'use strict'; require('../common'); const vm = require('vm'); // We're testing a race condition so we just have to spin this in a loop // for a little while and see if it breaks. The condition being tested // is an `isolate->TerminateExecution()` reaching the main JS stack from // the timeout watchdog. const sandbox = { timeout: 5 }; const context = vm.createContext(sandbox); const script = new vm.Script( 'var d = Date.now() + timeout;while (d > Date.now());' ); const immediate = setImmediate(function() { throw new Error('Detected vm race condition!'); }); // When this condition was first discovered this test would fail in 50ms // or so. A better, but still incorrect implementation would fail after // 100 seconds or so. If you're messing with vm timeouts you might // consider increasing this timeout to hammer out races. const giveUp = Date.now() + 5000; do { // The loop adjusts the timeout up or down trying to hit the race try { script.runInContext(context, { timeout: 5 }); ++sandbox.timeout; } catch (err) { --sandbox.timeout; } } while (Date.now() < giveUp); clearImmediate(immediate);