X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=servers%2Fslapd%2Fconnection.c;h=c2be214f59f3e442408da0b329610b34e6253723;hb=35c5469f53614818d0f5ea2adbfa00b699f91f15;hp=03b5624f2f583d2377a45d89c9ae3fd2a45a3f14;hpb=948fa42499308af14f95ff6af694c4301a7b6a55;p=openldap

diff --git a/servers/slapd/connection.c b/servers/slapd/connection.c
index 03b5624f2f..c2be214f59 100644
--- a/servers/slapd/connection.c
+++ b/servers/slapd/connection.c
@@ -1,7 +1,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 1998-2004 The OpenLDAP Foundation.
+ * Copyright 1998-2005 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>
@@ -41,13 +43,38 @@
 #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 );
@@ -490,9 +676,10 @@ 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 +748,7 @@ 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 +766,9 @@ 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 +785,26 @@ 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 +814,7 @@ 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 +825,7 @@ 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 +860,19 @@ 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 +882,7 @@ 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 */
@@ -722,6 +923,7 @@ static void connection_abandon( Connection *c )
 		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 );
 	}
 
@@ -733,7 +935,7 @@ 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 );
@@ -751,6 +953,7 @@ 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 );
@@ -760,7 +963,15 @@ 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;
 	}
 }
 
@@ -793,21 +1004,34 @@ 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;
 
@@ -815,15 +1039,54 @@ 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 < MCA_ARRAY_SIZE );
 
-	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)++) {
@@ -846,22 +1109,31 @@ 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
 }
 
 /*
@@ -886,10 +1158,32 @@ 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 )
 {
@@ -897,9 +1191,7 @@ 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;
@@ -917,7 +1209,7 @@ 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:
@@ -968,53 +1260,43 @@ 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:
@@ -1022,50 +1304,27 @@ 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 )
@@ -1077,42 +1336,19 @@ operations_error:
 
 	ber_set_option( op->o_ber, LBER_OPT_BER_MEMCTX, &memctx_null );
 
-#if 0	/* DELETE ME */
-	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
-#endif
-	{
-		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 );
@@ -1137,9 +1373,10 @@ 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;
 }
 
@@ -1162,18 +1399,87 @@ 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 );
@@ -1182,9 +1488,8 @@ 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;
 	}
 
@@ -1194,17 +1499,27 @@ 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;
 	}
 
@@ -1216,34 +1531,38 @@ 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;
@@ -1265,6 +1584,9 @@ 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 );
 		}
@@ -1273,8 +1595,12 @@ 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;
 		}
 	}
@@ -1284,25 +1610,29 @@ 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;
 		}
 	}
@@ -1313,7 +1643,11 @@ 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 ));
@@ -1327,14 +1661,22 @@ 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 );
 	}
@@ -1342,15 +1684,20 @@ 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;
@@ -1375,11 +1722,11 @@ 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 ) );
@@ -1388,6 +1735,7 @@ 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;
@@ -1413,16 +1761,14 @@ 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;
@@ -1441,8 +1787,9 @@ 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 );
 	}
 
@@ -1451,7 +1798,8 @@ 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;
@@ -1492,16 +1840,32 @@ 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 ) {
@@ -1514,14 +1878,33 @@ 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
@@ -1530,8 +1913,8 @@ connection_input(
 		return 1;
 	}
 #endif
-	assert( conn->c_struct_state == SLAP_C_USED );
 
+	assert( conn->c_struct_state == SLAP_C_USED );
 	return rc;
 }
 
@@ -1545,8 +1928,8 @@ 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,
@@ -1558,7 +1941,7 @@ 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 );
 		}
 
@@ -1573,7 +1956,7 @@ 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;
 	}
 
@@ -1583,11 +1966,11 @@ 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);
 
@@ -1596,9 +1979,7 @@ 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;
 }
@@ -1608,28 +1989,100 @@ 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_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_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 );
 	
@@ -1637,8 +2090,9 @@ 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;
 	}
@@ -1647,41 +2101,79 @@ static int connection_op_activate( Operation *op )
 	connection_init_log_prefix( op );
 
 	LDAP_STAILQ_INSERT_TAIL( &op->o_conn->c_ops, op, o_next );
+}
+
+static int connection_op_activate( Operation *op )
+{
+	int rc;
+
+	connection_op_queue( op );
 
-	status = ldap_pvt_thread_pool_submit( &connection_pool,
+	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,
@@ -1695,8 +2187,30 @@ 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;
 }
 
@@ -1726,7 +2240,7 @@ connection_fake_init(
 	op->o_connid = op->o_conn->c_connid;
 	connection_init_log_prefix( op );
 
-	op->o_time = slap_get_time();
+	slap_op_time( &op->o_time, &op->o_tincr );
 }
 
 void
@@ -1736,4 +2250,3 @@ connection_assign_nextid( Connection *conn )
 	conn->c_connid = conn_nextid++;
 	ldap_pvt_thread_mutex_unlock( &conn_nextid_mutex );
 }
-