[Merged by Bors] - Remove ExclusiveSystemParam::apply
#7489
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
JoJoJet
added
A-ECS
|
I'm in favor of removing this footgun. |
alice-i-cecile
approved these changes
Feb 3, 2023
|
bors r+ |
bors bot
pushed a commit
that referenced
this pull request
Feb 4, 2023
# Objective The trait method `SystemParam::apply` allows a `SystemParam` type to defer world mutations, which is internally used to apply `Commands` at the end of the stage. Any operations that require `&mut World` access must be deferred in this way, since parallel systems do not have exclusive access to the world. The `ExclusiveSystemParam` trait (added in #6083) has an `apply` method which serves the same purpose. However, deferring mutations in this way does not make sense for exclusive systems since they already have `&mut World` access: there is no need to wait until a hard sync point, as the system *is* a hard sync point. World mutations can and should be performed within the body of the system. ## Solution Remove the method. There were no implementations of this method in the engine. --- ## Changelog *Note for maintainers: this changelog makes more sense if it's placed above the one for #6919.* - Removed the method `ExclusiveSystemParamState::apply`. ## Migration Guide *Note for maintainers: this migration guide makes more sense if it's placed above the one for #6919.* The trait method `ExclusiveSystemParamState::apply` has been removed. If you have an exclusive system with buffers that must be applied, you should apply them within the body of the exclusive system.
|
Pull request successfully merged into main. Build succeeded:
|
bors
bot
changed the title
ExclusiveSystemParam::applyExclusiveSystemParam::apply
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.
Objective
The trait method
SystemParam::applyallows aSystemParamtype to defer world mutations, which is internally used to applyCommandsat the end of the stage. Any operations that require&mut Worldaccess must be deferred in this way, since parallel systems do not have exclusive access to the world.The
ExclusiveSystemParamtrait (added in #6083) has anapplymethod which serves the same purpose. However, deferring mutations in this way does not make sense for exclusive systems since they already have&mut Worldaccess: there is no need to wait until a hard sync point, as the system is a hard sync point. World mutations can and should be performed within the body of the system.Solution
Remove the method. There were no implementations of this method in the engine.
Changelog
Note for maintainers: this changelog makes more sense if it's placed above the one for #6919.
ExclusiveSystemParamState::apply.Migration Guide
Note for maintainers: this migration guide makes more sense if it's placed above the one for #6919.
The trait method
ExclusiveSystemParamState::applyhas been removed. If you have an exclusive system with buffers that must be applied, you should apply them within the body of the exclusive system.