[PATCH v3 1/1] mmdevapi: Avoid race between main and notify thread.

[Bernhard Übelacker]

From: Bernhard Übelacker

The gitlab runners where showing a few flaky crashes in e.g. tests:
  dmsynth:dmsynth dmusic:dmusic winmm:midi

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58233
---
 dlls/mmdevapi/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dlls/mmdevapi/main.c b/dlls/mmdevapi/main.c
index 551d53ccb7f..1af6508c145 100644
--- a/dlls/mmdevapi/main.c
+++ b/dlls/mmdevapi/main.c
@@ -307,6 +307,7 @@ static IClassFactoryImpl MMDEVAPI_CF[] = {
 };

static INIT_ONCE init_once = INIT_ONCE_STATIC_INIT;
+static HANDLE notify_thread_handle;

HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 {
@@ -384,11 +385,14 @@ LRESULT WINAPI DriverProc( DWORD_PTR id, HANDLE driver, UINT msg, LPARAM param1,

params.err = &err;
         MIDI_CALL( midi_init, &params );
-        if (err == DRV_SUCCESS) CloseHandle( CreateThread( NULL, 0, notify_thread, NULL, 0, NULL ));
+        if (err == DRV_SUCCESS) notify_thread_handle = CreateThread( NULL, 0, notify_thread, NULL, 0, NULL );
         return err;
     }
     case DRV_FREE:
         MIDI_CALL( midi_release, NULL );
+        WaitForSingleObject( notify_thread_handle, INFINITE );
+        CloseHandle( notify_thread_handle );
+        notify_thread_handle = NULL;
         return 1;
     case DRV_OPEN:
     case DRV_CLOSE: