Data race in buf_LRU_get_free_block at buf/buf0lru.cc:408

... startup ...

SUMMARY: ThreadSanitizer: data race /test/10.5_opt_san/storage/innobase/buf/buf0lru.cc:408 in buf_LRU_get_free_block(bool)

... mysqladmin shutdown ...

SUMMARY: ThreadSanitizer: data race /test/10.5_opt_san/storage/innobase/buf/buf0lru.cc:408 in buf_LRU_get_free_block(bool)

WARNING: ThreadSanitizer: data race (pid=2636492)

  Read of size 8 at 0x55d1d35b7e68 by thread T8:

    #0 buf_LRU_get_free_block(bool) /test/10.5_opt_san/storage/innobase/buf/buf0lru.cc:408 (mariadbd+0x15cf97e)

    #1 buf_page_init_for_read /test/10.5_opt_san/storage/innobase/buf/buf0rea.cc:109 (mariadbd+0x15d0766)

    #2 buf_read_page_low /test/10.5_opt_san/storage/innobase/buf/buf0rea.cc:313 (mariadbd+0x15d208c)

    #3 buf_read_page_background(fil_space_t*, page_id_t, unsigned long, bool) /test/10.5_opt_san/storage/innobase/buf/buf0rea.cc:510 (mariadbd+0x15d208c)

    #4 buf_load /test/10.5_opt_san/storage/innobase/buf/buf0dump.cc:677 (mariadbd+0x15c2622)

    #5 buf_dump_load_func /test/10.5_opt_san/storage/innobase/buf/buf0dump.cc:758 (mariadbd+0x15c31e1)

    #6 tpool::task::execute() /test/10.5_opt_san/tpool/task.cc:52 (mariadbd+0x16f48df)

    #7 tpool::thread_pool_generic::worker_main(tpool::worker_data*) /test/10.5_opt_san/tpool/tpool_generic.cc:546 (mariadbd+0x16f1b54)

    #8 void std::__invoke_impl<void, void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*>(std::__invoke_memfun_deref, void (tpool::thread_pool_generic::*&&)(tpool::worker_data*), tpool::thread_pool_generic*&&, tpool::worker_data*&&) /usr/include/c++/9/bits/invoke.h:73 (mariadbd+0x16f2a47)

    #9 std::__invoke_result<void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*>::type std::__invoke<void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*>(void (tpool::thread_pool_generic::*&&)(tpool::worker_data*), tpool::thread_pool_generic*&&, tpool::worker_data*&&) /usr/include/c++/9/bits/invoke.h:95 (mariadbd+0x16f2a47)

    #10 void std::thread::_Invoker<std::tuple<void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*> >::_M_invoke<0ul, 1ul, 2ul>(std::_Index_tuple<0ul, 1ul, 2ul>) /usr/include/c++/9/thread:244 (mariadbd+0x16f2a47)

    #11 std::thread::_Invoker<std::tuple<void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*> >::operator()() /usr/include/c++/9/thread:251 (mariadbd+0x16f2a47)

    #12 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (tpool::thread_pool_generic::*)(tpool::worker_data*), tpool::thread_pool_generic*, tpool::worker_data*> > >::_M_run() /usr/include/c++/9/thread:195 (mariadbd+0x16f2a47)

    #13 <null> <null> (libstdc++.so.6+0xd6d83)

  Previous write of size 8 at 0x55d1d35b7e68 by main thread:

    #0 srv_mon_default_on() /test/10.5_opt_san/storage/innobase/srv/srv0mon.cc:2099 (mariadbd+0x14decc1)

    #1 innodb_init /test/10.5_opt_san/storage/innobase/handler/ha_innodb.cc:3961 (mariadbd+0x136065c)

    #2 ha_initialize_handlerton(st_plugin_int*) /test/10.5_opt_san/sql/handler.cc:645 (mariadbd+0xcf9547)

    #3 plugin_initialize /test/10.5_opt_san/sql/sql_plugin.cc:1459 (mariadbd+0x8d3f74)

    #4 plugin_init(int*, char**, int) /test/10.5_opt_san/sql/sql_plugin.cc:1751 (mariadbd+0x8d5cc3)

    #5 init_server_components /test/10.5_opt_san/sql/mysqld.cc:4913 (mariadbd+0x72043d)

    #6 mysqld_main(int, char**) /test/10.5_opt_san/sql/mysqld.cc:5496 (mariadbd+0x725bf4)

    #7 main /test/10.5_opt_san/sql/main.cc:25 (mariadbd+0x6b8455)

  Location is global 'monitor_set_tbl' of size 32 at 0x55d1d35b7e60 

  Thread T8 (tid=2636752, running) created by main thread at:

    #0 pthread_create <null> (libtsan.so.0+0x5ea99)

    #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) <null> (libstdc++.so.6+0xd7048)

    #2 tpool::thread_pool_generic::maybe_wake_or_create_thread() /test/10.5_opt_san/tpool/tpool_generic.cc:802 (mariadbd+0x16f2787)

    #3 tpool::thread_pool_generic::submit_task(tpool::task*) /test/10.5_opt_san/tpool/tpool_generic.cc:821 (mariadbd+0x16f2787)

    #4 buf_do_load_dump /test/10.5_opt_san/storage/innobase/buf/buf0dump.cc:812 (mariadbd+0x15c115c)

    #5 buf_load_at_startup() /test/10.5_opt_san/storage/innobase/buf/buf0dump.cc:806 (mariadbd+0x15c115c)

    #6 srv_start(bool) /test/10.5_opt_san/storage/innobase/srv/srv0start.cc:1927 (mariadbd+0x6752ad)

    #7 innodb_init /test/10.5_opt_san/storage/innobase/handler/ha_innodb.cc:3922 (mariadbd+0x1360400)

    #8 ha_initialize_handlerton(st_plugin_int*) /test/10.5_opt_san/sql/handler.cc:645 (mariadbd+0xcf9547)

    #9 plugin_initialize /test/10.5_opt_san/sql/sql_plugin.cc:1459 (mariadbd+0x8d3f74)

    #10 plugin_init(int*, char**, int) /test/10.5_opt_san/sql/sql_plugin.cc:1751 (mariadbd+0x8d5cc3)

    #11 init_server_components /test/10.5_opt_san/sql/mysqld.cc:4913 (mariadbd+0x72043d)

    #12 mysqld_main(int, char**) /test/10.5_opt_san/sql/mysqld.cc:5496 (mariadbd+0x725bf4)

    #13 main /test/10.5_opt_san/sql/main.cc:25 (mariadbd+0x6b8455)

SUMMARY: ThreadSanitizer: data race /test/10.5_opt_san/storage/innobase/buf/buf0lru.cc:408 in buf_LRU_get_free_block(bool)(mariadbd+0x000002b2ae68)

@param have_mutex  whether buf_pool.mutex is already being held

@return the free control block, in state BUF_BLOCK_MEMORY */

buf_block_t* buf_LRU_get_free_block(bool have_mutex)

{

  ulint   n_iterations  = 0;

  ulint   flush_failures  = 0;

  MONITOR_INC(MONITOR_LRU_GET_FREE_SEARCH);        <------------------ Here

  if (have_mutex) {

    mysql_mutex_assert_owner(&buf_pool.mutex);

    goto got_mutex;

  }

loop:

  mysql_mutex_lock(&buf_pool.mutex);

Compiled with GCC >=7.5.0 (I use GCC 9.3.0) and:

    -DWITH_TSAN=ON -DWSREP_LIB_WITH_TSAN=ON -DMUTEXTYPE=sys

Set before execution:

    export TSAN_OPTIONS=suppress_equal_stacks=1:suppress_equal_addresses=1:history_size=7:verbosity=1:exitcode=0