net.lulihu.lock.ConditionLock Maven / Gradle / Ivy

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package net.lulihu.lock;

import lombok.extern.slf4j.Slf4j;
import net.lulihu.ObjectKit.LogKit;
import net.lulihu.dataStructure.LRULinkedHashMap;
import net.lulihu.exception.ToolBoxException;

import java.util.Map;
import java.util.concurrent.locks.Condition;

/**
 * 条件锁
 */
@Slf4j
public class ConditionLock {

    // 当前的持有条件的增量
    private final int incremental;
    private final OrderExecuteLockKit orderExecuteLock;
    private final Condition condition;

    ConditionLock(int incremental, Condition condition, OrderExecuteLockKit orderExecuteLock) {
        this.incremental = incremental;
        this.orderExecuteLock = orderExecuteLock;
        this.condition = condition;
    }

    /**
     * 获取锁
     */
    public void getLock() {
        // 先行判断 是否被释放
        Map.Entry currentCondition = getCurrentConditionMap();
        if (currentCondition == null) return;
        Integer incremental = currentCondition.getKey();
        if (this.incremental < incremental)
            throw new ToolBoxException("当前线程持有的条件已经被释放...");

        orderExecuteLock.getLock();

        boolean boo = true;
        do {
            currentCondition = getCurrentConditionMap();
            if (currentCondition == null) return;
            incremental = currentCondition.getKey();
            if (!incremental.equals(this.incremental)) {
                try {
                    condition.await();
                } catch (InterruptedException e) {
                    if (Thread.interrupted()) {
                        LogKit.warn(log, "线程等待过程中被打断...");
                    }
                }
            } else boo = false;
        } while (boo);
    }

    /**
     * 使用结束释放锁
     */
    public void unlock() {
        Map.Entry currentCondition = getCurrentConditionMap();
        if (currentCondition == null) return;
        Integer incremental = currentCondition.getKey();
        if (!incremental.equals(this.incremental)) {
            throw new ToolBoxException("当前线程持有的条件还未获取到锁或条件已经被释放...");
        }

        getIncrementalSignalMap().remove(incremental);

        try {
            Map.Entry currentConditionMap = getCurrentConditionMap();
            if (currentConditionMap != null)
                currentConditionMap.getValue().signalAll();
        } finally {
            orderExecuteLock.unlock();
        }
    }

    private Map.Entry getCurrentConditionMap() {
        LRULinkedHashMap incrementalSignalMap = getIncrementalSignalMap();
        if (incrementalSignalMap.isEmpty()) return null;
        return incrementalSignalMap.getHead();
    }

    private LRULinkedHashMap getIncrementalSignalMap() {
        return orderExecuteLock.getIncrementalSignalMap();
    }

}