPIN_LOCK(&static_objects_sync);
- // re-test, after acquiring lock
- if (*STATIC_LINK(info,(StgClosure *)q) == NULL) {
- *STATIC_LINK(info,(StgClosure *)q) = static_objects;
- static_objects = (StgClosure *)q;
- }
- RELEASE_SPIN_LOCK(&static_objects_sync);
- /* I am assuming that static_objects pointers are not
- * written to other objects, and thus, no need to retag. */
- }
- return;
-
- case CONSTR_NOCAF_STATIC:
- /* no need to put these on the static linked list, they don't need
- * to be scavenged.
- */
- return;
-
- default:
- barf("evacuate(static): strange closure type %d", (int)(info->type));
- }
- }
-
- bd = Bdescr((P_)q);
-
- if (bd->gen_no > N) {
- /* Can't evacuate this object, because it's in a generation
- * older than the ones we're collecting. Let's hope that it's
- * in gct->evac_step or older, or we will have to arrange to track
- * this pointer using the mutable list.
- */
- if (bd->step < gct->evac_step) {
- // nope
- gct->failed_to_evac = rtsTrue;
- TICK_GC_FAILED_PROMOTION();
- }
- return;
- }
-
- if ((bd->flags & (BF_LARGE | BF_COMPACTED | BF_EVACUATED)) != 0) {
-
- /* pointer into to-space: just return it. This normally
- * shouldn't happen, but alllowing it makes certain things
- * slightly easier (eg. the mutable list can contain the same
- * object twice, for example).
- */
- if (bd->flags & BF_EVACUATED) {
- if (bd->step < gct->evac_step) {
- gct->failed_to_evac = rtsTrue;
- TICK_GC_FAILED_PROMOTION();
- }
- return;
- }
-
- /* evacuate large objects by re-linking them onto a different list.
- */
- if (bd->flags & BF_LARGE) {
- info = get_itbl(q);
- if (info->type == TSO &&
- ((StgTSO *)q)->what_next == ThreadRelocated) {
- q = (StgClosure *)((StgTSO *)q)->link;
- *p = q;
- goto loop;
- }
- evacuate_large((P_)q);
- return;
- }
-
- /* If the object is in a step that we're compacting, then we
- * need to use an alternative evacuate procedure.
- */
- if (bd->flags & BF_COMPACTED) {
- if (!is_marked((P_)q,bd)) {
- mark((P_)q,bd);
- if (mark_stack_full()) {
- mark_stack_overflowed = rtsTrue;
- reset_mark_stack();
- }
- push_mark_stack((P_)q);
- }
- return;
- }
- }
-
- stp = bd->step->to;
-
- info = get_itbl(q);
-
- switch (info->type) {
-
- case WHITEHOLE:
- goto loop;
-
- case MUT_VAR_CLEAN:
- case MUT_VAR_DIRTY:
- case MVAR_CLEAN:
- case MVAR_DIRTY:
- copy(p,q,sizeW_fromITBL(info),stp);
- return;
-
- case CONSTR_0_1:
- {
- StgWord w = (StgWord)q->payload[0];
- if (q->header.info == Czh_con_info &&
- // unsigned, so always true: (StgChar)w >= MIN_CHARLIKE &&
- (StgChar)w <= MAX_CHARLIKE) {
- *p = TAG_CLOSURE(tag,
- (StgClosure *)CHARLIKE_CLOSURE((StgChar)w)
- );
- }
- if (q->header.info == Izh_con_info &&
- (StgInt)w >= MIN_INTLIKE && (StgInt)w <= MAX_INTLIKE) {
- *p = TAG_CLOSURE(tag,
- (StgClosure *)INTLIKE_CLOSURE((StgInt)w)
- );
- }
- else {
- copy_tag(p,q,sizeofW(StgHeader)+1,stp,tag);
- }
- return;
- }
-
- case FUN_0_1:
- case FUN_1_0:
- case CONSTR_1_0:
- copy_tag(p,q,sizeofW(StgHeader)+1,stp,tag);
- return;
-
- case THUNK_1_0:
- case THUNK_0_1:
- copy(p,q,sizeofW(StgThunk)+1,stp);
- return;
-
- case THUNK_1_1:
- case THUNK_2_0:
- case THUNK_0_2:
-#ifdef NO_PROMOTE_THUNKS
- if (bd->gen_no == 0 &&
- bd->step->no != 0 &&
- bd->step->no == generations[bd->gen_no].n_steps-1) {
- stp = bd->step;
- }
-#endif
- copy(p,q,sizeofW(StgThunk)+2,stp);
- return;
-
- case FUN_1_1:
- case FUN_2_0:
- case FUN_0_2:
- case CONSTR_1_1:
- case CONSTR_2_0:
- copy_tag(p,q,sizeofW(StgHeader)+2,stp,tag);
- return;
-
- case CONSTR_0_2:
- copy_tag(p,q,sizeofW(StgHeader)+2,stp,tag);
- return;
-
- case THUNK:
- copy(p,q,thunk_sizeW_fromITBL(info),stp);
- return;
-
- case FUN:
- case IND_PERM:
- case IND_OLDGEN_PERM:
- case WEAK:
- case STABLE_NAME:
- case CONSTR:
- copy_tag(p,q,sizeW_fromITBL(info),stp,tag);
- return;
-
- case BCO:
- copy(p,q,bco_sizeW((StgBCO *)q),stp);
- return;
-
- case CAF_BLACKHOLE:
- case SE_CAF_BLACKHOLE:
- case SE_BLACKHOLE:
- case BLACKHOLE:
- copyPart(p,q,BLACKHOLE_sizeW(),sizeofW(StgHeader),stp);
- return;
-
- case THUNK_SELECTOR:
- eval_thunk_selector(p, (StgSelector *)q, rtsTrue);
- return;
-
- case IND:
- case IND_OLDGEN:
- // follow chains of indirections, don't evacuate them
- q = ((StgInd*)q)->indirectee;
- *p = q;
- goto loop;
-
- case RET_BCO:
- case RET_SMALL:
- case RET_BIG:
- case RET_DYN:
- case UPDATE_FRAME:
- case STOP_FRAME:
- case CATCH_FRAME:
- case CATCH_STM_FRAME:
- case CATCH_RETRY_FRAME:
- case ATOMICALLY_FRAME:
- // shouldn't see these
- barf("evacuate: stack frame at %p\n", q);
-
- case PAP:
- copy(p,q,pap_sizeW((StgPAP*)q),stp);
- return;
-
- case AP:
- copy(p,q,ap_sizeW((StgAP*)q),stp);
- return;
-
- case AP_STACK:
- copy(p,q,ap_stack_sizeW((StgAP_STACK*)q),stp);
- return;
-
- case EVACUATED:
- /* Already evacuated, just return the forwarding address.
- * HOWEVER: if the requested destination generation (gct->evac_step) is
- * older than the actual generation (because the object was
- * already evacuated to a younger generation) then we have to
- * set the gct->failed_to_evac flag to indicate that we couldn't
- * manage to promote the object to the desired generation.
- */
- /*
- * Optimisation: the check is fairly expensive, but we can often
- * shortcut it if either the required generation is 0, or the
- * current object (the EVACUATED) is in a high enough generation.
- * We know that an EVACUATED always points to an object in the
- * same or an older generation. stp is the lowest step that the
- * current object would be evacuated to, so we only do the full
- * check if stp is too low.
- */
- {
- StgClosure *e = ((StgEvacuated*)q)->evacuee;
- *p = e;
- if (stp < gct->evac_step) { // optimisation
- if (HEAP_ALLOCED(e) && Bdescr((P_)e)->step < gct->evac_step) {
- gct->failed_to_evac = rtsTrue;
- TICK_GC_FAILED_PROMOTION();
- }
- }
- return;
- }
-
- case ARR_WORDS:
- // just copy the block
- copy(p,q,arr_words_sizeW((StgArrWords *)q),stp);
- return;
-
- case MUT_ARR_PTRS_CLEAN:
- case MUT_ARR_PTRS_DIRTY:
- case MUT_ARR_PTRS_FROZEN:
- case MUT_ARR_PTRS_FROZEN0:
- // just copy the block
- copy(p,q,mut_arr_ptrs_sizeW((StgMutArrPtrs *)q),stp);
- return;
-
- case TSO:
- {
- StgTSO *tso = (StgTSO *)q;
-
- /* Deal with redirected TSOs (a TSO that's had its stack enlarged).
- */
- if (tso->what_next == ThreadRelocated) {
- q = (StgClosure *)tso->link;
- *p = q;
- goto loop;
- }
-
- /* To evacuate a small TSO, we need to relocate the update frame
- * list it contains.
- */
- {
- StgTSO *new_tso;
- StgPtr r, s;
-
- copyPart(p,(StgClosure *)tso, tso_sizeW(tso), sizeofW(StgTSO), stp);
- new_tso = (StgTSO *)*p;
- move_TSO(tso, new_tso);
- for (r = tso->sp, s = new_tso->sp;
- r < tso->stack+tso->stack_size;) {
- *s++ = *r++;
- }
- return;
- }
- }
-
- case TREC_HEADER:
- copy(p,q,sizeofW(StgTRecHeader),stp);
- return;
-
- case TVAR_WATCH_QUEUE:
- copy(p,q,sizeofW(StgTVarWatchQueue),stp);
- return;
-
- case TVAR:
- copy(p,q,sizeofW(StgTVar),stp);
- return;
-
- case TREC_CHUNK:
- copy(p,q,sizeofW(StgTRecChunk),stp);
- return;
-
- case ATOMIC_INVARIANT:
- copy(p,q,sizeofW(StgAtomicInvariant),stp);
- return;
-
- case INVARIANT_CHECK_QUEUE:
- copy(p,q,sizeofW(StgInvariantCheckQueue),stp);
- return;
-
- default:
- barf("evacuate: strange closure type %d", (int)(info->type));
- }
-
- barf("evacuate");
-}
-
static void
unchain_thunk_selectors(StgSelector *p, StgClosure *val)
{
}
}
-/* -----------------------------------------------------------------------------
- Evaluate a THUNK_SELECTOR if possible.
-
- p points to a THUNK_SELECTOR that we want to evaluate. The
- result of "evaluating" it will be evacuated and a pointer to the
- to-space closure will be returned.
-
- If the THUNK_SELECTOR could not be evaluated (its selectee is still
- a THUNK, for example), then the THUNK_SELECTOR itself will be
- evacuated.
- -------------------------------------------------------------------------- */
-
static void
eval_thunk_selector (StgClosure **q, StgSelector * p, rtsBool evac)
// NB. for legacy reasons, p & q are swapped around :(
--- /dev/null
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team 1998-2006
+ *
+ * Generational garbage collector: evacuation functions
+ *
+ * ---------------------------------------------------------------------------*/
+
+// We have two versions of evacuate(): one for minor GC, and one for
+// non-minor, parallel, GC. This file contains the code for both,
+// controllled by the CPP symbol MINOR_GC.
+
+#ifdef MINOR_GC
+#define copy(a,b,c,d) copy0(a,b,c,d)
+#define copy_tag(a,b,c,d,e) copy_tag0(a,b,c,d,e)
+#define copyPart(a,b,c,d,e) copyPart0(a,b,c,d,e)
+#define evacuate(a) evacuate0(a)
+#else
+#undef copy
+#undef copy_tag
+#undef copyPart
+#undef evacuate
+#endif
+
+STATIC_INLINE void
+copy_tag(StgClosure **p, StgClosure *src, nat size, step *stp)
+{
+ StgPtr to, tagged_to, from;
+ nat i;
+ StgWord info;
+
+#if !defined(MINOR_GC) && defined(THREADED_RTS)
+ do {
+ info = xchg((StgPtr)&src->header.info, (W_)&stg_WHITEHOLE_info);
+ // so.. what is it?
+ } while (info == (W_)&stg_WHITEHOLE_info);
+ if (info == (W_)&stg_EVACUATED_info) {
+ src->header.info = (const StgInfoTable *)info;
+ return evacuate(p); // does the failed_to_evac stuff
+ }
+#else
+ info = (W_)src->header.info;
+ src->header.info = &stg_EVACUATED_info;
+#endif
+
+ to = alloc_for_copy(size,stp);
+ tagged_to = (StgPtr)TAG_CLOSURE(tag,(StgClosure*)to);
+ *p = (StgClosure *)tagged_to;
+
+ TICK_GC_WORDS_COPIED(size);
+
+ from = (StgPtr)src;
+ to[0] = info;
+ for (i = 1; i < size; i++) { // unroll for small i
+ to[i] = from[i];
+ }
+
+// if (to+size+2 < bd->start + BLOCK_SIZE_W) {
+// __builtin_prefetch(to + size + 2, 1);
+// }
+
+ ((StgEvacuated*)from)->evacuee = (StgClosure *)tagged_to;
+#if !defined(MINOR_GC) && defined(THREADED_RTS)
+ write_barrier();
+ ((StgEvacuated*)from)->header.info = &stg_EVACUATED_info;
+#endif
+
+#ifdef PROFILING
+ // We store the size of the just evacuated object in the LDV word so that
+ // the profiler can guess the position of the next object later.
+ SET_EVACUAEE_FOR_LDV(from, size);
+#endif
+}
+
+
+/* Special version of copy() for when we only want to copy the info
+ * pointer of an object, but reserve some padding after it. This is
+ * used to optimise evacuation of BLACKHOLEs.
+ */
+static void
+copyPart(StgClosure **p, StgClosure *src, nat size_to_reserve, nat size_to_copy, step *stp)
+{
+ StgPtr to, from;
+ nat i;
+ StgWord info;
+
+#if !defined(MINOR_GC) && defined(THREADED_RTS)
+ do {
+ info = xchg((StgPtr)&src->header.info, (W_)&stg_WHITEHOLE_info);
+ } while (info == (W_)&stg_WHITEHOLE_info);
+ if (info == (W_)&stg_EVACUATED_info) {
+ src->header.info = (const StgInfoTable *)info;
+ return evacuate(p); // does the failed_to_evac stuff
+ }
+#else
+ info = (W_)src->header.info;
+ src->header.info = &stg_EVACUATED_info;
+#endif
+
+ to = alloc_for_copy(size_to_reserve, stp);
+ *p = (StgClosure *)to;
+
+ TICK_GC_WORDS_COPIED(size_to_copy);
+
+ from = (StgPtr)src;
+ to[0] = info;
+ for (i = 1; i < size_to_copy; i++) { // unroll for small i
+ to[i] = from[i];
+ }
+
+ ((StgEvacuated*)from)->evacuee = (StgClosure *)to;
+#if !defined(MINOR_GC) && defined(THREADED_RTS)
+ write_barrier();
+ ((StgEvacuated*)from)->header.info = &stg_EVACUATED_info;
+#endif
+
+#ifdef PROFILING
+ // We store the size of the just evacuated object in the LDV word so that
+ // the profiler can guess the position of the next object later.
+ SET_EVACUAEE_FOR_LDV(from, size_to_reserve);
+ // fill the slop
+ if (size_to_reserve - size_to_copy > 0)
+ LDV_FILL_SLOP(to + size_to_copy - 1, (int)(size_to_reserve - size_to_copy));
+#endif
+}
+
+
+/* Copy wrappers that don't tag the closure after copying */
+STATIC_INLINE void
+copy(StgClosure **p, StgClosure *src, nat size, step *stp)
+{
+ copy_tag(p,src,size,stp,0);
+}
+
+/* ----------------------------------------------------------------------------
+ Evacuate
+
+ This is called (eventually) for every live object in the system.
+
+ The caller to evacuate specifies a desired generation in the
+ gct->evac_step thread-local variable. The following conditions apply to
+ evacuating an object which resides in generation M when we're
+ collecting up to generation N
+
+ if M >= gct->evac_step
+ if M > N do nothing
+ else evac to step->to
+
+ if M < gct->evac_step evac to gct->evac_step, step 0
+
+ if the object is already evacuated, then we check which generation
+ it now resides in.
+
+ if M >= gct->evac_step do nothing
+ if M < gct->evac_step set gct->failed_to_evac flag to indicate that we
+ didn't manage to evacuate this object into gct->evac_step.
+
+
+ OPTIMISATION NOTES:
+
+ evacuate() is the single most important function performance-wise
+ in the GC. Various things have been tried to speed it up, but as
+ far as I can tell the code generated by gcc 3.2 with -O2 is about
+ as good as it's going to get. We pass the argument to evacuate()
+ in a register using the 'regparm' attribute (see the prototype for
+ evacuate() near the top of this file).
+
+ Changing evacuate() to take an (StgClosure **) rather than
+ returning the new pointer seems attractive, because we can avoid
+ writing back the pointer when it hasn't changed (eg. for a static
+ object, or an object in a generation > N). However, I tried it and
+ it doesn't help. One reason is that the (StgClosure **) pointer
+ gets spilled to the stack inside evacuate(), resulting in far more
+ extra reads/writes than we save.
+ ------------------------------------------------------------------------- */
+
+REGPARM1 void
+evacuate(StgClosure **p)
+{
+ bdescr *bd = NULL;
+ step *stp;
+ StgClosure *q;
+ const StgInfoTable *info;
+ StgWord tag;
+
+ q = *p;
+
+loop:
+ /* The tag and the pointer are split, to be merged after evacing */
+ tag = GET_CLOSURE_TAG(q);
+ q = UNTAG_CLOSURE(q);
+
+ ASSERT(LOOKS_LIKE_CLOSURE_PTR(q));
+
+ if (!HEAP_ALLOCED(q)) {
+
+#ifdef MINOR_GC
+ return;
+#endif
+ if (!major_gc) return;
+
+ info = get_itbl(q);
+ switch (info->type) {
+
+ case THUNK_STATIC:
+ if (info->srt_bitmap != 0 &&
+ *THUNK_STATIC_LINK((StgClosure *)q) == NULL) {
+ ACQUIRE_SPIN_LOCK(&static_objects_sync);
+ if (*THUNK_STATIC_LINK((StgClosure *)q) == NULL) {
+ *THUNK_STATIC_LINK((StgClosure *)q) = static_objects;
+ static_objects = (StgClosure *)q;
+ }
+ RELEASE_SPIN_LOCK(&static_objects_sync);
+ }
+ return;
+
+ case FUN_STATIC:
+ if (info->srt_bitmap != 0 &&
+ *FUN_STATIC_LINK((StgClosure *)q) == NULL) {
+ ACQUIRE_SPIN_LOCK(&static_objects_sync);
+ if (*FUN_STATIC_LINK((StgClosure *)q) == NULL) {
+ *FUN_STATIC_LINK((StgClosure *)q) = static_objects;
+ static_objects = (StgClosure *)q;
+ }
+ RELEASE_SPIN_LOCK(&static_objects_sync);
+ }
+ return;
+
+ case IND_STATIC:
+ /* If q->saved_info != NULL, then it's a revertible CAF - it'll be
+ * on the CAF list, so don't do anything with it here (we'll
+ * scavenge it later).
+ */
+ if (((StgIndStatic *)q)->saved_info == NULL) {
+ ACQUIRE_SPIN_LOCK(&static_objects_sync);
+ if (*IND_STATIC_LINK((StgClosure *)q) == NULL) {
+ *IND_STATIC_LINK((StgClosure *)q) = static_objects;
+ static_objects = (StgClosure *)q;
+ }
+ RELEASE_SPIN_LOCK(&static_objects_sync);
+ }
+ return;
+
+ case CONSTR_STATIC:
+ if (*STATIC_LINK(info,(StgClosure *)q) == NULL) {
+ ACQUIRE_SPIN_LOCK(&static_objects_sync);
+ // re-test, after acquiring lock
+ if (*STATIC_LINK(info,(StgClosure *)q) == NULL) {
+ *STATIC_LINK(info,(StgClosure *)q) = static_objects;
+ static_objects = (StgClosure *)q;
+ }
+ RELEASE_SPIN_LOCK(&static_objects_sync);
+ /* I am assuming that static_objects pointers are not
+ * written to other objects, and thus, no need to retag. */
+ }
+ return;
+
+ case CONSTR_NOCAF_STATIC:
+ /* no need to put these on the static linked list, they don't need
+ * to be scavenged.
+ */
+ return;
+
+ default:
+ barf("evacuate(static): strange closure type %d", (int)(info->type));
+ }
+ }
+
+ bd = Bdescr((P_)q);
+
+ if (bd->gen_no > N) {
+ /* Can't evacuate this object, because it's in a generation
+ * older than the ones we're collecting. Let's hope that it's
+ * in gct->evac_step or older, or we will have to arrange to track
+ * this pointer using the mutable list.
+ */
+ if (bd->step < gct->evac_step) {
+ // nope
+ gct->failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
+ }
+ return;
+ }
+
+ if ((bd->flags & (BF_LARGE | BF_COMPACTED | BF_EVACUATED)) != 0) {
+
+ /* pointer into to-space: just return it. This normally
+ * shouldn't happen, but alllowing it makes certain things
+ * slightly easier (eg. the mutable list can contain the same
+ * object twice, for example).
+ */
+ if (bd->flags & BF_EVACUATED) {
+ if (bd->step < gct->evac_step) {
+ gct->failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
+ }
+ return;
+ }
+
+ /* evacuate large objects by re-linking them onto a different list.
+ */
+ if (bd->flags & BF_LARGE) {
+ info = get_itbl(q);
+ if (info->type == TSO &&
+ ((StgTSO *)q)->what_next == ThreadRelocated) {
+ q = (StgClosure *)((StgTSO *)q)->link;
+ *p = q;
+ goto loop;
+ }
+ evacuate_large((P_)q);
+ return;
+ }
+
+ /* If the object is in a step that we're compacting, then we
+ * need to use an alternative evacuate procedure.
+ */
+ if (bd->flags & BF_COMPACTED) {
+ if (!is_marked((P_)q,bd)) {
+ mark((P_)q,bd);
+ if (mark_stack_full()) {
+ mark_stack_overflowed = rtsTrue;
+ reset_mark_stack();
+ }
+ push_mark_stack((P_)q);
+ }
+ return;
+ }
+ }
+
+ stp = bd->step->to;
+
+ info = get_itbl(q);
+
+ switch (info->type) {
+
+ case WHITEHOLE:
+ goto loop;
+
+ case MUT_VAR_CLEAN:
+ case MUT_VAR_DIRTY:
+ case MVAR_CLEAN:
+ case MVAR_DIRTY:
+ copy(p,q,sizeW_fromITBL(info),stp);
+ return;
+
+ case CONSTR_0_1:
+ {
+ StgWord w = (StgWord)q->payload[0];
+ if (q->header.info == Czh_con_info &&
+ // unsigned, so always true: (StgChar)w >= MIN_CHARLIKE &&
+ (StgChar)w <= MAX_CHARLIKE) {
+ *p = TAG_CLOSURE(tag,
+ (StgClosure *)CHARLIKE_CLOSURE((StgChar)w)
+ );
+ }
+ if (q->header.info == Izh_con_info &&
+ (StgInt)w >= MIN_INTLIKE && (StgInt)w <= MAX_INTLIKE) {
+ *p = TAG_CLOSURE(tag,
+ (StgClosure *)INTLIKE_CLOSURE((StgInt)w)
+ );
+ }
+ else {
+ copy_tag(p,q,sizeofW(StgHeader)+1,stp,tag);
+ }
+ return;
+ }
+
+ case FUN_0_1:
+ case FUN_1_0:
+ case CONSTR_1_0:
+ copy_tag(p,q,sizeofW(StgHeader)+1,stp,tag);
+ return;
+
+ case THUNK_1_0:
+ case THUNK_0_1:
+ copy(p,q,sizeofW(StgThunk)+1,stp);
+ return;
+
+ case THUNK_1_1:
+ case THUNK_2_0:
+ case THUNK_0_2:
+#ifdef NO_PROMOTE_THUNKS
+ if (bd->gen_no == 0 &&
+ bd->step->no != 0 &&
+ bd->step->no == generations[bd->gen_no].n_steps-1) {
+ stp = bd->step;
+ }
+#endif
+ copy(p,q,sizeofW(StgThunk)+2,stp);
+ return;
+
+ case FUN_1_1:
+ case FUN_2_0:
+ case FUN_0_2:
+ case CONSTR_1_1:
+ case CONSTR_2_0:
+ copy_tag(p,q,sizeofW(StgHeader)+2,stp,tag);
+ return;
+
+ case CONSTR_0_2:
+ copy_tag(p,q,sizeofW(StgHeader)+2,stp,tag);
+ return;
+
+ case THUNK:
+ copy(p,q,thunk_sizeW_fromITBL(info),stp);
+ return;
+
+ case FUN:
+ case IND_PERM:
+ case IND_OLDGEN_PERM:
+ case WEAK:
+ case STABLE_NAME:
+ case CONSTR:
+ copy_tag(p,q,sizeW_fromITBL(info),stp,tag);
+ return;
+
+ case BCO:
+ copy(p,q,bco_sizeW((StgBCO *)q),stp);
+ return;
+
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ copyPart(p,q,BLACKHOLE_sizeW(),sizeofW(StgHeader),stp);
+ return;
+
+ case THUNK_SELECTOR:
+ eval_thunk_selector(p, (StgSelector *)q, rtsTrue);
+ return;
+
+ case IND:
+ case IND_OLDGEN:
+ // follow chains of indirections, don't evacuate them
+ q = ((StgInd*)q)->indirectee;
+ *p = q;
+ goto loop;
+
+ case RET_BCO:
+ case RET_SMALL:
+ case RET_BIG:
+ case RET_DYN:
+ case UPDATE_FRAME:
+ case STOP_FRAME:
+ case CATCH_FRAME:
+ case CATCH_STM_FRAME:
+ case CATCH_RETRY_FRAME:
+ case ATOMICALLY_FRAME:
+ // shouldn't see these
+ barf("evacuate: stack frame at %p\n", q);
+
+ case PAP:
+ copy(p,q,pap_sizeW((StgPAP*)q),stp);
+ return;
+
+ case AP:
+ copy(p,q,ap_sizeW((StgAP*)q),stp);
+ return;
+
+ case AP_STACK:
+ copy(p,q,ap_stack_sizeW((StgAP_STACK*)q),stp);
+ return;
+
+ case EVACUATED:
+ /* Already evacuated, just return the forwarding address.
+ * HOWEVER: if the requested destination generation (gct->evac_step) is
+ * older than the actual generation (because the object was
+ * already evacuated to a younger generation) then we have to
+ * set the gct->failed_to_evac flag to indicate that we couldn't
+ * manage to promote the object to the desired generation.
+ */
+ /*
+ * Optimisation: the check is fairly expensive, but we can often
+ * shortcut it if either the required generation is 0, or the
+ * current object (the EVACUATED) is in a high enough generation.
+ * We know that an EVACUATED always points to an object in the
+ * same or an older generation. stp is the lowest step that the
+ * current object would be evacuated to, so we only do the full
+ * check if stp is too low.
+ */
+ {
+ StgClosure *e = ((StgEvacuated*)q)->evacuee;
+ *p = e;
+ if (stp < gct->evac_step) { // optimisation
+ if (HEAP_ALLOCED(e) && Bdescr((P_)e)->step < gct->evac_step) {
+ gct->failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
+ }
+ }
+ return;
+ }
+
+ case ARR_WORDS:
+ // just copy the block
+ copy(p,q,arr_words_sizeW((StgArrWords *)q),stp);
+ return;
+
+ case MUT_ARR_PTRS_CLEAN:
+ case MUT_ARR_PTRS_DIRTY:
+ case MUT_ARR_PTRS_FROZEN:
+ case MUT_ARR_PTRS_FROZEN0:
+ // just copy the block
+ copy(p,q,mut_arr_ptrs_sizeW((StgMutArrPtrs *)q),stp);
+ return;
+
+ case TSO:
+ {
+ StgTSO *tso = (StgTSO *)q;
+
+ /* Deal with redirected TSOs (a TSO that's had its stack enlarged).
+ */
+ if (tso->what_next == ThreadRelocated) {
+ q = (StgClosure *)tso->link;
+ *p = q;
+ goto loop;
+ }
+
+ /* To evacuate a small TSO, we need to relocate the update frame
+ * list it contains.
+ */
+ {
+ StgTSO *new_tso;
+ StgPtr r, s;
+
+ copyPart(p,(StgClosure *)tso, tso_sizeW(tso), sizeofW(StgTSO), stp);
+ new_tso = (StgTSO *)*p;
+ move_TSO(tso, new_tso);
+ for (r = tso->sp, s = new_tso->sp;
+ r < tso->stack+tso->stack_size;) {
+ *s++ = *r++;
+ }
+ return;
+ }
+ }
+
+ case TREC_HEADER:
+ copy(p,q,sizeofW(StgTRecHeader),stp);
+ return;
+
+ case TVAR_WATCH_QUEUE:
+ copy(p,q,sizeofW(StgTVarWatchQueue),stp);
+ return;
+
+ case TVAR:
+ copy(p,q,sizeofW(StgTVar),stp);
+ return;
+
+ case TREC_CHUNK:
+ copy(p,q,sizeofW(StgTRecChunk),stp);
+ return;
+
+ case ATOMIC_INVARIANT:
+ copy(p,q,sizeofW(StgAtomicInvariant),stp);
+ return;
+
+ case INVARIANT_CHECK_QUEUE:
+ copy(p,q,sizeofW(StgInvariantCheckQueue),stp);
+ return;
+
+ default:
+ barf("evacuate: strange closure type %d", (int)(info->type));
+ }
+
+ barf("evacuate");
+}
#define REGPARM1
#endif
-REGPARM1 void evacuate (StgClosure **p);
+REGPARM1 void evacuate (StgClosure **p);
+REGPARM1 void evacuate0 (StgClosure **p);
extern lnat thunk_selector_depth;
StgLargeBitmap *large_bitmap,
nat size );
-static void scavenge_block (bdescr *bd, StgPtr scan);
-
/* Similar to scavenge_large_bitmap(), but we don't write back the
* pointers we get back from evacuate().
}
/* -----------------------------------------------------------------------------
- Scavenge a block from the given scan pointer up to bd->free.
-
- evac_step 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_step back to zero if we're
- scavenging a mutable object where eager promotion isn't such a good
- idea.
- -------------------------------------------------------------------------- */
-
-static void
-scavenge_block (bdescr *bd, StgPtr scan)
-{
- StgPtr p, q;
- StgInfoTable *info;
- step *saved_evac_step;
-
- p = scan;
-
- debugTrace(DEBUG_gc, "scavenging block %p (gen %d, step %d) @ %p",
- bd->start, bd->gen_no, bd->step->no, scan);
-
- gct->evac_step = bd->step;
- saved_evac_step = gct->evac_step;
- gct->failed_to_evac = rtsFalse;
-
- // 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) {
-
- 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:
- {
- rtsBool saved_eager_promotion = gct->eager_promotion;
-
- 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;
- }
-
- case FUN_2_0:
- scavenge_fun_srt(info);
- evacuate(&((StgClosure *)p)->payload[1]);
- evacuate(&((StgClosure *)p)->payload[0]);
- p += sizeofW(StgHeader) + 2;
- break;
-
- 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;
- }
-
- gen_obj:
- case CONSTR:
- case WEAK:
- case STABLE_NAME:
- {
- 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;
- }
-
- case BCO: {
- StgBCO *bco = (StgBCO *)p;
- evacuate((StgClosure **)&bco->instrs);
- evacuate((StgClosure **)&bco->literals);
- evacuate((StgClosure **)&bco->ptrs);
- p += bco_sizeW(bco);
- break;
- }
-
- 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: {
- rtsBool saved_eager_promotion = gct->eager_promotion;
-
- 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 SE_CAF_BLACKHOLE:
- case SE_BLACKHOLE:
- case BLACKHOLE:
- p += BLACKHOLE_sizeW();
- break;
-
- case THUNK_SELECTOR:
- {
- StgSelector *s = (StgSelector *)p;
- evacuate(&s->selectee);
- p += THUNK_SELECTOR_sizeW();
- break;
- }
-
- // A chunk of stack saved in a heap object
- case AP_STACK:
- {
- StgAP_STACK *ap = (StgAP_STACK *)p;
-
- evacuate(&ap->fun);
- scavenge_stack((StgPtr)ap->payload, (StgPtr)ap->payload + ap->size);
- p = (StgPtr)ap->payload + ap->size;
- break;
- }
-
- case PAP:
- p = scavenge_PAP((StgPAP *)p);
- break;
-
- case AP:
- p = scavenge_AP((StgAP *)p);
- break;
-
- case ARR_WORDS:
- // nothing to follow
- p += arr_words_sizeW((StgArrWords *)p);
- break;
-
- case MUT_ARR_PTRS_CLEAN:
- 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;
- }
-
- 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
- {
- StgPtr next;
-
- next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
- evacuate((StgClosure **)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;
- }
-
- case TSO:
- {
- StgTSO *tso = (StgTSO *)p;
- rtsBool saved_eager = gct->eager_promotion;
-
- gct->eager_promotion = rtsFalse;
- scavengeTSO(tso);
- gct->eager_promotion = saved_eager;
-
- if (gct->failed_to_evac) {
- tso->flags |= TSO_DIRTY;
- } else {
- tso->flags &= ~TSO_DIRTY;
- }
-
- gct->failed_to_evac = rtsTrue; // always on the mutable list
- p += tso_sizeW(tso);
- 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
- p += sizeofW(StgTVarWatchQueue);
- 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
- p += sizeofW(StgTVar);
- 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
- p += sizeofW(StgTRecHeader);
- break;
- }
-
- case TREC_CHUNK:
- {
- StgWord i;
- StgTRecChunk *tc = ((StgTRecChunk *) p);
- TRecEntry *e = &(tc -> entries[0]);
- gct->evac_step = 0;
- 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
- p += sizeofW(StgTRecChunk);
- 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
- p += sizeofW(StgAtomicInvariant);
- 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
- p += sizeofW(StgInvariantCheckQueue);
- break;
- }
-
- default:
- 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, &generations[bd->gen_no]);
- }
- }
- }
-
- debugTrace(DEBUG_gc, " scavenged %ld bytes", (bd->free - scan) * sizeof(W_));
-}
-
-/* -----------------------------------------------------------------------------
Scavenge everything on the mark stack.
This is slightly different from scavenge():
}
/* ----------------------------------------------------------------------------
+ Scavenge a block
+ ------------------------------------------------------------------------- */
+
+#define MINOR_GC
+#include "Scav.c-inc"
+#undef MINOR_GC
+#include "Scav.c-inc"
+
+/* ----------------------------------------------------------------------------
Find the oldest full block to scavenge, and scavenge it.
------------------------------------------------------------------------- */
// 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.
- scavenge_block(bd, bd->start);
+ if (N == 0) {
+ scavenge_block0(bd, bd->start);
+ } else {
+ scavenge_block(bd, bd->start);
+ }
push_scan_block(bd, ws);
return rtsTrue;
}
// scavenge everything up to the free pointer.
if (ws->scan != NULL && ws->scan < ws->scan_bd->free)
{
- scavenge_block(ws->scan_bd, ws->scan);
+ if (N == 0) {
+ scavenge_block0(ws->scan_bd, ws->scan);
+ } else {
+ scavenge_block(ws->scan_bd, ws->scan);
+ }
ws->scan = ws->scan_bd->free;
flag = rtsTrue;
}
--- /dev/null
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team 1998-2006
+ *
+ * Generational garbage collector: scavenging functions
+ *
+ * Documentation on the architecture of the Garbage Collector can be
+ * found in the online commentary:
+ *
+ * http://hackage.haskell.org/trac/ghc/wiki/Commentary/Rts/Storage/GC
+ *
+ * ---------------------------------------------------------------------------*/
+
+// This file is #included into Scav.c, twice: firstly with MINOR_GC
+// defined, the second time without.
+
+#ifdef MINOR_GC
+#define scavenge_block(a,b) scavenge_block0(a,b)
+#define evacuate(a) evacuate0(a)
+#else
+#undef scavenge_block
+#undef evacuate
+#endif
+
+static void scavenge_block (bdescr *bd, StgPtr scan);
+
+/* -----------------------------------------------------------------------------
+ Scavenge a block from the given scan pointer up to bd->free.
+
+ evac_step 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_step back to zero if we're
+ scavenging a mutable object where eager promotion isn't such a good
+ idea.
+ -------------------------------------------------------------------------- */
+
+static void
+scavenge_block (bdescr *bd, StgPtr scan)
+{
+ StgPtr p, q;
+ StgInfoTable *info;
+ step *saved_evac_step;
+
+ p = scan;
+
+ debugTrace(DEBUG_gc, "scavenging block %p (gen %d, step %d) @ %p",
+ bd->start, bd->gen_no, bd->step->no, scan);
+
+ gct->evac_step = bd->step;
+ saved_evac_step = gct->evac_step;
+ gct->failed_to_evac = rtsFalse;
+
+ // 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) {
+
+ 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:
+ {
+ rtsBool saved_eager_promotion = gct->eager_promotion;
+
+ 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;
+ }
+
+ case FUN_2_0:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ evacuate(&((StgClosure *)p)->payload[1]);
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_2_0:
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ 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:
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ evacuate(&((StgThunk *)p)->payload[0]);
+ p += sizeofW(StgThunk) + 1;
+ break;
+
+ case FUN_1_0:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ case CONSTR_1_0:
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_1:
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ p += sizeofW(StgThunk) + 1;
+ break;
+
+ case FUN_0_1:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ case CONSTR_0_1:
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_2:
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ p += sizeofW(StgThunk) + 2;
+ break;
+
+ case FUN_0_2:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ case CONSTR_0_2:
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_1:
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ evacuate(&((StgThunk *)p)->payload[0]);
+ p += sizeofW(StgThunk) + 2;
+ break;
+
+ case FUN_1_1:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ case CONSTR_1_1:
+ evacuate(&((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case FUN:
+#ifndef MINOR_GC
+ scavenge_fun_srt(info);
+#endif
+ goto gen_obj;
+
+ case THUNK:
+ {
+ StgPtr end;
+
+#ifndef MINOR_GC
+ scavenge_thunk_srt(info);
+#endif
+ 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;
+ }
+
+ gen_obj:
+ case CONSTR:
+ case WEAK:
+ case STABLE_NAME:
+ {
+ 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;
+ }
+
+ case BCO: {
+ StgBCO *bco = (StgBCO *)p;
+ evacuate((StgClosure **)&bco->instrs);
+ evacuate((StgClosure **)&bco->literals);
+ evacuate((StgClosure **)&bco->ptrs);
+ p += bco_sizeW(bco);
+ break;
+ }
+
+ 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: {
+ rtsBool saved_eager_promotion = gct->eager_promotion;
+
+ 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 SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ p += BLACKHOLE_sizeW();
+ break;
+
+ case THUNK_SELECTOR:
+ {
+ StgSelector *s = (StgSelector *)p;
+ evacuate(&s->selectee);
+ p += THUNK_SELECTOR_sizeW();
+ break;
+ }
+
+ // A chunk of stack saved in a heap object
+ case AP_STACK:
+ {
+ StgAP_STACK *ap = (StgAP_STACK *)p;
+
+ evacuate(&ap->fun);
+ scavenge_stack((StgPtr)ap->payload, (StgPtr)ap->payload + ap->size);
+ p = (StgPtr)ap->payload + ap->size;
+ break;
+ }
+
+ case PAP:
+ p = scavenge_PAP((StgPAP *)p);
+ break;
+
+ case AP:
+ p = scavenge_AP((StgAP *)p);
+ break;
+
+ case ARR_WORDS:
+ // nothing to follow
+ p += arr_words_sizeW((StgArrWords *)p);
+ break;
+
+ case MUT_ARR_PTRS_CLEAN:
+ 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;
+ }
+
+ 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
+ {
+ StgPtr next;
+
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ evacuate((StgClosure **)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;
+ }
+
+ case TSO:
+ {
+ StgTSO *tso = (StgTSO *)p;
+ rtsBool saved_eager = gct->eager_promotion;
+
+ gct->eager_promotion = rtsFalse;
+ scavengeTSO(tso);
+ gct->eager_promotion = saved_eager;
+
+ if (gct->failed_to_evac) {
+ tso->flags |= TSO_DIRTY;
+ } else {
+ tso->flags &= ~TSO_DIRTY;
+ }
+
+ gct->failed_to_evac = rtsTrue; // always on the mutable list
+ p += tso_sizeW(tso);
+ 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
+ p += sizeofW(StgTVarWatchQueue);
+ 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
+ p += sizeofW(StgTVar);
+ 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
+ p += sizeofW(StgTRecHeader);
+ break;
+ }
+
+ case TREC_CHUNK:
+ {
+ StgWord i;
+ StgTRecChunk *tc = ((StgTRecChunk *) p);
+ TRecEntry *e = &(tc -> entries[0]);
+ gct->evac_step = 0;
+ 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
+ p += sizeofW(StgTRecChunk);
+ 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
+ p += sizeofW(StgAtomicInvariant);
+ 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
+ p += sizeofW(StgInvariantCheckQueue);
+ break;
+ }
+
+ default:
+ 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, &generations[bd->gen_no]);
+ }
+ }
+ }
+
+ debugTrace(DEBUG_gc, " scavenged %ld bytes", (bd->free - scan) * sizeof(W_));
+}
projects / ghc-hetmet.git / commitdiff