[PATCH v2 4/4] c2y: Add function cnd_timedwait_base and mtx_timedlock_base

[罗勇刚(Yonggang Luo)]

On Wed, Jun 21, 2023 at 10:31 PM enh <enh@google.com> wrote:
>
>
>
> On Wed, Jun 21, 2023 at 2:21 AM 罗勇刚(Yonggang Luo) <luoyonggang@gmail.com>
wrote:
>>
>>
>>
>> On Wed, Jun 21, 2023 at 4:41 AM Joseph Myers <joseph@codesourcery.com>
wrote:
>> >
>> > On Wed, 21 Jun 2023, Yonggang Luo via Libc-alpha wrote:
>> >
>> > > diff --git a/sysdeps/pthread/threads.h b/sysdeps/pthread/threads.h
>> > > index d88d7a3ddd..4f61ad9236 100644
>> > > --- a/sysdeps/pthread/threads.h
>> > > +++ b/sysdeps/pthread/threads.h
>> > > @@ -146,14 +146,22 @@ extern int mtx_lock (mtx_t *__mutex);
>> > >  #ifndef __USE_TIME_BITS64
>> > >  extern int mtx_timedlock (mtx_t *__restrict __mutex,
>> > >                         const struct timespec *__restrict
__time_point);
>> > > +extern int mtx_timedlock_base (mtx_t *__restrict __mutex, int
time_base,
>> > > +                               const struct timespec *__restrict
__time_point);
>> >
>> > As noted, this should be conditional on __USE_GNU.  Since you didn't
make
>> > it conditional, I'd expect it to have failed the conform/ namespace
tests
>> > - both for the mtx_timedlock_base name itself if there weren't
incorrect
>> > conform/ changes in the patch series, and for the time_base parameter
>> > (parameters in installed headers should always have a leading __).  How
>> > did you test these patches?
>>
>> I am not testing these patches yet(as a new contributor for glibc, don't
know how to do that yet),
>> and for this patch, I'd like to know if the prototype of these two
functions is proper first
>>
>> int mtx_timedlock_base(mtx_t *restrict m, int time_base, const struct
timespec *restrict ts);
>>
>> int cnd_timedwait_base(cnd_t *restrict c, mtx_t *restrict m, int
time_base, const struct timespec *restrict ts);
>>
>> The function name was suggested by Jens Gustedt, and indeed I also
thought about this name in the first place(because posix has cond_clockwait
and mutex_clocklock already). And seems enh also like this
>
>
> well, to the extent that i think "pthreads that's also available on
Windows" is useful to some, sure, i'll continue to add the trivial inline
functions to bionic so that this is actually portable (
https://android.googlesource.com/platform/bionic/+/master/libc/include/bits/threads_inlines.h).
but for Android host tools themselves, i think we'll continue to use
std::thread or pthreads via mingw.
>
> but my real feedback earlier was the same as what you're seeing here:
"since this is a WG14-driven thing, it should come as a proposal from there
first". anyone using bionic or glibc already has perfectly good pthread
apis, so no real need for this stuff until/unless it's in Windows. (and
last time i looked, Windows hadn't actually implemented the existing
<threads.h> stuff yet?)

Yeah, you are correct, windows msvc doesn't have either pthread or c11
threads, and pthreads is so huge, so there is multiple third-party c11
threads implementation for MSVC, that's why I wanna c2y threads comes with
monotonic mtx_timedlock cnd_timedwait support, so that the third-party c11
threads implementation have a consistence API to implement.

So my question, anyone in this threads have suggestion about the newly
proposed API:

 int mtx_timedlock_base (mtx_t*, int, const struct timespec*);
 int cnd_timedwait_base (cnd_t*, mtx_t*, int, const struct timespec*);

>
>>
>> If we have minimal agreement about this proposal, I'd like to add tests
for it. But still, I don't think
>> __USE_GNU is a good name for it, because it's for C2y or C3x, any better
option for this, so that it's not GNU restricted, for example, suppose MSVC
also wants to implement this?
>>
>>
>> >
>> > > +extern int __REDIRECT (mtx_timedlock_base, (mtx_t *__restrict
__mutex,
>> > > +                                            int time_base,
>> > > +                                            const struct timespec
*__restrict
>> > > +                                            __time_point),
>> > > +                       __mtx_timedlock_base64);
>> >
>> > Likewise, should be conditional on __USE_GNU and time_base should be
>> > __time_base.
>> >
>> > > +extern int cnd_timedwait_base (cnd_t *__restrict __cond,
>> > > +                               mtx_t *__restrict __mutex, int
time_base,
>> > > +                               const struct timespec *__restrict
__time_point);
>> >
>> > > +extern int __REDIRECT (cnd_timedwait_base, (cnd_t *__restrict
__cond,
>> > > +                                            mtx_t *__restrict
__mutex,
>> > > +                                            int time_base,
>> > > +                                            const struct timespec
*__restrict
>> > > +                                            __time_point),
>> >
>> > Likewise.
>> >
>> > --
>> > Joseph S. Myers
>> > joseph@codesourcery.com
>>
>>
>>
>> --
>>          此致
>> 礼
>> 罗勇刚
>> Yours
>>     sincerely,
>> Yonggang Luo



--
         此致
礼
罗勇刚
Yours
    sincerely,
Yonggang Luo