opm-simulators/opm/models/parallel/threadmanager.hh
2024-08-12 15:49:47 +02:00

142 lines
4.4 KiB
C++

// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
OPM 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
Consult the COPYING file in the top-level source directory of this
module for the precise wording of the license and the list of
copyright holders.
*/
/*!
* \file
* \copydoc Opm::ThreadManager
*/
#ifndef EWOMS_THREAD_MANAGER_HH
#define EWOMS_THREAD_MANAGER_HH
#ifdef _OPENMP
#include <omp.h>
#endif
#include <opm/models/discretization/common/fvbaseparameters.hh>
#include <opm/models/utils/parametersystem.hh>
#include <opm/models/utils/propertysystem.hh>
#include <dune/common/version.hh>
namespace Opm {
/*!
* \brief Simplifies multi-threaded capabilities.
*/
template <class TypeTag>
class ThreadManager
{
public:
enum {
#if defined(_OPENMP) || DOXYGEN
//! Specify whether OpenMP is really available or not
isFake = false
#else
isFake = true
#endif
};
/*!
* \brief Register all run-time parameters of the thread manager.
*/
static void registerParameters()
{
Parameters::Register<Parameters::ThreadsPerProcess>
("The maximum number of threads to be instantiated per process "
"('-1' means 'automatic')");
}
/*!
* \brief Initialize number of threads used thread manager.
*
* \param queryCommandLineParameter if set to true we will query ThreadsPerProcess
* and if set (disregard the environment variable OPM_NUM_THREADS).
* If false we will assume that the number of OpenMP threads is already set
* outside of this function (e.g. by OPM_NUM_THREADS or in the simulator by
* the ThreadsPerProcess parameter).
*/
static void init(bool queryCommandLineParameter = true)
{
if (queryCommandLineParameter)
{
numThreads_ = Parameters::Get<Parameters::ThreadsPerProcess>();
// some safety checks. This is pretty ugly macro-magic, but so what?
#if !defined(_OPENMP)
if (numThreads_ != 1 && numThreads_ != -1)
throw std::invalid_argument("OpenMP is not available. The only valid values for "
"threads-per-process is 1 and -1 but it is "+std::to_string(numThreads_)+"!");
numThreads_ = 1;
#elif !defined NDEBUG && defined DUNE_INTERFACECHECK
if (numThreads_ != 1)
throw std::invalid_argument("You explicitly enabled Barton-Nackman interface checking in Dune. "
"The Dune implementation of this is currently incompatible with "
"thread parallelism!");
numThreads_ = 1;
#else
if (numThreads_ == 0)
throw std::invalid_argument("Zero threads per process are not possible: It must be at least 1, "
"(or -1 for 'automatic')!");
#endif
#ifdef _OPENMP
// actually limit the number of threads
if (numThreads_ > 0)
omp_set_num_threads(numThreads_);
#endif
}
#ifdef _OPENMP
// get the number of threads which are used in the end.
numThreads_ = omp_get_max_threads();
#endif
}
/*!
* \brief Return the maximum number of threads of the current process.
*/
static unsigned maxThreads()
{ return static_cast<unsigned>(numThreads_); }
/*!
* \brief Return the index of the current OpenMP thread
*/
static unsigned threadId()
{
#ifdef _OPENMP
return static_cast<unsigned>(omp_get_thread_num());
#else
return 0;
#endif
}
private:
static int numThreads_;
};
template <class TypeTag>
int ThreadManager<TypeTag>::numThreads_ = 1;
} // namespace Opm
#endif