Add support for running extensions in the browser

src/node/ipc.ts

@@ -0,0 +1,52 @@
+import * as cp from "child_process";
+import { Emitter } from "vs/base/common/event";
+
+enum ControlMessage {
+	okToChild = "ok>",
+	okFromChild = "ok<",
+}
+
+export type Message = "relaunch";
+
+class IpcMain {
+	protected readonly _onMessage = new Emitter<Message>();
+	public readonly onMessage = this._onMessage.event;
+
+	public handshake(child?: cp.ChildProcess): Promise<void> {
+		return new Promise((resolve, reject) => {
+			const target = child || process;
+			if (!target.send) {
+				throw new Error("Not spawned with IPC enabled");
+			}
+			target.on("message", (message) => {
+				if (message === child ? ControlMessage.okFromChild : ControlMessage.okToChild) {
+					target.removeAllListeners();
+					target.on("message", (msg) => this._onMessage.fire(msg));
+					if (child) {
+						target.send!(ControlMessage.okToChild);
+					}
+					resolve();
+				}
+			});
+			if (child) {
+				child.once("error", reject);
+				child.once("exit", (code) => {
+					const error = new Error(`Unexpected exit with code ${code}`);
+					(error as any).code = code;
+					reject(error);
+				});
+			} else {
+				target.send(ControlMessage.okFromChild);
+			}
+		});
+	}
+
+	public relaunch(): void {
+		if (!process.send) {
+			throw new Error("Not a child process with IPC enabled");
+		}
+		process.send("relaunch");
+	}
+}
+
+export const ipcMain = new IpcMain();