Track removing workaround to not use pthread robust mutexes for named mutexes on arm32/arm64 Linux

[kouvel]

• Issue was in glibc as described here: [ARM/Linux] paltest_namedmutex_test1 hangs #6014 (comment)
• Issue was fixed in glibc 2.24 according to https://sourceware.org/bugzilla/show_bug.cgi?id=20263#c9
• Workaround in named mutex implementation:

  runtime/src/coreclr/pal/src/include/pal/mutex.hpp

  Lines 123 to 124 in fdcedd8

  	// - Temporarily disabling usage of pthread process-shared mutexes on ARM/ARM64 due to functional issues that cannot easily be
  	// detected with code due to hangs. See https://github.com/dotnet/runtime/issues/6014.

• There still appear to be some supported Linux distro versions that use a glibc version less than 2.24. This issue is to track removing the workaround above once all supported distros start using glibc 2.24 or greater. Also need to ensure that the use cases in [ARM/Linux] paltest_namedmutex_test1 hangs #6014 are not affected.

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Issue Details

---

• Issue was in glibc as described here: [ARM/Linux] paltest_namedmutex_test1 hangs #6014 (comment)
• Issue was fixed in glibc 2.24 according to https://sourceware.org/bugzilla/show_bug.cgi?id=20263#c9
• Workaround in named mutex implementation:

  runtime/src/coreclr/pal/src/include/pal/mutex.hpp

  Lines 123 to 124 in fdcedd8

  	// - Temporarily disabling usage of pthread process-shared mutexes on ARM/ARM64 due to functional issues that cannot easily be
  	// detected with code due to hangs. See https://github.com/dotnet/runtime/issues/6014.

• There still appear to be some supported Linux distro versions that use a glibc version less than 2.24. This issue is to track removing the workaround above once all supported distros start using glibc 2.24 or greater. Also need to ensure that the use cases in [ARM/Linux] paltest_namedmutex_test1 hangs #6014 are not affected.

Author:	kouvel
Assignees:	-
Labels:	area-System.Threading
Milestone:	8.0.0

[janvorli]

@kouvel Starting with #68561, we are now building our arm and arm64 binaries on Ubuntu 18.04, so the minimum supported glibc is 2.27.

[kouvel]

I see, thanks @janvorli. I figure that means that CentOS 7 will also require glibc >= 2.27 for .NET 7, is that correct? If so, I think we can go ahead and undo the workaround.

[kouvel]

Duplicate of #65929