Preserve identity for deep wrapping (bug 610390, r=mrbkap, a=b8).

js/src/xpconnect/src/xpcforwards.h

@@ -83,6 +83,7 @@ class XPCNativeScriptableSharedMap;
 class XPCWrappedNativeProtoMap;
 class XPCNativeWrapperMap;
 class WrappedNative2WrapperMap;
+class JSObject2JSObjectMap;
 
 class nsXPCComponents;
 class nsXPCComponents_Interfaces;

js/src/xpconnect/src/xpcjsruntime.cpp

@@ -240,6 +240,12 @@ ContextCallback(JSContext *cx, uintN operation)
     return JS_TRUE;
 }
 
+xpc::CompartmentPrivate::~CompartmentPrivate()
+{
+    if (waiverWrapperMap)
+        delete waiverWrapperMap;
+}
+
 static JSBool
 CompartmentCallback(JSContext *cx, JSCompartment *compartment, uintN op)
 {
@@ -545,6 +551,27 @@ DoDeferredRelease(nsTArray<T> &array)
     }
 }
 
+static JSDHashOperator
+SweepWaiverWrappers(JSDHashTable *table, JSDHashEntryHdr *hdr,
+                    uint32 number, void *arg)
+{
+    JSObject *key = ((JSObject2JSObjectMap::Entry *)hdr)->key;
+    JSObject *value = ((JSObject2JSObjectMap::Entry *)hdr)->value;
+    if(IsAboutToBeFinalized(key) || IsAboutToBeFinalized(value))
+        return JS_DHASH_REMOVE;
+    return JS_DHASH_NEXT;
+}
+
+static PLDHashOperator
+SweepCompartment(nsCStringHashKey& aKey, JSCompartment *compartment, void *aClosure)
+{
+    xpc::CompartmentPrivate *priv = (xpc::CompartmentPrivate *)
+        JS_GetCompartmentPrivate((JSContext *)aClosure, compartment);
+    if (priv->waiverWrapperMap)
+        priv->waiverWrapperMap->Enumerate(SweepWaiverWrappers, nsnull);
+    return PL_DHASH_NEXT;
+}
+
 // static
 JSBool XPCJSRuntime::GCCallback(JSContext *cx, JSGCStatus status)
 {
@@ -597,9 +624,14 @@ JSBool XPCJSRuntime::GCCallback(JSContext *cx, JSGCStatus status)
                         Enumerate(WrappedJSDyingJSObjectFinder, &data);
                 }
 
-                // Find dying scopes...
+                // Find dying scopes.
                 XPCWrappedNativeScope::FinishedMarkPhaseOfGC(cx, self);
 
+                // Sweep compartments.
+                self->GetCompartmentMap().EnumerateRead(
+                    (XPCCompartmentMap::EnumReadFunction)
+                    SweepCompartment, cx);
+
                 self->mDoingFinalization = JS_TRUE;
                 break;
             }

js/src/xpconnect/src/xpcmaps.cpp

@@ -763,3 +763,18 @@ WrappedNative2WrapperMap::AddLink(JSObject* wrappedObject, Link* oldLink)
 }
 
 /***************************************************************************/
+// implement JSObject2JSObjectMap...
+
+struct JSDHashTableOps
+JSObject2JSObjectMap::sOps = {
+    JS_DHashAllocTable,
+    JS_DHashFreeTable,
+    JS_DHashVoidPtrKeyStub,
+    JS_DHashMatchEntryStub,
+    JS_DHashMoveEntryStub,
+    JS_DHashClearEntryStub,
+    JS_DHashFinalizeStub,
+    nsnull
+};
+
+/***************************************************************************/

js/src/xpconnect/src/xpcmaps.h

@@ -710,4 +710,80 @@ private:
     JSDHashTable *mTable;
 };
 
+class JSObject2JSObjectMap
+{
+    static struct JSDHashTableOps sOps;
+
+public:
+    struct Entry : public JSDHashEntryHdr
+    {
+        JSObject* key;
+        JSObject* value;
+    };
+
+    static JSObject2JSObjectMap* newMap(int size)
+    {
+        JSObject2JSObjectMap* map = new JSObject2JSObjectMap(size);
+        if(map && map->mTable)
+            return map;
+        delete map;
+        return nsnull;
+    }
+
+    inline JSObject* Find(JSObject* key)
+    {
+        NS_PRECONDITION(key, "bad param");
+        Entry* entry = (Entry*)
+            JS_DHashTableOperate(mTable, key, JS_DHASH_LOOKUP);
+        if(JS_DHASH_ENTRY_IS_FREE(entry))
+            return nsnull;
+        return entry->value;
+    }
+
+    // Note: If the entry already exists, return the old value.
+    inline JSObject* Add(JSObject *key, JSObject *value)
+    {
+        NS_PRECONDITION(key,"bad param");
+        Entry* entry = (Entry*)
+            JS_DHashTableOperate(mTable, key, JS_DHASH_ADD);
+        if(!entry)
+            return nsnull;
+        if(entry->key)
+            return entry->value;
+        entry->key = key;
+        entry->value = value;
+        return value;
+    }
+
+    inline void Remove(JSObject* key)
+    {
+        NS_PRECONDITION(key,"bad param");
+        JS_DHashTableOperate(mTable, key, JS_DHASH_REMOVE);
+    }
+
+    inline uint32 Count() {return mTable->entryCount;}
+
+    inline uint32 Enumerate(JSDHashEnumerator f, void *arg)
+    {
+        return JS_DHashTableEnumerate(mTable, f, arg);
+    }
+
+    ~JSObject2JSObjectMap()
+    {
+        if(mTable)
+            JS_DHashTableDestroy(mTable);
+    }
+
+private:
+    JSObject2JSObjectMap(int size)
+    {
+        mTable = JS_NewDHashTable(&sOps, nsnull, sizeof(Entry), size);
+    }
+
+    JSObject2JSObjectMap(); // no implementation
+
+private:
+    JSDHashTable *mTable;
+};
+
 #endif /* xpcmaps_h___ */

js/src/xpconnect/src/xpcprivate.h

@@ -240,6 +240,7 @@ void DEBUG_CheckWrapperThreadSafety(const XPCWrappedNative* wrapper);
 #define XPC_NATIVE_JSCLASS_MAP_SIZE         32
 #define XPC_THIS_TRANSLATOR_MAP_SIZE         8
 #define XPC_NATIVE_WRAPPER_MAP_SIZE         16
+#define XPC_WRAPPER_MAP_SIZE                16
 
 /***************************************************************************/
 // data declarations...
@@ -323,7 +324,7 @@ typedef nsDataHashtableMT<nsISupportsHashKey, JSCompartment *> XPCMTCompartmentM
 typedef nsDataHashtable<xpc::PtrAndPrincipalHashKey, JSCompartment *> XPCCompartmentMap;
 
 /***************************************************************************/
-// useful macros...
+// Useful macros...
 
 #define XPC_STRING_GETTER_BODY(dest, src) \
     NS_ENSURE_ARG_POINTER(dest); \
@@ -4484,22 +4485,28 @@ struct CompartmentPrivate
     : key(key),
       ptr(nsnull),
       wantXrays(wantXrays),
-      cycleCollectionEnabled(cycleCollectionEnabled)
+      cycleCollectionEnabled(cycleCollectionEnabled),
+      waiverWrapperMap(nsnull)
   {
   }
+
   CompartmentPrivate(nsISupports *ptr, bool wantXrays, bool cycleCollectionEnabled)
     : key(nsnull),
       ptr(ptr),
       wantXrays(wantXrays),
-      cycleCollectionEnabled(cycleCollectionEnabled)
+      cycleCollectionEnabled(cycleCollectionEnabled),
+      waiverWrapperMap(nsnull)
   {
   }
 
+  ~CompartmentPrivate();
+
   // NB: key and ptr are mutually exclusive.
   nsAutoPtr<PtrAndPrincipalHashKey> key;
   nsCOMPtr<nsISupports> ptr;
   bool wantXrays;
   bool cycleCollectionEnabled;
+  JSObject2JSObjectMap *waiverWrapperMap;
 };
 
 inline bool

js/src/xpconnect/tests/chrome/Makefile.in

@@ -58,6 +58,7 @@ _CHROME_FILES = \
 		test_bug517163.xul \
 		test_bug571849.xul \
 		test_bug601803.xul \
+		test_bug610390.xul \
 		$(NULL)
 
 # Disabled until this test gets updated to test the new proxy based

js/src/xpconnect/tests/chrome/test_bug610390.xul

@@ -0,0 +1,34 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
+<?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
+                 type="text/css"?>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=610390
+-->
+<window title="Mozilla Bug 610390"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+  <script type="application/javascript"
+          src="chrome://mochikit/content/MochiKit/packed.js"></script>
+  <script type="application/javascript"
+          src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+
+  <!-- test results are displayed in the html:body -->
+  <body xmlns="http://www.w3.org/1999/xhtml">
+    <iframe type="content"
+      src="data:text/html,&lt;script&gt;var x=3&lt;/script&gt;"
+      onload="go()"
+      id="ifr">
+    </iframe>
+  </body>
+
+  <!-- test code goes here -->
+  <script type="application/javascript"><![CDATA[
+    SimpleTest.waitForExplicitFinish();
+
+    function go() {
+      var w = $('ifr').contentWindow;
+      is(w.wrappedJSObject, w.wrappedJSObject, "wrappedJSObject identity not maintained");
+      SimpleTest.finish();
+    }
+  ]]></script>
+</window>

js/src/xpconnect/wrappers/WrapperFactory.cpp

@@ -48,6 +48,7 @@
 #include "XPCWrapper.h"
 
 #include "xpcprivate.h"
+#include "xpcmaps.h"
 
 namespace xpc {
 
@@ -307,10 +308,33 @@ WrapperFactory::WaiveXrayAndWrap(JSContext *cx, jsval *vp)
     obj = GetCurrentOuter(cx, obj);
 
     {
-        js::SwitchToCompartment sc(cx, obj->compartment());
-        obj = JSWrapper::New(cx, obj, NULL, obj->getGlobal(), &WaiveXrayWrapperWrapper);
-        if (!obj)
-            return false;
+        // See if we already have a waiver wrapper for this object.
+        CompartmentPrivate *priv =
+            (CompartmentPrivate *)JS_GetCompartmentPrivate(cx, obj->compartment());
+        JSObject *wobj = nsnull;
+        if (priv && priv->waiverWrapperMap)
+            wobj = priv->waiverWrapperMap->Find(obj);
+
+        // No wrapper yet, make one.
+        if (!wobj) {
+            js::SwitchToCompartment sc(cx, obj->compartment());
+            wobj = JSWrapper::New(cx, obj, NULL, obj->getGlobal(), &WaiveXrayWrapperWrapper);
+            if (!wobj)
+                return false;
+
+            // Add the new wrapper so we find it next time.
+            if (priv) {
+                if (!priv->waiverWrapperMap) {
+                    priv->waiverWrapperMap = JSObject2JSObjectMap::newMap(XPC_WRAPPER_MAP_SIZE);
+                    if (!priv->waiverWrapperMap)
+                        return false;
+                }
+                if (!priv->waiverWrapperMap->Add(obj, wobj))
+                    return false;
+            }
+        }
+
+        obj = wobj;
     }
 
     *vp = OBJECT_TO_JSVAL(obj);