From 4f74e1010e041df492698c17fc66dc6c689442b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Thu, 24 Mar 2022 13:12:54 +0100
Subject: [PATCH] Remove task exclusive mode from ns_clientmgr

The .lock, .exiting and .excl members were not using for anything else
than starting task exclusive mode, setting .exiting to true and ending
exclusive mode.

Remove all the stray members and dead code eliminating the task
exclusive mode use from ns_clientmgr.
---
 lib/ns/client.c            | 34 ++--------------------------------
 lib/ns/include/ns/client.h |  5 -----
 2 files changed, 2 insertions(+), 37 deletions(-)

diff --git a/lib/ns/client.c b/lib/ns/client.c
index 7fa7386bba..5a9bfd85c5 100644
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -2406,13 +2406,8 @@ clientmgr_destroy(ns_clientmgr_t *manager) {
 
 	dns_aclenv_detach(&manager->aclenv);
 
-	isc_mutex_destroy(&manager->lock);
 	isc_mutex_destroy(&manager->reclock);
 
-	if (manager->excl != NULL) {
-		isc_task_detach(&manager->excl);
-	}
-
 	isc_task_detach(&manager->task);
 	ns_server_detach(&manager->sctx);
 
@@ -2433,13 +2428,6 @@ ns_clientmgr_create(ns_server_t *sctx, isc_taskmgr_t *taskmgr,
 	manager = isc_mem_get(mctx, sizeof(*manager));
 	*manager = (ns_clientmgr_t){ .magic = 0, .mctx = mctx };
 
-	result = isc_taskmgr_excltask(taskmgr, &manager->excl);
-	if (result != ISC_R_SUCCESS) {
-		isc_mem_put(mctx, manager, sizeof(*manager));
-		return (result);
-	}
-
-	isc_mutex_init(&manager->lock);
 	isc_mutex_init(&manager->reclock);
 
 	manager->taskmgr = taskmgr;
@@ -2448,7 +2436,6 @@ ns_clientmgr_create(ns_server_t *sctx, isc_taskmgr_t *taskmgr,
 
 	dns_aclenv_attach(aclenv, &manager->aclenv);
 
-	manager->exiting = false;
 	result = isc_task_create_bound(manager->taskmgr, 20, &manager->task,
 				       manager->tid);
 	RUNTIME_CHECK(result == ISC_R_SUCCESS);
@@ -2471,33 +2458,16 @@ ns_clientmgr_create(ns_server_t *sctx, isc_taskmgr_t *taskmgr,
 
 void
 ns_clientmgr_destroy(ns_clientmgr_t **managerp) {
-	isc_result_t result;
 	ns_clientmgr_t *manager;
-	bool unlock = false;
 
 	REQUIRE(managerp != NULL);
+	REQUIRE(VALID_MANAGER(*managerp));
+
 	manager = *managerp;
 	*managerp = NULL;
-	REQUIRE(VALID_MANAGER(manager));
 
 	MTRACE("destroy");
 
-	/*
-	 * Check for success because we may already be task-exclusive
-	 * at this point.  Only if we succeed at obtaining an exclusive
-	 * lock now will we need to relinquish it later.
-	 */
-	result = isc_task_beginexclusive(manager->excl);
-	if (result == ISC_R_SUCCESS) {
-		unlock = true;
-	}
-
-	manager->exiting = true;
-
-	if (unlock) {
-		isc_task_endexclusive(manager->excl);
-	}
-
 	if (isc_refcount_decrement(&manager->references) == 1) {
 		clientmgr_destroy(manager);
 	}
diff --git a/lib/ns/include/ns/client.h b/lib/ns/include/ns/client.h
index e26f14ff9d..71c223847b 100644
--- a/lib/ns/include/ns/client.h
+++ b/lib/ns/include/ns/client.h
@@ -147,7 +147,6 @@ struct ns_clientmgr {
 	ns_server_t    *sctx;
 	isc_taskmgr_t  *taskmgr;
 	isc_timermgr_t *timermgr;
-	isc_task_t	   *excl;
 	isc_refcount_t	references;
 	int		tid;
 
@@ -156,10 +155,6 @@ struct ns_clientmgr {
 
 	dns_aclenv_t *aclenv;
 
-	/* Lock covers manager state. */
-	isc_mutex_t lock;
-	bool	    exiting;
-
 	/* Lock covers the recursing list */
 	isc_mutex_t   reclock;
 	client_list_t recursing; /*%< Recursing clients */