Is it safe to call async_write & async_read from different threads in situation when io_service::run() was called from only one thread? Thank you!
Sam Miller
Is it safe to call
async_write&async_readfrom different threads
Yes, but with a caveat. You can safely do this for distinct socket objects
Thread Safety
Distinct objects: Safe.
Shared objects: Unsafe.
The documentation is conservative on that and says "no".
But I'm doing this anyway in one of my linux programs and it seems to work fine. Digging into boost/asio/detail/epoll_reactor.ipp shows that the function start_op() is indeed protected by a mutex, so my confidence is increased.
But other platforms may be different..
来源：https://stackoverflow.com/questions/7639349/boost-asio-thread-safety