package flock import ( "os" "path/filepath" "testing" "github.com/prometheus/prometheus/utility/test" ) func TestLocking(t *testing.T) { dir := test.NewTemporaryDirectory("test_flock", t) defer dir.Close() fileName := filepath.Join(dir.Path(), "LOCK") if _, err := os.Stat(fileName); err == nil { t.Fatalf("File %q unexpectedly exists.", fileName) } lock, existed, err := New(fileName) if err != nil { t.Fatalf("Error locking file %q: %s", fileName, err) } if existed { t.Errorf("File %q reported as existing during locking.", fileName) } // File must now exist. if _, err := os.Stat(fileName); err != nil { t.Errorf("Could not stat file %q expected to exist: %s", fileName, err) } // Try to lock again. lockedAgain, existed, err := New(fileName) if err == nil { t.Fatalf("File %q locked twice.", fileName) } if lockedAgain != nil { t.Error("Unsuccessful locking did not return nil.") } if !existed { t.Errorf("Existing file %q not recognized.", fileName) } if err := lock.Release(); err != nil { t.Errorf("Error releasing lock for file %q: %s", fileName, err) } // File must still exist. if _, err := os.Stat(fileName); err != nil { t.Errorf("Could not stat file %q expected to exist: %s", fileName, err) } // Lock existing file. lock, existed, err = New(fileName) if err != nil { t.Fatalf("Error locking file %q: %s", fileName, err) } if !existed { t.Errorf("Existing file %q not recognized.", fileName) } if err := lock.Release(); err != nil { t.Errorf("Error releasing lock for file %q: %s", fileName, err) } }