Suppress ExecutionContext flow in BeginErrorReadLine#1498
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ericstj wants to merge 1 commit intomodelcontextprotocol:mainfrom
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Suppress ExecutionContext flow in BeginErrorReadLine#1498ericstj wants to merge 1 commit intomodelcontextprotocol:mainfrom
ericstj wants to merge 1 commit intomodelcontextprotocol:mainfrom
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Process.BeginErrorReadLine() captures the caller's ExecutionContext, causing AsyncLocal values to leak to the background stderr reader thread. This is undesirable—the stderr handler is a long-lived background I/O callback that shouldn't inherit ambient state from whichever call site happened to create the transport. Wrap BeginErrorReadLine() in ExecutionContext.SuppressFlow() so the stderr reader gets a clean context. Add a test that sets an AsyncLocal before creating the transport and verifies the stderr callback does NOT see the value. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
stephentoub
approved these changes
Apr 3, 2026
Contributor
|
This is reasonable hygiene, but I'm curious if this is solving some problem you found in the tests? |
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Process.BeginErrorReadLine() captures the caller's ExecutionContext, causing AsyncLocal values to leak to the background stderr reader thread. This is undesirable—the stderr handler is a long-lived background I/O callback that shouldn't inherit ambient state from whichever call site happened to create the transport.
Wrap BeginErrorReadLine() in ExecutionContext.SuppressFlow() so the stderr reader gets a clean context.
Add a test that sets an AsyncLocal before creating the transport and verifies the stderr callback does NOT see the value.