Re: [Xenomai-help] Passing data from device init to open function

[Johan Borkhuis <j.borkhuis@domain.hid>]

Jan Kiszka wrote:
>> This does work, but only as long as sizeof(int) == sizeof(<pointer>),
>> which is true on 32 bit systems, but not on 64 bit systems. So I would
>> like to add an extra pointer field to the rtdm_device structure,
>> pointing to some device-data to allow this to work on both 32 and 64 bit
>> systems.
>>     
> Hmm, that's what we had in an early RTDM version, but the more common
> use-case turned out to be
>
> per_device_data = my_per_device_data[device->device_id];
>
> where my_per_device_data is a global variable, typical a data structure
> containing all the required per-device information.
>   

I considered that as well. The main problem is that you have to 
statically allocate the memory based on the maximum number of devices 
you want to support, and I prefer to allocate the memory for each 
available device.

> Anyway, as you are adding this field, not replacing the ID with it, I
> think I'm going to merge this.
>   
One should have a very good reason to replace or remove a field in a 
system-structure, and this is just an addition to the structure, so no 
real need to replace anything.

Thanks.

Kind regards,
    Johan Borkhuis