glibc/rt/tst-cputimer2.c

84 lines
1.8 KiB
C

/* Tests for POSIX timer implementation using thread CPU clock. */
#include <unistd.h>
#if _POSIX_THREADS && defined _POSIX_CPUTIME
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <pthread.h>
static clockid_t worker_thread_clock;
#define TEST_CLOCK worker_thread_clock
#define TEST_CLOCK_MISSING(clock) \
(setup_test () ? "thread CPU clock timer support" : NULL)
/* This function is intended to rack up both user and system time. */
static void *
chew_cpu (void *arg)
{
while (1)
{
static volatile char buf[4096];
for (int i = 0; i < 100; ++i)
for (size_t j = 0; j < sizeof buf; ++j)
buf[j] = 0xaa;
int nullfd = open ("/dev/null", O_WRONLY);
for (int i = 0; i < 100; ++i)
for (size_t j = 0; j < sizeof buf; ++j)
buf[j] = 0xbb;
write (nullfd, (char *) buf, sizeof buf);
close (nullfd);
}
return NULL;
}
static int
setup_test (void)
{
/* Test timers on a thread CPU clock by having a worker thread eating
CPU. First make sure we can make such timers at all. */
pthread_t th;
int e = pthread_create (&th, NULL, chew_cpu, NULL);
if (e != 0)
{
printf ("pthread_create: %s\n", strerror (e));
exit (1);
}
e = pthread_getcpuclockid (th, &worker_thread_clock);
if (e == EPERM || e == ENOENT || e == ENOTSUP)
{
puts ("pthread_getcpuclockid does not support other threads");
return 1;
}
if (e != 0)
{
printf ("pthread_getcpuclockid: %s\n", strerror (e));
exit (1);
}
timer_t t;
if (timer_create (TEST_CLOCK, NULL, &t) != 0)
{
printf ("timer_create: %m\n");
return 1;
}
timer_delete (t);
return 0;
}
#else
# define TEST_CLOCK_MISSING(clock) "process clocks"
#endif
#include "tst-timer4.c"