re-fix bug 166147 - autoinitialize mRefCnt to 0 for more efficient constructors

r=dougt, sr=jag, this time including some CSS stuff that has 31-bit refcounts.

content/html/style/src/nsCSSRule.cpp

@@ -75,14 +75,16 @@ void nsCSSRule::operator delete(void* ptr)
 }
 
 nsCSSRule::nsCSSRule(void)
-  : mSheet(nsnull),
+  : mRefCnt(0),
+    mSheet(nsnull),
     mParentRule(nsnull)
 {
   NS_INIT_ISUPPORTS();
 }
 
 nsCSSRule::nsCSSRule(const nsCSSRule& aCopy)
-  : mSheet(aCopy.mSheet),
+  : mRefCnt(0),
+    mSheet(aCopy.mSheet),
     mParentRule(aCopy.mParentRule)
 {
   NS_INIT_ISUPPORTS();

content/html/style/src/nsCSSStyleSheet.cpp

@@ -1767,6 +1767,7 @@ MOZ_DECL_CTOR_COUNTER(CSSStyleSheetImpl)
 
 CSSStyleSheetImpl::CSSStyleSheetImpl()
   : nsICSSStyleSheet(),
+    mRefCnt(0),
     mTitle(), 
     mMedia(nsnull),
     mFirstChild(nsnull), 
@@ -1788,6 +1789,7 @@ CSSStyleSheetImpl::CSSStyleSheetImpl()
 
 CSSStyleSheetImpl::CSSStyleSheetImpl(const CSSStyleSheetImpl& aCopy)
   : nsICSSStyleSheet(),
+    mRefCnt(0),
     mTitle(aCopy.mTitle), 
     mMedia(nsnull),
     mFirstChild(nsnull), 

content/html/style/src/nsHTMLCSSStyleSheet.cpp

@@ -297,6 +297,7 @@ void HTMLCSSStyleSheetImpl::operator delete(void* ptr)
 
 HTMLCSSStyleSheetImpl::HTMLCSSStyleSheetImpl()
   : nsIHTMLCSSStyleSheet(),
+    mRefCnt(0),
     mURL(nsnull),
     mDocument(nsnull),
     mFirstLineRule(nsnull),

content/html/style/src/nsHTMLStyleSheet.cpp

@@ -858,6 +858,7 @@ void HTMLStyleSheetImpl::operator delete(void* ptr)
 
 HTMLStyleSheetImpl::HTMLStyleSheetImpl(void)
   : nsIHTMLStyleSheet(),
+    mRefCnt(0),
     mURL(nsnull),
     mDocument(nsnull),
     mLinkRule(nsnull),

content/xul/content/src/nsXULAttributes.cpp

@@ -610,7 +610,7 @@ NS_IMPL_ADDREF(nsXULAttributes);
 nsrefcnt
 nsXULAttributes::Release()
 {
-    mRefCnt--;
+    --mRefCnt;
     NS_LOG_RELEASE(this, mRefCnt, "nsXULAttributes");
     if (mRefCnt == 0) {
         mRefCnt = 1;            // stabilize (necessary for this class?)

content/xul/content/src/nsXULElement.h

@@ -208,10 +208,10 @@ public:
                                  nsIURI* aDocumentURI,
                                  nsISupportsArray* aNodeInfos) = 0;
 
-    void AddRef() { mRefCnt++; };
+    void AddRef() { ++mRefCnt; };
     void Release() 
     { 
-        mRefCnt--; 
+        --mRefCnt; 
         if (mRefCnt == 0) 
             delete this; 
     };

layout/style/nsCSSRule.cpp

@@ -75,14 +75,16 @@ void nsCSSRule::operator delete(void* ptr)
 }
 
 nsCSSRule::nsCSSRule(void)
-  : mSheet(nsnull),
+  : mRefCnt(0),
+    mSheet(nsnull),
     mParentRule(nsnull)
 {
   NS_INIT_ISUPPORTS();
 }
 
 nsCSSRule::nsCSSRule(const nsCSSRule& aCopy)
-  : mSheet(aCopy.mSheet),
+  : mRefCnt(0),
+    mSheet(aCopy.mSheet),
     mParentRule(aCopy.mParentRule)
 {
   NS_INIT_ISUPPORTS();

layout/style/nsCSSStyleSheet.cpp

@@ -1767,6 +1767,7 @@ MOZ_DECL_CTOR_COUNTER(CSSStyleSheetImpl)
 
 CSSStyleSheetImpl::CSSStyleSheetImpl()
   : nsICSSStyleSheet(),
+    mRefCnt(0),
     mTitle(), 
     mMedia(nsnull),
     mFirstChild(nsnull), 
@@ -1788,6 +1789,7 @@ CSSStyleSheetImpl::CSSStyleSheetImpl()
 
 CSSStyleSheetImpl::CSSStyleSheetImpl(const CSSStyleSheetImpl& aCopy)
   : nsICSSStyleSheet(),
+    mRefCnt(0),
     mTitle(aCopy.mTitle), 
     mMedia(nsnull),
     mFirstChild(nsnull), 

layout/style/nsHTMLCSSStyleSheet.cpp

@@ -297,6 +297,7 @@ void HTMLCSSStyleSheetImpl::operator delete(void* ptr)
 
 HTMLCSSStyleSheetImpl::HTMLCSSStyleSheetImpl()
   : nsIHTMLCSSStyleSheet(),
+    mRefCnt(0),
     mURL(nsnull),
     mDocument(nsnull),
     mFirstLineRule(nsnull),

layout/style/nsHTMLStyleSheet.cpp

@@ -858,6 +858,7 @@ void HTMLStyleSheetImpl::operator delete(void* ptr)
 
 HTMLStyleSheetImpl::HTMLStyleSheetImpl(void)
   : nsIHTMLStyleSheet(),
+    mRefCnt(0),
     mURL(nsnull),
     mDocument(nsnull),
     mLinkRule(nsnull),

view/src/nsViewManager.cpp

@@ -432,7 +432,7 @@ nsrefcnt nsViewManager::Release(void)
       delete this;
       return 0;
     }
-  mRefCnt--;
+  --mRefCnt;
   return mRefCnt;
 }
 

xpcom/glue/nsISupportsImpl.h

@@ -85,7 +85,26 @@ extern "C" NS_COM void NS_CheckThreadSafe(void* owningThread,
 
 #endif // !(defined(NS_DEBUG) && defined(NS_MT_SUPPORTED))
 
-////////////////////////////////////////////////////////////////////////////////
+class nsAutoRefCnt {
+
+ public:
+    nsAutoRefCnt() : mValue(0) {}
+    nsAutoRefCnt(nsrefcnt aValue) : mValue(aValue) {}
+
+    // only support prefix increment/decrement
+    nsrefcnt operator++() { return ++mValue; }
+    nsrefcnt operator--() { return --mValue; }
+    
+    nsrefcnt operator=(nsrefcnt aValue) { return (mValue = aValue); }
+    operator nsrefcnt() const { return mValue; }
+ private:
+    // do not define these to enforce the faster prefix notation
+    nsrefcnt operator++(int);
+    nsrefcnt operator--(int);
+    nsrefcnt mValue;
+};
+
+///////////////////////////////////////////////////////////////////////////////
 
 /**
  * Declare the reference count variable and the implementations of the
@@ -99,7 +118,7 @@ public:                                                                       \
   NS_IMETHOD_(nsrefcnt) AddRef(void);                                         \
   NS_IMETHOD_(nsrefcnt) Release(void);                                        \
 protected:                                                                    \
-  nsrefcnt mRefCnt;                                                           \
+  nsAutoRefCnt mRefCnt;                                                       \
   NS_DECL_OWNINGTHREAD                                                        \
 public:
 
@@ -110,7 +129,7 @@ public:
  * Initialize the reference count variable. Add this to each and every
  * constructor you implement.
  */
-#define NS_INIT_ISUPPORTS() (mRefCnt = 0, NS_IMPL_OWNINGTHREAD())
+#define NS_INIT_ISUPPORTS() (NS_IMPL_OWNINGTHREAD())
 
 /**
  * Use this macro to implement the AddRef method for a given <i>_class</i>

xpfe/bootstrap/nsNativeAppSupportBase.cpp

@@ -145,7 +145,7 @@ nsNativeAppSupportBase::CreateSplashScreen( nsISplashScreen **splash ) {
 // Standard implementations of AddRef/Release/QueryInterface.
 NS_IMETHODIMP_(nsrefcnt)
 nsNativeAppSupportBase::AddRef() {
-    mRefCnt++;
+    ++mRefCnt;
     return mRefCnt;
 }