id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
11806	microsec_clock::universal_time() is needlessly slow	jzwinck@…	James E. King, III	"The [http://www.boost.org/doc/libs/1_55_0/doc/html/date_time/posix_time.html documentation] for `microsec_clock::universal_time()` says: 

> Get the UTC time using a sub second resolution clock. On Unix systems this is implemented using !GetTimeOfDay.

In fact it is implemented partly using `gettimeofday()` but also `gmtime_r()`.  Once you unwrap all the layers, the flow is something like this:

    sec,nsec = gettimeofday()
    date,time = gmtime(sec)
    sec,nsec = ptime(date,time)
    return sec+nsec/1000

The problem is that `gmtime_r()` is very slow, relative to the other operations involved here, and it is completely unnecessary.  A call to `gettimeofday()` on Unix is all you need to implement `universal_time()`."	Bugs	closed	To Be Determined	date_time	Boost 1.55.0	Optimization	wontfix