How about mailboxes? Does LwIP require multiple waiting threads on a mailbox? That would require some substantial rewriting of our OS mailbox system. I think it would be pretty straight forward to add support for semaphore/mailbox deallocation to our OS, so that is not a very big issue.
Regards, Timmy Brolin [email protected] wrote: > If I remember correctly, there are many places in the stack where your > simple semaphore can be used (tcpip_thread, netconn semaphores, etc.) > but there are also other usages where multiple waiting threads have to > be supported (i.e. locking the heap in mem_malloc). So I guess you are > right that the generic sys_sem_t must be the multiple-type. > > Speaking of deallocation: I also ran lwIP on an OS which didn't > support this. I ended up in having a preallocated list/array of > mboxes/semaphores and returning an instance of that list in > sys_sem_new(). > > Simon > > > Timmy Brolin wrote: >> Hello, >> I have A few questions about LwIP OS requirements.. >> >> Our operating system provides two kinds of semaphores. The normal (and >> resource-light) semaphore only allows a single task to block on it at >> any one time. There is also a second type which allows multiple tasks to >> block on it at the same time, but it requires a bit more memory >> resources. >> Am I correct in assuming that LwIP requires multiple tasks to block on >> the same semaphore? Are there any semaphores in LwIP which could do with >> the simpler semaphore type? >> >> The mailbox system in our operating system is based on the standard >> semaphores, so only one task may block on a mailbox at any one time. Is >> this acceptable for LwIP? >> >> Our OS has a limitation in that semaphores and mailboxes never can be >> deallocated, and I was hoping that the addition of a deallocation >> funtion for semaphores and mailboxes would be enough to get LwIP running >> on our system. I would prefer not having to write a new mailbox system >> as well.. :-) >> >> Regards, >> Timmy Brolin >> >> >> _______________________________________________ >> 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
