[vlc-devel] commit: mtime: Use mach_absolute_time on Mac OS X instead of gettimeofday. (Pierre d'Herbemont )

[Pierre d'Herbemont]

Feel free to forward port. I can't get a usable vlc-1.0 here to test on.

On Sun, Feb 8, 2009 at 1:03 AM, git version control <git at videolan.org> wrote:
> vlc | branch: 0.9-bugfix | Pierre d'Herbemont <pdherbemont at videolan.org> | Sun Feb  8 00:31:33 2009 +0100| [5ead92ffd58088828ed802173d963b2571f0cd69] | committer: Pierre d'Herbemont
>
> mtime: Use mach_absolute_time on Mac OS X instead of gettimeofday.
>
> mach_absolute_time() is a monotic clock, whereas gettimeofday() is not. For that reason setting your computer time while playing a movie won't halt playback anymore.
>
> Seems to fix the dropped frame issue on Mac OS X.
>
>> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=5ead92ffd58088828ed802173d963b2571f0cd69
> ---
>
>  include/vlc_threads.h |   14 ++++++++++++++
>  src/misc/mtime.c      |   34 ++++++++++++++++++++++++++++++++++
>  2 files changed, 48 insertions(+), 0 deletions(-)
>
> diff --git a/include/vlc_threads.h b/include/vlc_threads.h
> index e2810e9..8a21f84 100644
> --- a/include/vlc_threads.h
> +++ b/include/vlc_threads.h
> @@ -359,12 +359,26 @@ static inline void __vlc_cond_wait( const char * psz_file, int i_line,
>  #define vlc_cond_timedwait( P_COND, P_MUTEX, DEADLINE )                      \
>     __vlc_cond_timedwait( __FILE__, __LINE__, P_COND, P_MUTEX, DEADLINE  )
>
> +#ifdef __APPLE__
> +# include <sys/time.h> /* gettimeofday in vlc_cond_timedwait */
> +#endif
> +
>  static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
>                                         vlc_cond_t *p_condvar,
>                                         vlc_mutex_t *p_mutex,
>                                         mtime_t deadline )
>  {
>  #if defined(LIBVLC_USE_PTHREAD)
> +#ifdef __APPLE__
> +    /* mdate() is mac_absolute_time on osx, which we must convert to do
> +     * the same base than gettimeofday() on which pthread_cond_timedwait
> +     * counts on. */
> +    mtime_t oldbase = mdate();
> +    struct timeval tv;
> +    gettimeofday(&tv, NULL);
> +    mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
> +    deadline = deadline - oldbase + newbase;
> +#endif
>     lldiv_t d = lldiv( deadline, 1000000 );
>     struct timespec ts = { d.quot, d.rem * 1000 };
>
> diff --git a/src/misc/mtime.c b/src/misc/mtime.c
> index 6c13eac..ed65f03 100644
> --- a/src/misc/mtime.c
> +++ b/src/misc/mtime.c
> @@ -60,6 +60,11 @@
>  #   include <sys/time.h>
>  #endif
>
> +#ifdef __APPLE__
> +#   include <mach/mach.h>
> +#   include <mach/mach_time.h>
> +#endif
> +
>  #if !defined(HAVE_STRUCT_TIMESPEC)
>  struct timespec
>  {
> @@ -172,6 +177,15 @@ static inline unsigned mprec( void )
>  #endif
>  }
>
> +#ifdef __APPLE__
> +static mach_timebase_info_data_t mtime_timebase_info;
> +static pthread_once_t mtime_timebase_info_once = PTHREAD_ONCE_INIT;
> +static void mtime_init_timebase(void)
> +{
> +    mach_timebase_info(&mtime_timebase_info);
> +}
> +#endif
> +
>  /**
>  * Return high precision date
>  *
> @@ -197,6 +211,16 @@ mtime_t mdate( void )
>  #elif defined( HAVE_KERNEL_OS_H )
>     res = real_time_clock_usecs();
>
> +#elif defined( __APPLE__ )
> +    pthread_once(&mtime_timebase_info_once, mtime_init_timebase);
> +    uint64_t date = mach_absolute_time();
> +
> +    /* Convert to nanoseconds */
> +    date *= mtime_timebase_info.numer;
> +    date /= mtime_timebase_info.denom;
> +
> +    /* Convert to microseconds */
> +    res = date / 1000;
>  #elif defined( WIN32 ) || defined( UNDER_CE )
>     /* We don't need the real date, just the value of a high precision timer */
>     static mtime_t freq = INT64_C(-1);
> @@ -340,6 +364,11 @@ void mwait( mtime_t date )
>         ts.tv_sec = d.quot; ts.tv_nsec = d.rem * 1000;
>         while( clock_nanosleep( CLOCK_REALTIME, 0, &ts, NULL ) == EINTR );
>     }
> +#elif defined( __APPLE__ ) /* The version that should be used, if it was cancelable */
> +    pthread_once(&mtime_timebase_info_once, mtime_init_timebase);
> +    uint64_t mach_time = date * 1000 * mtime_timebase_info.denom / mtime_timebase_info.numer;
> +    mach_wait_until(mach_time);
> +
>  #else
>
>     mtime_t delay = date - mdate();
> @@ -385,6 +414,11 @@ void msleep( mtime_t delay )
>
>     while( nanosleep( &ts_delay, &ts_delay ) && ( errno == EINTR ) );
>
> +#elif defined( __APPLE__ ) /* The version that should be used, if it was cancelable */
> +    pthread_once(&mtime_timebase_info_once, mtime_init_timebase);
> +    uint64_t mach_time = delay * 1000 * mtime_timebase_info.denom / mtime_timebase_info.numer;
> +    mach_wait_until(mach_time + mach_absolute_time());
> +
>  #else
>     struct timeval tv_delay;
>
>
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> http://mailman.videolan.org/listinfo/vlc-devel
>