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// -*- 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
*
* \brief This file serves as an example of how to use the tasklet mechanism for
* asynchronous work, especially for tasklets that fail.
*/
// Note: we do not use boost.test as it does not cleanly combine with fork() usage
#include <chrono>
#include <iostream>
#include <mutex>
#include <thread>
#include <sys/wait.h>
#include <unistd.h>
#include <cassert>
#include "config.h"
#include <opm/models/parallel/tasklets.hpp>
std::mutex outputMutex;
// The runner is created on the heap for the assertion and outputs in the run function of the tasklets.
std::unique_ptr<Opm::TaskletRunner> runner{};
class SleepTasklet : public Opm::TaskletInterface
{
public:
SleepTasklet(int mseconds, int id)
: mseconds_(mseconds),
id_(id)
{}
void run() override
{
assert(0 <= runner->workerThreadIndex() && runner->workerThreadIndex() < runner->numWorkerThreads());
std::cout << "Sleep tasklet " << id_ << " of " << mseconds_ << " ms starting sleep on worker thread " << runner->workerThreadIndex() << std::endl;
std::this_thread::sleep_for(std::chrono::milliseconds(mseconds_));
std::lock_guard<std::mutex> guard(outputMutex);
std::cout << "Sleep tasklet " << id_ << " of " << mseconds_ << " ms completed by worker thread " << runner->workerThreadIndex() << std::endl;
}
private:
int mseconds_;
int id_;
};
class FailingSleepTasklet : public Opm::TaskletInterface
{
public:
explicit FailingSleepTasklet(int mseconds)
: mseconds_(mseconds)
{}
void run() override
{
std::this_thread::sleep_for(std::chrono::milliseconds(mseconds_));
std::lock_guard<std::mutex> guard(outputMutex);
std::cout << "Failing sleep tasklet of " << mseconds_ << " ms failing now, on work thread " << runner->workerThreadIndex() << std::endl;
throw std::logic_error("Intentional failure for testing");
}
private:
int mseconds_;
};
void execute () {
int numWorkers = 2;
runner = std::make_unique<Opm::TaskletRunner>(numWorkers);
// the master thread is not a worker thread
assert(runner->workerThreadIndex() < 0);
assert(runner->numWorkerThreads() == numWorkers);
// Dispatch some successful tasklets
for (int i = 0; i < 5; ++i) {
runner->barrier();
if (runner->failure()) {
exit(EXIT_FAILURE);
}
auto st = std::make_shared<SleepTasklet>(10,i);
runner->dispatch(st);
}
runner->barrier();
if (runner->failure()) {
exit(EXIT_FAILURE);
}
// Dispatch a failing tasklet
auto failingSleepTasklet = std::make_shared<FailingSleepTasklet>(100);
runner->dispatch(failingSleepTasklet);
// Dispatch more successful tasklets
for (int i = 5; i < 10; ++i) {
runner->barrier();
if (runner->failure()) {
exit(EXIT_FAILURE);
}
auto st = std::make_shared<SleepTasklet>(10,i);
runner->dispatch(st);
}
std::cout << "before barrier" << std::endl;
runner->barrier();
}
int main()
{
pid_t pid = fork(); // Create a new process, such that this child process can call exit(EXIT_FAILURE)
if (pid == -1) {
assert(0 && "Fork failed");
} else if (pid == 0) {
// Child process
execute();
_exit(0); // Should never reach here
} else {
// Parent process
std::cout << "Checking failure of child process with parent process, process id " << pid << std::endl;
int status;
waitpid(pid, &status, 0);
assert(WIFEXITED(status)); // Check if the child process exited
assert(WEXITSTATUS(status) == EXIT_FAILURE); // Check if the exit status is EXIT_FAILURE
}
}
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