set close-on-exec for all sockets

[Jason Toffaletti]

libmemcached doesn't set close-on-exec so all of the file descriptors it creates are inherited by child processes. As far as I can tell, the children can't use these file descriptors for any useful purpose so its a resource leak.

all socket() calls should add " | SOCK_CLOEXEC" to the socket type argument. if the platform doesn't support SOCK_CLOEXEC, but children inherit parent fd, then SOCK_CLOEXEC can be defined to 0 to make the compiler happy, and fnctl can be used to set FD_CLOEXEC.

[Brian Aker (brianaker)]

I will be curious to see how many platforms this works on now a days :)

Thanks for pointing this out!