fixing caching of cancelled cached tasks #1221
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
TheAngryByrd
commented
Jan 14, 2024
Comment on lines
30
to
41
| type TaskCompletionSource<'a> with | ||
| /// https://github.com/dotnet/runtime/issues/47998 | ||
| member tcs.TrySetFromTask(real : Task<'a>) = | ||
| task { | ||
| try | ||
| let! r = real | ||
| tcs.TrySetResult r |> ignore<bool> | ||
| with | ||
| | :? OperationCanceledException as x -> tcs.TrySetCanceled(x.CancellationToken) |> ignore<bool> | ||
| | ex -> tcs.TrySetException ex |> ignore<bool> | ||
| } | ||
| |> ignore<Task<unit>> |
There was a problem hiding this comment.
Refactoring of the ContinueWith style in the previous version
| cached <- | ||
| match cached with | ||
| | null -> createCached () | ||
| | x when x.IsCompleted && not real.IsCompleted -> |
Comment on lines
-578
to
-581
| let! ct = CancellableTask.getCancellationToken () | ||
| let it = input.GetValue t | ||
| use _s = ct.Register(fun () -> it.Cancel()) | ||
| let! i = it |
There was a problem hiding this comment.
Most of this stuff is happening with the extension methods that use https://github.com/fsharp/FsAutoComplete/blob/9494bbf9554844dde4dcb740cd2839c6d507e414/src/FsAutoComplete.Core/AdaptiveExtensions.fs#L403-L408
TheAngryByrd
force-pushed
the
fixing-annoying-cached-cancelled-tasks
branch
from
dd5290d
to
921b5e1
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Primer
The way the AsyncAdaptive is implemented using ref-counting for tasks that depend on tasks. So if a dependent task (let's say getting a type signature hint) asks for a currently running task's result (like a typecheck) but it isn't finished, we create a
TaskCompletionSourceand transfer state to it when the "real" task is finished. This allows us to have to have many dependent sources still awaiting the typecheck (like say a codefix) but allows us to cancel the hint request if the user's mouse moves away.Main problem is we were caching those cancelled tasks while the real task may still be running. Since no updates happened, Adaptive wouldn't mark the dependent tree out of date and forever getting "Task was cancelled" in places we should recompute.