Re: Windows 2000 problems
Thank you for your response. I apologize, my description of the delay_loop
problem might have been misleading. Hope this one gives a better picture:
Say I want to send UDP datagrams at bit rates which require a delay of
200 microseconds between successive datagrams. The environment in which
I am trying this experiment (Windows 2000 v5 sp2 on NT FAT32, and I am
compiling using Visual Studio 6.0) provides me with a resolution of 10
milliseconds for file times. delay_loop function uses getTimeofday function,
which in turn uses getSysTimeasFileTime (the resolution of which is 10 ms).
So after the first datagram is sent, instead of 200 microseconds, I get 10
milliseconds of delay from the delay_loop before the next datagram
can be sent.
I dont know whether I can get better resolutions on NTFS. I am working on that
right now and will let you know. If you have any suggestions, or know that
I might be missing something, please let me know.
Thanks,
Vinay.
> I have no experience with the cygwin environment so I can not help you
> out. I use Visual Studio .Net to compile win32 versions and the next
> release will include a .vcproj that can be used with VS .NET.
>
> How are you measuring the resolution of delay_loop? I am not sure how you
> are deciding that the gettimeofday granularity is some how based on the
> delay_loop function since it is not. A time of day function is completely
> OS specific and I would doubt they would allow tweaking of its
> responsiveness. Also there are some floating point to long conversions
> that may be removing some of the detail you are looking for.
>
> Kevin
>
> On Fri, 14 Feb 2003, Vinay Chandrasekhar wrote:
>
> > hello,
> > I have a couple of questions, and would greatly appreciate any suggestions
> > or advice ..
> > 1. I am unable to compile the latest version (1.6.5) of iPerf on Windows 2000. I
> > am trying to compile the source code in a cygwin window - I have
> > installed the base cygwin and accompanying gcc - and I get the following
> > error:
> >
> > In file included from gnu_getopt.c:75:
> > gnu_getopt.h:95: redefinition of `struct option'
> > make[1]: *** [gnu_getopt.o] Error 1
> > make[1]: Leaving directory `/cygdrive/c/vinay/thesis/snmp/software/traffic/compi
> > le/lib'
> > make: *** [lib/libdast.a] Error 2
> >
> > What am I doing wrong? Is there any other way to compile iPerf in windows 2000?
> > I also have MS Visual Studio... I tried finding the answers to this
> > elsewhere, but havent had success so far.
> >
> > 2. I am trying to test whether it is possible to send UDP datagrams at different
> > time instants(VBR, to some extent) using iPerf. The maximum resolution
> > that windows is currently giving me for the delay_loop() function, and
> > consequently the gettimeofday() function is about 10015 microseconds
> > (about 10 mSecs). Is there a setting that I could change somewhere, and
> > make it work better?
> >
> > Thank you,
> > Vinay.
> >
>
>
>