1 files changed, 9 insertions, 43 deletions
diff --git a/compiler_wrapper/rusage_flag.go b/compiler_wrapper/rusage_flag.go
index 690308b2..2a3768c1 100644
--- a/compiler_wrapper/rusage_flag.go
+++ b/compiler_wrapper/rusage_flag.go
@@ -18,26 +18,6 @@ func getRusageLogFilename(env env) string {
 	return value
 }
 
-func lockFileExclusive(fd uintptr) error {
-	maxTries := 100
-	for i := 0; i < maxTries; i++ {
-		const seekSet = 0
-		err := syscall.FcntlFlock(fd, syscall.F_SETLKW, &syscall.Flock_t{
-			Type:   syscall.F_WRLCK,
-			Whence: seekSet,
-			Start:  0,
-			Len:    0,
-		})
-		if err == nil {
-			return nil
-		}
-		if err != syscall.EINTR {
-			return fmt.Errorf("locking file: %v", err)
-		}
-	}
-	return fmt.Errorf("locking file failed after %d tries", maxTries)
-}
-
 func logRusage(env env, logFileName string, compilerCmd *command) (exitCode int, err error) {
 	rusageBefore := syscall.Rusage{}
 	if err := syscall.Getrusage(syscall.RUSAGE_CHILDREN, &rusageBefore); err != nil {
@@ -69,35 +49,21 @@ func logRusage(env env, logFileName string, compilerCmd *command) (exitCode int,
 	if err := os.MkdirAll(filepath.Dir(logFileName), 0777); err != nil {
 		return 0, wrapErrorwithSourceLocf(err, "error creating rusage log directory %s", logFileName)
 	}
-
-	timeUnit := float64(time.Second)
-	data := fmt.Sprintf("%.5f : %.5f : %.5f : %d : %s : %s\n",
-		float64(elapsedRealTime)/timeUnit, float64(elapsedUserTime)/timeUnit, float64(elapsedSysTime)/timeUnit,
-		maxMemUsed, absCompilerPath,
-		strings.Join(append([]string{filepath.Base(absCompilerPath)}, compilerCmd.Args...), " "))
-
 	// Note: using file mode 0666 so that a root-created log is writable by others.
 	logFile, err := os.OpenFile(logFileName, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0666)
 	if err != nil {
-		return 0, wrapErrorwithSourceLocf(err, "creating rusage logfile %s", logFileName)
+		return 0, wrapErrorwithSourceLocf(err, "error creating rusage logfile %s", logFileName)
 	}
-
-	// O_APPEND's atomicity guarantees are only for writes up to a certain size. If we don't
-	// lock the file, we might end up with corrupted records.
-	//
-	// Note that Close()'ing the file releases all associated locks.
-	if err := lockFileExclusive(logFile.Fd()); err != nil {
+	timeUnit := float64(time.Second)
+	if _, err := fmt.Fprintf(logFile, "%.5f : %.5f : %.5f : %d : %s : %s\n",
+		float64(elapsedRealTime)/timeUnit, float64(elapsedUserTime)/timeUnit, float64(elapsedSysTime)/timeUnit,
+		maxMemUsed, absCompilerPath,
+		strings.Join(append([]string{filepath.Base(absCompilerPath)}, compilerCmd.Args...), " ")); err != nil {
 		_ = logFile.Close()
-		return 0, wrapErrorwithSourceLocf(err, "locking rusage logfile %s: %v", logFileName, err)
-	}
-
-	_, err = logFile.WriteString(data)
-	closeErr := logFile.Close()
-	if err != nil {
-		return 0, wrapErrorwithSourceLocf(err, "writing to rusage logfile %s: %v", logFileName, err)
+		return 0, wrapErrorwithSourceLocf(err, "error writing rusage logfile %s", logFileName)
 	}
-	if closeErr != nil {
-		return 0, wrapErrorwithSourceLocf(err, "closing rusage logfile %s: %v", logFileName, closeErr)
+	if err := logFile.Close(); err != nil {
+		return 0, wrapErrorwithSourceLocf(err, "error closing rusage logfile %s", logFileName)
 	}
 
 	return exitCode, nil