Add lockutil test

Verify that the lock works for threads in the same process.

TODO:
- Test the lock also for multiple processes

Signed-off-by: Nir Soffer <[email protected]>

pkg/lockutil/lockutil_test.go

@@ -0,0 +1,56 @@
+package lockutil
+
+import (
+ "errors"
+ "fmt"
+ "os"
+ "path/filepath"
+ "strings"
+ "testing"
+)
+
+const parallel = 20
+
+func TestWithDirLock(t *testing.T) {
+ dir := t.TempDir()
+ log := filepath.Join(dir, "log")
+
+ errc := make(chan error, 10)
+ for i := 0; i < parallel; i++ {
+ go func() {
+ err := WithDirLock(dir, func() error {
+ if _, err := os.Stat(log); err == nil {
+ return nil
+ } else if !errors.Is(err, os.ErrNotExist) {
+ return err
+ }
+ logFile, err := os.OpenFile(log, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o640)
+ if err != nil {
+ return err
+ }
+ defer logFile.Close()
+ if _, err := fmt.Fprintf(logFile, "writer %d\n", i); err != nil {
+ return err
+ }
+ return logFile.Close()
+ })
+ errc <- err
+ }()
+ }
+
+ for i := 0; i < parallel; i++ {
+ err := <-errc
+ if err != nil {
+ t.Error(err)
+ }
+ }
+
+ data, err := os.ReadFile(log)
+ if err != nil {
+ t.Fatal(err)
+ }
+ lines := strings.Split(strings.Trim(string(data), "\n"), "\n")
+ if len(lines) != 1 {
+ t.Errorf("Expected one writer, got %v", lines)
+ }
+}