dnc/manager.js

async function exitHandler(options, exitCode) {
  shutdown().then(()=>{
    setTimeout(function() {
      process.exit();
    }, 1000);
  }).catch(()=>{
    setTimeout(function() {
      process.exit();
    }, 10000);
  });
}
[`SIGINT`, `SIGUSR1`, `SIGUSR2`,`SIGTERM`].forEach((eventType) => {
  process.on(eventType, exitHandler.bind(null, eventType));
});

var shutdownTasks = []

export const addShutdownTask = function(task,maxDuration=5000){
  shutdownTasks.push({t:task,d:maxDuration});
};

export const shutdown = function(){
  return new Promise((res,rej)=>{
    console.log("Shuting down ...");

    var maxDuration = 1000;
    var running = 0;
    var timeout = null;

    function mayShutdown(force=false){
      if(running==0||force){
        if(timeout!=null)clearInterval(timeout);
        res();
      }
    }
    running++;
    for (var i = 0; i < shutdownTasks.length; i++) {
      try {
        if(shutdownTasks[i].d>maxDuration)maxDuration=shutdownTasks[i].d;
        running++;
        let a = shutdownTasks[i].t();
        if(typeof a.then == "function"){
          a.then(()=>{
            running--;
            mayShutdown();
          });
        }else{
          running--;
          if(shutdownTasks.length-1 == i){
            mayShutdown();
          }
        }
      } catch (e) {
        running--;
        mayShutdown();
      }
    }
    running--;
    timeout = setTimeout(function () {
      timeout = null;
      mayShutdown(true);
    }, maxDuration);
    mayShutdown();
  });
};
export const saveShutdown = function(){
  shutdown().then(() => {
    setTimeout(function() { //some save time
      process.exit();
    }, 1000);
  }).catch(() => {
    setTimeout(function() { //shutdown on error with more save time
      process.exit();
    }, 10000);
  });
}