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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.
#include "src/snapshot/builtin-deserializer-allocator.h"
#include "src/heap/heap-inl.h"
#include "src/interpreter/interpreter.h"
#include "src/snapshot/builtin-deserializer.h"
#include "src/snapshot/deserializer.h"
namespace v8 {
namespace internal {
using interpreter::Bytecodes;
using interpreter::Interpreter;
BuiltinDeserializerAllocator::BuiltinDeserializerAllocator(
Deserializer<BuiltinDeserializerAllocator>* deserializer)
: deserializer_(deserializer) {}
Address BuiltinDeserializerAllocator::Allocate(AllocationSpace space,
int size) {
const int code_object_id = deserializer()->CurrentCodeObjectId();
DCHECK_NE(BuiltinDeserializer::kNoCodeObjectId, code_object_id);
DCHECK_EQ(CODE_SPACE, space);
DCHECK_EQ(deserializer()->ExtractCodeObjectSize(code_object_id), size);
#ifdef DEBUG
RegisterCodeObjectAllocation(code_object_id);
#endif
DCHECK(Builtins::IsBuiltinId(code_object_id));
Object* obj = isolate()->builtins()->builtin(code_object_id);
DCHECK(Internals::HasHeapObjectTag(obj));
return HeapObject::cast(obj)->address();
}
Heap::Reservation
BuiltinDeserializerAllocator::CreateReservationsForEagerBuiltins() {
Heap::Reservation result;
// Reservations for builtins.
// DeserializeLazy is always the first builtin reservation (to simplify logic
// in InitializeBuiltinsTable).
{
DCHECK(!Builtins::IsLazy(Builtins::kDeserializeLazy));
uint32_t builtin_size =
deserializer()->ExtractCodeObjectSize(Builtins::kDeserializeLazy);
DCHECK_LE(builtin_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
result.push_back({builtin_size, kNullAddress, kNullAddress});
}
for (int i = 0; i < Builtins::builtin_count; i++) {
if (i == Builtins::kDeserializeLazy) continue;
// Skip lazy builtins. These will be replaced by the DeserializeLazy code
// object in InitializeFromReservations and thus require no reserved space.
if (deserializer()->IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
continue;
}
uint32_t builtin_size = deserializer()->ExtractCodeObjectSize(i);
DCHECK_LE(builtin_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
result.push_back({builtin_size, kNullAddress, kNullAddress});
}
return result;
}
void BuiltinDeserializerAllocator::InitializeBuiltinFromReservation(
const Heap::Chunk& chunk, int builtin_id) {
DCHECK_EQ(deserializer()->ExtractCodeObjectSize(builtin_id), chunk.size);
DCHECK_EQ(chunk.size, chunk.end - chunk.start);
SkipList::Update(chunk.start, chunk.size);
isolate()->builtins()->set_builtin(builtin_id,
HeapObject::FromAddress(chunk.start));
#ifdef DEBUG
RegisterCodeObjectReservation(builtin_id);
#endif
}
void BuiltinDeserializerAllocator::InitializeFromReservations(
const Heap::Reservation& reservation) {
DCHECK(!AllowHeapAllocation::IsAllowed());
// Initialize the builtins table.
Builtins* builtins = isolate()->builtins();
int reservation_index = 0;
// Other builtins can be replaced by DeserializeLazy so it may not be lazy.
// It always occupies the first reservation slot.
{
DCHECK(!Builtins::IsLazy(Builtins::kDeserializeLazy));
InitializeBuiltinFromReservation(reservation[reservation_index],
Builtins::kDeserializeLazy);
reservation_index++;
}
for (int i = 0; i < Builtins::builtin_count; i++) {
if (i == Builtins::kDeserializeLazy) continue;
if (deserializer()->IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
builtins->set_builtin(
i, builtins->builtin(builtins->LazyDeserializerForBuiltin(i)));
} else {
InitializeBuiltinFromReservation(reservation[reservation_index], i);
reservation_index++;
}
}
DCHECK_EQ(reservation.size(), reservation_index);
}
void BuiltinDeserializerAllocator::ReserveAndInitializeBuiltinsTableForBuiltin(
int builtin_id) {
DCHECK(AllowHeapAllocation::IsAllowed());
DCHECK(isolate()->builtins()->is_initialized());
DCHECK(Builtins::IsBuiltinId(builtin_id));
DCHECK(!Builtins::IsLazyDeserializer(builtin_id));
DCHECK(Builtins::IsLazyDeserializer(
isolate()->builtins()->builtin(builtin_id)->builtin_index()));
const uint32_t builtin_size =
deserializer()->ExtractCodeObjectSize(builtin_id);
DCHECK_LE(builtin_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
Handle<HeapObject> o =
isolate()->factory()->NewCodeForDeserialization(builtin_size);
// Note: After this point and until deserialization finishes, heap allocation
// is disallowed. We currently can't safely assert this since we'd need to
// pass the DisallowHeapAllocation scope out of this function.
// Write the allocated filler object into the builtins table. It will be
// returned by our custom Allocate method below once needed.
isolate()->builtins()->set_builtin(builtin_id, *o);
#ifdef DEBUG
RegisterCodeObjectReservation(builtin_id);
#endif
}
#ifdef DEBUG
void BuiltinDeserializerAllocator::RegisterCodeObjectReservation(
int code_object_id) {
const auto result = unused_reservations_.emplace(code_object_id);
CHECK(result.second); // False, iff builtin_id was already present in set.
}
void BuiltinDeserializerAllocator::RegisterCodeObjectAllocation(
int code_object_id) {
const size_t removed_elems = unused_reservations_.erase(code_object_id);
CHECK_EQ(removed_elems, 1);
}
bool BuiltinDeserializerAllocator::ReservationsAreFullyUsed() const {
// Not 100% precise but should be good enough.
return unused_reservations_.empty();
}
#endif // DEBUG
Isolate* BuiltinDeserializerAllocator::isolate() const {
return deserializer()->isolate();
}
BuiltinDeserializer* BuiltinDeserializerAllocator::deserializer() const {
return static_cast<BuiltinDeserializer*>(deserializer_);
}
} // namespace internal
} // namespace v8
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