Fix frequent FuncEval abort upon hitting a breakpoint in an ASP.NET Core web app #58217
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…ore web app - `AssemblySpecBindingCache` uses a cooperative-GC-mode data structure for the cache and operates on the cache from inside a lock taken in preemptive-GC-mode - So when the cache is being used, cooperative-GC-mode is entered while holding the lock, which can in turn suspend for the debugger. Then a FuncEval that also happens to operate on the cache would deadlock on acquiring the lock and would have to be aborted. - This seems to be happening very frequently when hitting an early breakpoint in a default new ASP.NET Core web app in .NET 6 when hot reload is enabled - Fixed by using the same solution that was used for the slot backpatching lock. When cooperative-GC-mode would be entered inside the lock, a different lock holder based on `CrstAndForbidSuspendForDebuggerHolder` is used, which prevents the thread from suspending for the debugger while the lock is held. The thread would instead suspend for the debugger after leaving the forbid region after releasing the lock.
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Tagging subscribers to this area: @vitek-karas, @agocke, @VSadov Issue Details
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/backport to release/6.0 |
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Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1172057212 |
hoyosjs
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Aug 26, 2021
ghost
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AssemblySpecBindingCacheuses a cooperative-GC-mode data structure for the cache and operates on the cache from inside a lock taken in preemptive-GC-modeCrstAndForbidSuspendForDebuggerHolderis used, which prevents the thread from suspending for the debugger while the lock is held. The thread would instead suspend for the debugger after leaving the forbid region after releasing the lock.