[NativeAOT] EventPipe current_thread_get_id performance

[jkotas]

          Mono implementation of this method just returns `pthread_self` that is the opaque thread ID and that is very cheap to get (it just returns thread local static):

runtime/src/mono/mono/eventpipe/ep-rt-mono.h

Line 962 in 2b122d3

return mono_native_thread_id_get ();

runtime/src/mono/mono/utils/mono-threads-posix.c

Line 242 in 2b122d3

return pthread_self ();

Similarly, the CoreCLR implementation built on top of Win32 PAL emulator is fairly cheap.

PalGetCurrentThreadIdForLogging is implemented as a raw syscall(SYS_gettid) that will be at least 100x more expensive than pthread_self.

This smells like a pretty significant performance issue.

Originally posted by @jkotas in #86226 (comment)

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Issue Details

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          Mono implementation of this method just returns `pthread_self` that is the opaque thread ID and that is very cheap to get (it just returns thread local static):

runtime/src/mono/mono/eventpipe/ep-rt-mono.h

Line 962 in 2b122d3

return mono_native_thread_id_get ();

runtime/src/mono/mono/utils/mono-threads-posix.c

Line 242 in 2b122d3

return pthread_self ();

Similarly, the CoreCLR implementation built on top of Win32 PAL emulator is fairly cheap.

PalGetCurrentThreadIdForLogging is implemented as a raw syscall(SYS_gettid) that will be at least 100x more expensive than pthread_self.

This smells like a pretty significant performance issue.

Originally posted by @jkotas in #86226 (comment)

Author:	jkotas
Assignees:	-
Labels:	untriaged, area-NativeAOT-coreclr, needs-area-label
Milestone:	-