/* * Copyright (C) 2020 Mark Hills * * 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 #include #include #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; }