video_output: fix controls and events not processed

This issue is easily reproducible with VDPAU activated, with a 60fps ts file,
see #14199.

With this sample, The video_output Thread is looping in ThreadDisplayPicture
way more often than with other videos. Consequently, vout_ManageWrapper and
ThreadControl are not called enough. As a result, subtitles are processed too
late, the mouse isn't able to hide/unhide, we can be stuck in fullscreen mode,
or second click on video to pop up the menu doesn't work.

To fix this issue: don't loop in ThreadDisplayPicture and don't wait in
vout_control_Pop if a picture was previously displayed.

Fixes #14199
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

src/video_output/control.c

@@ -177,19 +177,16 @@ void vout_control_PushString(vout_control_t *ctrl, int type, const char *string)
 }
 
 int vout_control_Pop(vout_control_t *ctrl, vout_control_cmd_t *cmd,
-                     mtime_t deadline, mtime_t timeout)
+                     mtime_t deadline)
 {
     vlc_mutex_lock(&ctrl->lock);
     if (ctrl->cmd.i_size <= 0) {
         ctrl->is_processing = false;
         vlc_cond_broadcast(&ctrl->wait_acknowledge);
 
-        const mtime_t max_deadline = mdate() + timeout;
-        const mtime_t wait_deadline = deadline <= VLC_TS_INVALID ? max_deadline : __MIN(deadline, max_deadline);
-
         /* Spurious wakeups are perfectly fine */
-        if (ctrl->can_sleep)
-            vlc_cond_timedwait(&ctrl->wait_request, &ctrl->lock, wait_deadline);
+        if (deadline > VLC_TS_INVALID && ctrl->can_sleep)
+            vlc_cond_timedwait(&ctrl->wait_request, &ctrl->lock, deadline);
     }
 
     bool has_cmd;

src/video_output/control.h

@@ -130,7 +130,7 @@ void vout_control_PushString(vout_control_t *, int type, const char *string);
 void vout_control_Wake(vout_control_t *);
 
 /* control inside of the vout thread */
-int vout_control_Pop(vout_control_t *, vout_control_cmd_t *, mtime_t deadline, mtime_t timeout);
+int vout_control_Pop(vout_control_t *, vout_control_cmd_t *, mtime_t deadline);
 void vout_control_Dead(vout_control_t *);
 
 #endif

src/video_output/video_output.c

@@ -1558,16 +1558,23 @@ static void *Thread(void *object)
     };
 
     mtime_t deadline = VLC_TS_INVALID;
+    bool wait = false;
     for (;;) {
         vout_control_cmd_t cmd;
-        /* FIXME remove thoses ugly timeouts */
-        while (!vout_control_Pop(&sys->control, &cmd, deadline, 100000))
+
+        if (wait)
+        {
+            const mtime_t max_deadline = mdate() + 100000;
+            deadline = deadline <= VLC_TS_INVALID ? max_deadline : __MIN(deadline, max_deadline);
+        } else {
+            deadline = VLC_TS_INVALID;
+        }
+        while (!vout_control_Pop(&sys->control, &cmd, deadline))
             if (ThreadControl(vout, cmd))
                 return NULL;
 
         deadline = VLC_TS_INVALID;
-        while (!ThreadDisplayPicture(vout, &deadline))
-            ;
+        wait = ThreadDisplayPicture(vout, &deadline) != VLC_SUCCESS;
 
         const bool picture_interlaced = sys->displayed.is_interlaced;