joshLong145
commented
2 months ago @josdejong After some testing of offloaded functions I think there are issues with referencing variables which are defined outside of the offloaded function scope
var workerpool = require('../');
var pool = workerpool.pool();
function asycTimeout() {
return new Promise(function (resolve) {
let timeout = setTimeout(function () {
resolve();
}, 5000);
workerpool.addAbortListener(async function () {
await new Promise((res, rej) => {
setTimeout(res, 1000);
});
clearTimeout(timeout);
resolve();
});
});
};
pool.exec(asycTimeout, [])The above will error with workerpool is not defined. It does not seem like we can define an instance of workerpool within the global if using offloaded functions. I think the only way to support it would be to pass the registration handler to the function.
UPDATE:
After playing around with scopes on the function wrapper from in worker.methods.run I was able to bind addAbortListener to the function itself so it may be accessed with this.addAbortListener
worker.methods.run = function run(fn, args) {
var f = new Function('return (' + fn + ').apply(this, arguments);');
f.addAbortListener = function(listener) {
worker.abortListeners.push(listener);
}
return f.apply(f, args);
};If we modify the global value to this instead of null we can then modify the f object to provide the addEventListener context. this is hacky but does now allow for a unique this context from within an offloaded function
we still have access to the global through globalThis below is an example of an offloaded function which uses the above modified run implementation
var workerpool = require('../');
var pool = workerpool.pool();
function asycTimeout() {
var me = this;
return new Promise(function (resolve) {
let timeout = setTimeout(function () {
resolve();
}, 5000);
console.log(me.addAbortListener, globalThis);
me.addAbortListener(async function () {
console.log("adasd", clearTimeout);
clearTimeout(timeout);
resolve();
});
});
};
pool.exec(asycTimeout, [])
josdejong
Adds an
abortListenerto workers which allow for cleanup of async tasks which can be run as a cleanup operation to allow workers to be reused if a task timeout or cancellation occurs.connects PR #441