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