net: use SO_LINGER_SEC on darwin

[mikioh]

a four and half year old bug.

% man 2 setsockopt on darwin

--
SO_LINGER controls the...

#define SO_LINGER 0x0080 /* linger on close if data present (in ticks) */
#define SO_LINGER_SEC 0x1080 /* linger on close if data present (in seconds) */

SO_LINGER_SEC is the same option as SO_LINGER except the linger time is in seconds for
SO_LINGER_SEC.
--

ticks... but fortunately no one knows what's the correct behavior to closing(*) a
SO_LINGER+O_NONBLOCK socket.

*) http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html

[gopherbot]

Comment 1:

CL https://golang.org/cl/92210044 mentions this issue.

[bradfitz]

Comment 2:

Please explain clearly what the bug is. You just copy/pasted some stuff here.

[ianlancetaylor]

Comment 3:

The bug is that setLinger takes a value in seconds, but the Darwin SO_LINGER setsockopt
option apparently takes a value in ticks.  To get a value in seconds, as on other Unix
systems, you apparently need to use SO_LINGER_SEC.

[mikioh]

Comment 4:

Thanks for the explanation, Ian. I filed issue #7974 for documentation errata.

[mikioh]

Comment 5:

This issue was closed by revision 900d49b.

Status changed to Fixed.

[bradfitz]

Comment 6:

This issue was closed by revision c91aea6.

[gopherbot]

Comment 7:

CL https://golang.org/cl/93250045 mentions this issue.