[Mesa-dev] [PATCH 03/25] threads: update for late C11 changes

[Emil Velikov]

Hi Nicolai,

On 22 October 2017 at 20:07, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> C11 threads were changed to use struct timespec instead of xtime, and
> thrd_sleep got a second argument.
>
As xtime was replaced with timespec there's a couple of odd bits in the code.


> See http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1554.htm and
> http://en.cppreference.com/w/c/thread/{thrd_sleep,cnd_timedwait,mtx_timedlock}
>
> Note that cnd_timedwait is spec'd to be relative to TIME_UTC / CLOCK_REALTIME.
>
> Cc: Jose Fonseca <jfonseca at vmware.com>
> ---
>  include/c11/threads.h           | 11 -----------
>  include/c11/threads_posix.h     | 39 +++++++++++++++------------------------
>  include/c11/threads_win32.h     | 37 +++++++++++++++++++------------------
>  src/egl/drivers/dri2/egl_dri2.c | 24 +++++++++++++-----------
>  4 files changed, 47 insertions(+), 64 deletions(-)
>
> diff --git a/include/c11/threads.h b/include/c11/threads.h
> index 573348d8091..3c3f23a8ab8 100644
> --- a/include/c11/threads.h
> +++ b/include/c11/threads.h
> @@ -23,42 +23,31 @@
>   * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
>   * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
>   * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
>   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
>   * DEALINGS IN THE SOFTWARE.
>   */
>  #ifndef EMULATED_THREADS_H_INCLUDED_
>  #define EMULATED_THREADS_H_INCLUDED_
>
>  #include <time.h>
> -#ifdef _MSC_VER
> -#include <thr/xtimec.h>  // for xtime
> -#endif
>
>  #ifndef TIME_UTC
>  #define TIME_UTC 1
>  #endif
>
>  #include "c99_compat.h" /* for `inline` */
>
>  /*---------------------------- types ----------------------------*/
>  typedef void (*tss_dtor_t)(void*);
>  typedef int (*thrd_start_t)(void*);
>
> -#ifndef _MSC_VER
> -struct xtime {
> -    time_t sec;
> -    long nsec;
> -};
> -typedef struct xtime xtime;
> -#endif
> -

We don't have a fall-back declaration of the struct, yet we use it
below and provide a timespec_get() implementation.
I'd imagine you haven't tested this on Windows (hence Jose in CC)?

Quick search suggests that MSVC 2015 was the first one that introduces
the struct and timespec_get.

If we're safe as-is, please add a comment with some details - I'd
imagine Jose had better knowledge in the area.


>  /*-------------------- 7.25.7 Time functions --------------------*/
>  // 7.25.6.1
> +#if 0
I'd just drop the hunk mentioning that timespec_get() is part of time.h


Thank
Emil