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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* Public header for allocating memory associated with GC things.
*/
#ifndef gc_ZoneAllocator_h
#define gc_ZoneAllocator_h
#include "mozilla/Maybe.h"
#include "jsfriendapi.h"
#include "jstypes.h"
#include "gc/Cell.h"
#include "gc/Scheduling.h"
#include "js/GCAPI.h"
#include "js/shadow/Zone.h" // JS::shadow::Zone
#include "vm/MallocProvider.h"
namespace JS {
class JS_PUBLIC_API Zone;
} // namespace JS
namespace js {
class ZoneAllocator;
#ifdef DEBUG
bool CurrentThreadIsGCFinalizing();
#endif
namespace gc {
void MaybeMallocTriggerZoneGC(JSRuntime* rt, ZoneAllocator* zoneAlloc,
const HeapSize& heap,
const HeapThreshold& threshold,
JS::GCReason reason);
}
// Base class of JS::Zone that provides malloc memory allocation and accounting.
class ZoneAllocator : public JS::shadow::Zone,
public js::MallocProvider<JS::Zone> {
protected:
explicit ZoneAllocator(JSRuntime* rt, Kind kind);
~ZoneAllocator();
void fixupAfterMovingGC();
public:
static ZoneAllocator* from(JS::Zone* zone) {
// This is a safe upcast, but the compiler hasn't seen the definition yet.
return reinterpret_cast<ZoneAllocator*>(zone);
}
[[nodiscard]] void* onOutOfMemory(js::AllocFunction allocFunc,
arena_id_t arena, size_t nbytes,
void* reallocPtr = nullptr);
void reportAllocationOverflow() const;
void updateSchedulingStateOnGCStart();
void updateGCStartThresholds(gc::GCRuntime& gc);
void setGCSliceThresholds(gc::GCRuntime& gc, bool waitingOnBGTask);
void clearGCSliceThresholds();
// Memory accounting APIs for malloc memory owned by GC cells.
void addCellMemory(js::gc::Cell* cell, size_t nbytes, js::MemoryUse use) {
MOZ_ASSERT(cell);
MOZ_ASSERT(nbytes);
mallocHeapSize.addBytes(nbytes);
#ifdef DEBUG
mallocTracker.trackGCMemory(cell, nbytes, use);
#endif
maybeTriggerGCOnMalloc();
}
void removeCellMemory(js::gc::Cell* cell, size_t nbytes, js::MemoryUse use,
bool updateRetainedSize = false) {
MOZ_ASSERT(cell);
MOZ_ASSERT(nbytes);
MOZ_ASSERT_IF(CurrentThreadIsGCFinalizing(), updateRetainedSize);
mallocHeapSize.removeBytes(nbytes, updateRetainedSize);
#ifdef DEBUG
mallocTracker.untrackGCMemory(cell, nbytes, use);
#endif
}
void swapCellMemory(js::gc::Cell* a, js::gc::Cell* b, js::MemoryUse use) {
#ifdef DEBUG
mallocTracker.swapGCMemory(a, b, use);
#endif
}
void registerNonGCMemory(void* mem, MemoryUse use) {
#ifdef DEBUG
return mallocTracker.registerNonGCMemory(mem, use);
#endif
}
void unregisterNonGCMemory(void* mem, MemoryUse use) {
#ifdef DEBUG
return mallocTracker.unregisterNonGCMemory(mem, use);
#endif
}
void moveOtherMemory(void* dst, void* src, MemoryUse use) {
#ifdef DEBUG
return mallocTracker.moveNonGCMemory(dst, src, use);
#endif
}
void incNonGCMemory(void* mem, size_t nbytes, MemoryUse use) {
MOZ_ASSERT(nbytes);
mallocHeapSize.addBytes(nbytes);
#ifdef DEBUG
mallocTracker.incNonGCMemory(mem, nbytes, use);
#endif
maybeTriggerGCOnMalloc();
}
void decNonGCMemory(void* mem, size_t nbytes, MemoryUse use,
bool updateRetainedSize) {
MOZ_ASSERT(nbytes);
mallocHeapSize.removeBytes(nbytes, updateRetainedSize);
#ifdef DEBUG
mallocTracker.decNonGCMemory(mem, nbytes, use);
#endif
}
// Account for allocations that may be referenced by more than one GC thing.
bool addSharedMemory(void* mem, size_t nbytes, MemoryUse use);
void removeSharedMemory(void* mem, size_t nbytes, MemoryUse use);
void incJitMemory(size_t nbytes) {
MOZ_ASSERT(nbytes);
jitHeapSize.addBytes(nbytes);
maybeTriggerZoneGC(jitHeapSize, jitHeapThreshold,
JS::GCReason::TOO_MUCH_JIT_CODE);
}
void decJitMemory(size_t nbytes) {
MOZ_ASSERT(nbytes);
jitHeapSize.removeBytes(nbytes, true);
}
// Check malloc allocation threshold and trigger a zone GC if necessary.
void maybeTriggerGCOnMalloc() {
maybeTriggerZoneGC(mallocHeapSize, mallocHeapThreshold,
JS::GCReason::TOO_MUCH_MALLOC);
}
private:
void maybeTriggerZoneGC(const js::gc::HeapSize& heap,
const js::gc::HeapThreshold& threshold,
JS::GCReason reason) {
if (heap.bytes() >= threshold.startBytes()) {
gc::MaybeMallocTriggerZoneGC(runtimeFromAnyThread(), this, heap,
threshold, reason);
}
}
void updateCollectionRate(mozilla::TimeDuration mainThreadGCTime,
size_t initialBytesForAllZones);
void updateAllocationRate(mozilla::TimeDuration mutatorTime);
public:
// The size of allocated GC arenas in this zone.
gc::PerZoneGCHeapSize gcHeapSize;
// Threshold used to trigger GC based on GC heap size.
gc::GCHeapThreshold gcHeapThreshold;
// Amount of malloc data owned by tenured GC things in this zone, including
// external allocations supplied by JS::AddAssociatedMemory.
gc::HeapSize mallocHeapSize;
// Threshold used to trigger GC based on malloc allocations.
gc::MallocHeapThreshold mallocHeapThreshold;
// Amount of exectuable JIT code owned by GC things in this zone.
gc::HeapSize jitHeapSize;
// Threshold used to trigger GC based on JIT allocations.
gc::JitHeapThreshold jitHeapThreshold;
// Use counts for memory that can be referenced by more than one GC thing.
// Memory recorded here is also recorded in mallocHeapSize. This structure
// is used to avoid over-counting in mallocHeapSize.
gc::SharedMemoryMap sharedMemoryUseCounts;
// Collection rate estimate for this zone in MB/s, and state used to calculate
// it. Updated every time this zone is collected.
MainThreadData<mozilla::Maybe<double>> smoothedCollectionRate;
MainThreadOrGCTaskData<mozilla::TimeDuration> perZoneGCTime;
// Allocation rate estimate in MB/s of mutator time, and state used to
// calculate it.
MainThreadData<mozilla::Maybe<double>> smoothedAllocationRate;
MainThreadData<size_t> prevGCHeapSize;
private:
#ifdef DEBUG
// In debug builds, malloc allocations can be tracked to make debugging easier
// (possible?) if allocation and free sizes don't balance.
gc::MemoryTracker mallocTracker;
#endif
friend class gc::GCRuntime;
};
// Whether memory is associated with a single cell or whether it is associated
// with the zone as a whole (for memory used by the system).
enum class TrackingKind { Cell, Zone };
/*
* Allocation policy that performs memory tracking for malloced memory. This
* should be used for all containers associated with a GC thing or a zone.
*
* Since it doesn't hold a JSContext (those may not live long enough), it can't
* report out-of-memory conditions itself; the caller must check for OOM and
* take the appropriate action.
*
*/
template <TrackingKind kind>
class TrackedAllocPolicy : public MallocProvider<TrackedAllocPolicy<kind>> {
ZoneAllocator* zone_;
#ifdef DEBUG
friend class js::gc::MemoryTracker; // Can clear |zone_| on merge.
#endif
public:
MOZ_IMPLICIT TrackedAllocPolicy(ZoneAllocator* z) : zone_(z) {
zone()->registerNonGCMemory(this, MemoryUse::TrackedAllocPolicy);
}
MOZ_IMPLICIT TrackedAllocPolicy(JS::Zone* z)
: TrackedAllocPolicy(ZoneAllocator::from(z)) {}
TrackedAllocPolicy(TrackedAllocPolicy& other)
: TrackedAllocPolicy(other.zone_) {}
TrackedAllocPolicy(TrackedAllocPolicy&& other) : zone_(other.zone_) {
zone()->moveOtherMemory(this, &other, MemoryUse::TrackedAllocPolicy);
other.zone_ = nullptr;
}
~TrackedAllocPolicy() {
if (zone_) {
zone_->unregisterNonGCMemory(this, MemoryUse::TrackedAllocPolicy);
}
}
TrackedAllocPolicy& operator=(const TrackedAllocPolicy& other) {
zone()->unregisterNonGCMemory(this, MemoryUse::TrackedAllocPolicy);
zone_ = other.zone();
zone()->registerNonGCMemory(this, MemoryUse::TrackedAllocPolicy);
return *this;
}
TrackedAllocPolicy& operator=(TrackedAllocPolicy&& other) {
MOZ_ASSERT(this != &other);
zone()->unregisterNonGCMemory(this, MemoryUse::TrackedAllocPolicy);
zone_ = other.zone();
zone()->moveOtherMemory(this, &other, MemoryUse::TrackedAllocPolicy);
other.zone_ = nullptr;
return *this;
}
// Public methods required to fulfill the AllocPolicy interface.
template <typename T>
void free_(T* p, size_t numElems) {
if (p) {
decMemory(numElems * sizeof(T));
js_free(p);
}
}
[[nodiscard]] bool checkSimulatedOOM() const {
return !js::oom::ShouldFailWithOOM();
}
void reportAllocOverflow() const { reportAllocationOverflow(); }
// Internal methods called by the MallocProvider implementation.
[[nodiscard]] void* onOutOfMemory(js::AllocFunction allocFunc,
arena_id_t arena, size_t nbytes,
void* reallocPtr = nullptr) {
return zone()->onOutOfMemory(allocFunc, arena, nbytes, reallocPtr);
}
void reportAllocationOverflow() const { zone()->reportAllocationOverflow(); }
void updateMallocCounter(size_t nbytes) {
zone()->incNonGCMemory(this, nbytes, MemoryUse::TrackedAllocPolicy);
}
private:
ZoneAllocator* zone() const {
MOZ_ASSERT(zone_);
return zone_;
}
void decMemory(size_t nbytes);
};
using ZoneAllocPolicy = TrackedAllocPolicy<TrackingKind::Zone>;
using CellAllocPolicy = TrackedAllocPolicy<TrackingKind::Cell>;
// Functions for memory accounting on the zone.
// Associate malloc memory with a GC thing. This call should be matched by a
// following call to RemoveCellMemory with the same size and use. The total
// amount of malloc memory associated with a zone is used to trigger GC.
//
// You should use InitReservedSlot / InitObjectPrivate in preference to this
// where possible.
inline void AddCellMemory(gc::TenuredCell* cell, size_t nbytes, MemoryUse use) {
if (nbytes) {
ZoneAllocator::from(cell->zone())->addCellMemory(cell, nbytes, use);
}
}
inline void AddCellMemory(gc::Cell* cell, size_t nbytes, MemoryUse use) {
if (cell->isTenured()) {
AddCellMemory(&cell->asTenured(), nbytes, use);
}
}
// Remove association between malloc memory and a GC thing. This call should
// follow a call to AddCellMemory with the same size and use.
inline void RemoveCellMemory(gc::TenuredCell* cell, size_t nbytes,
MemoryUse use) {
MOZ_ASSERT(!CurrentThreadIsGCFinalizing(),
"Use GCContext methods to remove associated memory in finalizers");
if (nbytes) {
auto zoneBase = ZoneAllocator::from(cell->zoneFromAnyThread());
zoneBase->removeCellMemory(cell, nbytes, use, false);
}
}
inline void RemoveCellMemory(gc::Cell* cell, size_t nbytes, MemoryUse use) {
if (cell->isTenured()) {
RemoveCellMemory(&cell->asTenured(), nbytes, use);
}
}
} // namespace js
#endif // gc_ZoneAllocator_h