BUG/MEDIUM: h1: Make sure we subscribe before going into idle list.
In h1_detach(), make sure we subscribe before we call
srv_add_to_idle_list(), not after. As soon as srv_add_to_idle_list() is
called, and it is put in an idle list, another thread can take it, and
we're no longer allowed to subscribe.
This fixes a race condition when another thread grabs a connection as soon
as it is put, the original owner would subscribe, and thus the new thread
would fail to do so, and to activate polling.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index f4cf0ff..fee645b 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -2466,13 +2466,13 @@
if (!(h1c->conn->flags & CO_FL_PRIVATE)) {
if (h1c->conn->owner == sess)
h1c->conn->owner = NULL;
+ h1c->conn->xprt->subscribe(h1c->conn, h1c->conn->xprt_ctx, SUB_RETRY_RECV, &h1c->wait_event);
if (!srv_add_to_idle_list(objt_server(h1c->conn->target), h1c->conn, is_not_first)) {
/* The server doesn't want it, let's kill the connection right away */
h1c->conn->mux->destroy(h1c);
TRACE_DEVEL("outgoing connection killed", H1_EV_STRM_END|H1_EV_H1C_END);
goto end;
}
- h1c->conn->xprt->subscribe(h1c->conn, h1c->conn->xprt_ctx, SUB_RETRY_RECV, &h1c->wait_event);
return;
}
}