>Does it really need to know the 'type' of message, or does it just need the >size of the message. I'm thinking that if you added a size argument, the >sys_arch_mbox_post could copy the >right amount of data to the other process's >mbox. Internally, it could keep the size in the mbox structure to hide that >from the user. The task would then be to edit the core to call: >sys_mbox_post(mbox,msg, sizeof(msg)) instead of sys_mbox_post(mbox,msg).
>This might even be done by a #define. >What do you think? Can you be a little more specific? What do u mean, when u say just post a message. This isnt clear to me implementation wise, :( According to me, i was thinking of setting a shared memory segment b/w processes through shmget, but implementation wise i dont get it how my idea would work. A little help from you, and i might able to get through. Thanks Sandy On Dec 14, 2008, at 12:33 PM, sandy tewari wrote: > Thanks for your quick reply! I am going to think more over it and come back. > -Sandy > > From: "[email protected]" <[email protected]> > To: Mailing list for lwIP users <[email protected]> > Sent: Sunday, December 14, 2008 3:58:51 AM > Subject: Re: [lwip-users] LWIP Process Model confusion: > > sandy tewari wrote: > > Thanks for your help guys. So i am trying to implement it. > > Things that i need to do: > > > > 1. change sys_arch.c to work on processes not threads: i am going to exec a > > process now, rather than p_thread_create > > 2. secondly, i want to make them share common data: is that only going to > > be on mailboxes? so i just have to make a way to attach sys_mbox_new > > data on to shared memory? > > 3. What about the pcb connection information? Don't they would want to > > share too? it will be great to know which structure to include in? > > netconn? > > I don't want to bring you down, but I guess implementing this might not be as > easy as you think and might involve changing some of the lwIP core code > (which is normally not a good idea since you lose the option to just upgrade > to new versions). > > As I said before, the problem is that sys_arch_mbox_post does NOT know which > kind of data it shall post. Therefore, without changing this, you would have > to move ALL memory passed through mboxes (e.g. pbufs, apimsg, etc.) to shared > memory - although this might not work at all since some of this data is > located on the stack of a socket thread! > > To get it working properly, a change in the lwIP code is necessary: we would > have to move from generic message passing that relies on pointers to a more > specific way: if sys_arch_mbox_post would know the type of data to post, it > could (in multiprocess environments) copy the data insted of passing a > pointer and posting it to another process. If you create a good working patch > for this which does not interfere with multi_threading_, I guess chances > would be high it gets included in the main source. But I doubt any of the > active developers finds the time to do this for you :-( > > > Simon > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
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