Merge branch '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.6-integration

* '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-1:
  Fix a race condition with QtDBus blocking for replies.
  QtDBus: Debug message update

4 files changed, 84 insertions, 35 deletions

diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index 6cb4924..0f49dcc 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -523,7 +523,7 @@ qDBusSignalFilter(DBusConnection *connection, DBusMessage *message, void *data)
         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 
     QDBusMessage amsg = QDBusMessagePrivate::fromDBusMessage(message);
-    qDBusDebug() << d << "got message:" << amsg;
+    qDBusDebug() << d << "got message (signal):" << amsg;
 
     return d->handleMessage(amsg) ?
         DBUS_HANDLER_RESULT_HANDLED :
@@ -1687,15 +1687,31 @@ static void qDBusResultReceived(DBusPendingCall *pending, void *user_data)
 void QDBusConnectionPrivate::waitForFinished(QDBusPendingCallPrivate *pcall)
 {
     Q_ASSERT(pcall->pending);
-    QDBusDispatchLocker locker(PendingCallBlockAction, this);
-    q_dbus_pending_call_block(pcall->pending);
-    // QDBusConnectionPrivate::processFinishedCall() is called automatically
+    Q_ASSERT(!pcall->autoDelete);
+    //Q_ASSERT(pcall->mutex.isLocked()); // there's no such function
+
+    if (pcall->waitingForFinished) {
+        // another thread is already waiting
+        pcall->waitForFinishedCondition.wait(&pcall->mutex);
+    } else {
+        pcall->waitingForFinished = true;
+        pcall->mutex.unlock();
+
+        {
+            QDBusDispatchLocker locker(PendingCallBlockAction, this);
+            q_dbus_pending_call_block(pcall->pending);
+            // QDBusConnectionPrivate::processFinishedCall() is called automatically
+        }
+        pcall->mutex.lock();
+    }
 }
 
 void QDBusConnectionPrivate::processFinishedCall(QDBusPendingCallPrivate *call)
 {
     QDBusConnectionPrivate *connection = const_cast<QDBusConnectionPrivate *>(call->connection);
 
+    QMutexLocker locker(&call->mutex);
+
     QDBusMessage &msg = call->replyMessage;
     if (call->pending) {
         // decode the message
@@ -1725,6 +1741,12 @@ void QDBusConnectionPrivate::processFinishedCall(QDBusPendingCallPrivate *call)
             qDBusDebug() << "Deliver failed!";
     }
 
+    if (call->pending)
+        q_dbus_pending_call_unref(call->pending);
+    call->pending = 0;
+
+    locker.unlock();
+
     // Are there any watchers?
     if (call->watcherHelper)
         call->watcherHelper->emitSignals(msg, call->sentMessage);
@@ -1732,12 +1754,10 @@ void QDBusConnectionPrivate::processFinishedCall(QDBusPendingCallPrivate *call)
     if (msg.type() == QDBusMessage::ErrorMessage)
         emit connection->callWithCallbackFailed(QDBusError(msg), call->sentMessage);
 
-    if (call->pending)
-        q_dbus_pending_call_unref(call->pending);
-    call->pending = 0;
-
-    if (call->autoDelete)
+    if (call->autoDelete) {
+        Q_ASSERT(!call->waitingForFinished); // can't wait on a call with autoDelete!
         delete call;
+    }
 }
 
 int QDBusConnectionPrivate::send(const QDBusMessage& message)
@@ -1879,17 +1899,14 @@ QDBusPendingCallPrivate *QDBusConnectionPrivate::sendWithReplyAsync(const QDBusM
 {
     if (isServiceRegisteredByThread(message.service())) {
         // special case for local calls
-        QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate;
-        pcall->sentMessage = message;
+        QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate(message, this);
         pcall->replyMessage = sendWithReplyLocal(message);
-        pcall->connection = this;
 
         return pcall;
     }
 
     checkThread();
-    QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate;
-    pcall->sentMessage = message;
+    QDBusPendingCallPrivate *pcall = new QDBusPendingCallPrivate(message, this);
     pcall->ref = 0;
 
     QDBusError error;
@@ -1913,7 +1930,6 @@ QDBusPendingCallPrivate *QDBusConnectionPrivate::sendWithReplyAsync(const QDBusM
             q_dbus_message_unref(msg);
 
             pcall->pending = pending;
-            pcall->connection = this;
             q_dbus_pending_call_set_notify(pending, qDBusResultReceived, pcall, 0);
 
             return pcall;
diff --git a/src/dbus/qdbuspendingcall.cpp b/src/dbus/qdbuspendingcall.cpp
index 3db5d9f..86b585d 100644
--- a/src/dbus/qdbuspendingcall.cpp
+++ b/src/dbus/qdbuspendingcall.cpp
@@ -208,6 +208,8 @@ void QDBusPendingCallPrivate::setMetaTypes(int count, const int *types)
 
 void QDBusPendingCallPrivate::checkReceivedSignature()
 {
+    // MUST BE CALLED WITH A LOCKED MUTEX!
+
     if (replyMessage.type() == QDBusMessage::InvalidMessage)
         return;                 // not yet finished - no message to
                                 // validate against
@@ -230,6 +232,8 @@ void QDBusPendingCallPrivate::checkReceivedSignature()
 
 void QDBusPendingCallPrivate::waitForFinished()
 {
+    QMutexLocker locker(&mutex);
+
     if (replyMessage.type() != QDBusMessage::InvalidMessage)
         return;                 // already finished
 
@@ -310,7 +314,11 @@ QDBusPendingCall &QDBusPendingCall::operator=(const QDBusPendingCall &other)
 
 bool QDBusPendingCall::isFinished() const
 {
-    return !d || (d->replyMessage.type() != QDBusMessage::InvalidMessage);
+    if (!d)
+        return true; // considered finished
+
+    QMutexLocker locker(&d->mutex);
+    return d->replyMessage.type() != QDBusMessage::InvalidMessage;
 }
 
 void QDBusPendingCall::waitForFinished()
@@ -329,7 +337,10 @@ void QDBusPendingCall::waitForFinished()
 */
 bool QDBusPendingCall::isValid() const
 {
-    return d ? d->replyMessage.type() == QDBusMessage::ReplyMessage : false;
+    if (!d)
+        return false;
+    QMutexLocker locker(&d->mutex);
+    return d->replyMessage.type() == QDBusMessage::ReplyMessage;
 }
 
 /*!
@@ -343,7 +354,10 @@ bool QDBusPendingCall::isValid() const
 */
 bool QDBusPendingCall::isError() const
 {
-    return d ? d->replyMessage.type() == QDBusMessage::ErrorMessage : true;
+    if (!d)
+        return true; // considered finished and an error
+    QMutexLocker locker(&d->mutex);
+    return d->replyMessage.type() == QDBusMessage::ErrorMessage;
 }
 
 /*!
@@ -356,8 +370,10 @@ bool QDBusPendingCall::isError() const
 */
 QDBusError QDBusPendingCall::error() const
 {
-    if (d)
+    if (d) {
+        QMutexLocker locker(&d->mutex);
         return d->replyMessage;
+    }
 
     // not connected, return an error
     QDBusError err = QDBusError(QDBusError::Disconnected,
@@ -378,7 +394,10 @@ QDBusError QDBusPendingCall::error() const
 */
 QDBusMessage QDBusPendingCall::reply() const
 {
-    return d ? d->replyMessage : QDBusMessage::createError(error());
+    if (!d)
+        return QDBusMessage::createError(error());
+    QMutexLocker locker(&d->mutex);
+    return d->replyMessage;
 }
 
 #if 0
@@ -439,9 +458,8 @@ QDBusPendingCall QDBusPendingCall::fromCompletedCall(const QDBusMessage &msg)
     QDBusPendingCallPrivate *d = 0;
     if (msg.type() == QDBusMessage::ErrorMessage ||
         msg.type() == QDBusMessage::ReplyMessage) {
-        d = new QDBusPendingCallPrivate;
+        d = new QDBusPendingCallPrivate(QDBusMessage(), 0);
         d->replyMessage = msg;
-        d->connection = 0;
     }
 
     return QDBusPendingCall(d);
@@ -471,9 +489,10 @@ QDBusPendingCallWatcher::QDBusPendingCallWatcher(const QDBusPendingCall &call, Q
     : QObject(*new QDBusPendingCallWatcherPrivate, parent), QDBusPendingCall(call)
 {
     if (d) {                    // QDBusPendingCall::d
+        QMutexLocker locker(&d->mutex);
         if (!d->watcherHelper) {
             d->watcherHelper = new QDBusPendingCallWatcherHelper;
-            if (isFinished()) {
+            if (d->replyMessage.type() != QDBusMessage::InvalidMessage) {
                 // cause a signal emission anyways
                 QMetaObject::invokeMethod(d->watcherHelper, "finished", Qt::QueuedConnection);
             }
diff --git a/src/dbus/qdbuspendingcall_p.h b/src/dbus/qdbuspendingcall_p.h
index 641c397..c3aed53 100644
--- a/src/dbus/qdbuspendingcall_p.h
+++ b/src/dbus/qdbuspendingcall_p.h
@@ -57,6 +57,8 @@
 #include <qshareddata.h>
 #include <qpointer.h>
 #include <qlist.h>
+#include <qmutex.h>
+#include <qwaitcondition.h>
 
 #include "qdbusmessage.h"
 #include "qdbus_symbols_p.h"
@@ -71,24 +73,35 @@ class QDBusConnectionPrivate;
 class QDBusPendingCallPrivate: public QSharedData
 {
 public:
-    QDBusMessage sentMessage;
-    QDBusMessage replyMessage;
-//    QDBusMessage pendingReplyMessage; // used in the local loop
-    QDBusPendingCallWatcherHelper *watcherHelper;
-    DBusPendingCall *pending;
-    QDBusConnectionPrivate *connection;
+    // {
+    //     set only during construction:
+    const QDBusMessage sentMessage;
+    QDBusConnectionPrivate * const connection;
 
-    QString expectedReplySignature;
-    int expectedReplyCount;
-
-    // for the callback
+    // for the callback mechanism (see setReplyCallback and QDBusConnectionPrivate::sendWithReplyAsync)
     QPointer<QObject> receiver;
     QList<int> metaTypes;
     int methodIdx;
 
     bool autoDelete;
+    // }
+
+    mutable QMutex mutex;
+    QWaitCondition waitForFinishedCondition;
+
+    // {
+    //    protected by the mutex above:
+    QDBusPendingCallWatcherHelper *watcherHelper;
+    QDBusMessage replyMessage;
+    DBusPendingCall *pending;
+    volatile bool waitingForFinished;
+
+    QString expectedReplySignature;
+    int expectedReplyCount;
+    // }
 
-    QDBusPendingCallPrivate() : watcherHelper(0), pending(0), autoDelete(false)
+    QDBusPendingCallPrivate(const QDBusMessage &sent, QDBusConnectionPrivate *connection)
+        : sentMessage(sent), connection(connection), autoDelete(false), watcherHelper(0), pending(0), waitingForFinished(false)
     { }
     ~QDBusPendingCallPrivate();
     bool setReplyCallback(QObject *target, const char *member);
diff --git a/src/dbus/qdbuspendingreply.cpp b/src/dbus/qdbuspendingreply.cpp
index b492660..1df47f4 100644
--- a/src/dbus/qdbuspendingreply.cpp
+++ b/src/dbus/qdbuspendingreply.cpp
@@ -252,7 +252,7 @@ void QDBusPendingReplyData::assign(const QDBusPendingCall &other)
 
 void QDBusPendingReplyData::assign(const QDBusMessage &message)
 {
-    d = new QDBusPendingCallPrivate; // drops the reference to the old one
+    d = new QDBusPendingCallPrivate(QDBusMessage(), 0); // drops the reference to the old one
     d->replyMessage = message;
 }
 
@@ -271,6 +271,7 @@ QVariant QDBusPendingReplyData::argumentAt(int index) const
 void QDBusPendingReplyData::setMetaTypes(int count, const int *types)
 {
     Q_ASSERT(d);
+    QMutexLocker locker(&d->mutex);
     d->setMetaTypes(count, types);
     d->checkReceivedSignature();
 }