David Hammerton <david...@gmail.com> wrote: > I need a bit of clarification on using lwip in a multi-threaded > environment. > The wiki page (http://lwip.wikia.com/wiki/LwIP_and_multithreading) is a > little vague, as is this email response: ( > http://www.mail-archive.com/lwip-users@nongnu.org/msg07800.html)
I agree abotu the wiki (in fact, the information there is somwhere between misleading and wrong), but what's vague about my email? "Both the netconn and the socket API are thread-safe as long as you don't share one netconn/socket between multiple threads (i.e. don't access it from more than one thread at a time)." What you want to do is sharing a connection between threads: one thread for reading, one thread for writing. That's not supported, simple as that. > By the looks of it, netconn_send goes > through a message (either using a lock or a message queue), so I think it > should be safe? That's what the wiki talks about, I guess. However, while this *might* work for UDP, it's not something it's supposed to do. If it works, it does so "by accident". > Also, how am I supposed to use the callback provided > to netconn_new_with_proto_and_callback? Should I/Can I be calling > netconn_recv in the thread context of the callback? If not, how can I > abort > a netconn_recv if, for example, I need to shut down the connection? The callback is used for socket select(), for example. It gets called from tcpip_thread, so if you implement your own callback, it has to be thread-safe. Using a select-like mechanism is usually the way to go with lwIP (instead of having different threads for TX/RX). Simon -- GMX DSL Doppel-Flat ab 19,99 Euro/mtl.! Jetzt mit gratis Handy-Flat! http://portal.gmx.net/de/go/dsl _______________________________________________ lwip-users mailing list lwip-users@nongnu.org http://lists.nongnu.org/mailman/listinfo/lwip-users
