content: /*
   * Copyright 1999-2018 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.csp.sentinel.demo.flow;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import com.alibaba.csp.sentinel.util.TimeUtil;
  import com.alibaba.csp.sentinel.Entry;
  import com.alibaba.csp.sentinel.SphU;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  import com.alibaba.csp.sentinel.slots.block.RuleConstant;
  import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
  import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
  
  /**
   * @author jialiang.linjl
   */
  public class FlowThreadDemo {
  
      private static AtomicInteger pass = new AtomicInteger();
      private static AtomicInteger block = new AtomicInteger();
      private static AtomicInteger total = new AtomicInteger();
      private static AtomicInteger activeThread = new AtomicInteger();
  
      private static volatile boolean stop = false;
      private static final int threadCount = 100;
  
      private static int seconds = 60 + 40;
      private static volatile int methodBRunningTime = 2000;
  
      public static void main(String[] args) throws Exception {
          System.out.println(
              "MethodA will call methodB. After running for a while, methodB becomes fast, "
                  + "which make methodA also become fast ");
          tick();
          initFlowRule();
  
          for (int i = 0; i < threadCount; i++) {
              Thread entryThread = new Thread(new Runnable() {
                  @Override
                  public void run() {
                      while (true) {
                          Entry methodA = null;
                          try {
                              TimeUnit.MILLISECONDS.sleep(5);
                              methodA = SphU.entry("methodA");
                              activeThread.incrementAndGet();
                              Entry methodB = SphU.entry("methodB");
                              TimeUnit.MILLISECONDS.sleep(methodBRunningTime);
                              methodB.exit();
                              pass.addAndGet(1);
                          } catch (BlockException e1) {
                              block.incrementAndGet();
                          } catch (Exception e2) {
                              // biz exception
                          } finally {
                              total.incrementAndGet();
                              if (methodA != null) {
                                  methodA.exit();
                                  activeThread.decrementAndGet();
                              }
                          }
                      }
                  }
              });
              entryThread.setName("working thread");
              entryThread.start();
          }
      }
  
      private static void initFlowRule() {
          List<FlowRule> rules = new ArrayList<FlowRule>();
          FlowRule rule1 = new FlowRule();
          rule1.setResource("methodA");
          // set limit concurrent thread for 'methodA' to 20
          rule1.setCount(20);
          rule1.setGrade(RuleConstant.FLOW_GRADE_THREAD);
          rule1.setLimitApp("default");
  
          rules.add(rule1);
          FlowRuleManager.loadRules(rules);
      }
  
      private static void tick() {
          Thread timer = new Thread(new TimerTask());
          timer.setName("sentinel-timer-task");
          timer.start();
      }
  
      static class TimerTask implements Runnable {
  
          @Override
          public void run() {
              long start = System.currentTimeMillis();
              System.out.println("begin to statistic!!!");
  
              long oldTotal = 0;
              long oldPass = 0;
              long oldBlock = 0;
  
              while (!stop) {
                  try {
                      TimeUnit.SECONDS.sleep(1);
                  } catch (InterruptedException e) {
                  }
                  long globalTotal = total.get();
                  long oneSecondTotal = globalTotal - oldTotal;
                  oldTotal = globalTotal;
  
                  long globalPass = pass.get();
                  long oneSecondPass = globalPass - oldPass;
                  oldPass = globalPass;
  
                  long globalBlock = block.get();
                  long oneSecondBlock = globalBlock - oldBlock;
                  oldBlock = globalBlock;
  
                  System.out.println(seconds + " total qps is: " + oneSecondTotal);
                  System.out.println(TimeUtil.currentTimeMillis() + ", total:" + oneSecondTotal
                      + ", pass:" + oneSecondPass
                      + ", block:" + oneSecondBlock
                      + " activeThread:" + activeThread.get());
                  if (seconds-- <= 0) {
                      stop = true;
                  }
                  if (seconds == 40) {
                      System.out.println("method B is running much faster; more requests are allowed to pass");
                      methodBRunningTime = 20;
                  }
              }
  
              long cost = System.currentTimeMillis() - start;
              System.out.println("time cost: " + cost + " ms");
              System.out.println("total:" + total.get() + ", pass:" + pass.get()
                  + ", block:" + block.get());
              System.exit(0);
          }
      }
  }
  