/***************************************************************************** Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2017, MariaDB Corporation. 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 Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA *****************************************************************************/ /**************************************************//** @file include/que0que.h Query graph Created 5/27/1996 Heikki Tuuri *******************************************************/ #ifndef que0que_h #define que0que_h #include "univ.i" #include "data0data.h" #include "dict0types.h" #include "trx0trx.h" #include "trx0roll.h" #include "srv0srv.h" #include "usr0types.h" #include "que0types.h" #include "row0types.h" #include "pars0types.h" /** Mutex protecting the query threads. */ extern ib_mutex_t que_thr_mutex; /***********************************************************************//** Creates a query graph fork node. @return own: fork node */ que_fork_t* que_fork_create( /*============*/ que_t* graph, /*!< in: graph, if NULL then this fork node is assumed to be the graph root */ que_node_t* parent, /*!< in: parent node */ ulint fork_type, /*!< in: fork type */ mem_heap_t* heap); /*!< in: memory heap where created */ /***********************************************************************//** Gets the first thr in a fork. */ UNIV_INLINE que_thr_t* que_fork_get_first_thr( /*===================*/ que_fork_t* fork); /*!< in: query fork */ /***********************************************************************//** Gets the child node of the first thr in a fork. */ UNIV_INLINE que_node_t* que_fork_get_child( /*===============*/ que_fork_t* fork); /*!< in: query fork */ /***********************************************************************//** Sets the parent of a graph node. */ UNIV_INLINE void que_node_set_parent( /*================*/ que_node_t* node, /*!< in: graph node */ que_node_t* parent);/*!< in: parent */ /** Creates a query graph thread node. @param[in] parent parent node, i.e., a fork node @param[in] heap memory heap where created @param[in] prebuilt row prebuilt structure @return own: query thread node */ que_thr_t* que_thr_create( que_fork_t* parent, mem_heap_t* heap, row_prebuilt_t* prebuilt); /**********************************************************************//** Frees a query graph, but not the heap where it was created. Does not free explicit cursor declarations, they are freed in que_graph_free. */ void que_graph_free_recursive( /*=====================*/ que_node_t* node); /*!< in: query graph node */ /**********************************************************************//** Frees a query graph. */ void que_graph_free( /*===========*/ que_t* graph); /*!< in: query graph; we assume that the memory heap where this graph was created is private to this graph: if not, then use que_graph_free_recursive and free the heap afterwards! */ /**********************************************************************//** Stops a query thread if graph or trx is in a state requiring it. The conditions are tested in the order (1) graph, (2) trx. The lock_sys_t::mutex has to be reserved. @return TRUE if stopped */ ibool que_thr_stop( /*=========*/ que_thr_t* thr); /*!< in: query thread */ /**********************************************************************//** Moves a thread from another state to the QUE_THR_RUNNING state. Increments the n_active_thrs counters of the query graph and transaction. */ void que_thr_move_to_run_state_for_mysql( /*================================*/ que_thr_t* thr, /*!< in: an query thread */ trx_t* trx); /*!< in: transaction */ /**********************************************************************//** A patch for MySQL used to 'stop' a dummy query thread used in MySQL select, when there is no error or lock wait. */ void que_thr_stop_for_mysql_no_error( /*============================*/ que_thr_t* thr, /*!< in: query thread */ trx_t* trx); /*!< in: transaction */ /**********************************************************************//** A patch for MySQL used to 'stop' a dummy query thread used in MySQL. The query thread is stopped and made inactive, except in the case where it was put to the lock wait state in lock0lock.cc, but the lock has already been granted or the transaction chosen as a victim in deadlock resolution. */ void que_thr_stop_for_mysql( /*===================*/ que_thr_t* thr); /*!< in: query thread */ /**********************************************************************//** Run a query thread. Handles lock waits. */ void que_run_threads( /*============*/ que_thr_t* thr); /*!< in: query thread */ /**********************************************************************//** Moves a suspended query thread to the QUE_THR_RUNNING state and release a worker thread to execute it. This function should be used to end the wait state of a query thread waiting for a lock or a stored procedure completion. @return query thread instance of thread to wakeup or NULL */ que_thr_t* que_thr_end_lock_wait( /*==================*/ trx_t* trx); /*!< in: transaction in the QUE_THR_LOCK_WAIT state */ /**********************************************************************//** Starts execution of a command in a query fork. Picks a query thread which is not in the QUE_THR_RUNNING state and moves it to that state. If none can be chosen, a situation which may arise in parallelized fetches, NULL is returned. @return a query thread of the graph moved to QUE_THR_RUNNING state, or NULL; the query thread should be executed by que_run_threads by the caller */ que_thr_t* que_fork_start_command( /*===================*/ que_fork_t* fork); /*!< in: a query fork */ /***********************************************************************//** Gets the trx of a query thread. */ UNIV_INLINE trx_t* thr_get_trx( /*========*/ que_thr_t* thr); /*!< in: query thread */ /*******************************************************************//** Determines if this thread is rolling back an incomplete transaction in crash recovery. @return TRUE if thr is rolling back an incomplete transaction in crash recovery */ UNIV_INLINE ibool thr_is_recv( /*========*/ const que_thr_t* thr); /*!< in: query thread */ /***********************************************************************//** Gets the type of a graph node. */ UNIV_INLINE ulint que_node_get_type( /*==============*/ const que_node_t* node); /*!< in: graph node */ /***********************************************************************//** Gets pointer to the value data type field of a graph node. */ UNIV_INLINE dtype_t* que_node_get_data_type( /*===================*/ que_node_t* node); /*!< in: graph node */ /***********************************************************************//** Gets pointer to the value dfield of a graph node. */ UNIV_INLINE dfield_t* que_node_get_val( /*=============*/ que_node_t* node); /*!< in: graph node */ /***********************************************************************//** Gets the value buffer size of a graph node. @return val buffer size, not defined if val.data == NULL in node */ UNIV_INLINE ulint que_node_get_val_buf_size( /*======================*/ que_node_t* node); /*!< in: graph node */ /***********************************************************************//** Sets the value buffer size of a graph node. */ UNIV_INLINE void que_node_set_val_buf_size( /*======================*/ que_node_t* node, /*!< in: graph node */ ulint size); /*!< in: size */ /*********************************************************************//** Gets the next list node in a list of query graph nodes. */ UNIV_INLINE que_node_t* que_node_get_next( /*==============*/ que_node_t* node); /*!< in: node in a list */ /*********************************************************************//** Gets the parent node of a query graph node. @return parent node or NULL */ UNIV_INLINE que_node_t* que_node_get_parent( /*================*/ que_node_t* node); /*!< in: node */ /****************************************************************//** Get the first containing loop node (e.g. while_node_t or for_node_t) for the given node, or NULL if the node is not within a loop. @return containing loop node, or NULL. */ que_node_t* que_node_get_containing_loop_node( /*==============================*/ que_node_t* node); /*!< in: node */ /*********************************************************************//** Catenates a query graph node to a list of them, possible empty list. @return one-way list of nodes */ UNIV_INLINE que_node_t* que_node_list_add_last( /*===================*/ que_node_t* node_list, /*!< in: node list, or NULL */ que_node_t* node); /*!< in: node */ /************************************************************************* Get the last node from the list.*/ UNIV_INLINE que_node_t* que_node_list_get_last( /*===================*/ /* out: node last node from list.*/ que_node_t* node_list); /* in: node list, or NULL */ /*********************************************************************//** Gets a query graph node list length. @return length, for NULL list 0 */ UNIV_INLINE ulint que_node_list_get_len( /*==================*/ que_node_t* node_list); /*!< in: node list, or NULL */ /**********************************************************************//** Checks if graph, trx, or session is in a state where the query thread should be stopped. @return TRUE if should be stopped; NOTE that if the peek is made without reserving the trx_t::mutex, then another peek with the mutex reserved is necessary before deciding the actual stopping */ UNIV_INLINE ibool que_thr_peek_stop( /*==============*/ que_thr_t* thr); /*!< in: query thread */ /***********************************************************************//** Returns TRUE if the query graph is for a SELECT statement. @return TRUE if a select */ UNIV_INLINE ibool que_graph_is_select( /*================*/ que_t* graph); /*!< in: graph */ /**********************************************************************//** Prints info of an SQL query graph node. */ void que_node_print_info( /*================*/ que_node_t* node); /*!< in: query graph node */ /*********************************************************************//** Evaluate the given SQL @return error code or DB_SUCCESS */ dberr_t que_eval_sql( /*=========*/ pars_info_t* info, /*!< in: info struct, or NULL */ const char* sql, /*!< in: SQL string */ ibool reserve_dict_mutex, /*!< in: if TRUE, acquire/release dict_sys->mutex around call to pars_sql. */ trx_t* trx); /*!< in: trx */ /**********************************************************************//** Round robin scheduler. @return a query thread of the graph moved to QUE_THR_RUNNING state, or NULL; the query thread should be executed by que_run_threads by the caller */ que_thr_t* que_fork_scheduler_round_robin( /*===========================*/ que_fork_t* fork, /*!< in: a query fork */ que_thr_t* thr); /*!< in: current pos */ /** Query thread states */ enum que_thr_state_t { QUE_THR_RUNNING, QUE_THR_PROCEDURE_WAIT, /** in selects this means that the thread is at the end of its result set (or start, in case of a scroll cursor); in other statements, this means the thread has done its task */ QUE_THR_COMPLETED, QUE_THR_COMMAND_WAIT, QUE_THR_LOCK_WAIT, QUE_THR_SUSPENDED }; /** Query thread lock states */ enum que_thr_lock_t { QUE_THR_LOCK_NOLOCK, QUE_THR_LOCK_ROW, QUE_THR_LOCK_TABLE }; /** From where the cursor position is counted */ enum que_cur_t { QUE_CUR_NOT_DEFINED, QUE_CUR_START, QUE_CUR_END }; /* Query graph query thread node: the fields are protected by the trx_t::mutex with the exceptions named below */ struct que_thr_t{ que_common_t common; /*!< type: QUE_NODE_THR */ ulint magic_n; /*!< magic number to catch memory corruption */ que_node_t* child; /*!< graph child node */ que_t* graph; /*!< graph where this node belongs */ que_thr_state_t state; /*!< state of the query thread */ ibool is_active; /*!< TRUE if the thread has been set to the run state in que_thr_move_to_run_state, but not deactivated in que_thr_dec_reference_count */ /*------------------------------*/ /* The following fields are private to the OS thread executing the query thread, and are not protected by any mutex: */ que_node_t* run_node; /*!< pointer to the node where the subgraph down from this node is currently executed */ que_node_t* prev_node; /*!< pointer to the node from which the control came */ ulint resource; /*!< resource usage of the query thread thus far */ ulint lock_state; /*!< lock state of thread (table or row) */ struct srv_slot_t* slot; /* The thread slot in the wait array in srv_sys_t */ /*------------------------------*/ /* The following fields are links for the various lists that this type can be on. */ UT_LIST_NODE_T(que_thr_t) thrs; /*!< list of thread nodes of the fork node */ UT_LIST_NODE_T(que_thr_t) trx_thrs; /*!< lists of threads in wait list of the trx */ UT_LIST_NODE_T(que_thr_t) queue; /*!< list of runnable thread nodes in the server task queue */ ulint fk_cascade_depth; /*!< maximum cascading call depth supported for foreign key constraint related delete/updates */ row_prebuilt_t* prebuilt; /*!< prebuilt structure processed by the query thread */ }; #define QUE_THR_MAGIC_N 8476583 #define QUE_THR_MAGIC_FREED 123461526 /* Query graph fork node: its fields are protected by the query thread mutex */ struct que_fork_t{ que_common_t common; /*!< type: QUE_NODE_FORK */ que_t* graph; /*!< query graph of this node */ ulint fork_type; /*!< fork type */ ulint n_active_thrs; /*!< if this is the root of a graph, the number query threads that have been started in que_thr_move_to_run_state but for which que_thr_dec_refer_count has not yet been called */ trx_t* trx; /*!< transaction: this is set only in the root node */ ulint state; /*!< state of the fork node */ que_thr_t* caller; /*!< pointer to a possible calling query thread */ UT_LIST_BASE_NODE_T(que_thr_t) thrs; /*!< list of query threads */ /*------------------------------*/ /* The fields in this section are defined only in the root node */ sym_tab_t* sym_tab; /*!< symbol table of the query, generated by the parser, or NULL if the graph was created 'by hand' */ pars_info_t* info; /*!< info struct, or NULL */ /* The following cur_... fields are relevant only in a select graph */ ulint cur_end; /*!< QUE_CUR_NOT_DEFINED, QUE_CUR_START, QUE_CUR_END */ ulint cur_pos; /*!< if there are n rows in the result set, values 0 and n + 1 mean before first row, or after last row, depending on cur_end; values 1...n mean a row index */ ibool cur_on_row; /*!< TRUE if cursor is on a row, i.e., it is not before the first row or after the last row */ sel_node_t* last_sel_node; /*!< last executed select node, or NULL if none */ UT_LIST_NODE_T(que_fork_t) graphs; /*!< list of query graphs of a session or a stored procedure */ /*------------------------------*/ mem_heap_t* heap; /*!< memory heap where the fork was created */ }; /* Query fork (or graph) types */ #define QUE_FORK_SELECT_NON_SCROLL 1 /* forward-only cursor */ #define QUE_FORK_SELECT_SCROLL 2 /* scrollable cursor */ #define QUE_FORK_INSERT 3 #define QUE_FORK_UPDATE 4 #define QUE_FORK_ROLLBACK 5 /* This is really the undo graph used in rollback, no signal-sending roll_node in this graph */ #define QUE_FORK_PURGE 6 #define QUE_FORK_EXECUTE 7 #define QUE_FORK_PROCEDURE 8 #define QUE_FORK_PROCEDURE_CALL 9 #define QUE_FORK_MYSQL_INTERFACE 10 #define QUE_FORK_RECOVERY 11 /* Query fork (or graph) states */ #define QUE_FORK_ACTIVE 1 #define QUE_FORK_COMMAND_WAIT 2 #define QUE_FORK_INVALID 3 #define QUE_FORK_BEING_FREED 4 /* Flag which is ORed to control structure statement node types */ #define QUE_NODE_CONTROL_STAT 1024 /* Query graph node types */ #define QUE_NODE_LOCK 1 #define QUE_NODE_INSERT 2 #define QUE_NODE_UPDATE 4 #define QUE_NODE_CURSOR 5 #define QUE_NODE_SELECT 6 #define QUE_NODE_AGGREGATE 7 #define QUE_NODE_FORK 8 #define QUE_NODE_THR 9 #define QUE_NODE_UNDO 10 #define QUE_NODE_COMMIT 11 #define QUE_NODE_ROLLBACK 12 #define QUE_NODE_PURGE 13 #define QUE_NODE_CREATE_TABLE 14 #define QUE_NODE_CREATE_INDEX 15 #define QUE_NODE_SYMBOL 16 #define QUE_NODE_RES_WORD 17 #define QUE_NODE_FUNC 18 #define QUE_NODE_ORDER 19 #define QUE_NODE_PROC (20 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_IF (21 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_WHILE (22 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_ASSIGNMENT 23 #define QUE_NODE_FETCH 24 #define QUE_NODE_OPEN 25 #define QUE_NODE_COL_ASSIGNMENT 26 #define QUE_NODE_FOR (27 + QUE_NODE_CONTROL_STAT) #define QUE_NODE_RETURN 28 #define QUE_NODE_ROW_PRINTF 29 #define QUE_NODE_ELSIF 30 #define QUE_NODE_CALL 31 #define QUE_NODE_EXIT 32 #include "que0que.ic" #endif