]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/connection.c
fd arrary bound check
[openldap] / servers / slapd / connection.c
index 6b1c055a22216f7db31a3c18b7e9d8df06e2d80b..7482ed4ce288bac84a840feec8a514db3aa0b820 100644 (file)
@@ -1,7 +1,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 1998-2004 The OpenLDAP Foundation.
+ * Copyright 1998-2006 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -26,7 +26,9 @@
 #include "portable.h"
 
 #include <stdio.h>
+#ifdef HAVE_LIMITS_H
 #include <limits.h>
+#endif
 
 #include <ac/socket.h>
 #include <ac/errno.h>
 #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;
 
+static const char conn_lost_str[] = "connection lost";
+
 /* structure state (protected by connections_mutex) */
 #define SLAP_C_UNINITIALIZED   0x00    /* MUST BE ZERO (0) */
 #define SLAP_C_UNUSED                  0x01
@@ -78,10 +105,25 @@ connection_state2str( int state )
 
 static Connection* connection_get( ber_socket_t s );
 
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+
+typedef struct conn_readinfo {
+       Operation *op;
+       ldap_pvt_thread_start_t *func;
+       void *arg;
+       int nullop;
+} conn_readinfo;
+
+static int connection_input( Connection *c, conn_readinfo *cri );
+#else
 static int connection_input( Connection *c );
+#endif
 static void connection_close( Connection *c );
 
 static int connection_op_activate( Operation *op );
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+static void connection_op_queue( Operation *op );
+#endif
 static int connection_resched( Connection *conn );
 static void connection_abandon( Connection *conn );
 static void connection_destroy( Connection *c );
@@ -92,6 +134,69 @@ 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;
 
@@ -110,8 +215,8 @@ int connections_init(void)
        connections = (Connection *) ch_calloc( dtblsize, sizeof(Connection) );
 
        if( connections == NULL ) {
-               Debug( LDAP_DEBUG_ANY,
-                       "connections_init: allocation (%d*%ld) of connection array failed\n",
+               Debug( LDAP_DEBUG_ANY, "connections_init: "
+                       "allocation (%d*%ld) of connection array failed\n",
                        dtblsize, (long) sizeof(Connection), 0 );
                return -1;
        }
@@ -128,11 +233,58 @@ 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
+                               /* FIX ME!! */
+                               if ( slapi_plugins_used ) {
+                                       slapi_int_free_object_extensions( SLAPI_X_EXT_CONNECTION,
+                                               &connections[i] );
+                               }
+#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;
 
@@ -152,7 +304,8 @@ int connections_destroy(void)
                        ldap_pvt_thread_cond_destroy( &connections[i].c_write_cv );
 #ifdef LDAP_SLAPI
                        if ( slapi_plugins_used ) {
-                               slapi_int_free_object_extensions( SLAPI_X_EXT_CONNECTION, &connections[i] );
+                               slapi_int_free_object_extensions( SLAPI_X_EXT_CONNECTION,
+                                       &connections[i] );
                        }
 #endif
                }
@@ -165,11 +318,45 @@ 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;
 
@@ -189,7 +376,7 @@ int connections_shutdown(void)
                ldap_pvt_thread_mutex_lock( &connections[i].c_mutex );
 
                /* connections_mutex and c_mutex are locked */
-               connection_closing( &connections[i] );
+               connection_closing( &connections[i], "slapd shutdown" );
                connection_close( &connections[i] );
 
                ldap_pvt_thread_mutex_unlock( &connections[i].c_mutex );
@@ -199,6 +386,7 @@ int connections_shutdown(void)
 
        return 0;
 }
+#endif
 
 /*
  * Timeout idle connections.
@@ -215,12 +403,13 @@ int connections_timeout_idle(time_t now)
        {
                /* Don't timeout a slow-running request or a persistent
                 * outbound connection */
-               if( c->c_n_ops_executing ||
-                       c->c_conn_state == SLAP_C_CLIENT ) continue;
+               if( c->c_n_ops_executing || c->c_conn_state == SLAP_C_CLIENT ) {
+                       continue;
+               }
 
                if( difftime( c->c_activitytime+global_idletimeout, now) < 0 ) {
                        /* close it */
-                       connection_closing( c );
+                       connection_closing( c, "idletimeout" );
                        connection_close( c );
                        i++;
                }
@@ -242,12 +431,11 @@ static Connection* connection_get( ber_socket_t s )
 
        assert( connections != NULL );
 
-       if(s == AC_SOCKET_INVALID) {
-               return NULL;
-       }
+       if(s == AC_SOCKET_INVALID) return NULL;
 
 #ifndef HAVE_WINSOCK
-       c = &connections[s];
+       assert( MCA_conn_check( s ) );
+       c = MCA_GET_CONNECTION(s);
 
        assert( c->c_struct_state != SLAP_C_UNINITIALIZED );
 
@@ -363,11 +551,11 @@ long connection_init(
        assert( s < dtblsize );
 #endif
 
-       ldap_pvt_thread_mutex_lock( &connections_mutex );
+       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX(s) );
 
 #ifndef HAVE_WINSOCK
-       c = &connections[s];
-
+       assert( MCA_conn_check( s ) );
+       c = MCA_GET_CONNECTION(s);
 #else
        {
                ber_socket_t i;
@@ -394,9 +582,7 @@ long connection_init(
                                break;
                        }
 
-                       if( connections[i].c_conn_state == SLAP_C_CLIENT ) {
-                               continue;
-                       }
+                       if( connections[i].c_conn_state == SLAP_C_CLIENT ) continue;
 
                        assert( connections[i].c_struct_state == SLAP_C_USED );
                        assert( connections[i].c_conn_state != SLAP_C_INVALID );
@@ -420,9 +606,7 @@ long connection_init(
                c->c_send_search_entry = slap_send_search_entry;
                c->c_send_search_reference = slap_send_search_reference;
                c->c_send_ldap_extended = slap_send_ldap_extended;
-#ifdef LDAP_RES_INTERMEDIATE
                c->c_send_ldap_intermediate = slap_send_ldap_intermediate;
-#endif
 
                BER_BVZERO( &c->c_authmech );
                BER_BVZERO( &c->c_dn );
@@ -490,9 +674,10 @@ long connection_init(
        if ( flags == CONN_IS_CLIENT ) {
                c->c_conn_state = SLAP_C_CLIENT;
                c->c_struct_state = SLAP_C_USED;
+               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( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
 
                return 0;
        }
@@ -561,6 +746,7 @@ long connection_init(
 
        c->c_conn_state = SLAP_C_INACTIVE;
        c->c_struct_state = SLAP_C_USED;
+       c->c_close_reason = "?";                        /* should never be needed */
 
        c->c_ssf = c->c_transport_ssf = ssf;
        c->c_tls_ssf = 0;
@@ -578,8 +764,9 @@ long connection_init(
        slap_sasl_open( c, 0 );
        slap_sasl_external( c, ssf, authid );
 
+       slapd_add_internal( s, 1 );
        ldap_pvt_thread_mutex_unlock( &c->c_mutex );
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
 
        backend_connection_init(c);
 
@@ -596,20 +783,26 @@ void connection2anonymous( Connection *c )
                ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_SET_MAX_INCOMING, &max );
        }
 
-       if(c->c_authmech.bv_val != NULL ) {
-               free(c->c_authmech.bv_val);
+       if ( !BER_BVISNULL( &c->c_authmech ) ) {
+               ch_free(c->c_authmech.bv_val);
        }
        BER_BVZERO( &c->c_authmech );
 
-       if(c->c_dn.bv_val != NULL) {
-               free(c->c_dn.bv_val);
+       if ( !BER_BVISNULL( &c->c_dn ) ) {
+               ch_free(c->c_dn.bv_val);
        }
        BER_BVZERO( &c->c_dn );
-       if(c->c_ndn.bv_val != NULL) {
-               free(c->c_ndn.bv_val);
+
+       if ( !BER_BVISNULL( &c->c_ndn ) ) {
+               ch_free(c->c_ndn.bv_val);
        }
        BER_BVZERO( &c->c_ndn );
 
+       if ( !BER_BVISNULL( &c->c_sasl_authz_dn ) ) {
+               ber_memfree_x( c->c_sasl_authz_dn.bv_val, NULL );
+       }
+       BER_BVZERO( &c->c_sasl_authz_dn );
+
        c->c_authz_backend = NULL;
 }
 
@@ -619,6 +812,7 @@ connection_destroy( Connection *c )
        /* note: connections_mutex should be locked by caller */
        ber_socket_t    sd;
        unsigned long   connid;
+       const char              *close_reason;
 
        assert( connections != NULL );
        assert( c != NULL );
@@ -629,6 +823,7 @@ connection_destroy( Connection *c )
 
        /* only for stats (print -1 as "%lu" may give unexpected results ;) */
        connid = c->c_connid;
+       close_reason = c->c_close_reason;
 
        backend_connection_destroy(c);
 
@@ -663,16 +858,19 @@ connection_destroy( Connection *c )
        }
 
        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 );
+               slapd_remove( sd, 1, 0, 1 );
 
-               Statslog( LDAP_DEBUG_STATS,
-                       "conn=%lu fd=%ld closed\n",
-                       connid, (long) sd, 0, 0, 0 );
+               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();
        }
 
-       ber_sockbuf_free( c->c_sb );
-
        c->c_sb = ber_sockbuf_alloc( );
 
        {
@@ -682,6 +880,7 @@ connection_destroy( Connection *c )
 
        c->c_conn_state = SLAP_C_INVALID;
        c->c_struct_state = SLAP_C_UNUSED;
+       c->c_close_reason = "?";                        /* should never be needed */
 
 #ifdef LDAP_SLAPI
        /* call destructors, then constructors; avoids unnecessary allocation */
@@ -710,10 +909,20 @@ static void connection_abandon( Connection *c )
 {
        /* c_mutex must be locked by caller */
 
-       Operation *o;
-
-       LDAP_STAILQ_FOREACH(o, &c->c_ops, o_next) {
+       Operation *o, *next, op = {0};
+       Opheader ohdr = {0};
+       SlapReply rs = {0};
+
+       op.o_hdr = &ohdr;
+       op.o_conn = c;
+       op.o_connid = c->c_connid;
+       op.o_tag = LDAP_REQ_ABANDON;
+       for ( o = LDAP_STAILQ_FIRST( &c->c_ops ); o; o=next ) {
+               next = LDAP_STAILQ_NEXT( o, o_next );
+               op.orn_msgid = o->o_msgid;
                o->o_abandon = 1;
+               op.o_bd = frontendDB;
+               frontendDB->be_abandon( &op, &rs );
        }
 
        /* remove pending operations */
@@ -724,7 +933,7 @@ static void connection_abandon( Connection *c )
        }
 }
 
-void connection_closing( Connection *c )
+void connection_closing( Connection *c, const char *why )
 {
        assert( connections != NULL );
        assert( c != NULL );
@@ -742,6 +951,7 @@ void connection_closing( Connection *c )
                        c->c_connid, sd, 0 );
                /* update state to closing */
                c->c_conn_state = SLAP_C_CLOSING;
+               c->c_close_reason = why;
 
                /* don't listen on this port anymore */
                slapd_clr_read( sd, 1 );
@@ -751,7 +961,15 @@ void connection_closing( Connection *c )
 
                /* wake write blocked operations */
                slapd_clr_write( sd, 1 );
-               ldap_pvt_thread_cond_signal( &c->c_write_cv );
+               if ( c->c_writewaiter ) {
+                       ldap_pvt_thread_cond_signal( &c->c_write_cv );
+                       ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+                       ldap_pvt_thread_yield();
+                       ldap_pvt_thread_mutex_lock( &c->c_mutex );
+               }
+       } else if( why == NULL && c->c_close_reason == conn_lost_str ) {
+               /* Client closed connection after doing Unbind. */
+               c->c_close_reason = NULL;
        }
 }
 
@@ -784,21 +1002,34 @@ unsigned long connections_nextid(void)
        unsigned long id;
        assert( connections != NULL );
 
-       ldap_pvt_thread_mutex_lock( &connections_mutex );
+       ldap_pvt_thread_mutex_lock( &conn_nextid_mutex );
 
        id = conn_nextid;
 
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+       ldap_pvt_thread_mutex_unlock( &conn_nextid_mutex );
 
        return id;
 }
 
 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;
 
@@ -806,15 +1037,54 @@ Connection* connection_first( ber_socket_t *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 <= dtblsize );
+       assert( *index >= 0 && *index <= dtblsize );
 
-       if( c != NULL ) {
-               ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+       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
+                       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 );
        }
 
+       if( c != NULL ) ldap_pvt_thread_mutex_lock( &c->c_mutex );
+
+       return c;
+
+}
+#else
+{
+       assert( connections != NULL );
+       assert( index != NULL );
+       assert( *index <= dtblsize );
+
+       if( c != NULL ) ldap_pvt_thread_mutex_unlock( &c->c_mutex );
+
        c = NULL;
 
        for(; *index < dtblsize; (*index)++) {
@@ -837,22 +1107,31 @@ Connection* connection_next( Connection *c, ber_socket_t *index )
                assert( connections[*index].c_conn_state == SLAP_C_INVALID );
        }
 
-       if( c != NULL ) {
-               ldap_pvt_thread_mutex_lock( &c->c_mutex );
-       }
-
+       if( c != NULL ) ldap_pvt_thread_mutex_lock( &c->c_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 );
-       }
+       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
 }
 
 /*
@@ -877,10 +1156,32 @@ void connection_done( Connection *c )
                ldap_pvt_thread_mutex_unlock( &slap_counters.sc_ops_mutex ); \
        } while (0)
 #else /* !SLAPD_MONITOR */
-#define INCR_OP_INITIATED(index) 
-#define INCR_OP_COMPLETED(index) 
+#define INCR_OP_INITIATED(index) do { } while (0)
+#define INCR_OP_COMPLETED(index) \
+       do { \
+               ldap_pvt_thread_mutex_lock( &slap_counters.sc_ops_mutex ); \
+               ldap_pvt_mp_add_ulong(slap_counters.sc_ops_completed, 1); \
+               ldap_pvt_thread_mutex_unlock( &slap_counters.sc_ops_mutex ); \
+       } while (0)
 #endif /* !SLAPD_MONITOR */
 
+/*
+ * NOTE: keep in sync with enum in slapd.h
+ */
+static int (*opfun[])( Operation *op, SlapReply *rs ) = {
+       do_bind,
+       do_unbind,
+       do_add,
+       do_delete,
+       do_modrdn,
+       do_modify,
+       do_compare,
+       do_search,
+       do_abandon,
+       do_extended,
+       NULL
+};
+
 static void *
 connection_operation( void *ctx, void *arg_v )
 {
@@ -888,9 +1189,7 @@ connection_operation( void *ctx, void *arg_v )
        Operation *op = arg_v;
        SlapReply rs = {REP_RESULT};
        ber_tag_t tag = op->o_tag;
-#ifdef SLAPD_MONITOR
-       ber_tag_t oldtag = tag;
-#endif /* SLAPD_MONITOR */
+       int opidx = -1;
        Connection *conn = op->o_conn;
        void *memctx = NULL;
        void *memctx_null = NULL;
@@ -908,7 +1207,7 @@ connection_operation( void *ctx, void *arg_v )
        case LDAP_REQ_UNBIND:
        case LDAP_REQ_ADD:
        case LDAP_REQ_DELETE:
-       case LDAP_REQ_MODRDN:
+       case LDAP_REQ_MODDN:
        case LDAP_REQ_MODIFY:
        case LDAP_REQ_COMPARE:
        case LDAP_REQ_SEARCH:
@@ -946,7 +1245,7 @@ connection_operation( void *ctx, void *arg_v )
 #endif
        memsiz = SLAP_SLAB_SIZE;
 
-       memctx = slap_sl_mem_create( memsiz, ctx );
+       memctx = slap_sl_mem_create( memsiz, SLAP_SLAB_STACK, ctx );
        op->o_tmpmemctx = memctx;
        op->o_tmpmfuncs = &slap_sl_mfuncs;
        if ( tag != LDAP_REQ_ADD && tag != LDAP_REQ_MODIFY ) {
@@ -959,53 +1258,43 @@ connection_operation( void *ctx, void *arg_v )
 
        switch ( tag ) {
        case LDAP_REQ_BIND:
-               INCR_OP_INITIATED(SLAP_OP_BIND);
-               rc = do_bind( op, &rs );
+               opidx = SLAP_OP_BIND;
                break;
 
        case LDAP_REQ_UNBIND:
-               INCR_OP_INITIATED(SLAP_OP_UNBIND);
-               rc = do_unbind( op, &rs );
+               opidx = SLAP_OP_UNBIND;
                break;
 
        case LDAP_REQ_ADD:
-               INCR_OP_INITIATED(SLAP_OP_ADD);
-               rc = do_add( op, &rs );
+               opidx = SLAP_OP_ADD;
                break;
 
        case LDAP_REQ_DELETE:
-               INCR_OP_INITIATED(SLAP_OP_DELETE);
-               rc = do_delete( op, &rs );
+               opidx = SLAP_OP_DELETE;
                break;
 
        case LDAP_REQ_MODRDN:
-               INCR_OP_INITIATED(SLAP_OP_MODRDN);
-               rc = do_modrdn( op, &rs );
+               opidx = SLAP_OP_MODRDN;
                break;
 
        case LDAP_REQ_MODIFY:
-               INCR_OP_INITIATED(SLAP_OP_MODIFY);
-               rc = do_modify( op, &rs );
+               opidx = SLAP_OP_MODIFY;
                break;
 
        case LDAP_REQ_COMPARE:
-               INCR_OP_INITIATED(SLAP_OP_COMPARE);
-               rc = do_compare( op, &rs );
+               opidx = SLAP_OP_COMPARE;
                break;
 
        case LDAP_REQ_SEARCH:
-               INCR_OP_INITIATED(SLAP_OP_SEARCH);
-               rc = do_search( op, &rs );
+               opidx = SLAP_OP_SEARCH;
                break;
 
        case LDAP_REQ_ABANDON:
-               INCR_OP_INITIATED(SLAP_OP_ABANDON);
-               rc = do_abandon( op, &rs );
+               opidx = SLAP_OP_ABANDON;
                break;
 
        case LDAP_REQ_EXTENDED:
-               INCR_OP_INITIATED(SLAP_OP_EXTENDED);
-               rc = do_extended( op, &rs );
+               opidx = SLAP_OP_EXTENDED;
                break;
 
        default:
@@ -1013,50 +1302,27 @@ connection_operation( void *ctx, void *arg_v )
                assert( 0 );
        }
 
+       assert( opidx > -1 );
+       INCR_OP_INITIATED( opidx );
+       rc = (*(opfun[opidx]))( op, &rs );
+
 operations_error:
-       if( rc == SLAPD_DISCONNECT ) tag = LBER_ERROR;
+       if ( rc == SLAPD_DISCONNECT ) {
+               tag = LBER_ERROR;
 
-#ifdef SLAPD_MONITOR
-       switch (oldtag) {
-       case LDAP_REQ_BIND:
-               INCR_OP_COMPLETED(SLAP_OP_BIND);
-               break;
-       case LDAP_REQ_UNBIND:
-               INCR_OP_COMPLETED(SLAP_OP_UNBIND);
-               break;
-       case LDAP_REQ_ADD:
-               INCR_OP_COMPLETED(SLAP_OP_ADD);
-               break;
-       case LDAP_REQ_DELETE:
-               INCR_OP_COMPLETED(SLAP_OP_DELETE);
-               break;
-       case LDAP_REQ_MODRDN:
-               INCR_OP_COMPLETED(SLAP_OP_MODRDN);
-               break;
-       case LDAP_REQ_MODIFY:
-               INCR_OP_COMPLETED(SLAP_OP_MODIFY);
-               break;
-       case LDAP_REQ_COMPARE:
-               INCR_OP_COMPLETED(SLAP_OP_COMPARE);
-               break;
-       case LDAP_REQ_SEARCH:
-               INCR_OP_COMPLETED(SLAP_OP_SEARCH);
-               break;
-       case LDAP_REQ_ABANDON:
-               INCR_OP_COMPLETED(SLAP_OP_ABANDON);
-               break;
-       case LDAP_REQ_EXTENDED:
-               INCR_OP_COMPLETED(SLAP_OP_EXTENDED);
-               break;
-       default:
-               /* not reachable */
-               assert( 0 );
+       } else if ( opidx > -1 ) {
+               /* increment completed operations count 
+                * only if operation was initiated
+                * and rc != SLAPD_DISCONNECT */
+               INCR_OP_COMPLETED( opidx );
        }
-#endif /* SLAPD_MONITOR */
-       ldap_pvt_thread_mutex_unlock( &slap_counters.sc_ops_mutex );
 
        if ( op->o_cancel == SLAP_CANCEL_REQ ) {
-               op->o_cancel = LDAP_TOO_LATE;
+               if ( rc == SLAPD_ABANDON ) {
+                       op->o_cancel = SLAP_CANCEL_ACK;
+               } else {
+                       op->o_cancel = LDAP_TOO_LATE;
+               }
        }
        while ( op->o_cancel != SLAP_CANCEL_NONE &&
                op->o_cancel != SLAP_CANCEL_DONE )
@@ -1068,40 +1334,19 @@ operations_error:
 
        ber_set_option( op->o_ber, LBER_OPT_BER_MEMCTX, &memctx_null );
 
-       if ( op->o_cancel != SLAP_CANCEL_ACK &&
-               ( op->o_sync_mode & SLAP_SYNC_PERSIST ) )
-       {
-               slap_sl_mem_detach( ctx, memctx );
-
-       } else if ( op->o_sync_slog_size != -1 ) {
-               slap_sl_mem_detach( ctx, memctx );
-               LDAP_STAILQ_REMOVE( &conn->c_ops, op, slap_op, o_next);
-               LDAP_STAILQ_NEXT(op, o_next) = NULL;
-               conn->c_n_ops_executing--;
-               conn->c_n_ops_completed++;
-
-       } else {
-               LDAP_STAILQ_REMOVE( &conn->c_ops, op, slap_op, o_next);
-               LDAP_STAILQ_NEXT(op, o_next) = NULL;
-               slap_op_free( op );
-               conn->c_n_ops_executing--;
-               conn->c_n_ops_completed++;
-       }
+       LDAP_STAILQ_REMOVE( &conn->c_ops, op, slap_op, o_next);
+       LDAP_STAILQ_NEXT(op, o_next) = NULL;
+       slap_op_free( op );
+       conn->c_n_ops_executing--;
+       conn->c_n_ops_completed++;
 
        switch( tag ) {
        case LBER_ERROR:
        case LDAP_REQ_UNBIND:
                /* c_mutex is locked */
-               connection_closing( conn );
+               connection_closing( conn,
+                       tag == LDAP_REQ_UNBIND ? NULL : "operations error" );
                break;
-
-       case LDAP_REQ_BIND:
-               conn->c_sasl_bind_in_progress =
-                       rc == LDAP_SASL_BIND_IN_PROGRESS ? 1 : 0;
-
-               if( conn->c_conn_state == SLAP_C_BINDING) {
-                       conn->c_conn_state = SLAP_C_ACTIVE;
-               }
        }
 
        connection_resched( conn );
@@ -1126,9 +1371,10 @@ int connection_client_setup(
        c = connection_get( s );
        c->c_clientfunc = func;
        c->c_clientarg = arg;
-       connection_return( c );
+
        slapd_add_internal( s, 0 );
        slapd_set_read( s, 1 );
+       connection_return( c );
        return 0;
 }
 
@@ -1151,18 +1397,87 @@ void connection_client_stop(
        c->c_listener = NULL;
        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 );
+       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 );
+       }
+
        connection_return( c );
-       slapd_remove( s, 0, 1 );
 }
 
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+
+static int connection_read( ber_socket_t s, conn_readinfo *cri );
+
+static void* connection_read_thread( void* ctx, void* argv )
+{
+       int rc ;
+       conn_readinfo cri = { NULL, NULL, NULL, 0 };
+       ber_socket_t s = (long)argv;
+
+       /*
+        * read incoming LDAP requests. If there is more than one,
+        * the first one is returned with new_op
+        */
+       if( ( rc = connection_read( s, &cri ) ) < 0 ) {
+               Debug( LDAP_DEBUG_CONNS, "connection_read(%d) error\n", s, 0, 0 );
+               return (void*)(long)rc;
+       }
+
+       /* execute a single queued request in the same thread */
+       if( cri.op && !cri.nullop ) {
+               rc = (long)connection_operation( ctx, cri.op );
+       } else if ( cri.func ) {
+               rc = (long)cri.func( ctx, cri.arg );
+       }
+
+       return (void*)(long)rc;
+}
+
+int connection_read_activate( ber_socket_t s )
+{
+       int rc;
+
+       /*
+        * suspend reading on this file descriptor until a connection processing
+        * thread reads data on it. Otherwise the listener thread will repeatedly
+        * submit the same event on it to the pool.
+        */
+       rc = slapd_clr_read( s, 0 );
+       if ( rc )
+               return rc;
+
+       rc = ldap_pvt_thread_pool_submit( &connection_pool,
+               connection_read_thread, (void *)(long)s );
+
+       if( rc != 0 ) {
+               Debug( LDAP_DEBUG_ANY,
+                       "connection_read_activate(%d): submit failed (%d)\n",
+                       s, rc, 0 );
+       }
+
+       return rc;
+}
+#endif
+
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+static int
+connection_read( ber_socket_t s, conn_readinfo *cri )
+#else
 int connection_read(ber_socket_t s)
+#endif
 {
        int rc = 0;
        Connection *c;
 
        assert( connections != NULL );
 
-       ldap_pvt_thread_mutex_lock( &connections_mutex );
+       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX(s) );
 
        /* get (locked) connection */
        c = connection_get( s );
@@ -1171,9 +1486,8 @@ int connection_read(ber_socket_t s)
                Debug( LDAP_DEBUG_ANY,
                        "connection_read(%ld): no connection!\n",
                        (long) s, 0, 0 );
-               slapd_remove(s, 1, 0);
 
-               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return -1;
        }
 
@@ -1183,17 +1497,27 @@ 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( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
        if ( c->c_conn_state == SLAP_C_CLIENT ) {
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+               cri->func = c->c_clientfunc;
+               cri->arg = c->c_clientarg;
+               /* read should already be cleared */
+#else
                slapd_clr_read( s, 0 );
                ldap_pvt_thread_pool_submit( &connection_pool,
                        c->c_clientfunc, c->c_clientarg );
+#endif
                connection_return( c );
-               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
@@ -1205,34 +1529,38 @@ int connection_read(ber_socket_t s)
        if ( c->c_is_tls && c->c_needs_tls_accept ) {
                rc = ldap_pvt_tls_accept( c->c_sb, slap_tls_ctx );
                if ( rc < 0 ) {
-#if 0 /* required by next #if 0 */
-                       struct timeval tv;
-                       fd_set rfd;
-#endif
-
                        Debug( LDAP_DEBUG_TRACE,
-                               "connection_read(%d): TLS accept error "
+                               "connection_read(%d): TLS accept failure "
                                "error=%d id=%lu, closing\n",
                                s, rc, c->c_connid );
+
                        c->c_needs_tls_accept = 0;
                        /* connections_mutex and c_mutex are locked */
-                       connection_closing( c );
+                       connection_closing( c, "TLS negotiation failure" );
 
 #if 0
-                       /* 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);
+                       {
+                               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 ) {
                        void *ssl;
@@ -1254,6 +1582,9 @@ int connection_read(ber_socket_t s)
                                        "unable to get TLS client DN, error=%d id=%lu\n",
                                        s, rc, c->c_connid );
                        }
+                       Statslog( LDAP_DEBUG_STATS,
+                               "conn=%lu fd=%d TLS established tls_ssf=%u ssf=%u\n",
+                           c->c_connid, (int) s, c->c_tls_ssf, c->c_ssf, 0 );
                        slap_sasl_external( c, c->c_tls_ssf, &authid );
                        if ( authid.bv_val ) free( authid.bv_val );
                }
@@ -1262,8 +1593,12 @@ int connection_read(ber_socket_t s)
                if( rc != 0 ||
                        !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( &connections_mutex );
+                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
        }
@@ -1273,25 +1608,29 @@ int connection_read(ber_socket_t s)
        if ( c->c_sasl_layers ) {
                /* If previous layer is not removed yet, give up for now */
                if ( !c->c_sasl_sockctx ) {
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+                       slapd_set_read( s, 1 );
+#endif
+
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
 
                c->c_sasl_layers = 0;
 
                rc = ldap_pvt_sasl_install( c->c_sb, c->c_sasl_sockctx );
-
                if( rc != LDAP_SUCCESS ) {
                        Debug( LDAP_DEBUG_TRACE,
                                "connection_read(%d): SASL install error "
                                "error=%d id=%lu, closing\n",
                                s, rc, c->c_connid );
+
                        /* connections_mutex and c_mutex are locked */
-                       connection_closing( c );
+                       connection_closing( c, "SASL layer install failure" );
                        connection_close( c );
                        connection_return( c );
-                       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+                       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                        return 0;
                }
        }
@@ -1302,7 +1641,11 @@ int connection_read(ber_socket_t s)
 
        do {
                /* How do we do this without getting into a busy loop ? */
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+               rc = connection_input( c, cri );
+#else
                rc = connection_input( c );
+#endif
        }
 #ifdef DATA_READY_LOOP
        while( !rc && ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_DATA_READY, NULL ));
@@ -1316,14 +1659,22 @@ int connection_read(ber_socket_t s)
                Debug( LDAP_DEBUG_TRACE,
                        "connection_read(%d): input error=%d id=%lu, closing.\n",
                        s, rc, c->c_connid );
+
                /* connections_mutex and c_mutex are locked */
-               connection_closing( c );
+               connection_closing( c, conn_lost_str );
                connection_close( c );
                connection_return( c );
-               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
                return 0;
        }
 
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+       if ( ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_NEEDS_WRITE, NULL ) ) {
+               slapd_set_write( s, 0 );
+       }
+
+       slapd_set_read( s, 1 );
+#else
        if ( ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_NEEDS_READ, NULL ) ) {
                slapd_set_read( s, 1 );
        }
@@ -1331,15 +1682,20 @@ int connection_read(ber_socket_t s)
        if ( ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_NEEDS_WRITE, NULL ) ) {
                slapd_set_write( s, 1 );
        }
+#endif
 
        connection_return( c );
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
+
        return 0;
 }
 
 static int
-connection_input(
-       Connection *conn )
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+connection_input( Connection *conn , conn_readinfo *cri )
+#else
+connection_input( Connection *conn )
+#endif
 {
        Operation *op;
        ber_tag_t       tag;
@@ -1364,11 +1720,11 @@ connection_input(
 
 #ifdef LDAP_CONNECTIONLESS
        if ( conn->c_is_udp ) {
-               char    peername[sizeof("IP=255.255.255.255:65336")];
-               len = ber_int_sb_read(conn->c_sb, &peeraddr,
-                       sizeof(struct sockaddr));
-               if (len != sizeof(struct sockaddr))
-                       return 1;
+               char peername[sizeof("IP=255.255.255.255:65336")];
+
+               len = ber_int_sb_read(conn->c_sb, &peeraddr, sizeof(struct sockaddr));
+               if (len != sizeof(struct sockaddr)) return 1;
+
                sprintf( peername, "IP=%s:%d",
                        inet_ntoa( peeraddr.sa_in_addr.sin_addr ),
                        (unsigned) ntohs( peeraddr.sa_in_addr.sin_port ) );
@@ -1377,6 +1733,7 @@ connection_input(
                        conn->c_connid, peername, conn->c_sock_name.bv_val, 0, 0 );
        }
 #endif
+
        tag = ber_get_next( conn->c_sb, &len, conn->c_currentber );
        if ( tag != LDAP_TAG_MESSAGE ) {
                int err = errno;
@@ -1402,16 +1759,14 @@ connection_input(
 
        if ( (tag = ber_get_int( ber, &msgid )) != LDAP_TAG_MSGID ) {
                /* log, close and send error */
-               Debug( LDAP_DEBUG_ANY, "ber_get_int returns 0x%lx\n",
-                       tag, 0, 0 );
+               Debug( LDAP_DEBUG_ANY, "ber_get_int returns 0x%lx\n", tag, 0, 0 );
                ber_free( ber, 1 );
                return -1;
        }
 
        if ( (tag = ber_peek_tag( ber, &len )) == LBER_ERROR ) {
                /* log, close and send error */
-               Debug( LDAP_DEBUG_ANY, "ber_peek_tag returns 0x%lx\n",
-                       tag, 0, 0 );
+               Debug( LDAP_DEBUG_ANY, "ber_peek_tag returns 0x%lx\n", tag, 0, 0 );
                ber_free( ber, 1 );
 
                return -1;
@@ -1430,8 +1785,9 @@ connection_input(
                }
        }
 #endif
+
        if(tag == LDAP_REQ_BIND) {
-               /* immediately abandon all exiting operations upon BIND */
+               /* immediately abandon all existing operations upon BIND */
                connection_abandon( conn );
        }
 
@@ -1440,7 +1796,8 @@ connection_input(
        op->o_conn = conn;
        /* clear state if the connection is being reused from inactive */
        if ( conn->c_conn_state == SLAP_C_INACTIVE ) {
-               memset( &conn->c_pagedresults_state, 0, sizeof( conn->c_pagedresults_state ) );
+               memset( &conn->c_pagedresults_state, 0,
+                       sizeof( conn->c_pagedresults_state ) );
        }
 
        op->o_res_ber = NULL;
@@ -1481,16 +1838,32 @@ connection_input(
         * already pending ops, let them go first.  Abandon operations
         * get exceptions to some, but not all, cases.
         */
-       if (tag != LDAP_REQ_ABANDON && conn->c_conn_state == SLAP_C_CLOSING) {
-               defer = "closing";
-       } else if (tag != LDAP_REQ_ABANDON && conn->c_writewaiter) {
-               defer = "awaiting write";
-       } else if (conn->c_n_ops_executing >= connection_pool_max/2) {
-               defer = "too many executing";
-       } else if (conn->c_conn_state == SLAP_C_BINDING) {
-               defer = "binding";
-       } else if (tag != LDAP_REQ_ABANDON && conn->c_n_ops_pending) {
-               defer = "pending operations";
+       switch( tag ){
+       default:
+               /* Abandon and Unbind are exempt from these checks */
+               if (conn->c_conn_state == SLAP_C_CLOSING) {
+                       defer = "closing";
+                       break;
+               } else if (conn->c_writewaiter) {
+                       defer = "awaiting write";
+                       break;
+               } else if (conn->c_n_ops_pending) {
+                       defer = "pending operations";
+                       break;
+               }
+               /* FALLTHRU */
+       case LDAP_REQ_ABANDON:
+               /* Unbind is exempt from these checks */
+               if (conn->c_n_ops_executing >= connection_pool_max/2) {
+                       defer = "too many executing";
+                       break;
+               } else if (conn->c_conn_state == SLAP_C_BINDING) {
+                       defer = "binding";
+                       break;
+               }
+               /* FALLTHRU */
+       case LDAP_REQ_UNBIND:
+               break;
        }
 
        if( defer ) {
@@ -1503,14 +1876,33 @@ connection_input(
                        conn->c_connid, defer, 0 );
                conn->c_n_ops_pending++;
                LDAP_STAILQ_INSERT_TAIL( &conn->c_pending_ops, op, o_next );
-               if ( conn->c_n_ops_pending > max ) {
-                       rc = -1;
-               } else {
-                       rc = 1;
-               }
+               rc = ( conn->c_n_ops_pending > max ) ? -1 : 0;
+
        } else {
                conn->c_n_ops_executing++;
+
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+               /*
+                * The first op will be processed in the same thread context,
+                * as long as there is only one op total.
+                * Subsequent ops will be submitted to the pool by
+                * calling connection_op_activate()
+                */
+               if ( cri->op == NULL ) {
+                       /* the first incoming request */
+                       connection_op_queue( op );
+                       cri->op = op;
+               } else {
+                       if ( !cri->nullop ) {
+                               cri->nullop = 1;
+                               rc = ldap_pvt_thread_pool_submit( &connection_pool,
+                                       connection_operation, (void *) cri->op );
+                       }
+                       connection_op_activate( op );
+               }
+#else
                connection_op_activate( op );
+#endif
        }
 
 #ifdef NO_THREADS
@@ -1519,8 +1911,8 @@ connection_input(
                return 1;
        }
 #endif
-       assert( conn->c_struct_state == SLAP_C_USED );
 
+       assert( conn->c_struct_state == SLAP_C_USED );
        return rc;
 }
 
@@ -1534,8 +1926,8 @@ connection_resched( Connection *conn )
                ber_socket_t    sd;
                ber_sockbuf_ctrl( conn->c_sb, LBER_SB_OPT_GET_FD, &sd );
 
-               /* us trylock to avoid possible deadlock */
-               rc = ldap_pvt_thread_mutex_trylock( &connections_mutex );
+               /* use trylock to avoid possible deadlock */
+               rc = ldap_pvt_thread_mutex_trylock( MCA_GET_CONN_MUTEX( sd ) );
 
                if( rc ) {
                        Debug( LDAP_DEBUG_TRACE,
@@ -1547,7 +1939,7 @@ connection_resched( Connection *conn )
                         * so recheck state below.
                         */
                        ldap_pvt_thread_mutex_unlock( &conn->c_mutex );
-                       ldap_pvt_thread_mutex_lock( &connections_mutex );
+                       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX ( sd ) );
                        ldap_pvt_thread_mutex_lock( &conn->c_mutex );
                }
 
@@ -1562,7 +1954,7 @@ connection_resched( Connection *conn )
                        connection_close( conn );
                }
 
-               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX( sd ) );
                return 0;
        }
 
@@ -1572,11 +1964,11 @@ connection_resched( Connection *conn )
        }
 
        while ((op = LDAP_STAILQ_FIRST( &conn->c_pending_ops )) != NULL) {
-               if ( conn->c_n_ops_executing > connection_pool_max/2 ) {
-                       break;
-               }
+               if ( conn->c_n_ops_executing > connection_pool_max/2 ) break;
+
                LDAP_STAILQ_REMOVE_HEAD( &conn->c_pending_ops, o_next );
                LDAP_STAILQ_NEXT(op, o_next) = NULL;
+
                /* pending operations should not be marked for abandonment */
                assert(!op->o_abandon);
 
@@ -1585,9 +1977,7 @@ connection_resched( Connection *conn )
 
                connection_op_activate( op );
 
-               if ( conn->c_conn_state == SLAP_C_BINDING ) {
-                       break;
-               }
+               if ( conn->c_conn_state == SLAP_C_BINDING ) break;
        }
        return 0;
 }
@@ -1597,28 +1987,108 @@ connection_init_log_prefix( Operation *op )
 {
        if ( op->o_connid == (unsigned long)(-1) ) {
                snprintf( op->o_log_prefix, sizeof( op->o_log_prefix ),
-                               "conn=-1 op=%lu", op->o_opid );
+                       "conn=-1 op=%lu", op->o_opid );
 
        } else {
                snprintf( op->o_log_prefix, sizeof( op->o_log_prefix ),
-                               "conn=%lu op=%lu", op->o_connid, op->o_opid );
+                       "conn=%lu op=%lu", op->o_connid, op->o_opid );
        }
 }
 
-static int connection_op_activate( Operation *op )
+static int connection_bind_cleanup_cb( Operation *op, SlapReply *rs )
+{
+       op->o_conn->c_sasl_bindop = NULL;
+
+       return SLAP_CB_CONTINUE;
+}
+
+static int connection_bind_cb( Operation *op, SlapReply *rs )
+{
+       slap_callback *cb = op->o_callback;
+       op->o_callback = cb->sc_next;
+
+       ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+       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 );
+
+       /* Moved here from bind.c due to ITS#4158 */
+       op->o_conn->c_sasl_bindop = NULL;
+       if ( op->orb_method == LDAP_AUTH_SASL ) {
+               if( rs->sr_err == LDAP_SUCCESS ) {
+                       ber_dupbv(&op->o_conn->c_dn, &op->orb_edn);
+                       if( !BER_BVISEMPTY( &op->orb_edn ) ) {
+                               /* edn is always normalized already */
+                               ber_dupbv( &op->o_conn->c_ndn, &op->o_conn->c_dn );
+                       }
+                       op->o_tmpfree( op->orb_edn.bv_val, op->o_tmpmemctx );
+                       BER_BVZERO( &op->orb_edn );
+                       op->o_conn->c_authmech = op->o_conn->c_sasl_bind_mech;
+                       BER_BVZERO( &op->o_conn->c_sasl_bind_mech );
+
+                       op->o_conn->c_sasl_ssf = op->orb_ssf;
+                       if( op->orb_ssf > op->o_conn->c_ssf ) {
+                               op->o_conn->c_ssf = op->orb_ssf;
+                       }
+
+                       if( !BER_BVISEMPTY( &op->o_conn->c_dn ) ) {
+                               ber_len_t max = sockbuf_max_incoming_auth;
+                               ber_sockbuf_ctrl( op->o_conn->c_sb,
+                                       LBER_SB_OPT_SET_MAX_INCOMING, &max );
+                       }
+
+                       /* log authorization identity */
+                       Statslog( LDAP_DEBUG_STATS,
+                               "%s BIND dn=\"%s\" mech=%s ssf=%d\n",
+                               op->o_log_prefix,
+                               BER_BVISNULL( &op->o_conn->c_dn ) ? "<empty>" : op->o_conn->c_dn.bv_val,
+                               op->o_conn->c_authmech.bv_val, op->orb_ssf, 0 );
+
+                       Debug( LDAP_DEBUG_TRACE,
+                               "do_bind: SASL/%s bind: dn=\"%s\" ssf=%d\n",
+                               op->o_conn->c_authmech.bv_val,
+                               BER_BVISNULL( &op->o_conn->c_dn ) ? "<empty>" : op->o_conn->c_dn.bv_val,
+                               op->orb_ssf );
+
+               } else if ( rs->sr_err != LDAP_SASL_BIND_IN_PROGRESS ) {
+                       if ( !BER_BVISNULL( &op->o_conn->c_sasl_bind_mech ) ) {
+                               free( op->o_conn->c_sasl_bind_mech.bv_val );
+                               BER_BVZERO( &op->o_conn->c_sasl_bind_mech );
+                       }
+               }
+       }
+       ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+
+       ch_free( cb );
+       op->o_callback = NULL;
+
+       return SLAP_CB_CONTINUE;
+}
+
+static void connection_op_queue( Operation *op )
 {
-       int status;
        ber_tag_t tag = op->o_tag;
 
-       if(tag == LDAP_REQ_BIND) {
+       if (tag == LDAP_REQ_BIND) {
+               slap_callback *sc = ch_calloc( 1, sizeof( slap_callback ));
+               sc->sc_response = connection_bind_cb;
+               sc->sc_cleanup = connection_bind_cleanup_cb;
+               sc->sc_next = op->o_callback;
+               op->o_callback = sc;
                op->o_conn->c_conn_state = SLAP_C_BINDING;
        }
 
        if (!op->o_dn.bv_len) {
                op->o_authz = op->o_conn->c_authz;
-               ber_dupbv( &op->o_dn, &op->o_conn->c_dn );
-               ber_dupbv( &op->o_ndn, &op->o_conn->c_ndn );
+               if ( BER_BVISNULL( &op->o_conn->c_sasl_authz_dn )) {
+                       ber_dupbv( &op->o_dn, &op->o_conn->c_dn );
+                       ber_dupbv( &op->o_ndn, &op->o_conn->c_ndn );
+               } else {
+                       ber_dupbv( &op->o_dn, &op->o_conn->c_sasl_authz_dn );
+                       ber_dupbv( &op->o_ndn, &op->o_conn->c_sasl_authz_dn );
+               }
        }
+
        op->o_authtype = op->o_conn->c_authtype;
        ber_dupbv( &op->o_authmech, &op->o_conn->c_authmech );
        
@@ -1626,8 +2096,9 @@ static int connection_op_activate( Operation *op )
                op->o_protocol = op->o_conn->c_protocol
                        ? op->o_conn->c_protocol : LDAP_VERSION3;
        }
-       if (op->o_conn->c_conn_state == SLAP_C_INACTIVE
-               && op->o_protocol > LDAP_VERSION2)
+
+       if (op->o_conn->c_conn_state == SLAP_C_INACTIVE &&
+               op->o_protocol > LDAP_VERSION2)
        {
                op->o_conn->c_conn_state = SLAP_C_ACTIVE;
        }
@@ -1636,41 +2107,79 @@ static int connection_op_activate( Operation *op )
        connection_init_log_prefix( op );
 
        LDAP_STAILQ_INSERT_TAIL( &op->o_conn->c_ops, op, o_next );
+}
 
-       status = ldap_pvt_thread_pool_submit( &connection_pool,
+static int connection_op_activate( Operation *op )
+{
+       int rc;
+
+       connection_op_queue( op );
+
+       rc = ldap_pvt_thread_pool_submit( &connection_pool,
                connection_operation, (void *) op );
 
-       if ( status != 0 ) {
+       if ( rc != 0 ) {
                Debug( LDAP_DEBUG_ANY,
-                       "ldap_pvt_thread_pool_submit: failed (%d) for conn=%lu\n",
-                       status, op->o_connid, 0 );
+                       "connection_op_activate: submit failed (%d) for conn=%lu\n",
+                       rc, op->o_connid, 0 );
                /* should move op to pending list */
        }
 
-       return status;
+       return rc;
 }
 
+#ifdef SLAP_LIGHTWEIGHT_DISPATCHER
+static int connection_write( ber_socket_t s );
+static void *connection_write_thread( void *ctx, void *arg )
+{
+       return (void *)(long)connection_write((long)arg);
+}
+
+int connection_write_activate( ber_socket_t s )
+{
+       int rc;
+
+       /*
+        * suspend reading on this file descriptor until a connection processing
+        * thread write data on it. Otherwise the listener thread will repeatedly
+        * submit the same event on it to the pool.
+        */
+       slapd_clr_write( s, 0);
+
+       rc = ldap_pvt_thread_pool_submit( &connection_pool,
+               connection_write_thread, (void *)(long)s );
+
+       if( rc != 0 ) {
+               Debug( LDAP_DEBUG_ANY,
+                       "connection_write_activate(%d): submit failed (%d)\n",
+                       (int) s, rc, 0 );
+       }
+       return rc;
+}
+
+static
+#endif
 int connection_write(ber_socket_t s)
 {
        Connection *c;
+       Operation *op;
 
        assert( connections != NULL );
 
-       ldap_pvt_thread_mutex_lock( &connections_mutex );
+       ldap_pvt_thread_mutex_lock( MCA_GET_CONN_MUTEX( s ) );
 
        c = connection_get( s );
-
-       slapd_clr_write( s, 0);
-
        if( c == NULL ) {
                Debug( LDAP_DEBUG_ANY,
                        "connection_write(%ld): no connection!\n",
                        (long)s, 0, 0 );
-               slapd_remove(s, 1, 0);
-               ldap_pvt_thread_mutex_unlock( &connections_mutex );
+               ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX( s ) );
                return -1;
        }
 
+#ifndef SLAP_LIGHTWEIGHT_DISPATCHER
+       slapd_clr_write( s, 0);
+#endif
        c->c_n_write++;
 
        Debug( LDAP_DEBUG_TRACE,
@@ -1684,8 +2193,30 @@ int connection_write(ber_socket_t s)
        if ( ber_sockbuf_ctrl( c->c_sb, LBER_SB_OPT_NEEDS_WRITE, NULL ) ) {
                slapd_set_write( s, 1 );
        }
+
+       /* If there are ops pending because of a writewaiter,
+        * start one up.
+        */
+       while ((op = LDAP_STAILQ_FIRST( &c->c_pending_ops )) != NULL) {
+               if ( !c->c_writewaiter ) break;
+               if ( c->c_n_ops_executing > connection_pool_max/2 ) break;
+
+               LDAP_STAILQ_REMOVE_HEAD( &c->c_pending_ops, o_next );
+               LDAP_STAILQ_NEXT(op, o_next) = NULL;
+
+               /* pending operations should not be marked for abandonment */
+               assert(!op->o_abandon);
+
+               c->c_n_ops_pending--;
+               c->c_n_ops_executing++;
+
+               connection_op_activate( op );
+
+               break;
+       }
+
        connection_return( c );
-       ldap_pvt_thread_mutex_unlock( &connections_mutex );
+       ldap_pvt_thread_mutex_unlock( MCA_GET_CONN_MUTEX(s) );
        return 0;
 }
 
@@ -1703,8 +2234,11 @@ connection_fake_init(
        conn->c_peer_domain = slap_empty_bv;
        conn->c_peer_name = slap_empty_bv;
 
+       memset(op, 0, OPERATION_BUFFER_SIZE);
+       op->o_hdr = (Opheader *)(op+1);
+       op->o_controls = (void **)(op->o_hdr+1);
        /* set memory context */
-       op->o_tmpmemctx = slap_sl_mem_create( SLAP_SLAB_SIZE, ctx );
+       op->o_tmpmemctx = slap_sl_mem_create(SLAP_SLAB_SIZE, SLAP_SLAB_STACK, ctx);
        op->o_tmpmfuncs = &slap_sl_mfuncs;
        op->o_threadctx = ctx;
 
@@ -1712,7 +2246,12 @@ connection_fake_init(
        op->o_connid = op->o_conn->c_connid;
        connection_init_log_prefix( op );
 
-       op->o_time = slap_get_time();
+#ifdef LDAP_SLAPI
+       slapi_int_create_object_extensions( SLAPI_X_EXT_CONNECTION, conn );
+       slapi_int_create_object_extensions( SLAPI_X_EXT_OPERATION, op );
+#endif /* LDAP_SLAPI */
+
+       slap_op_time( &op->o_time, &op->o_tincr );
 }
 
 void
@@ -1722,4 +2261,3 @@ connection_assign_nextid( Connection *conn )
        conn->c_connid = conn_nextid++;
        ldap_pvt_thread_mutex_unlock( &conn_nextid_mutex );
 }
-