2 * Copyright © 2019 Damyan Ivanov.
3 * This file is part of MoLe.
4 * MoLe is free software: you can distribute it and/or modify it
5 * under the term of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your opinion), any later version.
9 * MoLe is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License terms for details.
14 * You should have received a copy of the GNU General Public License
15 * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
18 package net.ktnx.mobileledger.utils;
20 import java.util.concurrent.locks.Lock;
22 public class LockHolder implements AutoCloseable {
23 private Lock rLock, wLock;
24 LockHolder(Lock rLock) {
28 LockHolder(Lock rLock, Lock wLock) {
34 if (wLock != null) { wLock.unlock(); wLock = null; }
35 if (rLock != null) { rLock.unlock(); rLock = null; }
37 public void downgrade() {
38 if (rLock == null) throw new IllegalStateException("no locks are held");
40 if (wLock == null) return;