This gives us C11 Annex K's qsort_s(), which -- despite being Annex K --
is potentially useful in that it resolves the long-standing argument
about what the signature of qsort_r() is supposed to be. I'll import
it here first, and worry about actually using it separately (given that
glibc/musl and macOS/iOS don't have it; only Windows and [now] FreeBSD,
but not even the other BSDs).
For now, though, this change is a no-op.
Bug: http://b/17203231
Bug: http://b/31807750
Test: treehugger
Change-Id: Id8d2916b608ba8251df8643694da542e9b11eaae
* Rationale
The question often comes up of how to use multiple time zones in C code.
If you're single-threaded, you can just use setenv() to manipulate $TZ.
toybox does this, for example. But that's not thread-safe in two
distinct ways: firstly, getenv() is not thread-safe with respect to
modifications to the environment (and between the way putenv() is
specified and the existence of environ, it's not obvious how to fully
fix that), and secondly the _caller_ needs to ensure that no other
threads are using tzset() or any function that behaves "as if" tzset()
was called (which is neither easy to determine nor easy to ensure).
This isn't a bigger problem because most of the time the right answer
is to stop pretending that libc is at all suitable for any i18n, and
switch to icu4c instead. (The NDK icu4c headers do not include ucal_*,
so this is not a realistic option for most applications.)
But what if you're somewhere in between? Like the rust chrono library,
for example? What then?
Currently their "least worst" option is to reinvent the entire wheel and
read our tzdata files. Which isn't a great solution for anyone, for
obvious maintainability reasons.
So it's probably time we broke the catch-22 here and joined NetBSD in
offering a less broken API than standard C has for the last 40 years.
Sure, any would-be caller will have to have a separate "is this
Android?" and even "is this API level >= 35?" path, but that will fix
itself sometime in the 2030s when developers can just assume "yes, it
is", whereas if we keep putting off exposing anything, this problem
never gets solved.
(No-one's bothered to try to implement the std::chrono::time_zone
functionality in libc++ yet, but they'll face a similar problem if/when
they do.)
* Implementation
The good news is that tzcode already implements these functions, so
there's relatively little here.
I've chosen not to expose `struct state` because `struct __timezone_t`
makes for clearer error messages, given that compiler diagnostics will
show the underlying type name (`struct __timezone_t*`) rather than the
typedef name (`timezone_t`) that's used in calling code.
I've moved us over to FreeBSD's wcsftime() rather than keep the OpenBSD
one building --- I've long wanted to only have one implementation here,
and FreeBSD is already doing the "convert back and forth, calling the
non-wide function in the middle" dance that I'd hoped to get round to
doing myself someday. This should mean that our strftime() and
wcsftime() behaviors can't easily diverge in future, plus macOS/iOS are
mostly FreeBSD, so any bugs will likely be interoperable with the other
major mobile operating system, so there's something nice for everyone
there!
The FreeBSD wcsftime() implementation includes a wcsftime_l()
implementation, so that's one stub we can remove. The flip side of that
is that it uses mbsrtowcs_l() and wcsrtombs_l() which we didn't
previously have. So expose those as aliases of mbsrtowcs() and
wcsrtombs().
Bug: https://github.com/chronotope/chrono/issues/499
Test: treehugger
Change-Id: Iee1b9d763ead15eef3d2c33666b3403b68940c3c
r325389 | kib | 2017-11-04 03:52:58 -0700 (Sat, 04 Nov 2017) | 7 lines
C++17 requires quick_exit(3) to be async-signal safe.
Make it safe, and update man page with the useful information.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Test: treehugger
Change-Id: Idf84b1f1e360c031b0e39d5f6e80d17308db1940
Originally a BSD extension, now in glibc too. We've used it internally
for a while.
(cherry-pick of e4b13f7e3ca68edfcc5faedc5e7d4e13c4e8edb9.)
Bug: http://b/112163459
Test: ran tests
Change-Id: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
Merged-In: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
This is the FreeBSD implementation, plus some tests. The FreeBSD
implementation includes the GNU extensions and seems to be what
iOS is using too, which should provide bug compatibility for app
developers.
The code unfortunately uses a lot of stack, and uses FreeBSD locale
implementation that we don't have, but it does seem better maintained
than the other BSDs.
Bug: http://b/29251134
Test: ran tests
Change-Id: Ie477b45e42a6df1319b25712098519d2b33adf67
This means all our stdio implementation is now the OpenBSD implementation.
The only thing we lose is the STDIO_THREAD_LOCK calls but they were no-ops
anyway.
We should probably talk to upstream about this. Either fix the locking or,
preferably, encourage them to move away from this pooling (especially since
there's no eviction policy).
Bug: 17154680
Change-Id: Ie2523e444a7d0965b8d141d57e3e11f6432d5b9a
