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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=4 sw=2 et tw=80 ft=cpp:
*
* 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
#ifndef gc_Nursery_inl_h
#define gc_Nursery_inl_h
#include "gc/Nursery.h"
#include "gc/GCRuntime.h"
#include "gc/RelocationOverlay.h"
#include "js/TracingAPI.h"
#include "vm/JSContext.h"
#include "vm/NativeObject.h"
namespace js {
namespace gc {
struct Cell;
} // namespace gc
} // namespace js
inline JSRuntime* js::Nursery::runtime() const { return gc->rt; }
template <typename T>
bool js::Nursery::isInside(const SharedMem<T>& p) const {
return isInside(p.unwrap(/*safe - used for value in comparison above*/));
}
inline bool js::Nursery::shouldTenure(gc::Cell* cell) {
MOZ_ASSERT(semispaceEnabled());
MOZ_ASSERT(inCollectedRegion(cell));
size_t offset = fromSpace.offsetFromAddress(uintptr_t(cell));
MOZ_ASSERT(offset >=
fromSpace.offsetFromExclusiveAddress(fromSpace.startPosition_));
return offset <= tenureThreshold_;
}
inline bool js::Nursery::inCollectedRegion(gc::Cell* cell) const {
gc::ChunkBase* chunk = gc::detail::GetCellChunkBase(cell);
return chunk->getKind() == gc::ChunkKind::NurseryFromSpace;
}
inline bool js::Nursery::inCollectedRegion(void* ptr) const {
if (!semispaceEnabled()) {
return toSpace.isInside(ptr);
}
return fromSpace.isInside(ptr);
}
inline size_t js::Nursery::Space::offsetFromExclusiveAddress(
uintptr_t addr) const {
if ((addr & gc::ChunkMask) == 0) {
// |addr| points one past the end of the previous chunk.
return offsetFromAddress(addr - 1) + 1;
}
return offsetFromAddress(addr);
}
inline size_t js::Nursery::Space::offsetFromAddress(uintptr_t addr) const {
gc::ChunkBase* chunk =
gc::detail::GetCellChunkBase(reinterpret_cast<gc::Cell*>(addr));
MOZ_ASSERT(chunk->getKind() == kind);
MOZ_ASSERT(findChunkIndex(addr & ~gc::ChunkMask) == chunk->nurseryChunkIndex);
uint32_t offset = addr & gc::ChunkMask;
MOZ_ASSERT(offset >= sizeof(gc::ChunkBase));
return (chunk->nurseryChunkIndex << gc::ChunkShift) | offset;
}
MOZ_ALWAYS_INLINE /* static */ bool js::Nursery::getForwardedPointer(
js::gc::Cell** ref) {
js::gc::Cell* cell = (*ref);
MOZ_ASSERT(IsInsideNursery(cell));
if (!cell->isForwarded()) {
return false;
}
const gc::RelocationOverlay* overlay = gc::RelocationOverlay::fromCell(cell);
*ref = overlay->forwardingAddress();
return true;
}
inline void js::Nursery::maybeSetForwardingPointer(JSTracer* trc, void* oldData,
void* newData, bool direct) {
if (trc->isTenuringTracer()) {
setForwardingPointerWhileTenuring(oldData, newData, direct);
}
}
inline void js::Nursery::setForwardingPointerWhileTenuring(void* oldData,
void* newData,
bool direct) {
if (isInside(oldData)) {
setForwardingPointer(oldData, newData, direct);
}
}
inline void js::Nursery::setSlotsForwardingPointer(HeapSlot* oldSlots,
HeapSlot* newSlots,
uint32_t nslots) {
// Slot arrays always have enough space for a forwarding pointer, since the
// number of slots is never zero.
MOZ_ASSERT(nslots > 0);
setDirectForwardingPointer(oldSlots, newSlots);
}
inline void js::Nursery::setElementsForwardingPointer(ObjectElements* oldHeader,
ObjectElements* newHeader,
uint32_t capacity) {
// Only use a direct forwarding pointer if there is enough space for one.
setForwardingPointer(oldHeader->elements(), newHeader->elements(),
capacity > 0);
}
inline void js::Nursery::setForwardingPointer(void* oldData, void* newData,
bool direct) {
if (direct) {
setDirectForwardingPointer(oldData, newData);
return;
}
setIndirectForwardingPointer(oldData, newData);
}
inline void js::Nursery::setDirectForwardingPointer(void* oldData,
void* newData) {
MOZ_ASSERT(isInside(oldData));
MOZ_ASSERT_IF(isInside(newData), !inCollectedRegion(newData));
new (oldData) BufferRelocationOverlay{newData};
}
inline void* js::Nursery::tryAllocateCell(gc::AllocSite* site, size_t size,
JS::TraceKind kind) {
// Ensure there's enough space to replace the contents with a
// RelocationOverlay.
// MOZ_ASSERT(size >= sizeof(RelocationOverlay));
MOZ_ASSERT(size % gc::CellAlignBytes == 0);
MOZ_ASSERT(size_t(kind) < gc::NurseryTraceKinds);
MOZ_ASSERT_IF(kind == JS::TraceKind::String, canAllocateStrings());
MOZ_ASSERT_IF(kind == JS::TraceKind::BigInt, canAllocateBigInts());
void* ptr = tryAllocate(sizeof(gc::NurseryCellHeader) + size);
if (MOZ_UNLIKELY(!ptr)) {
return nullptr;
}
new (ptr) gc::NurseryCellHeader(site, kind);
void* cell =
reinterpret_cast<void*>(uintptr_t(ptr) + sizeof(gc::NurseryCellHeader));
if (!cell) {
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE(
"Successful allocation cannot result in nullptr");
}
// Update the allocation site. This code is also inlined in
// MacroAssembler::updateAllocSite.
uint32_t allocCount = site->incAllocCount();
if (allocCount == 1) {
pretenuringNursery.insertIntoAllocatedList(site);
}
MOZ_ASSERT_IF(site->isNormal(), site->isInAllocatedList());
gc::gcprobes::NurseryAlloc(cell, kind);
return cell;
}
inline void* js::Nursery::tryAllocate(size_t size) {
MOZ_ASSERT(isEnabled());
MOZ_ASSERT_IF(JS::RuntimeHeapIsBusy(), JS::RuntimeHeapIsMinorCollecting());
MOZ_ASSERT_IF(currentChunk() == startChunk(), position() >= startPosition());
MOZ_ASSERT(size % gc::CellAlignBytes == 0);
MOZ_ASSERT(position() % gc::CellAlignBytes == 0);
if (MOZ_UNLIKELY(currentEnd() < position() + size)) {
return nullptr;
}
void* ptr = reinterpret_cast<void*>(position());
if (!ptr) {
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE(
"Successful allocation cannot result in nullptr");
}
toSpace.position_ = position() + size;
DebugOnlyPoison(ptr, JS_ALLOCATED_NURSERY_PATTERN, size,
MemCheckKind::MakeUndefined);
return ptr;
}
inline bool js::Nursery::registerTrailer(PointerAndUint7 blockAndListID,
size_t nBytes) {
MOZ_ASSERT(toSpace.trailersAdded_.length() ==
toSpace.trailersRemoved_.length());
MOZ_ASSERT(nBytes > 0);
if (MOZ_UNLIKELY(!toSpace.trailersAdded_.append(blockAndListID))) {
return false;
}
if (MOZ_UNLIKELY(!toSpace.trailersRemoved_.append(nullptr))) {
toSpace.trailersAdded_.popBack();
return false;
}
// This is a clone of the logic in ::registerMallocedBuffer. It may be
// that some other heuristic is better, once we know more about the
// typical behaviour of wasm-GC applications.
toSpace.trailerBytes_ += nBytes;
if (MOZ_UNLIKELY(toSpace.trailerBytes_ > capacity() * 8)) {
requestMinorGC(JS::GCReason::NURSERY_TRAILERS);
}
return true;
}
inline void js::Nursery::unregisterTrailer(void* block) {
// Unlike removeMallocedBuffer this is only called during minor GC.
MOZ_ASSERT(fromSpace.trailersRemovedUsed_ <
fromSpace.trailersRemoved_.length());
fromSpace.trailersRemoved_[fromSpace.trailersRemovedUsed_] = block;
fromSpace.trailersRemovedUsed_++;
}
namespace js {
// The allocation methods below will not run the garbage collector. If the
// nursery cannot accomodate the allocation, the malloc heap will be used
// instead.
template <typename T>
static inline T* AllocateCellBuffer(Nursery& nursery, gc::Cell* cell,
uint32_t count) {
size_t nbytes = RoundUp(count * sizeof(T), sizeof(Value));
return static_cast<T*>(
nursery.allocateBuffer(cell->zone(), cell, nbytes, js::MallocArena));
}
template <typename T>
static inline T* AllocateCellBuffer(JSContext* cx, gc::Cell* cell,
uint32_t count) {
T* buffer = AllocateCellBuffer<T>(cx->nursery(), cell, count);
if (!buffer) {
ReportOutOfMemory(cx);
return nullptr;
}
return buffer;
}
// If this returns null then the old buffer will be left alone.
template <typename T>
static inline T* ReallocateCellBuffer(JSContext* cx, gc::Cell* cell,
T* oldBuffer, uint32_t oldCount,
uint32_t newCount, arena_id_t arenaId) {
size_t oldBytes = RoundUp(oldCount * sizeof(T), sizeof(Value));
size_t newBytes = RoundUp(newCount * sizeof(T), sizeof(Value));
T* buffer = static_cast<T*>(cx->nursery().reallocateBuffer(
cell->zone(), cell, oldBuffer, oldBytes, newBytes, arenaId));
if (!buffer) {
ReportOutOfMemory(cx);
}
return buffer;
}
} // namespace js
#endif /* gc_Nursery_inl_h */