path: root/innobase/include/que0que.h

/******************************************************
Query graph

(c) 1996 Innobase Oy

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 "srv0srv.h"
#include "usr0types.h"
#include "que0types.h"
#include "row0types.h"
#include "pars0types.h"

/* If the following flag is set TRUE, the module will print trace info
of SQL execution in the UNIV_SQL_DEBUG version */
extern ibool	que_trace_on;

/***************************************************************************
Adds a query graph to the session's list of graphs. */

void
que_graph_publish(
/*==============*/
	que_t*	graph,	/* in: graph */
	sess_t*	sess);	/* in: session */
/***************************************************************************
Creates a query graph fork node. */

que_fork_t*
que_fork_create(
/*============*/
					/* out, own: fork node */
	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. */

que_thr_t*
que_thr_create(
/*===========*/
				/* out, own: query thread node */
	que_fork_t*	parent,	/* in: parent node, i.e., a fork node */
	mem_heap_t*	heap);	/* in: memory heap where created */
/**************************************************************************
Checks if the query graph is in a state where it should be freed, and
frees it in that case. If the session is in a state where it should be
closed, also this is done. */

ibool
que_graph_try_free(
/*===============*/
			/* out: TRUE if freed */
	que_t*	graph);	/* in: query graph */
/**************************************************************************
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 kernel mutex has
to be reserved. */

ibool
que_thr_stop(
/*=========*/
				/* out: TRUE if stopped */
	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.c, 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 */
/**************************************************************************
Runs query threads. Note that the individual query thread which is run
within this function may change if, e.g., the OS thread executing this
function uses a threshold amount of resources. */

void
que_run_threads(
/*============*/
	que_thr_t*	thr);	/* in: query thread which is run initially */
/**************************************************************************
After signal handling is finished, returns control to a query graph error
handling routine. (Currently, just returns the control to the root of the
graph so that the graph can communicate an error message to the client.) */

void
que_fork_error_handle(
/*==================*/
	trx_t*	trx,	/* in: trx */
	que_t*	fork);	/* in: query graph which was run before signal
			handling started, NULL not allowed */
/**************************************************************************
Handles an SQL error noticed during query thread execution. At the moment,
does nothing! */

void
que_thr_handle_error(
/*=================*/
	que_thr_t*	thr,	/* in: query thread */
	ulint		err_no,	/* in: error number */
	byte*		err_str,/* in, own: error string or NULL; NOTE: the
				function will take care of freeing of the
				string! */
	ulint		err_len);/* in: error string length */	
/**************************************************************************
Moves a suspended query thread to the QUE_THR_RUNNING state and releases
a single 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. */

void
que_thr_end_wait(
/*=============*/
	que_thr_t*	thr,		/* in: query thread in the
					QUE_THR_LOCK_WAIT,
					or QUE_THR_PROCEDURE_WAIT, or
					QUE_THR_SIG_REPLY_WAIT state */
	que_thr_t**	next_thr);	/* in/out: next query thread to run;
					if the value which is passed in is
					a pointer to a NULL pointer, then the
					calling function can start running
					a new query thread */
/**************************************************************************
Same as que_thr_end_wait, but no parameter next_thr available. */

void
que_thr_end_wait_no_next_thr(
/*=========================*/
	que_thr_t*	thr);		/* in: query thread in the
					QUE_THR_LOCK_WAIT,
					or QUE_THR_PROCEDURE_WAIT, or
					QUE_THR_SIG_REPLY_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. */

que_thr_t*
que_fork_start_command(
/*===================*/
				/* out: 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_fork_t* 	fork,	/* in: a query fork */
	ulint		command,/* in: command SESS_COMM_FETCH_NEXT, ... */
	ulint		param);	/* in: possible parameter to the command */
/***************************************************************************
Gets the trx of a query thread. */
UNIV_INLINE
trx_t*
thr_get_trx(
/*========*/
	que_thr_t*	thr);	/* in: query thread */
/***************************************************************************
Gets the type of a graph node. */
UNIV_INLINE
ulint
que_node_get_type(
/*==============*/
	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. */
UNIV_INLINE
ulint
que_node_get_val_buf_size(
/*======================*/
				/* out: val buffer size, not defined if
				val.data == NULL in node */
	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. */
UNIV_INLINE
que_node_t*
que_node_get_parent(
/*================*/
				/* out: parent node or NULL */
	que_node_t*	node);	/* in: node */
/*************************************************************************
Catenates a query graph node to a list of them, possible empty list. */
UNIV_INLINE
que_node_t*
que_node_list_add_last(
/*===================*/
					/* out: one-way list of nodes */
	que_node_t*	node_list,	/* in: node list, or NULL */
	que_node_t*	node);		/* in: node */
/*************************************************************************
Gets a query graph node list length. */
UNIV_INLINE
ulint
que_node_list_get_len(
/*==================*/
					/* out: length, for NULL list 0 */
	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. */
UNIV_INLINE
ibool
que_thr_peek_stop(
/*==============*/
				/* out: TRUE if should be stopped; NOTE that
				if the peek is made without reserving the
				kernel mutex, then another peek with the
				mutex reserved is necessary before deciding
				the actual stopping */
	que_thr_t*	thr);	/* in: query thread */
/***************************************************************************
Returns TRUE if the query graph is for a SELECT statement. */
UNIV_INLINE
ibool
que_graph_is_select(
/*================*/
					/* out: TRUE if a 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 */


/* Query graph query thread node: the fields are protected by the kernel
mutex with the exceptions named below */

struct que_thr_struct{
	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 */
	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 */
	ulint		state;		/* state of the query thread */
	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 */
	/*------------------------------*/
	/* The following fields are private to the OS thread executing the
	query thread, and are not protected by the kernel 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 */
};

#define QUE_THR_MAGIC_N		8476583
#define QUE_THR_MAGIC_FREED	123461526

/* Query graph fork node: its fields are protected by the kernel mutex */
struct que_fork_struct{
	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' */
	ulint		id;		/* id of this query graph */
	ulint		command;	/* command currently executed in the
					graph */
	ulint		param;		/* possible command parameter */

	/* 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 */
	dulint		n_inserts;	/* number of rows inserted */
	dulint		n_updates;	/* number of rows updated */
	dulint		n_deletes;	/* number of rows deleted */
	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

/* Query thread states */
#define QUE_THR_RUNNING		1
#define QUE_THR_PROCEDURE_WAIT	2
#define	QUE_THR_COMPLETED	3	/* 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 */
#define QUE_THR_COMMAND_WAIT	4
#define QUE_THR_LOCK_WAIT	5
#define QUE_THR_SIG_REPLY_WAIT	6
#define QUE_THR_SUSPENDED	7
#define QUE_THR_ERROR		8

/* From where the cursor position is counted */
#define QUE_CUR_NOT_DEFINED	1
#define QUE_CUR_START		2
#define	QUE_CUR_END		3


#ifndef UNIV_NONINL
#include "que0que.ic"
#endif

#endif