From fe2ae4f877928dd6bff5bac3f15bce4b50d2bd12 Mon Sep 17 00:00:00 2001 From: Khem Raj Date: Wed, 18 Mar 2015 00:51:16 +0000 Subject: [PATCH 21/27] eglibc: cherry-picked from http://www.eglibc.org/archives/patches/msg00772.html It hasn't yet been merged into glibc Upstream-Status: Pending Signed-off-by: Khem Raj --- resolv/res_libc.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/resolv/res_libc.c b/resolv/res_libc.c index ee3fa21..29e2340 100644 --- a/resolv/res_libc.c +++ b/resolv/res_libc.c @@ -22,12 +22,13 @@ #include #include #include - +#include /* The following bit is copied from res_data.c (where it is #ifdef'ed out) since res_init() should go into libc.so but the rest of that file should not. */ +__libc_lock_define_initialized (static, lock); extern unsigned long long int __res_initstamp attribute_hidden; /* We have atomic increment operations on 64-bit platforms. */ #if __WORDSIZE == 64 @@ -35,7 +36,6 @@ extern unsigned long long int __res_initstamp attribute_hidden; # define atomicincunlock(lock) (void) 0 # define atomicinc(var) catomic_increment (&(var)) #else -__libc_lock_define_initialized (static, lock); # define atomicinclock(lock) __libc_lock_lock (lock) # define atomicincunlock(lock) __libc_lock_unlock (lock) # define atomicinc(var) ++var @@ -94,7 +94,18 @@ res_init(void) { int __res_maybe_init (res_state resp, int preinit) { + static time_t last_mtime; + struct stat statbuf; + int ret; + if (resp->options & RES_INIT) { + ret = stat (_PATH_RESCONF, &statbuf); + __libc_lock_lock (lock); + if ((ret == 0) && (last_mtime != statbuf.st_mtime)) { + last_mtime = statbuf.st_mtime; + atomicinc (__res_initstamp); + } + __libc_lock_unlock (lock); if (__res_initstamp != resp->_u._ext.initstamp) { if (resp->nscount > 0) __res_iclose (resp, true); -- 2.1.4