hi, Thanks for your reply. I cancel the read/write on a tcp connection because the current node I connected to may be too busy to response, so I can try another node. I do not want cancel all async request because the other pending operations may finish successfully, the workload on peer node is very heavy instead of failure. Anyway, I can cancel all request, but I still have the question about the cancel. What if I cancel all the async operation, is there any partial data which has been read from or write to socket after the cancelation? If partial data has been read from or write to socket, how can I issue both async read/write again? Best Regards Zhanwei Wang ----- Original Message -----From: Igor R To: boost-users@lists.boost.org

My question is: the "cancel" call acutely cancel all the pending async operation, but only one of them is timeout. For example, there is a pending async read and a pending async write operation, only read is timeout, I do not want cancel write any way.

Yes, you're right. You'll have to issue both async read and write again. But usually "timeout" means that something goes wrong with the connection (i.e. you expected something, but it failed to happen). _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users