Re: Patch for nanosecond scheduling precision in ns-3-click

Hi Eddy,

On Mon, Jan 9, 2012 at 7:05 PM, Eddie Kohler <[email protected]> wrote:
> Hi Lalith,
>
> This change looks generally good, but surely ns defines some version
> variables that we can use to detect whether "cursimnode->curtime" is a
> timespec or a timeval. If it doesn't, then please add one: #define
> NS_CURTIME_IS_TIMESPEC 1. Then Click can be made to work cleanly with
> either, for instance:
>
> #if NS_CURTIME_IS_TIMESPEC
>  *ts = cursimnode->curtime;
> #else
>  ts->tv_sec = cursimnode->curtime.tv_sec;
>  ts->tv_nsec = cursimnode->curtime.tv_usec * 1000;
> #endif
>
> The timer scheduling code in routerthread.cc would also need a fork: #if
> CLICK_NS && NS_CURTIME_IS_TIMESPEC /timespec-code/ #elif CLICK_NS
> /timeval-code/ #endif.
>
> Make sense?
>

Nopes (or I'm way too tired). :)

I don't think a #define in ns-3 will help here. ns-3 links with
libnsclick.so dynamically, and "cursimnode->curtime" comes from
include/click/simclick.h (struct simclick_node). If we are to use the
preprocessor to fork the code appropriately, then we'd need to know
NS_CURTIME_IS_TIMESPEC during Click's compile time. Right?

> Sascha, did you end up trying this?
> Eddie
>
>
>
> On 12/31/11 7:46 AM, Lalith Suresh wrote:
>>
>> Hello all,
>>
>> After Sascha raised this issue on the ns-3-users list [1], I tried
>> making a quick patch to make Click's NS code use timespec, and make
>> the corresponding changes on the ns-3 side as well.
>>
>> I've pushed the changes to my ns-3-click [2] and Click [3]
>> repositories. Kindly review. I'll push to ns-3-dev once the Click side
>> changes are applied. Note that this will probably break the ns-2
>> patches for nsclick.
>>
>>
>> [1]
>> http://groups.google.com/group/ns-3-users/browse_thread/thread/2be8d60531bd82a8
>> [2] http://code.nsnam.org/lalith/ns-3-click-dev
>> [3] https://github.com/lalithsuresh/click
>>
>



-- 
Lalith Suresh
www.lalith.in