Align HttpListener.GetContext() exception across platforms for Stop/Abort/Close by Copilot · Pull Request #123360 · dotnet/runtime

Copilot · 2026-01-19T19:12:10Z

Description

When HttpListener.GetContext() is called after Stop(), Abort(), or Close(), Windows throws HttpListenerException with ErrorCode = 995 (SocketError.OperationAborted), but Linux throws ErrorCode = 500 (HttpStatusCode.InternalServerError). This breaks cross-platform code that handles these scenarios.

Changes

ListenerAsyncResult.Managed.cs

Changed error code from HttpStatusCode.InternalServerError to SocketError.OperationAborted when ObjectDisposedException is caught during GetContext() (line 71)
Added using System.Net.Sockets; directive

HttpListenerTests.cs

Added parameterized test using xUnit's [Theory] and [InlineData] to verify error code is 995 on all platforms for all termination scenarios (Stop, Abort, Close)
Test method: GetContext_TerminationMethodCalled_ThrowsHttpListenerExceptionWithOperationAborted
Used TaskCompletionSource for proper test synchronization to avoid race conditions in CI where termination could be called before GetContext() enters its blocking state

Code Path Analysis

On Linux, all three termination methods (Stop(), Abort(), Close()) call Cleanup() which creates a single ObjectDisposedException("listener") for pending operations
On Windows, all three methods close the request queue handle, causing the OS to return ERROR_OPERATION_ABORTED
The _inGet flag ensures the fix only affects synchronous GetContext() calls, not async BeginGetContext/EndGetContext

Example

var listener = new HttpListener();
listener.Prefixes.Add("http://localhost:8080/");
listener.Start();

var task = Task.Run(() => listener.GetContext());
listener.Stop(); // or Abort() or Close()

try 
{
    task.Wait();
}
catch (AggregateException ex) when (ex.InnerException is HttpListenerException hle)
{
    // Before: hle.ErrorCode == 500 on Linux, 995 on Windows
    // After:  hle.ErrorCode == 995 on both platforms (all scenarios)
    Assert.Equal((int)SocketError.OperationAborted, hle.ErrorCode);
}

Microsoft Reviewers

[CC @wfurt as requested]

Checklist

Code builds and tests pass locally
Added/updated tests for the changes
Follows existing code style and conventions
Documentation updated if needed

Original prompt

This section details on the original issue you should resolve

<issue_title>System.Net.HttpListener.GetContext() throws HttpListenerException with ErrorCode=HttpStatusCode.InternalServerError on Linux after Stop()</issue_title>
<issue_description>### Description

When System.Net.HttpListener.GetContext() is called after System.Net.HttpListener.Stop() on Linux, HttpListenerException with ErrorCode=HttpStatusCode.InternalServerError is thrown.

On Windows it's ErrorCode=SocketError.OperationAborted, and imo they should be aligned for all OSes.

Here is non-Windows code that throws:

runtime/src/libraries/System.Net.HttpListener/src/System/Net/Managed/ListenerAsyncResult.Managed.cs

Lines 69 to 70 in 05ed884

if (_inGet && (exc is ObjectDisposedException))

_exception = new HttpListenerException((int)HttpStatusCode.InternalServerError, SR.net_listener_close);

Reproduction Steps

.

Expected behavior

Same HttpListenerException.ExitCode on all OSes or System.InvalidOperationException, as API declares:

https://learn.microsoft.com/en-us/dotnet/api/system.net.httplistener.getcontext?view=net-10.0#exceptions

InvalidOperationException
This object has not been started or is currently stopped.

Actual behavior

When System.Net.HttpListener.GetContext() is called after System.Net.HttpListener.Stop() on Linux, HttpListenerException with ErrorCode=HttpStatusCode.InternalServerError is thrown.

On Windows it's ErrorCode=SocketError.OperationAborted.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response</issue_description>

<agent_instructions>can you look into this @copilot and also write a test.</agent_instructions>

Comments on the Issue (you are @copilot in this section)
@wfurt seems like good cleanup.

Fixes System.Net.HttpListener.GetContext() throws HttpListenerException with ErrorCode=HttpStatusCode.InternalServerError on Linux after Stop() #123344

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

…r Stop() Change the error code from HttpStatusCode.InternalServerError (500) to SocketError.OperationAborted (995) when GetContext() is called after Stop() on Linux to match Windows behavior. Add test to verify the error code is consistent across platforms. Co-authored-by: wfurt <14356188+wfurt@users.noreply.github.com>

stephentoub · 2026-01-20T02:35:46Z

/azp list

azure-pipelines · 2026-01-20T02:35:53Z

CI/CD Pipelines for this repository: runtime-coreclr outerloop runtime-coreclr jitstress runtime-coreclr jitstressregs runtime-coreclr jitstress2-jitstressregs runtime-coreclr gcstress0x3-gcstress0xc runtime-coreclr gcstress-extra runtime-coreclr r2r-extra runtime-coreclr jitstress-isas-x86 runtime-coreclr jitstress-isas-arm runtime-coreclr jitstressregs-x86 runtime-coreclr libraries-jitstressregs runtime-coreclr libraries-jitstress2-jitstressregs runtime-coreclr r2r runtime-coreclr runincontext runtime-coreclr crossgen2 runtime-libraries-coreclr outerloop runtime-libraries-coreclr outerloop-windows runtime-libraries-coreclr outerloop-linux runtime-libraries-coreclr outerloop-osx runtime runtime-libraries enterprise-linux runtime-libraries stress-http runtime-libraries stress-ssl runtime-dev-innerloop runtime-coreclr crossgen2 outerloop coreclr-release-outerloop-nightly runtime-coreclr crossgen2-composite runtime-jit-experimental runtime-coreclr libraries-jitstress dotnet-linker-tests runtime-coreclr ilasm runtime-coreclr crossgen2-composite gcstress runtime-coreclr pgo runtime-coreclr libraries-pgo Antigen runtime-community Fuzzlyn runtime-coreclr superpmi-replay runtime-wasm runtime-coreclr superpmi-diffs runtime-coreclr superpmi-asmdiffs-checked-release runtime-extra-platforms jit-cfg runtime-wasm-perf runtime-llvm runtime-cet runtime-coreclr jitstress-random runtime-coreclr libraries-jitstress-random runtime-wasm-non-libtests runtime-android runtime-androidemulator runtime-ioslike runtime-ioslikesimulator runtime-linuxbionic runtime-maccatalyst runtime-coreclr pgostress runtime-coreclr jitstress-isas-avx512 runtime-libraries-mono outerloop runtime-sanitized runtime-wasm-dbgtests runtime-wasm-optional runtime-nativeaot-outerloop runtime-coreclr superpmi-collect-test runtime-diagnostics runtime-interpreter runtime-coreclr hardware-intrinsics

stephentoub · 2026-01-20T02:36:30Z

/azp run runtime-libraries-coreclr outerloop-linux

azure-pipelines · 2026-01-20T02:36:43Z

Azure Pipelines successfully started running 1 pipeline(s).

src/libraries/System.Net.HttpListener/tests/HttpListenerTests.cs

src/libraries/System.Net.HttpListener/src/System/Net/Managed/ListenerAsyncResult.Managed.cs

stephentoub · 2026-01-20T02:40:29Z

/azp run runtime-libraries-coreclr outerloop-windows

azure-pipelines · 2026-01-20T02:40:38Z

Azure Pipelines successfully started running 1 pipeline(s).

Copilot

Pull request overview

This PR aligns the exception behavior of HttpListener.GetContext() across platforms. Previously, when called after Stop(), Windows threw HttpListenerException with ErrorCode = 995 (SocketError.OperationAborted), while Linux threw ErrorCode = 500 (HttpStatusCode.InternalServerError). The fix ensures both platforms consistently use SocketError.OperationAborted.

Changes:

Updated Linux implementation to throw HttpListenerException with SocketError.OperationAborted error code (995) instead of HttpStatusCode.InternalServerError (500)
Added test to verify cross-platform consistency of error code

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
ListenerAsyncResult.Managed.cs	Changed error code from `HttpStatusCode.InternalServerError` to `SocketError.OperationAborted` when `ObjectDisposedException` is caught; added required using directive
HttpListenerTests.cs	Added test to verify `GetContext()` throws `HttpListenerException` with error code 995 when called after `Stop()`

Use TaskCompletionSource to ensure GetContext() is called before Stop() to avoid race condition where Stop() could be called first, causing InvalidOperationException instead of HttpListenerException. Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Add comprehensive tests to verify that GetContext() throws HttpListenerException with SocketError.OperationAborted for all termination scenarios: Stop(), Abort(), and Close(). All three methods call Cleanup() which creates ObjectDisposedException for pending async operations, which is now consistently converted to OperationAborted. Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

dotnet-policy-service · 2026-01-26T04:55:55Z

Tagging subscribers to this area: @karelz, @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

rzikm

LGTM

src/libraries/System.Net.HttpListener/tests/HttpListenerTests.cs

Consolidated three nearly identical tests into a single parameterized test using xUnit's [Theory] and [InlineData] attributes to test Stop(), Abort(), and Close() scenarios with the same logic. Co-authored-by: wfurt <14356188+wfurt@users.noreply.github.com>

wfurt

LGTM

Initial plan

b5506af

Copilot AI assigned Copilot and wfurt Jan 19, 2026

Copilot started work on behalf of wfurt January 19, 2026 19:12 View session

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Copilot AI changed the title ~~[WIP] Fix HttpListener exception handling on Linux~~ Align HttpListener.GetContext() exception across platforms when called after Stop() Jan 19, 2026

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Copilot finished work on behalf of wfurt January 19, 2026 20:04

stephentoub marked this pull request as ready for review January 20, 2026 02:36

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Copilot AI changed the title ~~Align HttpListener.GetContext() exception across platforms when called after Stop()~~ Align HttpListener.GetContext() exception across platforms for Stop/Abort/Close Jan 20, 2026

Copilot finished work on behalf of stephentoub January 20, 2026 02:58

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Merge branch 'main' into copilot/fix-http-listener-exception

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This was referenced Feb 3, 2026

iOS.Device test WorkItemExecutions #122874

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XHarness package install failure on iOS due to devicectl NSPOSIXErrorDomain error 49 #123796

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build-analysis bot mentioned this pull request Feb 4, 2026

[wasm] OpenQA.Selenium.WebDriverTimeoutException: timeout: Timed out receiving message from renderer #117486

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wfurt added 2 commits February 10, 2026 15:09

Merge branch 'main' into copilot/fix-http-listener-exception

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Merge branch 'main' into copilot/fix-http-listener-exception

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wfurt enabled auto-merge (squash) March 3, 2026 13:56

build-analysis bot mentioned this pull request Mar 3, 2026

[android][clr] No peer certificates when executing System.Net.Http.Functional.Tests on Android emulator #124526

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Merge branch 'main' into copilot/fix-http-listener-exception

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wfurt merged commit e4c1aa0 into main Mar 4, 2026
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build-analysis bot mentioned this pull request Mar 4, 2026

iOS tests failing with WORKLOAD TIMED OUT - Killing user command. #108103

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[main] Source code updates from dotnet/runtime dotnet/dotnet#5245

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Align HttpListener.GetContext() exception across platforms for Stop/Abort/Close#123360

Align HttpListener.GetContext() exception across platforms for Stop/Abort/Close#123360
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	if (_inGet && (exc is ObjectDisposedException))
	_exception = new HttpListenerException((int)HttpStatusCode.InternalServerError, SR.net_listener_close);

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Description

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Expected behavior

Actual behavior

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