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>
This commit is contained in:
Ulrich Drepper 2004-09-08 17:56:46 +00:00
parent c207f23b0b
commit 081fc592fa
8 changed files with 99 additions and 6 deletions

View File

@ -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

View File

@ -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)

View File

@ -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;

View File

@ -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;

View File

@ -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 */

View File

@ -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
// XXX lookup by a factor of 5 but unfortunately there is not
// XXX much we can do except hoping we get a userlevel
// XXX implementation soon.
|| cur->head->timestamp + MAPPING_TIMEOUT < time (NULL))
|| (cur->head->nscd_certainly_running == 0
&& cur->head->timestamp + MAPPING_TIMEOUT < time (NULL)))
cur = get_mapping (type, name, &mapptr->mapped);
if (__builtin_expect (cur != NO_MAPPING, 1))

View File

@ -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. */
}

View File

@ -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;
}