/**
* Copyright 2016 Nikita Koksharov
*
* 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 org.redisson.api;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
/**
* Distributed implementation of {@link java.util.concurrent.locks.Lock}
* Implements reentrant lock.
* Use {@link RLock#getHoldCount()} to get a holds count.
*
* @author Nikita Koksharov
*
*/
public interface RLock extends Lock, RExpirable, RLockAsync {
/**
* Acquires the lock.
*
* <p>If the lock is not available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until the
* lock has been acquired.
*
* If the lock is acquired, it is held until <code>unlock</code> is invoked,
* or until leaseTime have passed
* since the lock was granted - whichever comes first.
*
* @param leaseTime the maximum time to hold the lock after granting it,
* before automatically releasing it if it hasn't already been released by invoking <code>unlock</code>.
* If leaseTime is -1, hold the lock until explicitly unlocked.
* @param unit the time unit of the {@code leaseTime} argument
* @throws InterruptedException - if the thread is interrupted before or during this method.
*/
void lockInterruptibly(long leaseTime, TimeUnit unit) throws InterruptedException;
/**
* Returns <code>true</code> as soon as the lock is acquired.
* If the lock is currently held by another thread in this or any
* other process in the distributed system this method keeps trying
* to acquire the lock for up to <code>waitTime</code> before
* giving up and returning <code>false</code>. If the lock is acquired,
* it is held until <code>unlock</code> is invoked, or until <code>leaseTime</code>
* have passed since the lock was granted - whichever comes first.
*
* @param waitTime the maximum time to aquire the lock
* @param leaseTime lease time
* @param unit time unit
* @return <code>true</code> if lock has been successfully acquired
* @throws InterruptedException - if the thread is interrupted before or during this method.
*/
boolean tryLock(long waitTime, long leaseTime, TimeUnit unit) throws InterruptedException;
/**
* Acquires the lock.
*
* <p>If the lock is not available then the current thread becomes
* disabled for thread scheduling purposes and lies dormant until the
* lock has been acquired.
*
* If the lock is acquired, it is held until <code>unlock</code> is invoked,
* or until leaseTime milliseconds have passed
* since the lock was granted - whichever comes first.
*
* @param leaseTime the maximum time to hold the lock after granting it,
* before automatically releasing it if it hasn't already been released by invoking <code>unlock</code>.
* If leaseTime is -1, hold the lock until explicitly unlocked.
* @param unit the time unit of the {@code leaseTime} argument
*
*/
void lock(long leaseTime, TimeUnit unit);
/**
* Unlocks lock independently of state
*
*/
void forceUnlock();
/**
* Checks if this lock locked by any thread
*
* @return <code>true</code> if locked otherwise <code>false</code>
*/
boolean isLocked();
/**
* Checks if this lock is held by the current thread
*
* @return <code>true</code> if held by current thread
* otherwise <code>false</code>
*/
boolean isHeldByCurrentThread();
/**
* Number of holds on this lock by the current thread
*
* @return holds or <code>0</code> if this lock is not held by current thread
*/
int getHoldCount();
}