Druid——连接池动态调整之连接的淘汰

1.线程是DestroyTask，方法是shrink

2.现在还未弄清楚疑问点，后续继续研究

1)配置淘汰时间，不去判断哪些连接是否满足淘汰条件，直接把头部的几个放入淘汰数组

if (idleMillis >= minEvictableIdleTimeMillis) {
    if (checkTime && i < checkCount) {
        evictConnections[evictCount++] = connection;
        continue;
    } else if (idleMillis > maxEvictableIdleTimeMillis) {
        evictConnections[evictCount++] = connection;
        continue;
    }
}

2)为啥把需要淘汰的连接先都移除掉，没有根据淘汰的数量去移除，然后再判断数量是否满足条件，不满足又去创建连接

            int removeCount = evictCount + keepAliveCount;
            if (removeCount > 0) {
                System.arraycopy(connections, removeCount, connections, 0, poolingCount - removeCount);
                Arrays.fill(connections, poolingCount - removeCount, poolingCount, null);
                poolingCount -= removeCount;
            }
            keepAliveCheckCount += keepAliveCount;

            if (keepAlive && poolingCount + activeCount < minIdle) {
                needFill = true;
            }

if (needFill) {
    lock.lock();
    try {
        int fillCount = minIdle - (activeCount + poolingCount + createTaskCount);
        for (int i = 0; i < fillCount; ++i) {
            emptySignal();
        }
    } finally {
        lock.unlock();
    }
} else if (onFatalError || fatalErrorIncrement > 0) {
    lock.lock();
    try {
        emptySignal();
    } finally {
        lock.unlock();
    }
}