content: /*
   * Copyright 1999-2023 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.nacos.lock.core.reentrant.mutex;
  
  import com.alibaba.nacos.lock.core.reentrant.AbstractAtomicLock;
  import com.alibaba.nacos.lock.model.LockInfo;
  
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * MutexAtomicLock.
   *
   * @author 985492783@qq.com
   * @description MutexAtomicLock
   * @date 2023/7/10 15:33
   */
  public class MutexAtomicLock extends AbstractAtomicLock {
      
      private static final Integer EMPTY = 0;
      
      private static final Integer FULL = 1;
      
      private final AtomicInteger state;
      
      private Long expiredTimestamp;
      
      public MutexAtomicLock(String key) {
          super(key);
          this.state = new AtomicInteger(EMPTY);
      }
      
      @Override
      public Boolean tryLock(LockInfo lockInfo) {
          Long endTime = lockInfo.getEndTime();
          if (state.compareAndSet(EMPTY, FULL) || autoExpire()) {
              this.expiredTimestamp = endTime;
              return true;
          }
          return false;
      }
      
      @Override
      public Boolean unLock(LockInfo lockInfo) {
          return state.compareAndSet(FULL, EMPTY);
      }
      
      @Override
      public Boolean autoExpire() {
          return System.currentTimeMillis() >= this.expiredTimestamp;
      }
      
      @Override
      public Boolean isClear() {
          return EMPTY.equals(state.get()) || autoExpire();
      }
      
  }
  