1 /* Test program for process CPU clocks.
2 Copyright (C) 2004 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <time.h>
22 #include <unistd.h>
23 #include <fcntl.h>
24 #include <string.h>
25 #include <errno.h>
26 #include <signal.h>
27 #include <sys/wait.h>
28
29 /* This function is intended to rack up both user and system time. */
30 static void
chew_cpu(void)31 chew_cpu (void)
32 {
33 while (1)
34 {
35 static volatile char buf[4096];
36 for (int i = 0; i < 100; ++i)
37 for (size_t j = 0; j < sizeof buf; ++j)
38 buf[j] = 0xaa;
39 int nullfd = open ("/dev/null", O_WRONLY);
40 for (int i = 0; i < 100; ++i)
41 for (size_t j = 0; j < sizeof buf; ++j)
42 buf[j] = 0xbb;
43 write (nullfd, (char *) buf, sizeof buf);
44 close (nullfd);
45 if (getppid () == 1)
46 _exit (2);
47 }
48 }
49
50 static int
do_test(void)51 do_test (void)
52 {
53 int result = 0;
54 clockid_t cl;
55 int e;
56 pid_t dead_child, child;
57
58 /* Fork a child and let it die, to give us a PID known not be valid
59 (assuming PIDs don't wrap around during the test). */
60 {
61 dead_child = fork ();
62 if (dead_child == 0)
63 _exit (0);
64 if (dead_child < 0)
65 {
66 perror ("fork");
67 return 1;
68 }
69 int x;
70 if (wait (&x) != dead_child)
71 {
72 perror ("wait");
73 return 2;
74 }
75 }
76
77 /* POSIX says we should get ESRCH for this. */
78 e = clock_getcpuclockid (dead_child, &cl);
79 if (e != ENOSYS && e != ESRCH && e != EPERM)
80 {
81 printf ("clock_getcpuclockid on dead PID %d => %s\n",
82 dead_child, strerror (e));
83 result = 1;
84 }
85
86 /* Now give us a live child eating up CPU time. */
87 child = fork ();
88 if (child == 0)
89 {
90 chew_cpu ();
91 _exit (1);
92 }
93 if (child < 0)
94 {
95 perror ("fork");
96 return 1;
97 }
98
99 e = clock_getcpuclockid (child, &cl);
100 if (e == EPERM)
101 {
102 puts ("clock_getcpuclockid does not support other processes");
103 goto done;
104 }
105 if (e != 0)
106 {
107 printf ("clock_getcpuclockid on live PID %d => %s\n",
108 child, strerror (e));
109 result = 1;
110 goto done;
111 }
112
113 const clockid_t child_clock = cl;
114 struct timespec res;
115 if (clock_getres (child_clock, &res) < 0)
116 {
117 printf ("clock_getres on live PID %d clock %lx => %s\n",
118 child, (unsigned long int) child_clock, strerror (errno));
119 result = 1;
120 goto done;
121 }
122 printf ("live PID %d clock %lx resolution %lu.%.9lu\n",
123 child, (unsigned long int) child_clock, res.tv_sec, res.tv_nsec);
124
125 struct timespec before, after;
126 if (clock_gettime (child_clock, &before) < 0)
127 {
128 printf ("clock_gettime on live PID %d clock %lx => %s\n",
129 child, (unsigned long int) child_clock, strerror (errno));
130 result = 1;
131 goto done;
132 }
133 printf ("live PID %d before sleep => %lu.%.9lu\n",
134 child, before.tv_sec, before.tv_nsec);
135
136 struct timespec sleeptime = { .tv_nsec = 500000000 };
137 nanosleep (&sleeptime, NULL);
138
139 if (clock_gettime (child_clock, &after) < 0)
140 {
141 printf ("clock_gettime on live PID %d clock %lx => %s\n",
142 child, (unsigned long int) child_clock, strerror (errno));
143 result = 1;
144 goto done;
145 }
146 printf ("live PID %d after sleep => %lu.%.9lu\n",
147 child, after.tv_sec, after.tv_nsec);
148
149 struct timespec diff = { .tv_sec = after.tv_sec - before.tv_sec,
150 .tv_nsec = after.tv_nsec - before.tv_nsec };
151 if (diff.tv_nsec < 0)
152 {
153 --diff.tv_sec;
154 diff.tv_nsec += 1000000000;
155 }
156 if (diff.tv_sec != 0
157 || diff.tv_nsec > 600000000
158 || diff.tv_nsec < 100000000)
159 {
160 printf ("before - after %lu.%.9lu outside reasonable range\n",
161 diff.tv_sec, diff.tv_nsec);
162 result = 1;
163 }
164
165 sleeptime.tv_nsec = 100000000;
166 e = clock_nanosleep (child_clock, 0, &sleeptime, NULL);
167 if (e == EINVAL || e == ENOTSUP || e == ENOSYS)
168 {
169 printf ("clock_nanosleep not supported for other process clock: %s\n",
170 strerror (e));
171 }
172 else if (e != 0)
173 {
174 printf ("clock_nanosleep on other process clock: %s\n", strerror (e));
175 result = 1;
176 }
177 else
178 {
179 struct timespec afterns;
180 if (clock_gettime (child_clock, &afterns) < 0)
181 {
182 printf ("clock_gettime on live PID %d clock %lx => %s\n",
183 child, (unsigned long int) child_clock, strerror (errno));
184 result = 1;
185 }
186 else
187 {
188 struct timespec d = { .tv_sec = afterns.tv_sec - after.tv_sec,
189 .tv_nsec = afterns.tv_nsec - after.tv_nsec };
190 if (d.tv_nsec < 0)
191 {
192 --d.tv_sec;
193 d.tv_nsec += 1000000000;
194 }
195 if (d.tv_sec > 0
196 || d.tv_nsec < sleeptime.tv_nsec
197 || d.tv_nsec > sleeptime.tv_nsec * 2)
198 {
199 printf ("nanosleep time %lu.%.9lu outside reasonable range\n",
200 d.tv_sec, d.tv_nsec);
201 result = 1;
202 }
203 }
204 }
205
206 if (kill (child, SIGKILL) != 0)
207 {
208 perror ("kill");
209 result = 2;
210 goto done;
211 }
212
213 /* Wait long enough to let the child finish dying. */
214
215 sleeptime.tv_nsec = 200000000;
216 nanosleep (&sleeptime, NULL);
217
218 struct timespec dead;
219 if (clock_gettime (child_clock, &dead) < 0)
220 {
221 printf ("clock_gettime on dead PID %d clock %lx => %s\n",
222 child, (unsigned long int) child_clock, strerror (errno));
223 result = 1;
224 goto done;
225 }
226 printf ("dead PID %d => %lu.%.9lu\n",
227 child, dead.tv_sec, dead.tv_nsec);
228
229 diff.tv_sec = dead.tv_sec - after.tv_sec;
230 diff.tv_nsec = dead.tv_nsec - after.tv_nsec;
231 if (diff.tv_nsec < 0)
232 {
233 --diff.tv_sec;
234 diff.tv_nsec += 1000000000;
235 }
236 if (diff.tv_sec != 0 || diff.tv_nsec > 200000000)
237 {
238 printf ("dead - after %lu.%.9lu outside reasonable range\n",
239 diff.tv_sec, diff.tv_nsec);
240 result = 1;
241 }
242
243 /* Now reap the child and verify that its clock is no longer valid. */
244 {
245 int x;
246 if (waitpid (child, &x, 0) != child)
247 {
248 perror ("waitpid");
249 result = 1;
250 }
251 }
252
253 if (clock_gettime (child_clock, &dead) == 0)
254 {
255 printf ("clock_gettime on reaped PID %d clock %lx => %lu%.9lu\n",
256 child, (unsigned long int) child_clock,
257 dead.tv_sec, dead.tv_nsec);
258 result = 1;
259 }
260 else
261 {
262 if (errno != EINVAL)
263 result = 1;
264 printf ("clock_gettime on reaped PID %d clock %lx => %s\n",
265 child, (unsigned long int) child_clock, strerror (errno));
266 }
267
268 if (clock_getres (child_clock, &dead) == 0)
269 {
270 printf ("clock_getres on reaped PID %d clock %lx => %lu%.9lu\n",
271 child, (unsigned long int) child_clock,
272 dead.tv_sec, dead.tv_nsec);
273 result = 1;
274 }
275 else
276 {
277 if (errno != EINVAL)
278 result = 1;
279 printf ("clock_getres on reaped PID %d clock %lx => %s\n",
280 child, (unsigned long int) child_clock, strerror (errno));
281 }
282
283 return result;
284
285 done:
286 {
287 if (kill (child, SIGKILL) != 0 && errno != ESRCH)
288 {
289 perror ("kill");
290 return 2;
291 }
292 int x;
293 if (waitpid (child, &x, 0) != child && errno != ECHILD)
294 {
295 perror ("waitpid");
296 return 2;
297 }
298 }
299
300 return result;
301 }
302
303
304 #define TIMEOUT 5
305 #define TEST_FUNCTION do_test ()
306 #include "../test-skeleton.c"
307