QDBusMetaTypeId: don't cache the result of qMetaTypeId<>() in static ints

There's not much point in caching the result of qMetaTypeId<>,
because it's already internally memoised.

In addition, the code that initialised the static int caches wasn't
protected against concurrent access under the assumption that the
operations performed were thread-safe.

That is true for most of them, but not for the stores to the static ints,
which race against each other:

   // Thread A               // Thread B
   r1 = initialized /*=false*/
                             r1 = initialized /*=false*/
   r2 = qMetaTypeId<...>();
                             r2 = qMetaTypeId<...>();
   message = r2;             message = r2; // race, ditto for all other ints

To fix, turn the ints into inline functions that just call the respective
qMetaTypeId<>() function.

Change-Id: I5aa80c624872c3867232abc26ffdcde70cd54022
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/dbus/qdbusabstractadaptor.cpp b/src/dbus/qdbusabstractadaptor.cpp
index e8236dd90a..d17f10f422 100644
--- a/src/dbus/qdbusabstractadaptor.cpp
+++ b/src/dbus/qdbusabstractadaptor.cpp
@@ -304,7 +304,7 @@ void QDBusAdaptorConnector::relay(QObject *senderObj, int lastSignalIdx, void **
         // qDBusParametersForMethod has already complained
         return;
     if (inputCount + 1 != types.count() ||
-        types.at(inputCount) == QDBusMetaTypeId::message) {
+        types.at(inputCount) == QDBusMetaTypeId::message()) {
         // invalid signal signature
         // qDBusParametersForMethod has not yet complained about this one
         qWarning("QDBusAbstractAdaptor: Cannot relay signal %s::%s",