Ticket #48178 add config param to enable nunc-stans

https://fedorahosted.org/389/ticket/48178
Reviewed by: nhosoi (Thanks!)
Branch: master
Fix Description: If nsslapd-enable-nunc-stans: on, the server will use
nunc-stans as the event framework.  NOTE: You still have to build the
server with configure --enable-nunc-stans in order to be able to set
nsslapd-enable-nunc-stans: on.  By default, the value is off.
Platforms tested: Fedora 20
Flag Day: no
Doc impact: no

ldap/servers/slapd/connection.c

@@ -282,6 +282,7 @@ connection_cleanup(Connection *conn)
 		ns_enable_listeners();
 	}
 #ifdef ENABLE_NUNC_STANS
+	/* even if !config_get_enable_nunc_stans, it is ok to set to 0 here */
 	conn->c_ns_close_jobs = 0;
 #endif
 }
@@ -2357,10 +2358,12 @@ connection_threadmain()
 	int replication_connection = 0; /* If this connection is from a replication supplier, we want to ensure that operation processing is serialized */
 	int doshutdown = 0;
 	int maxthreads = 0;
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
+	int enable_nunc_stans = 0;
 	long bypasspollcnt = 0;
-#endif
 
+#ifdef ENABLE_NUNC_STANS
+	enable_nunc_stans = config_get_enable_nunc_stans();
+#endif
 #if defined( OSF1 ) || defined( hpux )
 	/* Arrange to ignore SIGPIPE signals. */
 	SIGNAL( SIGPIPE, SIG_IGN );
@@ -2552,8 +2555,7 @@ connection_threadmain()
  * when using nunc-stans - it is supposed to be an optimization but turns out
  * to not be the opposite with nunc-stans
  */
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
-			} else { /* more data in conn - just put back on work_q - bypass poll */
+			} else if (!enable_nunc_stans) { /* more data in conn - just put back on work_q - bypass poll */
 				bypasspollcnt++;
 				PR_Lock(conn->c_mutex);
 				/* don't do this if it would put us over the max threads per conn */
@@ -2571,7 +2573,6 @@ connection_threadmain()
 					conn->c_maxthreadsblocked++;
 				}
 				PR_Unlock(conn->c_mutex);
-#endif
 			}
 		}
 

ldap/servers/slapd/conntable.c

@@ -212,6 +212,7 @@ connection_table_get_connection(Connection_Table *ct, int sd)
 		 */
 		connection_cleanup(c);
 #ifdef ENABLE_NUNC_STANS
+		/* NOTE - ok to do this here even if enable_nunc_stans is off */
 		c->c_ct = ct; /* pointer to connection table that owns this connection */
 #endif
     }

ldap/servers/slapd/daemon.c

@@ -119,12 +119,10 @@ short	slapd_housekeeping_timer = 10;
 /* Do we support timeout on socket send() ? */
 int have_send_timeouts = 0;
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 PRFileDesc*		signalpipe[2];
 static int writesignalpipe = SLAPD_INVALID_SOCKET;
 static int readsignalpipe = SLAPD_INVALID_SOCKET;
 #define FDS_SIGNAL_PIPE 0
-#endif
 
 static PRThread *disk_thread_p = NULL;
 static PRCondVar *diskmon_cvar = NULL;
@@ -148,6 +146,8 @@ typedef struct listener_info {
 static int listeners = 0; /* number of listener sockets */
 static listener_info *listener_idxs = NULL; /* array of indexes of listener sockets in the ct->fd array */
 
+static int enable_nunc_stans = 0; /* if nunc-stans is set to enabled, set to 1 in slapd_daemon */
+
 #define SLAPD_POLL_LISTEN_READY(xxflagsxx) (xxflagsxx & PR_POLL_READ)
 
 static int get_configured_connection_table_size();
@@ -177,9 +177,7 @@ static void* catch_signals();
 HANDLE  hServDoneEvent = NULL;
 #endif
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 static int createsignalpipe( void );
-#endif
 
 #if defined( _WIN32 )
 /* Set an event to hook the NT Service termination */
@@ -395,14 +393,13 @@ static void set_timeval_ms(struct timeval *t, int ms);
 static int handle_new_connection(Connection_Table *ct, int tcps, PRFileDesc *pr_acceptfd, int secure, int local, Connection **newconn );
 #ifdef ENABLE_NUNC_STANS
 static void ns_handle_new_connection(struct ns_job_t *job);
-#else
+#endif
 static void handle_pr_read_ready(Connection_Table *ct, PRIntn num_poll);
 #ifdef _WIN32
 static int clear_signal(fd_set *readfdset);
 #else
 static int clear_signal(struct POLL_STRUCT *fds);
 #endif
-#endif
 #ifdef _WIN32
 static void unfurl_banners(Connection_Table *ct,daemon_ports_t *ports, int n_tcps, PRFileDesc *s_tcps);
 #else
@@ -934,7 +931,6 @@ disk_monitoring_thread(void *nothing)
     }
 }
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 static void
 handle_listeners(Connection_Table *ct)
 {
@@ -958,7 +954,6 @@ handle_listeners(Connection_Table *ct)
 	}
 	return;
 }
-#endif /* !ENABLE_NUNC_STANS */
 
 /*
  * Convert any pre-existing DES passwords to AES.
@@ -1224,6 +1219,9 @@ void
 ns_enable_listeners()
 {
 #ifdef ENABLE_NUNC_STANS
+	if (!enable_nunc_stans) {
+		return;
+	}
 	int num_enabled = 0;
 	listener_info *listener;
 	while ((listener = (listener_info *)PR_StackPop(ns_disabled_listeners))) {
@@ -1282,7 +1280,7 @@ nunc_stans_free(void *ptr)
 {
 	slapi_ch_free((void **)&ptr);
 }
-#endif
+#endif /* ENABLE_NUNC_STANS */
 
 void slapd_daemon( daemon_ports_t *ports )
 {
@@ -1306,9 +1304,7 @@ void slapd_daemon( daemon_ports_t *ports )
 	PRFileDesc **fdesp = NULL; 
 #endif
 	PRIntn num_poll = 0;
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 	PRIntervalTime pr_timeout = PR_MillisecondsToInterval(slapd_wakeup_timer);
-#endif
 	PRThread *time_thread_p;
 	int threads;
 	int in_referral_mode = config_check_referral_mode();
@@ -1319,6 +1315,10 @@ void slapd_daemon( daemon_ports_t *ports )
 	int connection_table_size = get_configured_connection_table_size();
 	the_connection_table= connection_table_new(connection_table_size);
 
+#ifdef ENABLE_NUNC_STANS
+	enable_nunc_stans = config_get_enable_nunc_stans();
+#endif
+
 #ifdef RESOLVER_NEEDS_LOW_FILE_DESCRIPTORS
 	/*
 	 * Some DNS resolver implementations, such as the one built into
@@ -1342,10 +1342,10 @@ void slapd_daemon( daemon_ports_t *ports )
 	i_unix = ports->i_socket;
 #endif /* ENABLE_LDAPI */
 #endif
-	
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
-	createsignalpipe();
-#endif
+
+	if (!enable_nunc_stans) {
+		createsignalpipe();
+	}
 
 	init_shutdown_detect();
 
@@ -1494,7 +1494,9 @@ void slapd_daemon( daemon_ports_t *ports )
 #endif
 	listener_idxs = (listener_info *)slapi_ch_calloc(listeners, sizeof(*listener_idxs));
 #ifdef ENABLE_NUNC_STANS
-	ns_disabled_listeners = PR_CreateStack("disabled_listeners");
+	if (enable_nunc_stans) {
+		ns_disabled_listeners = PR_CreateStack("disabled_listeners");
+	}
 #endif
 	/*
 	 * Convert old DES encoded passwords to AES
@@ -1502,7 +1504,7 @@ void slapd_daemon( daemon_ports_t *ports )
 	convert_pbe_des_to_aes();
 
 #ifdef ENABLE_NUNC_STANS
-	if (!g_get_shutdown()) {
+	if (enable_nunc_stans && !g_get_shutdown()) {
 		int ii;
 		PRInt32 maxthreads = 3;
 		if (getenv("MAX_THREADS")) {
@@ -1536,7 +1538,7 @@ void slapd_daemon( daemon_ports_t *ports )
 
 		}
 	}
-#endif
+#endif /* ENABLE_NUNC_STANS */
 	/* Now we write the pid file, indicating that the server is finally and listening for connections */
 	write_pid_file();
 
@@ -1544,14 +1546,14 @@ void slapd_daemon( daemon_ports_t *ports )
 	unfurl_banners(the_connection_table,ports,n_tcps,s_tcps,i_unix);
 
 #ifdef ENABLE_NUNC_STANS
-	if (ns_thrpool_wait(tp)) {
+	if (enable_nunc_stans && ns_thrpool_wait(tp)) {
 		LDAPDebug( LDAP_DEBUG_ANY,
 			   "ns_thrpool_wait failed errno %d (%s)\n", errno,
 			   slapd_system_strerror(errno), 0 );
 	}
-
-#else	/* The meat of the operation is in a loop on a call to select */
-	while(!g_get_shutdown())
+#endif
+	/* The meat of the operation is in a loop on a call to select */
+	while(!enable_nunc_stans && !g_get_shutdown())
 	{
 #ifdef _WIN32
 		fd_set			readfds;
@@ -1614,7 +1616,6 @@ void slapd_daemon( daemon_ports_t *ports )
 			break;
 		}
 	}
-#endif /* ENABLE_NUNC_STANS */
 	/* We get here when the server is shutting down */
 	/* Do what we have to do before death */
 
@@ -1688,36 +1689,36 @@ void slapd_daemon( daemon_ports_t *ports )
 
 	threads = g_get_active_threadcnt();
 	while ( threads > 0 ) {
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
-		PRPollDesc xpd;
-		char x;
-		int spe = 0;
-
-		/* try to read from the signal pipe, in case threads are
-		 * blocked on it. */
-		xpd.fd = signalpipe[0];
-		xpd.in_flags = PR_POLL_READ;
-		xpd.out_flags = 0;
-		spe = PR_Poll(&xpd, 1, PR_INTERVAL_NO_WAIT);
-		if (spe > 0) {
-		    spe = PR_Read(signalpipe[0], &x, 1);
-		    if (spe < 0) {
-		        PRErrorCode prerr = PR_GetError();
-				LDAPDebug( LDAP_DEBUG_ANY, "listener could not clear signal pipe, " 
+		if (!enable_nunc_stans) {
+			PRPollDesc xpd;
+			char x;
+			int spe = 0;
+
+			/* try to read from the signal pipe, in case threads are
+			 * blocked on it. */
+			xpd.fd = signalpipe[0];
+			xpd.in_flags = PR_POLL_READ;
+			xpd.out_flags = 0;
+			spe = PR_Poll(&xpd, 1, PR_INTERVAL_NO_WAIT);
+			if (spe > 0) {
+				spe = PR_Read(signalpipe[0], &x, 1);
+				if (spe < 0) {
+					PRErrorCode prerr = PR_GetError();
+					LDAPDebug( LDAP_DEBUG_ANY, "listener could not clear signal pipe, "
+							SLAPI_COMPONENT_NAME_NSPR " error %d (%s)\n",
+							prerr, slapd_system_strerror(prerr), 0 );
+					break;
+				}
+			} else if (spe == -1) {
+				PRErrorCode prerr = PR_GetError();
+				LDAPDebug( LDAP_DEBUG_ANY, "PR_Poll() failed, "
 						SLAPI_COMPONENT_NAME_NSPR " error %d (%s)\n",
 						prerr, slapd_system_strerror(prerr), 0 );
-			break;
-		    }
-		} else if (spe == -1) {
-		    PRErrorCode prerr = PR_GetError();
-		    LDAPDebug( LDAP_DEBUG_ANY, "PR_Poll() failed, "
-					SLAPI_COMPONENT_NAME_NSPR " error %d (%s)\n",
-					prerr, slapd_system_strerror(prerr), 0 );
-		    break;
-		} else {
-		    /* no data */
+				break;
+			} else {
+				/* no data */
+			}
 		}
-#endif
 		DS_Sleep(PR_INTERVAL_NO_WAIT);
 		if ( threads != g_get_active_threadcnt() )  {
 			LDAPDebug( LDAP_DEBUG_TRACE,
@@ -1762,7 +1763,9 @@ void slapd_daemon( daemon_ports_t *ports )
 	connection_table_free(the_connection_table);
 	the_connection_table= NULL;
 #ifdef ENABLE_NUNC_STANS
-	ns_thrpool_destroy(tp);
+	if (enable_nunc_stans) {
+		ns_thrpool_destroy(tp);
+	}
 #endif
 	be_cleanupall ();
 	connection_post_shutdown_cleanup();
@@ -1789,7 +1792,9 @@ void slapd_daemon( daemon_ports_t *ports )
 
 int signal_listner()
 {
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
+	if (enable_nunc_stans) {
+		return( 0 );
+	}
 	/* Replaces previous macro---called to bump the thread out of select */
 #if defined( _WIN32 )
 	if ( PR_Write( signalpipe[1], "", 1) != 1 ) {
@@ -1810,18 +1815,19 @@ int signal_listner()
 				"listener could not write to signal pipe %d\n",
 				errno, 0, 0 );
 	}
-#endif
 #endif
 	return( 0 );
 }
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 #ifdef _WIN32
 static int clear_signal(fd_set *readfdset)
 #else
 static int clear_signal(struct POLL_STRUCT *fds)
 #endif
 {
+	if (enable_nunc_stans) {
+		return 0;
+	}
 #ifdef _WIN32
 	if ( FD_ISSET(readsignalpipe, readfdset)) {
 #else
@@ -1844,7 +1850,6 @@ static int clear_signal(struct POLL_STRUCT *fds)
 	} 
 	return 0;
 }
-#endif /* !ENABLE_NUNC_STANS */
 
 #ifdef _WIN32
 static void set_timeval_ms(struct timeval *t, int ms)
@@ -1989,18 +1994,18 @@ setup_pr_read_pds(Connection_Table *ct, PRFileDesc **n_tcps, PRFileDesc **s_tcps
 			ct->c[i].c_fdi = SLAPD_INVALID_SOCKET_INDEX;
 		}
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
-		/* The fds entry for the signalpipe is always FDS_SIGNAL_PIPE (== 0) */
-		count = FDS_SIGNAL_PIPE;
+		if (!enable_nunc_stans) {
+			/* The fds entry for the signalpipe is always FDS_SIGNAL_PIPE (== 0) */
+			count = FDS_SIGNAL_PIPE;
 #if !defined(_WIN32)
-		ct->fd[count].fd = signalpipe[0];
-		ct->fd[count].in_flags = SLAPD_POLL_FLAGS;
-		ct->fd[count].out_flags = 0;
+			ct->fd[count].fd = signalpipe[0];
+			ct->fd[count].in_flags = SLAPD_POLL_FLAGS;
+			ct->fd[count].out_flags = 0;
 #else
-		ct->fd[count].fd = NULL;
-#endif
-		count++;
+			ct->fd[count].fd = NULL;
 #endif
+			count++;
+		}
 		/* The fds entry for n_tcps starts with n_tcps and less than n_tcpe */
 		ct->n_tcps = count;
 		if (n_tcps != NULL && accept_new_connections)
@@ -2262,7 +2267,6 @@ handle_read_ready(Connection_Table *ct, fd_set *readfds)
 #endif   /* _WIN32 */
 
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 static void
 handle_pr_read_ready(Connection_Table *ct, PRIntn num_poll)
 {
@@ -2418,7 +2422,6 @@ handle_pr_read_ready(Connection_Table *ct, PRIntn num_poll)
 	}
 #endif
 }
-#endif /* !ENABLE_NUNC_STANS */
 
 #ifdef ENABLE_NUNC_STANS
 #define CONN_NEEDS_CLOSING(c) (c->c_flags & CONN_FLAG_CLOSING) || (c->c_sd == SLAPD_INVALID_SOCKET)
@@ -2478,6 +2481,10 @@ ns_connection_post_io_or_closing(Connection *conn)
 #ifdef ENABLE_NUNC_STANS
 	struct timeval tv;
 
+	if (!enable_nunc_stans) {
+		return;
+	}
+
 	if (CONN_NEEDS_CLOSING(conn)) {
 		/* there should only ever be 0 or 1 active closure jobs */
 		PR_ASSERT((conn->c_ns_close_jobs == 0) || (conn->c_ns_close_jobs == 1));
@@ -3386,10 +3393,10 @@ static int init_shutdown_detect()
 	(void) SIGNAL( SIGUSR1, slapd_do_nothing );
 	(void) SIGNAL( SIGUSR2, set_shutdown );
 #endif
-#ifndef ENABLE_NUNC_STANS
-	(void) SIGNAL( SIGTERM, set_shutdown );
-	(void) SIGNAL( SIGHUP,  set_shutdown );
-#endif
+	if (!enable_nunc_stans) {
+		(void) SIGNAL( SIGTERM, set_shutdown );
+		(void) SIGNAL( SIGHUP,  set_shutdown );
+	}
 #endif /* _WIN32 */
 	return 0;
 }
@@ -3984,10 +3991,12 @@ netaddr2string(const PRNetAddr *addr, char *addrbuf, size_t addrbuflen)
 }
 
 
-#if !defined(ENABLE_NUNC_STANS) || ENABLE_NUNC_STANS == 0
 static int
 createsignalpipe( void )
 {
+	if (enable_nunc_stans) {
+		return( 0 );
+	}
 #if defined( _WIN32 )
 	if ( PR_NewTCPSocketPair(&signalpipe[0])) {
 		PRErrorCode prerr = PR_GetError();
@@ -4019,7 +4028,6 @@ createsignalpipe( void )
 #endif
 	return( 0 );
 } 
-#endif
 
 
 #ifdef HPUX10

ldap/servers/slapd/libglobs.c

@@ -274,6 +274,9 @@ slapi_onoff_t init_ignore_time_skew;
 slapi_onoff_t init_dynamic_plugins;
 slapi_onoff_t init_cn_uses_dn_syntax_in_dns;
 slapi_onoff_t init_global_backend_local;
+#ifdef ENABLE_NUNC_STANS
+slapi_onoff_t init_enable_nunc_stans;
+#endif
 #if defined (LINUX)
 slapi_int_t init_malloc_mxfast;
 slapi_int_t init_malloc_trim_threshold;
@@ -1127,7 +1130,13 @@ static struct config_get_and_set {
 	{CONFIG_GLOBAL_BACKEND_LOCK, config_set_global_backend_lock,
 		NULL, 0,
 		(void**)&global_slapdFrontendConfig.global_backend_lock,
-		CONFIG_ON_OFF, (ConfigGetFunc)config_get_global_backend_lock, &init_global_backend_local}	
+		CONFIG_ON_OFF, (ConfigGetFunc)config_get_global_backend_lock, &init_global_backend_local}
+#ifdef ENABLE_NUNC_STANS
+	,{CONFIG_ENABLE_NUNC_STANS, config_set_enable_nunc_stans,
+		NULL, 0,
+		(void**)&global_slapdFrontendConfig.enable_nunc_stans,
+		CONFIG_ON_OFF, (ConfigGetFunc)config_get_enable_nunc_stans, &init_enable_nunc_stans}
+#endif
 #ifdef MEMPOOL_EXPERIMENTAL
 	,{CONFIG_MEMPOOL_SWITCH_ATTRIBUTE, config_set_mempool_switch,
 		NULL, 0,
@@ -1576,6 +1585,9 @@ FrontendConfig_init () {
   init_dynamic_plugins = cfg->dynamic_plugins = LDAP_OFF;
   init_cn_uses_dn_syntax_in_dns = cfg->cn_uses_dn_syntax_in_dns = LDAP_OFF;
   init_global_backend_local = LDAP_OFF;
+#ifdef ENABLE_NUNC_STANS
+  init_enable_nunc_stans = cfg->enable_nunc_stans = LDAP_OFF;
+#endif
 #if defined(LINUX)
   init_malloc_mxfast = cfg->malloc_mxfast = DEFAULT_MALLOC_UNSET;
   init_malloc_trim_threshold = cfg->malloc_trim_threshold = DEFAULT_MALLOC_UNSET;
@@ -7400,6 +7412,33 @@ config_get_listen_backlog_size()
   return retVal; 
 }
 
+#ifdef ENABLE_NUNC_STANS
+int
+config_get_enable_nunc_stans()
+{
+    int retVal;
+    slapdFrontendConfig_t *slapdFrontendConfig = getFrontendConfig();
+    CFG_LOCK_READ(slapdFrontendConfig);
+    retVal = slapdFrontendConfig->enable_nunc_stans;
+    CFG_UNLOCK_READ(slapdFrontendConfig);
+
+    return retVal;
+}
+
+int
+config_set_enable_nunc_stans( const char *attrname, char *value,
+                              char *errorbuf, int apply )
+{
+    int retVal = LDAP_SUCCESS;
+    slapdFrontendConfig_t *slapdFrontendConfig = getFrontendConfig();
+
+    retVal = config_set_onoff(attrname, value,
+                              &(slapdFrontendConfig->enable_nunc_stans),
+                              errorbuf, apply);
+    return retVal;
+}
+#endif
+
 static char *
 config_initvalue_to_onoff(struct config_get_and_set *cgas, char *initvalbuf, size_t initvalbufsize)
 {

ldap/servers/slapd/proto-slap.h

@@ -597,6 +597,10 @@ int config_set_dynamic_plugins(const char *attrname, char *value, char *errorbuf
 int config_get_dynamic_plugins();
 int config_set_cn_uses_dn_syntax_in_dns(const char *attrname, char *value, char *errorbuf, int apply);
 int config_get_cn_uses_dn_syntax_in_dns();
+#ifdef ENABLE_NUNC_STANS
+int config_get_enable_nunc_stans(void);
+int config_set_enable_nunc_stans(const char *attrname, char *value, char *errorbuf, int apply);
+#endif
 
 PLHashNumber hashNocaseString(const void *key);
 PRIntn hashNocaseCompare(const void *v1, const void *v2);

ldap/servers/slapd/slap.h

@@ -2126,7 +2126,9 @@ typedef struct _slapdEntryPoints {
 #define CONFIG_PLUGIN_BINDDN_TRACKING_ATTRIBUTE "nsslapd-plugin-binddn-tracking"
 #define CONFIG_MODDN_ACI_ATTRIBUTE "nsslapd-moddn-aci"
 #define CONFIG_GLOBAL_BACKEND_LOCK "nsslapd-global-backend-lock"
-
+#ifdef ENABLE_NUNC_STANS
+#define CONFIG_ENABLE_NUNC_STANS "nsslapd-enable-nunc-stans"
+#endif
 #define CONFIG_CONFIG_ATTRIBUTE "nsslapd-config"
 #define CONFIG_INSTDIR_ATTRIBUTE "nsslapd-instancedir"
 #define CONFIG_SCHEMADIR_ATTRIBUTE "nsslapd-schemadir"
@@ -2433,6 +2435,9 @@ typedef struct _slapdFrontendConfig {
   slapi_onoff_t dynamic_plugins; /* allow plugins to be dynamically enabled/disabled */
   slapi_onoff_t cn_uses_dn_syntax_in_dns; /* indicates the cn value in dns has dn syntax */
   slapi_onoff_t global_backend_lock;
+#ifdef ENABLE_NUNC_STANS
+  slapi_onoff_t enable_nunc_stans;
+#endif
 #if defined(LINUX)
   int malloc_mxfast;            /* mallopt M_MXFAST */
   int malloc_trim_threshold;    /* mallopt M_TRIM_THRESHOLD */