1 files changed, 106 insertions, 0 deletions
diff --git a/test/pthread/ex7.c b/test/pthread/ex7.c
new file mode 100644
index 0000000..8eeb9a2
--- /dev/null
+++ b/test/pthread/ex7.c
@@ -0,0 +1,106 @@
+/* ex7
+ *
+ * Test case that illustrates a timed wait on a condition variable.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <pthread.h>
+#include <sys/time.h>
+#include <time.h>
+
+/* Our event variable using a condition variable contruct. */
+typedef struct {
+    pthread_mutex_t	mutex;
+    pthread_cond_t	cond;
+    int			flag;
+} event_t;
+
+
+/* Global event to signal main thread the timeout of the child thread. */
+event_t main_event;
+
+
+static void *
+test_thread (void *ms_param)
+{
+    unsigned long status = 0;
+    event_t foo;
+    struct timespec timeout;
+    struct timeval  now;
+    long ms = (long) ms_param;
+
+    /* initialize cond var */
+    pthread_cond_init(&foo.cond, NULL);
+    pthread_mutex_init(&foo.mutex, NULL);
+    foo.flag = 0;
+
+    /* set the time out value */
+    printf("waiting %ld ms ...\n", ms);
+    gettimeofday(&now, NULL);
+    timeout.tv_sec  = now.tv_sec + ms/1000 + (now.tv_usec + (ms%1000)*1000)/1000000;
+    timeout.tv_nsec = ((now.tv_usec + (ms%1000)*1000) % 1000000) * 1000;
+
+    /* Just use this to test the time out. The cond var is never signaled. */
+    pthread_mutex_lock(&foo.mutex);
+    while (foo.flag == 0 && status != ETIMEDOUT) {
+	status = pthread_cond_timedwait(&foo.cond, &foo.mutex, &timeout);
+    }
+    pthread_mutex_unlock(&foo.mutex);
+
+    /* post the main event */
+    pthread_mutex_lock(&main_event.mutex);
+    main_event.flag = 1;
+    pthread_cond_signal(&main_event.cond);
+    pthread_mutex_unlock(&main_event.mutex);
+
+    /* that's it, bye */
+    return (void*) status;
+}
+
+int
+main (void)
+{
+  unsigned long count;
+  struct timespec ts;
+  ts.tv_sec = 0;
+  ts.tv_nsec = 10 * 1000;
+
+  setvbuf (stdout, NULL, _IONBF, 0);
+
+  /* initialize main event cond var */
+  pthread_cond_init(&main_event.cond, NULL);
+  pthread_mutex_init(&main_event.mutex, NULL);
+  main_event.flag = 0;
+
+  for (count = 0; count < 20; ++count)
+  {
+      pthread_t thread;
+      int status;
+
+      /* pass down the milli-second timeout in the void* param */
+      status = pthread_create (&thread, NULL, test_thread, (void*) (count*100));
+      if (status != 0) {
+	  printf ("status = %d, count = %lu: %s\n", status, count,
+		  strerror (errno));
+	  return 1;
+      }
+      else {
+
+	  /* wait for the event posted by the child thread */
+	  pthread_mutex_lock(&main_event.mutex);
+	  while (main_event.flag == 0) {
+	      pthread_cond_wait(&main_event.cond, &main_event.mutex);
+	  }
+	  main_event.flag = 0;
+	  pthread_mutex_unlock(&main_event.mutex);
+
+	  printf ("count = %lu\n", count);
+      }
+
+      nanosleep (&ts, NULL);
+  }
+
+  return 0;
+}