pulseaudio: Rework stopping code that it should prevent artifacts

Rework stopping and stream closing code as it should prevent artifacts
when closing or stopping stream. Correctly handle stream termination
from callback

src/hostapi/pulseaudio/pa_linux_pulseaudio_cb.c

@@ -219,6 +219,37 @@ void _PaPulseAudio_Read( PaPulseAudio_Stream *stream,
 
 }
 
+static int _PaPulseaudio_WriteZero(PaPulseAudio_Stream *stream,
+                                    int32_t length)
+{
+    size_t tmpSize = length;
+    int ret = paContinue;
+    void *bufferData = NULL;
+
+    if( length <= 0)
+    {
+        return ret;
+    }
+
+    /* Allocate memory to make it faster to output stuff */
+    if( pa_stream_begin_write( stream->outputStream, &bufferData, &tmpSize ) )
+    {
+        PA_DEBUG( ("Portaudio %s: Can't output to stream!\n",
+        __FUNCTION__) );
+        return paInsufficientMemory;
+    }
+
+    memset( bufferData, 0x00, tmpSize);
+
+    pa_stream_write( stream->outputStream,
+                     bufferData,
+                     tmpSize,
+                     NULL,
+                     0,
+                     PA_SEEK_RELATIVE );
+    return ret;
+}
+
 static int _PaPulseAudio_ProcessAudio(PaPulseAudio_Stream *stream,
                                       size_t length)
 {
@@ -233,6 +264,7 @@ static int _PaPulseAudio_ProcessAudio(PaPulseAudio_Stream *stream,
     int ret = paContinue;
     void *bufferData = NULL;
     size_t pulseaudioOutputWritten = 0;
+    size_t pulseaudioLength = length;
 
     /* If there is no specified per host buffer then
      * just generate one or but correct one in place
@@ -293,19 +325,10 @@ static int _PaPulseAudio_ProcessAudio(PaPulseAudio_Stream *stream,
         pulseaudioInputBytes /= 2;
     }
 
-    if( !stream->isActive && stream->pulseaudioIsActive && stream->outputStream)
+    if( !stream->isActive && stream->outputStream)
     {
-        bufferData = pulseaudioSampleBuffer;
-        memset( bufferData, 0x00, length);
-
-        pa_stream_write( stream->outputStream,
-                         bufferData,
-                         length,
-                         NULL,
-                         0,
-                         PA_SEEK_RELATIVE );
-
-        return paContinue;
+        return _PaPulseaudio_WriteZero( stream,
+                                        pulseaudioLength );
     }
 
 
@@ -388,13 +411,10 @@ static int _PaPulseAudio_ProcessAudio(PaPulseAudio_Stream *stream,
             size_t tmpSize = pulseaudioOutputBytes;
 
             /* Allocate memory to make it faster to output stuff */
-            pa_stream_begin_write( stream->outputStream, &bufferData, &tmpSize );
-
-            /* If bufferData is NULL then output is not ready
-             * and we have to wait for it
-             */
-            if(!bufferData)
+            if( pa_stream_begin_write( stream->outputStream, &bufferData, &tmpSize ) )
             {
+                PA_DEBUG( ("Portaudio %s: Can't output to stream!\n",
+                __FUNCTION__) )
                 return paNotInitialized;
             }
 
@@ -426,6 +446,13 @@ static int _PaPulseAudio_ProcessAudio(PaPulseAudio_Stream *stream,
 
         PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer,
                                       hostFrameCount );
+
+        if( ret )
+        {
+            stream->isActive = 0;
+            return _PaPulseaudio_WriteZero( stream,
+                                            (length - pulseaudioOutputWritten) );
+        }
     }
 
     return ret;
@@ -518,8 +545,6 @@ PaError PaPulseAudio_CloseStreamCb( PaStream * s )
     /* Wait for stream to be stopped */
     stream->isActive = 0;
     stream->isStopped = 1;
-    stream->pulseaudioIsActive = 0;
-    stream->pulseaudioIsStopped = 1;
 
     if( stream->outputStream != NULL
         && PA_STREAM_IS_GOOD( pa_stream_get_state( stream->outputStream ) ) )
@@ -536,7 +561,6 @@ PaError PaPulseAudio_CloseStreamCb( PaStream * s )
                                        &pulseaudioOperation );
 
         PaPulseAudio_Lock(stream->mainloop);
-
         pa_stream_disconnect( stream->outputStream );
         PaPulseAudio_UnLock( stream->mainloop );
     }
@@ -598,6 +622,9 @@ PaError PaPulseAudio_CloseStreamCb( PaStream * s )
         usleep(10000);
     }
 
+    stream->pulseaudioIsActive = 0;
+    stream->pulseaudioIsStopped = 1;
+
     PaUtil_TerminateBufferProcessor( &stream->bufferProcessor );
     PaUtil_TerminateStreamRepresentation( &stream->streamRepresentation );
 
@@ -917,8 +944,6 @@ static PaError RequestStop( PaPulseAudio_Stream * stream,
     /* Wait for stream to be stopped */
     stream->isActive = 0;
     stream->isStopped = 1;
-    stream->pulseaudioIsActive = 0;
-    stream->pulseaudioIsStopped = 1;
 
     stream->missedBytes = 0;
 
@@ -941,8 +966,6 @@ static PaError RequestStop( PaPulseAudio_Stream * stream,
 
     requeststop_error:
     PaPulseAudio_UnLock( pulseaudioHostApi->mainloop );
-    stream->isActive = 0;
-    stream->isStopped = 1;
     stream->pulseaudioIsActive = 0;
     stream->pulseaudioIsStopped = 1;