1 files changed, 51 insertions, 5 deletions
diff --git a/libgo/go/log/log.go b/libgo/go/log/log.go
index ac24b4deaa7..d34af9e5e45 100644
--- a/libgo/go/log/log.go
+++ b/libgo/go/log/log.go
@@ -19,6 +19,7 @@ import (
 	"runtime"
 	"os"
 	"time"
+	"sync"
 )
 
 // These flags define which text to prefix to each log entry generated by the Logger.
@@ -34,11 +35,15 @@ const (
 	Lshortfile                // final file name element and line number: d.go:23. overrides Llongfile
 )
 
-// Logger represents an active logging object.
+// A Logger represents an active logging object that generates lines of
+// output to an io.Writer.  Each logging operation makes a single call to
+// the Writer's Write method.  A Logger can be used simultaneously from
+// multiple goroutines; it guarantees to serialize access to the Writer.
 type Logger struct {
-	out    io.Writer // destination for output
-	prefix string    // prefix to write at beginning of each line
-	flag   int       // properties
+	mu     sync.Mutex // ensures atomic writes
+	out    io.Writer  // destination for output
+	prefix string     // prefix to write at beginning of each line
+	flag   int        // properties
 }
 
 // New creates a new Logger.   The out variable sets the
@@ -46,7 +51,7 @@ type Logger struct {
 // The prefix appears at the beginning of each generated log line.
 // The flag argument defines the logging properties.
 func New(out io.Writer, prefix string, flag int) *Logger {
-	return &Logger{out, prefix, flag}
+	return &Logger{out: out, prefix: prefix, flag: flag}
 }
 
 var std = New(os.Stderr, "", Ldate|Ltime)
@@ -139,6 +144,8 @@ func (l *Logger) Output(calldepth int, s string) os.Error {
 	if len(s) > 0 && s[len(s)-1] != '\n' {
 		buf.WriteByte('\n')
 	}
+	l.mu.Lock()
+	defer l.mu.Unlock()
 	_, err := l.out.Write(buf.Bytes())
 	return err
 }
@@ -157,6 +164,45 @@ func (l *Logger) Print(v ...interface{}) { l.Output(2, fmt.Sprint(v...)) }
 // Arguments are handled in the manner of fmt.Println.
 func (l *Logger) Println(v ...interface{}) { l.Output(2, fmt.Sprintln(v...)) }
 
+// Exit is equivalent to l.Print() followed by a call to os.Exit(1).
+func (l *Logger) Exit(v ...interface{}) {
+	l.Output(2, fmt.Sprint(v...))
+	os.Exit(1)
+}
+
+// Exitf is equivalent to l.Printf() followed by a call to os.Exit(1).
+func (l *Logger) Exitf(format string, v ...interface{}) {
+	l.Output(2, fmt.Sprintf(format, v...))
+	os.Exit(1)
+}
+
+// Exitln is equivalent to l.Println() followed by a call to os.Exit(1).
+func (l *Logger) Exitln(v ...interface{}) {
+	l.Output(2, fmt.Sprintln(v...))
+	os.Exit(1)
+}
+
+// Panic is equivalent to l.Print() followed by a call to panic().
+func (l *Logger) Panic(v ...interface{}) {
+	s := fmt.Sprint(v...)
+	l.Output(2, s)
+	panic(s)
+}
+
+// Panicf is equivalent to l.Printf() followed by a call to panic().
+func (l *Logger) Panicf(format string, v ...interface{}) {
+	s := fmt.Sprintf(format, v...)
+	l.Output(2, s)
+	panic(s)
+}
+
+// Panicln is equivalent to l.Println() followed by a call to panic().
+func (l *Logger) Panicln(v ...interface{}) {
+	s := fmt.Sprintln(v...)
+	l.Output(2, s)
+	panic(s)
+}
+
 // SetOutput sets the output destination for the standard logger.
 func SetOutput(w io.Writer) {
 	std.out = w