Merge remote-tracking branch 'public/feature24427'

This commit is contained in:
Nick Mathewson 2017-12-11 09:59:46 -05:00
commit ea929e8456
4 changed files with 24 additions and 0 deletions

5
changes/feature24427 Normal file
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@ -0,0 +1,5 @@
o Minor features (OSX, iOS, performance):
- Use the mach_approximate_time() function (when available) to
implement coarse monotonic time. Having a coarse time function
should avoid a large number of system calls, and improve
performance slightly, especially under load. Closes ticket 24427.

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@ -506,6 +506,7 @@ AC_CHECK_FUNCS(
llround \
localtime_r \
lround \
mach_approximate_time \
memmem \
memset_s \
pipe \

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@ -314,6 +314,21 @@ monotime_get(monotime_t *out)
out->abstime_ = mach_absolute_time();
}
#if defined(HAVE_MACH_APPROXIMATE_TIME)
void
monotime_coarse_get(monotime_coarse_t *out)
{
#ifdef TOR_UNIT_TESTS
if (monotime_mocking_enabled) {
out->abstime_ = (mock_time_nsec_coarse * mach_time_info.denom)
/ mach_time_info.numer;
return;
}
#endif /* defined(TOR_UNIT_TESTS) */
out->abstime_ = mach_approximate_time();
}
#endif
/**
* Return the number of nanoseconds between <b>start</b> and <b>end</b>.
*/

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@ -65,6 +65,9 @@ typedef struct monotime_t {
typedef struct monotime_coarse_t {
uint64_t tick_count_;
} monotime_coarse_t;
#elif defined(__APPLE__) && defined(HAVE_MACH_APPROXIMATE_TIME)
#define MONOTIME_COARSE_FN_IS_DIFFERENT
#define monotime_coarse_t monotime_t
#else
#define monotime_coarse_t monotime_t
#endif /* defined(CLOCK_MONOTONIC_COARSE) && ... || ... */