Bug 1266457 - Update pointers in GC things in two phases when compacting r=terrence

This commit is contained in:
Jon Coppeard 2016-04-28 14:25:05 +01:00
Родитель 461e6dee16
Коммит 80c86a55a9
2 изменённых файлов: 87 добавлений и 66 удалений

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@ -8,6 +8,7 @@
#define gc_GCRuntime_h
#include "mozilla/Atomics.h"
#include "mozilla/EnumSet.h"
#include "jsfriendapi.h"
#include "jsgc.h"
@ -577,6 +578,8 @@ class ChainedIter
typedef HashMap<Value*, const char*, DefaultHasher<Value*>, SystemAllocPolicy> RootedValueMap;
using AllocKinds = mozilla::EnumSet<AllocKind>;
class GCRuntime
{
public:
@ -970,6 +973,7 @@ class GCRuntime
bool relocateArenas(Zone* zone, JS::gcreason::Reason reason, Arena*& relocatedListOut,
SliceBudget& sliceBudget);
void updateTypeDescrObjects(MovingTracer* trc, Zone* zone);
void updateCellPointers(MovingTracer* trc, Zone* zone, AllocKinds kinds, size_t bgTaskCount);
void updateAllCellPointers(MovingTracer* trc, Zone* zone);
void updatePointersToRelocatedCells(Zone* zone);
void protectAndHoldArenas(Arena* arenaList);

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@ -182,7 +182,6 @@
#include "mozilla/ArrayUtils.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/EnumSet.h"
#include "mozilla/MacroForEach.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Move.h"
@ -372,8 +371,6 @@ const uint32_t Arena::ThingsPerArena[] = {
#undef COUNT
using AllocKinds = mozilla::EnumSet<AllocKind>;
struct js::gc::FinalizePhase
{
gcstats::Phase statsPhase;
@ -2553,65 +2550,25 @@ struct ArenaListSegment
struct ArenasToUpdate
{
enum UpdateKind {
NONE = 0,
FOREGROUND = 1,
BACKGROUND = 2,
ALL = FOREGROUND | BACKGROUND
};
ArenasToUpdate(Zone* zone, UpdateKind kind);
ArenasToUpdate(Zone* zone, AllocKinds kinds);
bool done() { return kind == AllocKind::LIMIT; }
ArenaListSegment getArenasToUpdate(AutoLockHelperThreadState& lock, unsigned maxLength);
private:
UpdateKind kinds; // Selects which thing kinds to iterate
Zone* zone; // Zone to process
AllocKind kind; // Current alloc kind to process
Arena* arena; // Next arena to process
AllocKinds kinds; // Selects which thing kinds to update
Zone* zone; // Zone to process
AllocKind kind; // Current alloc kind to process
Arena* arena; // Next arena to process
AllocKind nextAllocKind(AllocKind i) { return AllocKind(uint8_t(i) + 1); }
UpdateKind updateKind(AllocKind kind);
bool shouldProcessKind(AllocKind kind);
Arena* next(AutoLockHelperThreadState& lock);
};
ArenasToUpdate::UpdateKind
ArenasToUpdate::updateKind(AllocKind kind)
{
MOZ_ASSERT(IsValidAllocKind(kind));
// GC things that do not contain pointers to cells we relocate don't need
// updating. Note that AllocKind::STRING is the only string kind which can
// be a rope and hence contain relocatable pointers.
if (kind == AllocKind::FAT_INLINE_STRING ||
kind == AllocKind::EXTERNAL_STRING ||
kind == AllocKind::SYMBOL)
{
return NONE;
}
// We try to update as many GC things in parallel as we can, but there are
// kinds for which this might not be safe:
// - we assume JSObjects that are foreground finalized are not safe to
// update in parallel
// - updating a shape touches child shapes in fixupShapeTreeAfterMovingGC()
if (!js::gc::IsBackgroundFinalized(kind) || IsShapeAllocKind(kind))
return FOREGROUND;
return BACKGROUND;
}
bool
ArenasToUpdate::shouldProcessKind(AllocKind kind)
{
return (updateKind(kind) & kinds) != 0;
}
ArenasToUpdate::ArenasToUpdate(Zone* zone, UpdateKind kinds)
ArenasToUpdate::ArenasToUpdate(Zone* zone, AllocKinds kinds)
: kinds(kinds), zone(zone), kind(AllocKind::FIRST), arena(nullptr)
{
MOZ_ASSERT(zone->isGCCompacting());
MOZ_ASSERT(!(kinds & ~ALL));
}
Arena*
@ -2624,7 +2581,7 @@ ArenasToUpdate::next(AutoLockHelperThreadState& lock)
// object and we just return when we find an arena.
for (; kind < AllocKind::LIMIT; kind = nextAllocKind(kind)) {
if (shouldProcessKind(kind)) {
if (kinds.contains(kind)) {
if (!arena)
arena = zone->arenas.getFirstArena(kind);
else
@ -2721,18 +2678,46 @@ CellUpdateBackgroundTaskCount()
return Min(Max(targetTaskCount, MinCellUpdateBackgroundTasks), MaxCellUpdateBackgroundTasks);
}
void
GCRuntime::updateAllCellPointers(MovingTracer* trc, Zone* zone)
static bool
CanUpdateKindInBackground(AllocKind kind) {
// We try to update as many GC things in parallel as we can, but there are
// kinds for which this might not be safe:
// - we assume JSObjects that are foreground finalized are not safe to
// update in parallel
// - updating a shape touches child shapes in fixupShapeTreeAfterMovingGC()
if (!js::gc::IsBackgroundFinalized(kind) || IsShapeAllocKind(kind))
return false;
return true;
}
static AllocKinds
ForegroundUpdateKinds(AllocKinds kinds)
{
AutoDisableProxyCheck noProxyCheck(rt); // These checks assert when run in parallel.
AllocKinds result;
for (AllocKind kind : kinds) {
if (!CanUpdateKindInBackground(kind))
result += kind;
}
return result;
}
size_t bgTaskCount = CellUpdateBackgroundTaskCount();
void
GCRuntime::updateTypeDescrObjects(MovingTracer* trc, Zone* zone)
{
zone->typeDescrObjects.sweep();
for (auto r = zone->typeDescrObjects.all(); !r.empty(); r.popFront())
UpdateCellPointers(trc, r.front().get());
}
ArenasToUpdate
fgArenas(zone, bgTaskCount == 0 ? ArenasToUpdate::ALL : ArenasToUpdate::FOREGROUND);
ArenasToUpdate
bgArenas(zone, bgTaskCount == 0 ? ArenasToUpdate::NONE : ArenasToUpdate::BACKGROUND);
void
GCRuntime::updateCellPointers(MovingTracer* trc, Zone* zone, AllocKinds kinds, size_t bgTaskCount)
{
AllocKinds fgKinds = bgTaskCount == 0 ? kinds : ForegroundUpdateKinds(kinds);
AllocKinds bgKinds = kinds - fgKinds;
ArenasToUpdate fgArenas(zone, fgKinds);
ArenasToUpdate bgArenas(zone, bgKinds);
Maybe<UpdatePointersTask> fgTask;
Maybe<UpdatePointersTask> bgTasks[MaxCellUpdateBackgroundTasks];
@ -2760,12 +2745,48 @@ GCRuntime::updateAllCellPointers(MovingTracer* trc, Zone* zone)
}
}
static const AllocKinds UpdatePhaseMisc {
AllocKind::SCRIPT,
AllocKind::LAZY_SCRIPT,
AllocKind::SHAPE,
AllocKind::BASE_SHAPE,
AllocKind::ACCESSOR_SHAPE,
AllocKind::OBJECT_GROUP,
AllocKind::STRING,
AllocKind::JITCODE
};
static const AllocKinds UpdatePhaseObjects {
AllocKind::FUNCTION,
AllocKind::FUNCTION_EXTENDED,
AllocKind::OBJECT0,
AllocKind::OBJECT0_BACKGROUND,
AllocKind::OBJECT2,
AllocKind::OBJECT2_BACKGROUND,
AllocKind::OBJECT4,
AllocKind::OBJECT4_BACKGROUND,
AllocKind::OBJECT8,
AllocKind::OBJECT8_BACKGROUND,
AllocKind::OBJECT12,
AllocKind::OBJECT12_BACKGROUND,
AllocKind::OBJECT16,
AllocKind::OBJECT16_BACKGROUND
};
void
GCRuntime::updateTypeDescrObjects(MovingTracer* trc, Zone* zone)
GCRuntime::updateAllCellPointers(MovingTracer* trc, Zone* zone)
{
zone->typeDescrObjects.sweep();
for (auto r = zone->typeDescrObjects.all(); !r.empty(); r.popFront())
UpdateCellPointers(trc, r.front().get());
AutoDisableProxyCheck noProxyCheck(rt); // These checks assert when run in parallel.
size_t bgTaskCount = CellUpdateBackgroundTaskCount();
updateCellPointers(trc, zone, UpdatePhaseMisc, bgTaskCount);
// Update TypeDescrs before all other objects as typed objects access these
// objects when we trace them.
updateTypeDescrObjects(trc, zone);
updateCellPointers(trc, zone, UpdatePhaseObjects, bgTaskCount);
}
/*
@ -2789,10 +2810,6 @@ GCRuntime::updatePointersToRelocatedCells(Zone* zone)
JSCompartment::fixupCrossCompartmentWrappersAfterMovingGC(&trc);
rt->spsProfiler.fixupStringsMapAfterMovingGC();
// Update TypeDescrs before all other objects as typed objects access these
// objects when we trace them.
updateTypeDescrObjects(&trc, zone);
// Iterate through all cells that can contain relocatable pointers to update
// them. Since updating each cell is independent we try to parallelize this
// as much as possible.