run timer callbacks on progress pool if necessary

examples/sleep.c

@@ -100,9 +100,10 @@ int main(int argc, char **argv)
     }
 
     /* actually start margo */
-    /* use a single pool for progress, sleeper, and handler threads */
+    /* use a single pool for progress and sleeper threads */
+    /* NOTE: we don't use RPC handlers, so no need for an RPC pool */
     /***************************************/
-    mid = margo_init(pool, pool, hg_context, hg_class);
+    mid = margo_init(pool, ABT_POOL_NULL, hg_context, hg_class);
     for(i=0; i<4; i++)
     {
         t_ids[i] = i;

src/margo-timer.c

@@ -161,9 +161,16 @@ void margo_check_timers(
 
         /* schedule callback on the handler pool */
         handler_pool = margo_get_handler_pool(mid);
-        ret = ABT_thread_create(*handler_pool, cur->cb_fn, cur->cb_dat,
-            ABT_THREAD_ATTR_NULL, NULL);
-        assert(ret == ABT_SUCCESS);
+        if(*handler_pool != ABT_POOL_NULL)
+        {
+            ret = ABT_thread_create(*handler_pool, cur->cb_fn, cur->cb_dat,
+                ABT_THREAD_ATTR_NULL, NULL);
+            assert(ret == ABT_SUCCESS);
+        }
+        else
+        {
+            cur->cb_fn(cur->cb_dat);
+        }
     }
     ABT_mutex_unlock(timer_inst->mutex);