1 files changed, 68 insertions, 0 deletions
diff --git a/rt/tst-cputimer1.c b/rt/tst-cputimer1.c
new file mode 100644
index 0000000000..8f5dd76cf2
--- /dev/null
+++ b/rt/tst-cputimer1.c
@@ -0,0 +1,68 @@
+/* Tests for POSIX timer implementation using process CPU clock.  */
+
+#include <unistd.h>
+
+#if _POSIX_THREADS && defined _POSIX_CPUTIME
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <pthread.h>
+
+#define TEST_CLOCK CLOCK_PROCESS_CPUTIME_ID
+#define TEST_CLOCK_MISSING(clock) \
+  (setup_test () ? "process CPU clock timer support" : NULL)
+
+/* This function is intended to rack up both user and system time.  */
+static void *
+chew_cpu (void *arg)
+{
+  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);
+    }
+
+  return NULL;
+}
+
+static int
+setup_test (void)
+{
+  /* Test timers on our own process CPU clock by having a worker thread
+     eating CPU.  First make sure we can make such timers at all.  */
+
+  timer_t t;
+  if (timer_create (TEST_CLOCK, NULL, &t) != 0)
+    {
+      printf ("timer_create: %m\n");
+      return 1;
+    }
+  timer_delete (t);
+
+  pthread_t th;
+  int e = pthread_create (&th, NULL, chew_cpu, NULL);
+  if (e != 0)
+    {
+      printf ("pthread_create: %s\n", strerror (e));
+      exit (1);
+    }
+
+  return 0;
+}
+
+#else
+# define TEST_CLOCK_MISSING(clock) "process clocks"
+#endif
+
+#include "tst-timer4.c"