SO_SNDLOWAT is an option to set the minimum count for output operations. Most output operations process all of the data supplied by the call, delivering data to the protocol for transmission and blocking as neces- sary for flow control. Nonblocking output operations will process as much data as permitted subject to flow control without blocking, but will process no data if flow control does not allow the smaller of the low water mark value or the entire request to be processed. A select(2) operation testing the ability to write to a socket will return true only if the low water mark amount could be processed. The default value for SO_SNDLOWAT is set to a convenient size for network efficiency, often 1024.
http://www.freebsd.org/cgi/man.cgi?query=setsockopt&apropos=0&sektion...
Правильно ли я понимаю, что send на неблокируемом сокете вернет мне EAGAIN, если в буфере отправки сокета осталось свободного места меньше чем SO_SNDLOWAT?
