From 95b6826ed47b0341d21b631712c65f895b4c38e0 Mon Sep 17 00:00:00 2001
From: Kent Hansen <kent.hansen@nokia.com>
Date: Thu, 12 Jul 2012 21:54:41 +0200
Subject: statemachine: Make signal transition registration thread-safe

Since Qt's connections are thread-safe, QStateMachine's plumbing
around them should be thread-safe too.

Change-Id: I8ae91c2edc2d32ca4ed4258b71e5da22de30ed91
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>
---
 src/corelib/statemachine/qstatemachine.cpp | 10 ++++++++++
 src/corelib/statemachine/qstatemachine_p.h |  1 +
 2 files changed, 11 insertions(+)

(limited to 'src')

diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index ec4f3dea4c..72f4a123e6 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -1739,6 +1739,7 @@ void QStateMachinePrivate::registerSignalTransition(QSignalTransition *transitio
     while (meta->method(signalIndex).attributes() & QMetaMethod::Cloned)
         --signalIndex;
 
+    connectionsMutex.lock();
     QVector<int> &connectedSignalIndexes = connections[sender];
     if (connectedSignalIndexes.size() <= signalIndex)
         connectedSignalIndexes.resize(signalIndex+1);
@@ -1757,6 +1758,8 @@ void QStateMachinePrivate::registerSignalTransition(QSignalTransition *transitio
         }
     }
     ++connectedSignalIndexes[signalIndex];
+    connectionsMutex.unlock();
+
     QSignalTransitionPrivate::get(transition)->signalIndex = signalIndex;
     QSignalTransitionPrivate::get(transition)->originalSignalIndex = originalSignalIndex;
 #ifdef QSTATEMACHINE_DEBUG
@@ -1777,6 +1780,8 @@ void QStateMachinePrivate::unregisterSignalTransition(QSignalTransition *transit
     if (!sender || (sender->thread() != q->thread()))
         return;
     QSignalTransitionPrivate::get(transition)->signalIndex = -1;
+
+    connectionsMutex.lock();
     QVector<int> &connectedSignalIndexes = connections[sender];
     Q_ASSERT(connectedSignalIndexes.size() > signalIndex);
     Q_ASSERT(connectedSignalIndexes.at(signalIndex) != 0);
@@ -1790,6 +1795,7 @@ void QStateMachinePrivate::unregisterSignalTransition(QSignalTransition *transit
         if (sum == 0)
             connections.remove(sender);
     }
+    connectionsMutex.unlock();
 }
 
 void QStateMachinePrivate::unregisterAllTransitions()
@@ -1878,7 +1884,11 @@ void QStateMachinePrivate::handleFilteredEvent(QObject *watched, QEvent *event)
 void QStateMachinePrivate::handleTransitionSignal(QObject *sender, int signalIndex,
                                                   void **argv)
 {
+#ifndef QT_NO_DEBUG
+    connectionsMutex.lock();
     Q_ASSERT(connections[sender].at(signalIndex) != 0);
+    connectionsMutex.unlock();
+#endif
     const QMetaObject *meta = sender->metaObject();
     QMetaMethod method = meta->method(signalIndex);
     QList<QByteArray> parameterTypes = method.parameterTypes();
diff --git a/src/corelib/statemachine/qstatemachine_p.h b/src/corelib/statemachine/qstatemachine_p.h
index f3291e7d35..9e1f425779 100644
--- a/src/corelib/statemachine/qstatemachine_p.h
+++ b/src/corelib/statemachine/qstatemachine_p.h
@@ -257,6 +257,7 @@ public:
     QSignalEventGenerator *signalEventGenerator;
 
     QHash<const QObject*, QVector<int> > connections;
+    QMutex connectionsMutex;
 #ifndef QT_NO_STATEMACHINE_EVENTFILTER
     QHash<QObject*, QHash<QEvent::Type, int> > qobjectEvents;
 #endif
-- 
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