mirror of
https://github.com/klzgrad/naiveproxy.git
synced 2024-12-01 01:36:09 +03:00
89 lines
2.9 KiB
C++
89 lines
2.9 KiB
C++
// Copyright (c) 2012 The Chromium 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 BASE_SEQUENCE_CHECKER_H_
|
|
#define BASE_SEQUENCE_CHECKER_H_
|
|
|
|
#include "base/compiler_specific.h"
|
|
#include "base/logging.h"
|
|
#include "base/sequence_checker_impl.h"
|
|
|
|
// SequenceChecker is a helper class used to help verify that some methods of a
|
|
// class are called sequentially (for thread-safety).
|
|
//
|
|
// Use the macros below instead of the SequenceChecker directly so that the
|
|
// unused member doesn't result in an extra byte (four when padded) per
|
|
// instance in production.
|
|
//
|
|
// This class is much prefered to ThreadChecker for thread-safety checks.
|
|
// ThreadChecker should only be used for classes that are truly thread-affine
|
|
// (use thread-local-storage or a third-party API that does).
|
|
//
|
|
// Usage:
|
|
// class MyClass {
|
|
// public:
|
|
// MyClass() {
|
|
// // It's sometimes useful to detach on construction for objects that are
|
|
// // constructed in one place and forever after used from another
|
|
// // sequence.
|
|
// DETACH_FROM_SEQUENCE(my_sequence_checker_);
|
|
// }
|
|
//
|
|
// ~MyClass() {
|
|
// // SequenceChecker doesn't automatically check it's destroyed on origin
|
|
// // sequence for the same reason it's sometimes detached in the
|
|
// // constructor. It's okay to destroy off sequence if the owner
|
|
// // otherwise knows usage on the associated sequence is done. If you're
|
|
// // not detaching in the constructor, you probably want to explicitly
|
|
// // check in the destructor.
|
|
// DCHECK_CALLED_ON_VALID_SEQUENCE(my_sequence_checker_);
|
|
// }
|
|
// void MyMethod() {
|
|
// DCHECK_CALLED_ON_VALID_SEQUENCE(my_sequence_checker_);
|
|
// ... (do stuff) ...
|
|
// }
|
|
//
|
|
// private:
|
|
// SEQUENCE_CHECKER(my_sequence_checker_);
|
|
// }
|
|
|
|
#if DCHECK_IS_ON()
|
|
#define SEQUENCE_CHECKER(name) base::SequenceChecker name
|
|
#define DCHECK_CALLED_ON_VALID_SEQUENCE(name) \
|
|
DCHECK((name).CalledOnValidSequence())
|
|
#define DETACH_FROM_SEQUENCE(name) (name).DetachFromSequence()
|
|
#else // DCHECK_IS_ON()
|
|
#define SEQUENCE_CHECKER(name)
|
|
#define DCHECK_CALLED_ON_VALID_SEQUENCE(name) EAT_STREAM_PARAMETERS
|
|
#define DETACH_FROM_SEQUENCE(name)
|
|
#endif // DCHECK_IS_ON()
|
|
|
|
namespace base {
|
|
|
|
// Do nothing implementation, for use in release mode.
|
|
//
|
|
// Note: You should almost always use the SequenceChecker class (through the
|
|
// above macros) to get the right version for your build configuration.
|
|
class SequenceCheckerDoNothing {
|
|
public:
|
|
SequenceCheckerDoNothing() = default;
|
|
bool CalledOnValidSequence() const WARN_UNUSED_RESULT { return true; }
|
|
void DetachFromSequence() {}
|
|
|
|
private:
|
|
DISALLOW_COPY_AND_ASSIGN(SequenceCheckerDoNothing);
|
|
};
|
|
|
|
#if DCHECK_IS_ON()
|
|
class SequenceChecker : public SequenceCheckerImpl {
|
|
};
|
|
#else
|
|
class SequenceChecker : public SequenceCheckerDoNothing {
|
|
};
|
|
#endif // DCHECK_IS_ON()
|
|
|
|
} // namespace base
|
|
|
|
#endif // BASE_SEQUENCE_CHECKER_H_
|