Make reference counting in activeQt container multi-processor safe

Use InterlockedIncrement() and InterlockedDecrement() to implement
reference couting in activeQt container to make it multi-processor safe.

Change-Id: Ibe7daab69c27117bb3e35c10ba273bccd29afc69
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>

2 files changed, 21 insertions, 18 deletions

diff --git a/src/activeqt/container/qaxbase.cpp b/src/activeqt/container/qaxbase.cpp
index d83c12b..7f9c3c4 100644
--- a/src/activeqt/container/qaxbase.cpp
+++ b/src/activeqt/container/qaxbase.cpp
@@ -290,15 +290,15 @@ public:
     // IUnknown
     unsigned long __stdcall AddRef()
     {
-        return ref++;
+        return InterlockedIncrement(&ref);
     }
     unsigned long __stdcall Release()
     {
-        if (!--ref) {
+        LONG refCount = InterlockedDecrement(&ref);
+        if (!refCount)
             delete this;
-            return 0;
-        }
-        return ref;
+
+        return refCount;
     }
     HRESULT __stdcall QueryInterface(REFIID riid, void **ppvObject)
     {
@@ -538,7 +538,7 @@ public:
     QMap<DISPID, QByteArray> props;
 
     QAxBase *combase;
-    long ref;
+    LONG ref;
 };
 
 /*
@@ -4216,14 +4216,17 @@ public:
         AddRef();
         return S_OK;
     }
-    unsigned long __stdcall AddRef() { return ++ref; }
+    unsigned long __stdcall AddRef()
+    {
+        return InterlockedIncrement(&ref);
+    }
     unsigned long __stdcall Release()
     {
-        if (!--ref) {
+        LONG refCount = InterlockedDecrement(&ref);
+        if (!refCount)
             delete this;
-            return 0;
-        }
-        return ref;
+
+        return refCount;
     }
 
     HRESULT __stdcall Read(LPCOLESTR name, VARIANT *var, IErrorLog *)
@@ -4250,7 +4253,7 @@ public:
     QAxBase::PropertyBag map;
 
 private:
-    unsigned long ref;
+    LONG ref;
 };
 
 /*!
diff --git a/src/activeqt/container/qaxscript.cpp b/src/activeqt/container/qaxscript.cpp
index c5504ce..7166998 100644
--- a/src/activeqt/container/qaxscript.cpp
+++ b/src/activeqt/container/qaxscript.cpp
@@ -113,7 +113,7 @@ protected:
     
 private:
     QAxScript *script;
-    unsigned long ref;
+    LONG ref;
 };
 
 /*
@@ -129,7 +129,7 @@ QAxScriptSite::QAxScriptSite(QAxScript *s)
 */
 ULONG WINAPI QAxScriptSite::AddRef()
 {
-    return ++ref;
+    return InterlockedIncrement(&ref);
 }
 
 /*
@@ -137,11 +137,11 @@ ULONG WINAPI QAxScriptSite::AddRef()
 */
 ULONG WINAPI QAxScriptSite::Release()
 {
-    if (!--ref) {
+    LONG refCount = InterlockedDecrement(&ref);
+    if (!refCount)
         delete this;
-        return 0;
-    }
-    return ref;
+
+    return refCount;
 }
 
 /*