wtf/Threading.h

   1 /*
   2  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
   3  * Copyright (C) 2007 Justin Haygood (jhaygood@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  * Note: The implementations of InterlockedIncrement and InterlockedDecrement are based
  31  * on atomic_increment and atomic_exchange_and_add from the Boost C++ Library. The license
  32  * is virtually identical to the Apple license above but is included here for completeness.
  33  *
  34  * Boost Software License - Version 1.0 - August 17th, 2003
  35  *
  36  * Permission is hereby granted, free of charge, to any person or organization
  37  * obtaining a copy of the software and accompanying documentation covered by
  38  * this license (the "Software") to use, reproduce, display, distribute,
  39  * execute, and transmit the Software, and to prepare derivative works of the
  40  * Software, and to permit third-parties to whom the Software is furnished to
  41  * do so, all subject to the following:
  42  *
  43  * The copyright notices in the Software and this entire statement, including
  44  * the above license grant, this restriction and the following disclaimer,
  45  * must be included in all copies of the Software, in whole or in part, and
  46  * all derivative works of the Software, unless such copies or derivative
  47  * works are solely in the form of machine-executable object code generated by
  48  * a source language processor.
  49  *
  50  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  51  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  52  * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  53  * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  54  * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  55  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  56  * DEALINGS IN THE SOFTWARE.
  57  */
  58
  59 #ifndef Threading_h
  60 #define Threading_h
  61
  62 #include <wtf/Platform.h>
  63
  64 #if PLATFORM(WIN_CE)
  65 #include <windows.h>
  66 #endif
  67
  68 #include <wtf/Assertions.h>
  69 #include <wtf/Locker.h>
  70 #include <wtf/Noncopyable.h>
  71
  72 #if PLATFORM(WIN_OS) && !PLATFORM(WIN_CE)
  73 #include <windows.h>
  74 #elif PLATFORM(DARWIN)
  75 #include <libkern/OSAtomic.h>
  76 #elif COMPILER(GCC)
  77 #if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 2))
  78 #include <ext/atomicity.h>
  79 #else
  80 #include <bits/atomicity.h>
  81 #endif
  82 #endif
  83
  84 #if USE(PTHREADS)
  85 #include <pthread.h>
  86 #elif PLATFORM(GTK)
  87 #include <wtf/GOwnPtr.h>
  88 typedef struct _GMutex GMutex;
  89 typedef struct _GCond GCond;
  90 #endif
  91
  92 #if USE(PTHREADS) && (PLATFORM(MAC) || PLATFORM(IPHONE))
  93 #ifdef __OBJC__
  94 @class NSThread;
  95 #else
  96 class NSThread;
  97 #endif
  98 #endif
  99
 100 #if PLATFORM(QT)
 101 #include <qglobal.h>
 102 QT_BEGIN_NAMESPACE
 103 class QMutex;
 104 class QWaitCondition;
 105 QT_END_NAMESPACE
 106 #endif
 107
 108 #include <stdint.h>
 109
 110 // For portability, we do not use thread-safe statics natively supported by some compilers (e.g. gcc).
 111 #define AtomicallyInitializedStatic(T, name) \
 112     WTF::lockAtomicallyInitializedStaticMutex(); \
 113     static T name; \
 114     WTF::unlockAtomicallyInitializedStaticMutex();
 115
 116 namespace WTF {
 117
 118 typedef uint32_t ThreadIdentifier;
 119 typedef void* (*ThreadFunction)(void* argument);
 120
 121 // Returns 0 if thread creation failed
 122 ThreadIdentifier createThread(ThreadFunction, void*, const char* threadName);
 123 ThreadIdentifier createThreadInternal(ThreadFunction, void*, const char* threadName);
 124
 125 ThreadIdentifier currentThread();
 126 bool isMainThread();
 127 int waitForThreadCompletion(ThreadIdentifier, void**);
 128 void detachThread(ThreadIdentifier);
 129
 130 #if USE(PTHREADS)
 131 typedef pthread_mutex_t PlatformMutex;
 132 typedef pthread_cond_t PlatformCondition;
 133 #elif PLATFORM(GTK)
 134 typedef GOwnPtr<GMutex> PlatformMutex;
 135 typedef GOwnPtr<GCond> PlatformCondition;
 136 #elif PLATFORM(QT)
 137 typedef QT_PREPEND_NAMESPACE(QMutex)* PlatformMutex;
 138 typedef QT_PREPEND_NAMESPACE(QWaitCondition)* PlatformCondition;
 139 #elif PLATFORM(WIN_OS)
 140 struct PlatformMutex {
 141     CRITICAL_SECTION m_internalMutex;
 142     size_t m_recursionCount;
 143 };
 144 struct PlatformCondition {
 145     size_t m_waitersGone;
 146     size_t m_waitersBlocked;
 147     size_t m_waitersToUnblock;
 148     HANDLE m_blockLock;
 149     HANDLE m_blockQueue;
 150     HANDLE m_unblockLock;
 151
 152     bool timedWait(PlatformMutex&, DWORD durationMilliseconds);
 153     void signal(bool unblockAll);
 154 };
 155 #else
 156 typedef void* PlatformMutex;
 157 typedef void* PlatformCondition;
 158 #endif
 159
 160 class Mutex : Noncopyable {
 161 public:
 162     Mutex();
 163     ~Mutex();
 164
 165     void lock();
 166     bool tryLock();
 167     void unlock();
 168
 169 public:
 170     PlatformMutex& impl() { return m_mutex; }
 171 private:
 172     PlatformMutex m_mutex;
 173 };
 174
 175 typedef Locker<Mutex> MutexLocker;
 176
 177 class ThreadCondition : Noncopyable {
 178 public:
 179     ThreadCondition();
 180     ~ThreadCondition();
 181
 182     void wait(Mutex& mutex);
 183     // Returns true if the condition was signaled before absoluteTime, false if the absoluteTime was reached or is in the past.
 184     // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
 185     bool timedWait(Mutex&, double absoluteTime);
 186     void signal();
 187     void broadcast();
 188
 189 private:
 190     PlatformCondition m_condition;
 191 };
 192
 193 #if PLATFORM(WIN_OS)
 194 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 195
 196 #if COMPILER(MINGW) || COMPILER(MSVC7) || PLATFORM(WIN_CE)
 197 inline void atomicIncrement(int* addend) { InterlockedIncrement(reinterpret_cast<long*>(addend)); }
 198 inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
 199 #else
 200 inline void atomicIncrement(int volatile* addend) { InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); }
 201 inline int atomicDecrement(int volatile* addend) { return InterlockedDecrement(reinterpret_cast<long volatile*>(addend)); }
 202 #endif
 203
 204 #elif PLATFORM(DARWIN)
 205 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 206
 207 inline void atomicIncrement(int volatile* addend) { OSAtomicIncrement32Barrier(const_cast<int*>(addend)); }
 208 inline int atomicDecrement(int volatile* addend) { return OSAtomicDecrement32Barrier(const_cast<int*>(addend)); }
 209
 210 #elif COMPILER(GCC)
 211 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 212
 213 inline void atomicIncrement(int volatile* addend) { __gnu_cxx::__atomic_add(addend, 1); }
 214 inline int atomicDecrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, -1) - 1; }
 215
 216 #endif
 217
 218 template<class T> class ThreadSafeShared : Noncopyable {
 219 public:
 220     ThreadSafeShared(int initialRefCount = 1)
 221         : m_refCount(initialRefCount)
 222     {
 223     }
 224
 225     void ref()
 226     {
 227 #if USE(LOCKFREE_THREADSAFESHARED)
 228         atomicIncrement(&m_refCount);
 229 #else
 230         MutexLocker locker(m_mutex);
 231         ++m_refCount;
 232 #endif
 233     }
 234
 235     void deref()
 236     {
 237 #if USE(LOCKFREE_THREADSAFESHARED)
 238         if (atomicDecrement(&m_refCount) <= 0)
 239 #else
 240         {
 241             MutexLocker locker(m_mutex);
 242             --m_refCount;
 243         }
 244         if (m_refCount <= 0)
 245 #endif
 246             delete static_cast<T*>(this);
 247     }
 248
 249     bool hasOneRef()
 250     {
 251         return refCount() == 1;
 252     }
 253
 254     int refCount() const
 255     {
 256 #if !USE(LOCKFREE_THREADSAFESHARED)
 257         MutexLocker locker(m_mutex);
 258 #endif
 259         return static_cast<int const volatile &>(m_refCount);
 260     }
 261
 262 private:
 263     int m_refCount;
 264 #if !USE(LOCKFREE_THREADSAFESHARED)
 265     mutable Mutex m_mutex;
 266 #endif
 267 };
 268
 269 // This function must be called from the main thread. It is safe to call it repeatedly.
 270 // Darwin is an exception to this rule: it is OK to call it from any thread, the only requirement is that the calls are not reentrant.
 271 void initializeThreading();
 272
 273 #if USE(PTHREADS) && (PLATFORM(MAC) || PLATFORM(IPHONE))
 274 void initializeMainNSThread();
 275 NSThread *mainNSThread();
 276 #endif
 277
 278 void lockAtomicallyInitializedStaticMutex();
 279 void unlockAtomicallyInitializedStaticMutex();
 280
 281 } // namespace WTF
 282
 283 using WTF::Mutex;
 284 using WTF::MutexLocker;
 285 using WTF::ThreadCondition;
 286 using WTF::ThreadIdentifier;
 287 using WTF::ThreadSafeShared;
 288
 289 using WTF::createThread;
 290 using WTF::currentThread;
 291 using WTF::isMainThread;
 292 using WTF::detachThread;
 293 using WTF::waitForThreadCompletion;
 294
 295 #endif // Threading_h