Implemented infinite loop safety net.

src/Constants.ts

@@ -84,6 +84,7 @@ export const CONSTANTS: {
   SoARepMult: number;
   EntropyEffect: number;
   TotalNumBitNodes: number;
+  InfiniteLoopLimit: number;
   Donations: number; // number of blood/plasma/palette donation the dev have verified., boosts NFG
   LatestUpdate: string;
 } = {
@@ -226,6 +227,8 @@ export const CONSTANTS: {
   // BitNode/Source-File related stuff
   TotalNumBitNodes: 24,
 
+  InfiniteLoopLimit: 1000,
+
   Donations: 7,
 
   LatestUpdate: `

src/GameOptions/ui/CurrentOptionsPage.tsx

@@ -179,6 +179,12 @@ export const CurrentOptionsPage = (props: IProps): React.ReactElement => {
             </>
           }
         />
+        <OptionSwitch
+          checked={Settings.InfinityLoopSafety}
+          onChange={(newValue) => (Settings.InfinityLoopSafety = newValue)}
+          text="Script infinite loop safety net"
+          tooltip={<>If this is set the game will attempt to automatically kill scripts stuck in infinite loops.</>}
+        />
       </GameOptionsPage>
     ),
     [GameOptionsTab.INTERFACE]: (

src/Netscript/APIWrapper.ts

@@ -5,6 +5,8 @@ import type { WorkerScript } from "./WorkerScript";
 import { makeRuntimeRejectMsg } from "../NetscriptEvaluator";
 import { Player } from "../Player";
 import { CityName } from "src/Locations/data/CityNames";
+import { Settings } from "../Settings/Settings";
+import { CONSTANTS } from "../Constants";
 
 type ExternalFunction = (...args: any[]) => any;
 type ExternalAPI = {
@@ -91,8 +93,14 @@ function wrapFunction(
       getValidPort: (port: any) => helpers.getValidPort(functionPath, port),
     },
   };
+  const safetyEnabled = Settings.InfinityLoopSafety;
   function wrappedFunction(...args: unknown[]): unknown {
     helpers.updateDynamicRam(ctx.function, getRamCost(Player, ...tree, ctx.function));
+    if (safetyEnabled) workerScript.infiniteLoopSafetyCounter++;
+    if (workerScript.infiniteLoopSafetyCounter > CONSTANTS.InfiniteLoopLimit)
+      throw new Error(
+        `Infinite loop without sleep detected. ${CONSTANTS.InfiniteLoopLimit} ns functions were called without sleep. This will cause your UI to hang.`,
+      );
     return func(ctx)(...args);
   }
   const parent = getNestedProperty(wrappedAPI, ...tree);

src/Netscript/WorkerScript.ts

@@ -111,6 +111,11 @@ export class WorkerScript {
    */
   atExit: any;
 
+  /**
+   * Once this counter reaches it's limit the script crashes. It is reset when a promise completes.
+   */
+  infiniteLoopSafetyCounter = 0;
+
   constructor(runningScriptObj: RunningScript, pid: number, nsFuncsGenerator?: (ws: WorkerScript) => any) {
     this.name = runningScriptObj.filename;
     this.hostname = runningScriptObj.server;

src/NetscriptEvaluator.ts

@@ -14,6 +14,7 @@ export function netscriptDelay(time: number, workerScript: WorkerScript): Promis
       workerScript.delay = null;
       workerScript.delayReject = undefined;
 
+      workerScript.infiniteLoopSafetyCounter = 0;
       if (workerScript.env.stopFlag) reject(new ScriptDeath(workerScript));
       else resolve();
     }, time);

src/Settings/Settings.ts

@@ -54,6 +54,11 @@ interface IDefaultSettings {
    */
   EnableBashHotkeys: boolean;
 
+  /**
+   * Infinite loop safety net
+   */
+  InfinityLoopSafety: boolean;
+
   /**
    * Timestamps format
    */
@@ -201,6 +206,7 @@ export const defaultSettings: IDefaultSettings = {
   DisableOverviewProgressBars: false,
   EnableBashHotkeys: false,
   TimestampsFormat: "",
+  InfinityLoopSafety: true,
   Locale: "en",
   MaxRecentScriptsCapacity: 50,
   MaxLogCapacity: 50,
@@ -241,6 +247,7 @@ export const Settings: ISettings & ISelfInitializer & ISelfLoading = {
   DisableOverviewProgressBars: defaultSettings.DisableOverviewProgressBars,
   EnableBashHotkeys: defaultSettings.EnableBashHotkeys,
   TimestampsFormat: defaultSettings.TimestampsFormat,
+  InfinityLoopSafety: defaultSettings.InfinityLoopSafety,
   Locale: "en",
   MaxRecentScriptsCapacity: defaultSettings.MaxRecentScriptsCapacity,
   MaxLogCapacity: defaultSettings.MaxLogCapacity,