Introduce Q_APPLICATION_STATIC

QObjects must be deleted if the QCoreApplication is being destroyed.
This was previously done by implementing custom code in qtbase and
other modules. So unify it and introduce a Q_APPLICATION_STATIC,
based on the Q_GLOBAL_STATIC, which centralises the logic.

Since we still have a few remaining living QObjects,
this comes in handy to fix those as well.

Task-number: QTBUG-84234
Change-Id: I3040a2280ff56291f2b1c39948c06a23597865c4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 5 insertions, 36 deletions

diff --git a/src/network/kernel/qhostinfo.cpp b/src/network/kernel/qhostinfo.cpp
index fdf2844447..6f508fb59b 100644
--- a/src/network/kernel/qhostinfo.cpp
+++ b/src/network/kernel/qhostinfo.cpp
@@ -43,6 +43,7 @@
 #include "qhostinfo_p.h"
 #include <qplatformdefs.h>
 
+#include "QtCore/qapplicationstatic.h"
 #include "QtCore/qscopedpointer.h"
 #include <qabstracteventdispatcher.h>
 #include <qcoreapplication.h>
@@ -99,24 +100,7 @@ std::pair<OutputIt1, OutputIt2> separate_if(InputIt first, InputIt last, OutputI
     return std::make_pair(dest1, dest2);
 }
 
-QHostInfoLookupManager* theHostInfoLookupManager()
-{
-    static QHostInfoLookupManager* theManager = nullptr;
-    static QBasicMutex theMutex;
-
-    const QMutexLocker locker(&theMutex);
-    if (theManager == nullptr) {
-        theManager = new QHostInfoLookupManager();
-        Q_ASSERT(QCoreApplication::instance());
-        QObject::connect(QCoreApplication::instance(), &QCoreApplication::destroyed, [] {
-            const QMutexLocker locker(&theMutex);
-            delete theManager;
-            theManager = nullptr;
-        });
-    }
-
-    return theManager;
-}
+Q_APPLICATION_STATIC(QHostInfoLookupManager, theHostInfoLookupManager)
 
 }
 
diff --git a/src/network/kernel/qhostinfo_unix.cpp b/src/network/kernel/qhostinfo_unix.cpp
index 9b0a2ee669..3ccf8b217b 100644
--- a/src/network/kernel/qhostinfo_unix.cpp
+++ b/src/network/kernel/qhostinfo_unix.cpp
@@ -53,6 +53,8 @@
 #include <qfile.h>
 #include <private/qnet_unix_p.h>
 
+#include "QtCore/qapplicationstatic.h"
+
 #include <sys/types.h>
 #include <netdb.h>
 #include <arpa/inet.h>
@@ -157,24 +159,7 @@ LibResolv::LibResolv()
     }
 }
 
-LibResolv* libResolv()
-{
-    static LibResolv* theLibResolv = nullptr;
-    static QBasicMutex theMutex;
-
-    const QMutexLocker locker(&theMutex);
-    if (theLibResolv == nullptr) {
-        theLibResolv = new LibResolv();
-        Q_ASSERT(QCoreApplication::instance());
-        QObject::connect(QCoreApplication::instance(), &QCoreApplication::destroyed, [] {
-            const QMutexLocker locker(&theMutex);
-            delete theLibResolv;
-            theLibResolv = nullptr;
-        });
-    }
-
-    return theLibResolv;
-}
+Q_APPLICATION_STATIC(LibResolv, libResolv)
 
 static void resolveLibrary(LibResolvFeature f)
 {