timer: use mach_absolute_time as high resolution clock on darwin

Not guaranteed to be in nanosecond resolution. On iOS 7 the duration
of one tick is 125/3 ns which is still more than an order of magnitude
better then microseconds.

Replace decicycles with the neutral UNITS. Decicycles is strange but
tenths of a nanosecond and unspecific "deci"-ticks for mach_absolute_time
is just silly.
This commit is contained in:
Janne Grunau 2014-01-24 01:15:31 +01:00 committed by Janne Grunau
parent 634d9d8b39
commit c708b54033
2 changed files with 15 additions and 3 deletions

4
configure vendored
View File

@ -1387,6 +1387,8 @@ HAVE_LIST="
local_aligned_8
localtime_r
loongson
mach_absolute_time
mach_mach_time_h
machine_ioctl_bt848_h
machine_ioctl_meteor_h
machine_rw_barrier
@ -3853,6 +3855,7 @@ check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss
check_func gettimeofday
check_func isatty
check_func localtime_r
check_func mach_absolute_time
check_func ${malloc_prefix}memalign && enable memalign
check_func mkstemp
check_func mmap
@ -3887,6 +3890,7 @@ check_header dlfcn.h
check_header dxva.h
check_header dxva2api.h
check_header io.h
check_header mach/mach_time.h
check_header malloc.h
check_header poll.h
check_header sys/mman.h

View File

@ -32,6 +32,10 @@
#include "config.h"
#if HAVE_MACH_MACH_TIME_H
#include <mach/mach_time.h>
#endif
#include "log.h"
#if ARCH_ARM
@ -44,8 +48,12 @@
# include "x86/timer.h"
#endif
#if !defined(AV_READ_TIME) && HAVE_GETHRTIME
#if !defined(AV_READ_TIME)
# if HAVE_GETHRTIME
# define AV_READ_TIME gethrtime
# elif HAVE_MACH_ABSOLUTE_TIME
# define AV_READ_TIME mach_absolute_time
# endif
#endif
#ifdef AV_READ_TIME
@ -68,7 +76,7 @@
tskip_count++; \
if (((tcount + tskip_count) & (tcount + tskip_count - 1)) == 0) { \
av_log(NULL, AV_LOG_ERROR, \
"%"PRIu64" decicycles in %s, %d runs, %d skips\n", \
"%"PRIu64" UNITS in %s, %d runs, %d skips\n", \
tsum * 10 / tcount, id, tcount, tskip_count); \
} \
}