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Update,
* nscd/connections.c: Rewrite handling of incoming connections. All are handled by one thread which then hands of the descriptors for the real work to the worker threads. * nscd/Makefile: Link nscd with librt. * nscd/selinux.c: Pretty printing. * nscd/dbg_log.c (dbg_log): Don't add unnecessary newline to output. Let syslog do the formatting if debug_level == 0.
This commit is contained in:
Ulrich Drepper
parent
1507c81f2a
commit
1945c96f2b
10
ChangeLog
10
ChangeLog
@ -1,5 +1,15 @@
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2004-10-02 Ulrich Drepper <drepper@redhat.com>
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* nscd/connections.c: Rewrite handling of incoming connections. All
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are handled by one thread which then hands of the descriptors for the
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real work to the worker threads.
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* nscd/Makefile: Link nscd with librt.
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* nscd/selinux.c: Pretty printing.
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* nscd/dbg_log.c (dbg_log): Don't add unnecessary newline to
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output. Let syslog do the formatting if debug_level == 0.
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* nscd/nscd_helper.c (get_mapping): No need to check timestamp if
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nscd_certainly_running is nonzero.
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@ -112,9 +112,11 @@ $(objpfx)nscd: $(nscd-modules:%=$(objpfx)%.o)
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$(objpfx)nscd_nischeck: $(objpfx)nscd_nischeck.o
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ifeq ($(build-shared),yes)
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$(objpfx)nscd: $(shared-thread-library) $(common-objpfx)nis/libnsl.so
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$(objpfx)nscd: $(common-objpfx)rt/librt.so $(shared-thread-library) \
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$(common-objpfx)nis/libnsl.so
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$(objpfx)nscd_nischeck: $(common-objpfx)nis/libnsl.so
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else
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$(objpfx)nscd: $(static-thread-library) $(common-objpfx)nis/libnsl.a
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$(objpfx)nscd: $(common-objpfx)rt/librt.a $(static-thread-library) \
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$(common-objpfx)nis/libnsl.a
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$(objpfx)nscd_nischeck: $(common-objpfx)nis/libnsl.a
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endif
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@ -785,91 +785,120 @@ cannot handle old request version %d; current version is %d"),
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}
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/* List of file descriptors. */
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struct fdlist
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{
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int fd;
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struct fdlist *next;
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};
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/* Memory allocated for the list. */
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static struct fdlist *fdlist;
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/* List of currently ready-to-read file descriptors. */
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static struct fdlist *readylist;
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/* Conditional variable and mutex to signal availability of entries in
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READYLIST. The condvar is initialized dynamically since we might
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use a different clock depending on availability. */
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static pthread_cond_t readylist_cond;
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static pthread_mutex_t readylist_lock = PTHREAD_MUTEX_INITIALIZER;
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/* The clock to use with the condvar. */
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static clockid_t timeout_clock = CLOCK_REALTIME;
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/* Number of threads ready to handle the READYLIST. */
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static unsigned long int nready;
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/* This is the main loop. It is replicated in different threads but the
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`poll' call makes sure only one thread handles an incoming connection. */
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static void *
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__attribute__ ((__noreturn__))
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nscd_run (void *p)
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{
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long int my_number = (long int) p;
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struct pollfd conn;
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int run_prune = my_number < lastdb && dbs[my_number].enabled;
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time_t next_prune = run_prune ? time (NULL) + CACHE_PRUNE_INTERVAL : 0;
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static unsigned long int nready;
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const long int my_number = (long int) p;
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const int run_prune = my_number < lastdb && dbs[my_number].enabled;
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struct timespec prune_ts;
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int to = 0;
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char buf[256];
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if (run_prune)
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setup_thread (&dbs[my_number]);
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{
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setup_thread (&dbs[my_number]);
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conn.fd = sock;
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conn.events = POLLRDNORM;
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/* We are running. */
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dbs[my_number].head->timestamp = time (NULL);
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if (clock_gettime (timeout_clock, &prune_ts) == -1)
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/* Should never happen. */
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abort ();
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/* Compute timeout time. */
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prune_ts.tv_sec += CACHE_PRUNE_INTERVAL;
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}
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/* Initial locking. */
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pthread_mutex_lock (&readylist_lock);
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/* One more thread available. */
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++nready;
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while (1)
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{
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int nr;
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time_t now = 0;
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/* One more thread available. */
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atomic_increment (&nready);
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no_conn:
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do
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while (readylist == NULL)
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{
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int timeout = -1;
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if (run_prune)
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{
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/* NB: we do not flush the timestamp update using msync since
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this value doesnot matter on disk. */
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dbs[my_number].head->timestamp = now = time (NULL);
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timeout = now < next_prune ? 1000 * (next_prune - now) : 0;
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/* Wait, but not forever. */
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to = pthread_cond_timedwait (&readylist_cond, &readylist_lock,
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&prune_ts);
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/* If we were woken and there is no work to be done,
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just start pruning. */
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if (readylist == NULL && to == ETIMEDOUT)
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{
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pthread_mutex_unlock (&readylist_lock);
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goto only_prune;
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}
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}
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nr = poll (&conn, 1, timeout);
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if (nr == 0)
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{
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/* The `poll' call timed out. It's time to clean up the
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cache. */
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atomic_decrement (&nready);
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assert (my_number < lastdb);
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prune_cache (&dbs[my_number], time(NULL));
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now = time (NULL);
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next_prune = now + CACHE_PRUNE_INTERVAL;
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goto try_get;
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}
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}
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while ((conn.revents & POLLRDNORM) == 0);
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got_data:;
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/* We have a new incoming connection. Accept the connection. */
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int fd = TEMP_FAILURE_RETRY (accept (conn.fd, NULL, NULL));
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request_header req;
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char buf[256];
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uid_t uid = -1;
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#ifdef SO_PEERCRED
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pid_t pid = 0;
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#endif
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if (__builtin_expect (fd, 0) < 0)
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{
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if (errno != EAGAIN && errno != EWOULDBLOCK)
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dbg_log (_("while accepting connection: %s"),
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strerror_r (errno, buf, sizeof (buf)));
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goto no_conn;
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else
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/* No need to timeout. */
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pthread_cond_wait (&readylist_cond, &readylist_lock);
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}
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/* This thread is busy. */
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atomic_decrement (&nready);
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struct fdlist *it = readylist->next;
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if (readylist->next == readylist)
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/* Just one entry on the list. */
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readylist = NULL;
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else
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readylist->next = it->next;
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/* Extract the information and mark the record ready to be used
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again. */
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int fd = it->fd;
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it->next = NULL;
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/* One more thread available. */
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--nready;
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/* We are done with the list. */
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pthread_mutex_unlock (&readylist_lock);
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/* We do not want to block on a short read or so. */
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int fl = fcntl (fd, F_GETFL);
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if (fl == -1 || fcntl (fd, F_SETFL, fl | O_NONBLOCK) == -1)
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goto close_and_out;
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/* Now read the request. */
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request_header req;
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if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req)))
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!= sizeof (req), 0))
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{
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/* We failed to read data. Note that this also might mean we
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failed because we would have blocked. */
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if (debug_level > 0)
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dbg_log (_("short read while reading request: %s"),
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strerror_r (errno, buf, sizeof (buf)));
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close (fd);
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continue;
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goto close_and_out;
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}
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/* Check whether this is a valid request type. */
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@ -878,7 +907,10 @@ nscd_run (void *p)
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/* Some systems have no SO_PEERCRED implementation. They don't
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care about security so we don't as well. */
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uid_t uid = -1;
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#ifdef SO_PEERCRED
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pid_t pid = 0;
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if (secure_in_use)
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{
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struct ucred caller;
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@ -909,8 +941,9 @@ nscd_run (void *p)
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/* It should not be possible to crash the nscd with a silly
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request (i.e., a terribly large key). We limit the size to 1kb. */
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#define MAXKEYLEN 1024
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if (__builtin_expect (req.key_len, 1) < 0
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|| __builtin_expect (req.key_len, 1) > 1024)
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|| __builtin_expect (req.key_len, 1) > MAXKEYLEN)
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{
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if (debug_level > 0)
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dbg_log (_("key length in request too long: %d"), req.key_len);
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@ -918,17 +951,17 @@ nscd_run (void *p)
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else
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{
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/* Get the key. */
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char keybuf[req.key_len];
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char keybuf[MAXKEYLEN];
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if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf,
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req.key_len))
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!= req.key_len, 0))
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{
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/* Again, this can also mean we would have blocked. */
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if (debug_level > 0)
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dbg_log (_("short read while reading request key: %s"),
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strerror_r (errno, buf, sizeof (buf)));
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close (fd);
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continue;
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goto close_and_out;
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}
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if (__builtin_expect (debug_level, 0) > 0)
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@ -952,18 +985,193 @@ handle_request: request received (Version = %d)"), req.version);
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/* We are done. */
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close (fd);
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/* Just determine whether any data is present. We do this to
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measure whether clients are queued up. */
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try_get:
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nr = poll (&conn, 1, 0);
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if (nr != 0)
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/* Check whether we should be pruning the cache. */
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assert (run_prune || to == 0);
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if (to == ETIMEDOUT)
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{
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if (nready == 0)
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++client_queued;
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only_prune:
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/* The pthread_cond_timedwait() call timed out. It is time
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to clean up the cache. */
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assert (my_number < lastdb);
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prune_cache (&dbs[my_number],
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prune_ts.tv_sec + (prune_ts.tv_nsec >= 500000000));
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atomic_increment (&nready);
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if (clock_gettime (timeout_clock, &prune_ts) == -1)
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/* Should never happen. */
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abort ();
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goto got_data;
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/* Compute next timeout time. */
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prune_ts.tv_sec += CACHE_PRUNE_INTERVAL;
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/* In case the list is emtpy we do not want to run the prune
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code right away again. */
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to = 0;
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}
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/* Re-locking. */
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pthread_mutex_lock (&readylist_lock);
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/* One more thread available. */
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++nready;
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}
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}
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static void
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__attribute__ ((__noreturn__))
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main_loop (void)
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{
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/* Determine how much room for descriptors we should initially
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allocate. This might need to change later if we cap the number
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with MAXCONN. */
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const long int nfds = sysconf (_SC_OPEN_MAX);
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unsigned int nconns;
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#define MINCONN 32
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#define MAXCONN 16384
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if (nfds == -1 || nfds > MAXCONN)
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nconns = MAXCONN;
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else if (nfds < MINCONN)
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nconns = MINCONN;
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else
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nconns = nfds;
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struct pollfd *conns = (struct pollfd *) xmalloc (nconns
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* sizeof (conns[0]));
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/* We need two mirroring arrays filled with the times the connection
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was accepted and a place to pass descriptors on to the worker
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threads. We cannot put this in the same data structure as the
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CONNS data since CONNS is passed as an array to poll(). */
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time_t *starttime = (time_t *) xmalloc (nconns * sizeof (starttime[0]));
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fdlist = (struct fdlist *) xcalloc (nconns, sizeof (fdlist[0]));
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conns[0].fd = sock;
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conns[0].events = POLLRDNORM;
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size_t nused = 1;
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size_t firstfree = 1;
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|
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while (1)
|
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{
|
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/* Wait for any event. We wait at most a couple of seconds so
|
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that we can check whether we should close any of the accepted
|
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connections since we have not received a request. */
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#define MAX_ACCEPT_TIMEOUT 30
|
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#define MIN_ACCEPT_TIMEOUT 5
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#define MAIN_THREAD_TIMEOUT \
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(MAX_ACCEPT_TIMEOUT * 1000 \
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- ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * 1000 * nused) / (2 * nconns))
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|
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int n = poll (conns, nused, MAIN_THREAD_TIMEOUT);
|
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|
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time_t now = time (NULL);
|
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|
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/* If there is a descriptor ready for reading or there is a new
|
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connection, process this now. */
|
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if (n > 0)
|
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{
|
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if (conns[0].revents != 0)
|
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{
|
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/* We have a new incoming connection. Accept the connection. */
|
||||
int fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL));
|
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|
||||
if (fd >= 0)
|
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{
|
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/* We have a new file descriptor. Keep it around
|
||||
and wait until data becomes available. */
|
||||
if (firstfree == nconns)
|
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{
|
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// XXX Maybe extend array. For now, reject
|
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close (fd);
|
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goto reject_out;
|
||||
}
|
||||
|
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conns[firstfree].fd = fd;
|
||||
conns[firstfree].events = POLLRDNORM;
|
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starttime[firstfree] = now;
|
||||
if (firstfree >= nused)
|
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nused = firstfree + 1;
|
||||
|
||||
do
|
||||
++firstfree;
|
||||
while (firstfree < nused && conns[firstfree].fd != -1);
|
||||
}
|
||||
|
||||
reject_out:
|
||||
--n;
|
||||
}
|
||||
|
||||
for (size_t cnt = 1; cnt < nused && n > 0; ++cnt)
|
||||
if (conns[cnt].revents != 0)
|
||||
{
|
||||
pthread_mutex_lock (&readylist_lock);
|
||||
|
||||
/* Find an empty entry in FDLIST. */
|
||||
size_t inner;
|
||||
for (inner = 0; inner < nconns; ++inner)
|
||||
if (fdlist[inner].next == NULL)
|
||||
break;
|
||||
assert (inner < nconns);
|
||||
|
||||
fdlist[inner].fd = conns[cnt].fd;
|
||||
|
||||
if (readylist == NULL)
|
||||
readylist = fdlist[inner].next = &fdlist[inner];
|
||||
else
|
||||
{
|
||||
fdlist[inner].next = readylist->next;
|
||||
readylist = readylist->next = &fdlist[inner];
|
||||
}
|
||||
|
||||
bool do_signal = true;
|
||||
if (__builtin_expect (nready == 0, 0))
|
||||
{
|
||||
++client_queued;
|
||||
do_signal = false;
|
||||
}
|
||||
|
||||
pthread_mutex_unlock (&readylist_lock);
|
||||
|
||||
/* Tell one of the worker threads there is work to do. */
|
||||
if (do_signal)
|
||||
pthread_cond_signal (&readylist_cond);
|
||||
|
||||
/* Clean up the CONNS array. */
|
||||
conns[cnt].fd = -1;
|
||||
if (cnt < firstfree)
|
||||
firstfree = cnt;
|
||||
if (cnt == nused - 1)
|
||||
do
|
||||
--nused;
|
||||
while (conns[nused - 1].fd == -1);
|
||||
|
||||
--n;
|
||||
}
|
||||
}
|
||||
|
||||
/* Now find entries which have timed out. */
|
||||
assert (nused > 0);
|
||||
for (size_t cnt = nused - 1; cnt > 0; --cnt)
|
||||
{
|
||||
/* We make the timeout length depend on the number of file
|
||||
descriptors currently used. */
|
||||
#define ACCEPT_TIMEOUT \
|
||||
(MAX_ACCEPT_TIMEOUT \
|
||||
- ((MAX_ACCEPT_TIMEOUT - MIN_ACCEPT_TIMEOUT) * nused) / nconns)
|
||||
|
||||
time_t laststart = now - ACCEPT_TIMEOUT;
|
||||
if (conns[cnt].fd != -1 && starttime[cnt] < laststart)
|
||||
{
|
||||
/* Remove the entry, it timed out. */
|
||||
(void) close (conns[cnt].fd);
|
||||
conns[cnt].fd = -1;
|
||||
|
||||
if (cnt < firstfree)
|
||||
firstfree = cnt;
|
||||
if (cnt == nused - 1)
|
||||
do
|
||||
--nused;
|
||||
while (conns[nused - 1].fd == -1);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -973,10 +1181,26 @@ handle_request: request received (Version = %d)"), req.version);
|
||||
void
|
||||
start_threads (void)
|
||||
{
|
||||
long int i;
|
||||
pthread_attr_t attr;
|
||||
pthread_t th;
|
||||
/* Initialize the conditional variable we will use. The only
|
||||
non-standard attribute we might use is the clock selection. */
|
||||
pthread_condattr_t condattr;
|
||||
pthread_condattr_init (&condattr);
|
||||
|
||||
#if _POSIX_CLOCK_SELECTION >= 0 && _POSIX_MONOTONIC_CLOCK >= 0
|
||||
/* Determine whether the monotonous clock is available. */
|
||||
struct timespec dummy;
|
||||
if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0
|
||||
&& pthread_condattr_setclock (&condattr, CLOCK_MONOTONIC) == 0)
|
||||
timeout_clock = CLOCK_MONOTONIC;
|
||||
#endif
|
||||
|
||||
pthread_cond_init (&readylist_cond, &condattr);
|
||||
pthread_condattr_destroy (&condattr);
|
||||
|
||||
|
||||
/* Create the attribute for the threads. They are all created
|
||||
detached. */
|
||||
pthread_attr_t attr;
|
||||
pthread_attr_init (&attr);
|
||||
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
|
||||
|
||||
@ -984,12 +1208,17 @@ start_threads (void)
|
||||
if (debug_level == 0)
|
||||
nthreads = MAX (nthreads, lastdb);
|
||||
|
||||
for (i = 1; i < nthreads; ++i)
|
||||
pthread_create (&th, &attr, nscd_run, (void *) i);
|
||||
for (long int i = 0; i < nthreads; ++i)
|
||||
{
|
||||
pthread_t th;
|
||||
pthread_create (&th, &attr, nscd_run, (void *) i);
|
||||
}
|
||||
|
||||
pthread_attr_destroy (&attr);
|
||||
|
||||
nscd_run ((void *) 0);
|
||||
/* In the main thread we execute the loop which handles incoming
|
||||
connections. */
|
||||
main_loop ();
|
||||
}
|
||||
|
||||
|
||||
|
||||
@ -61,7 +61,8 @@ dbg_log (const char *fmt,...)
|
||||
|
||||
if (debug_level > 0)
|
||||
{
|
||||
snprintf (msg, sizeof (msg), "%d: %s\n", getpid (), msg2);
|
||||
snprintf (msg, sizeof (msg), "%d: %s%s", getpid (), msg2,
|
||||
msg2[strlen (msg2) - 1] == '\n' ? "" : "\n");
|
||||
if (dbgout)
|
||||
{
|
||||
fputs (msg, dbgout);
|
||||
@ -71,9 +72,7 @@ dbg_log (const char *fmt,...)
|
||||
fputs (msg, stderr);
|
||||
}
|
||||
else
|
||||
{
|
||||
snprintf (msg, sizeof (msg), "%d: %s", getpid (), msg2);
|
||||
syslog (LOG_NOTICE, "%s", msg);
|
||||
}
|
||||
syslog (LOG_NOTICE, "%d %s", getpid (), msg2);
|
||||
|
||||
va_end (ap);
|
||||
}
|
||||
|
||||
@ -207,8 +207,8 @@ nscd_request_avc_has_perm (int fd, request_type req)
|
||||
dbg_log (_("Error getting context of nscd"));
|
||||
goto out;
|
||||
}
|
||||
if (avc_context_to_sid (scon, &ssid) < 0 ||
|
||||
avc_context_to_sid (tcon, &tsid) < 0)
|
||||
if (avc_context_to_sid (scon, &ssid) < 0
|
||||
|| avc_context_to_sid (tcon, &tsid) < 0)
|
||||
{
|
||||
dbg_log (_("Error getting sid from context"));
|
||||
goto out;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user