On Mon, Oct 29, 2018 at 04:57:32PM +0400, Marc-André Lureau wrote:
> Add a monitor_destroyed global to check if monitor_cleanup() has been
> already called. In this case, don't insert the new monitor in the
> list, but free it instead.
Pure question: how to trigger the condition when doing monitor
cleanups?
I can understand the problem to be fixed in the follow-up patch, but I
don't know whether it's that helpful to have this patch though,
especially considering that we're reaching softfreeze.
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> monitor.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index fffeb27ef9..7fe89daa87 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -263,10 +263,11 @@ typedef struct QMPRequest QMPRequest;
> /* QMP checker flags */
> #define QMP_ACCEPT_UNKNOWNS 1
>
> -/* Protects mon_list, monitor_qapi_event_state. */
> +/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed. */
> static QemuMutex monitor_lock;
> static GHashTable *monitor_qapi_event_state;
> static QTAILQ_HEAD(mon_list, Monitor) mon_list;
> +static bool monitor_destroyed;
>
> /* Protects mon_fdsets */
> static QemuMutex mon_fdsets_lock;
> @@ -4536,8 +4537,16 @@ void error_vprintf_unless_qmp(const char *fmt, va_list
> ap)
> static void monitor_list_append(Monitor *mon)
> {
> qemu_mutex_lock(&monitor_lock);
> - QTAILQ_INSERT_HEAD(&mon_list, mon, entry);
> + if (!monitor_destroyed) {
> + QTAILQ_INSERT_HEAD(&mon_list, mon, entry);
> + mon = NULL;
> + }
> qemu_mutex_unlock(&monitor_lock);
> +
> + if (mon) {
> + monitor_data_destroy(mon);
> + g_free(mon);
> + }
> }
>
> static void monitor_qmp_setup_handlers_bh(void *opaque)
> @@ -4631,6 +4640,7 @@ void monitor_cleanup(void)
>
> /* Flush output buffers and destroy monitors */
> qemu_mutex_lock(&monitor_lock);
> + monitor_destroyed = true;
> QTAILQ_FOREACH_SAFE(mon, &mon_list, entry, next) {
> QTAILQ_REMOVE(&mon_list, mon, entry);
> monitor_flush(mon);
> --
> 2.19.0.271.gfe8321ec05
>
Regards,
--
Peter Xu
