Refactored child process management

davidmerfield · Oct 10, 2018 · 213ee02 · 213ee02
1 parent 6f91b66
commit 213ee02
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Showing 4 changed files with 65 additions and 80 deletions.
diff --git a/app/build/index.js b/app/build/index.js
@@ -7,14 +7,21 @@ var Prepare = require("./prepare");
 var Thumbnail = require("./thumbnail");
 var DateStamp = require("./prepare/dateStamp");
 var moment = require("moment");
-var converters = require('./converters');
+var converters = require("./converters");
+
+var exitHook = require("async-exit-hook");
 
 process.on("message", function(message) {
   build(message.blog, message.path, message.options, function(err, entry) {
     process.send({ err: err, entry: entry, id: message.id });
   });
 });
 
+console.log("Started build:", process.pid);
+
+exitHook(function() {
+  console.log("Shutting down build:", process.pid);
+});
 
 // This file cannot become a blog post because it is not
 // a type that Blot can process properly.
@@ -28,12 +35,10 @@ function isWrongType(path) {
   return isWrong;
 }
 
-
 function build(blog, path, options, callback) {
-
   if (isWrongType(path)) {
-    var err = new Error('Path is wrong type to convert');
-    err.code = 'WRONGTYPE';
+    var err = new Error("Path is wrong type to convert");
+    err.code = "WRONGTYPE";
     return callback(err);
   }
 
@@ -105,4 +110,4 @@ function build(blog, path, options, callback) {
   });
 }
 
-module.exports = build;
+module.exports = build;
diff --git a/app/sync/index.js b/app/sync/index.js
@@ -19,14 +19,6 @@ var DEFAULT_TTL = 10 * 60 * 1000;
 var locks = {};
 
 exitHook(function(callback) {
-  unlock(callback);
-});
-
-exitHook.uncaughtExceptionHandler(function(err, callback) {
-  unlock(callback);
-});
-
-function unlock(callback) {
   console.log("Unlocking all locks...");
 
   async.eachOf(
@@ -35,12 +27,14 @@ function unlock(callback) {
       console.log("Unlocking", blogID, "...");
       lock.unlock(next);
     },
-    function(){
-      console.log('Unlocked all locks...');
-      callback();
-    }
+    callback
   );
-}
+});
+
+// exitHook.uncaughtExceptionHandler(function(err, callback) {
+//   unlock(callback);
+// });
+
 function sync(blogID, options, callback) {
   var redlock, resource, ttl, folder;
 

diff --git a/app/sync/tests/index.js b/app/sync/tests/index.js
@@ -30,7 +30,7 @@ describe("sync", function() {
     });
   });
 
-  xit("will release a lock when the process dies due to an uncaught exception", function(testDone) {
+  it("will release a lock when the process dies due to an uncaught exception", function(testDone) {
     var child = require("child_process").fork(__dirname + "/error", {silent: true});
     var blog = this.blog;
 

diff --git a/app/sync/update/set.js b/app/sync/update/set.js
@@ -21,66 +21,52 @@ function isTemplate(path) {
   return normalize(path).indexOf("/templates/") === 0;
 }
 
-// var child_process = require("child_process");
-// var numCPUs = require("os").cpus().length;
-// var uuid = require("uuid/v4");
-// var exitHook = require("async-exit-hook");
-
-// exitHook(function(callback) {
-//   killWorkers(callback);
-// });
-
-// exitHook.uncaughtExceptionHandler(function(err, callback) {
-//   killWorkers(callback);
-// });
-
-// function killWorkers(callback) {
-//   console.log("Unlocking all locks...");
-
-//   async.each(
-//     workers,
-//     function(worker, next) {
-//       console.log("Killing worker...");
-//       worker.kill();
-//       next();
-//     },
-//     function() {
-//       console.log("Killed all workers...");
-//       callback();
-//     }
-//   );
-// }
-
-// var workers = [];
-// var worker;
-// var jobs = {};
-
-// function triggerCallback(message) {
-//   jobs[message.id].callback(message.err, message.entry);
-// }
-
-// for (var i = 0; i < numCPUs; i++) {
-//   worker = child_process.fork(__dirname + "/../../build");
-//   worker.on("message", triggerCallback);
-//   workers.push(worker);
-// }
-
-// function build(blog, path, options, callback) {
-//   var worker = workers[Math.floor(Math.random() * workers.length)];
-//   var id = uuid();
-
-//   jobs[id] = {
-//     blog: blog,
-//     id: id,
-//     path: path,
-//     options: options,
-//     callback: callback
-//   };
-
-//   worker.send({ blog: blog, path: path, id: id, options: options });
-// }
-
-var build = require('../../build');
+var child_process = require("child_process");
+var numCPUs = require("os").cpus().length;
+var uuid = require("uuid/v4");
+var exitHook = require("async-exit-hook");
+
+var workers = [];
+var worker;
+var jobs = {};
+
+
+exitHook(killWorkers);
+
+function killWorkers() {
+  console.log("Unlocking all locks...");
+  workers.forEach(function(worker){
+    worker.kill();
+  });
+}
+
+
+function triggerCallback(message) {
+  jobs[message.id].callback(message.err, message.entry);
+}
+
+for (var i = 0; i < numCPUs; i++) {
+  worker = child_process.fork(__dirname + "/../../build");
+  worker.on("message", triggerCallback);
+  workers.push(worker);
+}
+
+function build(blog, path, options, callback) {
+  var worker = workers[Math.floor(Math.random() * workers.length)];
+  var id = uuid();
+
+  jobs[id] = {
+    blog: blog,
+    id: id,
+    path: path,
+    options: options,
+    callback: callback
+  };
+
+  worker.send({ blog: blog, path: path, id: id, options: options });
+}
+
+// var build = require('../../build');
 
 module.exports = function(blog, path, options, callback) {
   var queue;