OPENIB: Fixed error from writing to an uninitialized pipe.

The error was caused by leaving the pipe to the async thread uninitialized, then writing to it regardless of this. 
Fix is to check the existance of the async thread and the pipe to it.

reviewd by miked

cmr=v1.7.5:reviewer=ompi-rm1.7

This commit was SVN r30644.

ompi/mca/btl/openib/connect/btl_openib_connect_udcm.c

@@ -848,26 +848,31 @@ static void udcm_module_destroy_listen_qp (udcm_module_t *m)
 {
     struct ibv_qp_attr attr;
     struct ibv_wc wc;
-    mca_btl_openib_async_cmd_t async_command;
 
     if (NULL == m->listen_qp) {
         return;
     }
 
-    /* Tell the openib async thread to ignore ERR state on the QP
-       we are about to manually set the ERR state on */
-    async_command.a_cmd = OPENIB_ASYNC_IGNORE_QP_ERR;
-    async_command.qp = m->listen_qp;
-    if (write(mca_btl_openib_component.async_pipe[1],
-              &async_command, sizeof(mca_btl_openib_async_cmd_t))<0){
-        BTL_ERROR(("Failed to write to pipe [%d]",errno));
-        return;
-    }
-    /* wait for ok from thread */
-    if (OMPI_SUCCESS !=
-        btl_openib_async_command_done(OPENIB_ASYNC_IGNORE_QP_ERR)) {
-        BTL_ERROR(("Command to openib async thread to ignore QP ERR state failed"));
+#if OPAL_HAVE_THREADS
+    if (mca_btl_openib_component.use_async_event_thread &&
+        -1 != mca_btl_openib_component.async_pipe[1]) {
+        /* Tell the openib async thread to ignore ERR state on the QP
+           we are about to manually set the ERR state on */
+        mca_btl_openib_async_cmd_t async_command;
+        async_command.a_cmd = OPENIB_ASYNC_IGNORE_QP_ERR;
+        async_command.qp = m->listen_qp;
+        if (write(mca_btl_openib_component.async_pipe[1],
+                  &async_command, sizeof(mca_btl_openib_async_cmd_t))<0){
+            BTL_ERROR(("Failed to write to pipe [%d]",errno));
+            return;
+        }
+        /* wait for ok from thread */
+        if (OMPI_SUCCESS !=
+                        btl_openib_async_command_done(OPENIB_ASYNC_IGNORE_QP_ERR)) {
+            BTL_ERROR(("Command to openib async thread to ignore QP ERR state failed"));
+        }
     }
+#endif
 
     do {
         /* Move listen QP into the ERR state to cancel all outstanding