resolv: Automatically reload a changed /etc/resolv.conf file [BZ #984]

This commit enhances the stub resolver to reload the configuration
in the per-thread _res object if the /etc/resolv.conf file has
changed.  The resolver checks whether the application has modified
_res and will not overwrite the _res object in that case.

The struct resolv_context mechanism is used to check the
configuration file only once per name lookup.

1 files changed, 0 insertions, 18 deletions

diff --git a/resolv/res_libc.c b/resolv/res_libc.c
index 5066983..9f2d3c3 100644
--- a/resolv/res_libc.c
+++ b/resolv/res_libc.c
@@ -42,18 +42,6 @@
 #include <libc-lock.h>
 #include <resolv-internal.h>
 
-/* We have atomic increment operations on 64-bit platforms.  */
-#if __WORDSIZE == 64
-# define atomicinclock(lock) (void) 0
-# 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
-#endif
-
 int
 res_init (void)
 {
@@ -90,12 +78,6 @@ res_init (void)
   if (!_res.id)
     _res.id = res_randomid ();
 
-  atomicinclock (lock);
-  /* Request all threads to re-initialize their resolver states,
-     resolv.conf might have changed.  */
-  atomicinc (__res_initstamp);
-  atomicincunlock (lock);
-
   return __res_vinit (&_res, 1);
 }