fix occasional access violation crash when switching audio devices

omriharel · May 12, 2020 · e05c903 · e05c903
1 parent 6d19837
commit e05c903
Showing 1 changed file with 18 additions and 14 deletions.
diff --git a/session_finder_windows.go b/session_finder_windows.go
@@ -66,10 +66,12 @@ func (sf *wcaSessionFinder) GetAllSessions() ([]Session, error) {
  }
  defer defaultAudioEndpoint.Release()
 
- // receive notifications whenever the default device changes
- if err := sf.registerDefaultDeviceChangeCallback(); err != nil {
- sf.logger.Warnw("Failed to register default device change callback", "error", err)
- return nil, fmt.Errorf("register default device change callback: %w", err)
+ // receive notifications whenever the default device changes (only do this once)
+ if sf.mmNotificationClient == nil {
+ if err := sf.registerDefaultDeviceChangeCallback(); err != nil {
+ sf.logger.Warnw("Failed to register default device change callback", "error", err)
+ return nil, fmt.Errorf("register default device change callback: %w", err)
+ }
  }
 
  // get the master session
@@ -112,16 +114,18 @@ func (sf *wcaSessionFinder) Release() error {
 
 func (sf *wcaSessionFinder) getDefaultAudioEndpoint() (*wca.IMMDevice, error) {
 
- // get the IMMDeviceEnumerator
- if err := wca.CoCreateInstance(
- wca.CLSID_MMDeviceEnumerator,
- 0,
- wca.CLSCTX_ALL,
- wca.IID_IMMDeviceEnumerator,
- &sf.mmDeviceEnumerator,
- ); err != nil {
- sf.logger.Warnw("Failed to call CoCreateInstance", "error", err)
- return nil, fmt.Errorf("call CoCreateInstance: %w", err)
+ // get the IMMDeviceEnumerator (only once)
+ if sf.mmDeviceEnumerator == nil {
+ if err := wca.CoCreateInstance(
+ wca.CLSID_MMDeviceEnumerator,
+ 0,
+ wca.CLSCTX_ALL,
+ wca.IID_IMMDeviceEnumerator,
+ &sf.mmDeviceEnumerator,
+ ); err != nil {
+ sf.logger.Warnw("Failed to call CoCreateInstance", "error", err)
+ return nil, fmt.Errorf("call CoCreateInstance: %w", err)
+ }
  }
 
  // get the default audio endpoint as an IMMDevice