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"