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-rw-r--r--rt/tst-cputimer3.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/rt/tst-cputimer3.c b/rt/tst-cputimer3.c
new file mode 100644
index 0000000..056766a
--- /dev/null
+++ b/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"