When FreeBSD didn't have gethostbyname_r(), and gethostbyname() wasn't
thread-safe, Marc asked around and found out that the threaded solution
for this is to use getaddrinfo(). This makes sense because
getaddrinfo() is described as:
getaddrinfo () function is defined for protocol-independent nodename-to-address translation. It performs functionality
ofgethostbyname(3)and getservbyname(3), in more sophisticated manner.
A number of platforms have getpwuid_r(), but not gethostbyname_r(). I
now realize it is because they are assuming you arew using getaddrinfo(),
which has freeaddrinfo() to free the allocated memory in a thread-safe
manner.
Right now, we call gethostname() from two places:
port/getaddrinfo() (if backend)port/thread.c::pqGethostbyname()
and pqGethostbyname() (thread-safe) is called only by:
port/getaddrinfo() (if frontend)libpq/fe-secure.c
If we convert fe-secure.c to use getaddrinfo(), then all host address
lookups go through getaddrinfo().
Then, if we don't need our port/getaddrinfo(), we don't care about a
non-thread-safe gethostbyname() on that platform. This improves our
thread-safe support. Specifically, it prevents host name lookups from
be serialized by our pthread locks.
Once everything goes through getaddrinfo(), I will modify my thread test
program to test gethostbyname() threading _only_ if getaddrinfo()
doesn't exist.
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square,
Pennsylvania19073
