threading: lock-free fast path for SemaphoreSlim.WaitAsync#125452

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thomhurst wants to merge 20 commits into

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thomhurst:semaphoreslim-cas

Commits on Jun 10, 2026

threading: lock-free fast path for SemaphoreSlim.WaitAsync
thomhurst
committed
Fix Release() race with WaitAsync CAS fast path
thomhurst
committed
Fix double-grant race in WaitAsyncCore slow path
thomhurst
committed
Fix double-grant race in WaitCore
thomhurst
committed
Remove stale Debug.Assert and add AvailableWaitHandle concurrent-init stress test
thomhurst
committed
Fix spurious SemaphoreFullException race in Release() under concurrent WaitAsync fast path
thomhurst
committed
Fix misleading comment and British spelling in WaitAsyncCore fast path
thomhurst
committed
Add concurrent fast-path and WaitCore/WaitAsync stress tests for SemaphoreSlim
thomhurst
committed
Remove SemaphoreSlimCas proxy — benchmarks now measure the real patched SemaphoreSlim
thomhurst
committed
Wrap AvailableWaitHandle stress test loop in try/finally to ensure accessor task is always cancelled
thomhurst
committed
Extract TryDecrementCount helper, add stress tests and benchmarks
thomhurst
committed
Add SpinWait backoff to AvailableWaitHandle stress test accessor loop
thomhurst
committed
Address PR feedback: fix Task<bool> typing, remove orphaned benchmark file
thomhurst
committed
Drop redundant netCount comment
thomhurst
committed
Harden lock-free fast path against memory-model and ordering hazards
thomhurst
committed
Move WaitCore retry-loop locals inside the loop
thomhurst
committed
Refactor Release_BulkRelease test to avoid two-phase deadlock
thomhurst
committed
Address Copilot review: linearizable Release check, real cancellation race test, dispose test semaphores
thomhurst
committed
Simplify async-handoff loop in Release to a single counter
thomhurst
committed
Fix Release transient count bump stealing async-waiter permits
thomhurst
committed

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threading: lock-free fast path for SemaphoreSlim.WaitAsync#125452

threading: lock-free fast path for SemaphoreSlim.WaitAsync#125452
thomhurst wants to merge 20 commits into
dotnet:mainfrom
thomhurst:semaphoreslim-cas

Commits on Jun 10, 2026

threading: lock-free fast path for SemaphoreSlim.WaitAsync

Fix Release() race with WaitAsync CAS fast path

Fix double-grant race in WaitAsyncCore slow path

Fix double-grant race in WaitCore

Remove stale Debug.Assert and add AvailableWaitHandle concurrent-init stress test

Fix spurious SemaphoreFullException race in Release() under concurrent WaitAsync fast path

Fix misleading comment and British spelling in WaitAsyncCore fast path

Add concurrent fast-path and WaitCore/WaitAsync stress tests for SemaphoreSlim

Remove SemaphoreSlimCas proxy — benchmarks now measure the real patched SemaphoreSlim

Wrap AvailableWaitHandle stress test loop in try/finally to ensure accessor task is always cancelled

Extract TryDecrementCount helper, add stress tests and benchmarks

Add SpinWait backoff to AvailableWaitHandle stress test accessor loop

Address PR feedback: fix Task<bool> typing, remove orphaned benchmark file

Drop redundant netCount comment

Harden lock-free fast path against memory-model and ordering hazards

Move WaitCore retry-loop locals inside the loop

Refactor Release_BulkRelease test to avoid two-phase deadlock

Address Copilot review: linearizable Release check, real cancellation race test, dispose test semaphores

Simplify async-handoff loop in Release to a single counter

Fix Release transient count bump stealing async-waiter permits