Merge pull request #43 from azr/release_failed_flock

Release failed flock

Author: theckman

flock.go

@@ -125,3 +125,11 @@ func (f *Flock) setFh() error {
 	f.fh = fh
 	return nil
 }
+
+// ensure the file handle is closed if no lock is held
+func (f *Flock) ensureFhState() {
+	if !f.l && !f.r && f.fh != nil {
+		f.fh.Close()
+		f.fh = nil
+	}
+}

flock_internal_test.go

@@ -0,0 +1,30 @@
+package flock
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func Test(t *testing.T) {
+	tmpFileFh, err := ioutil.TempFile(os.TempDir(), "go-flock-")
+	tmpFileFh.Close()
+	tmpFile := tmpFileFh.Name()
+	os.Remove(tmpFile)
+
+	lock := New(tmpFile)
+	locked, err := lock.TryLock()
+	if locked == false || err != nil {
+		t.Fatalf("failed to lock: locked: %t, err: %v", locked, err)
+	}
+
+	newLock := New(tmpFile)
+	locked, err = newLock.TryLock()
+	if locked != false || err != nil {
+		t.Fatalf("should have failed locking: locked: %t, err: %v", locked, err)
+	}
+
+	if newLock.fh != nil {
+		t.Fatal("file handle should have been released and be nil")
+	}
+}

flock_unix.go

@@ -51,6 +51,7 @@ func (f *Flock) lock(locked *bool, flag int) error {
 		if err := f.setFh(); err != nil {
 			return err
 		}
+		defer f.ensureFhState()
 	}
 
 	if err := syscall.Flock(int(f.fh.Fd()), flag); err != nil {
@@ -142,6 +143,7 @@ func (f *Flock) try(locked *bool, flag int) (bool, error) {
 		if err := f.setFh(); err != nil {
 			return false, err
 		}
+		defer f.ensureFhState()
 	}
 
 	var retried bool

flock_windows.go

@@ -46,6 +46,7 @@ func (f *Flock) lock(locked *bool, flag uint32) error {
 		if err := f.setFh(); err != nil {
 			return err
 		}
+		defer f.ensureFhState()
 	}
 
 	if _, errNo := lockFileEx(syscall.Handle(f.fh.Fd()), flag, 0, 1, 0, &syscall.Overlapped{}); errNo > 0 {
@@ -122,6 +123,7 @@ func (f *Flock) try(locked *bool, flag uint32) (bool, error) {
 		if err := f.setFh(); err != nil {
 			return false, err
 		}
+		defer f.ensureFhState()
 	}
 
 	_, errNo := lockFileEx(syscall.Handle(f.fh.Fd()), flag|winLockfileFailImmediately, 0, 1, 0, &syscall.Overlapped{})