We are observing one weird problem when sending message of size more than 65536 bytes using boost asynch_write on Solaris (though the problem is not observed on Linux). We are using boost version 1.47 with studio 12 CC compiler (on Solaris) and g++ 4.4.3 (on Linux). When a message of size more than 65536 (sometimes we are observing the issue with around 50K bytes size also but with 65536 bytes the issue is always reproducible) is sent, the message is delivered correctly to the receiver. But once the message is sent, the io service thread on the sender side goes into busy-wait loop. "truss" on the sender pid shows the following calls continuously. /6: recvmsg(57, 0xFFFFFD7FEB9FDDF0, 0) Err#11 EAGAIN /6: write(13, " 9\0\0\019\0\0\0", 8) = 8 /6: ioctl(13, DP_POLL, 0xFFFFFD7FEB9FE460) = 1 /6: recvmsg(57, 0xFFFFFD7FEB9FDDF0, 0) Err#11 EAGAIN /6: write(13, " 9\0\0\019\0\0\0", 8) = 8 /6: ioctl(13, DP_POLL, 0xFFFFFD7FEB9FE460) = 1 /6: recvmsg(57, 0xFFFFFD7FEB9FDDF0, 0) Err#11 EAGAIN /6: write(13, " 9\0\0\019\0\0\0", 8) = 8 /6: ioctl(13, DP_POLL, 0xFFFFFD7FEB9FE460) = 1 /6: recvmsg(57, 0xFFFFFD7FEB9FDDF0, 0) Err#11 EAGAIN /6: write(13, " 9\0\0\019\0\0\0", 8) = 8 /6: ioctl(13, DP_POLL, 0xFFFFFD7FEB9FE460) = 1 /6: recvmsg(57, 0xFFFFFD7FEB9FDDF0, 0) Err#11 EAGAIN /6: write(13, " 9\0\0\019\0\0\0", 8) = 8 /6: ioctl(13, DP_POLL, 0xFFFFFD7FEB9FE460) = 1 "lsof" shows that the socket descriptor 57 above is the socket descriptor corrected to the receiver. Thread 6 here is the ioservice thread whose stack trace is - thread t@6 -- ???????? thread_proxy boost::detail::thread_data<>::run des::tunnel::ServiceScheduler::processServiceWork boost::asio::io_service::run boost::asio::detail::task_io_service::run boost::asio::detail::task_io_service::do_one boost::asio::detail::dev_poll_reactor::run The busy-wait loop continues until we stop the receiver. Also, as mentioned, the issue is always reproducible if the size of the message more than 65536 (2^16) bytes and sender and receiver are running on 2 different Solaris hosts. If both sender and receiver are running on same Solaris host then the issue is always reproducible with size 131067 (2^17). Can someone throw some light on why the ioservice thread here is continuously trying to read from the receiver though it has successfully sent the message and receiver is not actually writing anything on the socket. Please let me know if anyone came across this problem or suggest any solution. Thanks Ranadheer -- View this message in context: http://boost.2283326.n4.nabble.com/Problem-with-asych-write-when-sending-mor... Sent from the Boost - Users mailing list archive at Nabble.com.