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.system;
  
  import java.util.ArrayList;
  import java.util.Collections;
  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.EntryType;
  import com.alibaba.csp.sentinel.SphU;
  import com.alibaba.csp.sentinel.slots.block.BlockException;
  import com.alibaba.csp.sentinel.slots.system.SystemRule;
  import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
  
  /**
   * @author jialiang.linjl
   */
  public class SystemGuardDemo {
  
      private static AtomicInteger pass = new AtomicInteger();
      private static AtomicInteger block = new AtomicInteger();
      private static AtomicInteger total = new AtomicInteger();
  
      private static volatile boolean stop = false;
      private static final int threadCount = 100;
  
      private static int seconds = 60 + 40;
  
      public static void main(String[] args) throws Exception {
  
          tick();
          initSystemRule();
  
          for (int i = 0; i < threadCount; i++) {
              Thread entryThread = new Thread(new Runnable() {
                  @Override
                  public void run() {
                      while (true) {
                          Entry entry = null;
                          try {
                              entry = SphU.entry("methodA", EntryType.IN);
                              pass.incrementAndGet();
                              try {
                                  TimeUnit.MILLISECONDS.sleep(20);
                              } catch (InterruptedException e) {
                                  // ignore
                              }
                          } catch (BlockException e1) {
                              block.incrementAndGet();
                              try {
                                  TimeUnit.MILLISECONDS.sleep(20);
                              } catch (InterruptedException e) {
                                  // ignore
                              }
                          } catch (Exception e2) {
                              // biz exception
                          } finally {
                              total.incrementAndGet();
                              if (entry != null) {
                                  entry.exit();
                              }
                          }
                      }
                  }
  
              });
              entryThread.setName("working-thread");
              entryThread.start();
          }
      }
  
      private static void initSystemRule() {
          SystemRule rule = new SystemRule();
          // max load is 3
          rule.setHighestSystemLoad(3.0);
          // max cpu usage is 60%
          rule.setHighestCpuUsage(0.6);
          // max avg rt of all request is 10 ms
          rule.setAvgRt(10);
          // max total qps is 20
          rule.setQps(20);
          // max parallel working thread is 10
          rule.setMaxThread(10);
  
          SystemRuleManager.loadRules(Collections.singletonList(rule));
      }
  
      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() {
              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 + ", " + TimeUtil.currentTimeMillis() + ", total:"
                      + oneSecondTotal + ", pass:"
                      + oneSecondPass + ", block:" + oneSecondBlock);
                  if (seconds-- <= 0) {
                      stop = true;
                  }
              }
              System.exit(0);
          }
      }
  }
  