/* * Copyright (C) 2011 University of Szeged * Copyright (C) 2011 Gabor Loki <loki@webkit.org> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL UNIVERSITY OF SZEGED OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef ParallelJobs_h #define ParallelJobs_h #include "platform/Task.h" #include "public/platform/Platform.h" #include "public/platform/WebThread.h" #include "wtf/Assertions.h" #include "wtf/Noncopyable.h" #include "wtf/OwnPtr.h" #include "wtf/Vector.h" // Usage: // // // Initialize parallel jobs // ParallelJobs<TypeOfParameter> parallelJobs(&worker, requestedNumberOfJobs); // // // Fill the parameter array // for(i = 0; i < parallelJobs.numberOfJobs(); ++i) { // TypeOfParameter& params = parallelJobs.parameter(i); // params.attr1 = localVars ... // ... // } // // // Execute parallel jobs // parallelJobs.execute(); // namespace WebCore { template<typename Type> class ParallelJobs { WTF_MAKE_NONCOPYABLE(ParallelJobs); WTF_MAKE_FAST_ALLOCATED; public: typedef void (*WorkerFunction)(Type*); ParallelJobs(WorkerFunction func, size_t requestedJobNumber) : m_func(func) { size_t numberOfJobs = std::max(static_cast<size_t>(2), std::min(requestedJobNumber, blink::Platform::current()->numberOfProcessors())); m_parameters.grow(numberOfJobs); // The main thread can execute one job, so only create requestJobNumber - 1 threads. for (size_t i = 0; i < numberOfJobs - 1; ++i) { OwnPtr<blink::WebThread> thread = adoptPtr(blink::Platform::current()->createThread("Unfortunate parallel worker")); m_threads.append(thread.release()); } } size_t numberOfJobs() { return m_parameters.size(); } Type& parameter(size_t i) { return m_parameters[i]; } void execute() { for (size_t i = 0; i < numberOfJobs() - 1; ++i) m_threads[i]->postTask(new Task(WTF::bind(m_func, ¶meter(i)))); m_func(¶meter(numberOfJobs() - 1)); m_threads.clear(); } private: WorkerFunction m_func; Vector<OwnPtr<blink::WebThread> > m_threads; Vector<Type> m_parameters; }; } // namespace WebCore #endif // ParallelJobs_h