fix data races

srv_last_monitor_time: make all accesses relaxed atomical

WARNING: ThreadSanitizer: data race (pid=12041)
  Write of size 8 at 0x000003949278 by thread T26 (mutexes: write M226445748578513120):
    #0 thd_destructor_proxy storage/innobase/handler/ha_innodb.cc:314:14 (mysqld+0x19b5505)

  Previous read of size 8 at 0x000003949278 by main thread:
    #0 innobase_init(void*) storage/innobase/handler/ha_innodb.cc:4180:11 (mysqld+0x1a03404)
    #1 ha_initialize_handlerton(st_plugin_int*) sql/handler.cc:522:31 (mysqld+0xc5ec73)
    #2 plugin_initialize(st_mem_root*, st_plugin_int*, int*, char**, bool) sql/sql_plugin.cc:1447:9 (mysqld+0x134908d)
    #3 plugin_init(int*, char**, int) sql/sql_plugin.cc:1729:15 (mysqld+0x13484f0)
    #4 init_server_components() sql/mysqld.cc:5345:7 (mysqld+0xbf720f)
    #5 mysqld_main(int, char**) sql/mysqld.cc:5940:7 (mysqld+0xbf107d)
    #6 main sql/main.cc:25:10 (mysqld+0xbe971b)

  Location is global 'srv_running' of size 8 at 0x000003949278 (mysqld+0x000003949278)

WARNING: ThreadSanitizer: data race (pid=27869)
  Atomic write of size 4 at 0x7b4800000c00 by thread T8:
    #0 __tsan_atomic32_exchange llvm/projects/compiler-rt/lib/tsan/rtl/tsan_interface_atomic.cc:589 (mysqld+0xbd4eac)
    #1 TTASEventMutex<GenericPolicy>::exit() storage/innobase/include/ib0mutex.h:467:7 (mysqld+0x1a8d4cb)
    #2 PolicyMutex<TTASEventMutex<GenericPolicy> >::exit() storage/innobase/include/ib0mutex.h:609:10 (mysqld+0x1a7839e)
    #3 fil_validate() storage/innobase/fil/fil0fil.cc:5535:2 (mysqld+0x1abd913)
    #4 fil_validate_skip() storage/innobase/fil/fil0fil.cc:204:9 (mysqld+0x1aba601)
    #5 fil_aio_wait(unsigned long) storage/innobase/fil/fil0fil.cc:5296:2 (mysqld+0x1abbae6)
    #6 io_handler_thread storage/innobase/srv/srv0start.cc:340:3 (mysqld+0x21abe1e)

  Previous read of size 4 at 0x7b4800000c00 by main thread (mutexes: write M1273, write M1271):
    #0 TTASEventMutex<GenericPolicy>::state() const storage/innobase/include/ib0mutex.h:530:10 (mysqld+0x21c66e2)
    #1 sync_array_detect_deadlock(sync_array_t*, sync_cell_t*, sync_cell_t*, unsigned long) storage/innobase/sync/sync0arr.cc:746:14 (mysqld+0x21c1c7a)
    #2 sync_array_wait_event(sync_array_t*, sync_cell_t*&) storage/innobase/sync/sync0arr.cc:465:6 (mysqld+0x21c1708)
    #3 TTASEventMutex<GenericPolicy>::enter(unsigned int, unsigned int, char const*, unsigned int) storage/innobase/include/ib0mutex.h:516:6 (mysqld+0x1a8c206)
    #4 PolicyMutex<TTASEventMutex<GenericPolicy> >::enter(unsigned int, unsigned int, char const*, unsigned int) storage/innobase/include/ib0mutex.h:635:10 (mysqld+0x1a782c3)
    #5 fil_mutex_enter_and_prepare_for_io(unsigned long) storage/innobase/fil/fil0fil.cc:1131:3 (mysqld+0x1a9a92e)
    #6 fil_io(IORequest const&, bool, page_id_t const&, page_size_t const&, unsigned long, unsigned long, void*, void*, bool) storage/innobase/fil/fil0fil.cc:5082:2 (mysqld+0x1ab8de2)
    #7 buf_flush_write_block_low(buf_page_t*, buf_flush_t, bool) storage/innobase/buf/buf0flu.cc:1112:3 (mysqld+0x1cb970a)
    #8 buf_flush_page(buf_pool_t*, buf_page_t*, buf_flush_t, bool) storage/innobase/buf/buf0flu.cc:1270:3 (mysqld+0x1cb7d70)
    #9 buf_flush_try_neighbors(page_id_t const&, buf_flush_t, unsigned long, unsigned long) storage/innobase/buf/buf0flu.cc:1493:9 (mysqld+0x1cc9674)
    #10 buf_flush_page_and_try_neighbors(buf_page_t*, buf_flush_t, unsigned long, unsigned long*) storage/innobase/buf/buf0flu.cc:1565:13 (mysqld+0x1cbadf3)
    #11 buf_do_flush_list_batch(buf_pool_t*, unsigned long, unsigned long) storage/innobase/buf/buf0flu.cc:1825:3 (mysqld+0x1cbbcb8)
    #12 buf_flush_batch(buf_pool_t*, buf_flush_t, unsigned long, unsigned long, flush_counters_t*) storage/innobase/buf/buf0flu.cc:1895:16 (mysqld+0x1cbb459)
    #13 buf_flush_do_batch(buf_pool_t*, buf_flush_t, unsigned long, unsigned long, flush_counters_t*) storage/innobase/buf/buf0flu.cc:2065:2 (mysqld+0x1cbcfe1)
    #14 buf_flush_lists(unsigned long, unsigned long, unsigned long*) storage/innobase/buf/buf0flu.cc:2167:8 (mysqld+0x1cbd5a3)
    #15 log_preflush_pool_modified_pages(unsigned long) storage/innobase/log/log0log.cc:1400:13 (mysqld+0x1eefc3b)
    #16 log_make_checkpoint_at(unsigned long, bool) storage/innobase/log/log0log.cc:1751:10 (mysqld+0x1eefb16)
    #17 buf_dblwr_create() storage/innobase/buf/buf0dblwr.cc:335:2 (mysqld+0x1cd2141)
    #18 innobase_start_or_create_for_mysql() storage/innobase/srv/srv0start.cc:2539:10 (mysqld+0x21b4d8e)
    #19 innobase_init(void*) storage/innobase/handler/ha_innodb.cc:4193:8 (mysqld+0x1a5e3d7)
    #20 ha_initialize_handlerton(st_plugin_int*) sql/handler.cc:522:31 (mysqld+0xc74d33)
    #21 plugin_initialize(st_mem_root*, st_plugin_int*, int*, char**, bool) sql/sql_plugin.cc:1447:9 (mysqld+0x1376d5d)
    #22 plugin_init(int*, char**, int) sql/sql_plugin.cc:1729:15 (mysqld+0x13761c0)
    #23 init_server_components() sql/mysqld.cc:5348:7 (mysqld+0xc0d0ff)
    #24 mysqld_main(int, char**) sql/mysqld.cc:5943:7 (mysqld+0xc06f9d)
    #25 main sql/main.cc:25:10 (mysqld+0xbff71b)

WARNING: ThreadSanitizer: data race (pid=29031)
  Write of size 8 at 0x0000039e48e0 by thread T15:
    #0 srv_monitor_thread storage/innobase/srv/srv0srv.cc:1699:24 (mysqld+0x21a254e)

  Previous write of size 8 at 0x0000039e48e0 by thread T14:
    #0 srv_refresh_innodb_monitor_stats() storage/innobase/srv/srv0srv.cc:1165:24 (mysqld+0x21a3124)
    #1 srv_error_monitor_thread storage/innobase/srv/srv0srv.cc:1836:3 (mysqld+0x21a2d40)

  Location is global 'srv_last_monitor_time' of size 8 at 0x0000039e48e0 (mysqld+0x0000039e48e0)

storage/innobase/handler/ha_innodb.cc

@@ -305,7 +305,7 @@ is_partition(
 
 /** Signal to shut down InnoDB (NULL if shutdown was signaled, or if
 running in innodb_read_only mode, srv_read_only_mode) */
-volatile st_my_thread_var *srv_running;
+st_my_thread_var *srv_running;
 /** Service thread that waits for the server shutdown and stops purge threads.
 Purge workers have THDs that are needed to calculate virtual columns.
 This THDs must be destroyed rather early in the server shutdown sequence.
@@ -332,12 +332,14 @@ thd_destructor_proxy(void *)
 	myvar->current_cond = &thd_destructor_cond;
 
 	mysql_mutex_lock(&thd_destructor_mutex);
-	srv_running = myvar;
+	my_atomic_storeptr_explicit(&srv_running, myvar,
+				    MY_MEMORY_ORDER_RELAXED);
 	/* wait until the server wakes the THD to abort and die */
 	while (!srv_running->abort)
 		mysql_cond_wait(&thd_destructor_cond, &thd_destructor_mutex);
 	mysql_mutex_unlock(&thd_destructor_mutex);
-	srv_running = NULL;
+	my_atomic_storeptr_explicit(&srv_running, NULL,
+				    MY_MEMORY_ORDER_RELAXED);
 
 	while (srv_fast_shutdown == 0 &&
 	       (trx_sys_any_active_transactions() ||
@@ -4333,7 +4335,8 @@ innobase_init(
 		mysql_thread_create(thd_destructor_thread_key,
 				    &thd_destructor_thread,
 				    NULL, thd_destructor_proxy, NULL);
-		while (!srv_running)
+		while (!my_atomic_loadptr_explicit(&srv_running,
+						   MY_MEMORY_ORDER_RELAXED))
 			os_thread_sleep(20);
 	}
 
@@ -4427,10 +4430,12 @@ innobase_end(handlerton*, ha_panic_function)
 		hash_table_free(innobase_open_tables);
 		innobase_open_tables = NULL;
 
-		if (!abort_loop && srv_running) {
+		st_my_thread_var* running = my_atomic_loadptr_explicit(
+			&srv_running, MY_MEMORY_ORDER_RELAXED);
+		if (!abort_loop && running) {
 			// may be UNINSTALL PLUGIN statement
-			srv_running->abort = 1;
-			mysql_cond_broadcast(srv_running->current_cond);
+			running->abort = 1;
+			mysql_cond_broadcast(running->current_cond);
 		}
 
 		if (!srv_read_only_mode) {
@@ -17764,7 +17769,9 @@ fast_shutdown_validate(
 
 	uint new_val = *reinterpret_cast<uint*>(save);
 
-	if (srv_fast_shutdown && !new_val && !srv_running) {
+	if (srv_fast_shutdown && !new_val
+	    && !my_atomic_loadptr_explicit(&srv_running,
+					   MY_MEMORY_ORDER_RELAXED)) {
 		return(1);
 	}
 

storage/innobase/include/ib0mutex.h

@@ -527,7 +527,8 @@ struct TTASEventMutex {
 	int32 state() const
 		UNIV_NOTHROW
 	{
-		return(m_lock_word);
+		return(my_atomic_load32_explicit(&m_lock_word,
+						 MY_MEMORY_ORDER_RELAXED));
 	}
 
 	/** The event that the mutex will wait in sync0arr.cc

storage/innobase/include/srv0srv.h

@@ -476,7 +476,7 @@ extern uint	srv_fast_shutdown;	/*!< If this is 1, do not do a
 
 /** Signal to shut down InnoDB (NULL if shutdown was signaled, or if
 running in innodb_read_only mode, srv_read_only_mode) */
-extern volatile st_my_thread_var *srv_running;
+extern st_my_thread_var *srv_running;
 
 extern ibool	srv_innodb_status;
 

storage/innobase/srv/srv0srv.cc

@@ -1170,7 +1170,16 @@ srv_refresh_innodb_monitor_stats(void)
 {
 	mutex_enter(&srv_innodb_monitor_mutex);
 
-	srv_last_monitor_time = time(NULL);
+	time_t current_time = time(NULL);
+
+	if (difftime(current_time, srv_last_monitor_time) <= 60) {
+		/* We referesh InnoDB Monitor values so that averages are
+		printed from at most 60 last seconds */
+		mutex_exit(&srv_innodb_monitor_mutex);
+		return;
+	}
+
+	srv_last_monitor_time = current_time;
 
 	os_aio_refresh_stats();
 
@@ -1792,6 +1801,8 @@ DECLARE_THREAD(srv_monitor_thread)(void*)
 		}
 	}
 
+	srv_refresh_innodb_monitor_stats();
+
 	if (srv_shutdown_state != SRV_SHUTDOWN_NONE) {
 		goto exit_func;
 	}
@@ -1863,13 +1874,6 @@ DECLARE_THREAD(srv_error_monitor_thread)(void*)
 		old_lsn = new_lsn;
 	}
 
-	if (difftime(time(NULL), srv_last_monitor_time) > 60) {
-		/* We referesh InnoDB Monitor values so that averages are
-		printed from at most 60 last seconds */
-
-		srv_refresh_innodb_monitor_stats();
-	}
-
 	/* Update the statistics collected for deciding LRU
 	eviction policy. */
 	buf_LRU_stat_update();
@@ -2938,7 +2942,8 @@ srv_purge_wakeup()
 
 			srv_release_threads(SRV_WORKER, n_workers);
 		}
-	} while (!srv_running
+	} while (!my_atomic_loadptr_explicit(&srv_running,
+					     MY_MEMORY_ORDER_RELAXED)
 		 && (srv_sys.n_threads_active[SRV_WORKER]
 		     || srv_sys.n_threads_active[SRV_PURGE]));
 }

storage/innobase/srv/srv0start.cc

@@ -2840,7 +2840,8 @@ srv_shutdown_bg_undo_sources()
 void
 innodb_shutdown()
 {
-	ut_ad(!srv_running);
+	ut_ad(!my_atomic_loadptr_explicit(&srv_running,
+					  MY_MEMORY_ORDER_RELAXED));
 	ut_ad(!srv_undo_sources);
 
 	switch (srv_operation) {