Fix orphan extension processes bug

Issue happens after an exception occurs and existing sessions fail to
finish within the timeout period.

lib/extensions.js

@@ -42,19 +42,23 @@ function run(args, callback) {
 
   if (!processes[scriptName]) {
     let p = childProcess.fork('lib/extension-wrapper', [scriptName]);
+    processes[scriptName] = p;
 
     p.on('error', function() {
-      kill(processes[scriptName]);
-      delete processes[scriptName];
+      if (process[scriptName] === p) {
+        kill(processes[scriptName]);
+        delete processes[scriptName];
+      }
     });
 
     p.on('disconnect', function() {
-      kill(processes[scriptName]);
-      delete processes[scriptName];
+      if (process[scriptName] === p) {
+        kill(processes[scriptName]);
+        delete processes[scriptName];
+      }
     });
 
     p.on('message', messageHandler);
-    processes[scriptName] = p;
   }
 
   let id = crypto.randomBytes(8).toString('hex');
@@ -70,7 +74,7 @@ function run(args, callback) {
 };
 
 
-function kill(process) {
+function kill(process, callback) {
   if (process.signalCode !== null || process.exitCode !== null)
     return;
 
@@ -81,18 +85,31 @@ function kill(process) {
   let t = setInterval(function() {
     if (process.signalCode !== null || process.exitCode !== null) {
       clearInterval(t);
+      if (callback)
+        callback();
     }
     else if (Date.now() > timeToKill) {
       process.kill('SIGKILL');
       clearInterval(t);
+      if (callback)
+        callback();
     }
   }, 100);
 }
 
 
-function killAll() {
-  for (let n in processes)
-    kill(processes[n]);
+function killAll(signal, callback) {
+  let counter = 1;
+  for (let n in processes) {
+    ++counter;
+    kill(processes[n], function() {
+      if (--counter == 0 && callback)
+        callback();
+    });
+    delete processes[n];
+  }
+  if (--counter == 0 && callback)
+    callback();
 }
 
 

lib/server.coffee

@@ -41,7 +41,9 @@ server = null
 
 exit = () ->
   setTimeout(() ->
-    process.exit(1)
+    extensions.killAll(() ->
+      process.exit(1)
+    )
   , 30000).unref()
 
   cluster.worker?.disconnect()