1/* Tests for POSIX timer implementation using thread CPU clock. */
2
3#include <unistd.h>
4
5#if _POSIX_THREADS && defined _POSIX_CPUTIME
6
7#include <errno.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11#include <fcntl.h>
12#include <time.h>
13#include <pthread.h>
14
15#include <support/xunistd.h>
16
17static clockid_t worker_thread_clock;
18
19#define TEST_CLOCK worker_thread_clock
20#define TEST_CLOCK_MISSING(clock) \
21 (setup_test () ? "thread CPU clock timer support" : NULL)
22
23/* This function is intended to rack up both user and system time. */
24static void *
25chew_cpu (void *arg)
26{
27 while (1)
28 {
29 static volatile char buf[4096];
30 for (int i = 0; i < 100; ++i)
31 for (size_t j = 0; j < sizeof buf; ++j)
32 buf[j] = 0xaa;
33 int nullfd = open (file: "/dev/null", O_WRONLY);
34 for (int i = 0; i < 100; ++i)
35 for (size_t j = 0; j < sizeof buf; ++j)
36 buf[j] = 0xbb;
37 xwrite (nullfd, (char *) buf, sizeof buf);
38 close (fd: nullfd);
39 }
40
41 return NULL;
42}
43
44static int
45setup_test (void)
46{
47 /* Test timers on a thread CPU clock by having a worker thread eating
48 CPU. First make sure we can make such timers at all. */
49
50 pthread_t th;
51 int e = pthread_create (newthread: &th, NULL, start_routine: chew_cpu, NULL);
52 if (e != 0)
53 {
54 printf (format: "pthread_create: %s\n", strerror (errnum: e));
55 exit (1);
56 }
57
58 e = pthread_getcpuclockid (thread_id: th, clock_id: &worker_thread_clock);
59 if (e == EPERM || e == ENOENT || e == ENOTSUP)
60 {
61 puts (s: "pthread_getcpuclockid does not support other threads");
62 return 1;
63 }
64 if (e != 0)
65 {
66 printf (format: "pthread_getcpuclockid: %s\n", strerror (errnum: e));
67 exit (1);
68 }
69
70 timer_t t;
71 if (timer_create (TEST_CLOCK, NULL, timerid: &t) != 0)
72 {
73 printf (format: "timer_create: %m\n");
74 return 1;
75 }
76 timer_delete (timerid: t);
77
78 return 0;
79}
80
81#else
82# define TEST_CLOCK_MISSING(clock) "process clocks"
83#endif
84
85#include "tst-timer4.c"
86

source code of glibc/rt/tst-cputimer2.c