[PATCH 0/1] MR973: mf: Avoid clearing media session command list while it is running.

[Rémi Bernon (＠rbernon)]

Split from https://gitlab.winehq.org/wine/wine/-/merge_requests/874, as it's fairly unrelated. This alone should fix mfmediaengine tests frequent crashes. They don't cause the test pipeline to fail, but they render the tests pretty much void.

[PATCH 1/1] mf: Avoid clearing media session command list while it is running.

[Rémi Bernon]

From: Rémi Bernon

This fixes a random crash with mfmediaengine tests, which quickly starts
then shuts down a media session.
---
 dlls/mf/session.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/mf/session.c b/dlls/mf/session.c
index 8be3ffcd7f3..b410a5fe861 100644
--- a/dlls/mf/session.c
+++ b/dlls/mf/session.c
@@ -47,6 +47,7 @@ enum session_command
     SESSION_CMD_PAUSE,
     SESSION_CMD_STOP,
     SESSION_CMD_SET_RATE,
+    SESSION_CMD_SHUTDOWN,
 };

struct session_op
@@ -460,7 +461,10 @@ static HRESULT session_submit_command(struct media_session *session, struct sess
     {
         if (list_empty(&session->commands) && !(session->presentation.flags & SESSION_FLAG_PENDING_COMMAND))
             hr = MFPutWorkItem(MFASYNC_CALLBACK_QUEUE_STANDARD, &session->commands_callback, &op->IUnknown_iface);
-        list_add_tail(&session->commands, &op->entry);
+        if (op->command == SESSION_CMD_SHUTDOWN)
+            list_add_head(&session->commands, &op->entry);
+        else
+            list_add_tail(&session->commands, &op->entry);
         IUnknown_AddRef(&op->IUnknown_iface);
     }
     LeaveCriticalSection(&session->cs);
@@ -2041,7 +2045,7 @@ static HRESULT WINAPI mfsession_Shutdown(IMFMediaSession *iface)
         IMFPresentationClock_Release(session->clock);
         session->clock = NULL;
         session_clear_presentation(session);
-        session_clear_command_list(session);
+        session_submit_simple_command(session, SESSION_CMD_SHUTDOWN);
     }
     LeaveCriticalSection(&session->cs);

@@ -2383,6 +2387,10 @@ static HRESULT WINAPI session_commands_callback_Invoke(IMFAsyncCallback *iface,
         case SESSION_CMD_SET_RATE:
             session_set_rate(session, op->set_rate.thin, op->set_rate.rate);
             break;
+        case SESSION_CMD_SHUTDOWN:
+            session_clear_command_list(session);
+            session_command_complete(session);
+            break;
         default:
             ;
     }

[Nikolay Sivov (＠nsivov)]

This looks fine (or safe?), but could you explain what is crashing exactly? Is it because the list is cleared right away, but some earlier async command could still reach Invoke() ?

[Rémi Bernon (＠rbernon)]

On Sun Oct  2 22:01:26 2022 +0000, Nikolay Sivov wrote:
> This looks fine (or safe?), but could you explain what is crashing
> exactly? Is it because the list is cleared right away, but some earlier
> async command could still reach Invoke() ?

Yes, and then the command is removed twice from the list.

[PATCH 0/1] MR973: mf: Avoid clearing media session command list while it is running. - approved

[Nikolay Sivov (＠nsivov)]

This merge request was approved by Nikolay Sivov.