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author | Jisi Liu <jisi.liu@gmail.com> | 2015-07-16 16:49:38 -0700 |
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committer | Jisi Liu <jisi.liu@gmail.com> | 2015-07-16 16:49:38 -0700 |
commit | 4e694f7b23c3cdfacf5ba5991e986c93b49997e9 (patch) | |
tree | 52908d9081696b9e507e9d3276212e609d45c718 /src/google/protobuf/stubs/mutex.h | |
parent | fde6e89f99eda04a4f1b8677bcea07e6c2040405 (diff) | |
download | protobuf-4e694f7b23c3cdfacf5ba5991e986c93b49997e9.tar.gz protobuf-4e694f7b23c3cdfacf5ba5991e986c93b49997e9.tar.bz2 protobuf-4e694f7b23c3cdfacf5ba5991e986c93b49997e9.zip |
Split up common.h headers
Change-Id: I223783111d743aa5193bf70fa1b9b54c7b4389c3
Diffstat (limited to 'src/google/protobuf/stubs/mutex.h')
-rw-r--r-- | src/google/protobuf/stubs/mutex.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/src/google/protobuf/stubs/mutex.h b/src/google/protobuf/stubs/mutex.h new file mode 100644 index 00000000..2cce0561 --- /dev/null +++ b/src/google/protobuf/stubs/mutex.h @@ -0,0 +1,144 @@ +// Copyright (c) 2006, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef GOOGLE_PROTOBUF_STUBS_MUTEX_H_ +#define GOOGLE_PROTOBUF_STUBS_MUTEX_H_ + +#include <google/protobuf/stubs/macros.h> + +// =================================================================== +// emulates google3/base/mutex.h +namespace google { +namespace protobuf { +namespace internal { + +// A Mutex is a non-reentrant (aka non-recursive) mutex. At most one thread T +// may hold a mutex at a given time. If T attempts to Lock() the same Mutex +// while holding it, T will deadlock. +class LIBPROTOBUF_EXPORT Mutex { + public: + // Create a Mutex that is not held by anybody. + Mutex(); + + // Destructor + ~Mutex(); + + // Block if necessary until this Mutex is free, then acquire it exclusively. + void Lock(); + + // Release this Mutex. Caller must hold it exclusively. + void Unlock(); + + // Crash if this Mutex is not held exclusively by this thread. + // May fail to crash when it should; will never crash when it should not. + void AssertHeld(); + + private: + struct Internal; + Internal* mInternal; + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Mutex); +}; + +// Undefine the macros to workaround the conflicts with Google internal +// MutexLock implementation. +// TODO(liujisi): Remove the undef once internal macros are removed. +#undef MutexLock +#undef ReaderMutexLock +#undef WriterMutexLock +#undef MutexLockMaybe + +// MutexLock(mu) acquires mu when constructed and releases it when destroyed. +class LIBPROTOBUF_EXPORT MutexLock { + public: + explicit MutexLock(Mutex *mu) : mu_(mu) { this->mu_->Lock(); } + ~MutexLock() { this->mu_->Unlock(); } + private: + Mutex *const mu_; + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MutexLock); +}; + +// TODO(kenton): Implement these? Hard to implement portably. +typedef MutexLock ReaderMutexLock; +typedef MutexLock WriterMutexLock; + +// MutexLockMaybe is like MutexLock, but is a no-op when mu is NULL. +class LIBPROTOBUF_EXPORT MutexLockMaybe { + public: + explicit MutexLockMaybe(Mutex *mu) : + mu_(mu) { if (this->mu_ != NULL) { this->mu_->Lock(); } } + ~MutexLockMaybe() { if (this->mu_ != NULL) { this->mu_->Unlock(); } } + private: + Mutex *const mu_; + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MutexLockMaybe); +}; + +#if defined(GOOGLE_PROTOBUF_NO_THREADLOCAL) +template<typename T> +class ThreadLocalStorage { + public: + ThreadLocalStorage() { + pthread_key_create(&key_, &ThreadLocalStorage::Delete); + } + ~ThreadLocalStorage() { + pthread_key_delete(key_); + } + T* Get() { + T* result = static_cast<T*>(pthread_getspecific(key_)); + if (result == NULL) { + result = new T(); + pthread_setspecific(key_, result); + } + return result; + } + private: + static void Delete(void* value) { + delete static_cast<T*>(value); + } + pthread_key_t key_; + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ThreadLocalStorage); +}; +#endif + +} // namespace internal + +// We made these internal so that they would show up as such in the docs, +// but we don't want to stick "internal::" in front of them everywhere. +using internal::Mutex; +using internal::MutexLock; +using internal::ReaderMutexLock; +using internal::WriterMutexLock; +using internal::MutexLockMaybe; + + +} // namespace protobuf +} // namespace google + +#endif // GOOGLE_PROTOBUF_STUBS_MUTEX_H_ |