Hi, Is it "ok" for two threads to access the same session?
Why do I ask? I am looking at https://bugs.launchpad.net/drizzle/+bug/439719 "Drizzle crash when running random query generator" And I noticed that when drizzled crashes, there are two threads messing with the same session: The thread that crashed: Thread 1 (process 18572 local thread 0x18707): #0 0x00007fff82b231e6 in poll () #1 0x00000001001245c9 in drizzled::slot::Listen::getProtocol (this=0x1005fed90) at slot/listen.cc:274 #2 0x0000000100010e17 in main (argc=4, argv=0x7fff5fbff3b0) at drizzled.cc:1574 ... session = (Session *) 0x101892e00 ... (Go to the end of the email for full back trace) And then this thread is also using Thread 10 (process 18572 thread 0x293f): #0 0x00007fff82b416be in __semwait_signal_nocancel () #1 0x00007fff82b412f4 in nanosleep$NOCANCEL () #2 0x00007fff82b3b404 in usleep$NOCANCEL () #3 0x00007fff82b4ff77 in abort () #4 0x00007fff82b468c1 in __assert_rtn () #5 0x000000010000db1a in Diagnostics_area::set_ok_status (this=0x1018669d8, session=0x101865e00, affected_rows_arg=0, found_rows_arg=0, last_insert_id_arg=0, message_arg=0x103646580 "Rows matched: 0 Changed: 0 Warnings: 0") at diagnostics_area.cc:89 #6 0x0000000100005ce9 in Session::my_ok (this=0x101865e00, affected_rows=0, found_rows_arg=0, passed_id=0, message=0x103646580 "Rows matched: 0 Changed: 0 Warnings: 0") at session.h: 1288 #7 0x00000001001767cf in mysql_update (session=0x101865e00, table_list=0x101889f48, fiel...@0x101866ff8, valu...@0x101867298, conds=0x10188a3c8, order_num=0, order=0x0, limit=6, ignore=false) at sql_update.cc:637 #8 0x000000010000ae0a in drizzled::statement::Update::execute (this=0x1028aeff0) at statement/update.cc:50 #9 0x0000000100146e7b in mysql_execute_command (session=0x101865e00) at sql_parse.cc:934 #10 0x0000000100147070 in mysql_parse (session=0x101865e00, inBuf=0x101889e10 "UPDATE `table0_innodb_int_autoinc` SET `int_key` = 6 WHERE `enum_not_null_key` = 0 LIMIT 6", length=90, found_semicolon=0x103646e28) at sql_parse.cc:1234 #11 0x00000001001475fc in dispatch_command (command=COM_QUERY, session=0x101865e00, packet=0x10268b001 "UPDATE `table0_innodb_int_autoinc` SET `int_key` = 6 WHERE `enum_not_null_key` = 0 LIMIT 6", packet_length=90) at sql_parse.cc:210 #12 0x0000000100104819 in Session::executeStatement (this=0x101865e00) at session.cc:727 #13 0x0000000100104e99 in Session::run (this=0x101865e00) at session.cc:602 #14 0x0000000100370012 in MultiThreadScheduler::runSession (this=0x10289d4f0, session=0x101865e00) at plugin/multi_thread/multi_thread.cc:102 #15 0x000000010036ecc8 in session_thread (arg=0x101865e00) at plugin/multi_thread/multi_thread.cc:123 #16 0x00007fff82aa5e8b in _pthread_start () #17 0x00007fff82aa5d4d in thread_start () You see, both thread are using the session 0x101892e00 . Thanks -Diego ================================================ Full back trace of the thread that crashed (gdb) bt full #0 0x00007fff82b231e6 in poll () No symbol table info available. #1 0x00000001001245c9 in drizzled::slot::Listen::getProtocol (this=0x1005fed90) at slot/listen.cc:274 ready = 25769968 x = 1 retry = 4294967295 fd = -1 protocol = (class drizzled::plugin::Protocol *) 0x10183a200 error_count = 0 #2 0x0000000100010e17 in main (argc=4, argv=0x7fff5fbff3b0) at drizzled.cc:1574 plugins = (drizzled::plugin::Registry &) @0x1005fed00: { plugin_map = { _M_t = { _M_impl = { <std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, drizzled::plugin::Handle*> > >> = { <__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, drizzled::plugin::Handle*> > >> = {<No data fields>}, <No data fields>}, members of std::_Rb_tree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, drizzled::plugin::Handle*>,std::_Select1st<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, drizzled::plugin::Handle*> >,std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >,std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, drizzled::plugin::Handle*> > >::_Rb_tree_impl<std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >,false>: _M_key_compare = { <std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = { _M_color = std::_S_red, _M_parent = 0x101121720, _M_left = 0x10289c6d0, _M_right = 0x10111fbb0 }, _M_node_count = 29 } } }, function = { udf_registry = { item_map = { _M_t = { _M_impl = { <std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, const drizzled::plugin::Function*> > >> = { <__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, const drizzled::plugin::Function*> > >> = {<No data fields>}, <No data fields>}, members of std::_Rb_tree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, const drizzled::plugin::Function*>,std::_Select1st<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, const drizzled::plugin::Function*> >,std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >,std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, const drizzled::plugin::Function*> > >::_Rb_tree_impl<std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >,false>: _M_key_compare = { <std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = { _M_color = std::_S_red, _M_parent = 0x10111fc90, _M_left = 0x10289c570, _M_right = 0x10111fc40 }, _M_node_count = 42 } } }, item_set = { _M_t = { _M_impl = { <std::allocator<std::_Rb_tree_node<const drizzled::plugin::Function*> >> = { <__gnu_cxx::new_allocator<std::_Rb_tree_node<const drizzled::plugin::Function*> >> = {<No data fields>}, <No data fields>}, members of std::_Rb_tree<const drizzled::plugin::Function*,const drizzled::plugin::Function*,std::_Identity<const drizzled::plugin::Function*>,drizzled::internal::RegistryMapCompare<const drizzled::plugin::Function*>,std::allocator<const drizzled::plugin::Function*> >::_Rb_tree_impl<drizzled::internal::RegistryMapCompare<const drizzled::plugin::Function*>,false>: _M_key_compare = {<No data fields>}, _M_header = { _M_color = std::_S_red, _M_parent = 0x102899900, _M_left = 0x10289c4d0, _M_right = 0x10111fc10 }, _M_node_count = 19 } } } } }, listen = { listen_list = { <std::_Vector_base<const drizzled::plugin::Listen*,std::allocator<const drizzled::plugin::Listen*> >> = { _M_impl = { <std::allocator<const drizzled::plugin::Listen*>> = { <__gnu_cxx::new_allocator<const drizzled::plugin::Listen*>> = {<No data fields>}, <No data fields>}, members of std::_Vector_base<const drizzled::plugin::Listen*,std::allocator<const drizzled::plugin::Listen*> >::_Vector_impl: _M_start = 0x101120170, _M_finish = 0x101120178, _M_end_of_storage = 0x101120178 } }, <No data fields>}, listen_fd_list = { <std::_Vector_base<const drizzled::plugin::Listen*,std::allocator<const drizzled::plugin::Listen*> >> = { _M_impl = { <std::allocator<const drizzled::plugin::Listen*>> = { <__gnu_cxx::new_allocator<const drizzled::plugin::Listen*>> = {<No data fields>}, <No data fields>}, members of std::_Vector_base<const drizzled::plugin::Listen*,std::allocator<const drizzled::plugin::Listen*> >::_Vector_impl: _M_start = 0x10289c990, _M_finish = 0x10289c9a0, _M_end_of_storage = 0x10289c9a0 } }, <No data fields>}, fd_list = 0x10289c760, fd_count = 3, wakeup_pipe = {103, 112} } } protocol = (class drizzled::plugin::Protocol *) 0x10183a200 session = (Session *) 0x101892e00 -- Diego Medina Web Developer http://www.fmpwizard.com _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
