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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 struct PlatformMutex {
     52     pthread_mutex_t m_internalMutex;
     53 #if ENABLE(ASSERT)
     54     size_t m_recursionCount;
     55 #endif
     56 };
     57 typedef pthread_cond_t PlatformCondition;
     58 #elif OS(WIN)
     59 struct PlatformMutex {
     60     CRITICAL_SECTION m_internalMutex;
     61     size_t m_recursionCount;
     62 };
     63 struct PlatformCondition {
     64     size_t m_waitersGone;
     65     size_t m_waitersBlocked;
     66     size_t m_waitersToUnblock;
     67     HANDLE m_blockLock;
     68     HANDLE m_blockQueue;
     69     HANDLE m_unblockLock;
     70 
     71     bool timedWait(PlatformMutex&, DWORD durationMilliseconds);
     72     void signal(bool unblockAll);
     73 };
     74 #else
     75 typedef void* PlatformMutex;
     76 typedef void* PlatformCondition;
     77 #endif
     78 
     79 class WTF_EXPORT MutexBase {
     80     WTF_MAKE_NONCOPYABLE(MutexBase); WTF_MAKE_FAST_ALLOCATED;
     81 public:
     82     ~MutexBase();
     83 
     84     void lock();
     85     void unlock();
     86 #if ENABLE(ASSERT)
     87     bool locked() { return m_mutex.m_recursionCount > 0; }
     88 #endif
     89 
     90 public:
     91     PlatformMutex& impl() { return m_mutex; }
     92 
     93 protected:
     94     MutexBase(bool recursive);
     95 
     96     PlatformMutex m_mutex;
     97 };
     98 
     99 class WTF_EXPORT Mutex : public MutexBase {
    100 public:
    101     Mutex() : MutexBase(false) { }
    102     bool tryLock();
    103 };
    104 
    105 class WTF_EXPORT RecursiveMutex : public MutexBase {
    106 public:
    107     RecursiveMutex() : MutexBase(true) { }
    108     bool tryLock();
    109 };
    110 
    111 typedef Locker<MutexBase> MutexLocker;
    112 
    113 class MutexTryLocker {
    114     WTF_MAKE_NONCOPYABLE(MutexTryLocker);
    115 public:
    116     MutexTryLocker(Mutex& mutex) : m_mutex(mutex), m_locked(mutex.tryLock()) { }
    117     ~MutexTryLocker()
    118     {
    119         if (m_locked)
    120             m_mutex.unlock();
    121     }
    122 
    123     bool locked() const { return m_locked; }
    124 
    125 private:
    126     Mutex& m_mutex;
    127     bool m_locked;
    128 };
    129 
    130 class WTF_EXPORT ThreadCondition {
    131     WTF_MAKE_NONCOPYABLE(ThreadCondition);
    132 public:
    133     ThreadCondition();
    134     ~ThreadCondition();
    135 
    136     void wait(MutexBase&);
    137     // Returns true if the condition was signaled before absoluteTime, false if the absoluteTime was reached or is in the past.
    138     // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
    139     bool timedWait(MutexBase&, double absoluteTime);
    140     void signal();
    141     void broadcast();
    142 
    143 private:
    144     PlatformCondition m_condition;
    145 };
    146 
    147 #if OS(WIN)
    148 // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
    149 // Returns an interval in milliseconds suitable for passing to one of the Win32 wait functions (e.g., ::WaitForSingleObject).
    150 DWORD absoluteTimeToWaitTimeoutInterval(double absoluteTime);
    151 #endif
    152 
    153 } // namespace WTF
    154 
    155 using WTF::MutexBase;
    156 using WTF::Mutex;
    157 using WTF::RecursiveMutex;
    158 using WTF::MutexLocker;
    159 using WTF::MutexTryLocker;
    160 using WTF::ThreadCondition;
    161 
    162 #if OS(WIN)
    163 using WTF::absoluteTimeToWaitTimeoutInterval;
    164 #endif
    165 
    166 #endif // ThreadingPrimitives_h
    167