uhd

//

// Copyright 2010-2011 Ettus Research LLC

//

// This program 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 3 of the License, or

// (at your option) any later version.

//

// This program 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/>.

//

#include <uhd/utils/thread_priority.hpp>

#include <uhd/utils/warning.hpp>

#include <uhd/exception.hpp>

#include <boost/format.hpp>

#include <iostream>

bool uhd::set_thread_priority_safe(float priority, bool realtime){

    try{

        set_thread_priority(priority, realtime);

        return true;

    }catch(const std::exception &e){

        uhd::warning::post(str(boost::format(

            "%s\n"

            "Failed to set thread priority %d (%s):\n"

            "Performance may be negatively affected.\n"

            "See the general application notes.\n"

        ) % e.what() % priority % (realtime?"realtime":"")));

        return false;

    }

}

static void check_priority_range(float priority){

    if (priority > +1.0 or priority < -1.0)

        throw std::range_error("priority out of range [-1.0, +1.0]");

}

/***********************************************************************

 * Pthread API to set priority

 **********************************************************************/

#ifdef HAVE_PTHREAD_SETSCHEDPARAM

    #include <pthread.h>

    void uhd::set_thread_priority(float priority, bool realtime){

        check_priority_range(priority);

        //when realtime is not enabled, use sched other

        int policy = (realtime)? SCHED_RR : SCHED_OTHER;

        //we cannot have below normal priority, set to zero

        if (priority < 0) priority = 0;

        //get the priority bounds for the selected policy

        int min_pri = sched_get_priority_min(policy);

        int max_pri = sched_get_priority_max(policy);

        if (min_pri == -1 or max_pri == -1) throw uhd::os_error("error in sched_get_priority_min/max");

        //set the new priority and policy

        sched_param sp;

        sp.sched_priority = int(priority*(max_pri - min_pri)) + min_pri;

        int ret = pthread_setschedparam(pthread_self(), policy, &sp);

        if (ret != 0) throw uhd::os_error("error in pthread_setschedparam");

    }

#endif /* HAVE_PTHREAD_SETSCHEDPARAM */

/***********************************************************************

 * Windows API to set priority

 **********************************************************************/

#ifdef HAVE_WIN_SETTHREADPRIORITY

    #include <windows.h>

    void uhd::set_thread_priority(float priority, bool realtime){

        check_priority_range(priority);

        //set the priority class on the process

        int pri_class = (realtime)? REALTIME_PRIORITY_CLASS : NORMAL_PRIORITY_CLASS;

        if (SetPriorityClass(GetCurrentProcess(), pri_class) == 0)

            throw uhd::os_error("error in SetPriorityClass");

        //scale the priority value to the constants

        int priorities[] = {

            THREAD_PRIORITY_IDLE, THREAD_PRIORITY_LOWEST, THREAD_PRIORITY_BELOW_NORMAL, THREAD_PRIORITY_NORMAL,

            THREAD_PRIORITY_ABOVE_NORMAL, THREAD_PRIORITY_HIGHEST, THREAD_PRIORITY_TIME_CRITICAL

        };

        size_t pri_index = size_t((priority+1.0)*6/2.0); // -1 -> 0, +1 -> 6

        //set the thread priority on the thread

        if (SetThreadPriority(GetCurrentThread(), priorities[pri_index]) == 0)

            throw uhd::os_error("error in SetThreadPriority");

    }

#endif /* HAVE_WIN_SETTHREADPRIORITY */

/***********************************************************************

 * Unimplemented API to set priority

 **********************************************************************/

#ifdef HAVE_LOAD_MODULES_DUMMY

    void uhd::set_thread_priority(float, bool){

        throw uhd::not_implemented_error("set thread priority not implemented");

    }

#endif /* HAVE_LOAD_MODULES_DUMMY */