/* Tests for POSIX timer implementation using process CPU clock.  */

#include <unistd.h>

#if _POSIX_THREADS && defined _POSIX_CPUTIME

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <fcntl.h>

#include <time.h>

#include <pthread.h>

#define TEST_CLOCK CLOCK_PROCESS_CPUTIME_ID

#define TEST_CLOCK_MISSING(clock) \

  (setup_test () ? "process 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 our own process CPU clock by having a worker thread

     eating CPU.  First make sure we can make such timers at all.  */

  timer_t t;

  if (timer_create (TEST_CLOCK, NULL, &t) != 0)

    {

      printf ("timer_create: %m\n");

      return 1;

    }

  timer_delete (t);

  pthread_t th;

  int e = pthread_create (&th, NULL, chew_cpu, NULL);

  if (e != 0)

    {

      printf ("pthread_create: %s\n", strerror (e));

      exit (1);

    }

  return 0;

}

#else

# define TEST_CLOCK_MISSING(clock) "process clocks"

#endif

#include "tst-timer4.c"