1/*
2 * Copyright (C) 2011 University of Szeged
3 * Copyright (C) 2011 Gabor Loki <loki@webkit.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
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 *
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.
26 */
27
28#ifndef ParallelJobsOpenMP_h
29#define ParallelJobsOpenMP_h
30
31#if ENABLE(THREADING_OPENMP)
32
33#include <omp.h>
34
35namespace WTF {
36
37class ParallelEnvironment {
38    WTF_MAKE_NONCOPYABLE(ParallelEnvironment);
39public:
40    typedef void (*ThreadFunction)(void*);
41
42    ParallelEnvironment(ThreadFunction threadFunction, size_t sizeOfParameter, int requestedJobNumber) :
43        m_threadFunction(threadFunction),
44        m_sizeOfParameter(sizeOfParameter)
45    {
46        int maxNumberOfThreads = omp_get_max_threads();
47
48        if (!requestedJobNumber || requestedJobNumber > maxNumberOfThreads)
49            requestedJobNumber = maxNumberOfThreads;
50
51        ASSERT(requestedJobNumber > 0);
52
53        m_numberOfJobs = requestedJobNumber;
54
55    }
56
57    int numberOfJobs()
58    {
59        return m_numberOfJobs;
60    }
61
62    void execute(unsigned char* parameters)
63    {
64        omp_set_num_threads(m_numberOfJobs);
65
66#pragma omp parallel for
67        for (int i = 0; i < m_numberOfJobs; ++i)
68            (*m_threadFunction)(parameters + i * m_sizeOfParameter);
69    }
70
71private:
72    ThreadFunction m_threadFunction;
73    size_t m_sizeOfParameter;
74    int m_numberOfJobs;
75};
76
77} // namespace WTF
78
79#endif // ENABLE(THREADING_OPENMP)
80
81#endif // ParallelJobsOpenMP_h
82