osc_ucx: fix hang/timeout in component finalize

Add barrier to make sure all endpoints are destroyed before destroying
the worker.

Signed-off-by: Yossi Itigin <yosefe@mellanox.com>

ompi/mca/osc/ucx/osc_ucx_component.c

@@ -127,6 +127,14 @@ static int component_init(bool enable_progress_threads, bool enable_mpi_threads)
     return OMPI_SUCCESS;
 }
 
+static void component_world_barrier(void)
+{
+    ompi_communicator_t *comm = &ompi_mpi_comm_world.comm;
+    opal_progress_register(progress_callback);
+    comm->c_coll->coll_barrier(comm, comm->c_coll->coll_barrier_module);
+    opal_progress_unregister(progress_callback);
+}
+
 static int component_finalize(void) {
     int i;
     for (i = 0; i < ompi_proc_world_size(); i++) {
@@ -136,7 +144,9 @@ static int component_finalize(void) {
         }
     }
 
+    assert(mca_osc_ucx_component.num_modules == 0);
     if (mca_osc_ucx_component.ucp_worker != NULL) {
+        component_world_barrier();
         ucp_worker_destroy(mca_osc_ucx_component.ucp_worker);
     }