Message ID | 20170504084159.7488.97487.stgit@PASHA-ISP |
---|---|
State | New |
Headers | show |
On 04/05/2017 10:41, Pavel Dovgalyuk wrote: > From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> > > Asynchronous events saved at checkpoints may invoke > callbacks when processed. These callbacks may also generate/read > new events (e.g. clock reads). Therefore event processing flag must be > reset before callback invocation. > > Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> > --- > replay/replay-events.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/replay/replay-events.c b/replay/replay-events.c > index 94a6dcccfc..768b505f3d 100644 > --- a/replay/replay-events.c > +++ b/replay/replay-events.c > @@ -295,13 +295,13 @@ void replay_read_events(int checkpoint) > if (!event) { > break; > } > + replay_finish_event(); > + read_event_kind = -1; > replay_mutex_unlock(); > replay_run_event(event); > replay_mutex_lock(); > > g_free(event); > - replay_finish_event(); > - read_event_kind = -1; While at it, g_free can be moved outside the lock. Also, replay_flush_events and replay_save_events are leaving the event in events_list while releasing the lock, and only doing QTAILQ_REMOVE after taking it back. This can cause events to be processed twice. I think it is worth fixing all of these. Paolo > } > } > >
> From: Paolo Bonzini [mailto:pbonzini@redhat.com] > On 04/05/2017 10:41, Pavel Dovgalyuk wrote: > > From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> > > > > Asynchronous events saved at checkpoints may invoke > > callbacks when processed. These callbacks may also generate/read > > new events (e.g. clock reads). Therefore event processing flag must be > > reset before callback invocation. > > > > Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> > > --- > > replay/replay-events.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/replay/replay-events.c b/replay/replay-events.c > > index 94a6dcccfc..768b505f3d 100644 > > --- a/replay/replay-events.c > > +++ b/replay/replay-events.c > > @@ -295,13 +295,13 @@ void replay_read_events(int checkpoint) > > if (!event) { > > break; > > } > > + replay_finish_event(); > > + read_event_kind = -1; > > replay_mutex_unlock(); > > replay_run_event(event); > > replay_mutex_lock(); > > > > g_free(event); > > - replay_finish_event(); > > - read_event_kind = -1; > > While at it, g_free can be moved outside the lock. There is no difference where to free the memory. The only reason for unlocking and locking again is that replay_run_event may try to read more data from the log. > Also, replay_flush_events and replay_save_events are leaving the event > in events_list while releasing the lock, and only doing QTAILQ_REMOVE > after taking it back. This can cause events to be processed twice. How this could happen? If something will try to call replay_save_events again, while in replay_save_events, then we'll have an infinite loop and notice it. But it couldn't, because saving only occurs at checkpoints and there are no recursive ones. Pavel Dovgalyuk
diff --git a/replay/replay-events.c b/replay/replay-events.c index 94a6dcccfc..768b505f3d 100644 --- a/replay/replay-events.c +++ b/replay/replay-events.c @@ -295,13 +295,13 @@ void replay_read_events(int checkpoint) if (!event) { break; } + replay_finish_event(); + read_event_kind = -1; replay_mutex_unlock(); replay_run_event(event); replay_mutex_lock(); g_free(event); - replay_finish_event(); - read_event_kind = -1; } }