streams: add explicit stop functions

This allows us to explicitly stop streams, dialers, and listeners,
before we start tearing down things. This hopefully will be useful
in resolving use-after-free bugs in http, tls, and websockets.

The new functions are not yet documented, but they are
nng_stream_stop, nng_stream_dialer_stop, and nng_stream_listener_stop.
They should be called after close, and before free.  The close
functions now close without blocking, but the stop function is
allowed to block.

1 files changed, 6 insertions, 1 deletions

diff --git a/demo/stream/stream.c b/demo/stream/stream.c
index c6cc9b23..5a4995e6 100644
--- a/demo/stream/stream.c
+++ b/demo/stream/stream.c
@@ -55,7 +55,7 @@ int
 client(const char *url)
 {
 	nng_stream_dialer *dialer;
-	nng_aio *          aio;
+	nng_aio           *aio;
 	nng_iov            iov;
 	int                rv;
 
@@ -102,6 +102,11 @@ client(const char *url)
 
 	// Send ELCOSE to send/recv associated wit this stream
 	free(iov.iov_buf);
+
+	// stop everything before freeing
+	nng_stream_stop(c1);
+	nng_stream_dialer_stop(dialer);
+
 	nng_stream_free(c1);
 	nng_aio_free(aio);
 	nng_stream_dialer_free(dialer);