* nscd/nscd.h (struct database_dyn): Add prunelock field.

	* nscd/cache.c (prune_cache): Take prunelock before starting the
	work.  Just return in case it is already taken.

	(inet6_option_alloc): Now a simple wrapper around option_alloc.

ChangeLog

@@ -1,3 +1,9 @@
+2006-05-29  Ulrich Drepper  <drepper@redhat.com>
+
+	* nscd/nscd.h (struct database_dyn): Add prunelock field.
+	* nscd/cache.c (prune_cache): Take prunelock before starting the
+	work.  Just return in case it is already taken.
+
 2006-05-25  Ulrich Drepper  <drepper@redhat.com>
 
 	* nis/nis_removemember.c (nis_removemember): Avoid unnecessary
@@ -12,7 +18,7 @@
 	inet6_option_alloc.
 	* inet/inet6_option.c (option_alloc): Renamed from
 	inet6_option_alloc.  Made static.
-	(inet6_option_alloc): New a simple wrapper around option_alloc.
+	(inet6_option_alloc): Now a simple wrapper around option_alloc.
 	(inet6_option_append): Call option_alloc.
 	* include/netinet/in.h: Remove libc_hidden_proto for
 	inet6_option_alloc.

nscd/cache.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 1998, 1999, 2003, 2004, 2005 Free Software Foundation, Inc.
+/* Copyright (c) 1998, 1999, 2003-2005, 2006 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -198,6 +198,13 @@ prune_cache (struct database_dyn *table, time_t now)
   if (cnt == 0)
     return;
 
+  /* This function can be called from the cleanup thread but also in
+     response to an invalidate command.  Make sure only one thread is
+     running.  No need for the second to wait around.  */
+  if (pthread_mutex_trylock (&table->prunelock) != 0)
+    /* Te work is already being done.  */
+    return ;
+
   /* If we check for the modification of the underlying file we invalidate
      the entries also in this case.  */
   if (table->check_file)
@@ -455,4 +462,6 @@ prune_cache (struct database_dyn *table, time_t now)
   /* Run garbage collection if any entry has been removed or replaced.  */
   if (any)
     gc (table);
+
+  pthread_mutex_unlock (&table->prunelock);
 }

nscd/nscd.h

@@ -58,6 +58,7 @@ typedef enum
 struct database_dyn
 {
   pthread_rwlock_t lock;
+  pthread_mutex_t prunelock;
 
   int enabled;
   int check_file;