1 /*
2 * Copyright (c) 1996-1999
3 * HD Associates, Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
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
checkpris(int sched)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 */
try_anyway(const char * s)87 static void try_anyway(const char *s)
88 {
89 fputs(s, stderr);
90 fprintf(stderr, "(trying anyway)\n");
91 errno = 0;
92 }
93
q(int line,int code,const char * text)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
sched(int ac,char * av[])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
main(int argc,char * argv[])293 int main(int argc, char *argv[]) { return sched(argc, argv); }
294 #endif
295