[PATCH v4 3/5] winegstreamer: Synchronize access to the media source from callbacks.

[Giovanni Mascellani]

From: Giovanni Mascellani

---
 dlls/winegstreamer/media_source.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/dlls/winegstreamer/media_source.c b/dlls/winegstreamer/media_source.c
index fade993ca78..5fbc09e19ea 100644
--- a/dlls/winegstreamer/media_source.c
+++ b/dlls/winegstreamer/media_source.c
@@ -533,10 +533,20 @@ static void wait_on_sample(struct media_stream *stream, IUnknown *token)
     struct media_source *source = stream->parent_source;
     PROPVARIANT empty_var = {.vt = VT_EMPTY};
     struct wg_parser_buffer buffer;
+    bool res;

TRACE("%p, %p\n", stream, token);

-    if (wg_parser_stream_get_buffer(source->wg_parser, stream->wg_stream, &buffer))
+    LeaveCriticalSection(&source->cs);
+    res = wg_parser_stream_get_buffer(source->wg_parser, stream->wg_stream, &buffer);
+    EnterCriticalSection(&source->cs);
+
+    /* If the media source has been shut down during the wait, then
+     * resources have been released, so don't touch anything. */
+    if (source->state == SOURCE_SHUTDOWN)
+        return;
+
+    if (res)
     {
         send_buffer(stream, &buffer, token);
     }
@@ -555,12 +565,18 @@ static HRESULT WINAPI source_async_commands_Invoke(IMFAsyncCallback *iface, IMFA
     IUnknown *state;
     HRESULT hr;

-    if (source->state == SOURCE_SHUTDOWN)
-        return S_OK;
-
     if (FAILED(hr = IMFAsyncResult_GetState(result, &state)))
         return hr;

+    EnterCriticalSection(&source->cs);
+
+    if (source->state == SOURCE_SHUTDOWN)
+    {
+        LeaveCriticalSection(&source->cs);
+        IUnknown_Release(state);
+        return S_OK;
+    }
+
     command = impl_from_async_command_IUnknown(state);
     switch (command->op)
     {
@@ -581,6 +597,8 @@ static HRESULT WINAPI source_async_commands_Invoke(IMFAsyncCallback *iface, IMFA
             break;
     }

+    LeaveCriticalSection(&source->cs);
+
     IUnknown_Release(state);

return S_OK;