Hi, this idea is useful in some ways. When I'm migrating an AngularJS app from $q (a Promise impl) to native async syntax, I got this problem too. But I think this is not the right place to add a "flag" in ES. You may want to suggest V8 or other JS engine to add a flag for it.
On Sun, Apr 26, 2020 at 8:00 PM <[email protected]> wrote: > > Send es-discuss mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://mail.mozilla.org/listinfo/es-discuss > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of es-discuss digest..." > Today's Topics: > > 1. Allow for async/await to use global.Promise and not builtin > Promise (Jake Verbaten) > > > > ---------- Forwarded message ---------- > From: Jake Verbaten <[email protected]> > To: es-discuss <[email protected]> > Cc: > Bcc: > Date: Sun, 26 Apr 2020 10:38:35 +0200 > Subject: Allow for async/await to use global.Promise and not builtin Promise > I've ported a few old fashioned callback code bases to async/await + Promises > in the last year or so. > > When doing performance analysis and profiling I've noticed a significant > negative impact of Promise / async / await in that it adds micro tasks to the > queue. > > Previously there was a different link between the libuv syscall that my > program made in node.js and the actual code being run in my application since > callbacks are called synchronously and there is no micro task queue. > > With the async / await version of the codebase profiling is proving very > challenging because the stack traces all start in the micro task queue. > > Would it be possible with some kind of flag or opt in mechanism to have async > / await use `global.Promise` instead of the builtin native promise ? > > This would allow me to overwrite `global.Promise` with a non-compliant > version that has no micro task queue and invokes all the callbacks > synchronously. This would greatly aid with profiling and stack traces. > > Thank you, > Jake. > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
