let's see if serializing (via a mutex) access to kservicetypetrader helps with those kservicetypetrader related crashes i'm seeing constantly go away

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=768454

abstractrunner.cpp

@@ -18,11 +18,15 @@
  */
 
 #include "abstractrunner.h"
-#include "searchcontext.h"
+
+#include <QMutex>
+#include <QMutexLocker>
 
 #include <KDebug>
 #include <KServiceTypeTrader>
 
+#include "searchcontext.h"
+
 namespace Plasma
 {
 
@@ -147,6 +151,14 @@ void AbstractRunner::setPriority(Priority priority)
     d->priority = priority;
 }
 
+QMutex serviceTypeTraderLock;
+
+KService::List AbstractRunner::serviceQuery(const QString &serviceType, const QString &constraint) const
+{
+    QMutexLocker lock(&serviceTypeTraderLock);
+    return KServiceTypeTrader::self()->query(serviceType, constraint);
+}
+
 void AbstractRunner::exec(Plasma::SearchMatch *action)
 {
     Q_UNUSED(action)

abstractrunner.h

@@ -24,6 +24,7 @@
 #include <QtCore/QStringList>
 
 #include <KDE/KConfigGroup>
+#include <KDE/KService>
 
 #include <plasma/plasma_export.h>
 #include <plasma/searchmatch.h>
@@ -193,6 +194,18 @@ class PLASMA_EXPORT AbstractRunner : public QObject
          */
         void setPriority(Priority newPriority);
 
+        /**
+         * A thread safe (blocking) method to do queries of installed Services
+         *
+         * @arg serviceType a service type like "Plasma/Applet" or "KFilePlugin"
+         * @arg constraint a constraint to limie the the choices returned.
+         * @see KServiceTypeTrader::query(const QString&, const QString&)
+         *
+         * @return a list of services that satisfy the query.
+         */
+        KService::List serviceQuery(const QString &serviceType,
+                                    const QString &constraint = QString()) const;
+
     private:
         class Private;
         Private* const d;