vm: Add timeout

jsc/vm/call.ts

@@ -25,6 +25,7 @@ import { Scope } from "./scope";
 import { ByteCode, byteCodeArgSize } from "../src/bytecode";
 import { Obj } from "./obj";
 import { compiler } from "./compiler";
+import { timer } from "./timer";
 
 export function call(callable: Value, env: Value, args: Value[] = []): Value {
   if (!isCallable(callable)) {
@@ -42,13 +43,14 @@ export function exec(
   data: CompiledData,
   callScope: Scope,
   env: Value,
-  args: Value[] = []
+  args: Value[] = [],
+  dataStack: DataStack = new DataStack()
 ): Value {
-  const dataStack = new DataStack();
   const { codeSection, constantPool, scope } = data;
   let cursor = 0;
 
   while (cursor < codeSection.size) {
+    timer.check();
     const bytecode = codeSection.get(cursor) as ByteCode;
     const argsSize = byteCodeArgSize[bytecode] || 0;
     let nextCursor = cursor + argsSize + 1;
@@ -426,9 +428,6 @@ export function exec(
         dataStack.push(ret);
         break;
       }
-
-      default:
-        console.log("TODO: " + ByteCode[bytecode]);
     }
     cursor = nextCursor;
   }

jsc/vm/ds.ts

@@ -9,7 +9,11 @@
 import { Data } from "./data";
 
 export class DataStack {
-  private stack: Data[] = [];
+  private readonly stack: Data[] = [];
+
+  getSize(): number {
+    return this.stack.length;
+  }
 
   push(value: Data): void {
     this.stack.push(value);

jsc/vm/timer.ts

@@ -0,0 +1,18 @@
+class Timer {
+  private timeout = -1;
+  private currentStart = 0;
+
+  check(): void {
+    if (this.timeout < 0) return;
+
+    if (Date.now() - this.currentStart > this.timeout)
+      throw new Error("Timeout");
+  }
+
+  start(timeout: number): void {
+    this.currentStart = Date.now();
+    this.timeout = timeout;
+  }
+}
+
+export const timer = new Timer();

jsc/vm/vm.ts

@@ -10,16 +10,30 @@ import { Scope } from "./scope";
 import { exec } from "./call";
 import { Value } from "./data";
 import { compiler } from "./compiler";
+import { DataStack } from "./ds";
+import { timer } from "./timer";
+
+export interface VMOptions {
+  timeout: number;
+}
 
 export class VM {
-  private scope: Scope = new Scope(false);
+  readonly scope: Scope = new Scope(false);
+  readonly dataStack: DataStack = new DataStack();
+  readonly timeout: number;
+
+  constructor(options?: VMOptions) {
+    options = {
+      timeout: -1,
+      ...options
+    };
+
+    this.timeout = options.timeout;
+  }
 
   compileAndExec(source: string): Value {
     const main = compiler.compile(source);
-
-    console.time("exec");
-    const ret = exec(main, this.scope, this.scope.obj, []);
-    console.timeEnd("exec");
-    return ret;
+    timer.start(this.timeout);
+    return exec(main, this.scope, this.scope.obj, [], this.dataStack);
   }
 }