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vncserver: Fix dead lock on re-connect

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`vnc_remove_queue` would waiting for new frame update request forever
even if the connection is lost, the updater thread wouldn't exit.
But the server thread will join updater thread before accept new client
connection, then we can't re-conncet to vnc server.

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
This commit is contained in:
Huang Qi 2022-02-15 15:07:42 +08:00 committed by Xiang Xiao
parent 0169a51220
commit ccc708a142
1 changed files with 20 additions and 3 deletions
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23
drivers/video/vnc/vnc_updater.c
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@ -248,8 +248,8 @@ static void vnc_free_update(FAR struct vnc_session_s *session,
* session - A reference to the VNC session structure.
*
* Returned Value:
* A non-NULL structure pointer should always be returned. This function
* will wait if no structure is available.
* A structure pointer should always be returned. If the return value is
* NULL, that means connection lost, no frame update request anymore.
*
****************************************************************************/
@ -274,7 +274,11 @@ vnc_remove_queue(FAR struct vnc_session_s *session)
rect = (FAR struct vnc_fbupdate_s *)sq_remfirst(&session->updqueue);
vnc_sem_debug(session, "After remove", 0);
DEBUGASSERT(rect != NULL);
if (NULL == rect)
{
goto errout;
}
/* Check if we just removed the whole screen update from the queue */
@ -284,6 +288,7 @@ vnc_remove_queue(FAR struct vnc_session_s *session)
updinfo("Whole screen update: nwhupd=%d\n", session->nwhupd);
}
errout:
sched_unlock();
return rect;
}
@ -369,6 +374,14 @@ static FAR void *vnc_updater(FAR void *arg)
*/
srcrect = vnc_remove_queue(session);
/* If connect lost, exit this updater loop */
if (session->state == VNCSERVER_STOPPING)
{
break;
}
DEBUGASSERT(srcrect != NULL);
updinfo("Dequeued {(%d, %d),(%d, %d)}\n",
@ -493,6 +506,10 @@ int vnc_stop_updater(FAR struct vnc_session_s *session)
session->state = VNCSERVER_STOPPING;
/* Notify updater thread we stopped */
nxsem_post(&session->queuesem);
/* Wait for the thread to comply with our request */
status = pthread_join(session->updater, &result);