blob: d11f988f08d8fe2ba5ff490751a8581d4add6a23 [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.
#ifndef RUNTIME_VM_ALLOCATION_H_
#define RUNTIME_VM_ALLOCATION_H_
#include "platform/allocation.h"
#include "platform/assert.h"
#include "vm/globals.h"
namespace dart {
// Forward declarations.
class ThreadState;
class Zone;
// 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 {
public:
explicit StackResource(ThreadState* thread)
: thread_(nullptr), previous_(nullptr) {
Init(thread);
}
virtual ~StackResource();
// The thread that owns this resource.
ThreadState* thread() const { return thread_; }
// Destroy stack resources of thread until top exit frame.
static void Unwind(ThreadState* thread) { UnwindAbove(thread, nullptr); }
// Destroy stack resources of thread above new_top, exclusive.
static void UnwindAbove(ThreadState* thread, StackResource* new_top);
private:
void Init(ThreadState* thread);
ThreadState* thread_;
StackResource* previous_;
DISALLOW_ALLOCATION();
DISALLOW_IMPLICIT_CONSTRUCTORS(StackResource);
};
// 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 {
public:
ZoneAllocated() {}
// Implicitly allocate the object in the current zone.
void* operator new(size_t size);
// Allocate the object in the given zone, which must be the current zone.
void* operator new(size_t 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(); }
private:
DISALLOW_COPY_AND_ASSIGN(ZoneAllocated);
};
} // namespace dart
// Prevent use of `new (zone) DoesNotExtendZoneAllocated()`, which places the
// DoesNotExtendZoneAllocated on top of the Zone.
void* operator new(size_t size, dart::Zone* zone) = delete;
#endif // RUNTIME_VM_ALLOCATION_H_