Add PA ALSA extension to allow setting number of retries when busy

fredrikbergholtz-sr · May 24, 2009 · 822c292 · 822c292
1 parent 6e6e3ac
commit 822c292
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/include/pa_linux_alsa.h b/include/pa_linux_alsa.h
@@ -87,6 +87,11 @@ PaError PaAlsa_GetStreamOutputCard( PaStream *s, int *card );
  */
 PaError PaAlsa_SetNumPeriods( int numPeriods );
 
+/** Set the maximum number of times to retry opening busy device (sleeping for a
+ * short interval inbetween).
+ */
+PaError PaAlsa_SetRetriesBusy( int retries );
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/src/hostapi/alsa/pa_linux_alsa.c b/src/hostapi/alsa/pa_linux_alsa.c
@@ -100,6 +100,7 @@
 
 static int aErr_;               /* Used with ENSURE_ */
 static int numPeriods_ = 4;
+static int busyRetries_ = 100;
 
 int PaAlsa_SetNumPeriods( int numPeriods )
 {
@@ -539,7 +540,7 @@ static int IgnorePlugin( const char *pluginId )
  **/
 static int OpenPcm( snd_pcm_t **pcmp, const char *name, snd_pcm_stream_t stream, int mode, int waitOnBusy )
 {
-    int tries = 0, maxTries = waitOnBusy ? 100 : 0;
+    int tries = 0, maxTries = waitOnBusy ? busyRetries_ : 0;
     int ret = snd_pcm_open( pcmp, name, stream, mode );
     for( tries = 0; tries < maxTries && -EBUSY == ret; ++tries )
     {
@@ -3670,3 +3671,9 @@ PaError PaAlsa_GetStreamOutputCard(PaStream* s, int* card) {
 error:
     return result;
 }
+
+PaError PaAlsa_SetRetriesBusy( int retries )
+{
+    busyRetries_ = retries;
+    return paNoError;
+}