In a project using asio I noticed performance issues on Sun vs. Linux. It turned out that dev_poll_reactor is doing tones of system calls always pairs of write() and ioctl(). Stranger still is that the calls to write() are for 0 bytes. I was able to avoid the issue by switching from strand to mutex. I think there is some bug or logic error in dev_poll_reactor so I wrote a test program to narrow down when it happens: // Christopher Hite RTS Realtime Systems Software GmbH, Rembrandtstrasse 13, D-60596 Frankfurt am Main T: +49.69.61009.0 / F: +49.69.61009.181 Sitz: Frankfurt am Main - HRB 84467 Amtsgericht Frankfurt am Main Geschäftsführer: Steffen Gemuenden, Igor Sluga www.rtsgroup.net This email and any attachments are for the exclusive and confidential use of the intended recipient. If you are not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, please do not read, distribute or take action in reliance upon this message. If you have received this in error, please notify me immediately by return email and promptly delete this message and its attachments from your computer system. ------------------------------------------------------------------------------- #include #include <iostream> using namespace boost::asio; io_service service; io_service::strand strand_(service); local::stream_protocol::socket s0(service); local::stream_protocol::socket s1(service); void wh(const boost::system::error_code& ec,const std::size_t){ if(ec) std::cout<