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Three ways of handling user input

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Re: Three ways of handling user input

#11

Post by ianbicking »

jayd16 wrote: post #5
kevmo314 wrote: post #3

Does anyone else find approach #3 to be wildly unintuitive? Like how does an infinite loop terminate? There's a lot of magic going on. I like approach #1 the best. Sure, there are some bugs, but a state diagram would help make it clearer instead of introducing magic.

Its not that unintuitive once you understand async/await and how the tasks are resumed. Execution is yielded at an await. At that time the loop is not running anywhere, its not even in a sleep state. The loop "terminates" by never being resumed.

I'm assuming the loop would terminate with an exception... like `await events.pointermove` would raise some cancellation exception that would be silently captured.

Re: Three ways of handling user input

#12

Post by jayd16 »

bruce343434 wrote: post #9
jayd16 wrote: post #5

Earlier quoted context omitted.

Its not that unintuitive once you understand async/await and how the tasks are resumed. Execution is yielded at an await. At that time the loop is not running anywhere, its not even in a sleep state. The loop "terminates" by never being resumed.

Wouldn't that result in a thread leak? (Or a "fiber" leak)

If a task has yielded its not holding on to a thread. A loop that wasn't yielding would leak, though.

Re: Three ways of handling user input

#13

Post by jayd16 »

ianbicking wrote: post #11
jayd16 wrote: post #5

Earlier quoted context omitted.

Its not that unintuitive once you understand async/await and how the tasks are resumed. Execution is yielded at an await. At that time the loop is not running anywhere, its not even in a sleep state. The loop "terminates" by never being resumed.

I'm assuming the loop would terminate with an exception... like `await events.pointermove` would raise some cancellation exception that would be silently captured.

Sounds like the Abro runtime never resumes the tasks so how could they throw?

Re: Three ways of handling user input

#14

Post by jayd16 »

xupybd wrote: post #6
jayd16 wrote: post #5

Earlier quoted context omitted.

Its not that unintuitive once you understand async/await and how the tasks are resumed. Execution is yielded at an await. At that time the loop is not running anywhere, its not even in a sleep state. The loop "terminates" by never being resumed.

Yeah that's still not the way the code reads. The closer the code behaves to the way it reads the better in my book.

How does it read to you?

Re: Three ways of handling user input

#15

Post by ianbicking »

jayd16 wrote: post #13
ianbicking wrote: post #11

Earlier quoted context omitted.

I'm assuming the loop would terminate with an exception... like `await events.pointermove` would raise some cancellation exception that would be silently captured.

Sounds like the Abro runtime never resumes the tasks so how could they throw?

Oh... on second thought I realize the exception would have to come from `event.pointermove` (for example), and that object doesn't know anything about the receiver or whether it should cancel. So yeah, this does seem problematic.

Re: Three ways of handling user input

#16

Post by jayd16 »

ianbicking wrote: post #15
jayd16 wrote: post #13

Earlier quoted context omitted.

Sounds like the Abro runtime never resumes the tasks so how could they throw?

Oh... on second thought I realize the exception would have to come from `event.pointermove` (for example), and that object doesn't know anything about the receiver or whether it should cancel. So yeah, this does seem problematic.

Are you worried about when the case when an exception should be thrown from the thing being awaited? I'm not familiar with Arbo but usually the promise holds on to the exception until its observed. It could be that Arbo is configured to ignore the exception if the task is already cancelled.

Re: Three ways of handling user input

#17

Post by rexpan »

jayd16 wrote: post #13
ianbicking wrote: post #11

Earlier quoted context omitted.

I'm assuming the loop would terminate with an exception... like `await events.pointermove` would raise some cancellation exception that would be silently captured.

Sounds like the Abro runtime never resumes the tasks so how could they throw?

These 3 functions will stop on `await event.xxx` (if not, they will continue to execute or terminate). So when one of the functions is terminate https://github.com/pdubroy/handling-user-input/blob/main/abr...

   await Promise.any(fibers.map((f) => f.run()));
   fibers.forEach((f) => f.terminate());
Abro will reject the promise of these `await event.xxx` https://github.com/pdubroy/handling-user-input/blob/main/abr...

    this._promises.forEach(({ reject }) => reject());
Which will throw an Exception and exit the 2 other functions.
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