Joan Lledó <joanlluisll...@gmail.com> writes: > Since Glibc calls the io_select() operation each time the user > calls send() or recv(), in practice such sockets are just > unusable.
Too bad there is no lwip_poll function. Might the LwIP folks be amenable to adding one? > [3] > https://github.com/jlledom/lwip-hurd/commit/ad7bf3a9342c9e75e042ce1040797392b98d24df Your size calculations seem wrong. glibc defines fd_mask = __fd_mask = long int. FD_SETSIZE is the number of bits that fit in fd_set. But then lwip_selscan does size_t setsize = ((maxfdp1 / (8*(int)sizeof(fd_mask))) + 1) > FD_SETSIZE ? ((maxfdp1 / (8*(int)sizeof(fd_mask))) + 1) : FD_SETSIZE; fd_mask lreadset[setsize], lwriteset[setsize], lexceptset[setsize]; [...] memset(&lreadset, 0, setsize); which has two bugs: * It treats FD_SETSIZE as the minimum number of fd_mask elements, even though it was supposed to be the number of bits. That seems to waste some memory, but it isn't serious. * It clears only the first setsize bytes of each array. It should be doing memset(&lreadset, 0, setsize * sizeof(fd_mask)). Likewise in the memcpy calls later. This seems likely to cause real problems. lwip_io_select_common has similar bugs plus it seems to leak lreadset, lwriteset, or lexceptset in some cases. I wonder how hard it would be to implement those select ops in the translator without hogging a thread for each.
