Re: BUG #14720: getsockopt(TCP_KEEPALIVE) failed: Option not supported by protocol

I wrote:
> Concretely, something like the attached. I have no way to test this
> locally, so I'm thinking of just pushing it and seeing what the buildfarm
> says.

So that didn't work: castoroides is still showing

[5953a7e1.1fff:13] LOG: getsockopt(TCP_KEEPALIVE) failed: Option not supported by protocol
[5953a7e1.1fff:14] STATEMENT: select name, setting from pg_settings where name like 'enable%';

which implies that TCP_KEEPALIVE_THRESHOLD doesn't exist on Solaris 10.
Evidently, the logic here needs to be along the lines of

#if defined(TCP_KEEPIDLE)
...
#elif defined(TCP_KEEPALIVE_THRESHOLD)
...
#elif defined(TCP_KEEPALIVE) && defined(__darwin__)
...

Or we could make the last test be !defined(__solaris__), but I'm not
sure that's better. Anybody have an opinion?

As long as I have to touch this code again anyway, I'm also going to
look into Michael's thought of trying to reduce code duplication.
I was unhappy yesterday about how to handle the error messages,
but we could do it like this:

#if defined(TCP_KEEPIDLE)
#define PG_TCP_KEEPALIVE TCP_KEEPIDLE
#define PG_TCP_KEEPALIVE_STR "TCP_KEEPIDLE"
#elif ...

#ifdef PG_TCP_KEEPALIVE
if (setsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE,
(char *) &idle, sizeof(idle)) < 0)
{
elog(LOG, "setsockopt(%s) failed: %m", PG_TCP_KEEPALIVE_STR);

which doesn't seem too painful.

regards, tom lane