[PATCH 1/1] winegstreamer: Pause streaming threads when seeking.

[Zhiyi Zhang]

From: Zhiyi Zhang

The streaming threads and GST_Seeking_SetPositions() contend for the same flushing locks.
GST_Seeking_SetPositions() needs to acquire all the flushing locks before doing the actual
stream seeking, having the streaming threads fighting for the same locks will make
GST_Seeking_SetPositions() wait for a unusually long time.

This reduces PowerPoint 2016 video seeking time from ~5s to almost an instant and fixes a regression
for Fallout 3.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53403
---
 dlls/winegstreamer/quartz_parser.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/dlls/winegstreamer/quartz_parser.c b/dlls/winegstreamer/quartz_parser.c
index 9369b529642..3f6b4e11385 100644
--- a/dlls/winegstreamer/quartz_parser.c
+++ b/dlls/winegstreamer/quartz_parser.c
@@ -84,6 +84,11 @@ struct parser_source
     bool need_segment;

bool eos;
+
+    /* When is_seeking is true, the code is in GST_Seeking_SetPositions() and is trying to change
+     * positions. In this case, pause the streaming thread until seeking is completed. Otherwise,
+     * GST_Seeking_SetPositions() may take a long time acquiring all the flushing locks. */
+    bool is_seeking;
 };

static inline struct parser *impl_from_strmbase_filter(struct strmbase_filter *iface)
@@ -929,6 +934,9 @@ static DWORD CALLBACK stream_thread(void *arg)
     {
         struct wg_parser_buffer buffer;

+        while (pin->is_seeking)
+            Sleep(1);
+
         EnterCriticalSection(&pin->flushing_cs);

if (pin->eos)
@@ -1462,7 +1470,10 @@ static HRESULT WINAPI GST_Seeking_SetPositions(IMediaSeeking *iface,
         struct parser_source *flush_pin = filter->sources[i];

if (flush_pin->pin.pin.peer)
+        {
+            flush_pin->is_seeking = true;
             EnterCriticalSection(&flush_pin->flushing_cs);
+        }
     }

SourceSeekingImpl_SetPositions(iface, current, current_flags, stop, stop_flags);
@@ -1494,6 +1505,7 @@ static HRESULT WINAPI GST_Seeking_SetPositions(IMediaSeeking *iface,

if (flush_pin->pin.pin.peer)
         {
+            flush_pin->is_seeking = false;
             LeaveCriticalSection(&flush_pin->flushing_cs);
             WakeConditionVariable(&flush_pin->eos_cv);
         }