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author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/rt/tst-cputimer3.c | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.gz glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.xz glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.zip |
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/rt/tst-cputimer3.c')
-rw-r--r-- | REORG.TODO/rt/tst-cputimer3.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/REORG.TODO/rt/tst-cputimer3.c b/REORG.TODO/rt/tst-cputimer3.c new file mode 100644 index 0000000000..056766a377 --- /dev/null +++ b/REORG.TODO/rt/tst-cputimer3.c @@ -0,0 +1,130 @@ +/* Tests for POSIX timer implementation using another process's 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 <signal.h> +#include <sys/wait.h> + +static clockid_t child_clock; + +#define TEST_CLOCK child_clock +#define TEST_CLOCK_MISSING(clock) \ + (setup_test () ? "other-process CPU clock timer support" : NULL) + +/* 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 pid_t child; +static void +cleanup_child (void) +{ + if (child <= 0) + return; + if (kill (child, SIGKILL) < 0 && errno != ESRCH) + printf ("cannot kill child %d: %m\n", child); + else + { + int status; + errno = 0; + if (waitpid (child, &status, 0) != child) + printf ("waitpid %d: %m\n", child); + } +} +#define CLEANUP_HANDLER cleanup_child () + +static int +setup_test (void) +{ + /* Test timers on a process CPU clock by having a child process eating + CPU. First make sure we can make such timers at all. */ + + int pipefd[2]; + if (pipe (pipefd) < 0) + { + printf ("pipe: %m\n"); + exit (1); + } + + child = fork (); + + if (child == 0) + { + char c; + close (pipefd[1]); + if (read (pipefd[0], &c, 1) == 1) + chew_cpu (); + _exit (1); + } + + if (child < 0) + { + printf ("fork: %m\n"); + exit (1); + } + + atexit (&cleanup_child); + + close (pipefd[0]); + + int e = clock_getcpuclockid (child, &child_clock); + if (e == EPERM) + { + puts ("clock_getcpuclockid does not support other processes"); + return 1; + } + if (e != 0) + { + printf ("clock_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); + + /* Get the child started chewing. */ + if (write (pipefd[1], "x", 1) != 1) + { + printf ("write to pipe: %m\n"); + return 1; + } + close (pipefd[1]); + + return 0; +} + +#else +# define TEST_CLOCK_MISSING(clock) "process clocks" +#endif + +#include "tst-timer4.c" |