2979. [bug] named could deadlock during shutdown if two

"rndc stop" commands were issued at the same
			time. [RT #22108]

CHANGES

@@ -1,3 +1,7 @@
+2979.	[bug]		named could deadlock during shutdown if two
+			"rndc stop" commands were issued at the same
+			time. [RT #22108]
+
 2978.	[port]		hpux: look for <devpoll.h> [RT #21919]
 
 2977.	[bug]		'nsupdate -l' report if the session key is missing.

bin/named/control.c

@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: control.c,v 1.40 2010/08/16 22:21:06 marka Exp $ */
+/* $Id: control.c,v 1.41 2010/12/03 22:05:19 each Exp $ */
 
 /*! \file */
 
@@ -129,11 +129,16 @@ ns_control_docommand(isccc_sexpr_t *message, isc_buffer_t *text) {
 		 * isc_app_shutdown below.
 		 */
 #endif
+		/* Do not flush master files */
 		ns_server_flushonshutdown(ns_g_server, ISC_FALSE);
 		ns_os_shutdownmsg(command, text);
 		isc_app_shutdown();
 		result = ISC_R_SUCCESS;
 	} else if (command_compare(command, NS_COMMAND_STOP)) {
+		/*
+		 * "stop" is the same as "halt" except it does
+		 * flush master files.
+		 */
 #ifdef HAVE_LIBSCF
 		if (ns_smf_got_instance == 1 && ns_smf_chroot == 1) {
 			result = ns_smf_add_message(text);

lib/isc/include/isc/namespace.h

@@ -14,7 +14,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: namespace.h,v 1.7 2010/08/13 23:47:03 tbox Exp $ */
+/* $Id: namespace.h,v 1.8 2010/12/03 22:05:19 each Exp $ */
 
 #ifndef ISCAPI_NAMESPACE_H
 #define ISCAPI_NAMESPACE_H 1
@@ -129,6 +129,7 @@
 #define isc_task_create isc__task_create
 #define isc_task_attach isc__task_attach
 #define isc_task_detach isc__task_detach
+#define isc_task_exiting isc__task_exiting
 #define isc_task_send isc__task_send
 #define isc_task_sendanddetach isc__task_sendanddetach
 #define isc_task_purgerange isc__task_purgerange

lib/isc/include/isc/task.h

@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: task.h,v 1.65 2009/09/02 18:38:40 jinmei Exp $ */
+/* $Id: task.h,v 1.66 2010/12/03 22:05:19 each Exp $ */
 
 #ifndef ISC_TASK_H
 #define ISC_TASK_H 1
@@ -599,6 +599,16 @@ isc_task_getcurrenttime(isc_task_t *task, isc_stdtime_t *t);
  *\li	'*t' has the "current time".
  */
 
+isc_boolean_t
+isc__task_exiting(isc_task_t *t);
+/*%<
+ * Returns ISC_TRUE if the task is in the process of shutting down,
+ * ISC_FALSE otherwise.
+ *
+ * Requires:
+ *\li	'task' is a valid task.
+ */
+
 /*****
  ***** Task Manager.
  *****/

lib/isc/task.c

@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: task.c,v 1.111 2009/10/05 17:30:49 fdupont Exp $ */
+/* $Id: task.c,v 1.112 2010/12/03 22:05:19 each Exp $ */
 
 /*! \file
  * \author Principal Author: Bob Halley
@@ -1482,6 +1482,15 @@ isc__task_register() {
 }
 #endif
 
+isc_boolean_t
+isc__task_exiting(isc_task_t *t) {
+	isc__task_t *task = (isc__task_t *)t;
+
+	REQUIRE(VALID_TASK(task));
+	return (TASK_SHUTTINGDOWN(task));
+}
+
+
 #if defined(HAVE_LIBXML2) && defined(BIND9)
 void
 isc_taskmgr_renderxml(isc_taskmgr_t *mgr0, xmlTextWriterPtr writer) {

lib/isc/unix/socket.c

@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.c,v 1.331 2010/12/03 00:54:39 marka Exp $ */
+/* $Id: socket.c,v 1.332 2010/12/03 22:05:19 each Exp $ */
 
 /*! \file */
 
@@ -5115,6 +5115,12 @@ isc__socket_accept(isc_socket_t *sock0,
 	 * Attach to socket and to task.
 	 */
 	isc_task_attach(task, &ntask);
+	if (isc_task_exiting(ntask)) {
+		isc_task_detach(&ntask);
+		isc_event_free(ISC_EVENT_PTR(&dev));
+		UNLOCK(&sock->lock);
+		return (ISC_R_SHUTTINGDOWN);
+	}
 	nsock->references++;
 	nsock->statsindex = sock->statsindex;
 

lib/isc/win32/socket.c

@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.c,v 1.85 2010/11/18 00:59:43 tbox Exp $ */
+/* $Id: socket.c,v 1.86 2010/12/03 22:05:19 each Exp $ */
 
 /* This code uses functions which are only available on Server 2003 and
  * higher, and Windows XP and higher.
@@ -3313,6 +3313,12 @@ isc__socket_accept(isc_socket_t *sock,
 	 * Attach to socket and to task.
 	 */
 	isc_task_attach(task, &ntask);
+	if (isc_task_exiting(ntask)) {
+		isc_task_detach(&ntask);
+		isc_event_free(ISC_EVENT_PTR(&dev));
+		UNLOCK(&sock->lock);
+		return (ISC_R_SHUTTINGDOWN);
+	}
 	nsock->references++;
 
 	adev->ev_sender = ntask;