Locking loggers in case of multi-threaded apps. (Azure#171)

Author: jaer-tsun

log/logger.go

@@ -9,6 +9,7 @@ import (
 "log"
 "os"
 "path"
+"sync"
 )
 
 // Log level
@@ -50,6 +51,7 @@ type Logger struct {
 maxFileCount int
 callCount int
 directory string
+mutex *sync.Mutex
 }
 
 // NewLogger creates a new Logger.
@@ -63,6 +65,7 @@ func NewLogger(name string, level int, target int) *Logger {
 logger.maxFileSize = maxLogFileSize
 logger.maxFileCount = maxLogFileCount
 logger.directory = ""
+logger.mutex = &sync.Mutex{}
 
 return &logger
 }
@@ -185,13 +188,17 @@ func (logger *Logger) logf(format string, args ...interface{}) {
 // Printf logs a formatted string at info level.
 func (logger *Logger) Printf(format string, args ...interface{}) {
 if logger.level >= LevelInfo {
+logger.mutex.Lock()
 logger.logf(format, args...)
+logger.mutex.Unlock()
 }
 }
 
 // Debugf logs a formatted string at debug level.
 func (logger *Logger) Debugf(format string, args ...interface{}) {
 if logger.level >= LevelDebug {
+logger.mutex.Lock()
 logger.logf(format, args...)
+logger.mutex.Unlock()
 }
 }

log/stdapi.go

@@ -4,9 +4,9 @@
 package log
 
 // Standard logger is a pre-defined logger for convenience.
-var stdLog *Logger = NewLogger("azure-container-networking", LevelInfo, TargetStderr)
+var stdLog = NewLogger("azure-container-networking", LevelInfo, TargetStderr)
 
-// Helper functions for the standard logger.
+// GetStd - Helper functions for the standard logger.
 func GetStd() *Logger {
 return stdLog
 }