blob: b9af2f935f4cfb360881efa89755b2b170e3e5e8 [file] [log] [blame]
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "platform/allocation.h"
#include "platform/assert.h"
#include "vm/base_isolate.h"
#include "vm/globals.h"
namespace dart {
// Forward declarations.
class Isolate;
class Thread;
// Stack resources subclass from this base class. The VM will ensure that the
// destructors of these objects are called before the stack is unwound past the
// objects location on the stack. Use stack resource objects if objects
// need to be destroyed even in the case of exceptions when a Longjump is done
// to a stack frame above the frame where these objects were allocated.
class StackResource {
explicit StackResource(Thread* thread) : thread_(NULL), previous_(NULL) {
virtual ~StackResource();
// Convenient access to the isolate of the thread of this resource.
Isolate* isolate() const;
// The thread that owns this resource.
Thread* thread() const { return thread_; }
// Destroy stack resources of thread until top exit frame.
static void Unwind(Thread* thread) { UnwindAbove(thread, NULL); }
// Destroy stack resources of thread above new_top, exclusive.
static void UnwindAbove(Thread* thread, StackResource* new_top);
void Init(Thread* thread);
Thread* thread_;
StackResource* previous_;
// Zone allocated objects cannot be individually deallocated, but have
// to rely on the destructor of Zone which is called when the Zone
// goes out of scope to reclaim memory.
class ZoneAllocated {
ZoneAllocated() {}
// Implicitly allocate the object in the current zone.
void* operator new(uword size);
// Allocate the object in the given zone, which must be the current zone.
void* operator new(uword size, Zone* zone);
// Ideally, the delete operator should be protected instead of
// public, but unfortunately the compiler sometimes synthesizes
// (unused) destructors for classes derived from ZoneObject, which
// require the operator to be visible. MSVC requires the delete
// operator to be public.
// Disallow explicit deallocation of nodes. Nodes can only be
// deallocated by invoking DeleteAll() on the zone they live in.
void operator delete(void* pointer) { UNREACHABLE(); }
// Within a NoSafepointScope, the thread must not reach any safepoint. Used
// around code that manipulates raw object pointers directly without handles.
#if defined(DEBUG)
class NoSafepointScope : public StackResource {
explicit NoSafepointScope(Thread* thread = nullptr);
#else // defined(DEBUG)
class NoSafepointScope : public ValueObject {
explicit NoSafepointScope(Thread* thread = nullptr) {}
#endif // defined(DEBUG)
} // namespace dart