fixes #419 want to nni_aio_stop without blocking (#428)

* fixes #419 want to nni_aio_stop without blocking

This actually introduces an nni_aio_close() API that causes
nni_aio_begin to return NNG_ECLOSED, while scheduling a callback
on the AIO to do an NNG_ECLOSED as well.  This should be called
in non-blocking close() contexts instead of nni_aio_stop(), and
the cases where we call nni_aio_fini() multiple times are updated
updated to add nni_aio_stop() calls on all "interlinked" aios before
finalizing them.

Furthermore, we call nni_aio_close() as soon as practical in the
close path.  This closes an annoying race condition where the
callback from a lower subsystem could wind up rescheduling an
operation that we wanted to abort.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/supplemental/websocket/websocket.c b/src/supplemental/websocket/websocket.c
index 9a3f5519..6d4d3c13 100644
--- a/src/supplemental/websocket/websocket.c
+++ b/src/supplemental/websocket/websocket.c
@@ -407,14 +407,15 @@ ws_close_cb(void *arg)
 	nni_ws *ws = arg;
 	ws_msg *wm;
 
+	nni_aio_close(ws->txaio);
+	nni_aio_close(ws->rxaio);
+	nni_aio_close(ws->httpaio);
+
 	// Either we sent a close frame, or we didn't.  Either way,
 	// we are done, and its time to abort everything else.
 	nni_mtx_lock(&ws->mtx);
 
 	nni_http_conn_close(ws->http);
-	nni_aio_abort(ws->txaio, NNG_ECLOSED);
-	nni_aio_abort(ws->rxaio, NNG_ECLOSED);
-	nni_aio_abort(ws->httpaio, NNG_ECLOSED);
 
 	// This list (receive) should be empty.
 	while ((wm = nni_list_first(&ws->rxmsgs)) != NULL) {
@@ -464,8 +465,8 @@ ws_close(nni_ws *ws, uint16_t code)
 	// pending connect request.
 	if (!ws->closed) {
 		// ABORT connection negotiation.
-		nni_aio_abort(ws->connaio, NNG_ECLOSED);
-		nni_aio_abort(ws->httpaio, NNG_ECLOSED);
+		nni_aio_close(ws->connaio);
+		nni_aio_close(ws->httpaio);
 		ws_send_close(ws, code);
 	}