Phonon/ds9: fix a potential dead-lock found by user

This is following merge request 878. A customer was able to get a dead-
lock when calling at the same time RenderFile and enumerating the audio
devices. We now have a global mutex for that.

4 files changed, 12 insertions, 1 deletions

diff --git a/src/3rdparty/phonon/ds9/backend.cpp b/src/3rdparty/phonon/ds9/backend.cpp
index 6007020..6ed0145 100644
--- a/src/3rdparty/phonon/ds9/backend.cpp
+++ b/src/3rdparty/phonon/ds9/backend.cpp
@@ -64,6 +64,11 @@ namespace Phonon
             ::CoUninitialize();
         }
 
+        QMutex *Backend::directShowMutex()
+        {
+            return &qobject_cast<Backend*>(qt_plugin_instance())->m_directShowMutex;
+        }
+
         QObject *Backend::createObject(BackendInterface::Class c, QObject *parent, const QList<QVariant> &args)
         {
             switch (c)
@@ -131,6 +136,7 @@ namespace Phonon
 
         QList<int> Backend::objectDescriptionIndexes(Phonon::ObjectDescriptionType type) const
         {
+            QMutexLocker locker(&m_directShowMutex);
             QList<int> ret;
 
             switch(type)
@@ -204,6 +210,7 @@ namespace Phonon
 
         QHash<QByteArray, QVariant> Backend::objectDescriptionProperties(Phonon::ObjectDescriptionType type, int index) const
         {
+            QMutexLocker locker(&m_directShowMutex);
             QHash<QByteArray, QVariant> ret;
             switch (type)
             {
diff --git a/src/3rdparty/phonon/ds9/backend.h b/src/3rdparty/phonon/ds9/backend.h
index ad638f2..9b2c2a2 100644
--- a/src/3rdparty/phonon/ds9/backend.h
+++ b/src/3rdparty/phonon/ds9/backend.h
@@ -23,6 +23,7 @@ along with this library.  If not, see <http://www.gnu.org/licenses/>.
 #include <phonon/phononnamespace.h>
 
 #include <QtCore/QList>
+#include <QtCore/QMutex>
 
 #include "compointer.h"
 #include "backendnode.h"
@@ -63,6 +64,8 @@ namespace Phonon
 
             Filter getAudioOutputFilter(int index) const;
 
+            static QMutex *Backend::directShowMutex();
+
         Q_SIGNALS:
             void objectDescriptionChanged(ObjectDescriptionType);
 
@@ -74,6 +77,7 @@ namespace Phonon
             };
             mutable QVector<AudioMoniker> m_audioOutputs;
             mutable QVector<CLSID> m_audioEffects;
+            mutable QMutex m_directShowMutex;
         };
     }
 }
diff --git a/src/3rdparty/phonon/ds9/mediaobject.cpp b/src/3rdparty/phonon/ds9/mediaobject.cpp
index 39fcaa0..579517f 100644
--- a/src/3rdparty/phonon/ds9/mediaobject.cpp
+++ b/src/3rdparty/phonon/ds9/mediaobject.cpp
@@ -177,6 +177,7 @@ namespace Phonon
 
         void WorkerThread::handleTask()
         {
+            QMutexLocker locker(Backend::directShowMutex());
             {
                 QMutexLocker locker(&m_mutex);
                 if (m_finished || m_queue.isEmpty()) {
diff --git a/src/3rdparty/phonon/ds9/qpin.cpp b/src/3rdparty/phonon/ds9/qpin.cpp
index 8653db9..b4afd10 100644
--- a/src/3rdparty/phonon/ds9/qpin.cpp
+++ b/src/3rdparty/phonon/ds9/qpin.cpp
@@ -543,7 +543,6 @@ namespace Phonon
 
         FILTER_STATE QPin::filterState() const
         {
-            QMutexLocker locker(&m_mutex);
             FILTER_STATE fstate = State_Stopped;
             m_parent->GetState(0, &fstate);
             return fstate;