Fix bug 182 - Crash playing/freeze removing large number of tracks

Patch by Rick Yorgason
I modified it to use linear instead of n squared ring buffer size after verifying that this yields better performance on my mac and pc.

src/AudioIO.cpp

@@ -1138,6 +1138,10 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
    mPlayLooped = playLooped;
    mCutPreviewGapStart = cutPreviewGapStart;
    mCutPreviewGapLen = cutPreviewGapLen;
+   mPlaybackBuffers = NULL;
+   mPlaybackMixers = NULL;
+   mCaptureBuffers = NULL;
+   mResample = NULL;
 
    double factor = 1.0;
    if (mTimeTrack)
@@ -1152,11 +1156,11 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
    // killing performance.
    //
 
-   mPlaybackRingBufferSecs = 4.5 + (0.5 * mPlaybackTracks.GetCount());
+   mPlaybackRingBufferSecs = 10.0;
-   mMaxPlaybackSecsToCopy = 0.75 + (0.25 * mPlaybackTracks.GetCount());
+   mMaxPlaybackSecsToCopy = 4.0;
 
-   mCaptureRingBufferSecs = 4.5 + 0.5 * mCaptureTracks.GetCount();   
+   mCaptureRingBufferSecs = 4.5 + 0.5 * std::min(size_t(16), mCaptureTracks.GetCount());
-   mMinCaptureSecsToCopy = 0.2 + (0.2 * mCaptureTracks.GetCount());
+   mMinCaptureSecsToCopy = 0.2 + 0.2 * std::min(size_t(16), mCaptureTracks.GetCount());
 
    unsigned int playbackChannels = 0;
    unsigned int captureChannels = 0;
@@ -1219,16 +1223,35 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
    // allocate the memory structures the stream will need.
    //
 
+   bool bDone;
+   do
+   {
+      bDone = true; // assume success
+      try
+      {
          if( mNumPlaybackChannels > 0 ) {
             // Allocate output buffers.  For every output track we allocate
             // a ring buffer of five seconds
             sampleCount playbackBufferSize =
-         (sampleCount)(mRate * mPlaybackRingBufferSecs + 0.5);
+               (sampleCount)(mRate * mPlaybackRingBufferSecs + 0.5f);
             sampleCount playbackMixBufferSize = 
-         (sampleCount)(mRate * mMaxPlaybackSecsToCopy + 0.5);
+               (sampleCount)(mRate * mMaxPlaybackSecsToCopy + 0.5f);
+
+            // In the extraordinarily rare case that we can't even afford 100 samples, just give up.
+            if(playbackBufferSize < 100 || playbackMixBufferSize < 100)
+            {
+               StartStreamCleanup();
+               wxMessageBox(_("Out of memory!"));
+               return 0;
+            }
+
             mPlaybackBuffers = new RingBuffer* [mPlaybackTracks.GetCount()];
             mPlaybackMixers  = new Mixer*      [mPlaybackTracks.GetCount()];
 
+            // Set everything to zero in case we have to delete these due to a memory exception.
+            memset(mPlaybackBuffers, NULL, sizeof(RingBuffer*)*mPlaybackTracks.GetCount());
+            memset(mPlaybackMixers, NULL, sizeof(Mixer*)*mPlaybackTracks.GetCount());
+
             for( unsigned int i = 0; i < mPlaybackTracks.GetCount(); i++ )
             {
                mPlaybackBuffers[i] = new RingBuffer(floatSample, playbackBufferSize);
@@ -1247,10 +1270,23 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
             // a ring buffer of five seconds
             sampleCount captureBufferSize =
                (sampleCount)(mRate * mCaptureRingBufferSecs + 0.5);
+
+            // In the extraordinarily rare case that we can't even afford 100 samples, just give up.
+            if(captureBufferSize < 100)
+            {
+               StartStreamCleanup();
+               wxMessageBox(_("Out of memory!"));
+               return 0;
+            }
+
             mCaptureBuffers = new RingBuffer* [mCaptureTracks.GetCount()];
             mResample = new Resample* [mCaptureTracks.GetCount()];
             mFactor = sampleRate / mRate;
 
+            // Set everything to zero in case we have to delete these due to a memory exception.
+            memset(mCaptureBuffers, NULL, sizeof(RingBuffer*)*mCaptureTracks.GetCount());
+            memset(mResample, NULL, sizeof(Resample*)*mCaptureTracks.GetCount());
+
             for( unsigned int i = 0; i < mCaptureTracks.GetCount(); i++ )
             {
                mCaptureBuffers[i] = new RingBuffer( mCaptureTracks[i]->GetSampleFormat(),
@@ -1258,6 +1294,19 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
                mResample[i] = new Resample( true, mFactor, mFactor );
             }
          }
+      }
+      catch(std::bad_alloc&)
+      {
+         // Oops!  Ran out of memory.  This is pretty rare, so we'll just
+         // try deleting everything, halving our buffer size, and try again.
+         StartStreamCleanup(true);
+         mPlaybackRingBufferSecs *= 0.5;
+         mMaxPlaybackSecsToCopy *= 0.5;
+         mCaptureRingBufferSecs *= 0.5;
+         mMinCaptureSecsToCopy *= 0.5;
+         bDone = false;
+       }
+   } while(!bDone);
 
 #ifdef AUTOMATED_INPUT_LEVEL_ADJUSTMENT
    AILASetStartTime();
@@ -1288,13 +1337,10 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
 
       if( err != paNoError )
       {
-         // TODO
-         // we'll need a more complete way to indicate error.
-         // AND we need to delete the ring buffers and mixers, etc.
          if (mListener && mNumCaptureChannels > 0)
             mListener->OnAudioIOStopRecording();
-         wxPrintf(wxT("%hs\n"), Pa_GetErrorText(err));
+         StartStreamCleanup();
-         mStreamToken = 0;
+         wxMessageBox(LAT1CTOWX(Pa_GetErrorText(err)));
          return 0;
       }
    }
@@ -1318,6 +1364,49 @@ int AudioIO::StartStream(WaveTrackArray playbackTracks,
    return mStreamToken;
 }
 
+void AudioIO::StartStreamCleanup(bool bOnlyBuffers)
+{
+   if(mPlaybackBuffers)
+   {
+      for( unsigned int i = 0; i < mPlaybackTracks.GetCount(); i++ )
+         delete mPlaybackBuffers[i];
+      delete [] mPlaybackBuffers;
+      mPlaybackBuffers = NULL;
+   }
+
+   if(mPlaybackMixers)
+   {
+      for( unsigned int i = 0; i < mPlaybackTracks.GetCount(); i++ )
+         delete mPlaybackMixers[i];
+      delete [] mPlaybackMixers;
+      mPlaybackMixers = NULL;
+   }
+
+   if(mCaptureBuffers)
+   {
+
+         delete mCaptureBuffers;
+      delete [] mCaptureBuffers;
+      mCaptureBuffers = NULL;
+   }
+
+   if(mResample)
+   {
+      for( unsigned int i = 0; i < mCaptureTracks.GetCount(); i++ )
+         delete mResample;
+      delete [] mResample;
+      mResample = NULL;
+   }
+
+   if(!bOnlyBuffers)
+   {
+      Pa_AbortStream( mPortStreamV19 );
+      Pa_CloseStream( mPortStreamV19 );
+      mPortStreamV19 = NULL;
+      mStreamToken = 0;
+   }
+}
+
 #ifdef EXPERIMENTAL_MIDI_OUT
 
 PmTimestamp MidiTime(void *info)

src/AudioIO.h

@@ -399,6 +399,11 @@ private:
 
    double NormalizeStreamTime(double absoluteTime) const;
 
+   /** \brief Clean up after StartStream if it fails.
+     *
+     * If bOnlyBuffers is specified, it only cleans up the buffers. */
+   void StartStreamCleanup(bool bOnlyBuffers = false);
+
 #ifdef EXPERIMENTAL_MIDI_OUT
    //   MIDI_PLAYBACK:
    PmStream        *mMidiStream;