Add reset! function and safe rewind! behavior

[mgyoo86]

Summary

• Add reset!(pool) for state-only reset (preserves allocated vectors)
• Make rewind!(pool) safe when called without matching checkpoint!
• Clean up internal API and reorganize state.jl

New

• reset!(pool): State-only reset (n_active=0, stacks to sentinel, vectors preserved)
• reset!(pool, Type): Type-specific reset
• reset!(pool, Type...): Multi-type reset

Modified

• rewind!(pool): At depth=1 (no checkpoint), delegates to reset! instead of error/undefined behavior
• rewind!(pool, Type): At depth=1, delegates to reset!(TypedPool)
• rewind!(pool, Type...): At depth=1, delegates to reset! for each typed pool

API Comparison

Function	n_active	Checkpoint stacks	Vectors
rewind!	Restore to checkpoint	Pop	Preserved
reset!	Set to 0	Clear to sentinel	Preserved
empty!	Set to 0	Clear to sentinel	Cleared

Use Case: Unmanaged acquire cleanup

function inner!(pool)
    v = acquire!(pool, Float64, 100)
    # No rewind! called
end

for _ in 1:1000
    inner!(pool)  # n_active grows
end

# Option 1: Use reset! (new API)
reset!(pool)  # Clear n_active, keep vectors for reuse

# Option 2: Use rewind! (now safe at global scope)
rewind!(pool)  # Safe! Delegates to reset! when no checkpoint exists

Safety Improvements

• All rewind! variants at depth=1 (no checkpoint) now delegate to reset!
  • rewind!(pool), rewind!(pool, Type), rewind!(pool, Type...)
• Multiple rewind! calls without checkpoint are safe
• reset! followed by rewind! is safe
• Normal checkpoint!/rewind! cycle works after reset!
• All rewind operations use orphan-safe _rewind_typed_pool! with depth tracking

Internal Cleanup

• Remove redundant TypedPool public overloads (checkpoint!(tp), rewind!(tp))
• Consolidate internal helpers: _checkpoint_typed_pool!, _rewind_typed_pool!
• Reorganize state.jl into clear sections: checkpoint!, rewind!, empty!, reset!

Changes

• src/state.jl: Add reset!, add depth=1 guard to rewind!, reorganize structure
• test/test_state.jl: Add 20+ tests for reset! and safe rewind behavior

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.68%. Comparing base (1e6cd56) to head (4305ac3).
⚠️ Report is 10 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master       #8      +/-   ##
==========================================
+ Coverage   96.52%   96.68%   +0.16%     
==========================================
  Files           7        7              
  Lines         575      603      +28     
==========================================
+ Hits          555      583      +28     
  Misses         20       20              

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[Copilot]

Pull request overview

This PR adds a new reset! function for state-only cleanup that preserves allocated storage, and improves safety of rewind! when called without a matching checkpoint. The changes enable cleanup of unmanaged acquires while avoiding memory reallocation costs.

Key Changes:

• New reset! function that clears state (n_active, checkpoint stacks) while preserving all allocated storage (vectors, views, caches)
• Safety guard in rewind!(pool::AdaptiveArrayPool) that delegates to reset! when called at depth=1 (no checkpoint)
• Comprehensive test coverage with 14 new tests for reset! and 4 tests for safe rewind! behavior

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
src/AdaptiveArrayPools.jl	Exports the new reset! function
src/state.jl	Implements reset! for TypedPool and AdaptiveArrayPool; adds depth=1 safety guard to rewind!
test/test_state.jl	Adds comprehensive tests for reset! behavior and safe rewind! at depth=1

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

---

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