2 files changed, 64 insertions, 28 deletions

diff --git a/ethlog/loggers.go b/ethlog/loggers.go
index 50de213b3..b2760534b 100644
--- a/ethlog/loggers.go
+++ b/ethlog/loggers.go
@@ -39,7 +39,9 @@ func (msg *logMessage) send(logger LogSystem) {
 
 var logMessages chan (*logMessage)
 var logSystems []LogSystem
-var quit chan bool
+var quit chan chan error
+var drained chan bool
+var mutex = sync.Mutex{}
 
 type LogLevel uint8
 
@@ -52,34 +54,55 @@ const (
 	DebugDetailLevel
 )
 
+func dispatch(msg *logMessage) {
+	for _, logSystem := range logSystems {
+		if logSystem.GetLogLevel() >= msg.LogLevel {
+			msg.send(logSystem)
+		}
+	}
+}
+
 // log messages are dispatched to log writers
 func start() {
-out:
 	for {
 		select {
+		case status := <-quit:
+			status <- nil
+			return
 		case msg := <-logMessages:
-			for _, logSystem := range logSystems {
-				if logSystem.GetLogLevel() >= msg.LogLevel {
-					msg.send(logSystem)
-				}
-			}
-		case <-quit:
-			break out
+			dispatch(msg)
+		default:
+			drained <- true // this blocks until a message is sent to the queue
 		}
 	}
 }
 
-// waits until log messages are drained (dispatched to log writers)
-func Flush() {
-	quit <- true
+func send(msg *logMessage) {
+	logMessages <- msg
+	select {
+	case <-drained:
+	default:
+	}
+}
 
-done:
-	for {
+func Reset() {
+	mutex.Lock()
+	defer mutex.Unlock()
+	if logSystems != nil {
+		status := make(chan error)
+		quit <- status
 		select {
-		case <-logMessages:
+		case <-drained:
 		default:
-			break done
 		}
+		<-status
+	}
+}
+
+// waits until log messages are drained (dispatched to log writers)
+func Flush() {
+	if logSystems != nil {
+		<-drained
 	}
 }
 
@@ -97,7 +120,8 @@ func AddLogSystem(logSystem LogSystem) {
 	defer mutex.Unlock()
 	if logSystems == nil {
 		logMessages = make(chan *logMessage, 10)
-		quit = make(chan bool, 1)
+		quit = make(chan chan error, 1)
+		drained = make(chan bool, 1)
 		go start()
 	}
 	logSystems = append(logSystems, logSystem)
@@ -106,14 +130,14 @@ func AddLogSystem(logSystem LogSystem) {
 func (logger *Logger) sendln(level LogLevel, v ...interface{}) {
 	if logMessages != nil {
 		msg := newPrintlnLogMessage(level, logger.tag, v...)
-		logMessages <- msg
+		send(msg)
 	}
 }
 
 func (logger *Logger) sendf(level LogLevel, format string, v ...interface{}) {
 	if logMessages != nil {
 		msg := newPrintfLogMessage(level, logger.tag, format, v...)
-		logMessages <- msg
+		send(msg)
 	}
 }
 
diff --git a/ethlog/loggers_test.go b/ethlog/loggers_test.go
index 89f416681..a9b1463e7 100644
--- a/ethlog/loggers_test.go
+++ b/ethlog/loggers_test.go
@@ -28,8 +28,19 @@ func (t *TestLogSystem) GetLogLevel() LogLevel {
 	return t.level
 }
 
-func quote(s string) string {
-	return fmt.Sprintf("'%s'", s)
+func TestLoggerFlush(t *testing.T) {
+	logger := NewLogger("TEST")
+	testLogSystem := &TestLogSystem{level: WarnLevel}
+	AddLogSystem(testLogSystem)
+	for i := 0; i < 5; i++ {
+		logger.Errorf(".")
+	}
+	Flush()
+	Reset()
+	output := testLogSystem.Output
+	if output != "[TEST] .[TEST] .[TEST] .[TEST] .[TEST] ." {
+		t.Error("Expected complete logger output '[TEST] .[TEST] .[TEST] .[TEST] .[TEST] .', got ", output)
+	}
 }
 
 func TestLoggerPrintln(t *testing.T) {
@@ -41,10 +52,11 @@ func TestLoggerPrintln(t *testing.T) {
 	logger.Infoln("info")
 	logger.Debugln("debug")
 	Flush()
+	Reset()
 	output := testLogSystem.Output
 	fmt.Println(quote(output))
 	if output != "[TEST] error\n[TEST] warn\n" {
-		t.Error("Expected logger output '[TEST] error\\n[TEST] warn\\n', got ", quote(testLogSystem.Output))
+		t.Error("Expected logger output '[TEST] error\\n[TEST] warn\\n', got ", output)
 	}
 }
 
@@ -57,10 +69,10 @@ func TestLoggerPrintf(t *testing.T) {
 	logger.Infof("info")
 	logger.Debugf("debug")
 	Flush()
+	Reset()
 	output := testLogSystem.Output
-	fmt.Println(quote(output))
 	if output != "[TEST] error to { 2}\n[TEST] warn" {
-		t.Error("Expected logger output '[TEST] error to { 2}\\n[TEST] warn', got ", quote(testLogSystem.Output))
+		t.Error("Expected logger output '[TEST] error to { 2}\\n[TEST] warn', got ", output)
 	}
 }
 
@@ -73,13 +85,14 @@ func TestMultipleLogSystems(t *testing.T) {
 	logger.Errorln("error")
 	logger.Warnln("warn")
 	Flush()
+	Reset()
 	output0 := testLogSystem0.Output
 	output1 := testLogSystem1.Output
 	if output0 != "[TEST] error\n" {
-		t.Error("Expected logger 0 output '[TEST] error\\n', got ", quote(testLogSystem0.Output))
+		t.Error("Expected logger 0 output '[TEST] error\\n', got ", output0)
 	}
 	if output1 != "[TEST] error\n[TEST] warn\n" {
-		t.Error("Expected logger 1 output '[TEST] error\\n[TEST] warn\\n', got ", quote(testLogSystem1.Output))
+		t.Error("Expected logger 1 output '[TEST] error\\n[TEST] warn\\n', got ", output1)
 	}
 }
 
@@ -94,9 +107,8 @@ func TestFileLogSystem(t *testing.T) {
 	Flush()
 	contents, _ := ioutil.ReadFile(filename)
 	output := string(contents)
-	fmt.Println(quote(output))
 	if output != "[TEST] error to test.log\n[TEST] warn\n" {
-		t.Error("Expected contents of file 'test.log': '[TEST] error to test.log\\n[TEST] warn\\n', got ", quote(output))
+		t.Error("Expected contents of file 'test.log': '[TEST] error to test.log\\n[TEST] warn\\n', got ", output)
 	} else {
 		os.Remove(filename)
 	}