tools/regression/p1003_1b/sched.c

   1 /*
   2  * Copyright (c) 1996-1999
   3  *      HD Associates, Inc.  All rights reserved.
   4  *
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   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by HD Associates, Inc
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  * $FreeBSD: src/tools/regression/p1003_1b/sched.c,v 1.1 2000/02/16 14:28:42 dufault Exp $
  32  *
  33  */
  34
  35 /* XXX: The spec says that if _POSIX_C_SOURCE is defined then
  36  *      _POSIX_SOURCE is ignored.  However, this is similar to
  37  *      the code in the O'Reilly "POSIX.4" book
  38  */
  39
  40 #define _POSIX_VERSION 199309L
  41 #define _POSIX_SOURCE
  42 #define _POSIX_C_SOURCE 199309L
  43
  44 #include <unistd.h>
  45 #include <stdlib.h>
  46
  47 #include <stdio.h>
  48 #include <string.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <sys/mman.h>
  52
  53 #include <sys/sched.h>
  54
  55 #include "prutil.h"
  56
  57 static FILE *verbose;
  58
  59 static void
  60 checkpris(int sched)
  61 {
  62         int smin;
  63         int smax;
  64
  65         errno = 0;
  66
  67         if ( (smin = sched_get_priority_min(sched)) == -1 && errno)
  68                 quit("sched_get_priority_min");
  69
  70         if ( (smax = sched_get_priority_max(sched)) == -1 && errno)
  71                 quit("sched_get_priority_max");
  72
  73         if (smax - smin + 1 < 32 || smax < smin) {
  74                 fprintf(stderr, "Illegal priority range for %s: %d to %d\n",
  75                 sched_text(sched), smin, smax);
  76                 exit(-1);
  77         }
  78
  79         if (verbose)
  80                 fprintf(verbose, "%12s: sched_min %2d sched_max %2d\n",
  81                 sched_text(sched), smin, smax);
  82 }
  83
  84 /* Set "try_anyway" to quit if you don't want to go on when
  85  * it doesn't look like something should work.
  86  */
  87 static void try_anyway(const char *s)
  88 {
  89         fputs(s, stderr);
  90         fprintf(stderr, "(trying anyway)\n");
  91         errno = 0;
  92 }
  93
  94 static void q(int line, int code, const char *text)
  95 {
  96         if (code == -1)
  97         {
  98                 fprintf(stderr, "Error at line %d:\n", line);
  99                 perror(text);
 100                 exit(errno);
 101         }
 102 }
 103
 104 int sched(int ac, char *av[])
 105 {
 106         int fifo_schedmin, fifo_schedmax;
 107         int i;
 108         struct sched_param rt_param;
 109         int n_instances = 10;
 110         int sched;
 111
 112         verbose = NULL;
 113
 114 #if _POSIX_VERSION < 199309
 115         try_anyway("The _POSIX_VERSION predates P1003.1B\n");
 116 #endif
 117
 118 #if !defined(_POSIX_PRIORITY_SCHEDULING)
 119         try_anyway(
 120         "The environment does not claim to support Posix scheduling.\n");
 121 #endif
 122
 123         /* Is priority scheduling configured?
 124          */
 125         errno = 0;
 126         if (sysconf(_SC_PRIORITY_SCHEDULING) == -1) {
 127                 if (errno != 0) {
 128                         /* This isn't valid - may be a standard violation
 129                          */
 130                         quit("(should not happen) sysconf(_SC_PRIORITY_SCHEDULING)");
 131                 }
 132                 else {
 133                         try_anyway(
 134                         "The environment does not have run-time "
 135                         "support for Posix scheduling.\n");
 136                 }
 137         }
 138
 139         /* Check that the priorities seem reasonable.
 140          */
 141
 142         checkpris(SCHED_FIFO);
 143         checkpris(SCHED_RR);
 144         checkpris(SCHED_OTHER);
 145
 146 /* BSD extensions?
 147  */
 148 #if defined(SCHED_IDLE)
 149         checkpris(SCHED_IDLE);
 150 #endif
 151
 152         fifo_schedmin = sched_get_priority_min(SCHED_FIFO);
 153         fifo_schedmax = sched_get_priority_max(SCHED_FIFO);
 154
 155         /* Make sure we can do some basic schedule switching:
 156          */
 157         {
 158                 struct sched_param orig_param, shouldbe;
 159                 int orig_scheduler = sched_is(__LINE__, &orig_param, -1);
 160
 161                 if (verbose)
 162                         fprintf(verbose,
 163                         "The original scheduler is %s and the priority is %d.\n",
 164                         sched_text(orig_scheduler), orig_param.sched_priority);
 165
 166                 /* Basic check: Try to set current settings:
 167                  */
 168                 q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param),
 169                         "sched_setscheduler: Can't set original scheduler");
 170
 171                 rt_param.sched_priority = fifo_schedmin;
 172
 173                 q(__LINE__, sched_setscheduler(0, SCHED_FIFO, &rt_param),
 174                 "sched_setscheduler SCHED_FIFO");
 175
 176                 (void)sched_is(__LINE__, 0, SCHED_FIFO);
 177
 178                 q(__LINE__, sched_getparam(0, &shouldbe), "sched_getparam");
 179
 180                 if (shouldbe.sched_priority != fifo_schedmin)
 181                         quit("sched_setscheduler wrong priority (min)");
 182
 183                 rt_param.sched_priority = fifo_schedmin;
 184
 185                 q(__LINE__, sched_setparam(0, &rt_param),
 186                         "sched_setparam to fifo_schedmin");
 187
 188                 rt_param.sched_priority = fifo_schedmin + 1;
 189
 190                 q(__LINE__, sched_setparam(0, &rt_param),
 191                         "sched_setparam to fifo_schedmin + 1");
 192
 193                 q(__LINE__, sched_getparam(0, &shouldbe),
 194                         "sched_getparam");
 195
 196                 if (shouldbe.sched_priority != fifo_schedmin + 1)
 197                         quit("sched_setscheduler wrong priority (min + 1)");
 198
 199                 q(__LINE__, sched_setscheduler(0, SCHED_RR, &rt_param),
 200                         "sched_setscheduler SCHED_RR");
 201
 202                 (void)sched_is(__LINE__, 0, SCHED_RR);
 203
 204                 q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param),
 205                         "sched_setscheduler restoring original scheduler");
 206
 207                 (void)sched_is(__LINE__, 0, orig_scheduler);
 208         }
 209
 210
 211         {
 212 #define NAM "P1003_1b_schedXXXX"
 213                 char nam[L_tmpnam];
 214                 int fd;
 215                 pid_t p;
 216                 pid_t *lastrun;
 217
 218                 strcpy(nam, NAM);
 219                 if (tmpnam(nam) != nam)
 220                         q(__LINE__, errno, "tmpnam " NAM);
 221                 q(__LINE__, (fd = open(nam, O_RDWR|O_CREAT, 0666)),
 222                         "open " NAM);
 223
 224                 (void)unlink(nam);
 225
 226                 p = (pid_t)0;
 227
 228                 write(fd, &p, sizeof(p));
 229
 230                 q(__LINE__,  (int)(lastrun = mmap(0, sizeof(*lastrun), PROT_READ|PROT_WRITE,
 231                 MAP_SHARED, fd, 0)), "mmap");
 232
 233                 /* Set our priority at the highest:
 234                  */
 235                 sched = SCHED_FIFO;
 236                 rt_param.sched_priority = fifo_schedmax;
 237                 q(__LINE__, sched_setscheduler(0, sched, &rt_param),
 238                 "sched_setscheduler sched");
 239
 240                 for (i = 0; i < n_instances; i++)
 241                 {
 242                         pid_t me;
 243
 244                         /* XXX This is completely bogus.  The children never run.
 245                          */
 246                         if ((me = fork()) != 0)
 247                         {
 248                                 /* Parent.
 249                                  */
 250                                 (void)sched_is(__LINE__, 0, sched);
 251
 252                                 /* Lower our priority:
 253                                  */
 254                                 rt_param.sched_priority--;
 255
 256                                 q(__LINE__, sched_setscheduler(0, sched, &rt_param),
 257                                 "sched_setscheduler sched");
 258
 259                                 while (1)
 260                                 {
 261                                         q(__LINE__, sched_getparam(0, &rt_param), "sched_getparam");
 262
 263                                         rt_param.sched_priority--;
 264
 265
 266                                         if (rt_param.sched_priority < fifo_schedmin)
 267                                                 exit(0);
 268
 269                                         *lastrun = me;
 270                                         q(__LINE__, sched_setparam(0, &rt_param), "sched_setparam");
 271
 272                                         if (*lastrun == me)
 273                                         {
 274                                                 /* The child will run twice
 275                                                  * at  the end:
 276                                                  */
 277                                                 if (!me || rt_param.sched_priority != 0)
 278                                                 {
 279                                                         fprintf(stderr,
 280                                                         "ran process %ld twice at priority %d\n",
 281                                                         (long)me, rt_param.sched_priority + 1);
 282                                                         exit(-1);
 283                                                 }
 284                                         }
 285                                 }
 286                         }
 287                 }
 288         }
 289
 290         return 0;
 291 }
 292 #ifdef STANDALONE_TESTS
 293 int main(int argc, char *argv[]) { return sched(argc, argv); }
 294 #endif