/* Test program for process CPU clocks.
Copyright (C) 2004-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <stdint.h>
#include <sys/wait.h>
/* This function is intended to rack up both user and system time. */
static void
chew_cpu (void)
{
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);
if (getppid () == 1)
_exit (2);
}
}
static int
do_test (void)
{
int result = 0;
clockid_t cl;
int e;
pid_t dead_child, child;
/* Fork a child and let it die, to give us a PID known not be valid
(assuming PIDs don't wrap around during the test). */
{
dead_child = fork ();
if (dead_child == 0)
_exit (0);
if (dead_child < 0)
{
perror ("fork");
return 1;
}
int x;
if (wait (&x) != dead_child)
{
perror ("wait");
return 2;
}
}
/* POSIX says we should get ESRCH for this. */
e = clock_getcpuclockid (dead_child, &cl);
if (e != ENOSYS && e != ESRCH && e != EPERM)
{
printf ("clock_getcpuclockid on dead PID %d => %s\n",
dead_child, strerror (e));
result = 1;
}
/* Now give us a live child eating up CPU time. */
child = fork ();
if (child == 0)
{
chew_cpu ();
_exit (1);
}
if (child < 0)
{
perror ("fork");
return 1;
}
e = clock_getcpuclockid (child, &cl);
if (e == EPERM)
{
puts ("clock_getcpuclockid does not support other processes");
goto done;
}
if (e != 0)
{
printf ("clock_getcpuclockid on live PID %d => %s\n",
child, strerror (e));
result = 1;
goto done;
}
const clockid_t child_clock = cl;
struct timespec res;
if (clock_getres (child_clock, &res) < 0)
{
printf ("clock_getres on live PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
result = 1;
goto done;
}
printf ("live PID %d clock %lx resolution %ju.%.9ju\n",
child, (unsigned long int) child_clock,
(uintmax_t) res.tv_sec, (uintmax_t) res.tv_nsec);
struct timespec before, after;
if (clock_gettime (child_clock, &before) < 0)
{
printf ("clock_gettime on live PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
result = 1;
goto done;
}
/* Should be close to 0.0. */
printf ("live PID %d before sleep => %ju.%.9ju\n",
child, (uintmax_t) before.tv_sec, (uintmax_t) before.tv_nsec);
struct timespec sleeptime = { .tv_nsec = 500000000 };
if (nanosleep (&sleeptime, NULL) != 0)
{
perror ("nanosleep");
result = 1;
goto done;
}
if (clock_gettime (child_clock, &after) < 0)
{
printf ("clock_gettime on live PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
result = 1;
goto done;
}
/* Should be close to 0.5. */
printf ("live PID %d after sleep => %ju.%.9ju\n",
child, (uintmax_t) after.tv_sec, (uintmax_t) after.tv_nsec);
struct timespec diff = { .tv_sec = after.tv_sec - before.tv_sec,
.tv_nsec = after.tv_nsec - before.tv_nsec };
if (diff.tv_nsec < 0)
{
--diff.tv_sec;
diff.tv_nsec += 1000000000;
}
if (diff.tv_sec != 0
|| diff.tv_nsec > 600000000
|| diff.tv_nsec < 100000000)
{
printf ("before - after %ju.%.9ju outside reasonable range\n",
(uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec);
result = 1;
}
sleeptime.tv_nsec = 100000000;
e = clock_nanosleep (child_clock, 0, &sleeptime, NULL);
if (e == EINVAL || e == ENOTSUP || e == ENOSYS)
{
printf ("clock_nanosleep not supported for other process clock: %s\n",
strerror (e));
}
else if (e != 0)
{
printf ("clock_nanosleep on other process clock: %s\n", strerror (e));
result = 1;
}
else
{
struct timespec afterns;
if (clock_gettime (child_clock, &afterns) < 0)
{
printf ("clock_gettime on live PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
result = 1;
}
else
{
struct timespec d = { .tv_sec = afterns.tv_sec - after.tv_sec,
.tv_nsec = afterns.tv_nsec - after.tv_nsec };
if (d.tv_nsec < 0)
{
--d.tv_sec;
d.tv_nsec += 1000000000;
}
if (d.tv_sec > 0
|| d.tv_nsec < sleeptime.tv_nsec
|| d.tv_nsec > sleeptime.tv_nsec * 2)
{
printf ("nanosleep time %ju.%.9ju outside reasonable range\n",
(uintmax_t) d.tv_sec, (uintmax_t) d.tv_nsec);
result = 1;
}
}
}
if (kill (child, SIGKILL) != 0)
{
perror ("kill");
result = 2;
goto done;
}
/* Wait long enough to let the child finish dying. */
sleeptime.tv_nsec = 200000000;
if (nanosleep (&sleeptime, NULL) != 0)
{
perror ("nanosleep");
result = 1;
goto done;
}
struct timespec dead;
if (clock_gettime (child_clock, &dead) < 0)
{
printf ("clock_gettime on dead PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
result = 1;
goto done;
}
/* Should be close to 0.6. */
printf ("dead PID %d => %ju.%.9ju\n",
child, (uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
diff.tv_sec = dead.tv_sec - after.tv_sec;
diff.tv_nsec = dead.tv_nsec - after.tv_nsec;
if (diff.tv_nsec < 0)
{
--diff.tv_sec;
diff.tv_nsec += 1000000000;
}
if (diff.tv_sec != 0 || diff.tv_nsec > 200000000)
{
printf ("dead - after %ju.%.9ju outside reasonable range\n",
(uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec);
result = 1;
}
/* Now reap the child and verify that its clock is no longer valid. */
{
int x;
if (waitpid (child, &x, 0) != child)
{
perror ("waitpid");
result = 1;
}
}
if (clock_gettime (child_clock, &dead) == 0)
{
printf ("clock_gettime on reaped PID %d clock %lx => %ju%.9ju\n",
child, (unsigned long int) child_clock,
(uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
result = 1;
}
else
{
if (errno != EINVAL)
result = 1;
printf ("clock_gettime on reaped PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
}
if (clock_getres (child_clock, &dead) == 0)
{
printf ("clock_getres on reaped PID %d clock %lx => %ju%.9ju\n",
child, (unsigned long int) child_clock,
(uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
result = 1;
}
else
{
if (errno != EINVAL)
result = 1;
printf ("clock_getres on reaped PID %d clock %lx => %s\n",
child, (unsigned long int) child_clock, strerror (errno));
}
return result;
done:
{
if (kill (child, SIGKILL) != 0 && errno != ESRCH)
{
perror ("kill");
return 2;
}
int x;
if (waitpid (child, &x, 0) != child && errno != ECHILD)
{
perror ("waitpid");
return 2;
}
}
return result;
}
#define TIMEOUT 5
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"