Re: [RFC PATCH v2 00/13] Add futex2 syscall

[Stefan Metzmacher]

Am 08.03.21 um 12:11 schrieb David Laight:
> From: Stefan Metzmacher
>> Sent: 07 March 2021 11:35
>>
>> Hi André,
>>>  ** The wait on multiple problem
>>>
>>>  The use case lies in the Wine implementation of the Windows NT interface
>>>  WaitMultipleObjects. This Windows API function allows a thread to sleep
>>>  waiting on the first of a set of event sources (mutexes, timers, signal,
>>>  console input, etc) to signal.
> 
> They are all events.
> You can only wait on either events or sockets (using select).
> There is a socket api to signal an event when data arrives (etc).
> There is also the insane (these days) restriction of 64 events.

Ok.

>> With that in mind would it be good to have some interaction with epoll (and similar calls)?
> 
> Or hook something up so that pollwakeup can kick a futex as well
> as waking up poll() and adding an event to epoll().

I guess as FUTEX_FD was already there and was removed we can stop this discussion.

If there will every be the need to an async call, I guess a io_uring based one would
be the best...

metze