rpc: avoid leak of GSource in use for interrupting main loop

We never release the reference on the GSource created for
interrupting the main loop, nor do we remove it from the
main context if our thread is woken up prior to the wakeup
callback firing.

This can result in a leak of GSource objects, along with an
ever growing list of GSources attached to the main context,
which will gradually slow down execution of the loop, as
several operations are O(N) for the number of attached GSource
objects.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c
index 147b0d661a32d92397eba43523721534d91486ea..6d424eb5990a5b3c5a32060dfe19c532fb489b17 100644 (file)
--- a/src/rpc/virnetclient.c
+++ b/src/rpc/virnetclient.c
@@ -1946,7 +1946,7 @@ static int virNetClientIO(virNetClient *client,
     /* Check to see if another thread is dispatching */
     if (client->haveTheBuck) {
         /* Force other thread to wakeup from poll */
-        GSource *wakeup = g_idle_source_new();
+        g_autoptr(GSource) wakeup = g_idle_source_new();
         g_source_set_callback(wakeup, virNetClientIOWakeup, client->eventLoop, NULL);
         g_source_attach(wakeup, client->eventCtx);
 
@@ -1968,6 +1968,7 @@ static int virNetClientIO(virNetClient *client,
             return -1;
         }
 
+        g_source_destroy(wakeup);
         VIR_DEBUG("Woken up from sleep head=%p call=%p",
                   client->waitDispatch, thiscall);
         /* Three reasons we can be woken up