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authorUlrich Drepper <drepper@redhat.com>2008-06-12 22:40:27 +0000
committerUlrich Drepper <drepper@redhat.com>2008-06-12 22:40:27 +0000
commit5228ba2fe881133ccc0f9b3ad8a1ebbe9112a6f2 (patch)
tree226b31672d444eaf3ad88b7ee96bbf55d660b8dd /nscd
parent5a337776da5b7ff1dbbf0fdcd093a3b6af2cdf83 (diff)
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* nscd/nscd.h (struct database_dyn): Add inotify_descr and clear_cache
fields. * nscd/connections.c (inotify_fd): New variable. (nscd_init): Try to open an inotify descriptor. If successful, watch files for databases using inotify instead of having prune threads stat the files. (nscd_run_prune): Recognize clear_cache flag being set and call prune_cache appropriately. (main_loop_poll): Add inotify descriptor to wait set and handle the reported changes. (main_loop_epoll): Likewise. * nscd/cache.c (prune_cache): Don't stat files for databases if inotify is used. * sysdeps/unix/sysv/linux/Makefile [subdir=nscd] (CFLAGS-connections.c): Add -DHAVE_INOTIFY.
Diffstat (limited to 'nscd')
-rw-r--r--nscd/cache.c2
-rw-r--r--nscd/connections.c143
-rw-r--r--nscd/nscd.h2
3 files changed, 132 insertions, 15 deletions
diff --git a/nscd/cache.c b/nscd/cache.c
index 2faaf34..cd6e6b4 100644
--- a/nscd/cache.c
+++ b/nscd/cache.c
@@ -274,7 +274,7 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
/* If we check for the modification of the underlying file we invalidate
the entries also in this case. */
- if (table->check_file && now != LONG_MAX)
+ if (table->inotify_descr < 0 && table->check_file && now != LONG_MAX)
{
struct stat64 st;
diff --git a/nscd/connections.c b/nscd/connections.c
index e6a2c94..bef1c16 100644
--- a/nscd/connections.c
+++ b/nscd/connections.c
@@ -35,6 +35,9 @@
#ifdef HAVE_EPOLL
# include <sys/epoll.h>
#endif
+#ifdef HAVE_INOTIFY
+# include <sys/inotify.h>
+#endif
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/poll.h>
@@ -222,6 +225,11 @@ int max_nthreads = 32;
/* Socket for incoming connections. */
static int sock;
+#ifdef HAVE_INOTIFY
+/* Inotify descriptor. */
+static int inotify_fd = -1;
+#endif
+
/* Number of times clients had to wait. */
unsigned long int client_queued;
@@ -503,6 +511,13 @@ nscd_init (void)
/* No configuration for this value, assume a default. */
nthreads = 4;
+#ifdef HAVE_INOTIFY
+ /* Use inotify to recognize changed files. */
+ inotify_fd = inotify_init ();
+ if (inotify_fd != -1)
+ fcntl (inotify_fd, F_SETFL, O_NONBLOCK);
+#endif
+
for (size_t cnt = 0; cnt < lastdb; ++cnt)
if (dbs[cnt].enabled)
{
@@ -805,20 +820,30 @@ cannot set socket to close on exec: %s; disabling paranoia mode"),
assert (dbs[cnt].ro_fd == -1);
}
+ dbs[cnt].inotify_descr = -1;
if (dbs[cnt].check_file)
{
- /* We need the modification date of the file. */
- struct stat64 st;
-
- if (stat64 (dbs[cnt].filename, &st) < 0)
+#ifdef HAVE_INOTIFY
+ if (inotify_fd == -1
+ || (dbs[cnt].inotify_descr
+ = inotify_add_watch (inotify_fd, dbs[cnt].filename,
+ IN_DELETE_SELF | IN_MODIFY)) < 0)
+ /* We cannot notice changes in the main thread. */
+#endif
{
- /* We cannot stat() the file, disable file checking. */
- dbg_log (_("cannot stat() file `%s': %s"),
- dbs[cnt].filename, strerror (errno));
- dbs[cnt].check_file = 0;
+ /* We need the modification date of the file. */
+ struct stat64 st;
+
+ if (stat64 (dbs[cnt].filename, &st) < 0)
+ {
+ /* We cannot stat() the file, disable file checking. */
+ dbg_log (_("cannot stat() file `%s': %s"),
+ dbs[cnt].filename, strerror (errno));
+ dbs[cnt].check_file = 0;
+ }
+ else
+ dbs[cnt].file_mtime = st.st_mtime;
}
- else
- dbs[cnt].file_mtime = st.st_mtime;
}
}
@@ -1428,12 +1453,15 @@ nscd_run_prune (void *p)
while (1)
{
/* Wait, but not forever. */
- int e = pthread_cond_timedwait (prune_cond, prune_lock, &prune_ts);
+ int e = 0;
+ if (! dbs[my_number].clear_cache)
+ e = pthread_cond_timedwait (prune_cond, prune_lock, &prune_ts);
assert (__builtin_expect (e == 0 || e == ETIMEDOUT, 1));
time_t next_wait;
now = time (NULL);
- if (e == ETIMEDOUT || now >= dbs[my_number].wakeup_time)
+ if (e == ETIMEDOUT || now >= dbs[my_number].wakeup_time
+ || dbs[my_number].clear_cache)
{
/* We will determine the new timout values based on the
cache content. Should there be concurrent additions to
@@ -1446,9 +1474,13 @@ nscd_run_prune (void *p)
else
dbs[my_number].wakeup_time = INT_MAX;
+ /* Unconditionally reset the flag. */
+ time_t prune_now = dbs[my_number].clear_cache ? LONG_MAX : now;
+ dbs[my_number].clear_cache = 0;
+
pthread_mutex_unlock (prune_lock);
- next_wait = prune_cache (&dbs[my_number], now, -1);
+ next_wait = prune_cache (&dbs[my_number], prune_now, -1);
next_wait = MAX (next_wait, CACHE_PRUNE_INTERVAL);
/* If clients cannot determine for sure whether nscd is running
@@ -1703,6 +1735,16 @@ main_loop_poll (void)
size_t nused = 1;
size_t firstfree = 1;
+#ifdef HAVE_INOTIFY
+ if (inotify_fd != -1)
+ {
+ conns[1].fd = inotify_fd;
+ conns[1].events = POLLRDNORM;
+ nused = 2;
+ firstfree = 2;
+ }
+#endif
+
while (1)
{
/* Wait for any event. We wait at most a couple of seconds so
@@ -1750,7 +1792,42 @@ main_loop_poll (void)
--n;
}
- for (size_t cnt = 1; cnt < nused && n > 0; ++cnt)
+ size_t first = 1;
+#ifdef HAVE_INOTIFY
+ if (conns[1].fd == inotify_fd)
+ {
+ if (conns[1].revents != 0)
+ {
+ union
+ {
+ struct inotify_event i;
+ char buf[100];
+ } inev;
+
+ while (TEMP_FAILURE_RETRY (read (inotify_fd, &inev,
+ sizeof (inev)))
+ >= sizeof (struct inotify_event))
+ {
+ /* Check which of the files changed. */
+ for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
+ if (inev.i.wd == dbs[dbcnt].inotify_descr)
+ {
+ pthread_mutex_trylock (&dbs[dbcnt].prune_lock);
+ dbs[dbcnt].clear_cache = 1;
+ pthread_mutex_unlock (&dbs[dbcnt].prune_lock);
+ pthread_cond_signal (&dbs[dbcnt].prune_cond);
+ break;
+ }
+ }
+
+ --n;
+ }
+
+ first = 2;
+ }
+#endif
+
+ for (size_t cnt = first; cnt < nused && n > 0; ++cnt)
if (conns[cnt].revents != 0)
{
fd_ready (conns[cnt].fd);
@@ -1816,6 +1893,18 @@ main_loop_epoll (int efd)
/* We cannot use epoll. */
return;
+#ifdef HAVE_INOTIFY
+ if (inotify_fd != -1)
+ {
+ ev.events = EPOLLRDNORM;
+ ev.data.fd = inotify_fd;
+ if (epoll_ctl (efd, EPOLL_CTL_ADD, inotify_fd, &ev) == -1)
+ /* We cannot use epoll. */
+ return;
+ nused = 2;
+ }
+#endif
+
while (1)
{
struct epoll_event revs[100];
@@ -1852,6 +1941,32 @@ main_loop_epoll (int efd)
}
}
}
+#ifdef HAVE_INOTIFY
+ else if (revs[cnt].data.fd == inotify_fd)
+ {
+ union
+ {
+ struct inotify_event i;
+ char buf[100];
+ } inev;
+
+ while (TEMP_FAILURE_RETRY (read (inotify_fd, &inev,
+ sizeof (inev)))
+ >= sizeof (struct inotify_event))
+ {
+ /* Check which of the files changed. */
+ for (size_t dbcnt = 0; dbcnt < lastdb; ++dbcnt)
+ if (inev.i.wd == dbs[dbcnt].inotify_descr)
+ {
+ pthread_mutex_trylock (&dbs[dbcnt].prune_lock);
+ dbs[dbcnt].clear_cache = 1;
+ pthread_mutex_unlock (&dbs[dbcnt].prune_lock);
+ pthread_cond_signal (&dbs[dbcnt].prune_cond);
+ break;
+ }
+ }
+ }
+#endif
else
{
/* Remove the descriptor from the epoll descriptor. */
diff --git a/nscd/nscd.h b/nscd/nscd.h
index b07256d..5c77dd3 100644
--- a/nscd/nscd.h
+++ b/nscd/nscd.h
@@ -73,6 +73,8 @@ struct database_dyn
int enabled;
int check_file;
+ int inotify_descr;
+ int clear_cache;
int persistent;
int shared;
int propagate;