[Click] Patch for nanosecond scheduling precision in ns-3-click

[Eddie Kohler]

Hi Lalith,

This is fair enough. But we could add a sim-command that returned 0 if 
the current timestamp is a timespec. On Ns-2 this command would return 
-1. Then we could do what's appropriate within click.

Eddie


On 1/9/12 3:33 PM, Lalith Suresh wrote:
> Hi Eddy,
>
> On Mon, Jan 9, 2012 at 7:05 PM, Eddie Kohler<ekohler at gmail.com>  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
>>>
>>
>
>
>