Make it much more understandable, add a missing
iov_cnt argument (number of iovs in the iov), and
add comments to it.
The new implementation has been extensively tested
by splitting a large buffer into many small
randomly-sized chunks, sending it over socket to
another, slow process and verifying the receiving
data is the same.
Also add a unit test for iov_send_recv(), sending/
receiving data between two processes over a socketpair
using random vectors and random sizes.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
25e5e4c7e9