| // 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 <mutex> |
| |
| #ifdef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP |
| |
| #include <windows.h> |
| |
| // GetMessage conflicts with GeneratedMessageReflection::GetMessage(). |
| #ifdef GetMessage |
| #undef GetMessage |
| #endif |
| |
| #endif |
| |
| #include <google/protobuf/stubs/macros.h> |
| |
| // Define thread-safety annotations for use below, if we are building with |
| // Clang. |
| #if defined(__clang__) && !defined(SWIG) |
| #define GOOGLE_PROTOBUF_ACQUIRE(...) \ |
| __attribute__((acquire_capability(__VA_ARGS__))) |
| #define GOOGLE_PROTOBUF_RELEASE(...) \ |
| __attribute__((release_capability(__VA_ARGS__))) |
| #define GOOGLE_PROTOBUF_SCOPED_CAPABILITY __attribute__((scoped_lockable)) |
| #define GOOGLE_PROTOBUF_CAPABILITY(x) __attribute__((capability(x))) |
| #else |
| #define GOOGLE_PROTOBUF_ACQUIRE(...) |
| #define GOOGLE_PROTOBUF_RELEASE(...) |
| #define GOOGLE_PROTOBUF_SCOPED_CAPABILITY |
| #define GOOGLE_PROTOBUF_CAPABILITY(x) |
| #endif |
| |
| #include <google/protobuf/port_def.inc> |
| |
| // =================================================================== |
| // emulates google3/base/mutex.h |
| namespace google { |
| namespace protobuf { |
| namespace internal { |
| |
| #define GOOGLE_PROTOBUF_LINKER_INITIALIZED |
| |
| #ifdef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP |
| |
| // This class is a lightweight replacement for std::mutex on Windows platforms. |
| // std::mutex does not work on Windows XP SP2 with the latest VC++ libraries, |
| // because it utilizes the Concurrency Runtime that is only supported on Windows |
| // XP SP3 and above. |
| class PROTOBUF_EXPORT CriticalSectionLock { |
| public: |
| CriticalSectionLock() { InitializeCriticalSection(&critical_section_); } |
| ~CriticalSectionLock() { DeleteCriticalSection(&critical_section_); } |
| void lock() { EnterCriticalSection(&critical_section_); } |
| void unlock() { LeaveCriticalSection(&critical_section_); } |
| |
| private: |
| CRITICAL_SECTION critical_section_; |
| |
| GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CriticalSectionLock); |
| }; |
| |
| #endif |
| |
| // In MSVC std::mutex does not have a constexpr constructor. |
| // This wrapper makes the constructor constexpr. |
| template <typename T> |
| class CallOnceInitializedMutex { |
| public: |
| constexpr CallOnceInitializedMutex() : flag_{}, buf_{} {} |
| ~CallOnceInitializedMutex() { get().~T(); } |
| |
| void lock() { get().lock(); } |
| void unlock() { get().unlock(); } |
| |
| private: |
| T& get() { |
| std::call_once(flag_, [&] { ::new (static_cast<void*>(&buf_)) T(); }); |
| return reinterpret_cast<T&>(buf_); |
| } |
| |
| std::once_flag flag_; |
| alignas(T) char buf_[sizeof(T)]; |
| }; |
| |
| // Mutex is a natural type to wrap. As both google and other organization have |
| // specialized mutexes. gRPC also provides an injection mechanism for custom |
| // mutexes. |
| class GOOGLE_PROTOBUF_CAPABILITY("mutex") PROTOBUF_EXPORT WrappedMutex { |
| public: |
| #if defined(__QNX__) |
| constexpr WrappedMutex() = default; |
| #else |
| constexpr WrappedMutex() {} |
| #endif |
| void Lock() GOOGLE_PROTOBUF_ACQUIRE() { mu_.lock(); } |
| void Unlock() GOOGLE_PROTOBUF_RELEASE() { mu_.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() const {} |
| |
| private: |
| #if defined(GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP) |
| CallOnceInitializedMutex<CriticalSectionLock> mu_{}; |
| #elif defined(_WIN32) |
| CallOnceInitializedMutex<std::mutex> mu_{}; |
| #else |
| std::mutex mu_{}; |
| #endif |
| }; |
| |
| using Mutex = WrappedMutex; |
| |
| // MutexLock(mu) acquires mu when constructed and releases it when destroyed. |
| class GOOGLE_PROTOBUF_SCOPED_CAPABILITY PROTOBUF_EXPORT MutexLock { |
| public: |
| explicit MutexLock(Mutex *mu) GOOGLE_PROTOBUF_ACQUIRE(mu) : mu_(mu) { |
| this->mu_->Lock(); |
| } |
| ~MutexLock() GOOGLE_PROTOBUF_RELEASE() { 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 nullptr. |
| class PROTOBUF_EXPORT MutexLockMaybe { |
| public: |
| explicit MutexLockMaybe(Mutex *mu) : |
| mu_(mu) { if (this->mu_ != nullptr) { this->mu_->Lock(); } } |
| ~MutexLockMaybe() { if (this->mu_ != nullptr) { 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 == nullptr) { |
| 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 |
| |
| #undef GOOGLE_PROTOBUF_ACQUIRE |
| #undef GOOGLE_PROTOBUF_RELEASE |
| |
| #include <google/protobuf/port_undef.inc> |
| |
| #endif // GOOGLE_PROTOBUF_STUBS_MUTEX_H_ |