| /* |
| * libjingle |
| * Copyright 2004, Google Inc. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. 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. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 TALK_BASE_CRITICALSECTION_H__ |
| #define TALK_BASE_CRITICALSECTION_H__ |
| |
| #include "talk/base/constructormagic.h" |
| |
| #ifdef WIN32 |
| #include "talk/base/win32.h" |
| #endif |
| |
| #ifdef POSIX |
| #include <pthread.h> |
| #endif |
| |
| #ifdef _DEBUG |
| #define CS_TRACK_OWNER 1 |
| #endif // _DEBUG |
| |
| #if CS_TRACK_OWNER |
| #define TRACK_OWNER(x) x |
| #else // !CS_TRACK_OWNER |
| #define TRACK_OWNER(x) |
| #endif // !CS_TRACK_OWNER |
| |
| namespace talk_base { |
| |
| #ifdef WIN32 |
| class CriticalSection { |
| public: |
| CriticalSection() { |
| InitializeCriticalSection(&crit_); |
| // Windows docs say 0 is not a valid thread id |
| TRACK_OWNER(thread_ = 0); |
| } |
| ~CriticalSection() { |
| DeleteCriticalSection(&crit_); |
| } |
| void Enter() { |
| EnterCriticalSection(&crit_); |
| TRACK_OWNER(thread_ = GetCurrentThreadId()); |
| } |
| bool TryEnter() { |
| if (TryEnterCriticalSection(&crit_) != FALSE) { |
| TRACK_OWNER(thread_ = GetCurrentThreadId()); |
| return true; |
| } |
| return false; |
| } |
| void Leave() { |
| TRACK_OWNER(thread_ = 0); |
| LeaveCriticalSection(&crit_); |
| } |
| |
| #if CS_TRACK_OWNER |
| bool CurrentThreadIsOwner() const { return thread_ == GetCurrentThreadId(); } |
| #endif // CS_TRACK_OWNER |
| |
| private: |
| CRITICAL_SECTION crit_; |
| TRACK_OWNER(DWORD thread_); // The section's owning thread id |
| }; |
| #endif // WIN32 |
| |
| #ifdef POSIX |
| class CriticalSection { |
| public: |
| CriticalSection() { |
| pthread_mutexattr_t mutex_attribute; |
| pthread_mutexattr_init(&mutex_attribute); |
| pthread_mutexattr_settype(&mutex_attribute, PTHREAD_MUTEX_RECURSIVE); |
| pthread_mutex_init(&mutex_, &mutex_attribute); |
| pthread_mutexattr_destroy(&mutex_attribute); |
| TRACK_OWNER(thread_ = 0); |
| } |
| ~CriticalSection() { |
| pthread_mutex_destroy(&mutex_); |
| } |
| void Enter() { |
| pthread_mutex_lock(&mutex_); |
| TRACK_OWNER(thread_ = pthread_self()); |
| } |
| bool TryEnter() { |
| if (pthread_mutex_trylock(&mutex_) == 0) { |
| TRACK_OWNER(thread_ = pthread_self()); |
| return true; |
| } |
| return false; |
| } |
| void Leave() { |
| TRACK_OWNER(thread_ = 0); |
| pthread_mutex_unlock(&mutex_); |
| } |
| |
| #if CS_TRACK_OWNER |
| bool CurrentThreadIsOwner() const { return pthread_equal(thread_, pthread_self()); } |
| #endif // CS_TRACK_OWNER |
| |
| private: |
| pthread_mutex_t mutex_; |
| TRACK_OWNER(pthread_t thread_); |
| }; |
| #endif // POSIX |
| |
| // CritScope, for serializing execution through a scope. |
| class CritScope { |
| public: |
| explicit CritScope(CriticalSection *pcrit) { |
| pcrit_ = pcrit; |
| pcrit_->Enter(); |
| } |
| ~CritScope() { |
| pcrit_->Leave(); |
| } |
| private: |
| CriticalSection *pcrit_; |
| DISALLOW_COPY_AND_ASSIGN(CritScope); |
| }; |
| |
| // Tries to lock a critical section on construction via |
| // CriticalSection::TryEnter, and unlocks on destruction if the |
| // lock was taken. Never blocks. |
| // |
| // IMPORTANT: Unlike CritScope, the lock may not be owned by this thread in |
| // subsequent code. Users *must* check locked() to determine if the |
| // lock was taken. If you're not calling locked(), you're doing it wrong! |
| class TryCritScope { |
| public: |
| explicit TryCritScope(CriticalSection *pcrit) { |
| pcrit_ = pcrit; |
| locked_ = pcrit_->TryEnter(); |
| } |
| ~TryCritScope() { |
| if (locked_) { |
| pcrit_->Leave(); |
| } |
| } |
| bool locked() const { |
| return locked_; |
| } |
| private: |
| CriticalSection *pcrit_; |
| bool locked_; |
| DISALLOW_COPY_AND_ASSIGN(TryCritScope); |
| }; |
| |
| // TODO: Move this to atomicops.h, which can't be done easily because of |
| // complex compile rules. |
| class AtomicOps { |
| public: |
| #ifdef WIN32 |
| // Assumes sizeof(int) == sizeof(LONG), which it is on Win32 and Win64. |
| static int Increment(int* i) { |
| return ::InterlockedIncrement(reinterpret_cast<LONG*>(i)); |
| } |
| static int Decrement(int* i) { |
| return ::InterlockedDecrement(reinterpret_cast<LONG*>(i)); |
| } |
| #else |
| static int Increment(int* i) { |
| return __sync_add_and_fetch(i, 1); |
| } |
| static int Decrement(int* i) { |
| return __sync_sub_and_fetch(i, 1); |
| } |
| #endif |
| }; |
| |
| } // namespace talk_base |
| |
| #endif // TALK_BASE_CRITICALSECTION_H__ |