Graceful shutdown (#583)

README.md

@@ -233,6 +233,22 @@ const job = schedule.scheduleJob({ start: startTime, end: endTime, rule: '*/1 *
 });
 ```
 
+### Graceful Shutdown.
+You can shutdown jobs gracefully.  
+`gracefulShutdown()` will cancel all jobs and return Promise.  
+It will wait until all jobs are terminated.  
+```js
+schedule.gracefulShutdown();
+```
+
+You can also gracefully shutdown jobs when a system interrupt occurs.
+```
+process.on('SIGINT', function () { 
+  schedule.gracefulShutdown()
+  .then(() => process.exit(0))
+}
+```
+
 ### Handle Jobs and Job Invocations
 
 There are some function to get information for a Job and to handle the Job and

index.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const { cancelJob, rescheduleJob, scheduledJobs, scheduleJob} = require('./lib/schedule')
+const { cancelJob, rescheduleJob, scheduledJobs, scheduleJob, gracefulShutdown} = require('./lib/schedule')
 const { Invocation, RecurrenceRule, Range} = require('./lib/Invocation')
 const { Job } = require('./lib/Job')
 
@@ -12,5 +12,6 @@ module.exports = {
   cancelJob,
   rescheduleJob,
   scheduledJobs,
-  scheduleJob
+  scheduleJob,
+  gracefulShutdown,
 }

lib/Invocation.js

@@ -267,19 +267,23 @@ function prepareNextInvocation() {
       try {
         const result = job.invoke(cinv.fireDate instanceof CronDate ? cinv.fireDate.toDate() : cinv.fireDate);
         job.emit('run');
+        job.running += 1;
 
         if (result instanceof Promise) {
-          result.then(function(value) {
+          result.then(function (value) {
             job.emit('success', value);
-          })
-            .catch(function (err) {
-              job.emit('error', err);
-            });
+            job.running -= 1;
+          }).catch(function (err) {
+            job.emit('error', err);
+            job.running -= 1;
+          });
         } else {
           job.emit('success', result);
+          job.running -= 1;
         }
       } catch (err) {
         job.emit('error', err);
+        job.running -= 1;
       }
 
       if (job.isOneTimeJob) {

lib/Job.js

@@ -41,6 +41,9 @@ function Job(name, job, callback) {
     this.callback = typeof callback === 'function' ? callback : false;
   }
 
+  // task count
+  this.running = 0;
+
   // Check for generator
   if (typeof this.job === 'function' &&
     this.job.prototype &&

lib/schedule.js

@@ -73,10 +73,42 @@ function cancelJob(job) {
   return success;
 }
 
+function gracefulShutdown() {
+  const jobs = Object.keys(scheduledJobs).map(key => scheduledJobs[key]);
+  jobs.forEach(function (job) {
+    job.cancel();
+  });
+
+  let running = false;
+  for (let i = 0; i < jobs.length; i++) {
+    if (jobs[i].running > 0) {
+      running = true;
+      break;
+    }
+  }
+
+  return new Promise(function (resolve) {
+    if (running) {
+      setInterval(function () {
+        for (let i = 0; i < jobs.length; i++) {
+          if (jobs[i].running > 0) {
+            return;
+          }
+        }
+
+        resolve();
+      }, 500);
+    } else {
+      resolve();
+    }
+  });
+}
+
 /* Public API */
 module.exports = {
   scheduleJob,
   rescheduleJob,
   scheduledJobs,
-  cancelJob
+  cancelJob,
+  gracefulShutdown,
 }

test/graceful-shutdown-test.js

@@ -0,0 +1,23 @@
+'use strict';
+
+const test = require('tape');
+const schedule = require('..');
+
+test('Graceful Shutdown', function (t) {
+  t.test('pending when job running', function (test) {
+    test.plan(1);
+    const job = schedule.scheduleJob('* * * * * *', function () {
+    });
+
+    job.running = 1;
+    schedule.gracefulShutdown().then(function() {
+      test.ok(true);
+    });
+
+    job.running = 0;
+    schedule.gracefulShutdown().then(function() {
+      test.ok(true);
+      test.end();
+    });
+  });
+});