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/*
* Copyright (C) 2020 Mark Hills <mark@xwax.org>
*
* This program 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.
*
* 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 version 2 for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*
*/
#include <sched.h>
#include <stdio.h>
#include <unistd.h>
#include "sched.h"
#define REALTIME_PRIORITY 80
int go_realtime(void)
{
int max_pri;
struct sched_param sp;
if (sched_getparam(0, &sp)) {
perror("sched_getparam");
return -1;
}
max_pri = sched_get_priority_max(SCHED_FIFO);
sp.sched_priority = REALTIME_PRIORITY;
if (sp.sched_priority > max_pri) {
fprintf(stderr, "Invalid priority (maximum %d)\n", max_pri);
return -1;
}
if (sched_setscheduler(0, SCHED_FIFO, &sp)) {
perror("sched_setscheduler");
return -1;
}
return 0;
}
int go_daemon(const char *pid_file)
{
FILE *f;
if (daemon(0, 0) == -1) {
perror("daemon");
return -1;
}
if (!pid_file)
return 0;
f = fopen(pid_file, "w");
if (!f) {
perror("fopen");
return -1;
}
fprintf(f, "%d", getpid());
if (fclose(f) != 0) {
perror("fclose");
return -1;
}
return 0;
}