test('buffered sending - lots of data (potential deadlock on win32)', function (done: () => void) {
		if (!platform.isWindows || process.env['VSCODE_PID']) {
			return done(); // test is only relevant for Windows and seems to crash randomly on some Linux builds
		}

		const child = fork('vs/base/test/node/processes/fixtures/fork_large');
		const sender = processes.createQueuedSender(child);

		const largeObj = Object.create(null);
		for (let i = 0; i < 10000; i++) {
			largeObj[i] = 'some data';
		}

		const msg = JSON.stringify(largeObj);
		child.on('message', msgFromChild => {
			if (msgFromChild === 'ready') {
				sender.send(msg);
				sender.send(msg);
				sender.send(msg);
			} else if (msgFromChild === 'done') {
				child.kill();
				done();
			}
		});
	});

	private get client(): IPCClient {
		if (!this._client) {
			const args = this.options && this.options.args ? this.options.args : [];
			const forkOpts = Object.create(null);

			forkOpts.env = assign(clone(process.env), { 'VSCODE_PARENT_PID': String(process.pid) });

			if (this.options && this.options.env) {
				forkOpts.env = assign(forkOpts.env, this.options.env);
			}

			if (this.options && this.options.freshExecArgv) {
				forkOpts.execArgv = [];
			}

			if (this.options && typeof this.options.debug === 'number') {
				forkOpts.execArgv = ['--nolazy', '--debug=' + this.options.debug];
			}

			if (this.options && typeof this.options.debugBrk === 'number') {
				forkOpts.execArgv = ['--nolazy', '--debug-brk=' + this.options.debugBrk];
			}

			this.child = fork(this.modulePath, args, forkOpts);

			const onMessageEmitter = new Emitter<any>();
			const onRawMessage = fromEventEmitter(this.child, 'message', msg => msg);

			onRawMessage(msg => {
				// Handle console logs specially
				if (msg && msg.type === '__$console') {
					let args = ['%c[IPC Library: ' + this.options.serverName + ']', 'color: darkgreen'];
					try {
						const parsed = JSON.parse(msg.arguments);
						args = args.concat(Object.getOwnPropertyNames(parsed).map(o => parsed[o]));
					} catch (error) {
						args.push(msg.arguments);
					}

					console[msg.severity].apply(console, args);
					return null;
				}

				// Anything else goes to the outside
				else {
					onMessageEmitter.fire(msg);
				}
			});

			const sender = this.options.useQueue ? createQueuedSender(this.child) : this.child;
			const send = r => this.child && this.child.connected && sender.send(r);
			const onMessage = onMessageEmitter.event;
			const protocol = { send, onMessage };

			this._client = new IPCClient(protocol);

			const onExit = () => this.disposeClient();
			process.once('exit', onExit);

			this.child.on('error', err => console.warn('IPC "' + this.options.serverName + '" errored with ' + err));

			this.child.on('exit', (code: any, signal: any) => {
				process.removeListener('exit', onExit);

				if (this.activeRequests) {
					this.activeRequests.forEach(req => req.cancel());
					this.activeRequests = [];
				}

				if (code !== 0 && signal !== 'SIGTERM') {
					console.warn('IPC "' + this.options.serverName + '" crashed with exit code ' + code);
					this.disposeDelayer.cancel();
					this.disposeClient();
				}
			});
		}

		return this._client;
	}

	private get client(): IPCClient {
		if (!this._client) {
			const args = this.options && this.options.args ? this.options.args : [];
			const forkOpts: ForkOptions = Object.create(null);

			forkOpts.env = assign(deepClone(process.env), { 'VSCODE_PARENT_PID': String(process.pid) });

			if (this.options && this.options.env) {
				forkOpts.env = assign(forkOpts.env, this.options.env);
			}

			if (this.options && this.options.freshExecArgv) {
				forkOpts.execArgv = [];
			}

			if (this.options && typeof this.options.debug === 'number') {
				forkOpts.execArgv = ['--nolazy', '--inspect=' + this.options.debug];
			}

			if (this.options && typeof this.options.debugBrk === 'number') {
				forkOpts.execArgv = ['--nolazy', '--inspect-brk=' + this.options.debugBrk];
			}

			this.child = fork(this.modulePath, args, forkOpts);

			const onMessageEmitter = new Emitter<any>();
			const onRawMessage = fromNodeEventEmitter(this.child, 'message', msg => msg);

			onRawMessage(msg => {

				// Handle remote console logs specially
				if (isRemoteConsoleLog(msg)) {
					log(msg, `IPC Library: ${this.options.serverName}`);
					return null;
				}

				// Anything else goes to the outside
				onMessageEmitter.fire(msg);
			});

			const sender = this.options.useQueue ? createQueuedSender(this.child) : this.child;
			const send = r => this.child && this.child.connected && sender.send(r);
			const onMessage = onMessageEmitter.event;
			const protocol = { send, onMessage };

			this._client = new IPCClient(protocol);

			const onExit = () => this.disposeClient();
			process.once('exit', onExit);

			this.child.on('error', err => console.warn('IPC "' + this.options.serverName + '" errored with ' + err));

			this.child.on('exit', (code: any, signal: any) => {
				process.removeListener('exit', onExit);

				if (this.activeRequests) {
					this.activeRequests.forEach(req => req.cancel());
					this.activeRequests = [];
				}

				if (code !== 0 && signal !== 'SIGTERM') {
					console.warn('IPC "' + this.options.serverName + '" crashed with exit code ' + code + ' and signal ' + signal);
					this.disposeDelayer.cancel();
					this.disposeClient();
				}
			});
		}

		return this._client;
	}

	initData: IInitData;
}

/**
 * Flag set when in shutdown phase to avoid communicating to the main process.
 */
let isTerminating = false;

// This calls exit directly in case the initialization is not finished and we need to exit
// Otherwise, if initialization completed we go to extensionHostMain.terminate()
let onTerminate = function () {
	exit();
};

// Utility to not flood the process.send() with messages if it is busy catching up
const queuedSender = createQueuedSender(process);

function connectToRenderer(): TPromise<IRendererConnection> {
	return new TPromise<IRendererConnection>((c, e) => {
		const stats: number[] = [];

		// Listen init data message
		process.once('message', raw => {

			let msg = marshalling.parse(raw);

			const remoteCom = createIPC(data => {
				// Needed to avoid EPIPE errors in process.send below when a channel is closed
				if (isTerminating === true) {
					return;
				}