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// Copyright 2020 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_HANDLES_LOCAL_HANDLES_INL_H_
#define V8_HANDLES_LOCAL_HANDLES_INL_H_
#include "src/base/sanitizer/msan.h"
#include "src/execution/isolate.h"
#include "src/execution/local-isolate.h"
#include "src/handles/local-handles.h"
namespace v8 {
namespace internal {
// static
V8_INLINE Address* LocalHandleScope::GetHandle(LocalHeap* local_heap,
Address value) {
if (local_heap->is_main_thread())
return LocalHandleScope::GetMainThreadHandle(local_heap, value);
LocalHandles* handles = local_heap->handles();
Address* result = handles->scope_.next;
if (result == handles->scope_.limit) {
result = handles->AddBlock();
}
DCHECK_LT(result, handles->scope_.limit);
handles->scope_.next++;
*result = value;
return result;
}
LocalHandleScope::LocalHandleScope(LocalIsolate* local_isolate)
: LocalHandleScope(local_isolate->heap()) {}
LocalHandleScope::LocalHandleScope(LocalHeap* local_heap) {
if (local_heap->is_main_thread()) {
OpenMainThreadScope(local_heap);
} else {
LocalHandles* handles = local_heap->handles();
local_heap_ = local_heap;
prev_next_ = handles->scope_.next;
prev_limit_ = handles->scope_.limit;
handles->scope_.level++;
}
}
LocalHandleScope::~LocalHandleScope() {
if (local_heap_->is_main_thread()) {
CloseMainThreadScope(local_heap_, prev_next_, prev_limit_);
} else {
CloseScope(local_heap_, prev_next_, prev_limit_);
}
}
template <typename T>
Handle<T> LocalHandleScope::CloseAndEscape(Handle<T> handle_value) {
HandleScopeData* current = &local_heap_->handles()->scope_;
T value = *handle_value;
// Throw away all handles in the current scope.
CloseScope(local_heap_, prev_next_, prev_limit_);
// Allocate one handle in the parent scope.
DCHECK(current->level > current->sealed_level);
Handle<T> result(value, local_heap_);
// Reinitialize the current scope (so that it's ready
// to be used or closed again).
prev_next_ = current->next;
prev_limit_ = current->limit;
current->level++;
return result;
}
void LocalHandleScope::CloseScope(LocalHeap* local_heap, Address* prev_next,
Address* prev_limit) {
LocalHandles* handles = local_heap->handles();
Address* old_limit = handles->scope_.limit;
handles->scope_.next = prev_next;
handles->scope_.limit = prev_limit;
handles->scope_.level--;
if (old_limit != handles->scope_.limit) {
handles->RemoveUnusedBlocks();
old_limit = handles->scope_.limit;
}
#ifdef ENABLE_HANDLE_ZAPPING
LocalHandles::ZapRange(handles->scope_.next, old_limit);
#endif
MSAN_ALLOCATED_UNINITIALIZED_MEMORY(
handles->scope_.next,
static_cast<size_t>(reinterpret_cast<Address>(old_limit) -
reinterpret_cast<Address>(handles->scope_.next)));
}
} // namespace internal
} // namespace v8
#endif // V8_HANDLES_LOCAL_HANDLES_INL_H_
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