+ callback->cb_fn = cb;
+ callback->cb_arg = cb_arg;
+ callback->pending_delete = 0;
+ callback->ucb_fn = NULL;
+
+ if (src == NULL) {
+ src = calloc(1, sizeof(*src));
+ if (src == NULL) {
+ RTE_LOG(ERR, EAL, "Can not allocate memory\n");
+ ret = -ENOMEM;
+ goto fail;
+ } else {
+ src->intr_handle = *intr_handle;
+ TAILQ_INIT(&src->callbacks);
+ TAILQ_INSERT_TAIL(&intr_sources, src, next);
+ }
+ }
+
+ /* we had no interrupts for this */
+ if (TAILQ_EMPTY(&src->callbacks))
+ add_event = 1;
+
+ TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);