lib: fix cluster handle leak

It is possible to cause a resource leak in SharedHandle. This commit
fixes the leak.
Fixes: #2510
PR-URL: #3510
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

Author: Trott

lib/cluster.js

@@ -345,7 +345,10 @@ function masterInit() {
  * if it has disconnected, otherwise we might
  * still want to access it.
  */
-if(!worker.isConnected())removeWorker(worker);
+if(!worker.isConnected()){
+removeHandlesForWorker(worker);
+removeWorker(worker);
+}
 
 worker.suicide=!!worker.suicide;
 worker.state='dead';

test/parallel/test-cluster-shared-leak.js

@@ -0,0 +1,53 @@
+// In Node 4.2.1 on operating systems other than Linux, this test triggers an
+// assertion in cluster.js. The assertion protects against memory leaks.
+// https://github.com/nodejs/node/pull/3510
+
+'use strict';
+constcommon=require('../common');
+constassert=require('assert');
+constnet=require('net');
+constcluster=require('cluster');
+cluster.schedulingPolicy=cluster.SCHED_NONE;
+
+if(cluster.isMaster){
+varconn,worker1,worker2;
+
+worker1=cluster.fork();
+worker1.on('message',common.mustCall(function(){
+worker2=cluster.fork();
+conn=net.connect(common.PORT,common.mustCall(function(){
+worker1.send('die');
+worker2.send('die');
+}));
+conn.on('error',function(e){
+// ECONNRESET is OK
+if(e.code!=='ECONNRESET')
+throwe;
+});
+}));
+
+cluster.on('exit',function(worker,exitCode,signalCode){
+assert(worker===worker1||worker===worker2);
+assert.strictEqual(exitCode,0);
+assert.strictEqual(signalCode,null);
+if(Object.keys(cluster.workers).length===0)
+conn.destroy();
+});
+
+return;
+}
+
+varserver=net.createServer(function(c){
+c.end('bye');
+});
+
+server.listen(common.PORT,function(){
+process.send('listening');
+});
+
+process.on('message',function(msg){
+if(msg!=='die')return;
+server.close(function(){
+setImmediate(()=>process.disconnect());
+});
+});