mosesdecoder/moses/ThreadPool.cpp
2012-11-12 19:56:18 +00:00

108 lines
2.7 KiB
C++

// $Id: ThreadPool.cpp 3045 2010-04-05 13:07:29Z hieuhoang1972 $
/***********************************************************************
Moses - factored phrase-based language decoder
Copyright (C) 2009 University of Edinburgh
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
***********************************************************************/
#include "ThreadPool.h"
#ifdef WITH_THREADS
using namespace std;
using namespace Moses;
namespace Moses
{
ThreadPool::ThreadPool( size_t numThreads )
: m_stopped(false), m_stopping(false), m_queueLimit(0)
{
for (size_t i = 0; i < numThreads; ++i) {
m_threads.create_thread(boost::bind(&ThreadPool::Execute,this));
}
}
void ThreadPool::Execute()
{
do {
Task* task = NULL;
{
// Find a job to perform
boost::mutex::scoped_lock lock(m_mutex);
if (m_tasks.empty() && !m_stopped) {
m_threadNeeded.wait(lock);
}
if (!m_stopped && !m_tasks.empty()) {
task = m_tasks.front();
m_tasks.pop();
}
}
//Execute job
if (task) {
task->Run();
if (task->DeleteAfterExecution()) {
delete task;
}
}
m_threadAvailable.notify_all();
} while (!m_stopped);
}
void ThreadPool::Submit( Task* task )
{
boost::mutex::scoped_lock lock(m_mutex);
if (m_stopping) {
throw runtime_error("ThreadPool stopping - unable to accept new jobs");
}
while (m_queueLimit > 0 && m_tasks.size() >= m_queueLimit) {
m_threadAvailable.wait(lock);
}
m_tasks.push(task);
m_threadNeeded.notify_all();
}
void ThreadPool::Stop(bool processRemainingJobs)
{
{
//prevent more jobs from being added to the queue
boost::mutex::scoped_lock lock(m_mutex);
if (m_stopped) return;
m_stopping = true;
}
if (processRemainingJobs) {
boost::mutex::scoped_lock lock(m_mutex);
//wait for queue to drain.
while (!m_tasks.empty() && !m_stopped) {
m_threadAvailable.wait(lock);
}
}
//tell all threads to stop
{
boost::mutex::scoped_lock lock(m_mutex);
m_stopped = true;
}
m_threadNeeded.notify_all();
m_threads.join_all();
}
}
#endif //WITH_THREADS