Bug #25167032 CRASH WHEN ASSIGNING MY_ERRNO - MISSING

		MY_THREAD_INIT IN BACKGROUND THREAD

Description:
===========
Add my_thread_init() and my_thread_exit() for background threads which
initializes and frees the st_my_thread_var structure.

Reviewed-by: Jimmy Yang<jimmy.yang@oracle.com>
RB: 15003

storage/innobase/srv/srv0srv.c

 /*****************************************************************************
 
-Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
 
@@ -2767,6 +2767,7 @@ srv_master_thread(
 	ulint		i;
 	ib_time_t	last_print_time;
 
+	my_thread_init();
 #ifdef UNIV_DEBUG_THREAD_CREATION
 	fprintf(stderr, "Master thread starts, id %lu\n",
 		os_thread_pf(os_thread_get_curr_id()));
@@ -3222,6 +3223,7 @@ srv_master_thread(
 	os_event_wait(slot->event);
 
 	if (srv_shutdown_state == SRV_SHUTDOWN_EXIT_THREADS) {
+		my_thread_end();
 		os_thread_exit(NULL);
 	}
 
@@ -3245,6 +3247,7 @@ srv_purge_thread(
 	ulint		retries = 0;
 	ulint		n_total_purged = ULINT_UNDEFINED;
 
+	my_thread_init();
 	ut_a(srv_n_purge_threads == 1);
 
 #ifdef UNIV_PFS_THREAD
@@ -3329,6 +3332,8 @@ srv_purge_thread(
 		os_thread_pf(os_thread_get_curr_id()));
 #endif /* UNIV_DEBUG_THREAD_CREATION */
 
+	my_thread_end();
+
 	/* We count the number of threads in os_thread_exit(). A created
 	thread should always use that to exit and not use return() to exit. */
 	os_thread_exit(NULL);

storage/innobase/trx/trx0roll.c

 /*****************************************************************************
 
 Copyright (c) 1996, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 2017, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -610,12 +611,15 @@ trx_rollback_or_clean_all_recovered(
 			/*!< in: a dummy parameter required by
 			os_thread_create */
 {
+	my_thread_init();
+
 #ifdef UNIV_PFS_THREAD
 	pfs_register_thread(trx_rollback_clean_thread_key);
 #endif /* UNIV_PFS_THREAD */
 
 	trx_rollback_or_clean_recovered(TRUE);
 
+	my_thread_end();
 	/* We count the number of threads in os_thread_exit(). A created
 	thread should always use that to exit and not use return() to exit. */