diff --git a/README.md b/README.md
index 428400c..0da5414 100644
--- a/README.md
+++ b/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
+```
diff --git a/src/PortAudio.jl b/src/PortAudio.jl
index b5a3be4..3c37825 100644
--- a/src/PortAudio.jl
+++ b/src/PortAudio.jl
@@ -93,24 +93,28 @@ 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))
-        bufstart = 1+written
-        bufend = n+written
-        @devec sink.jlbuf[1:n, :] = buf[bufstart:bufend, :]
-        transpose!(sink.pabuf, sink.jlbuf)
-        Pa_WriteStream(sink.stream, sink.pabuf, n, false)
-        written += n
-        sleep(POLL_SECONDS)
-    end
-    sink.busy = false
-    if length(sink.waiters) > 0
-        # let the next task in line go
-        notify(sink.waiters[1])
+        while written < total
+            n = min(size(sink.pabuf, 2), total-written, Pa_GetStreamWriteAvailable(sink.stream))
+            bufstart = 1+written
+            bufend = n+written
+            @devec sink.jlbuf[1:n, :] = buf[bufstart:bufend, :]
+            transpose!(sink.pabuf, sink.jlbuf)
+            Pa_WriteStream(sink.stream, sink.pabuf, n, false)
+            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
@@ -124,26 +128,29 @@ function SampleTypes.unsafe_read!(source::PortAudioSource, buf::SampleBuf)
         shift!(source.waiters)
     end
 
-    source.busy = true
-
     total = nframes(buf)
     read = 0
 
-    while read < total
-        n = min(size(source.pabuf, 2), total-read, Pa_GetStreamReadAvailable(source.stream))
-        Pa_ReadStream(source.stream, source.pabuf, n, false)
-        transpose!(source.jlbuf, source.pabuf)
-        bufstart = 1+read
-        bufend = n+read
-        @devec buf[bufstart:bufend, :] = source.jlbuf[1:n, :]
-        read += n
-        sleep(POLL_SECONDS)
-    end
+    try
+        source.busy = true
 
-    source.busy = false
-    if length(source.waiters) > 0
-        # let the next task in line go
-        notify(source.waiters[1])
+        while read < total
+            n = min(size(source.pabuf, 2), total-read, Pa_GetStreamReadAvailable(source.stream))
+            Pa_ReadStream(source.stream, source.pabuf, n, false)
+            transpose!(source.jlbuf, source.pabuf)
+            bufstart = 1+read
+            bufend = n+read
+            @devec buf[bufstart:bufend, :] = source.jlbuf[1:n, :]
+            read += n
+            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