1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/lock.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,75 @@
1.4 +// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#ifndef BASE_LOCK_H_
1.9 +#define BASE_LOCK_H_
1.10 +
1.11 +#include "base/lock_impl.h"
1.12 +
1.13 +// A convenient wrapper for an OS specific critical section.
1.14 +
1.15 +class Lock {
1.16 + public:
1.17 + Lock() : lock_() {}
1.18 + ~Lock() {}
1.19 + void Acquire() { lock_.Lock(); }
1.20 + void Release() { lock_.Unlock(); }
1.21 + // If the lock is not held, take it and return true. If the lock is already
1.22 + // held by another thread, immediately return false.
1.23 + bool Try() { return lock_.Try(); }
1.24 +
1.25 + // In debug builds this method checks that the lock has been acquired by the
1.26 + // calling thread. If the lock has not been acquired, then the method
1.27 + // will DCHECK(). In non-debug builds, the LockImpl's implementation of
1.28 + // AssertAcquired() is an empty inline method.
1.29 + void AssertAcquired() const { return lock_.AssertAcquired(); }
1.30 +
1.31 + // Return the underlying lock implementation.
1.32 + // TODO(awalker): refactor lock and condition variables so that this is
1.33 + // unnecessary.
1.34 + LockImpl* lock_impl() { return &lock_; }
1.35 +
1.36 + private:
1.37 + LockImpl lock_; // Platform specific underlying lock implementation.
1.38 +
1.39 + DISALLOW_COPY_AND_ASSIGN(Lock);
1.40 +};
1.41 +
1.42 +// A helper class that acquires the given Lock while the AutoLock is in scope.
1.43 +class AutoLock {
1.44 + public:
1.45 + explicit AutoLock(Lock& lock) : lock_(lock) {
1.46 + lock_.Acquire();
1.47 + }
1.48 +
1.49 + ~AutoLock() {
1.50 + lock_.AssertAcquired();
1.51 + lock_.Release();
1.52 + }
1.53 +
1.54 + private:
1.55 + Lock& lock_;
1.56 + DISALLOW_COPY_AND_ASSIGN(AutoLock);
1.57 +};
1.58 +
1.59 +// AutoUnlock is a helper that will Release() the |lock| argument in the
1.60 +// constructor, and re-Acquire() it in the destructor.
1.61 +class AutoUnlock {
1.62 + public:
1.63 + explicit AutoUnlock(Lock& lock) : lock_(lock) {
1.64 + // We require our caller to have the lock.
1.65 + lock_.AssertAcquired();
1.66 + lock_.Release();
1.67 + }
1.68 +
1.69 + ~AutoUnlock() {
1.70 + lock_.Acquire();
1.71 + }
1.72 +
1.73 + private:
1.74 + Lock& lock_;
1.75 + DISALLOW_COPY_AND_ASSIGN(AutoUnlock);
1.76 +};
1.77 +
1.78 +#endif // BASE_LOCK_H_
