Do not restart workers more than once

Author: rmdm

Diff for: lib/worker_wrapper.js

@@ -392,7 +392,7 @@ class WorkerWrapper extends EventEmitterEx {
             // this call of setup sets inspectPort for node js debugger
             // it should be here so that every worker can receive the same debugger port after restarting
             if (this.inspectPort) {
-                this._master.setup({inspectPort: this.inspectPort})
+                this._master.setup({inspectPort: this.inspectPort});
             }
             /** @private */
             this._worker = cluster.fork({
@@ -432,6 +432,7 @@ class WorkerWrapper extends EventEmitterEx {
 
         this.emit('stop');
         this.stopping = true;
+        const stopPid = this._worker && this.pid;
 
         setImmediate(() => {
             // state can be changed before function call
@@ -440,7 +441,8 @@ class WorkerWrapper extends EventEmitterEx {
                     command: RPC.fns.worker.suspend,
                     callback: () => {
                         // Worker could die while suspend was in-flight, i.e. on endless loop, and _onStateStopped will drop _worker
-                        if (this._worker) {
+                        // Or a new one could be started already
+                        if (this._worker && (this.pid === stopPid)) {
                             this._worker.disconnect();
                         }
                     }

Diff for: test/func/fixtures/suspend/master.js

@@ -26,8 +26,8 @@ if (proc.isMaster) {
         case 'register suspend 200':
             proc.remoteCallToAll('register suspend', 200);
             break;
-        case 'register suspend 100000':
-            proc.remoteCallToAll('register suspend', 100000);
+        case 'register suspend 3000':
+            proc.remoteCallToAll('register suspend', 3000);
             break;
         case 'soft-restart':
             pEvent(proc, 'restarted').then(() => process.send('restarted'));

Diff for: test/func/fixtures/suspend/worker.js

@@ -15,3 +15,7 @@ worker.registerRemoteCommand('register suspend', (_, timeout) => {
 worker.on('disconnect', () => {
     console.log('Got disconnect');
 });
+
+worker.on('ready', () => {
+    console.log('Got ready');
+});

Diff for: test/func/test/suspend.js

@@ -14,7 +14,8 @@ describe('suspend before stop', () => {
     it('master calls suspend and waits for it to finish before stop', async () => {
         await instance.sendWaitTimeout('register suspend 100', 10);
         await instance.sendWaitAnswer('soft-restart', 'restarted');
-        const expected = `Waiting 100ms in suspend function
+        const expected = `Got ready
+Waiting 100ms in suspend function
 Finished waiting 100ms in suspend function
 Got disconnect
 `;
@@ -23,15 +24,16 @@ Got disconnect
 
     it('master disconnected worker if no suspend function was registered', async () => {
         await instance.sendWaitAnswer('soft-restart', 'restarted');
-        const expected = 'Got disconnect\n';
+        const expected = 'Got ready\nGot disconnect\n';
         assert.equal(instance.output(), expected);
     });
 
     it('worker waits for all registered suspend functions', async () => {
         await instance.sendWaitTimeout('register suspend 100', 10);
         await instance.sendWaitTimeout('register suspend 200', 10);
         await instance.sendWaitAnswer('soft-restart', 'restarted');
-        const expected = `Waiting 100ms in suspend function
+        const expected = `Got ready
+Waiting 100ms in suspend function
 Waiting 200ms in suspend function
 Finished waiting 100ms in suspend function
 Finished waiting 200ms in suspend function
@@ -41,9 +43,26 @@ Got disconnect
     });
 
     it('master kills worker if suspend did not finish in stopTimeout', async () => {
-        await instance.sendWaitTimeout('register suspend 100000', 10);
+        await instance.sendWaitTimeout('register suspend 3000', 10);
         await instance.sendWaitAnswer('soft-restart', 'restarted');
-        const expected = 'Waiting 100000ms in suspend function\n';
+        const expected = 'Got ready\nWaiting 3000ms in suspend function\n';
+        assert.equal(instance.output(), expected);
+    });
+
+    it('master does not disconnect already killed worker', async function () {
+        // eslint-disable-next-line no-invalid-this
+        this.timeout(15000);
+
+        await instance.sendWaitTimeout('register suspend 3000', 10);
+        await instance.sendWaitAnswer('soft-restart', 'restarted');
+        // No "Got disconnect" is expected
+        const expected = `Got ready
+Waiting 3000ms in suspend function
+Got ready
+`;
+
+        await new Promise(resolve => setTimeout(resolve, 10000));
+
         assert.equal(instance.output(), expected);
     });
 
@@ -53,7 +72,8 @@ Got disconnect
         const exitCode = await instance.sendWaitExit('shutdown');
 
         // Keep those two 'shutting down' to make sure master process got our message and called 'shutdown' twice
-        const expected = `Shutting down
+        const expected = `Got ready
+Shutting down
 Shutting down
 Waiting 100ms in suspend function
 Finished waiting 100ms in suspend function