/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.117 2001/08/08 13:45:02 simonmar Exp $
+ * $Id: GC.c,v 1.131 2002/03/07 17:53:05 keithw Exp $
*
* (c) The GHC Team 1998-1999
*
*
* ---------------------------------------------------------------------------*/
+#include "PosixSource.h"
#include "Rts.h"
#include "RtsFlags.h"
#include "RtsUtils.h"
#include "FrontPanel.h"
#endif
+#include "RetainerProfile.h"
+#include "LdvProfile.h"
+
/* STATIC OBJECT LIST.
*
* During GC:
static void scavenge_static ( void );
static void scavenge_mutable_list ( generation *g );
static void scavenge_mut_once_list ( generation *g );
-static void scavengeCAFs ( void );
#if 0 && defined(DEBUG)
static void gcCAFs ( void );
- free from-space in each step, and set from-space = to-space.
+ Locks held: sched_mutex
+
-------------------------------------------------------------------------- */
void
}
}
- scavengeCAFs();
+ /* follow roots from the CAF list (used by GHCi)
+ */
+ evac_gen = 0;
+ markCAFs(mark_root);
/* follow all the roots that the application knows about.
*/
}
}
+#ifdef PROFILING
+ // We call processHeapClosureForDead() on every closure destroyed during
+ // the current garbage collection, so we invoke LdvCensusForDead().
+ if (RtsFlags.ProfFlags.doHeapProfile == HEAP_BY_LDV
+ || RtsFlags.ProfFlags.bioSelector != NULL)
+ LdvCensusForDead(N);
+#endif
+
// NO MORE EVACUATION AFTER THIS POINT!
// Finally: compaction of the oldest generation.
if (major_gc && oldest_gen->steps[0].is_compacted) {
RtsFlags.GcFlags.minOldGenSize);
// minimum size for generation zero
- min_alloc = (RtsFlags.GcFlags.pcFreeHeap * max) / 200;
+ min_alloc = stg_max((RtsFlags.GcFlags.pcFreeHeap * max) / 200,
+ RtsFlags.GcFlags.minAllocAreaSize);
+
+ // Auto-enable compaction when the residency reaches a
+ // certain percentage of the maximum heap size (default: 30%).
+ if (RtsFlags.GcFlags.generations > 1 &&
+ (RtsFlags.GcFlags.compact ||
+ (max > 0 &&
+ oldest_gen->steps[0].n_blocks >
+ (RtsFlags.GcFlags.compactThreshold * max) / 100))) {
+ oldest_gen->steps[0].is_compacted = 1;
+// fprintf(stderr,"compaction: on\n", live);
+ } else {
+ oldest_gen->steps[0].is_compacted = 0;
+// fprintf(stderr,"compaction: off\n", live);
+ }
// if we're going to go over the maximum heap size, reduce the
// size of the generations accordingly. The calculation is
// different if compaction is turned on, because we don't need
// to double the space required to collect the old generation.
if (max != 0) {
- if (RtsFlags.GcFlags.compact) {
+
+ // this test is necessary to ensure that the calculations
+ // below don't have any negative results - we're working
+ // with unsigned values here.
+ if (max < min_alloc) {
+ heapOverflow();
+ }
+
+ if (oldest_gen->steps[0].is_compacted) {
if ( (size + (size - 1) * (gens - 2) * 2) + min_alloc > max ) {
size = (max - min_alloc) / ((gens - 1) * 2 - 1);
}
for (g = 0; g < gens; g++) {
generations[g].max_blocks = size;
}
-
- // Auto-enable compaction when the residency reaches a
- // certain percentage of the maximum heap size (default: 30%).
- if (RtsFlags.GcFlags.compact &&
- max > 0 &&
- oldest_gen->steps[0].n_blocks >
- (RtsFlags.GcFlags.compactThreshold * max) / 100) {
- oldest_gen->steps[0].is_compacted = 1;
-// fprintf(stderr,"compaction: on\n", live);
- } else {
- oldest_gen->steps[0].is_compacted = 0;
-// fprintf(stderr,"compaction: off\n", live);
- }
}
// Guess the amount of live data for stats.
*/
blocks = g0s0->n_to_blocks;
- if ( blocks * RtsFlags.GcFlags.oldGenFactor * 2 >
- RtsFlags.GcFlags.maxHeapSize ) {
+ if ( RtsFlags.GcFlags.maxHeapSize != 0 &&
+ blocks * RtsFlags.GcFlags.oldGenFactor * 2 >
+ RtsFlags.GcFlags.maxHeapSize ) {
long adjusted_blocks; // signed on purpose
int pc_free;
}
resizeNursery((nat)blocks);
+
+ } else {
+ // we might have added extra large blocks to the nursery, so
+ // resize back to minAllocAreaSize again.
+ resizeNursery(RtsFlags.GcFlags.minAllocAreaSize);
}
}
if (major_gc) { gcCAFs(); }
#endif
+#ifdef PROFILING
+ // resetStaticObjectForRetainerProfiling() must be called before
+ // zeroing below.
+ resetStaticObjectForRetainerProfiling();
+#endif
+
// zero the scavenged static object list
if (major_gc) {
zero_static_object_list(scavenged_static_objects);
// Reset the nursery
resetNurseries();
+ // let go of lock (so that it can be re-grabbed below).
+ RELEASE_LOCK(&sched_mutex);
+
// start any pending finalizers
scheduleFinalizers(old_weak_ptr_list);
// send exceptions to any threads which were about to die
resurrectThreads(resurrected_threads);
+ ACQUIRE_LOCK(&sched_mutex);
+
// Update the stable pointer hash table.
updateStablePtrTable(major_gc);
// restore enclosing cost centre
#ifdef PROFILING
- heapCensus();
CCCS = prev_CCS;
#endif
copy(StgClosure *src, nat size, step *stp)
{
P_ to, from, dest;
+#ifdef PROFILING
+ // @LDV profiling
+ nat size_org = size;
+#endif
TICK_GC_WORDS_COPIED(size);
/* Find out where we're going, using the handy "to" pointer in
dest = stp->hp;
stp->hp = to;
upd_evacuee(src,(StgClosure *)dest);
+#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(src, size_org);
+#endif
return (StgClosure *)dest;
}
*/
-static __inline__ StgClosure *
+static StgClosure *
copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, step *stp)
{
P_ dest, to, from;
+#ifdef PROFILING
+ // @LDV profiling
+ nat size_to_copy_org = size_to_copy;
+#endif
TICK_GC_WORDS_COPIED(size_to_copy);
if (stp->gen_no < evac_gen) {
dest = stp->hp;
stp->hp += size_to_reserve;
upd_evacuee(src,(StgClosure *)dest);
+#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.
+ // size_to_copy_org is wrong because the closure already occupies size_to_reserve
+ // words.
+ SET_EVACUAEE_FOR_LDV(src, size_to_reserve);
+ // fill the slop
+ if (size_to_reserve - size_to_copy_org > 0)
+ FILL_SLOP(stp->hp - 1, (int)(size_to_reserve - size_to_copy_org));
+#endif
return (StgClosure *)dest;
}
bdescr *bd = Bdescr(p);
step *stp;
- // should point to the beginning of the block
- ASSERT(((W_)p & BLOCK_MASK) == 0);
-
+ // object must be at the beginning of the block (or be a ByteArray)
+ ASSERT(get_itbl((StgClosure *)p)->type == ARR_WORDS ||
+ (((W_)p & BLOCK_MASK) == 0));
+
// already evacuated?
if (bd->flags & BF_EVACUATED) {
/* Don't forget to set the failed_to_evac flag if we didn't get
if (HEAP_ALLOCED(q)) {
bd = Bdescr((P_)q);
+ // not a group head: find the group head
+ if (bd->blocks == 0) { bd = bd->link; }
+
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
case CONSTR_1_1:
case CONSTR_0_2:
case CONSTR_STATIC:
+ case CONSTR_NOCAF_STATIC:
{
StgWord offset = info->layout.selector_offset;
// perform the selection!
q = selectee->payload[offset];
+ if (major_gc==rtsTrue) {TICK_GC_SEL_MAJOR();} else {TICK_GC_SEL_MINOR();}
/* if we're already in to-space, there's no need to continue
* with the evacuation, just update the source address with
thunk_selector_depth--;
goto selector_loop;
}
- }
- // otherwise, fall through...
+ } else {
+ TICK_GC_SEL_ABANDONED();
+ // and fall through...
+ }
# endif
case AP_UPD:
}
case IND_PERM:
- if (stp->gen_no != 0) {
- SET_INFO(((StgClosure *)p), &stg_IND_OLDGEN_PERM_info);
- }
+ if (stp->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_recordCreate()?
+ //
+ SET_INFO(((StgClosure *)p), &stg_IND_OLDGEN_PERM_info);
+#ifdef PROFILING
+ // @LDV profiling
+ // We pretend that p has just been created.
+ LDV_recordCreate((StgClosure *)p);
+#endif
+ }
// fall through
case IND_OLDGEN_PERM:
((StgIndOldGen *)p)->indirectee =
}
void
-scavengeCAFs( void )
+markCAFs( evac_fn evac )
{
StgIndStatic *c;
- evac_gen = 0;
for (c = (StgIndStatic *)caf_list; c != NULL;
c = (StgIndStatic *)c->static_link)
{
- c->indirectee = evacuate(c->indirectee);
+ evac(&c->indirectee);
}
}
#if (!defined(LAZY_BLACKHOLING)) && defined(DEBUG)
belch("Unexpected lazy BHing required at 0x%04x",(int)bh);
#endif
+#ifdef PROFILING
+ // @LDV profiling
+ // We pretend that bh is now dead.
+ LDV_recordDead_FILL_SLOP_DYNAMIC((StgClosure *)bh);
+#endif
SET_INFO(bh,&stg_BLACKHOLE_info);
+#ifdef PROFILING
+ // @LDV profiling
+ // We pretend that bh has just been created.
+ LDV_recordCreate(bh);
+#endif
}
update_frame = update_frame->link;
}
}
#endif
+#ifdef PROFILING
+ // @LDV profiling
+ // We pretend that bh is now dead.
+ LDV_recordDead_FILL_SLOP_DYNAMIC((StgClosure *)bh);
+#endif
+ //
+ // Todo: maybe use SET_HDR() and remove LDV_recordCreate()?
+ //
SET_INFO(bh,&stg_BLACKHOLE_info);
+#ifdef PROFILING
+ // @LDV profiling
+ // We pretend that bh has just been created.
+ LDV_recordCreate(bh);
+#endif
}
}