Switch to using DispatchWorkItem for cancelation #24
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
… there was a small queue-order issue that was making tests accidentally succeed)
jake-iheart
approved these changes
Apr 12, 2020
| DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 0.1) { | ||
| token.cancel() | ||
| } | ||
| self.wait(for: [expectation], timeout: 0.5) | ||
| } | ||
|
|
||
| func testCancelPromiseAfterFulfilment() { |
mvyrko
reviewed
Apr 12, 2020
| self.onCancel = wrappedBlock | ||
| } | ||
| if let workItem = workItem { | ||
| let cancelItem = DispatchWorkItem(block: onCancel) |
There was a problem hiding this comment.
I suggest to use enforceQoS: DispatchWorkItemFlags it should increase priority for cancelation tasks.
There was a problem hiding this comment.
inheritQoS would be better don't you think
There was a problem hiding this comment.
as far as I understand these very similar flags they increase priority for tasks:
static let enforceQoS: DispatchWorkItemFlags
//Prefer the quality-of-service class associated with the block.
static let inheritQoS: DispatchWorkItemFlags
//Prefer the quality-of-service class associated with the current execution context.Here we work with blocks then we should use enforceQoS.
There was a problem hiding this comment.
nah, it shouldn't raise the priority of the queue and indirectly other tasks? if its inherit, then its own qos can be raised to a higher one if the queue specifies it. But otherwise no.
chow-land
approved these changes
Apr 13, 2020
| } | ||
|
|
||
| case .promise(let promise): | ||
| if self.cancelFlag.isCanceled { | ||
| if self.isCanceled { |
|
@benski @chow-land @mvyrko just like old times 👍 |
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.
The implementation of
AtomicCancelcould not be verified by static or runtime analysis. As an alternative, I've switched the underlying implementation to use DispatchWorkItem.All the tests pass fine, and I added some short dispatch_after delays to make sure that the tests weren't false positives.
In the future, I might be able to replace more code paths with
DispatchWorkItem.