added park/unpark bindings and simple test for it

Author: JkLondon

mdbx/txn.go

@@ -313,6 +313,34 @@ func (txn *Txn) abort() {
 	txn.clearTxn()
 }
 
+func (txn *Txn) Park(autounpark bool) error {
+	if txn._txn == nil {
+		return nil
+	}
+
+	if txn.env._env != nil {
+		ret := C.mdbx_txn_park(txn._txn, C.bool(autounpark))
+		if ret != success {
+			return operrno("mdbx_txn_park", ret)
+		}
+	}
+	return nil
+}
+
+func (txn *Txn) Unpark(restartIfOusted bool) error {
+	if txn._txn == nil {
+		return nil
+	}
+
+	if txn.env._env != nil {
+		ret := C.mdbx_txn_unpark(txn._txn, C.bool(restartIfOusted))
+		if ret != success {
+			return operrno("mdbx_txn_park", ret)
+		}
+	}
+	return nil
+}
+
 func (txn *Txn) clearTxn() {
 	// Clear the C object to prevent any potential future use of the freed
 	// pointer.

mdbx/txn_test.go

@@ -717,6 +717,27 @@ func TestTxn_Reset_doubleReset(t *testing.T) {
 	txn.Reset()
 }
 
+func TestTxn_ParkUnpark(t *testing.T) {
+	env, _ := setup(t)
+
+	txn, err := env.BeginTxn(nil, Readonly)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer txn.Abort()
+	err = txn.Park(true)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	err = txn.Unpark(true)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+}
+
 // This test demonstrates that Reset/Renew have no effect on writable
 // transactions. The transaction may be committed after Reset/Renew are called.
 func TestTxn_Reset_writeTxn(t *testing.T) {