[EventPipe] Add dotnet_ipc_created mapping

[mdh1418]

External tools interested in connecting to the runtime's diagnostic ports benefit from a low-overhead IO signal that a .NET process is ready to receive IPC commands, instead of trying to IO over all known temp file directories looking for diagnostic ports for each process.

Following the discussion in microsoft/one-collect#226, this PR adds a new mapping, dotnet_ipc_created, that is created once a .NET process' singular listen port is successfully created.

Testing

userevents runtime tests now work on NativeAOT with the record-trace change microsoft/one-collect#229

mihw@CPC-mihw-6KMZDM:~/repo/runtime$ ./artifacts/tests/coreclr/linux.x64.Release/tracing/userevents/basic/basic/basic.sh
BEGIN EXECUTION
/home/mihw/repo/runtime/src/tests/Common/scripts/nativeaottest.sh /home/mihw/repo/runtime/artifacts/tests/coreclr/linux.x64.Release/tracing/userevents/basic/basic/ basic.dll ''
traceeAssemblyPath:
Starting record-trace: sudo -n /home/mihw/repo/runtime/artifacts/tests/coreclr/linux.x64.Release/tracing/userevents/common/userevents_common/record-trace --script-file /home/mihw/repo/runtime/artifacts/tests/coreclr/linux.x64.Release/tracing/userevents/basic/basic/native/../basic.script --out /tmp/tmpBoli5K.nettrace --log-mode console --log-filter error,one_collect::helpers::dotnet::os::linux=debug
record-trace started with PID: 1543079
[record-trace] 2026-01-29T22:55:19.967428Z DEBUG one_collect::helpers::dotnet::os::linux: Registered .NET tracepoint: name=OC_DotNet_Microsoft_Windows_DotNETRuntime_1543081_All, callstacks=false, use_names=true
Starting tracee process: /home/mihw/repo/runtime/artifacts/tests/coreclr/linux.x64.Release/tracing/userevents/basic/basic/native/basic tracee
Tracee process started with PID: 1543083
Waiting for tracee process to exit...
[record-trace] 2026-01-29T22:55:20.093460Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543063, nspid=1543063
[record-trace] 2026-01-29T22:55:20.093476Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543063, nspid=1543063
[record-trace] 2026-01-29T22:55:20.094446Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543063, nspid=1543063
[record-trace] Recording started.  Press CTRL+C to stop.
[record-trace] 2026-01-29T22:55:20.097795Z  INFO one_collect::helpers::dotnet::os::linux: Enabled .NET events for process: pid=1543063
[record-trace] 2026-01-29T22:55:20.098955Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543083, nspid=1543083
[record-trace] 2026-01-29T22:55:20.099085Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543083, nspid=1543083
[record-trace] 2026-01-29T22:55:20.100017Z DEBUG one_collect::helpers::dotnet::os::linux: Opened diagnostic socket: pid=1543083, nspid=1543083
[record-trace] 2026-01-29T22:55:20.104842Z  INFO one_collect::helpers::dotnet::os::linux: Enabled .NET events for process: pid=1543083
Stopping record-trace with SIGINT.
Waiting for record-trace to exit...
[record-trace] Recording stopped.
[record-trace] Resolving symbols.
[record-trace] Finished recording trace.
[record-trace] Trace written to /tmp/tmpBoli5K.nettrace
Expected: 100
Actual: 100
END EXECUTION - PASSED

[Copilot]

Pull request overview

This PR adds a dotnet_ipc_created memory mapping to signal when a .NET process's diagnostic port is ready to receive IPC commands. This provides external tracing tools with a low-overhead mechanism to detect when the runtime is ready, instead of having to poll temporary file directories. The implementation uses Linux's memfd_create syscall to create a named memory mapping that can be detected by tools like one-collect.

Changes:

• Added CMake configuration checks for sys/mman.h header and memfd_create syscall availability
• Created a memory mapping named "dotnet_ipc_created" when the default diagnostic listen port is successfully initialized
• The mapping serves as a signal mechanism for external tools to detect IPC readiness

Reviewed changes

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

File	Description
src/native/eventpipe/configure.cmake	Added CMake checks for sys/syscall.h, sys/mman.h, and __NR_memfd_create symbol
src/native/eventpipe/ep-shared-config.h.in	Added CMake define declarations for HAVE_SYS_MMAN_H and HAVE_MEMFD_CREATE
src/native/eventpipe/ds-ipc.c	Implemented the dotnet_ipc_created mapping creation using memfd_create and mmap when the default listen port is successfully created

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

[noahfalk]

👍

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

[mdh1418]

/backport to release/10.0

[github-actions]

Started backporting to release/10.0 (link to workflow run)