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      1 /*
      2  * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved.
      3  * Copyright (C) 2007 Justin Haygood (jhaygood (at) reaktix.com)
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * 1.  Redistributions of source code must retain the above copyright
     10  *     notice, this list of conditions and the following disclaimer.
     11  * 2.  Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     15  *     its contributors may be used to endorse or promote products derived
     16  *     from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28  *
     29  */
     30 
     31 #ifndef ThreadingPrimitives_h
     32 #define ThreadingPrimitives_h
     33 
     34 #include "wtf/Assertions.h"
     35 #include "wtf/FastAllocBase.h"
     36 #include "wtf/Locker.h"
     37 #include "wtf/Noncopyable.h"
     38 #include "wtf/WTFExport.h"
     39 
     40 #if OS(WIN)
     41 #include <windows.h>
     42 #endif
     43 
     44 #if USE(PTHREADS)
     45 #include <pthread.h>
     46 #endif
     47 
     48 namespace WTF {
     49 
     50 #if USE(PTHREADS)
     51 typedef pthread_mutex_t PlatformMutex;
     52 typedef pthread_cond_t PlatformCondition;
     53 #elif OS(WIN)
     54 struct PlatformMutex {
     55     CRITICAL_SECTION m_internalMutex;
     56     size_t m_recursionCount;
     57 };
     58 struct PlatformCondition {
     59     size_t m_waitersGone;
     60     size_t m_waitersBlocked;
     61     size_t m_waitersToUnblock;
     62     HANDLE m_blockLock;
     63     HANDLE m_blockQueue;
     64     HANDLE m_unblockLock;
     65 
     66     bool timedWait(PlatformMutex&, DWORD durationMilliseconds);
     67     void signal(bool unblockAll);
     68 };
     69 #else
     70 typedef void* PlatformMutex;
     71 typedef void* PlatformCondition;
     72 #endif
     73 
     74 class WTF_EXPORT Mutex {
     75     WTF_MAKE_NONCOPYABLE(Mutex); WTF_MAKE_FAST_ALLOCATED;
     76 public:
     77     Mutex();
     78     ~Mutex();
     79 
     80     void lock();
     81     bool tryLock();
     82     void unlock();
     83 
     84 public:
     85     PlatformMutex& impl() { return m_mutex; }
     86 private:
     87     PlatformMutex m_mutex;
     88 };
     89 
     90 typedef Locker<Mutex> MutexLocker;
     91 
     92 class MutexTryLocker {
     93     WTF_MAKE_NONCOPYABLE(MutexTryLocker);
     94 public:
     95     MutexTryLocker(Mutex& mutex) : m_mutex(mutex), m_locked(mutex.tryLock()) { }
     96     ~MutexTryLocker()
     97     {
     98         if (m_locked)
     99             m_mutex.unlock();
    100     }
    101 
    102     bool locked() const { return m_locked; }
    103 
    104 private:
    105     Mutex& m_mutex;
    106     bool m_locked;
    107 };
    108 
    109 class WTF_EXPORT ThreadCondition {
    110     WTF_MAKE_NONCOPYABLE(ThreadCondition);
    111 public:
    112     ThreadCondition();
    113     ~ThreadCondition();
    114 
    115     void wait(Mutex&);
    116     // Returns true if the condition was signaled before absoluteTime, false if the absoluteTime was reached or is in the past.
    117     // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
    118     bool timedWait(Mutex&, double absoluteTime);
    119     void signal();
    120     void broadcast();
    121 
    122 private:
    123     PlatformCondition m_condition;
    124 };
    125 
    126 #if OS(WIN)
    127 // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
    128 // Returns an interval in milliseconds suitable for passing to one of the Win32 wait functions (e.g., ::WaitForSingleObject).
    129 DWORD absoluteTimeToWaitTimeoutInterval(double absoluteTime);
    130 #endif
    131 
    132 } // namespace WTF
    133 
    134 using WTF::Mutex;
    135 using WTF::MutexLocker;
    136 using WTF::MutexTryLocker;
    137 using WTF::ThreadCondition;
    138 
    139 #if OS(WIN)
    140 using WTF::absoluteTimeToWaitTimeoutInterval;
    141 #endif
    142 
    143 #endif // ThreadingPrimitives_h
    144