On 05/21/2014 07:26 AM, Daniel P. Berrange wrote:
On Wed, May 21, 2014 at 04:16:29PM +0300, Laine Stump wrote:
Since there isn't a single libc API to get this value, this patch supplies one which gets the value by grabbing current UTC, then converting that into a struct tm with localtime_r(), then back to a time_t using mktime; it again does the same operation, but using gmtime_r() instead (for UTC). It then subtracts utc time from the localtime, and finally adjusts if dst is set in the localtime timeinfo (because for some reason mktime doesn't take that into account).
I think we ought to be able to unit test this code to make sure it is doing what we want. ie setenv("TZ", "EDT") in the start of the test suite to force a predictable timezone, then check the delta is correct.
Even better than "EDT" (which is not POSIX-compliant), reuse what we have done in other situations where we want to guarantee a known non-zero timezone that uses just POSIX functionality: tests/qemuxml2argvtest.c: if (setenv("TZ", "VIR00:30", 1) < 0) { -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org