blob: 453637493c8edb45f155917a3509f56673696f7f [file] [log] [blame]
// Copyright 2019 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/heap/read-only-heap.h"
#include <cstring>
#include "src/base/once.h"
#include "src/heap/heap-inl.h"
#include "src/heap/spaces.h"
#include "src/snapshot/read-only-deserializer.h"
namespace v8 {
namespace internal {
#ifdef V8_SHARED_RO_HEAP
V8_DECLARE_ONCE(setup_ro_heap_once);
ReadOnlyHeap* shared_ro_heap = nullptr;
#endif
// static
void ReadOnlyHeap::SetUp(Isolate* isolate, ReadOnlyDeserializer* des) {
#ifdef V8_SHARED_RO_HEAP
void* isolate_ro_roots = reinterpret_cast<void*>(
isolate->roots_table().read_only_roots_begin().address());
base::CallOnce(&setup_ro_heap_once, [isolate, des, isolate_ro_roots]() {
shared_ro_heap = Init(isolate, des);
if (des != nullptr) {
std::memcpy(shared_ro_heap->read_only_roots_, isolate_ro_roots,
kEntriesCount * sizeof(Address));
}
});
isolate->heap()->SetUpFromReadOnlyHeap(shared_ro_heap);
if (des != nullptr) {
std::memcpy(isolate_ro_roots, shared_ro_heap->read_only_roots_,
kEntriesCount * sizeof(Address));
}
#else
Init(isolate, des);
#endif // V8_SHARED_RO_HEAP
}
void ReadOnlyHeap::OnCreateHeapObjectsComplete() {
DCHECK(!deserializing_);
#ifdef V8_SHARED_RO_HEAP
read_only_space_->Forget();
#endif
read_only_space_->MarkAsReadOnly();
}
// static
ReadOnlyHeap* ReadOnlyHeap::Init(Isolate* isolate, ReadOnlyDeserializer* des) {
auto* ro_heap = new ReadOnlyHeap(new ReadOnlySpace(isolate->heap()));
isolate->heap()->SetUpFromReadOnlyHeap(ro_heap);
if (des != nullptr) {
des->DeserializeInto(isolate);
ro_heap->deserializing_ = true;
#ifdef V8_SHARED_RO_HEAP
ro_heap->read_only_space_->Forget();
#endif
ro_heap->read_only_space_->MarkAsReadOnly();
}
return ro_heap;
}
void ReadOnlyHeap::OnHeapTearDown() {
#ifndef V8_SHARED_RO_HEAP
delete read_only_space_;
delete this;
#endif
}
// static
bool ReadOnlyHeap::Contains(Object object) {
return Page::FromAddress(object.ptr())->owner()->identity() == RO_SPACE;
}
} // namespace internal
} // namespace v8