1.5.0 - gettimeofday() out of sync with Windows time

[Larry Hall]

Christopher Faylor wrote:

> On Thu, Jul 17, 2003 at 05:53:02PM -0400, Larry Hall wrote:
> 
>>Chris Church wrote:
>>
>>
>>>I'm using version 1.5.0 of the cygwin1.dll on Windows 2000 
>>>Professional.  I've also seen the problem described below on earlier 
>>>versions of cygwin (1.3.22).
>>>
>>>I've found that the gettimeofday() and ftime() functions do not always 
>>>return the correct system time as reported by Windows.  The time() 
>>>function, however, always remains in sync with Windows time.  This 
>>>discrepancy occurs when an application is started, then the Windows 
>>>system time changes, then the application calls gettimeofday() or 
>>>ftime() to retrieve the current system time.   Both gettimeofday() and 
>>>ftime() always report the same incorrect time.  It also appears that the 
>>>time as reported by gettimeofday() and ftime() is based on a counter 
>>>that is initialized to match the system time, but once started, 
>>>increments at a constant rate regardless of any changes to the Windows 
>>>time.  (I have not yet dug into the source for Cygwin to see how these 
>>>functions are implemented.)  Finally, the time reported by 
>>>gettimeofday() and ftime(), when used within an application that runs 
>>>for an extended period of time, will drift from the Windows time.
>>>
>>>Is this a known issue with Cygwin, and are there any patches available?
>>
>>Not yet.  But this was mentioned on the developer's list this morning
>>and someone is looking at the problem.
> 
> 
> Sorry, no, no one is looking at the problem.  It's been a known problem
> since the implementation.


I stand corrected.  Rereading the thread, I see that it simply mentions
this problem relative to another line of investigation.  So dig in! :-)


-- 
Larry Hall                              http://www.rfk.com
RFK Partners, Inc.                      (508) 893-9779 - RFK Office
838 Washington Street                   (508) 893-9889 - FAX
Holliston, MA 01746


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/