In this section, synchronous socket operations are those
member functions specified as two overloads, with and without an argument
R f(A1 a1, A2 a2, ..., AN aN); R f(A1 a1, A2 a2, ..., AN aN, error_code& ec);
For an object
s, the conditions under which its synchronous
socket operations may block the calling thread (C++Std [defns.block]) are
determined as follows.
s.non_blocking() == true,
— the synchronous socket operation is specified in terms of a POSIX
function other than
— that POSIX function lists
EAGAIN in its failure conditions, and
— the effects of the operation cannot be established immediately
then the synchronous socket operation shall not block the calling thread. [Note: And the effects of the operation are not established. —end note]
Otherwise, the synchronous socket operation shall block the calling thread until the effects are established.