com.alipay.common.tracer.util.CoolDown Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.alipay.common.tracer.util;
import java.util.concurrent.atomic.AtomicInteger;
/**
* A tool to reduce execution frequency of some unimportant operation(such as log duplicated error logs).
*
* created at 2021/4/7
*
* @author xiangfeng.xzc
*/
class CoolDown {
final long intervalMills;
final int times;
final AtomicInteger counter = new AtomicInteger(0);
final AtomicInteger wip = new AtomicInteger(0);
volatile long nextResetTime;
CoolDown(long resetIntervalMills, int times) {
this.intervalMills = resetIntervalMills;
this.times = times;
this.nextResetTime = System.currentTimeMillis() + resetIntervalMills;
}
boolean tryAcquire() {
while (true) {
int c = counter.get();
if (c < times) {
if (counter.compareAndSet(c, c + 1)) {
return true;
}
// CAS fail: retry loop
} else {
// Counter full in this period:
long now = System.currentTimeMillis();
if (now > nextResetTime) {
// wip acts like a SpinLock: only one thread can update 'nextResetTime' and 'counter'
if (wip.compareAndSet(0, 1)) {
if (now > nextResetTime) {
nextResetTime = now + intervalMills;
counter.set(0);
}
wip.set(0);
}
} else {
return false;
}
}
}
}
}