PidStopperLinux.cpp

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/*
 * This file is part of ArmarX.
 *
 * Copyright (C) 2011-2016, High Performance Humanoid Technologies (H2T), Karlsruhe Institute of Technology (KIT), all rights reserved.
 *
 * ArmarX is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * ArmarX 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 this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * @package    ArmarXCore::core
 * @author     Nicola Miskowiec
 * @date       2016
 * @copyright  http://www.gnu.org/licenses/gpl-2.0.txt
 *             GNU General Public License
 */
 
 
#include "PidStopperLinux.h"
 
#include <errno.h>
#include <signal.h>
#include <string.h>
 
#include <sys/types.h>
 
#include <ArmarXCore/core/logging/Logging.h>
 
using namespace ScenarioManager;
using namespace Exec;
using namespace Data_Structure;
 
namespace
{
    /**
     * Sends `signalNumber` to `pid` and reports a failure to do so.
     *
     * kill() failing is not a detail: ESRCH means the process was already gone, and EPERM means
     * the pid belongs to a process this ScenarioManager is not allowed to signal - which almost
     * always means it is not the application at all, but an unrelated process that was handed the
     * recycled pid. Both used to be discarded silently, leaving a stop that did nothing and then
     * timed out with no indication of why.
     */
    void
    Signal(int pid, int signalNumber, const std::string& signalName, const std::string& name)
    {
        if (::kill(pid, signalNumber) == 0)
        {
            return;
        }
 
        const int errorNumber = errno;
        ARMARX_WARNING_S << "Could not send " << signalName << " to application " << name
                         << " (pid " << pid << "): " << ::strerror(errorNumber)
                         << (errorNumber == EPERM
                                 ? ". The pid belongs to a process this ScenarioManager may not "
                                   "signal, so it is most likely not this application."
                                 : "");
    }
} // namespace
 
void
PidStopperLinux::stop(ApplicationInstancePtr application)
{
    const int pid = application->getPid();
    if (pid > 0)
    {
        ARMARX_INFO_S << "Stopping application " << application->getName() << " (pid " << pid
                      << ")";
        Signal(pid, SIGTERM, "SIGTERM", application->getName());
    }
    else
    {
        ARMARX_WARNING_S << "Cannot stop application " << application->getName()
                         << ": no pid known for it (it is not running, or it was not started by "
                            "this ScenarioManager).";
    }
}
 
void
PidStopperLinux::kill(ApplicationInstancePtr application)
{
    const int pid = application->getPid();
    if (pid > 0)
    {
        ARMARX_INFO_S << "Killing application " << application->getName() << " (pid " << pid << ")";
        Signal(pid, SIGKILL, "SIGKILL", application->getName());
    }
    else
    {
        ARMARX_WARNING_S << "Cannot kill application " << application->getName()
                         << ": no pid known for it (it is not running, or it was not started by "
                            "this ScenarioManager).";
    }
}