Re: [RFC PATCH 03/13] futex2: Implement vectorized wait

[Gabriel Krisman Bertazi]

André Almeida <andrealmeid@xxxxxxxxxxxxx> writes:

> Add support to wait on multiple futexes. This is the interface
> implemented by this syscall:
>
> futex_waitv(struct futex_waitv *waiters, unsigned int nr_futexes,
> 	    unsigned int flags, struct timespec *timo)
>
> struct futex_waitv {
> 	void *uaddr;
> 	unsigned int val;
> 	unsigned int flags;
> };
>
> Given an array of struct futex_waitv, wait on each uaddr. The thread
> wakes if a futex_wake() is performed at any uaddr. The syscall returns
> immediately if any waiter has *uaddr != val. *timo is an optional
> timeout value for the operation. The flags argument of the syscall
> should be used solely for specifying the timeout as realtime, if needed.
> Flags for shared futexes, sizes, etc. should be used on the individual
> flags of each waiter.

Given the previous proposal from Zebediah, one use case Wine has to
support is the ability to wait on all (instead of any) of a list of
futexes .  I suppose that could be done by a new FLAG_WAITALL passed on
the third argument of the syscall.

-- 
Gabriel Krisman Bertazi