SunOS process and thread support

[gwr]

Read binary psinfo for System.Diagnostic.Process on SunOS (Solaris or illumos).
No failures in System.Diagnostic.Process.Tests (but lots of skip)

BTW, I tried rebasing on main from Mon. this week and ran into problems downloading stuff.
Not sure why, but it didn't seem to have anything to do with my changes.

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[am11]

Lets drop the changes which are already submitted in other PRs.

[am11]

Good start! I've left initial feedback, which I anticipate the maintainers will point out. :)

[gwr]

Good start! I've left initial feedback, which I anticipate the maintainers will point out. :)

Thanks. I had not yet seen #105207 when I opened this. I think @AustinWise and I should figure out how to get the prerequisite fixes shown there (and here) all integrated, and then I'll rebase the last parts of this onto that.

[gwr]

Lets drop the changes which are already submitted in other PRs.

I'd love to, but I do not see a way to do "stacked" PRs, where one PR targets the branch of another PR.
If I drop the prerequisite changes then things break. Suggestions welcome.

[am11]

Create a local branch feature/illumos-port with all the miscellaneous changes. Then keep this branch only for System.Diagnostics.Port changes. You can git cherry-pick <spaces-separated commit hashes> across the branches.

[AustinWise]

The C# for reading from procfs and enumerating threads/processes looks good to me.

[gwr]

Rebased and squashed

[am11]

Looks good to me. Thanks for this @gwr! This is one major step to complete the shared framework on illumos-x64 and enabling msbuild/sdk. 👍

@adamsitnik, @jkotas, PTAL.

[am11]

@gwr fyi, we are not required to rebase for every commit merging in main branch. It's rather a busy repo so GH will likely always show you that your branch is behind by X number of commits. The maintainers can do the rebase if deemed necessary.

[gwr]

Updated to fix a comment (nit)

[gwr]

@gwr fyi, we are not required to rebase for every commit merging in main branch. It's rather a busy repo so GH will likely always show you that your branch is behind by X number of commits. The maintainers can do the rebase if deemed necessary.

OK, thanks. Won't do it too often.

[gwr]

Here too; Can anyone tell me what to do about the runtime checks that reported failure?

[jkotas]

Can anyone tell me what to do about the runtime checks that reported failure?

Don't worry about them. They are not related to your change.

[gwr]

nudge 2

[gwr]

nudge 3

[adamsitnik]

Please excuse me for lack of response, I am busy fixing some last minute bugs for .NET 9. I should be less busy after the RC2 branch snap next week and I hope to be able to review it then.

[jeffhandley]

Sorry for the delay on this, @gwr. I just merged main into your branch to get a fresh build.

[Copilot]

Pull Request Overview

This PR introduces SunOS (Solaris and illumos) support for System.Diagnostics.Process by implementing new SunOS-specific interop routines and process/thread management code. Key changes include:

• New files for reading process and thread information from procfs on SunOS.
• Updates to process and thread APIs to support SunOS properties and priority mapping.
• Adjustments in test utilities and environment code to incorporate SunOS detection and behavior.

Reviewed Changes

Copilot reviewed 12 out of 17 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessThread.SunOS.cs	Implements SunOS thread info retrieval and property mapping.
src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.TryGetProcessInfoById.cs	Adds support for reading process info from procfs on SunOS.
src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.TryGetThreadInfoById.cs	Provides SunOS-specific thread info retrieval from procfs.
src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.SunOS.cs	Implements SunOS properties for Process, including start time and CPU time calculation.
src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFs.Definitions.cs	Defines SunOS procfs structures and constants.
src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessManager.SunOS.cs	Integrates process management and enumeration for SunOS.
src/libraries/Common/src/Interop/Unix/System.Native/Interop.TimeSpec.cs	Introduces a TimeSpec struct for time conversions.
src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs	Updates platform detection to include SunOS.
src/libraries/System.Diagnostics.Process/tests/ProcessTests.cs	Adjusts tests to handle working set issues on SunOS.
src/libraries/System.Private.CoreLib/src/System/Environment.SunOS.cs	Updates environment working set retrieval for SunOS.
src/libraries/Common/src/Interop/Unix/System.Native/Interop.UTimensat.cs	Removes duplicate TimeSpec definition.
src/libraries/Common/src/Interop/SunOS/procfs/Interop.ProcFsStat.TryReadProcessStatusInfo.cs	Removes legacy status info retrieval code.

Files not reviewed (5)

• src/libraries/System.Diagnostics.Process/src/System.Diagnostics.Process.csproj: Language not supported
• src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems: Language not supported
• src/native/libs/System.Native/entrypoints.c: Language not supported
• src/native/libs/System.Native/pal_io.c: Language not supported
• src/native/libs/System.Native/pal_io.h: Language not supported

Comments suppressed due to low confidence (1)

src/libraries/Common/tests/TestUtilities/System/PlatformDetection.cs:48

• [nitpick] Consider renaming 'Isillumos' to 'IsIllumos' for improved readability and consistency with .NET naming conventions.

public static bool Isillumos => RuntimeInformation.IsOSPlatform(OSPlatform.Create("ILLUMOS"));

[Copilot]

Ensure that ArrayBuilder is properly instantiated instead of using the default value to prevent potential NullReferenceExceptions when adding items.

Suggested change

	ArrayBuilder<ProcessInfo> processes = default;
	ArrayBuilder<ProcessInfo> processes = new ArrayBuilder<ProcessInfo>();