que0que.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

	return(TRUE);
}

/**************************************************************************
Calls que_graph_free_recursive for statements in a statement list. */
static
void
que_graph_free_stat_list(
/*=====================*/
	que_node_t*	node)	/* in: first query graph node in the list */
{
	while (node) {
		que_graph_free_recursive(node);

		node = que_node_get_next(node);
	}
}

/**************************************************************************
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 */
{
	que_fork_t*	fork;
	que_thr_t*	thr;
	undo_node_t*	undo;
	sel_node_t*	sel;
	ins_node_t*	ins;
	upd_node_t*	upd;
	tab_node_t*	cre_tab;
	ind_node_t*	cre_ind;
	
	if (node == NULL) {

		return;
	}

	switch (que_node_get_type(node)) {

	case QUE_NODE_FORK:
		fork = node;

		thr = UT_LIST_GET_FIRST(fork->thrs);

		while (thr) {
			que_graph_free_recursive(thr);

			thr = UT_LIST_GET_NEXT(thrs, thr);
		}

		break;
	case QUE_NODE_THR:

		thr = node;

		if (thr->magic_n != QUE_THR_MAGIC_N) {
			fprintf(stderr,
		"que_thr struct appears corrupt; magic n %lu\n",
				(unsigned long) thr->magic_n);
			mem_analyze_corruption((byte*)thr);
			ut_error;
		}

		thr->magic_n = QUE_THR_MAGIC_FREED;

		que_graph_free_recursive(thr->child);

		break;
	case QUE_NODE_UNDO:

		undo = node;

		mem_heap_free(undo->heap);

		break;
	case QUE_NODE_SELECT:

		sel = node;

		sel_node_free_private(sel);

		break;
	case QUE_NODE_INSERT:

		ins = node;

		que_graph_free_recursive(ins->select);

		mem_heap_free(ins->entry_sys_heap);

		break;
	case QUE_NODE_UPDATE:

		upd = node;

		if (upd->in_mysql_interface) {
		
			btr_pcur_free_for_mysql(upd->pcur);
		}

		que_graph_free_recursive(upd->cascade_node);		

		if (upd->cascade_heap) {
			mem_heap_free(upd->cascade_heap);
		}
		
		que_graph_free_recursive(upd->select);

		mem_heap_free(upd->heap);

		break;
	case QUE_NODE_CREATE_TABLE:
		cre_tab = node;
	
		que_graph_free_recursive(cre_tab->tab_def);
		que_graph_free_recursive(cre_tab->col_def);
		que_graph_free_recursive(cre_tab->commit_node);

		mem_heap_free(cre_tab->heap);

		break;
	case QUE_NODE_CREATE_INDEX:
		cre_ind = node;
	
		que_graph_free_recursive(cre_ind->ind_def);
		que_graph_free_recursive(cre_ind->field_def);
		que_graph_free_recursive(cre_ind->commit_node);

		mem_heap_free(cre_ind->heap);

		break;
	case QUE_NODE_PROC:
		que_graph_free_stat_list(((proc_node_t*)node)->stat_list);

		break;
	case QUE_NODE_IF:
		que_graph_free_stat_list(((if_node_t*)node)->stat_list);
		que_graph_free_stat_list(((if_node_t*)node)->else_part);
		que_graph_free_stat_list(((if_node_t*)node)->elsif_list);

		break;
	case QUE_NODE_ELSIF:
		que_graph_free_stat_list(((elsif_node_t*)node)->stat_list);

		break;
	case QUE_NODE_WHILE:
		que_graph_free_stat_list(((while_node_t*)node)->stat_list);

		break;
	case QUE_NODE_FOR:
		que_graph_free_stat_list(((for_node_t*)node)->stat_list);

		break;

	case QUE_NODE_ASSIGNMENT:
	case QUE_NODE_RETURN:
	case QUE_NODE_COMMIT:
	case QUE_NODE_ROLLBACK:
	case QUE_NODE_LOCK:
	case QUE_NODE_FUNC:
	case QUE_NODE_ORDER:
	case QUE_NODE_ROW_PRINTF:
	case QUE_NODE_OPEN:
	case QUE_NODE_FETCH:
		/* No need to do anything */

		break;
	default:
		fprintf(stderr,
		"que_node struct appears corrupt; type %lu\n",
			(unsigned long) que_node_get_type(node));
		mem_analyze_corruption((byte*)node);
		ut_error;
	}
}

/**************************************************************************
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! */
{
	ut_ad(graph);

	if (graph->sym_tab) {
		/* The following call frees dynamic memory allocated
		for variables etc. during execution. Frees also explicit
		cursor definitions. */
		
		sym_tab_free_private(graph->sym_tab);
	}

	que_graph_free_recursive(graph);

	mem_heap_free(graph->heap);
}

/**************************************************************************
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 */
{
	sess_t*	sess;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */

	sess = (graph->trx)->sess;
	
	if ((graph->state == QUE_FORK_BEING_FREED)
					&& (graph->n_active_thrs == 0)) {

		UT_LIST_REMOVE(graphs, sess->graphs, graph);
		que_graph_free(graph);

		sess_try_close(sess);

		return(TRUE);
	}

	return(FALSE);
}

/**************************************************************************
Handles an SQL error noticed during query thread execution. Currently,
does nothing! */

void
que_thr_handle_error(
/*=================*/
	que_thr_t*	thr __attribute__((unused)),
				/* in: query thread */
	ulint		err_no __attribute__((unused)),
				/* in: error number */
	byte*		err_str __attribute__((unused)),
				/* in, own: error string or NULL; NOTE: the
				function will take care of freeing of the
				string! */
	ulint		err_len __attribute__((unused)))
				/* in: error string length */	
{
	/* Does nothing */
}

/********************************************************************
Performs an execution step on a thr node. */
static
que_thr_t*
que_thr_node_step(
/*==============*/
				/* out: query thread to run next, or NULL
				if none */
	que_thr_t*	thr)	/* in: query thread where run_node must
				be the thread node itself */
{
	ut_ad(thr->run_node == thr);
	
	if (thr->prev_node == thr->common.parent) {
		/* If control to the node came from above, it is just passed
		on */

		thr->run_node = thr->child;
	
		return(thr);
	}

	mutex_enter(&kernel_mutex);

	if (que_thr_peek_stop(thr)) {
	
		mutex_exit(&kernel_mutex);

		return(thr);
	}

	/* Thread execution completed */
	
	thr->state = QUE_THR_COMPLETED;
	
	mutex_exit(&kernel_mutex);

	return(NULL);
}

/**************************************************************************
Moves a thread from another state to the QUE_THR_RUNNING state. Increments
the n_active_thrs counters of the query graph and transaction if thr was
not active.
***NOTE***: This and ..._mysql are  the only functions in which such a
transition is allowed to happen! */
static
void
que_thr_move_to_run_state(
/*======================*/
	que_thr_t*	thr)	/* in: an query thread */
{
	trx_t*	trx;

	ut_ad(thr->state != QUE_THR_RUNNING);

	trx = thr_get_trx(thr);

	if (!thr->is_active) {

		(thr->graph)->n_active_thrs++;

		trx->n_active_thrs++;

		thr->is_active = TRUE;

		ut_ad((thr->graph)->n_active_thrs == 1);
		ut_ad(trx->n_active_thrs == 1);
	}
	
	thr->state = QUE_THR_RUNNING;
}

/**************************************************************************
Decrements the query thread reference counts in the query graph and the
transaction. May start signal handling, e.g., a rollback.
*** NOTE ***:
This and que_thr_stop_for_mysql are
the only functions where the reference count can be decremented and
this function may only be called from inside que_run_threads or
que_thr_check_if_switch! These restrictions exist to make the rollback code
easier to maintain. */
static
void
que_thr_dec_refer_count(
/*====================*/
	que_thr_t*	thr,		/* in: query thread */
	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 */ 
{
	que_fork_t*	fork;
	trx_t*		trx;
	sess_t*		sess;
	ulint		fork_type;
	ibool		stopped;
	
	fork = thr->common.parent;
	trx = thr->graph->trx;
	sess = trx->sess;

	mutex_enter(&kernel_mutex);

	ut_a(thr->is_active);

	if (thr->state == QUE_THR_RUNNING) {

		stopped = que_thr_stop(thr);

		if (!stopped) {
			/* The reason for the thr suspension or wait was
			already canceled before we came here: continue
			running the thread */

			/* fputs("!!!!!!!! Wait already ended: continue thr\n",
				stderr); */

			if (next_thr && *next_thr == NULL) {
				*next_thr = thr;
			} else {
				ut_a(0);
				srv_que_task_enqueue_low(thr);
			}

			mutex_exit(&kernel_mutex);

			return;
		}
	}	

	ut_ad(fork->n_active_thrs == 1);
	ut_ad(trx->n_active_thrs == 1);

	fork->n_active_thrs--;
	trx->n_active_thrs--;

	thr->is_active = FALSE;

	if (trx->n_active_thrs > 0) {

		mutex_exit(&kernel_mutex);

		return;
	}
	
	fork_type = fork->fork_type;

	/* Check if all query threads in the same fork are completed */

	if (que_fork_all_thrs_in_state(fork, QUE_THR_COMPLETED)) {

		if (fork_type == QUE_FORK_ROLLBACK) {
			/* This is really the undo graph used in rollback,
			no roll_node in this graph */
			
			ut_ad(UT_LIST_GET_LEN(trx->signals) > 0);
			ut_ad(trx->handling_signals == TRUE);
			
			trx_finish_rollback_off_kernel(fork, trx, next_thr);
			
		} else if (fork_type == QUE_FORK_PURGE) {

			/* Do nothing */