X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/b9d2799dfebae724dda3b3e28641116ca5daf5c7..318c49002aea966128a9d37ab29e601a104d79bb:/sdk/go/streamer/streamer.go

diff --git a/sdk/go/streamer/streamer.go b/sdk/go/streamer/streamer.go
index 0c4d208348..a46ca4cc55 100644
--- a/sdk/go/streamer/streamer.go
+++ b/sdk/go/streamer/streamer.go
@@ -36,8 +36,8 @@ Alternately, if you already have a filled buffer and just want to read out from
 package streamer
 
 import (
-	"io"
 	"errors"
+	"io"
 )
 
 var ErrAlreadyClosed = errors.New("cannot close a stream twice")
@@ -48,6 +48,7 @@ type AsyncStream struct {
 	add_reader        chan bool
 	subtract_reader   chan bool
 	wait_zero_readers chan bool
+	closed            bool
 }
 
 // Reads from the buffer managed by the Transfer()
@@ -58,7 +59,13 @@ type StreamReader struct {
 }
 
 func AsyncStreamFromReader(buffersize int, source io.Reader) *AsyncStream {
-	t := &AsyncStream{make([]byte, buffersize), make(chan sliceRequest), make(chan bool), make(chan bool), make(chan bool)}
+	t := &AsyncStream{
+		buffer:            make([]byte, buffersize),
+		requests:          make(chan sliceRequest),
+		add_reader:        make(chan bool),
+		subtract_reader:   make(chan bool),
+		wait_zero_readers: make(chan bool),
+	}
 
 	go t.transfer(source)
 	go t.readersMonitor()
@@ -67,7 +74,13 @@ func AsyncStreamFromReader(buffersize int, source io.Reader) *AsyncStream {
 }
 
 func AsyncStreamFromSlice(buf []byte) *AsyncStream {
-	t := &AsyncStream{buf, make(chan sliceRequest), make(chan bool), make(chan bool), make(chan bool)}
+	t := &AsyncStream{
+		buffer:            buf,
+		requests:          make(chan sliceRequest),
+		add_reader:        make(chan bool),
+		subtract_reader:   make(chan bool),
+		wait_zero_readers: make(chan bool),
+	}
 
 	go t.transfer(nil)
 	go t.readersMonitor()
@@ -127,10 +140,15 @@ func (this *StreamReader) Close() error {
 	return nil
 }
 
-func (this *AsyncStream) Close() {
+func (this *AsyncStream) Close() error {
+	if this.closed {
+		return ErrAlreadyClosed
+	}
+	this.closed = true
 	this.wait_zero_readers <- true
 	close(this.requests)
 	close(this.add_reader)
 	close(this.subtract_reader)
 	close(this.wait_zero_readers)
+	return nil
 }