trx0trx.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

	trx_commit_off_kernel(trx);

	ut_ad(UT_LIST_GET_LEN(trx->wait_thrs) == 0);

	/* Remove all TRX_SIG_COMMIT signals from the signal queue and send
	reply messages to them */

	sig = UT_LIST_GET_FIRST(trx->signals);

	while (sig != NULL) {
		next_sig = UT_LIST_GET_NEXT(signals, sig);

		if (sig->type == TRX_SIG_COMMIT) {

			trx_sig_reply(sig, next_thr);
			trx_sig_remove(trx, sig);
		}

		sig = next_sig;
	}

	trx->que_state = TRX_QUE_RUNNING;
}

/***************************************************************
The transaction must be in the TRX_QUE_LOCK_WAIT state. Puts it to
the TRX_QUE_RUNNING state and releases query threads which were
waiting for a lock in the wait_thrs list. */

void
trx_end_lock_wait(
/*==============*/
	trx_t*	trx)	/* in: transaction */
{
	que_thr_t*	thr;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(trx->que_state == TRX_QUE_LOCK_WAIT);
	
	thr = UT_LIST_GET_FIRST(trx->wait_thrs);

	while (thr != NULL) {
		que_thr_end_wait_no_next_thr(thr);

		UT_LIST_REMOVE(trx_thrs, trx->wait_thrs, thr);
			
		thr = UT_LIST_GET_FIRST(trx->wait_thrs);
	}

	trx->que_state = TRX_QUE_RUNNING;
}

/***************************************************************
Moves the query threads in the lock wait list to the SUSPENDED state and puts
the transaction to the TRX_QUE_RUNNING state. */
static
void
trx_lock_wait_to_suspended(
/*=======================*/
	trx_t*	trx)	/* in: transaction in the TRX_QUE_LOCK_WAIT state */
{
	que_thr_t*	thr;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(trx->que_state == TRX_QUE_LOCK_WAIT);
	
	thr = UT_LIST_GET_FIRST(trx->wait_thrs);

	while (thr != NULL) {
		thr->state = QUE_THR_SUSPENDED;
	
		UT_LIST_REMOVE(trx_thrs, trx->wait_thrs, thr);
			
		thr = UT_LIST_GET_FIRST(trx->wait_thrs);
	}

	trx->que_state = TRX_QUE_RUNNING;
}

/***************************************************************
Moves the query threads in the sig reply wait list of trx to the SUSPENDED
state. */
static
void
trx_sig_reply_wait_to_suspended(
/*============================*/
	trx_t*	trx)	/* in: transaction */
{
	trx_sig_t*	sig;
	que_thr_t*	thr;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	
	sig = UT_LIST_GET_FIRST(trx->reply_signals);

	while (sig != NULL) {
		thr = sig->receiver;

		ut_ad(thr->state == QUE_THR_SIG_REPLY_WAIT);
		
		thr->state = QUE_THR_SUSPENDED;

		sig->receiver = NULL;
	
		UT_LIST_REMOVE(reply_signals, trx->reply_signals, sig);
			
		sig = UT_LIST_GET_FIRST(trx->reply_signals);
	}
}

/*********************************************************************
Checks the compatibility of a new signal with the other signals in the
queue. */
static
ibool
trx_sig_is_compatible(
/*==================*/
			/* out: TRUE if the signal can be queued */
	trx_t*	trx,	/* in: trx handle */
	ulint	type,	/* in: signal type */
	ulint	sender)	/* in: TRX_SIG_SELF or TRX_SIG_OTHER_SESS */
{
	trx_sig_t*	sig;

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

	if (UT_LIST_GET_LEN(trx->signals) == 0) {

		return(TRUE);
	}
	
	if (sender == TRX_SIG_SELF) {
		if (type == TRX_SIG_ERROR_OCCURRED) {

			return(TRUE);

		} else if (type == TRX_SIG_BREAK_EXECUTION) {

			return(TRUE);
		} else {
			return(FALSE);
		}
	}

	ut_ad(sender == TRX_SIG_OTHER_SESS);

	sig = UT_LIST_GET_FIRST(trx->signals);

	if (type == TRX_SIG_COMMIT) {
		while (sig != NULL) {

			if (sig->type == TRX_SIG_TOTAL_ROLLBACK) {

				return(FALSE);
			}

			sig = UT_LIST_GET_NEXT(signals, sig);
		}

 		return(TRUE);

	} else if (type == TRX_SIG_TOTAL_ROLLBACK) {
		while (sig != NULL) {

			if (sig->type == TRX_SIG_COMMIT) {

				return(FALSE);
			}

			sig = UT_LIST_GET_NEXT(signals, sig);
		}

		return(TRUE);

	} else if (type == TRX_SIG_BREAK_EXECUTION) {

		return(TRUE);		
	} else {
		ut_error;

		return(FALSE);
	}
}

/********************************************************************
Sends a signal to a trx object. */

ibool
trx_sig_send(
/*=========*/
					/* out: TRUE if the signal was
					successfully delivered */
	trx_t*		trx,		/* in: trx handle */
	ulint		type,		/* in: signal type */
	ulint		sender,		/* in: TRX_SIG_SELF or
					TRX_SIG_OTHER_SESS */
	que_thr_t*	receiver_thr,	/* in: query thread which wants the
					reply, or NULL; if type is
					TRX_SIG_END_WAIT, this must be NULL */
	trx_savept_t* 	savept,		/* in: possible rollback savepoint, or
					NULL */
	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; if the parameter
					is NULL, it is ignored */
{
	trx_sig_t*	sig;
	trx_t*		receiver_trx;

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

	if (!trx_sig_is_compatible(trx, type, sender)) {
		/* The signal is not compatible with the other signals in
		the queue: do nothing */

		ut_error;
		
		return(FALSE);
	}

	/* Queue the signal object */

	if (UT_LIST_GET_LEN(trx->signals) == 0) {

		/* The signal list is empty: the 'sig' slot must be unused
		(we improve performance a bit by avoiding mem_alloc) */
		sig = &(trx->sig);		
 	} else {
		/* It might be that the 'sig' slot is unused also in this
		case, but we choose the easy way of using mem_alloc */
		 
		sig = mem_alloc(sizeof(trx_sig_t));
	}

	UT_LIST_ADD_LAST(signals, trx->signals, sig);

	sig->type = type;
	sig->state = TRX_SIG_WAITING;
	sig->sender = sender;
	sig->receiver = receiver_thr;

	if (savept) {
		sig->savept = *savept;
	}

	if (receiver_thr) {
		receiver_trx = thr_get_trx(receiver_thr);

		UT_LIST_ADD_LAST(reply_signals, receiver_trx->reply_signals,
									sig);
	}

	if (trx->sess->state == SESS_ERROR) {
	
		trx_sig_reply_wait_to_suspended(trx);
	}

	if ((sender != TRX_SIG_SELF) || (type == TRX_SIG_BREAK_EXECUTION)) {

		/* The following call will add a TRX_SIG_ERROR_OCCURRED
		signal to the end of the queue, if the session is not yet
		in the error state: */

		ut_error;
	}

	/* If there were no other signals ahead in the queue, try to start
	handling of the signal */

	if (UT_LIST_GET_FIRST(trx->signals) == sig) {
	
		trx_sig_start_handle(trx, next_thr);
	}

	return(TRUE);
}

/********************************************************************
Ends signal handling. If the session is in the error state, and
trx->graph_before_signal_handling != NULL, then returns control to the error
handling routine of the graph (currently just returns the control to the
graph root which then will send an error message to the client). */

void
trx_end_signal_handling(
/*====================*/
	trx_t*	trx)	/* in: trx */
{
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
	ut_ad(trx->handling_signals == TRUE);

	trx->handling_signals = FALSE;

	trx->graph = trx->graph_before_signal_handling;

	if (trx->graph && (trx->sess->state == SESS_ERROR)) {
			
		que_fork_error_handle(trx, trx->graph);
	}
}

/********************************************************************
Starts handling of a trx signal. */

void
trx_sig_start_handle(
/*=================*/
	trx_t*		trx,		/* in: trx handle */
	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; if the parameter
					is NULL, it is ignored */
{
	trx_sig_t*	sig;
	ulint		type;
loop:
	/* We loop in this function body as long as there are queued signals
	we can process immediately */

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

	if (trx->handling_signals && (UT_LIST_GET_LEN(trx->signals) == 0)) {

		trx_end_signal_handling(trx);
	
		return;
	}

	if (trx->conc_state == TRX_NOT_STARTED) {

		trx_start_low(trx, ULINT_UNDEFINED);
	}

	/* If the trx is in a lock wait state, moves the waiting query threads
	to the suspended state */

	if (trx->que_state == TRX_QUE_LOCK_WAIT) {
	
		trx_lock_wait_to_suspended(trx);
	}

	/* If the session is in the error state and this trx has threads
	waiting for reply from signals, moves these threads to the suspended
	state, canceling wait reservations; note that if the transaction has
	sent a commit or rollback signal to itself, and its session is not in
	the error state, then nothing is done here. */

	if (trx->sess->state == SESS_ERROR) {
		trx_sig_reply_wait_to_suspended(trx);
	}
	
	/* If there are no running query threads, we can start processing of a
	signal, otherwise we have to wait until all query threads of this
	transaction are aware of the arrival of the signal. */

	if (trx->n_active_thrs > 0) {

		return;
	}

	if (trx->handling_signals == FALSE) {
		trx->graph_before_signal_handling = trx->graph;

		trx->handling_signals = TRUE;
	}

	sig = UT_LIST_GET_FIRST(trx->signals);
	type = sig->type;

	if (type == TRX_SIG_COMMIT) {

		trx_handle_commit_sig_off_kernel(trx, next_thr);

	} else if ((type == TRX_SIG_TOTAL_ROLLBACK)
				|| (type == TRX_SIG_ROLLBACK_TO_SAVEPT)) { 

		trx_rollback(trx, sig, next_thr);

		/* No further signals can be handled until the rollback
		completes, therefore we return */

		return;

	} else if (type == TRX_SIG_ERROR_OCCURRED) {

		trx_rollback(trx, sig, next_thr);

		/* No further signals can be handled until the rollback
		completes, therefore we return */

		return;

	} else if (type == TRX_SIG_BREAK_EXECUTION) {

		trx_sig_reply(sig, next_thr);
		trx_sig_remove(trx, sig);
	} else {
		ut_error;
	}

	goto loop;
}			

/********************************************************************
Send the reply message when a signal in the queue of the trx has been
handled. */

void
trx_sig_reply(
/*==========*/
	trx_sig_t*	sig,		/* in: signal */
	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 */
{
	trx_t*	receiver_trx;

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

	if (sig->receiver != NULL) {
		ut_ad((sig->receiver)->state == QUE_THR_SIG_REPLY_WAIT);

		receiver_trx = thr_get_trx(sig->receiver);

		UT_LIST_REMOVE(reply_signals, receiver_trx->reply_signals,
									sig);
		ut_ad(receiver_trx->sess->state != SESS_ERROR);
									
		que_thr_end_wait(sig->receiver, next_thr);

		sig->receiver = NULL;

	}
}

/********************************************************************
Removes a signal object from the trx signal queue. */

void
trx_sig_remove(
/*===========*/
	trx_t*		trx,	/* in: trx handle */
	trx_sig_t*	sig)	/* in, own: signal */
{
	ut_ad(trx && sig);
#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */

	ut_ad(sig->receiver == NULL);

	UT_LIST_REMOVE(signals, trx->signals, sig);
	sig->type = 0;	/* reset the field to catch possible bugs */

	if (sig != &(trx->sig)) {
		mem_free(sig);
	}
}

/*************************************************************************
Creates a commit command node struct. */

commit_node_t*
commit_node_create(
/*===============*/
				/* out, own: commit node struct */
	mem_heap_t*	heap)	/* in: mem heap where created */
{
	commit_node_t*	node;

	node = mem_heap_alloc(heap, sizeof(commit_node_t));
	node->common.type  = QUE_NODE_COMMIT;
	node->state = COMMIT_NODE_SEND;
	
	return(node);
}

/***************************************************************
Performs an execution step for a commit type node in a query graph. */

que_thr_t*
trx_commit_step(
/*============*/
				/* out: query thread to run next, or NULL */
	que_thr_t*	thr)	/* in: query thread */
{
	commit_node_t*	node;
	que_thr_t*	next_thr;
	ibool		success;