Update.

Jakub Jelinek  <jakub@redhat.com>

	* nscd/Makefile (nscd-modules): Add nscd_setup_thread.
	* nscd/connections.c (nscd_run): Call setup_thread for maintenance
	threads.
	* nscd/nscd-client.h (struct database_pers_head): Add
	nscd_certainly_running field.
	* nscd/nscd.h: Declare setup_thread.
	* nscd/nscd_helper.c (__nscd_get_map_ref): Avoid the time test if
	nscd_certainly_running is nonzero.

2004-09-08  Ulrich Drepper  <drepper@redhat.com>

ChangeLog

@@ -1,3 +1,15 @@
+2004-09-08  Ulrich Drepper  <drepper@redhat.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	* nscd/Makefile (nscd-modules): Add nscd_setup_thread.
+	* nscd/connections.c (nscd_run): Call setup_thread for maintenance
+	threads.
+	* nscd/nscd-client.h (struct database_pers_head): Add
+	nscd_certainly_running field.
+	* nscd/nscd.h: Declare setup_thread.
+	* nscd/nscd_helper.c (__nscd_get_map_ref): Avoid the time test if
+	nscd_certainly_running is nonzero.
+
 2004-09-08  Ulrich Drepper  <drepper@redhat.com>
 
 	* nscd/connections.c: Implement r/o sharing of nscd's cache with client

nscd/Makefile

@@ -31,7 +31,8 @@ vpath %.c ../locale/programs
 
 nscd-modules := nscd connections pwdcache getpwnam_r getpwuid_r grpcache \
 		getgrnam_r getgrgid_r hstcache gethstbyad_r gethstbynm2_r \
-		dbg_log nscd_conf nscd_stat cache mem xmalloc xstrdup
+		dbg_log nscd_conf nscd_stat cache mem nscd_setup_thread \
+		xmalloc xstrdup
 
 ifeq ($(have-thread-library),yes)
 

nscd/connections.c

@@ -770,6 +770,9 @@ nscd_run (void *p)
   time_t next_prune = run_prune ? time (NULL) + CACHE_PRUNE_INTERVAL : 0;
   static unsigned long int nready;
 
+  if (my_number < lastdb)
+    setup_thread (&dbs[my_number]);
+
   conn.fd = sock;
   conn.events = POLLRDNORM;
 

nscd/nscd-client.h

@@ -180,6 +180,7 @@ struct database_pers_head
   int version;
   int header_size;
   int gc_cycle;
+  int nscd_certainly_running;
   volatile time_t timestamp;
 
   size_t module;

nscd/nscd.h

@@ -195,4 +195,8 @@ extern void readdhstbyaddrv6 (struct database_dyn *db, struct hashentry *he,
 extern void *mempool_alloc (struct database_dyn *db, size_t len);
 extern void gc (struct database_dyn *db);
 
+
+/* nscd_setup_thread.c */
+extern void setup_thread (struct database_dyn *db);
+
 #endif /* nscd.h */

nscd/nscd_helper.c

@@ -234,11 +234,8 @@ __nscd_get_map_ref (request_type type, const char *name,
     {
       /* If not mapped or timestamp not updated, request new map.  */
       if (cur == NULL
-	  // XXX The following syscalls increases the cost of the entire
+	  || (cur->head->nscd_certainly_running == 0
-	  // XXX lookup by a factor of 5 but unfortunately there is not
+	      && cur->head->timestamp + MAPPING_TIMEOUT < time (NULL)))
-	  // XXX much we can do except hoping we get a userlevel
-	  // XXX implementation soon.
-	  || cur->head->timestamp + MAPPING_TIMEOUT < time (NULL))
 	cur = get_mapping (type, name, &mapptr->mapped);
 
       if (__builtin_expect (cur != NO_MAPPING, 1))

sysdeps/generic/nscd_setup_thread.c

@@ -0,0 +1,28 @@
+/* Setup of nscd worker threads.  Stub verison.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <nscd.h>
+
+
+void
+setup_thread (struct database_dyn *db)
+{
+  /* Nothing.  */
+}

sysdeps/unix/sysv/linux/nscd_setup_thread.c

@@ -0,0 +1,47 @@
+/* Setup of nscd worker threads.  Linux verison.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <string.h>
+#include <unistd.h>
+#include <nscd.h>
+#include <sysdep.h>
+
+
+void
+setup_thread (struct database_dyn *db)
+{
+  /* Only supported when NPTL is used.  */
+  char buf[100];
+  if (confstr (_CS_GNU_LIBPTHREAD_VERSION, buf, sizeof (buf)) >= sizeof (buf)
+      || strncmp (buf, "NPTL", 4) != 0)
+    return;
+
+  /* Do not try this at home, kids.  We play with the SETTID address
+     even thought the process is multi-threaded.  This can only work
+     since none of the threads ever terminates.  */
+  INTERNAL_SYSCALL_DECL (err);
+  int r = INTERNAL_SYSCALL (set_tid_address, err, 1,
+			    &db->head->nscd_certainly_running);
+  if (!INTERNAL_SYSCALL_ERROR_P (r, err))
+    /* We know the kernel can reset this field when nscd terminates.
+       So, set the field to a nonzero value which indicates that nscd
+       is certainly running and clients can skip the test.  */
+    db->head->nscd_certainly_running = 1;
+}