releases read/write busy flag on an exception

README.md

@@ -1,7 +1,18 @@
 PortAudio.jl
-==========
+============
 
 [![Build Status](https://travis-ci.org/JuliaAudio/PortAudio.jl.svg?branch=master)](https://travis-ci.org/JuliaAudio/PortAudio.jl)
 [![codecov.io] (http://codecov.io/github/JuliaAudio/PortAudio.jl/coverage.svg?branch=master)] (http://codecov.io/github/JuliaAudio/PortAudio.jl?branch=master)
 
-PortAudio.jl is a wrapper for [libportaudio](http://www.portaudio.com/), which gives cross-platform access to audio devices. It is compatible with the types defined in [SampleTypes.jl](https://github.com/JuliaAudio/SampleTypes.jl), so it provides `PASampleSink` and `PASampleSource` types, which can be read from and written to.
+PortAudio.jl is a wrapper for [libportaudio](http://www.portaudio.com/), which gives cross-platform access to audio devices. It is compatible with the types defined in [SampleTypes.jl](https://github.com/JuliaAudio/SampleTypes.jl), so it provides `PortAudioSink` and `PortAudioSource` types, which can be read from and written to.
+
+## Examples
+
+### Set up an audio pass-through from microphone to speaker
+
+```julia
+src = PortAudioSource()
+sink = PortAudioSink()
+write(sink, source)
+end
+```

src/PortAudio.jl

@@ -93,9 +93,10 @@ function SampleTypes.unsafe_write(sink::PortAudioSink, buf::SampleBuf)
         shift!(sink.waiters)
     end
 
-    sink.busy = true
     total = nframes(buf)
     written = 0
+    try
+        sink.busy = true
 
         while written < total
             n = min(size(sink.pabuf, 2), total-written, Pa_GetStreamWriteAvailable(sink.stream))
@@ -107,11 +108,14 @@ function SampleTypes.unsafe_write(sink::PortAudioSink, buf::SampleBuf)
             written += n
             sleep(POLL_SECONDS)
         end
+    finally
+        # make sure we release the busy flag even if the user ctrl-C'ed out
         sink.busy = false
         if length(sink.waiters) > 0
             # let the next task in line go
             notify(sink.waiters[1])
         end
+    end
 
     written
 end
@@ -124,11 +128,12 @@ function SampleTypes.unsafe_read!(source::PortAudioSource, buf::SampleBuf)
         shift!(source.waiters)
     end
 
-    source.busy = true
-
     total = nframes(buf)
     read = 0
 
+    try
+        source.busy = true
+
         while read < total
             n = min(size(source.pabuf, 2), total-read, Pa_GetStreamReadAvailable(source.stream))
             Pa_ReadStream(source.stream, source.pabuf, n, false)
@@ -140,11 +145,13 @@ function SampleTypes.unsafe_read!(source::PortAudioSource, buf::SampleBuf)
             sleep(POLL_SECONDS)
         end
 
+    finally
         source.busy = false
         if length(source.waiters) > 0
             # let the next task in line go
             notify(source.waiters[1])
         end
+    end
 
     read
 end