Ensure that the progress thread tracker properly cleans up the blocking event, if set. Also, use the blocking event to help wake up the progress thread for quick shutdown as some threads can be blocked in a long-running call to select.

This commit was SVN r32141.

opal/runtime/opal_progress_threads.c

@@ -67,7 +67,12 @@ static opal_list_t tracking;
 static bool inited = false;
 static void wakeup(int fd, short args, void *cbdata)
 {
-    opal_output(0, "progress:wakeup invoked");
+    opal_progress_tracker_t *trk = (opal_progress_tracker_t*)cbdata;
+
+    /* if this event fired, then the blocker event will
+     * be deleted from the event base by libevent, so flag
+     * it so we don't try to delete it again */
+    trk->block_active = false;
 }
 
 
@@ -101,7 +106,7 @@ opal_event_base_t *opal_start_progress_thread(char *name,
             OBJ_RELEASE(trk);
             return NULL;
         }
-        opal_event_set(trk->ev_base, &trk->block, trk->pipe[0], OPAL_EV_READ, wakeup, NULL);
+        opal_event_set(trk->ev_base, &trk->block, trk->pipe[0], OPAL_EV_READ, wakeup, trk);
         opal_event_add(&trk->block, 0);
         trk->block_active = true;
     }
@@ -127,6 +132,7 @@ opal_event_base_t *opal_start_progress_thread(char *name,
 void opal_stop_progress_thread(char *name, bool cleanup)
 {
     opal_progress_tracker_t *trk;
+    int i;
 
     if (!inited) {
         /* nothing we can do */
@@ -136,6 +142,13 @@ void opal_stop_progress_thread(char *name, bool cleanup)
     /* find the specified engine */
     OPAL_LIST_FOREACH(trk, &tracking, opal_progress_tracker_t) {
         if (0 == strcmp(name, trk->name)) {
+            /* if present, use the block to break it loose just in
+             * case the thread is blocking in a call to select for
+             * a long time */
+            if (trk->block_active) {
+                i=1;
+                write(trk->pipe[1], &i, sizeof(int));
+            }
             /* break the event loop */
             opal_event_base_loopbreak(trk->ev_base);
             /* wait for thread to exit */
@@ -167,6 +180,12 @@ int opal_restart_progress_thread(char *name)
                 OPAL_ERROR_LOG(OPAL_ERR_NOT_SUPPORTED);
                 return OPAL_ERR_NOT_SUPPORTED;
             }
+            /* ensure the block is set, if requested */
+            if (0 <= trk->pipe[0] && !trk->block_active) {
+                opal_event_add(&trk->block, 0);
+                trk->block_active = true;
+            }
+            /* start the thread again */
             if (OPAL_SUCCESS != (rc = opal_thread_start(&trk->engine))) {
                 OPAL_ERROR_LOG(rc);
                 return rc;