Re:Towards userspaceification of POSIX – part I: signal hand...
by Animats on Saturday August 03, 2024 @01:51AM
(#41144914)
Why emulate POSIX signal semantics? Those are a holdover from the single-thread UNIX era. Events should be delivered by threads or async calls. Signals should be reserved for exceptions, things you don't return to, like segfaults.
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Re:Towards userspaceification of POSIX – part I: signal hand...
by 4lDO2 on Saturday August 03, 2024 @06:00AM
(#41145658)
The rationale was discussed in-depth earlier on LWN (https://lwn.net/Articles/982186/).
Signals are useful as a software analogue to hardware interrupts, even though they are probably too low-level for most application use cases. They are for example used by the Golang runtime to preempt threads AFAIU, which wouldn't otherwise be possible non-cooperatively. Intel even included an ISA extension called user-IPIs, which is similar to signals.