Bug#11829813 UNUSED MUTEX COMMIT_THREADS_M

Analysis
--------
The pthread_mutex commit_threads_m was initiliazed but never
used. 

Fix
---
Removing the commit_threads_m mutex from the code base.

[ Approved by Marko rb#2475]

storage/innobase/handler/ha_innodb.cc

@@ -45,7 +45,6 @@ static pthread_mutex_t innobase_share_mutex;
 /** to force correct commit order in binlog */
 static pthread_mutex_t prepare_commit_mutex;
 static ulong commit_threads = 0;
-static pthread_mutex_t commit_threads_m;
 static pthread_cond_t commit_cond;
 static pthread_mutex_t commit_cond_m;
 static pthread_mutex_t analyze_mutex;
@@ -2134,7 +2133,6 @@ innobase_init(
 					(hash_get_key) innobase_get_key, 0, 0);
 	pthread_mutex_init(&innobase_share_mutex, MY_MUTEX_INIT_FAST);
 	pthread_mutex_init(&prepare_commit_mutex, MY_MUTEX_INIT_FAST);
-	pthread_mutex_init(&commit_threads_m, MY_MUTEX_INIT_FAST);
 	pthread_mutex_init(&commit_cond_m, MY_MUTEX_INIT_FAST);
 	pthread_mutex_init(&analyze_mutex, MY_MUTEX_INIT_FAST);
 	pthread_cond_init(&commit_cond, NULL);
@@ -2174,7 +2172,6 @@ innobase_end(handlerton *hton, ha_panic_function type)
 						MYF(MY_ALLOW_ZERO_PTR));
 		pthread_mutex_destroy(&innobase_share_mutex);
 		pthread_mutex_destroy(&prepare_commit_mutex);
-		pthread_mutex_destroy(&commit_threads_m);
 		pthread_mutex_destroy(&commit_cond_m);
 		pthread_mutex_destroy(&analyze_mutex);
 		pthread_cond_destroy(&commit_cond);

storage/innodb_plugin/handler/ha_innodb.cc

@@ -105,7 +105,6 @@ static pthread_mutex_t innobase_share_mutex;
 /** to force correct commit order in binlog */
 static pthread_mutex_t prepare_commit_mutex;
 static ulong commit_threads = 0;
-static pthread_mutex_t commit_threads_m;
 static pthread_cond_t commit_cond;
 static pthread_mutex_t commit_cond_m;
 static bool innodb_inited = 0;
@@ -2385,7 +2384,6 @@ innobase_change_buffering_inited_ok:
 	innobase_open_tables = hash_create(200);
 	pthread_mutex_init(&innobase_share_mutex, MY_MUTEX_INIT_FAST);
 	pthread_mutex_init(&prepare_commit_mutex, MY_MUTEX_INIT_FAST);
-	pthread_mutex_init(&commit_threads_m, MY_MUTEX_INIT_FAST);
 	pthread_mutex_init(&commit_cond_m, MY_MUTEX_INIT_FAST);
 	pthread_cond_init(&commit_cond, NULL);
 	innodb_inited= 1;
@@ -2439,7 +2437,6 @@ innobase_end(
 						MYF(MY_ALLOW_ZERO_PTR));
 		pthread_mutex_destroy(&innobase_share_mutex);
 		pthread_mutex_destroy(&prepare_commit_mutex);
-		pthread_mutex_destroy(&commit_threads_m);
 		pthread_mutex_destroy(&commit_cond_m);
 		pthread_cond_destroy(&commit_cond);
 	}