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// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_SNAPSHOT_DEFAULT_DESERIALIZER_ALLOCATOR_H_
#define V8_SNAPSHOT_DEFAULT_DESERIALIZER_ALLOCATOR_H_
#include "src/globals.h"
#include "src/heap/heap.h"
#include "src/snapshot/serializer-common.h"
namespace v8 {
namespace internal {
template <class AllocatorT>
class Deserializer;
class BuiltinDeserializer;
class StartupDeserializer;
class DefaultDeserializerAllocator final {
public:
DefaultDeserializerAllocator(
Deserializer<DefaultDeserializerAllocator>* deserializer);
// ------- Allocation Methods -------
// Methods related to memory allocation during deserialization.
Address Allocate(AllocationSpace space, int size);
void MoveToNextChunk(AllocationSpace space);
void SetAlignment(AllocationAlignment alignment) {
DCHECK_EQ(kWordAligned, next_alignment_);
DCHECK_LE(kWordAligned, alignment);
DCHECK_LE(alignment, kDoubleUnaligned);
next_alignment_ = static_cast<AllocationAlignment>(alignment);
}
HeapObject* GetMap(uint32_t index);
HeapObject* GetLargeObject(uint32_t index);
HeapObject* GetObject(AllocationSpace space, uint32_t chunk_index,
uint32_t chunk_offset);
// ------- Reservation Methods -------
// Methods related to memory reservations (prior to deserialization).
void DecodeReservation(Vector<const SerializedData::Reservation> res);
bool ReserveSpace();
// Atomically reserves space for the two given deserializers. Guarantees
// reservation for both without garbage collection in-between.
static bool ReserveSpace(StartupDeserializer* startup_deserializer,
BuiltinDeserializer* builtin_deserializer);
bool ReservationsAreFullyUsed() const;
// ------- Misc Utility Methods -------
void RegisterDeserializedObjectsForBlackAllocation();
private:
Isolate* isolate() const;
// Raw allocation without considering alignment.
Address AllocateRaw(AllocationSpace space, int size);
private:
static constexpr int kNumberOfPreallocatedSpaces =
SerializerDeserializer::kNumberOfPreallocatedSpaces;
static constexpr int kNumberOfSpaces =
SerializerDeserializer::kNumberOfSpaces;
// The address of the next object that will be allocated in each space.
// Each space has a number of chunks reserved by the GC, with each chunk
// fitting into a page. Deserialized objects are allocated into the
// current chunk of the target space by bumping up high water mark.
Heap::Reservation reservations_[kNumberOfSpaces];
uint32_t current_chunk_[kNumberOfPreallocatedSpaces];
Address high_water_[kNumberOfPreallocatedSpaces];
// The alignment of the next allocation.
AllocationAlignment next_alignment_ = kWordAligned;
// All required maps are pre-allocated during reservation. {next_map_index_}
// stores the index of the next map to return from allocation.
uint32_t next_map_index_ = 0;
std::vector<Address> allocated_maps_;
// Allocated large objects are kept in this map and may be fetched later as
// back-references.
std::vector<HeapObject*> deserialized_large_objects_;
// The current deserializer.
Deserializer<DefaultDeserializerAllocator>* const deserializer_;
DISALLOW_COPY_AND_ASSIGN(DefaultDeserializerAllocator)
};
} // namespace internal
} // namespace v8
#endif // V8_SNAPSHOT_DEFAULT_DESERIALIZER_ALLOCATOR_H_
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