[virt-tools-list] [virt-viewer v2 08/13] events: protect 'handles' and 'timeouts' against concurrent accesses

[Fabiano Fidêncio]

Timeout and watch deletion is done from an idle callback. However,
we cannot assume that all libvirt event calls (the callbacks passed
to virEventRegisterImpl) will be done from the mainloop thread. It's
thus possible that a libvirt event call will run a thread while
one of the idle deletion callbacks runs.
Given that the 'handles' and 'timeouts' arrays are shared among all
threads, we need to make sure we hold the 'eventlock' mutex before
modifying them.

Based on commit 924178f6b35735458b37d30303fe7bc753dde0b1 from
libvirt-glib.
Original author: Christophe Fergeau <cfergeau at redhat.com>

Related to: rhbz#1243228
---
 src/virt-viewer-events.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/virt-viewer-events.c b/src/virt-viewer-events.c
index 3d05502..65db605 100644
--- a/src/virt-viewer-events.c
+++ b/src/virt-viewer-events.c
@@ -203,10 +203,15 @@ virt_viewer_events_cleanup_handle(gpointer user_data)
     g_debug("Cleanup of handle %p", data);
     g_return_val_if_fail(data != NULL, FALSE);
 
+    g_mutex_lock(eventlock);
+
     if (data->ff)
         (data->ff)(data->opaque);
 
     g_ptr_array_remove_fast(handles, data);
+
+    g_mutex_unlock(eventlock);
+
     return FALSE;
 }
 
@@ -371,10 +376,15 @@ virt_viewer_events_cleanup_timeout(gpointer user_data)
     g_debug("Cleanup of timeout %p", data);
     g_return_val_if_fail(data != NULL, FALSE);
 
+    g_mutex_lock(eventlock);
+
     if (data->ff)
         (data->ff)(data->opaque);
 
     g_ptr_array_remove_fast(timeouts, data);
+
+    g_mutex_unlock(eventlock);
+
     return FALSE;
 }
 
-- 
2.4.4