Ultimately speaking - is there a practical method (also maybe by inserting some JS constructs into the code) to break or halt the long lasting JS code during the execution? For example: can it be interrupted by some process.*
object constructs, or similar? Or the other way? The valid solution may even include the NodeJS process to be killed and/or restarted. Thank you!
EDIT:
I need to execute some particular user code on the server, using Function
clause (ala eval
, - let alone security concerns). I cannot insert any extra code inside it, only enclose it. What I need is to have a possibility to break user code after 5 minutes, if it is not finished by this time. For example:
usercode = 'Some code from the user';
pre_code = 'some controlling code for breaking the user code';
post_code = 'another controlling code';
fcode = pre_code + usercode + post_code;
<preparations for breaking usercode>
(new Function(fcode))(); // This MUST exit in 5 minutes
Edit:
Answering your edit. I see the intention now. If it is running in nodejs, you can use worker_thread for that https://nodejs.org/api/worker_threads.html#worker_threads_worker_workerdata.
For example:
// main.js
const runCode = (code) => {
const worker = new Worker("./code-executor.js", { workerData: { code: guestCode } });
const promise = new Promise((resolve) => {
setTimeout(() => worker.kill(), 60000 * 5);
worker.on("error", () => {
return reject(new SomeCustomError())
});
worker.on("message", (message) => {
if(message.success) return resolve(message.result);
return reject(new Error(message.error));
});
});
promise.finally(() => { worker.kill() });
return promise;
}
// code-executor.js
const { workerData, parentPort } = require("worker_threads");
const { code } = workerData;
Promise.resolve()
.then(() => (new Function(fcode))())
.then((result) => {
parentPort.postMessage({
success: true,
result: value
})
})
.catch((error) => {
parentPort.postMessage({
success: true,
error: error.message
})
});
If it's in browser https://developer.mozilla.org/en-US/docs/Web/API/Worker The WebAPI is not exactly the same but the logic should be similar
Original
Killing a process. Also read: https://nodejs.org/api/process.html#process_signal_events
process.kill(pid, "SIGINT")
"Killing" a long running function, you gotta hack a bit. There's no elegant solution. Inject a controller which can be mutated outside of the long running function. To stop it from the outside, set controller.isStopped = true
export const STOP_EXECUTION = Symbol();
function longRunning(controller){
... codes
// add stopping point
if(controller.isStopped) throw STOP_EXECUTION;
... codes
// add stopping point
if(controller.isStopped) throw STOP_EXECUTION;
... codes
}
// catch it by
try{
longRunnning();
}catch(e){
switch(true){
e === STOP_EXECUTION: ...; // the longRunning function is stopped from the outside
default: ...; // the longRunning function is throwing not because of being stopped
}
}
Gist: https://gist.github.com/Kelerchian/3824ca4ce1be390d34c5147db671cc9b