2 * Copyright (C) 2011 University of Szeged
3 * Copyright (C) 2011 Gabor Loki <loki@webkit.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
15 * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #ifndef ParallelJobsLibdispatch_h
29 #define ParallelJobsLibdispatch_h
31 #if ENABLE(THREADING_LIBDISPATCH)
33 #include <dispatch/dispatch.h>
37 static const int maxParallelThreads = 2;
39 class ParallelEnvironment {
40 WTF_MAKE_FAST_ALLOCATED;
42 typedef void (*ThreadFunction)(void*);
44 ParallelEnvironment(ThreadFunction threadFunction, size_t sizeOfParameter, int requestedJobNumber) :
45 m_threadFunction(threadFunction),
46 m_sizeOfParameter(sizeOfParameter)
48 if (!requestedJobNumber || requestedJobNumber > maxParallelThreads)
49 requestedJobNumber = maxParallelThreads;
51 ASSERT(requestedJobNumber > 0);
53 m_numberOfJobs = requestedJobNumber;
58 return m_numberOfJobs;
61 void execute(unsigned char* parameters)
63 // libdispatch is NOT supported inside a template
64 dispatch_queue_t parallelJobsQueue = dispatch_queue_create("ParallelJobs", 0);
66 for (int i = 0; i < m_numberOfJobs - 1; ++i) {
67 dispatch_async(parallelJobsQueue, ^{(*m_threadFunction)(parameters);});
68 parameters += m_sizeOfParameter;
71 // The work for the main thread. Wait until all jobs are done.
72 dispatch_sync(parallelJobsQueue, ^{(*m_threadFunction)(parameters);});
76 ThreadFunction m_threadFunction;
77 size_t m_sizeOfParameter;
83 #endif // ENABLE(THREADING_LIBDISPATCH)
85 #endif // ParallelJobsLibdispatch_h