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, 5 insertions, 0 deletions

diff --git a/src/core/platform.h b/src/core/platform.h
index d2409e5b..2f5b5c17 100644
--- a/src/core/platform.h
+++ b/src/core/platform.h
@@ -293,6 +293,7 @@ extern void nni_tcp_dialer_fini(nni_tcp_dialer *);
 // Further operations on it should return NNG_ECLOSED.
 // Any in-progress connection will be aborted.
 extern void nni_tcp_dialer_close(nni_tcp_dialer *);
+extern void nni_tcp_dialer_stop(nni_tcp_dialer *);
 
 // nni_tcp_dial attempts to create an outgoing connection,
 // asynchronously, to the address in the aio. On success, the first (and only)
@@ -318,6 +319,10 @@ extern void nni_tcp_listener_fini(nni_tcp_listener *);
 // any bound socket, and further operations will result in NNG_ECLOSED.
 extern void nni_tcp_listener_close(nni_tcp_listener *);
 
+// nni_tcp_listener_stop is close + waits for any operations to stop,
+// so there won't be any further accepts after this.
+extern void nni_tcp_listener_stop(nni_tcp_listener *);
+
 // nni_tcp_listener_listen creates the socket in listening mode, bound
 // to the specified address.
 extern int nni_tcp_listener_listen(nni_tcp_listener *, const nni_sockaddr *);