diff options
Diffstat (limited to 'time/tst-cpuclock1.c')
| -rw-r--r-- | time/tst-cpuclock1.c | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/time/tst-cpuclock1.c b/time/tst-cpuclock1.c new file mode 100644 index 0000000000..e3f23aa307 --- /dev/null +++ b/time/tst-cpuclock1.c @@ -0,0 +1,320 @@ +/* Test program for process CPU clocks. + Copyright (C) 2004-2019 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 TEST_FUNCTION do_test () +#include "../test-skeleton.c" |