1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/lock_impl.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,77 @@
1.4 +// Copyright (c) 2006-2008 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_IMPL_H_
1.9 +#define BASE_LOCK_IMPL_H_
1.10 +
1.11 +#include "build/build_config.h"
1.12 +
1.13 +#if defined(OS_WIN)
1.14 +#include <windows.h>
1.15 +#elif defined(OS_POSIX)
1.16 +#include <pthread.h>
1.17 +#endif
1.18 +
1.19 +#include "base/basictypes.h"
1.20 +#include "base/platform_thread.h"
1.21 +
1.22 +// This class implements the underlying platform-specific spin-lock mechanism
1.23 +// used for the Lock class. Most users should not use LockImpl directly, but
1.24 +// should instead use Lock.
1.25 +class LockImpl {
1.26 + public:
1.27 +#if defined(OS_WIN)
1.28 + typedef CRITICAL_SECTION OSLockType;
1.29 +#elif defined(OS_POSIX)
1.30 + typedef pthread_mutex_t OSLockType;
1.31 +#endif
1.32 +
1.33 + LockImpl();
1.34 + ~LockImpl();
1.35 +
1.36 + // If the lock is not held, take it and return true. If the lock is already
1.37 + // held by something else, immediately return false.
1.38 + bool Try();
1.39 +
1.40 + // Take the lock, blocking until it is available if necessary.
1.41 + void Lock();
1.42 +
1.43 + // Release the lock. This must only be called by the lock's holder: after
1.44 + // a successful call to Try, or a call to Lock.
1.45 + void Unlock();
1.46 +
1.47 + // Debug-only method that will DCHECK() if the lock is not acquired by the
1.48 + // current thread. In non-debug builds, no check is performed.
1.49 + // Because linux and mac condition variables modify the underlyning lock
1.50 + // through the os_lock() method, runtime assertions can not be done on those
1.51 + // builds.
1.52 +#if defined(NDEBUG) || !defined(OS_WIN)
1.53 + void AssertAcquired() const {}
1.54 +#else
1.55 + void AssertAcquired() const;
1.56 +#endif
1.57 +
1.58 + // Return the native underlying lock. Not supported for Windows builds.
1.59 + // TODO(awalker): refactor lock and condition variables so that this is
1.60 + // unnecessary.
1.61 +#if !defined(OS_WIN)
1.62 + OSLockType* os_lock() { return &os_lock_; }
1.63 +#endif
1.64 +
1.65 + private:
1.66 + OSLockType os_lock_;
1.67 +
1.68 +#if !defined(NDEBUG) && defined(OS_WIN)
1.69 + // All private data is implicitly protected by lock_.
1.70 + // Be VERY careful to only access members under that lock.
1.71 + PlatformThreadId owning_thread_id_;
1.72 + int32_t recursion_count_shadow_;
1.73 + bool recursion_used_; // Allow debugging to continued after a DCHECK().
1.74 +#endif // NDEBUG
1.75 +
1.76 + DISALLOW_COPY_AND_ASSIGN(LockImpl);
1.77 +};
1.78 +
1.79 +
1.80 +#endif // BASE_LOCK_IMPL_H_
