joyent/libuv — pull request #1325 by indutny (2014-06-19 15:29:36+00:00)
Title: darwin: invoke `mach_timebase_info` only once

According to @aktau, the call to `mach_timebase_info` costs 90% of the
total execution time of `uv_hrtime()`. The result of the call is static
on all existing platforms, so there is no need in invoking it multiple
times.