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Comment by twoodfin | Hacker News Reader

I think it’s as simple as the industry not having reached consensus on “atomic” at the time Microsoft was naming these things. The terminology around concurrent programming was absolutely in flux in the late ‘80s & early ‘90: Windows programmers were more familiar with “critical sections” as an abstraction than mutexes.

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> Windows programmers were more familiar with “critical sections” as an abstraction than mutexes.

I disagree on that front. Mutex kernel objects have existed just as long as critical sections. Critical section objects are cheaper because they don’t switch into the kernel when not contended.

A Win32 critical section enters the kernel when blocked. (Edit: nevermind, you're not disputing this)

A pthread mutex on Linux won't enter the kernel when uncontended (thanks to futex -- this wasn't true ~20 years ago).

I would say the terms are pretty synonymous, and implementation choices differ; sometimes implementation choices are implied by the name but I don't think everybody agrees on how those choices map to names.

That’s only an implementation/optimization difference, I think it’s also relevant to understand why that’s the case. At the API level, the important distinction is that a Mutex an be shared between processes. This is great when you need it, but having the capability makes Mutexes have a somewhat expensive implementation. CriticalSections stay inside the process, so can be optimized for that (more common) use case.

Precisely.

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