Cset exclude: marko@hundin.mysql.fi|ChangeSet|20040525171209|56870

BitKeeper/deleted/.del-srv0que.c~d1feebb77b5a9b96:
  Exclude
BitKeeper/deleted/.del-srv0que.h~f12ecb4b5afe203e:
  Exclude
innobase/include/que0que.h:
  Exclude
innobase/include/trx0roll.h:
  Exclude
innobase/include/trx0trx.h:
  Exclude
innobase/include/usr0sess.h:
  Exclude
innobase/que/que0que.c:
  Exclude
innobase/srv/Makefile.am:
  Exclude
innobase/include/Makefile.am:
  Exclude
innobase/srv/srv0srv.c:
  Exclude
innobase/trx/trx0purge.c:
  Exclude
innobase/trx/trx0roll.c:
  Exclude
innobase/trx/trx0trx.c:
  Exclude
innobase/usr/usr0sess.c:
  Exclude

12 files changed, 338 insertions, 101 deletions

diff --git a/innobase/include/Makefile.am b/innobase/include/Makefile.am
index 5ec70da97a2..102d25566da 100644
--- a/innobase/include/Makefile.am
+++ b/innobase/include/Makefile.am
@@ -43,7 +43,7 @@ noinst_HEADERS = btr0btr.h btr0btr.ic btr0cur.h btr0cur.ic \
         row0purge.ic row0row.h row0row.ic row0sel.h row0sel.ic \
         row0types.h row0uins.h row0uins.ic row0umod.h row0umod.ic \
         row0undo.h row0undo.ic row0upd.h row0upd.ic row0vers.h \
-        row0vers.ic srv0srv.h srv0srv.ic srv0start.h \
+        row0vers.ic srv0que.h srv0srv.h srv0srv.ic srv0start.h \
         sync0arr.h sync0arr.ic sync0rw.h \
         sync0rw.ic sync0sync.h sync0sync.ic sync0types.h \
         thr0loc.h thr0loc.ic trx0purge.h trx0purge.ic trx0rec.h \
diff --git a/innobase/include/que0que.h b/innobase/include/que0que.h
index a438116781f..bcd7aed7e88 100644
--- a/innobase/include/que0que.h
+++ b/innobase/include/que0que.h
@@ -152,6 +152,17 @@ 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! */
 
@@ -170,15 +181,18 @@ 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. */
 
-que_thr_t*
+void
 que_thr_end_wait(
 /*=============*/
-					/* out: next query thread to run;
-					NULL if none */
-	que_thr_t*	thr);		/* in: query thread in the
+	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. */
 
diff --git a/innobase/include/trx0roll.h b/innobase/include/trx0roll.h
index e9c74dc6651..0d7126c9c57 100644
--- a/innobase/include/trx0roll.h
+++ b/innobase/include/trx0roll.h
@@ -91,12 +91,16 @@ trx_undo_rec_release(
 /*************************************************************************
 Starts a rollback operation. */	
 
-que_thr_t*
+void
 trx_rollback(
 /*=========*/
-				/* out: next query thread to run */
 	trx_t*		trx,	/* in: transaction */
-	trx_sig_t*	sig);	/* in: signal starting the rollback */
+	trx_sig_t*	sig,	/* in: signal starting the rollback */
+	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 */
 /***********************************************************************
 Rollback or clean up transactions which have no user session. If the
 transaction already was committed, then we clean up a possible insert
@@ -108,12 +112,17 @@ trx_rollback_or_clean_all_without_sess(void);
 /********************************************************************
 Finishes a transaction rollback. */
 
-que_thr_t*
+void
 trx_finish_rollback_off_kernel(
 /*===========================*/
-				/* out: next query thread to run */
 	que_t*		graph,	/* in: undo graph which can now be freed */
-	trx_t*		trx);	/* in: transaction */
+	trx_t*		trx,	/* in: transaction */
+	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 this parameter is
+				NULL, it is ignored */
 /********************************************************************
 Builds an undo 'query' graph for a transaction. The actual rollback is
 performed by executing this query graph like a query subprocedure call.
diff --git a/innobase/include/trx0trx.h b/innobase/include/trx0trx.h
index 068333778f3..07d5e5a8215 100644
--- a/innobase/include/trx0trx.h
+++ b/innobase/include/trx0trx.h
@@ -194,10 +194,9 @@ trx_end_lock_wait(
 /********************************************************************
 Sends a signal to a trx object. */
 
-que_thr_t*
+ibool
 trx_sig_send(
 /*=========*/
-					/* out: next query thread to run */
 					/* out: TRUE if the signal was
 					successfully delivered */
 	trx_t*		trx,		/* in: trx handle */
@@ -207,17 +206,27 @@ trx_sig_send(
 	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
+	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 */
 /********************************************************************
 Send the reply message when a signal in the queue of the trx has
 been handled. */
 
-que_thr_t*
+void
 trx_sig_reply(
 /*==========*/
-					/* out: next query thread to run */
-	trx_sig_t*	sig);		/* in: signal */
+	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 */
 /********************************************************************
 Removes the signal object from a trx signal queue. */
 
@@ -229,11 +238,15 @@ trx_sig_remove(
 /********************************************************************
 Starts handling of a trx signal. */
 
-que_thr_t*
+void
 trx_sig_start_handle(
 /*=================*/
-				/* out: next query thread to run, or NULL */
-	trx_t*		trx);	/* in: trx 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 */
 /********************************************************************
 Ends signal handling. If the session is in the error state, and
 trx->graph_before_signal_handling != NULL, returns control to the error
diff --git a/innobase/include/usr0sess.h b/innobase/include/usr0sess.h
index aeff7191e68..c7bcfb20fed 100644
--- a/innobase/include/usr0sess.h
+++ b/innobase/include/usr0sess.h
@@ -38,6 +38,7 @@ sess_try_close(
 
 /* The session handle. All fields are protected by the kernel mutex */
 struct sess_struct{
+	ulint		state;		/* state of the session */
 	trx_t*		trx;		/* transaction object permanently
 					assigned for the session: the
 					transaction instance designated by the
@@ -48,6 +49,11 @@ struct sess_struct{
 					session */
 };
 
+/* Session states */
+#define SESS_ACTIVE		1
+#define SESS_ERROR		2	/* session contains an error message
+					which has not yet been communicated
+					to the client */
 #ifndef UNIV_NONINL
 #include "usr0sess.ic"
 #endif
diff --git a/innobase/que/que0que.c b/innobase/que/que0que.c
index 0a2e607807a..b90a5eb3a61 100644
--- a/innobase/que/que0que.c
+++ b/innobase/que/que0que.c
@@ -12,6 +12,7 @@ Created 5/27/1996 Heikki Tuuri
 #include "que0que.ic"
 #endif
 
+#include "srv0que.h"
 #include "usr0sess.h"
 #include "trx0trx.h"
 #include "trx0roll.h"
@@ -174,15 +175,19 @@ 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. */
 
-que_thr_t*
+void
 que_thr_end_wait(
 /*=============*/
-					/* out: next query thread to run;
-					NULL if none */
-	que_thr_t*	thr)		/* in: query thread in the
+	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; if NULL is passed
+					as the parameter, it is ignored */
 {
 	ibool	was_active;
 
@@ -201,8 +206,17 @@ que_thr_end_wait(
 	
 	que_thr_move_to_run_state(thr);
 
-	return(was_active ? NULL : thr);
-}
+	if (was_active) {
+
+		return;
+	}	
+
+	if (next_thr && *next_thr == NULL) {
+		*next_thr = thr;
+	} else {
+		srv_que_task_enqueue_low(thr);
+	}
+}	
 
 /**************************************************************************
 Same as que_thr_end_wait, but no parameter next_thr available. */
@@ -239,6 +253,8 @@ que_thr_end_wait_no_next_thr(
 	for the lock to be released: */
 	
 	srv_release_mysql_thread_if_suspended(thr);
+
+	/* srv_que_task_enqueue_low(thr); */
 }
 
 /**************************************************************************
@@ -339,6 +355,48 @@ que_fork_start_command(
 	return(NULL);
 }
 
+/**************************************************************************
+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 __attribute__((unused)),	/* in: trx */
+	que_t*	fork)	/* in: query graph which was run before signal
+			handling started, NULL not allowed */
+{
+	que_thr_t*	thr;
+
+#ifdef UNIV_SYNC_DEBUG
+	ut_ad(mutex_own(&kernel_mutex));
+#endif /* UNIV_SYNC_DEBUG */
+	ut_ad(trx->sess->state == SESS_ERROR);
+	ut_ad(UT_LIST_GET_LEN(trx->reply_signals) == 0);
+	ut_ad(UT_LIST_GET_LEN(trx->wait_thrs) == 0);
+
+	thr = UT_LIST_GET_FIRST(fork->thrs);
+
+	while (thr != NULL) {
+		ut_ad(!thr->is_active);
+		ut_ad(thr->state != QUE_THR_SIG_REPLY_WAIT);
+		ut_ad(thr->state != QUE_THR_LOCK_WAIT);
+		
+		thr->run_node = thr;
+		thr->prev_node = thr->child;
+		thr->state = QUE_THR_COMPLETED;
+		
+		thr = UT_LIST_GET_NEXT(thrs, thr);
+	}
+
+	thr = UT_LIST_GET_FIRST(fork->thrs);
+	
+	que_thr_move_to_run_state(thr);
+
+	srv_que_task_enqueue_low(thr);
+}
+
 /********************************************************************
 Tests if all the query threads in the same fork have a given state. */
 UNIV_INLINE
@@ -707,18 +765,22 @@ 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
-que_thr_t*
+void
 que_thr_dec_refer_count(
 /*====================*/
-					/* out: next query thread to run */
-	que_thr_t*	thr)		/* in: query thread */
+	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;
-	que_thr_t*	next_thr = NULL;
-
+	ibool		stopped;
+	
 	fork = thr->common.parent;
 	trx = thr->graph->trx;
 	sess = trx->sess;
@@ -729,7 +791,9 @@ que_thr_dec_refer_count(
 
 	if (thr->state == QUE_THR_RUNNING) {
 
-		if (!que_thr_stop(thr)) {
+		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 */
@@ -737,9 +801,15 @@ que_thr_dec_refer_count(
 			/* fputs("!!!!!!!! Wait already ended: continue thr\n",
 				stderr); */
 
+			if (next_thr && *next_thr == NULL) {
+				*next_thr = thr;
+			} else {
+				srv_que_task_enqueue_low(thr);
+			}
+
 			mutex_exit(&kernel_mutex);
 
-			return(thr);
+			return;
 		}
 	}	
 
@@ -755,7 +825,7 @@ que_thr_dec_refer_count(
 
 		mutex_exit(&kernel_mutex);
 
-		return(next_thr);
+		return;
 	}
 	
 	fork_type = fork->fork_type;
@@ -771,7 +841,7 @@ que_thr_dec_refer_count(
 			ut_ad(UT_LIST_GET_LEN(trx->signals) > 0);
 			ut_ad(trx->handling_signals == TRUE);
 			
-			next_thr = trx_finish_rollback_off_kernel(fork, trx);
+			trx_finish_rollback_off_kernel(fork, trx, next_thr);
 			
 		} else if (fork_type == QUE_FORK_PURGE) {
 
@@ -793,7 +863,7 @@ que_thr_dec_refer_count(
 		zero, then we start processing a signal; from it we may get
 		a new query thread to run */
 
-		next_thr = trx_sig_start_handle(trx);
+		trx_sig_start_handle(trx, next_thr);
 	}
 
 	if (trx->handling_signals && UT_LIST_GET_LEN(trx->signals) == 0) {
@@ -802,8 +872,6 @@ que_thr_dec_refer_count(
 	}
 
 	mutex_exit(&kernel_mutex);
-
-	return(next_thr);
 }
 
 /**************************************************************************
@@ -1175,7 +1243,6 @@ loop:
 	/*-------------------------*/
 	next_thr = que_thr_step(thr);
 	/*-------------------------*/
-	ut_a(next_thr == thr || next_thr == NULL);
 
 	/* Test the effect on performance of adding extra mutex
 	reservations */
@@ -1192,7 +1259,7 @@ loop:
 	loop_count++;
 
 	if (next_thr != thr) {
-		next_thr = que_thr_dec_refer_count(thr);
+		que_thr_dec_refer_count(thr, &next_thr);
 
 		if (next_thr == NULL) {
 
diff --git a/innobase/srv/Makefile.am b/innobase/srv/Makefile.am
index 37fd73a4bf0..752683b82b8 100644
--- a/innobase/srv/Makefile.am
+++ b/innobase/srv/Makefile.am
@@ -19,6 +19,6 @@ include ../include/Makefile.i
 
 noinst_LIBRARIES =	libsrv.a
 
-libsrv_a_SOURCES =	srv0srv.c srv0start.c
+libsrv_a_SOURCES =	srv0srv.c srv0que.c srv0start.c
 
 EXTRA_PROGRAMS =	
diff --git a/innobase/srv/srv0srv.c b/innobase/srv/srv0srv.c
index afc6b996b89..a78bd0d864c 100644
--- a/innobase/srv/srv0srv.c
+++ b/innobase/srv/srv0srv.c
@@ -34,6 +34,7 @@ Created 10/8/1995 Heikki Tuuri
 #include "sync0sync.h"
 #include "thr0loc.h"
 #include "que0que.h"
+#include "srv0que.h"
 #include "log0recv.h"
 #include "pars0pars.h"
 #include "usr0sess.h"
diff --git a/innobase/trx/trx0purge.c b/innobase/trx/trx0purge.c
index 9eae5c37335..a8b6b9fcc21 100644
--- a/innobase/trx/trx0purge.c
+++ b/innobase/trx/trx0purge.c
@@ -23,6 +23,7 @@ Created 3/26/1996 Heikki Tuuri
 #include "row0purge.h"
 #include "row0upd.h"
 #include "trx0rec.h"
+#include "srv0que.h"
 #include "os0thread.h"
 
 /* The global data structure coordinating a purge */
@@ -1059,6 +1060,8 @@ trx_purge(void)
 
 	mutex_exit(&kernel_mutex);
 
+/*	srv_que_task_enqueue(thr2); */
+
 	if (srv_print_thread_releases) {
 	
 		fputs("Starting purge\n", stderr);
diff --git a/innobase/trx/trx0roll.c b/innobase/trx/trx0roll.c
index eccc9cab7f1..eed5e79a20f 100644
--- a/innobase/trx/trx0roll.c
+++ b/innobase/trx/trx0roll.c
@@ -20,6 +20,7 @@ Created 3/26/1996 Heikki Tuuri
 #include "trx0rec.h"
 #include "que0que.h"
 #include "usr0sess.h"
+#include "srv0que.h"
 #include "srv0start.h"
 #include "row0undo.h"
 #include "row0mysql.h"
@@ -931,15 +932,21 @@ trx_undo_rec_release(
 /*************************************************************************
 Starts a rollback operation. */	
 
-que_thr_t*
+void
 trx_rollback(
 /*=========*/
-				/* out: next query thread to run */
 	trx_t*		trx,	/* in: transaction */
-	trx_sig_t*	sig)	/* in: signal starting the rollback */
+	trx_sig_t*	sig,	/* in: signal starting the rollback */
+	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 passed value is
+				NULL, the parameter is ignored */
 {
 	que_t*		roll_graph;
 	que_thr_t*	thr;
+/*	que_thr_t*	thr2; */
 
 #ifdef UNIV_SYNC_DEBUG
 	ut_ad(mutex_own(&kernel_mutex));
@@ -981,7 +988,18 @@ trx_rollback(
 	thr = que_fork_start_command(roll_graph);
 
 	ut_ad(thr);
-	return(thr);
+
+/*	thr2 = que_fork_start_command(roll_graph);
+
+	ut_ad(thr2); */
+	
+	if (next_thr && (*next_thr == NULL)) {
+		*next_thr = thr;
+/*		srv_que_task_enqueue_low(thr2); */
+	} else {
+		srv_que_task_enqueue_low(thr);
+/*		srv_que_task_enqueue_low(thr2); */
+	}
 }
 
 /********************************************************************
@@ -1053,14 +1071,17 @@ trx_finish_error_processing(
 /*************************************************************************
 Finishes a partial rollback operation. */
 static
-que_thr_t*
+void
 trx_finish_partial_rollback_off_kernel(
 /*===================================*/
-				/* out: next query thread to run */
-	trx_t*		trx)	/* in: transaction */
+	trx_t*		trx,	/* in: transaction */
+	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 this
+				parameter is NULL, it is ignored */
 {
 	trx_sig_t*	sig;
-	que_thr_t*	next_thr;
 
 #ifdef UNIV_SYNC_DEBUG
 	ut_ad(mutex_own(&kernel_mutex));
@@ -1071,26 +1092,29 @@ trx_finish_partial_rollback_off_kernel(
 	/* Remove the signal from the signal queue and send reply message
 	to it */
 
-	next_thr = trx_sig_reply(sig);
+	trx_sig_reply(sig, next_thr);
 	trx_sig_remove(trx, sig);
 
 	trx->que_state = TRX_QUE_RUNNING;
-	return(next_thr);
 }
 
 /********************************************************************
 Finishes a transaction rollback. */
 
-que_thr_t*
+void
 trx_finish_rollback_off_kernel(
 /*===========================*/
-				/* out: next query thread to run */
 	que_t*		graph,	/* in: undo graph which can now be freed */
-	trx_t*		trx)	/* in: transaction */
+	trx_t*		trx,	/* in: transaction */
+	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 this parameter is
+				NULL, it is ignored */
 {
 	trx_sig_t*	sig;
 	trx_sig_t*	next_sig;
-	que_thr_t*	next_thr;
 	
 #ifdef UNIV_SYNC_DEBUG
 	ut_ad(mutex_own(&kernel_mutex));
@@ -1105,13 +1129,15 @@ trx_finish_rollback_off_kernel(
 
 	if (sig->type == TRX_SIG_ROLLBACK_TO_SAVEPT) {
 
-		return(trx_finish_partial_rollback_off_kernel(trx));
+		trx_finish_partial_rollback_off_kernel(trx, next_thr);
+
+		return;
 
 	} else if (sig->type == TRX_SIG_ERROR_OCCURRED) {
 
 		trx_finish_error_processing(trx);
 
-		return(NULL);
+		return;
 	}
 
 	if (lock_print_waits) {			
@@ -1125,23 +1151,19 @@ trx_finish_rollback_off_kernel(
 	send reply messages to them */
 
 	trx->que_state = TRX_QUE_RUNNING;
-
-	next_thr = NULL;
+	
 	while (sig != NULL) {
 		next_sig = UT_LIST_GET_NEXT(signals, sig);
 
 		if (sig->type == TRX_SIG_TOTAL_ROLLBACK) {
 
-			ut_a(next_thr == NULL);
-			next_thr = trx_sig_reply(sig);
+			trx_sig_reply(sig, next_thr);
 
 			trx_sig_remove(trx, sig);
 		}
 
 		sig = next_sig;
 	}
-
-	return(next_thr);
 }
 
 /*************************************************************************
@@ -1174,6 +1196,7 @@ trx_rollback_step(
 	que_thr_t*	thr)	/* in: query thread */
 {
 	roll_node_t*	node;
+	ibool		success;
 	ulint		sig_no;
 	trx_savept_t*	savept;
 	
@@ -1200,13 +1223,19 @@ trx_rollback_step(
 
 		/* Send a rollback signal to the transaction */
 
-		trx_sig_send(thr_get_trx(thr), sig_no, TRX_SIG_SELF,
-					thr, savept);
+		success = trx_sig_send(thr_get_trx(thr),
+					sig_no, TRX_SIG_SELF,
+					thr, savept, NULL);
 
 		thr->state = QUE_THR_SIG_REPLY_WAIT;
 		
 		mutex_exit(&kernel_mutex);
 
+		if (!success) {
+			/* Error in delivering the rollback signal */
+			que_thr_handle_error(thr, DB_ERROR, NULL, 0);
+		}
+
 		return(NULL);
 	}
 
diff --git a/innobase/trx/trx0trx.c b/innobase/trx/trx0trx.c
index 54993465f26..335e1f69228 100644
--- a/innobase/trx/trx0trx.c
+++ b/innobase/trx/trx0trx.c
@@ -895,15 +895,18 @@ trx_assign_read_view(
 /********************************************************************
 Commits a transaction. NOTE that the kernel mutex is temporarily released. */
 static
-que_thr_t*
+void
 trx_handle_commit_sig_off_kernel(
 /*=============================*/
-					/* out: next query thread to run */
-	trx_t*		trx)		/* in: transaction */
+	trx_t*		trx,		/* in: transaction */
+	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_sig_t*	sig;
 	trx_sig_t*	next_sig;
-	que_thr_t*	next_thr = NULL;
 	
 #ifdef UNIV_SYNC_DEBUG
 	ut_ad(mutex_own(&kernel_mutex));
@@ -925,8 +928,7 @@ trx_handle_commit_sig_off_kernel(
 
 		if (sig->type == TRX_SIG_COMMIT) {
 
-			ut_a(next_thr == NULL);
-			next_thr = trx_sig_reply(sig);
+			trx_sig_reply(sig, next_thr);
 			trx_sig_remove(trx, sig);
 		}
 
@@ -934,8 +936,6 @@ trx_handle_commit_sig_off_kernel(
 	}
 
 	trx->que_state = TRX_QUE_RUNNING;
-
-	return(next_thr);
 }
 
 /***************************************************************
@@ -997,6 +997,39 @@ trx_lock_wait_to_suspended(
 	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. */
@@ -1076,10 +1109,11 @@ trx_sig_is_compatible(
 /********************************************************************
 Sends a signal to a trx object. */
 
-que_thr_t*
+ibool
 trx_sig_send(
 /*=========*/
-					/* out: next query thread to run */
+					/* 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
@@ -1087,8 +1121,14 @@ trx_sig_send(
 	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
+	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;
@@ -1098,7 +1138,14 @@ trx_sig_send(
 	ut_ad(mutex_own(&kernel_mutex));
 #endif /* UNIV_SYNC_DEBUG */
 
-	ut_a(trx_sig_is_compatible(trx, type, sender));
+	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 */
 
@@ -1132,6 +1179,11 @@ trx_sig_send(
 									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
@@ -1146,10 +1198,10 @@ trx_sig_send(
 
 	if (UT_LIST_GET_FIRST(trx->signals) == sig) {
 	
-		return(trx_sig_start_handle(trx));
+		trx_sig_start_handle(trx, next_thr);
 	}
 
-	return(NULL);
+	return(TRUE);
 }
 
 /********************************************************************
@@ -1171,18 +1223,27 @@ trx_end_signal_handling(
 	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. */
 
-que_thr_t*
+void
 trx_sig_start_handle(
 /*=================*/
-				/* out: next query thread to run, or NULL */
-	trx_t*		trx)	/* in: trx 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 */
 {
-	que_thr_t*	next_thr = NULL;
 	trx_sig_t*	sig;
 	ulint		type;
 loop:
@@ -1198,7 +1259,7 @@ loop:
 
 		trx_end_signal_handling(trx);
 	
-		return(next_thr);
+		return;
 	}
 
 	if (trx->conc_state == TRX_NOT_STARTED) {
@@ -1214,13 +1275,23 @@ loop:
 		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(NULL);
+		return;
 	}
 
 	if (trx->handling_signals == FALSE) {
@@ -1234,19 +1305,30 @@ loop:
 
 	if (type == TRX_SIG_COMMIT) {
 
-		next_thr = trx_handle_commit_sig_off_kernel(trx);
+		trx_handle_commit_sig_off_kernel(trx, next_thr);
 
 	} else if ((type == TRX_SIG_TOTAL_ROLLBACK)
-				|| (type == TRX_SIG_ROLLBACK_TO_SAVEPT)
-				|| (type == TRX_SIG_ERROR_OCCURRED)) {
+				|| (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(trx_rollback(trx, sig));
+		return;
 
 	} else if (type == TRX_SIG_BREAK_EXECUTION) {
 
-		next_thr = trx_sig_reply(sig);
+		trx_sig_reply(sig, next_thr);
 		trx_sig_remove(trx, sig);
 	} else {
 		ut_error;
@@ -1259,14 +1341,17 @@ loop:
 Send the reply message when a signal in the queue of the trx has been
 handled. */
 
-que_thr_t*
+void
 trx_sig_reply(
 /*==========*/
-					/* out: next query thread to run */
-	trx_sig_t*	sig)		/* in: signal */
+	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;
-	que_thr_t*	next_thr = NULL;
+	trx_t*	receiver_trx;
 
 	ut_ad(sig);
 #ifdef UNIV_SYNC_DEBUG
@@ -1280,13 +1365,13 @@ trx_sig_reply(
 
 		UT_LIST_REMOVE(reply_signals, receiver_trx->reply_signals,
 									sig);
-		next_thr = que_thr_end_wait(sig->receiver);
+		ut_ad(receiver_trx->sess->state != SESS_ERROR);
+									
+		que_thr_end_wait(sig->receiver, next_thr);
 
 		sig->receiver = NULL;
 
 	}
-
-	return(next_thr);
 }
 
 /********************************************************************
@@ -1342,6 +1427,7 @@ trx_commit_step(
 {
 	commit_node_t*	node;
 	que_thr_t*	next_thr;
+	ibool		success;
 	
 	node = thr->run_node;
 
@@ -1356,15 +1442,22 @@ trx_commit_step(
 
 		node->state = COMMIT_NODE_WAIT;
 
+		next_thr = NULL;
+		
 		thr->state = QUE_THR_SIG_REPLY_WAIT;
 
 		/* Send the commit signal to the transaction */
 		
-		next_thr = trx_sig_send(thr_get_trx(thr), TRX_SIG_COMMIT,
-					TRX_SIG_SELF, thr, NULL);
-
+		success = trx_sig_send(thr_get_trx(thr), TRX_SIG_COMMIT,
+					TRX_SIG_SELF, thr, NULL, &next_thr);
+		
 		mutex_exit(&kernel_mutex);
 
+		if (!success) {
+			/* Error in delivering the commit signal */
+			que_thr_handle_error(thr, DB_ERROR, NULL, 0);
+		}
+
 		return(next_thr);
 	}
 
diff --git a/innobase/usr/usr0sess.c b/innobase/usr/usr0sess.c
index cc016f2b823..359c1552421 100644
--- a/innobase/usr/usr0sess.c
+++ b/innobase/usr/usr0sess.c
@@ -37,6 +37,8 @@ sess_open(void)
 #endif /* UNIV_SYNC_DEBUG */
 	sess = mem_alloc(sizeof(sess_t));
 
+	sess->state = SESS_ACTIVE;
+
 	sess->trx = trx_create(sess);
 
 	UT_LIST_INIT(sess->graphs);