diff options
| -rw-r--r-- | nscd/connections.c | 222 |
1 files changed, 122 insertions, 100 deletions
diff --git a/nscd/connections.c b/nscd/connections.c index 3628877..c80ba96 100644 --- a/nscd/connections.c +++ b/nscd/connections.c @@ -19,6 +19,7 @@ 02111-1307 USA. */ #include <assert.h> +#include <atomic.h> #include <error.h> #include <errno.h> #include <grp.h> @@ -130,6 +131,9 @@ int nthreads = -1; /* Socket for incoming connections. */ static int sock; +/* Number of times clients had to wait. */ +unsigned long int client_queued; + /* Initialize database information structures. */ void @@ -435,145 +439,163 @@ nscd_run (void *p) long int my_number = (long int) p; struct pollfd conn; int run_prune = my_number < lastdb && dbs[my_number].enabled; - time_t now = time (NULL); - time_t next_prune = now + CACHE_PRUNE_INTERVAL; - int timeout = run_prune ? 1000 * (next_prune - now) : -1; + time_t next_prune = run_prune ? time (NULL) + CACHE_PRUNE_INTERVAL : 0; + static unsigned long int nready; conn.fd = sock; conn.events = POLLRDNORM; while (1) { - int nr = poll (&conn, 1, timeout); + int nr; + + /* One more thread available. */ + atomic_increment (&nready); + + no_conn: + if (run_prune) + do + { + time_t now = time (NULL); + int timeout = now < next_prune ? 1000 * (next_prune - now) : 0; + + nr = poll (&conn, 1, timeout); + + if (nr == 0) + { + /* The `poll' call timed out. It's time to clean up the + cache. */ + atomic_decrement (&nready); + assert (my_number < lastdb); + prune_cache (&dbs[my_number], time(NULL)); + now = time (NULL); + next_prune = now + CACHE_PRUNE_INTERVAL; + goto try_get; + } + } + while ((conn.revents & POLLRDNORM) == 0); + + got_data:; + /* We have a new incoming connection. Accept the connection. */ + int fd = TEMP_FAILURE_RETRY (accept (conn.fd, NULL, NULL)); + request_header req; + char buf[256]; + uid_t uid = 0; +#ifdef SO_PEERCRED + pid_t pid = 0; +#endif - if (nr == 0) + if (__builtin_expect (fd, 0) < 0) { - /* The `poll' call timed out. It's time to clean up the cache. */ - assert (my_number < lastdb); - now = time (NULL); - prune_cache (&dbs[my_number], now); - next_prune = now + CACHE_PRUNE_INTERVAL; - timeout = 1000 * (next_prune - now); - continue; + dbg_log (_("while accepting connection: %s"), + strerror_r (errno, buf, sizeof (buf))); + goto no_conn; } - /* We have a new incoming connection. */ - if (conn.revents & (POLLRDNORM|POLLERR|POLLHUP|POLLNVAL)) + /* This thread is busy. */ + atomic_decrement (&nready); + + /* Now read the request. */ + if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req))) + != sizeof (req), 0)) { - /* Accept the connection. */ - int fd = TEMP_FAILURE_RETRY (accept (conn.fd, NULL, NULL)); - request_header req; - char buf[256]; - uid_t uid = 0; + if (debug_level > 0) + dbg_log (_("short read while reading request: %s"), + strerror_r (errno, buf, sizeof (buf))); + close (fd); + continue; + } + + /* Some systems have no SO_PEERCRED implementation. They don't + care about security so we don't as well. */ #ifdef SO_PEERCRED - pid_t pid = 0; -#endif + if (secure_in_use) + { + struct ucred caller; + socklen_t optlen = sizeof (caller); - if (__builtin_expect (fd, 0) < 0) + if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) < 0) { - dbg_log (_("while accepting connection: %s"), + dbg_log (_("error getting callers id: %s"), strerror_r (errno, buf, sizeof (buf))); - continue; - } - - /* Now read the request. */ - if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, - sizeof (req))) - != sizeof (req), 0)) - { - if (debug_level > 0) - dbg_log (_("short read while reading request: %s"), - strerror_r (errno, buf, sizeof (buf))); close (fd); continue; } - /* Some systems have no SO_PEERCRED implementation. They don't - care about security so we don't as well. */ -#ifdef SO_PEERCRED - if (secure_in_use) - { - struct ucred caller; - socklen_t optlen = sizeof (caller); - - if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, - &caller, &optlen) < 0) - { - dbg_log (_("error getting callers id: %s"), - strerror_r (errno, buf, sizeof (buf))); - close (fd); - continue; - } - - if (req.type < GETPWBYNAME || req.type > LASTDBREQ - || secure[serv2db[req.type]]) - uid = caller.uid; + if (req.type < GETPWBYNAME || req.type > LASTDBREQ + || secure[serv2db[req.type]]) + uid = caller.uid; pid = caller.pid; - } - else if (__builtin_expect (debug_level > 0, 0)) - { - struct ucred caller; - socklen_t optlen = sizeof (caller); + } + else if (__builtin_expect (debug_level > 0, 0)) + { + struct ucred caller; + socklen_t optlen = sizeof (caller); - if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, - &caller, &optlen) == 0) - pid = caller.pid; - } + if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &caller, &optlen) == 0) + pid = caller.pid; + } #endif - /* It should not be possible to crash the nscd with a silly - request (i.e., a terribly large key). We limit the size - to 1kb. */ - if (__builtin_expect (req.key_len, 1) < 0 - || __builtin_expect (req.key_len, 1) > 1024) + /* It should not be possible to crash the nscd with a silly + request (i.e., a terribly large key). We limit the size to 1kb. */ + if (__builtin_expect (req.key_len, 1) < 0 + || __builtin_expect (req.key_len, 1) > 1024) + { + if (debug_level > 0) + dbg_log (_("key length in request too long: %d"), req.key_len); + close (fd); + continue; + } + else + { + /* Get the key. */ + char keybuf[req.key_len]; + + if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf, + req.key_len)) + != req.key_len, 0)) { if (debug_level > 0) - dbg_log (_("key length in request too long: %d"), req.key_len); + dbg_log (_("short read while reading request key: %s"), + strerror_r (errno, buf, sizeof (buf))); close (fd); continue; } - else + + if (__builtin_expect (debug_level, 0) > 0) { - /* Get the key. */ - char keybuf[req.key_len]; - - if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, keybuf, - req.key_len)) - != req.key_len, 0)) - { - if (debug_level > 0) - dbg_log (_("short read while reading request key: %s"), - strerror_r (errno, buf, sizeof (buf))); - close (fd); - continue; - } - - if (__builtin_expect (debug_level, 0) > 0) - { #ifdef SO_PEERCRED - if (pid != 0) - dbg_log (_("\ + if (pid != 0) + dbg_log (_("\ handle_request: request received (Version = %d) from PID %ld"), - req.version, (long int) pid); - else + req.version, (long int) pid); + else #endif - dbg_log (_("\ + dbg_log (_("\ handle_request: request received (Version = %d)"), req.version); - } + } - /* Phew, we got all the data, now process it. */ - handle_request (fd, &req, keybuf, uid); + /* Phew, we got all the data, now process it. */ + handle_request (fd, &req, keybuf, uid); - /* We are done. */ - close (fd); - } + /* We are done. */ + close (fd); } - if (run_prune) + /* Just determine whether any data is present. We do this to + measure whether clients are queued up. */ + try_get: + nr = poll (&conn, 1, 0); + if (nr != 0) { - now = time (NULL); - timeout = now < next_prune ? 1000 * (next_prune - now) : 0; + if (nready == 0) + ++client_queued; + + atomic_increment (&nready); + + goto got_data; } } } |