157257Sdufault/* 257257Sdufault * Copyright (c) 1996-1999 357257Sdufault * HD Associates, Inc. All rights reserved. 457257Sdufault * 557257Sdufault * Redistribution and use in source and binary forms, with or without 657257Sdufault * modification, are permitted provided that the following conditions 757257Sdufault * are met: 857257Sdufault * 1. Redistributions of source code must retain the above copyright 957257Sdufault * notice, this list of conditions and the following disclaimer. 1057257Sdufault * 2. Redistributions in binary form must reproduce the above copyright 1157257Sdufault * notice, this list of conditions and the following disclaimer in the 1257257Sdufault * documentation and/or other materials provided with the distribution. 1357257Sdufault * 3. All advertising materials mentioning features or use of this software 1457257Sdufault * must display the following acknowledgement: 1557257Sdufault * This product includes software developed by HD Associates, Inc 1657257Sdufault * 4. Neither the name of the author nor the names of any co-contributors 1757257Sdufault * may be used to endorse or promote products derived from this software 1857257Sdufault * without specific prior written permission. 1957257Sdufault * 2057257Sdufault * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND 2157257Sdufault * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2257257Sdufault * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2357257Sdufault * ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE 2457257Sdufault * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2557257Sdufault * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2657257Sdufault * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2757257Sdufault * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2857257Sdufault * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2957257Sdufault * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3057257Sdufault * SUCH DAMAGE. 3157257Sdufault * $FreeBSD$ 3257257Sdufault * 3357257Sdufault */ 3457257Sdufault 3557257Sdufault/* XXX: The spec says that if _POSIX_C_SOURCE is defined then 3657257Sdufault * _POSIX_SOURCE is ignored. However, this is similar to 3757257Sdufault * the code in the O'Reilly "POSIX.4" book 3857257Sdufault */ 3957257Sdufault 4057257Sdufault#define _POSIX_VERSION 199309L 4157257Sdufault#define _POSIX_SOURCE 4257257Sdufault#define _POSIX_C_SOURCE 199309L 4357257Sdufault 4457257Sdufault#include <unistd.h> 4557257Sdufault#include <stdlib.h> 4657257Sdufault 4757257Sdufault#include <stdio.h> 4857257Sdufault#include <string.h> 4957257Sdufault#include <errno.h> 5057257Sdufault#include <fcntl.h> 5157257Sdufault#include <sys/mman.h> 5257257Sdufault 5357257Sdufault#include <sched.h> 5457257Sdufault 5557257Sdufault#include "prutil.h" 5657257Sdufault 5757257Sdufaultstatic FILE *verbose; 5857257Sdufault 5957257Sdufaultstatic void 6057257Sdufaultcheckpris(int sched) 6157257Sdufault{ 6257257Sdufault int smin; 6357257Sdufault int smax; 6457257Sdufault 6557257Sdufault errno = 0; 6657257Sdufault 6757257Sdufault if ( (smin = sched_get_priority_min(sched)) == -1 && errno) 6857257Sdufault quit("sched_get_priority_min"); 6957257Sdufault 7057257Sdufault if ( (smax = sched_get_priority_max(sched)) == -1 && errno) 7157257Sdufault quit("sched_get_priority_max"); 7257257Sdufault 7357257Sdufault if (smax - smin + 1 < 32 || smax < smin) { 7457257Sdufault fprintf(stderr, "Illegal priority range for %s: %d to %d\n", 7557257Sdufault sched_text(sched), smin, smax); 7657257Sdufault exit(-1); 7757257Sdufault } 7857257Sdufault 7957257Sdufault if (verbose) 8057257Sdufault fprintf(verbose, "%12s: sched_min %2d sched_max %2d\n", 8157257Sdufault sched_text(sched), smin, smax); 8257257Sdufault} 8357257Sdufault 8457257Sdufault/* Set "try_anyway" to quit if you don't want to go on when 8557257Sdufault * it doesn't look like something should work. 8657257Sdufault */ 8757257Sdufaultstatic void try_anyway(const char *s) 8857257Sdufault{ 8957257Sdufault fputs(s, stderr); 9057257Sdufault fprintf(stderr, "(trying anyway)\n"); 9157257Sdufault errno = 0; 9257257Sdufault} 9357257Sdufault 9457257Sdufaultstatic void q(int line, int code, const char *text) 9557257Sdufault{ 9657257Sdufault if (code == -1) 9757257Sdufault { 9857257Sdufault fprintf(stderr, "Error at line %d:\n", line); 9957257Sdufault perror(text); 10057257Sdufault exit(errno); 10157257Sdufault } 10257257Sdufault} 10357257Sdufault 10457257Sdufaultint sched(int ac, char *av[]) 10557257Sdufault{ 10657257Sdufault int fifo_schedmin, fifo_schedmax; 10757257Sdufault int i; 10857257Sdufault struct sched_param rt_param; 10957257Sdufault int n_instances = 10; 11057257Sdufault int sched; 11157257Sdufault 11257257Sdufault verbose = 0; 11357257Sdufault 11457257Sdufault#if _POSIX_VERSION < 199309 11557257Sdufault try_anyway("The _POSIX_VERSION predates P1003.1B\n"); 11657257Sdufault#endif 11757257Sdufault 11857257Sdufault#if !defined(_POSIX_PRIORITY_SCHEDULING) 11957257Sdufault try_anyway( 12057257Sdufault "The environment does not claim to support Posix scheduling.\n"); 12157257Sdufault#endif 12257257Sdufault 12357257Sdufault /* Is priority scheduling configured? 12457257Sdufault */ 12557257Sdufault errno = 0; 12657257Sdufault if (sysconf(_SC_PRIORITY_SCHEDULING) == -1) { 12757257Sdufault if (errno != 0) { 12857257Sdufault /* This isn't valid - may be a standard violation 12957257Sdufault */ 13057257Sdufault quit("(should not happen) sysconf(_SC_PRIORITY_SCHEDULING)"); 13157257Sdufault } 13257257Sdufault else { 13357257Sdufault try_anyway( 13457257Sdufault "The environment does not have run-time " 13557257Sdufault "support for Posix scheduling.\n"); 13657257Sdufault } 13757257Sdufault } 13857257Sdufault 13957257Sdufault /* Check that the priorities seem reasonable. 14057257Sdufault */ 14157257Sdufault 14257257Sdufault checkpris(SCHED_FIFO); 14357257Sdufault checkpris(SCHED_RR); 14457257Sdufault checkpris(SCHED_OTHER); 14557257Sdufault 14657257Sdufault/* BSD extensions? 14757257Sdufault */ 14857257Sdufault#if defined(SCHED_IDLE) 14957257Sdufault checkpris(SCHED_IDLE); 15057257Sdufault#endif 15157257Sdufault 15257257Sdufault fifo_schedmin = sched_get_priority_min(SCHED_FIFO); 15357257Sdufault fifo_schedmax = sched_get_priority_max(SCHED_FIFO); 15457257Sdufault 15557257Sdufault /* Make sure we can do some basic schedule switching: 15657257Sdufault */ 15757257Sdufault { 15857257Sdufault struct sched_param orig_param, shouldbe; 15957257Sdufault int orig_scheduler = sched_is(__LINE__, &orig_param, -1); 16057257Sdufault 16157257Sdufault if (verbose) 16257257Sdufault fprintf(verbose, 16357257Sdufault "The original scheduler is %s and the priority is %d.\n", 16457257Sdufault sched_text(orig_scheduler), orig_param.sched_priority); 16557257Sdufault 16657257Sdufault /* Basic check: Try to set current settings: 16757257Sdufault */ 16857257Sdufault q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param), 16957257Sdufault "sched_setscheduler: Can't set original scheduler"); 17057257Sdufault 17157257Sdufault rt_param.sched_priority = fifo_schedmin; 17257257Sdufault 17357257Sdufault q(__LINE__, sched_setscheduler(0, SCHED_FIFO, &rt_param), 17457257Sdufault "sched_setscheduler SCHED_FIFO"); 17557257Sdufault 17657257Sdufault (void)sched_is(__LINE__, 0, SCHED_FIFO); 17757257Sdufault 17857257Sdufault q(__LINE__, sched_getparam(0, &shouldbe), "sched_getparam"); 17957257Sdufault 18057257Sdufault if (shouldbe.sched_priority != fifo_schedmin) 18157257Sdufault quit("sched_setscheduler wrong priority (min)"); 18257257Sdufault 18357257Sdufault rt_param.sched_priority = fifo_schedmin; 18457257Sdufault 18557257Sdufault q(__LINE__, sched_setparam(0, &rt_param), 18657257Sdufault "sched_setparam to fifo_schedmin"); 18757257Sdufault 18857257Sdufault rt_param.sched_priority = fifo_schedmin + 1; 18957257Sdufault 19057257Sdufault q(__LINE__, sched_setparam(0, &rt_param), 19157257Sdufault "sched_setparam to fifo_schedmin + 1"); 19257257Sdufault 19357257Sdufault q(__LINE__, sched_getparam(0, &shouldbe), 19457257Sdufault "sched_getparam"); 19557257Sdufault 19657257Sdufault if (shouldbe.sched_priority != fifo_schedmin + 1) 19757257Sdufault quit("sched_setscheduler wrong priority (min + 1)"); 19857257Sdufault 19957257Sdufault q(__LINE__, sched_setscheduler(0, SCHED_RR, &rt_param), 20057257Sdufault "sched_setscheduler SCHED_RR"); 20157257Sdufault 20257257Sdufault (void)sched_is(__LINE__, 0, SCHED_RR); 20357257Sdufault 20457257Sdufault q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param), 20557257Sdufault "sched_setscheduler restoring original scheduler"); 20657257Sdufault 20757257Sdufault (void)sched_is(__LINE__, 0, orig_scheduler); 20857257Sdufault } 20957257Sdufault 21057257Sdufault 21157257Sdufault { 21257257Sdufault#define NAM "P1003_1b_schedXXXX" 21357257Sdufault char nam[L_tmpnam]; 21457257Sdufault int fd; 21557257Sdufault pid_t p; 21657257Sdufault pid_t *lastrun; 21757257Sdufault 21857257Sdufault strcpy(nam, NAM); 21957257Sdufault if (tmpnam(nam) != nam) 22057257Sdufault q(__LINE__, errno, "tmpnam " NAM); 22157257Sdufault q(__LINE__, (fd = open(nam, O_RDWR|O_CREAT, 0666)), 22257257Sdufault "open " NAM); 22357257Sdufault 22457257Sdufault (void)unlink(nam); 22557257Sdufault 22657257Sdufault p = (pid_t)0; 22757257Sdufault 22857257Sdufault write(fd, &p, sizeof(p)); 22957257Sdufault 23057257Sdufault q(__LINE__, (int)(lastrun = mmap(0, sizeof(*lastrun), PROT_READ|PROT_WRITE, 23157257Sdufault MAP_SHARED, fd, 0)), "mmap"); 23257257Sdufault 23357257Sdufault /* Set our priority at the highest: 23457257Sdufault */ 23557257Sdufault sched = SCHED_FIFO; 23657257Sdufault rt_param.sched_priority = fifo_schedmax; 23757257Sdufault q(__LINE__, sched_setscheduler(0, sched, &rt_param), 23857257Sdufault "sched_setscheduler sched"); 23957257Sdufault 24057257Sdufault for (i = 0; i < n_instances; i++) 24157257Sdufault { 24257257Sdufault pid_t me; 24357257Sdufault 24457257Sdufault /* XXX This is completely bogus. The children never run. 24557257Sdufault */ 24657257Sdufault if ((me = fork()) != 0) 24757257Sdufault { 24857257Sdufault /* Parent. 24957257Sdufault */ 25057257Sdufault (void)sched_is(__LINE__, 0, sched); 25157257Sdufault 25257257Sdufault /* Lower our priority: 25357257Sdufault */ 25457257Sdufault rt_param.sched_priority--; 25557257Sdufault 25657257Sdufault q(__LINE__, sched_setscheduler(0, sched, &rt_param), 25757257Sdufault "sched_setscheduler sched"); 25857257Sdufault 25957257Sdufault while (1) 26057257Sdufault { 26157257Sdufault q(__LINE__, sched_getparam(0, &rt_param), "sched_getparam"); 26257257Sdufault 26357257Sdufault rt_param.sched_priority--; 26457257Sdufault 26557257Sdufault 26657257Sdufault if (rt_param.sched_priority < fifo_schedmin) 26757257Sdufault exit(0); 26857257Sdufault 26957257Sdufault *lastrun = me; 27057257Sdufault q(__LINE__, sched_setparam(0, &rt_param), "sched_setparam"); 27157257Sdufault 27257257Sdufault if (*lastrun == me) 27357257Sdufault { 27457257Sdufault /* The child will run twice 27557257Sdufault * at the end: 27657257Sdufault */ 27757257Sdufault if (!me || rt_param.sched_priority != 0) 27857257Sdufault { 27957257Sdufault fprintf(stderr, 28057257Sdufault "ran process %ld twice at priority %d\n", 28157257Sdufault (long)me, rt_param.sched_priority + 1); 28257257Sdufault exit(-1); 28357257Sdufault } 28457257Sdufault } 28557257Sdufault } 28657257Sdufault } 28757257Sdufault } 28857257Sdufault } 28957257Sdufault 29057257Sdufault return 0; 29157257Sdufault} 29257257Sdufault#ifdef STANDALONE_TESTS 29357257Sdufaultint main(int argc, char *argv[]) { return sched(argc, argv); } 29457257Sdufault#endif 295