Fix some race condition during PROXYSQL RESTART

lib/MySQL_Thread.cpp

@@ -2109,7 +2109,7 @@ __run_skip_1:
 		if (idle_maintenance_thread==false) {
 			int r=rand()%(GloMTH->num_threads);
 			MySQL_Thread *thr=GloMTH->mysql_threads_idles[r].worker;
-			if (idle_mysql_sessions->len) {
+			if (shutdown==0 && thr->shudown==0 idle_mysql_sessions->len) {
 				unsigned int ims=0;
 				//spin_wrlock(&GloMTH->rwlock_idles);
 				pthread_mutex_lock(&thr->myexchange.mutex_idles);
@@ -2497,6 +2497,7 @@ __run_skip_2:
 				//spin_wrlock(&GloMTH->rwlock_resumes);
 				pthread_mutex_lock(&thr->myexchange.mutex_resumes);
 				unsigned int ims;
+				if (shutdown==0 && thr->shudown==0)
 				for (ims=0; ims<resume_mysql_sessions->len; ims++) {
 					MySQL_Session *mysess=(MySQL_Session *)resume_mysql_sessions->remove_index_fast(0);
 					thr->myexchange.resume_mysql_sessions->add(mysess);
@@ -2516,7 +2517,7 @@ __run_skip_2:
 			} else {
 				//spin_wrlock(&GloMTH->rwlock_resumes);
 				pthread_mutex_lock(&thr->myexchange.mutex_resumes);
-				if (thr->myexchange.resume_mysql_sessions->len) {
+				if (shutdown==0 && thr->shudown==0 && thr->myexchange.resume_mysql_sessions->len) {
 					//unsigned int w=rand()%(GloMTH->num_threads);
 					//w++;
 					unsigned char c=0;