]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/connection.c
cleanup
[openldap] / servers / slapd / connection.c
index aead5521da9f073c29467d1749de1e109ca95373..eecf90409b9cb09c3cf6ed5179cb9609d6463704 100644 (file)
@@ -1,7 +1,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 1998-2006 The OpenLDAP Foundation.
+ * Copyright 1998-2007 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
 #include "slapi/slapi.h"
 #endif
 
-#ifdef SLAP_MULTI_CONN_ARRAY
-/* for Multiple Connection Arrary (MCA) Support */
-static ldap_pvt_thread_mutex_t* connections_mutex;
-static Connection **connections = NULL;
-
-/* set to the number of processors (round up to a power of 2) */
-#      define NUM_CONNECTION_ARRAY 4
-
-/* partition the array in a modulo manner */
-#      define MCA_conn_array_id(fd)            ((int)(fd)%NUM_CONNECTION_ARRAY)
-#      define MCA_conn_array_element_id(fd)    ((int)(fd)/NUM_CONNECTION_ARRAY)
-#      define MCA_ARRAY_SIZE                   ((int)(MCA_conn_array_element_id(dtblsize) + (MCA_conn_array_id(dtblsize) ? 1 : 0)))
-#      define MCA_conn_check(fd)               (dtblsize > 0 && (fd) >= 0 && (fd) < (MCA_ARRAY_SIZE*NUM_CONNECTION_ARRAY))
-#      define MCA_GET_CONNECTION(fd) (&(connections[MCA_conn_array_id(fd)]) \
-               [MCA_conn_array_element_id(fd)])
-#      define MCA_GET_CONN_MUTEX(fd) (&connections_mutex[MCA_conn_array_id(fd)])
-
-#else
 /* protected by connections_mutex */
 static ldap_pvt_thread_mutex_t connections_mutex;
 static Connection *connections = NULL;
 
-#      define MCA_conn_check(fd)               (dtblsize > 0 && (fd) < dtblsize)
-#      define MCA_GET_CONNECTION(fd) (&connections[s])
-#      define MCA_GET_CONN_MUTEX(fd) (&connections_mutex)
-#endif
-
 static ldap_pvt_thread_mutex_t conn_nextid_mutex;
 static unsigned long conn_nextid = 0;
 
@@ -79,6 +56,7 @@ static const char conn_lost_str[] = "connection lost";
 #define SLAP_C_UNINITIALIZED   0x00    /* MUST BE ZERO (0) */
 #define SLAP_C_UNUSED                  0x01
 #define SLAP_C_USED                            0x02
+#define        SLAP_C_PENDING                  0x03
 
 /* connection state (protected by c_mutex ) */
 #define SLAP_C_INVALID                 0x00    /* MUST BE ZERO (0) */
@@ -134,69 +112,6 @@ static ldap_pvt_thread_start_t connection_operation;
  * Initialize connection management infrastructure.
  */
 int connections_init(void)
-#ifdef SLAP_MULTI_CONN_ARRAY
-{
-       int             i, j;
-       Connection*     conn;
-
-       assert( connections == NULL );
-
-       if( connections != NULL) {
-               Debug( LDAP_DEBUG_ANY, "connections_init: already initialized.\n",
-                       0, 0, 0 );
-               return -1;
-       }
-
-       connections_mutex = (ldap_pvt_thread_mutex_t*) ch_calloc(
-               NUM_CONNECTION_ARRAY, sizeof(ldap_pvt_thread_mutex_t) );
-       if( connections_mutex == NULL ) {
-               Debug( LDAP_DEBUG_ANY, "connections_init: "
-                       "allocation of connection mutexes failed\n", 0, 0, 0 );
-               return -1;
-       }
-
-       connections = (Connection**) ch_calloc(
-               NUM_CONNECTION_ARRAY, sizeof(Connection*));
-       if( connections == NULL ) {
-               Debug( LDAP_DEBUG_ANY, "connections_init: "
-                       "allocation of connection[%d] failed\n", 0, 0, 0 );
-               return -1;
-       }
-
-       for ( i = 0; i < NUM_CONNECTION_ARRAY; i++ ) {
-               ldap_pvt_thread_mutex_init( connections_mutex+i );
-               connections[i] = (Connection*) ch_calloc(
-                       MCA_ARRAY_SIZE, sizeof(Connection) );
-               if( connections[i] == NULL ) {
-                       Debug( LDAP_DEBUG_ANY, "connections_init: "
-                               "allocation (%d*%ld) of connection array[%d] failed\n",
-                               dtblsize, (long) sizeof(Connection), i );
-                       return -1;
-               }
-       }
-
-       /* should check return of every call */
-       ldap_pvt_thread_mutex_init( &conn_nextid_mutex );
-
-       assert( connections[0]->c_struct_state == SLAP_C_UNINITIALIZED );
-       assert( connections[NUM_CONNECTION_ARRAY-1]->c_struct_state ==
-               SLAP_C_UNINITIALIZED );
-
-       for ( i = 0; i < NUM_CONNECTION_ARRAY; i++ ) {
-               conn = connections[i];
-               for ( j = 0; j < MCA_ARRAY_SIZE; j++ ) {
-                       conn[j].c_conn_idx = j;
-               }
-       }
-
-       /*
-        * per entry initialization of the Connection array initialization
-        * will be done by connection_init()
-        */ 
-
-       return 0;
-}
-#else
 {
        int i;
 
@@ -233,57 +148,12 @@ int connections_init(void)
 
        return 0;
 }
-#endif
 
 /*
  * Destroy connection management infrastructure.
  */
 
 int connections_destroy(void)
-#ifdef SLAP_MULTI_CONN_ARRAY
-{
-       int i;
-       ber_socket_t j;
-
-       if( connections == NULL) {
-               Debug( LDAP_DEBUG_ANY, "connections_destroy: nothing to destroy.\n",
-                       0, 0, 0 );
-               return -1;
-       }
-
-    for ( i = 0; i < NUM_CONNECTION_ARRAY; i++ ) {
-               Connection* conn = connections[i];
-               for ( j = 0; j < MCA_ARRAY_SIZE; j++ ) {
-                       if( conn[j].c_struct_state != SLAP_C_UNINITIALIZED ) {
-                               ber_sockbuf_free( conn[j].c_sb );
-                               ldap_pvt_thread_mutex_destroy( &conn[j].c_mutex );
-                               ldap_pvt_thread_mutex_destroy( &conn[j].c_write_mutex );
-                               ldap_pvt_thread_cond_destroy( &conn[j].c_write_cv );
-#ifdef LDAP_SLAPI
-                               if ( slapi_plugins_used ) {
-                                       slapi_int_free_object_extensions( SLAPI_X_EXT_CONNECTION,
-                                               &conn[j] );
-                               }
-#endif
-                       }
-               }
-       }
-
-       for ( i = 0; i < NUM_CONNECTION_ARRAY; i++ ) {
-               free( connections[i] );
-               connections[i] = NULL;
-               ldap_pvt_thread_mutex_destroy( &connections_mutex[i] );
-       }
-
-       free( connections );
-       free( connections_mutex );
-
-       ldap_pvt_thread_mutex_destroy( &conn_nextid_mutex );
-
-       return 0;
-
-}
-#else
 {
        ber_socket_t i;
 
@@ -317,75 +187,35 @@ int connections_destroy(void)
        ldap_pvt_thread_mutex_destroy( &conn_nextid_mutex );
        return 0;
 }
-#endif
 
 /*
  * shutdown all connections
  */
 int connections_shutdown(void)
-#ifdef SLAP_MULTI_CONN_ARRAY
-{
-       int i;
-       ber_socket_t j;
-
-       for ( i = 0; i < NUM_CONNECTION_ARRAY; i++ ) {
-               Connection* conn = connections[i];
-               ldap_pvt_thread_mutex_lock( &connections_mutex[i] );
-               for ( j = 0; j < MCA_ARRAY_SIZE; j++ ) {
-                       if( conn[j].c_struct_state != SLAP_C_USED ) {
-                               continue;
-                       }
-                       /* give persistent clients a chance to cleanup */
-                       if( conn[j].c_conn_state == SLAP_C_CLIENT ) {
-                               ldap_pvt_thread_pool_submit( &connection_pool,
-                               conn[j].c_clientfunc, conn[j].c_clientarg );
-                               continue;
-                       }
-
-                       ldap_pvt_thread_mutex_lock( &conn[j].c_mutex );
-                       /* connections_mutex and c_mutex are locked */
-                       connection_closing( &conn[j], "connection shutdown" );
-                       connection_close( &conn[j] );
-                       ldap_pvt_thread_mutex_unlock( &conn[j].c_mutex );
-               }
-
-               ldap_pvt_thread_mutex_unlock( &connections_mutex[i] );
-       }
-
-       return 0;
-
-}
-#else
 {
        ber_socket_t i;
 
-       ldap_pvt_thread_mutex_lock( &connections_mutex );
-
        for ( i = 0; i < dtblsize; i++ ) {
-               if( connections[i].c_struct_state != SLAP_C_USED ) {
-                       continue;
-               }
-               /* give persistent clients a chance to cleanup */
-               if( connections[i].c_conn_state == SLAP_C_CLIENT ) {
-                       ldap_pvt_thread_pool_submit( &connection_pool,
-                       connections[i].c_clientfunc, connections[i].c_clientarg );
-                       continue;
+               if( connections[i].c_struct_state != SLAP_C_UNINITIALIZED ) {
+                       ldap_pvt_thread_mutex_lock( &connections[i].c_mutex );
+                       if( connections[i].c_struct_state == SLAP_C_USED ) {
+
+                               /* give persistent clients a chance to cleanup */
+                               if( connections[i].c_conn_state == SLAP_C_CLIENT ) {
+                                       ldap_pvt_thread_pool_submit( &connection_pool,
+                                       connections[i].c_clientfunc, connections[i].c_clientarg );
+                               } else {
+                                       /* c_mutex is locked */
+                                       connection_closing( &connections[i], "slapd shutdown" );
+                                       connection_close( &connections[i] );
+                               }
+                       }
+                       ldap_pvt_thread_mutex_unlock( &connections[i].c_mutex );
                }
-
-               ldap_pvt_thread_mutex_lock( &connections[i].c_mutex );
-
-               /* connections_mutex and c_mutex are locked */
-               connection_closing( &connections[i], "slapd shutdown" );
-               connection_close( &connections[i] );
-
-               ldap_pvt_thread_mutex_unlock( &connections[i].c_mutex );
        }
 
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
-
        return 0;
 }
-#endif
 
 /*
  * Timeout idle connections.
@@ -420,8 +250,6 @@ int connections_timeout_idle(time_t now)
 
 static Connection* connection_get( ber_socket_t s )
 {
-       /* connections_mutex should be locked by caller */
-
        Connection *c;
 
        Debug( LDAP_DEBUG_ARGS,
@@ -433,15 +261,19 @@ static Connection* connection_get( ber_socket_t s )
        if(s == AC_SOCKET_INVALID) return NULL;
 
 #ifndef HAVE_WINSOCK
-       assert( MCA_conn_check( s ) );
-       c = MCA_GET_CONNECTION(s);
+       assert( s < dtblsize );
+       c = &connections[s];
 
 #else
        c = NULL;
        {
                ber_socket_t i, sd;
 
+               ldap_pvt_thread_mutex_lock( &connections_mutex );
                for(i=0; i<dtblsize; i++) {
+                       if( connections[i].c_struct_state == SLAP_C_PENDING )
+                               continue;
+
                        if( connections[i].c_struct_state == SLAP_C_UNINITIALIZED ) {
                                assert( connections[i].c_conn_state == SLAP_C_INVALID );
                                assert( connections[i].c_sb == 0 );
@@ -466,17 +298,27 @@ static Connection* connection_get( ber_socket_t s )
                                break;
                        }
                }
+               ldap_pvt_thread_mutex_unlock( &connections_mutex );
        }
 #endif
 
        if( c != NULL ) {
                ber_socket_t    sd;
 
-               assert( c->c_struct_state != SLAP_C_UNINITIALIZED );
-
                ldap_pvt_thread_mutex_lock( &c->c_mutex );
 
+               assert( c->c_struct_state != SLAP_C_UNINITIALIZED );
+
                ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_GET_FD, &sd );
+#ifdef HAVE_WINSOCK
+               /* Avoid race condition after releasing
+                * connections_mutex
+                */
+               if ( sd != s ) {
+                       ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+                       return NULL;
+               }
+#endif
                if( c->c_struct_state != SLAP_C_USED ) {
                        /* connection must have been closed due to resched */
 
@@ -528,6 +370,7 @@ long connection_init(
 {
        unsigned long id;
        Connection *c;
+       int doinit = 0;
 
        assert( connections != NULL );
 
@@ -548,24 +391,29 @@ long connection_init(
        assert( s >= 0 );
 #ifndef HAVE_WINSOCK
        assert( s < dtblsize );
-#endif
-
-       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX(s) );
-
-#ifndef HAVE_WINSOCK
-       assert( MCA_conn_check( s ) );
-       c = MCA_GET_CONNECTION(s);
+       c = &connections[s];
+       if( c->c_struct_state == SLAP_C_UNINITIALIZED ) {
+               doinit = 1;
+       } else {
+               assert( c->c_struct_state == SLAP_C_UNUSED );
+       }
 #else
        {
                ber_socket_t i;
                c = NULL;
 
+               ldap_pvt_thread_mutex_lock( &connections_mutex );
                for( i=0; i < dtblsize; i++) {
                        ber_socket_t    sd;
 
+                       if ( connections[i].c_struct_state == SLAP_C_PENDING )
+                               continue;
+
                        if( connections[i].c_struct_state == SLAP_C_UNINITIALIZED ) {
                                assert( connections[i].c_sb == 0 );
                                c = &connections[i];
+                               c->c_struct_state = SLAP_C_PENDING;
+                               doinit = 1;
                                break;
                        }
 
@@ -578,6 +426,7 @@ long connection_init(
                        if( connections[i].c_struct_state == SLAP_C_UNUSED ) {
                                assert( sd == AC_SOCKET_INVALID );
                                c = &connections[i];
+                               c->c_struct_state = SLAP_C_PENDING;
                                break;
                        }
 
@@ -587,20 +436,18 @@ long connection_init(
                        assert( connections[i].c_conn_state != SLAP_C_INVALID );
                        assert( sd != AC_SOCKET_INVALID );
                }
+               ldap_pvt_thread_mutex_unlock( &connections_mutex );
 
                if( c == NULL ) {
                        Debug( LDAP_DEBUG_ANY,
                                "connection_init(%d): connection table full "
                                "(%d/%d)\n", s, i, dtblsize);
-                       ldap_pvt_thread_mutex_unlock( &connections_mutex );
                        return -1;
                }
        }
 #endif
 
-       assert( c != NULL );
-
-       if( c->c_struct_state == SLAP_C_UNINITIALIZED ) {
+       if( doinit ) {
                c->c_send_ldap_result = slap_send_ldap_result;
                c->c_send_search_entry = slap_send_search_entry;
                c->c_send_search_reference = slap_send_search_reference;
@@ -650,13 +497,10 @@ long connection_init(
                        slapi_int_create_object_extensions( SLAPI_X_EXT_CONNECTION, c );
                }
 #endif
-
-               c->c_struct_state = SLAP_C_UNUSED;
        }
 
        ldap_pvt_thread_mutex_lock( &c->c_mutex );
 
-       assert( c->c_struct_state == SLAP_C_UNUSED );
        assert( BER_BVISNULL( &c->c_authmech ) );
        assert( BER_BVISNULL( &c->c_dn ) );
        assert( BER_BVISNULL( &c->c_ndn ) );
@@ -687,7 +531,6 @@ long connection_init(
                c->c_close_reason = "?";                        /* should never be needed */
                ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_SET_FD, &s );
                ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
 
                return 0;
        }
@@ -776,7 +619,6 @@ long connection_init(
 
        slapd_add_internal( s, 1 );
        ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
 
        backend_connection_init(c);
 
@@ -819,10 +661,10 @@ void connection2anonymous( Connection *c )
 static void
 connection_destroy( Connection *c )
 {
-       /* note: connections_mutex should be locked by caller */
        ber_socket_t    sd;
        unsigned long   connid;
        const char              *close_reason;
+       Sockbuf                 *sb;
 
        assert( connections != NULL );
        assert( c != NULL );
@@ -841,6 +683,10 @@ connection_destroy( Connection *c )
        connid = c->c_connid;
        close_reason = c->c_close_reason;
 
+       ldap_pvt_thread_mutex_lock( &connections_mutex );
+       c->c_struct_state = SLAP_C_PENDING;
+       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+
        backend_connection_destroy(c);
 
        c->c_protocol = 0;
@@ -873,37 +719,40 @@ connection_destroy( Connection *c )
                c->c_currentber = NULL;
        }
 
-       ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_GET_FD, &sd );
-       slapd_sd_lock();
-       ber_sockbuf_free( c->c_sb );
-       if ( sd != AC_SOCKET_INVALID ) {
-               slapd_remove( sd, 1, 0, 1 );
 
-               Statslog( LDAP_DEBUG_STATS, (close_reason
-                                                                        ? "conn=%lu fd=%ld closed (%s)\n"
-                                                                        : "conn=%lu fd=%ld closed\n"),
-                       connid, (long) sd, close_reason, 0, 0 );
-       } else {
-               slapd_sd_unlock();
+#ifdef LDAP_SLAPI
+       /* call destructors, then constructors; avoids unnecessary allocation */
+       if ( slapi_plugins_used ) {
+               slapi_int_clear_object_extensions( SLAPI_X_EXT_CONNECTION, c );
        }
+#endif
 
-       c->c_sb = ber_sockbuf_alloc( );
+       c->c_conn_state = SLAP_C_INVALID;
+       c->c_struct_state = SLAP_C_UNUSED;
+       c->c_close_reason = "?";                        /* should never be needed */
 
+       sb = c->c_sb;
+       c->c_sb = ber_sockbuf_alloc( );
        {
                ber_len_t max = sockbuf_max_incoming;
                ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_SET_MAX_INCOMING, &max );
        }
 
-       c->c_conn_state = SLAP_C_INVALID;
-       c->c_struct_state = SLAP_C_UNUSED;
-       c->c_close_reason = "?";                        /* should never be needed */
+       ber_sockbuf_ctrl( sb, LBER_SB_OPT_GET_FD, &sd );
 
-#ifdef LDAP_SLAPI
-       /* call destructors, then constructors; avoids unnecessary allocation */
-       if ( slapi_plugins_used ) {
-               slapi_int_clear_object_extensions( SLAPI_X_EXT_CONNECTION, c );
+       /* c must be fully reset by this point; when we call slapd_remove
+        * it may get immediately reused by a new connection.
+        */
+       if ( sd != AC_SOCKET_INVALID ) {
+               slapd_remove( sd, sb, 1, 0, 0 );
+
+               if ( close_reason == NULL ) {
+                       close_reason = "";
+               }
+
+               Statslog( LDAP_DEBUG_STATS, "conn=%lu fd=%ld closed (%s)\n",
+                       connid, (long) sd, close_reason, 0, 0 );
        }
-#endif
 }
 
 int connection_state_closing( Connection *c )
@@ -984,18 +833,25 @@ void connection_closing( Connection *c, const char *why )
                c->c_close_reason = why;
 
                /* don't listen on this port anymore */
-               slapd_clr_read( sd, 1 );
+               slapd_clr_read( sd, 0 );
 
                /* abandon active operations */
                connection_abandon( c );
 
                /* wake write blocked operations */
-               slapd_clr_write( sd, 1 );
                if ( c->c_writewaiter ) {
                        ldap_pvt_thread_cond_signal( &c->c_write_cv );
+                       /* ITS#4667 this may allow another thread to drop into
+                        * connection_resched / connection_close before we
+                        * finish, but that's OK.
+                        */
+                       slapd_clr_write( sd, 1 );
                        ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-                       ldap_pvt_thread_yield();
+                       ldap_pvt_thread_mutex_lock( &c->c_write_mutex );
                        ldap_pvt_thread_mutex_lock( &c->c_mutex );
+                       ldap_pvt_thread_mutex_unlock( &c->c_write_mutex );
+               } else {
+                       slapd_clr_write( sd, 1 );
                }
 
        } else if( why == NULL && c->c_close_reason == conn_lost_str ) {
@@ -1004,19 +860,31 @@ void connection_closing( Connection *c, const char *why )
        }
 }
 
-static void connection_close( Connection *c )
+static void
+connection_close( Connection *c )
 {
-       ber_socket_t    sd;
+       ber_socket_t    sd = AC_SOCKET_INVALID;
 
        assert( connections != NULL );
        assert( c != NULL );
+
+       /* ITS#4667 we may have gotten here twice */
+       if ( c->c_conn_state == SLAP_C_INVALID )
+               return;
+
        assert( c->c_struct_state == SLAP_C_USED );
        assert( c->c_conn_state == SLAP_C_CLOSING );
 
-       /* note: connections_mutex and c_mutex should be locked by caller */
+       /* NOTE: c_mutex should be locked by caller */
 
-       ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_GET_FD, &sd );
-       if( !LDAP_STAILQ_EMPTY(&c->c_ops) ) {
+       /* NOTE: don't get the file descriptor if not needed */
+       if ( LogTest( LDAP_DEBUG_TRACE ) ) {
+               ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_GET_FD, &sd );
+       }
+
+       if ( !LDAP_STAILQ_EMPTY(&c->c_ops) ||
+               !LDAP_STAILQ_EMPTY(&c->c_pending_ops) )
+       {
                Debug( LDAP_DEBUG_TRACE,
                        "connection_close: deferring conn=%lu sd=%d\n",
                        c->c_connid, sd, 0 );
@@ -1025,6 +893,7 @@ static void connection_close( Connection *c )
 
        Debug( LDAP_DEBUG_TRACE, "connection_close: conn=%lu sd=%d\n",
                c->c_connid, sd, 0 );
+
        connection_destroy( c );
 }
 
@@ -1044,71 +913,21 @@ unsigned long connections_nextid(void)
 
 Connection* connection_first( ber_socket_t *index )
 {
-#ifdef SLAP_MULTI_CONN_ARRAY
-       int conn_array_id;
-#endif
-
        assert( connections != NULL );
        assert( index != NULL );
 
-#ifdef SLAP_MULTI_CONN_ARRAY
-       for ( conn_array_id = 0;
-               conn_array_id < NUM_CONNECTION_ARRAY;
-               conn_array_id++ )
-       {
-               ldap_pvt_thread_mutex_lock( &connections_mutex[ conn_array_id ] );
-       }
-#else
        ldap_pvt_thread_mutex_lock( &connections_mutex );
-#endif
-
-       *index = 0;
-
-       return connection_next(NULL, index);
-}
-
-Connection* connection_next( Connection *c, ber_socket_t *index )
-#ifdef SLAP_MULTI_CONN_ARRAY
-{
-       Connection* conn;
-
-       assert( connections != NULL );
-       assert( index != NULL );
-       assert( *index >= 0 && *index <= dtblsize );
-
-       if( c != NULL ) ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-
-       c = NULL;
-
-       for(; *index < dtblsize; (*index)++) {
-               assert( MCA_conn_check( *index ) );
-               conn = MCA_GET_CONNECTION(*index);
-               if( conn->c_struct_state == SLAP_C_UNINITIALIZED ) {
-                       assert( conn->c_conn_state == SLAP_C_INVALID );
-#ifndef HAVE_WINSOCK
-                       continue;
-#else
+       for( *index = 0; *index < dtblsize; (*index)++) {
+               if( connections[*index].c_struct_state != SLAP_C_UNINITIALIZED ) {
                        break;
-#endif
                }
-
-               if( conn->c_struct_state == SLAP_C_USED ) {
-                       assert( conn->c_conn_state != SLAP_C_INVALID );
-                       c = conn;
-                       (*index)++;
-                       break;
-               }
-
-               assert( conn->c_struct_state == SLAP_C_UNUSED );
-               assert( conn->c_conn_state == SLAP_C_INVALID );
        }
+       ldap_pvt_thread_mutex_unlock( &connections_mutex );
 
-       if( c != NULL ) ldap_pvt_thread_mutex_lock( &c->c_mutex );
-
-       return c;
-
+       return connection_next(NULL, index);
 }
-#else
+
+Connection* connection_next( Connection *c, ber_socket_t *index )
 {
        assert( connections != NULL );
        assert( index != NULL );
@@ -1118,51 +937,51 @@ Connection* connection_next( Connection *c, ber_socket_t *index )
 
        c = NULL;
 
+       ldap_pvt_thread_mutex_lock( &connections_mutex );
        for(; *index < dtblsize; (*index)++) {
+               int c_struct;
                if( connections[*index].c_struct_state == SLAP_C_UNINITIALIZED ) {
                        assert( connections[*index].c_conn_state == SLAP_C_INVALID );
-#ifndef HAVE_WINSOCK
-                       continue;
-#else
+#ifdef HAVE_WINSOCK
                        break;
+#else
+                       continue;
 #endif
                }
 
                if( connections[*index].c_struct_state == SLAP_C_USED ) {
                        assert( connections[*index].c_conn_state != SLAP_C_INVALID );
                        c = &connections[(*index)++];
+                       if ( ldap_pvt_thread_mutex_trylock( &c->c_mutex )) {
+                               /* avoid deadlock */
+                               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+                               ldap_pvt_thread_mutex_lock( &c->c_mutex );
+                               ldap_pvt_thread_mutex_lock( &connections_mutex );
+                               if ( c->c_struct_state != SLAP_C_USED ) {
+                                       ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+                                       c = NULL;
+                                       continue;
+                               }
+                       }
                        break;
                }
 
-               assert( connections[*index].c_struct_state == SLAP_C_UNUSED );
+               c_struct = connections[*index].c_struct_state;
+               if ( c_struct == SLAP_C_PENDING )
+                       continue;
+               assert( c_struct == SLAP_C_UNUSED );
                assert( connections[*index].c_conn_state == SLAP_C_INVALID );
        }
 
-       if( c != NULL ) ldap_pvt_thread_mutex_lock( &c->c_mutex );
+       ldap_pvt_thread_mutex_unlock( &connections_mutex );
        return c;
 }
-#endif
 
 void connection_done( Connection *c )
 {
-#ifdef SLAP_MULTI_CONN_ARRAY
-       int conn_array_id;
-#endif
-
        assert( connections != NULL );
 
        if( c != NULL ) ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-
-#ifdef SLAP_MULTI_CONN_ARRAY
-       for ( conn_array_id = 0;
-               conn_array_id < NUM_CONNECTION_ARRAY;
-               conn_array_id++ )
-       {
-               ldap_pvt_thread_mutex_unlock( &connections_mutex[ conn_array_id ] );
-       }
-#else
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
-#endif
 }
 
 /*
@@ -1199,7 +1018,7 @@ void connection_done( Connection *c )
 /*
  * NOTE: keep in sync with enum in slapd.h
  */
-static int (*opfun[])( Operation *op, SlapReply *rs ) = {
+static BI_op_func *opfun[] = {
        do_bind,
        do_unbind,
        do_add,
@@ -1220,7 +1039,7 @@ connection_operation( void *ctx, void *arg_v )
        Operation *op = arg_v;
        SlapReply rs = {REP_RESULT};
        ber_tag_t tag = op->o_tag;
-       int opidx = -1;
+       slap_op_t opidx = SLAP_OP_LAST;
        Connection *conn = op->o_conn;
        void *memctx = NULL;
        void *memctx_null = NULL;
@@ -1303,53 +1122,8 @@ connection_operation( void *ctx, void *arg_v )
        }
        }
 
-       switch ( tag ) {
-       case LDAP_REQ_BIND:
-               opidx = SLAP_OP_BIND;
-               break;
-
-       case LDAP_REQ_UNBIND:
-               opidx = SLAP_OP_UNBIND;
-               break;
-
-       case LDAP_REQ_ADD:
-               opidx = SLAP_OP_ADD;
-               break;
-
-       case LDAP_REQ_DELETE:
-               opidx = SLAP_OP_DELETE;
-               break;
-
-       case LDAP_REQ_MODRDN:
-               opidx = SLAP_OP_MODRDN;
-               break;
-
-       case LDAP_REQ_MODIFY:
-               opidx = SLAP_OP_MODIFY;
-               break;
-
-       case LDAP_REQ_COMPARE:
-               opidx = SLAP_OP_COMPARE;
-               break;
-
-       case LDAP_REQ_SEARCH:
-               opidx = SLAP_OP_SEARCH;
-               break;
-
-       case LDAP_REQ_ABANDON:
-               opidx = SLAP_OP_ABANDON;
-               break;
-
-       case LDAP_REQ_EXTENDED:
-               opidx = SLAP_OP_EXTENDED;
-               break;
-
-       default:
-               /* not reachable */
-               assert( 0 );
-       }
-
-       assert( opidx > -1 );
+       opidx = slap_req2op( tag );
+       assert( opidx != SLAP_OP_LAST );
        INCR_OP_INITIATED( opidx );
        rc = (*(opfun[opidx]))( op, &rs );
 
@@ -1357,7 +1131,7 @@ operations_error:
        if ( rc == SLAPD_DISCONNECT ) {
                tag = LBER_ERROR;
 
-       } else if ( opidx > -1 ) {
+       } else if ( opidx != SLAP_OP_LAST ) {
                /* increment completed operations count 
                 * only if operation was initiated
                 * and rc != SLAPD_DISCONNECT */
@@ -1371,6 +1145,7 @@ operations_error:
                        op->o_cancel = LDAP_TOO_LATE;
                }
        }
+
        while ( op->o_cancel != SLAP_CANCEL_NONE &&
                op->o_cancel != SLAP_CANCEL_DONE )
        {
@@ -1435,6 +1210,7 @@ void connection_client_stop(
        ber_socket_t s )
 {
        Connection *c;
+       Sockbuf *sb;
 
        /* get (locked) connection */
        c = connection_get( s );
@@ -1445,14 +1221,13 @@ void connection_client_stop(
        c->c_conn_state = SLAP_C_INVALID;
        c->c_struct_state = SLAP_C_UNUSED;
        c->c_close_reason = "?";                        /* should never be needed */
-       slapd_sd_lock();
-       ber_sockbuf_free( c->c_sb );
-       slapd_remove( s, 0, 1, 1 );
+       sb = c->c_sb;
        c->c_sb = ber_sockbuf_alloc( );
        {
                ber_len_t max = sockbuf_max_incoming;
                ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_SET_MAX_INCOMING, &max );
        }
+       slapd_remove( s, sb, 0, 1, 0 );
 
        connection_return( c );
 }
@@ -1524,8 +1299,6 @@ int connection_read(ber_socket_t s)
 
        assert( connections != NULL );
 
-       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX(s) );
-
        /* get (locked) connection */
        c = connection_get( s );
 
@@ -1534,7 +1307,6 @@ int connection_read(ber_socket_t s)
                        "connection_read(%ld): no connection!\n",
                        (long) s, 0, 0 );
 
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return -1;
        }
 
@@ -1544,12 +1316,7 @@ int connection_read(ber_socket_t s)
                Debug( LDAP_DEBUG_TRACE,
                        "connection_read(%d): closing, ignoring input for id=%lu\n",
                        s, c->c_connid, 0 );
-
-#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
-               slapd_set_read( s, 1 );
-#endif
                connection_return( c );
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
@@ -1564,7 +1331,6 @@ int connection_read(ber_socket_t s)
                        c->c_clientfunc, c->c_clientarg );
 #endif
                connection_return( c );
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
@@ -1582,31 +1348,10 @@ int connection_read(ber_socket_t s)
                                s, rc, c->c_connid );
 
                        c->c_needs_tls_accept = 0;
-                       /* connections_mutex and c_mutex are locked */
+                       /* c_mutex is locked */
                        connection_closing( c, "TLS negotiation failure" );
-
-#if 0
-                       {
-                               struct timeval tv;
-                               fd_set rfd;
-                               /* Drain input before close, to allow SSL error codes
-                                * to propagate to client. */
-                               FD_ZERO(&rfd);
-                               FD_SET(s, &rfd);
-                               for (rc=1; rc>0;) {
-                                       tv.tv_sec = 1;
-                                       tv.tv_usec = 0;
-                                       rc = select(s+1, &rfd, NULL, NULL, &tv);
-                                       if (rc == 1) {
-                                               ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_DRAIN, NULL);
-                                       }
-                               }
-                       }
-#endif
-
                        connection_close( c );
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
 
                } else if ( rc == 0 ) {
@@ -1637,15 +1382,13 @@ int connection_read(ber_socket_t s)
                }
 
                /* if success and data is ready, fall thru to data input loop */
-               if( rc != 0 ||
-                       !ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_DATA_READY, NULL ) )
+               if( !ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_DATA_READY, NULL ) )
                {
 #ifdef SLAP_LIGHTWEIGHT_DISPATCHER
                        slapd_set_read( s, 1 );
 #endif
 
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
        }
@@ -1660,7 +1403,6 @@ int connection_read(ber_socket_t s)
 #endif
 
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
 
@@ -1673,11 +1415,10 @@ int connection_read(ber_socket_t s)
                                "error=%d id=%lu, closing\n",
                                s, rc, c->c_connid );
 
-                       /* connections_mutex and c_mutex are locked */
+                       /* c_mutex is locked */
                        connection_closing( c, "SASL layer install failure" );
                        connection_close( c );
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
        }
@@ -1703,15 +1444,14 @@ int connection_read(ber_socket_t s)
 #endif
 
        if( rc < 0 ) {
-               Debug( LDAP_DEBUG_TRACE,
+               Debug( LDAP_DEBUG_CONNS,
                        "connection_read(%d): input error=%d id=%lu, closing.\n",
                        s, rc, c->c_connid );
 
-               /* connections_mutex and c_mutex are locked */
+               /* c_mutex is locked */
                connection_closing( c, conn_lost_str );
                connection_close( c );
                connection_return( c );
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
@@ -1732,7 +1472,6 @@ int connection_read(ber_socket_t s)
 #endif
 
        connection_return( c );
-       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
 
        return 0;
 }
@@ -1763,7 +1502,7 @@ connection_input( Connection *conn )
                return -1;
        }
 
-       errno = 0;
+       sock_errset(0);
 
 #ifdef LDAP_CONNECTIONLESS
        if ( conn->c_is_udp ) {
@@ -1783,16 +1522,16 @@ connection_input( Connection *conn )
 
        tag = ber_get_next( conn->c_sb, &len, conn->c_currentber );
        if ( tag != LDAP_TAG_MESSAGE ) {
-               int err = errno;
+               int err = sock_errno();
                ber_socket_t    sd;
 
                ber_sockbuf_ctrl( conn->c_sb, LBER_SB_OPT_GET_FD, &sd );
 
-               Debug( LDAP_DEBUG_TRACE,
-                       "ber_get_next on fd %d failed errno=%d (%s)\n",
-                       sd, err, sock_errstr(err) );
                if ( err != EWOULDBLOCK && err != EAGAIN ) {
                        /* log, close and send error */
+                       Debug( LDAP_DEBUG_TRACE,
+                               "ber_get_next on fd %d failed errno=%d (%s)\n",
+                       sd, err, sock_errstr(err) );
                        ber_free( conn->c_currentber, 1 );
                        conn->c_currentber = NULL;
 
@@ -1969,39 +1708,13 @@ connection_resched( Connection *conn )
        Operation *op;
 
        if( conn->c_conn_state == SLAP_C_CLOSING ) {
-               int rc;
                ber_socket_t    sd;
                ber_sockbuf_ctrl( conn->c_sb, LBER_SB_OPT_GET_FD, &sd );
 
-               /* use trylock to avoid possible deadlock */
-               rc = ldap_pvt_thread_mutex_trylock( MCA_GET_CONN_MUTEX( sd ) );
-
-               if( rc ) {
-                       Debug( LDAP_DEBUG_TRACE,
-                               "connection_resched: reaquiring locks conn=%lu sd=%d\n",
-                               conn->c_connid, sd, 0 );
-                       /*
-                        * reaquire locks in the right order...
-                        * this may allow another thread to close this connection,
-                        * so recheck state below.
-                        */
-                       ldap_pvt_thread_mutex_unlock( &conn->c_mutex );
-                       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX ( sd ) );
-                       ldap_pvt_thread_mutex_lock( &conn->c_mutex );
-               }
-
-               if( conn->c_conn_state != SLAP_C_CLOSING ) {
-                       Debug( LDAP_DEBUG_TRACE, "connection_resched: "
-                               "closed by other thread conn=%lu sd=%d\n",
-                               conn->c_connid, sd, 0 );
-               } else {
-                       Debug( LDAP_DEBUG_TRACE, "connection_resched: "
-                               "attempting closing conn=%lu sd=%d\n",
-                               conn->c_connid, sd, 0 );
-                       connection_close( conn );
-               }
-
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX( sd ) );
+               Debug( LDAP_DEBUG_TRACE, "connection_resched: "
+                       "attempting closing conn=%lu sd=%d\n",
+                       conn->c_connid, sd, 0 );
+               connection_close( conn );
                return 0;
        }
 
@@ -2046,13 +1759,17 @@ static int connection_bind_cleanup_cb( Operation *op, SlapReply *rs )
 {
        op->o_conn->c_sasl_bindop = NULL;
 
+       ch_free( op->o_callback );
+       op->o_callback = NULL;
+
        return SLAP_CB_CONTINUE;
 }
 
 static int connection_bind_cb( Operation *op, SlapReply *rs )
 {
        ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
-       op->o_conn->c_conn_state = SLAP_C_ACTIVE;
+       if ( op->o_conn->c_conn_state == SLAP_C_BINDING )
+               op->o_conn->c_conn_state = SLAP_C_ACTIVE;
        op->o_conn->c_sasl_bind_in_progress =
                ( rs->sr_err == LDAP_SASL_BIND_IN_PROGRESS );
 
@@ -2181,14 +1898,11 @@ int connection_write(ber_socket_t s)
 
        slapd_clr_write( s, 0 );
 
-       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX( s ) );
-
        c = connection_get( s );
        if( c == NULL ) {
                Debug( LDAP_DEBUG_ANY,
                        "connection_write(%ld): no connection!\n",
                        (long)s, 0, 0 );
-               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX( s ) );
                return -1;
        }
 
@@ -2228,7 +1942,6 @@ int connection_write(ber_socket_t s)
        }
 
        connection_return( c );
-       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
        return 0;
 }