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 "Platform.h"
  63
  64 #if OS(WINCE)
  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 OS(WINDOWS) && !OS(WINCE)
  73 #include <windows.h>
  74 #elif OS(DARWIN)
  75 #include <libkern/OSAtomic.h>
  76 #elif OS(ANDROID)
  77 #include <cutils/atomic.h>
  78 #elif COMPILER(GCC)
  79 #if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 2))
  80 #include <ext/atomicity.h>
  81 #else
  82 #include <bits/atomicity.h>
  83 #endif
  84 #endif
  85
  86 #if USE(PTHREADS)
  87 #include <pthread.h>
  88 #elif PLATFORM(GTK)
  89 #include <wtf/gtk/GOwnPtr.h>
  90 typedef struct _GMutex GMutex;
  91 typedef struct _GCond GCond;
  92 #endif
  93
  94 #if PLATFORM(QT)
  95 #include <qglobal.h>
  96 QT_BEGIN_NAMESPACE
  97 class QMutex;
  98 class QWaitCondition;
  99 QT_END_NAMESPACE
 100 #endif
 101
 102 #include <stdint.h>
 103
 104 // For portability, we do not use thread-safe statics natively supported by some compilers (e.g. gcc).
 105 #define AtomicallyInitializedStatic(T, name) \
 106     WTF::lockAtomicallyInitializedStaticMutex(); \
 107     static T name; \
 108     WTF::unlockAtomicallyInitializedStaticMutex();
 109
 110 namespace WTF {
 111
 112 typedef uint32_t ThreadIdentifier;
 113 typedef void* (*ThreadFunction)(void* argument);
 114
 115 // Returns 0 if thread creation failed.
 116 // The thread name must be a literal since on some platforms it's passed in to the thread.
 117 ThreadIdentifier createThread(ThreadFunction, void*, const char* threadName);
 118
 119 // Internal platform-specific createThread implementation.
 120 ThreadIdentifier createThreadInternal(ThreadFunction, void*, const char* threadName);
 121
 122 // Called in the thread during initialization.
 123 // Helpful for platforms where the thread name must be set from within the thread.
 124 void initializeCurrentThreadInternal(const char* threadName);
 125
 126 ThreadIdentifier currentThread();
 127 bool isMainThread();
 128 int waitForThreadCompletion(ThreadIdentifier, void**);
 129 void detachThread(ThreadIdentifier);
 130
 131 #if USE(PTHREADS)
 132 typedef pthread_mutex_t PlatformMutex;
 133 #if HAVE(PTHREAD_RWLOCK)
 134 typedef pthread_rwlock_t PlatformReadWriteLock;
 135 #else
 136 typedef void* PlatformReadWriteLock;
 137 #endif
 138 typedef pthread_cond_t PlatformCondition;
 139 #elif PLATFORM(GTK)
 140 typedef GOwnPtr<GMutex> PlatformMutex;
 141 typedef void* PlatformReadWriteLock; // FIXME: Implement.
 142 typedef GOwnPtr<GCond> PlatformCondition;
 143 #elif PLATFORM(QT)
 144 typedef QT_PREPEND_NAMESPACE(QMutex)* PlatformMutex;
 145 typedef void* PlatformReadWriteLock; // FIXME: Implement.
 146 typedef QT_PREPEND_NAMESPACE(QWaitCondition)* PlatformCondition;
 147 #elif OS(WINDOWS)
 148 struct PlatformMutex {
 149     CRITICAL_SECTION m_internalMutex;
 150     size_t m_recursionCount;
 151 };
 152 typedef void* PlatformReadWriteLock; // FIXME: Implement.
 153 struct PlatformCondition {
 154     size_t m_waitersGone;
 155     size_t m_waitersBlocked;
 156     size_t m_waitersToUnblock;
 157     HANDLE m_blockLock;
 158     HANDLE m_blockQueue;
 159     HANDLE m_unblockLock;
 160
 161     bool timedWait(PlatformMutex&, DWORD durationMilliseconds);
 162     void signal(bool unblockAll);
 163 };
 164 #else
 165 typedef void* PlatformMutex;
 166 typedef void* PlatformReadWriteLock;
 167 typedef void* PlatformCondition;
 168 #endif
 169
 170 class Mutex : public Noncopyable {
 171 public:
 172     Mutex();
 173     ~Mutex();
 174
 175     void lock();
 176     bool tryLock();
 177     void unlock();
 178
 179 public:
 180     PlatformMutex& impl() { return m_mutex; }
 181 private:
 182     PlatformMutex m_mutex;
 183 };
 184
 185 typedef Locker<Mutex> MutexLocker;
 186
 187 class ReadWriteLock : public Noncopyable {
 188 public:
 189     ReadWriteLock();
 190     ~ReadWriteLock();
 191
 192     void readLock();
 193     bool tryReadLock();
 194
 195     void writeLock();
 196     bool tryWriteLock();
 197
 198     void unlock();
 199
 200 private:
 201     PlatformReadWriteLock m_readWriteLock;
 202 };
 203
 204 class ThreadCondition : public Noncopyable {
 205 public:
 206     ThreadCondition();
 207     ~ThreadCondition();
 208
 209     void wait(Mutex& mutex);
 210     // Returns true if the condition was signaled before absoluteTime, false if the absoluteTime was reached or is in the past.
 211     // The absoluteTime is in seconds, starting on January 1, 1970. The time is assumed to use the same time zone as WTF::currentTime().
 212     bool timedWait(Mutex&, double absoluteTime);
 213     void signal();
 214     void broadcast();
 215
 216 private:
 217     PlatformCondition m_condition;
 218 };
 219
 220 #if OS(WINDOWS)
 221 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 222
 223 #if COMPILER(MINGW) || COMPILER(MSVC7) || OS(WINCE)
 224 inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); }
 225 inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
 226 #else
 227 inline int atomicIncrement(int volatile* addend) { return InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); }
 228 inline int atomicDecrement(int volatile* addend) { return InterlockedDecrement(reinterpret_cast<long volatile*>(addend)); }
 229 #endif
 230
 231 #elif OS(DARWIN)
 232 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 233
 234 inline int atomicIncrement(int volatile* addend) { return OSAtomicIncrement32Barrier(const_cast<int*>(addend)); }
 235 inline int atomicDecrement(int volatile* addend) { return OSAtomicDecrement32Barrier(const_cast<int*>(addend)); }
 236
 237 #elif OS(ANDROID)
 238
 239 inline int atomicIncrement(int volatile* addend) { return android_atomic_inc(addend); }
 240 inline int atomicDecrement(int volatile* addend) { return android_atomic_dec(addend); }
 241
 242 #elif COMPILER(GCC) && !CPU(SPARC64) // sizeof(_Atomic_word) != sizeof(int) on sparc64 gcc
 243 #define WTF_USE_LOCKFREE_THREADSAFESHARED 1
 244
 245 inline int atomicIncrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, 1) + 1; }
 246 inline int atomicDecrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, -1) - 1; }
 247
 248 #endif
 249
 250 class ThreadSafeSharedBase : public Noncopyable {
 251 public:
 252     ThreadSafeSharedBase(int initialRefCount = 1)
 253         : m_refCount(initialRefCount)
 254     {
 255     }
 256
 257     void ref()
 258     {
 259 #if USE(LOCKFREE_THREADSAFESHARED)
 260         atomicIncrement(&m_refCount);
 261 #else
 262         MutexLocker locker(m_mutex);
 263         ++m_refCount;
 264 #endif
 265     }
 266
 267     bool hasOneRef()
 268     {
 269         return refCount() == 1;
 270     }
 271
 272     int refCount() const
 273     {
 274 #if !USE(LOCKFREE_THREADSAFESHARED)
 275         MutexLocker locker(m_mutex);
 276 #endif
 277         return static_cast<int const volatile &>(m_refCount);
 278     }
 279
 280 protected:
 281     // Returns whether the pointer should be freed or not.
 282     bool derefBase()
 283     {
 284 #if USE(LOCKFREE_THREADSAFESHARED)
 285         if (atomicDecrement(&m_refCount) <= 0)
 286             return true;
 287 #else
 288         int refCount;
 289         {
 290             MutexLocker locker(m_mutex);
 291             --m_refCount;
 292             refCount = m_refCount;
 293         }
 294         if (refCount <= 0)
 295             return true;
 296 #endif
 297         return false;
 298     }
 299
 300 private:
 301     template<class T>
 302     friend class CrossThreadRefCounted;
 303
 304     int m_refCount;
 305 #if !USE(LOCKFREE_THREADSAFESHARED)
 306     mutable Mutex m_mutex;
 307 #endif
 308 };
 309
 310 template<class T> class ThreadSafeShared : public ThreadSafeSharedBase {
 311 public:
 312     ThreadSafeShared(int initialRefCount = 1)
 313         : ThreadSafeSharedBase(initialRefCount)
 314     {
 315     }
 316
 317     void deref()
 318     {
 319         if (derefBase())
 320             delete static_cast<T*>(this);
 321     }
 322 };
 323
 324 // This function must be called from the main thread. It is safe to call it repeatedly.
 325 // 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.
 326 void initializeThreading();
 327
 328 void lockAtomicallyInitializedStaticMutex();
 329 void unlockAtomicallyInitializedStaticMutex();
 330
 331 } // namespace WTF
 332
 333 using WTF::Mutex;
 334 using WTF::MutexLocker;
 335 using WTF::ThreadCondition;
 336 using WTF::ThreadIdentifier;
 337 using WTF::ThreadSafeShared;
 338
 339 #if USE(LOCKFREE_THREADSAFESHARED)
 340 using WTF::atomicDecrement;
 341 using WTF::atomicIncrement;
 342 #endif
 343
 344 using WTF::createThread;
 345 using WTF::currentThread;
 346 using WTF::isMainThread;
 347 using WTF::detachThread;
 348 using WTF::waitForThreadCompletion;
 349
 350 #endif // Threading_h