[Timongcraft]

Overview

Fix corruption when using ClipboardPattern and disabling on disk clipboards as some implementations have an unsafe cache.

This does not fix RandomFullClipboardPattern, which also seems affected but I'm not sure how to wrap the clipboard properly as it uses the old single get clipboard (seemingly on purpose) but idk if or how that should be wrapped as we'd need a map or list, no?

Description

Add a temporary wrapper to sync block access in clipboards for ClipboardPattern.

Submitter Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
  - [ ] New public fields and methods are annotated with @since TODO.
• I read and followed the contribution guidelines.

[Timongcraft]

Caused by: org.gradle.internal.resolve.ArtifactNotFoundException: Could not find yarn-1.21.1+build.3-mergedv2.jar (net.fabricmc:yarn:1.21.1+build.3).

hm...

[Copilot]

🟡 Changes recommended

World-backed clipboards bypass synchronization even when their arbitrary backing extent is not concurrency-safe.

1 open finding

• Avoid claiming parallel-read safety for arbitrary backing extents · New

What changed in this PR

Adds synchronized clipboard reads to prevent corruption during parallel ClipboardPattern filtering.

Changes:

• Introduces a synchronized read wrapper.
• Adds parallel-access capability detection.
• Exempts selected clipboard implementations from wrapping.

File	Description
ClipboardPattern.java	Wraps clipboard reads for concurrency safety.
Clipboard.java	Adds the parallel-access capability API.
BlockArrayClipboard.java	Delegates capability to its parent.
WorldCopyClipboard.java	Declares parallel-read support.
EmptyClipboard.java	Declares parallel-read support.
DiskOptimizedClipboard.java	Declares parallel-read support.
ConcurrentReadClipboard.java	Implements synchronized block reads.

🧠 Review effort: Balanced

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[dordsor21]

Suggested change

	@ApiStatus.Experimental // Temporary wrapper
	public class ConcurrentReadClipboard implements Clipboard {
	public class ConcurrentReadOnlyClipboard implements Clipboard {

I think there's no need for the experimental label here - it's likely to need to stay. Also worth stating readonly explicitly

[Timongcraft]

Should Clipboard#supportsParallelAccess also not be marked experimental?

[PierreSchwang]

Would it make sense to use a marker interface like public interface ParallelAccessClipboard extends Clipboard and a SynchronizedAccessClipboard as the implementation for wrapping non-parallel access clipboards?

That would allow a more or less clean method directly on the Clipboard like forParallelAccess() or something (not that it depends on the implementation details). Not sure if that's really required as of now tbf.

I don't really like the name personally - "parallel access" kind of implies parallel / multi-threaded writing access as well - but I don't have any better one right now. All just nitpicks.

[Timongcraft]

If that is desired that could also be done, sure.
Is your intention to give third party implementions more abilities for wrapping?