Await completed Tasks on the same thread. #11142
Merged
Conversation
This file contains hidden or 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
Fixes dotnet#9685. Besides passing ExecuteSynchronously, if the task is already completed, the continuation is directly invoked, bypassing Task.ContinueWith. Such trick is also performed by Roslyn.
dsyme
reviewed
Feb 25, 2021
teo-tsirpanis
force-pushed
the
fix-9685
branch
from
d3d263e to
f753263
Compare
dsyme
approved these changes
Feb 25, 2021
Contributor
dsyme
left a comment
dsyme
left a comment
There was a problem hiding this comment.
One minor change requestedremoving a comment
KevinRansom
approved these changes
Feb 25, 2021
cartermp
approved these changes
Feb 25, 2021
Contributor
|
@teo-tsirpanis This caused a regression, see #11797. The change here installs a new trampoline on each completed task continuation - no new trampoline should be installed when we detect synchronous completion. I'll push a PR with the fix |
This was referenced Jul 8, 2021
Merged
Contributor
|
It looks like this PR causes other problems beyond #11797, through the use of ExecuteSynchronously clag on this line: https://github.com/dotnet/fsharp/pull/11142/files#diff-7330c080710da91733bbc5e1b5bdae30f4adf528f7847efbac3d86a0d4132b1dR945 I will remove that, this flag is not necessary for the asynchronous case, since we are already checking for synchronous completion. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
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Outdated suggestions cannot be applied.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.
This PR fixes #9685 by both setting a
TaskContinuationFlags.RunSynchronouslywhen attaching a continuation on theTasks and by avoiding setting the continuation altogether when the task is completed.The issue's title's "never" is now changed to "only when there is no sufficient stack", in which case the trampoline will take over.
Finally, the PR uses
Thread.IsThreadPoolThreadin one occasion it should.