/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sw=4 et tw=78:
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   John Bandhauer <jband@netscape.com> (original author)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/* Wrapper object for reflecting native xpcom objects into JavaScript. */

#include "xpcprivate.h"
#include "nsCRT.h"
#include "XPCNativeWrapper.h"

/***************************************************************************/

#ifdef XPC_CHECK_CLASSINFO_CLAIMS
static void DEBUG_CheckClassInfoClaims(XPCWrappedNative* wrapper);
#else
#define DEBUG_CheckClassInfoClaims(wrapper) ((void)0)
#endif

#ifdef XPC_CHECK_WRAPPER_THREADSAFETY
PRThread* XPCWrappedNative::gMainThread = nsnull;
#endif

#ifdef XPC_TRACK_WRAPPER_STATS
static int DEBUG_TotalWrappedNativeCount;
static int DEBUG_TotalLiveWrappedNativeCount;
static int DEBUG_TotalMaxWrappedNativeCount;
static int DEBUG_WrappedNativeWithProtoCount;
static int DEBUG_LiveWrappedNativeWithProtoCount;
static int DEBUG_MaxWrappedNativeWithProtoCount;
static int DEBUG_WrappedNativeNoProtoCount;
static int DEBUG_LiveWrappedNativeNoProtoCount;
static int DEBUG_MaxWrappedNativeNoProtoCount;
static int DEBUG_WrappedNativeTotalCalls;
static int DEBUG_WrappedNativeMethodCalls;
static int DEBUG_WrappedNativeGetterCalls;
static int DEBUG_WrappedNativeSetterCalls;
#define DEBUG_CHUNKS_TO_COUNT 4
static int DEBUG_WrappedNativeTearOffChunkCounts[DEBUG_CHUNKS_TO_COUNT+1];
static PRBool  DEBUG_DumpedWrapperStats;
#endif

#ifdef DEBUG
static void DEBUG_TrackNewWrapper(XPCWrappedNative* wrapper)
{
#ifdef XPC_CHECK_WRAPPERS_AT_SHUTDOWN
    if(wrapper->GetRuntime())
        wrapper->GetRuntime()->DEBUG_AddWrappedNative(wrapper);
    else
        NS_ERROR("failed to add wrapper");
#endif
#ifdef XPC_TRACK_WRAPPER_STATS
    DEBUG_TotalWrappedNativeCount++;
    DEBUG_TotalLiveWrappedNativeCount++;
    if(DEBUG_TotalMaxWrappedNativeCount < DEBUG_TotalLiveWrappedNativeCount)
        DEBUG_TotalMaxWrappedNativeCount = DEBUG_TotalLiveWrappedNativeCount;

    if(wrapper->HasProto())
    {
        DEBUG_WrappedNativeWithProtoCount++;
        DEBUG_LiveWrappedNativeWithProtoCount++;
        if(DEBUG_MaxWrappedNativeWithProtoCount < DEBUG_LiveWrappedNativeWithProtoCount)
            DEBUG_MaxWrappedNativeWithProtoCount = DEBUG_LiveWrappedNativeWithProtoCount;
    }
    else
    {
        DEBUG_WrappedNativeNoProtoCount++;
        DEBUG_LiveWrappedNativeNoProtoCount++;
        if(DEBUG_MaxWrappedNativeNoProtoCount < DEBUG_LiveWrappedNativeNoProtoCount)
            DEBUG_MaxWrappedNativeNoProtoCount = DEBUG_LiveWrappedNativeNoProtoCount;
    }
#endif
}

static void DEBUG_TrackDeleteWrapper(XPCWrappedNative* wrapper)
{
#ifdef XPC_CHECK_WRAPPERS_AT_SHUTDOWN
    if(wrapper->GetRuntime())
        wrapper->GetRuntime()->DEBUG_RemoveWrappedNative(wrapper);
    else
        NS_ERROR("failed to remove wrapper");
#endif
#ifdef XPC_TRACK_WRAPPER_STATS
    DEBUG_TotalLiveWrappedNativeCount--;
    if(wrapper->HasProto())
        DEBUG_LiveWrappedNativeWithProtoCount--;
    else
        DEBUG_LiveWrappedNativeNoProtoCount--;

    int extraChunkCount = wrapper->DEBUG_CountOfTearoffChunks() - 1;
    if(extraChunkCount > DEBUG_CHUNKS_TO_COUNT)
        extraChunkCount = DEBUG_CHUNKS_TO_COUNT;
    DEBUG_WrappedNativeTearOffChunkCounts[extraChunkCount]++;
#endif
}
static void DEBUG_TrackWrapperCall(XPCWrappedNative* wrapper,
                                   XPCWrappedNative::CallMode mode)
{
#ifdef XPC_TRACK_WRAPPER_STATS
    DEBUG_WrappedNativeTotalCalls++;
    switch(mode)
    {
        case XPCWrappedNative::CALL_METHOD:
            DEBUG_WrappedNativeMethodCalls++;
            break;
        case XPCWrappedNative::CALL_GETTER:
            DEBUG_WrappedNativeGetterCalls++;
            break;
        case XPCWrappedNative::CALL_SETTER:
            DEBUG_WrappedNativeSetterCalls++;
            break;
        default:
            NS_ERROR("bad value");
    }
#endif
}

static void DEBUG_TrackShutdownWrapper(XPCWrappedNative* wrapper)
{
#ifdef XPC_TRACK_WRAPPER_STATS
    if(!DEBUG_DumpedWrapperStats)
    {
        DEBUG_DumpedWrapperStats = PR_TRUE;
        printf("%d WrappedNatives were constructed. "
               "(%d w/ protos, %d w/o)\n",
               DEBUG_TotalWrappedNativeCount,
               DEBUG_WrappedNativeWithProtoCount,
               DEBUG_WrappedNativeNoProtoCount);

        printf("%d WrappedNatives max alive at one time. "
               "(%d w/ protos, %d w/o)\n",
               DEBUG_TotalMaxWrappedNativeCount,
               DEBUG_MaxWrappedNativeWithProtoCount,
               DEBUG_MaxWrappedNativeNoProtoCount);

        printf("%d WrappedNatives alive now. "
               "(%d w/ protos, %d w/o)\n",
               DEBUG_TotalLiveWrappedNativeCount,
               DEBUG_LiveWrappedNativeWithProtoCount,
               DEBUG_LiveWrappedNativeNoProtoCount);

        printf("%d calls to WrappedNatives. "
               "(%d methods, %d getters, %d setters)\n",
               DEBUG_WrappedNativeTotalCalls,
               DEBUG_WrappedNativeMethodCalls,
               DEBUG_WrappedNativeGetterCalls,
               DEBUG_WrappedNativeSetterCalls);

        printf("(wrappers / tearoffs): (");
        int i;
        for(i = 0; i < DEBUG_CHUNKS_TO_COUNT; i++)
        {
            printf("%d / %d, ",
                   DEBUG_WrappedNativeTearOffChunkCounts[i],
                   (i+1) * XPC_WRAPPED_NATIVE_TEAROFFS_PER_CHUNK);
        }
        printf("%d / more)\n", DEBUG_WrappedNativeTearOffChunkCounts[i]);
    }
#endif
}
#else
#define DEBUG_TrackNewWrapper(wrapper) ((void)0)
#define DEBUG_TrackDeleteWrapper(wrapper) ((void)0)
#define DEBUG_TrackWrapperCall(wrapper, mode) ((void)0)
#define DEBUG_TrackShutdownWrapper(wrapper) ((void)0)
#endif

/***************************************************************************/

// static
nsresult
XPCWrappedNative::GetNewOrUsed(XPCCallContext& ccx,
                               nsISupports* Object,
                               XPCWrappedNativeScope* Scope,
                               XPCNativeInterface* Interface,
                               XPCWrappedNative** resultWrapper)
{
    nsresult rv;

    NS_ASSERTION(!Scope->GetRuntime()->GetThreadRunningGC(), 
                 "XPCWrappedNative::GetNewOrUsed called during GC");

    nsCOMPtr<nsISupports> identity;
#ifdef XPC_IDISPATCH_SUPPORT
    // XXX This is done for the benefit of some warped COM implementations
    // where QI(IID_IUnknown, a.b) == QI(IID_IUnknown, a). If someone passes
    // in a pointer that hasn't been QI'd to IDispatch properly this could
    // create multiple wrappers for the same object, creating a fair bit of
    // confusion.
    PRBool isIDispatch = Interface->GetIID()->Equals(NSID_IDISPATCH);
    if(isIDispatch)
        identity = Object;
    else
#endif
        identity = do_QueryInterface(Object);

    if(!identity)
    {
        NS_ERROR("This XPCOM object fails in QueryInterface to nsISupports!");
        return NS_ERROR_FAILURE;
    }

    XPCLock* mapLock = Scope->GetRuntime()->GetMapLock();
    
    // We use an AutoMarkingPtr here because it is possible for JS gc to happen
    // after we have Init'd the wrapper but *before* we add it to the hashtable.
    // This would cause the mSet to get collected and we'd later crash. I've
    // *seen* this happen.
    AutoMarkingWrappedNativePtr wrapper(ccx);

    Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();
    {   // scoped lock
        XPCAutoLock lock(mapLock);
        wrapper = map->Find(identity);
        if(wrapper)
            wrapper->AddRef();
    }

    if(wrapper)
    {
        if(!wrapper->FindTearOff(ccx, Interface, JS_FALSE, &rv))
        {
            NS_RELEASE(wrapper);
            NS_ASSERTION(NS_FAILED(rv), "returning NS_OK on failure");
            return rv;
        }
        DEBUG_CheckWrapperThreadSafety(wrapper);
        *resultWrapper = wrapper;
        return NS_OK;
    }

    // There is a chance that the object wants to have the self-same JSObject
    // reflection regardless of the scope into which we are reflecting it.
    // Many DOM objects require this. The scriptable helper specifies this
    // in preCreate by indicating a 'parent' of a particular scope.
    //
    // To handle this we need to get the scriptable helper early and ask it.
    // It is possible that we will then end up forwarding this entire call
    // to this same function but with a different scope.

    // If we are making a wrapper for the nsIClassInfo interface then
    // We *don't* want to have it use the prototype meant for instances
    // of that class.
    JSBool isClassInfo = Interface->GetIID()->Equals(NS_GET_IID(nsIClassInfo));

    nsCOMPtr<nsIClassInfo> info;

    if(!isClassInfo)
        info = do_QueryInterface(identity);

#ifdef XPC_IDISPATCH_SUPPORT
    // If this is an IDispatch wrapper and it didn't give us a class info
    // we'll provide a default one
    if(isIDispatch && !info)
    {
        info = dont_AddRef(NS_STATIC_CAST(nsIClassInfo*,
                                          XPCIDispatchClassInfo::GetSingleton()));
    }
#endif

    XPCNativeScriptableCreateInfo sciProto;
    XPCNativeScriptableCreateInfo sciWrapper;

    // Gather scriptable create info if we are wrapping something
    // other than an nsIClassInfo object. We need to not do this for
    // nsIClassInfo objects because often nsIClassInfo implementations
    // are also nsIXPCScriptable helper implmentations, but the helper
    // code is obviously intended for the implementation of the class
    // described by the nsIClassInfo, not for the class info object
    // itself.
    if(!isClassInfo &&
       NS_FAILED(GatherScriptableCreateInfo(identity, info.get(),
                                            &sciProto, &sciWrapper)))
        return NS_ERROR_FAILURE;

    JSObject* parent = Scope->GetGlobalJSObject();

    jsval newParentVal = JSVAL_NULL;
    XPCMarkableJSVal newParentVal_markable(&newParentVal);
    AutoMarkingJSVal newParentVal_automarker(ccx, &newParentVal_markable);

    if(sciWrapper.GetFlags().WantPreCreate())
    {
        JSObject* plannedParent = parent;
        nsresult rv = sciWrapper.GetCallback()->PreCreate(identity, ccx,
                                                          parent, &parent);
        if(NS_FAILED(rv))
            return rv;

        NS_ASSERTION(!XPCNativeWrapper::IsNativeWrapper(ccx, parent),
                     "Parent should never be an XPCNativeWrapper here");

        if(parent != plannedParent)
        {
            XPCWrappedNativeScope* betterScope =
                XPCWrappedNativeScope::FindInJSObjectScope(ccx, parent);
            if(betterScope != Scope)
                return GetNewOrUsed(ccx, identity, betterScope, Interface,
                                    resultWrapper);

            newParentVal = OBJECT_TO_JSVAL(parent);
        }

        // Take the performance hit of checking the hashtable again in case
        // the preCreate call caused the wrapper to get created through some
        // interesting path (the DOM code tends to make this happen sometimes).

        {   // scoped lock
            XPCAutoLock lock(mapLock);
            wrapper = map->Find(identity);
            if(wrapper)
                wrapper->AddRef();
        }

        if(wrapper)
        {
            if(!wrapper->FindTearOff(ccx, Interface, JS_FALSE, &rv))
            {
                NS_RELEASE(wrapper);
                NS_ASSERTION(NS_FAILED(rv), "returning NS_OK on failure");
                return rv;
            }
            DEBUG_CheckWrapperThreadSafety(wrapper);
            *resultWrapper = wrapper;
            return NS_OK;
        }
    }

    AutoMarkingWrappedNativeProtoPtr proto(ccx);

    // If there is ClassInfo (and we are not building a wrapper for the
    // nsIClassInfo interface) then we use a wrapper that needs a prototype.

    // Note that the security check happens inside FindTearOff - after the
    // wrapper is actually created, but before JS code can see it.

    if(info && !isClassInfo)
    {
        proto = XPCWrappedNativeProto::GetNewOrUsed(ccx, Scope, info, &sciProto,
                                                    JS_FALSE);
        if(!proto)
            return NS_ERROR_FAILURE;

        wrapper = new XPCWrappedNative(identity, proto);
        if(!wrapper)
            return NS_ERROR_FAILURE;
    }
    else
    {
        AutoMarkingNativeSetPtr set(ccx);
        set = XPCNativeSet::GetNewOrUsed(ccx, nsnull, Interface, 0);

        if(!set)
            return NS_ERROR_FAILURE;

        wrapper = new XPCWrappedNative(identity, Scope, set);
        if(!wrapper)
            return NS_ERROR_FAILURE;

        DEBUG_ReportShadowedMembers(set, wrapper, nsnull);
    }

    NS_ADDREF(wrapper);

    NS_ASSERTION(!XPCNativeWrapper::IsNativeWrapper(ccx, parent),
                 "XPCNativeWrapper being used to parent XPCWrappedNative?");
    
    if(!wrapper->Init(ccx, parent, &sciWrapper))
    {
        NS_RELEASE(wrapper);
        return NS_ERROR_FAILURE;
    }

    if(!wrapper->FindTearOff(ccx, Interface, JS_FALSE, &rv))
    {
        // Second reference will be released by the FlatJSObject's finializer.
        wrapper->Release();
        NS_ASSERTION(NS_FAILED(rv), "returning NS_OK on failure");
        return rv;
    }

#if DEBUG_XPCNativeWrapper
    {
        char* s = wrapper->ToString(ccx);
        NS_ASSERTION(wrapper->GetFlatJSObject(), "eh?");
        printf("Created wrapped native %s, flat JSObject is %p\n",
               s, (void*)wrapper->GetFlatJSObject());
        if (s)
            JS_smprintf_free(s);
    }
#endif

    // Redundant wrapper must be killed outside of the map lock.
    XPCWrappedNative* wrapperToKill = nsnull;

    {   // scoped lock
        XPCAutoLock lock(mapLock);

        // Deal with the case where the wrapper got created as a side effect
        // of one of our calls out of this code (or on another thread).
        XPCWrappedNative* wrapper2 = map->Add(wrapper);
        if(!wrapper2)
        {
            NS_ERROR("failed to add our wrapper!");
            wrapperToKill = wrapper;
            wrapper = nsnull;
        }
        else if(wrapper2 != wrapper)
        {
            NS_ADDREF(wrapper2);
            wrapperToKill = wrapper;
            wrapper = wrapper2;
        }
    }

    if(wrapperToKill)
    {
        // Second reference will be released by the FlatJSObject's finializer.
        wrapperToKill->Release();
    }
    else if(wrapper)
    {
        // Our newly created wrapper is the one that we just added to the table.
        // All is well. Call PostCreate as necessary.
        XPCNativeScriptableInfo* si = wrapper->GetScriptableInfo();
        if(si && si->GetFlags().WantPostCreate())
        {
            si->GetCallback()->
                PostCreate(wrapper, ccx, wrapper->GetFlatJSObject());
        }
    }

    if(!wrapper)
        return NS_ERROR_FAILURE;

    DEBUG_CheckClassInfoClaims(wrapper);
    *resultWrapper = wrapper;
    return NS_OK;
}

// static
nsresult
XPCWrappedNative::GetUsedOnly(XPCCallContext& ccx,
                              nsISupports* Object,
                              XPCWrappedNativeScope* Scope,
                              XPCNativeInterface* Interface,
                              XPCWrappedNative** resultWrapper)
{
    NS_ASSERTION(Object, "XPCWrappedNative::GetUsedOnly was called with a null Object");
    nsCOMPtr<nsISupports> identity;
#ifdef XPC_IDISPATCH_SUPPORT
    // XXX See GetNewOrUsed for more info on this
    if(Interface->GetIID()->Equals(NSID_IDISPATCH))
        identity = Object;
    else
#endif
        identity = do_QueryInterface(Object);

    if(!identity)
    {
        NS_ERROR("This XPCOM object fails in QueryInterface to nsISupports!");
        return NS_ERROR_FAILURE;
    }

    XPCWrappedNative* wrapper;
    Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();

    {   // scoped lock
        XPCAutoLock lock(Scope->GetRuntime()->GetMapLock());
        wrapper = map->Find(identity);
        if(!wrapper)
        {
            *resultWrapper = nsnull;
            return NS_OK;
        }
        NS_ADDREF(wrapper);
    }

    nsresult rv;
    if(!wrapper->FindTearOff(ccx, Interface, JS_FALSE, &rv))
    {
        NS_RELEASE(wrapper);
        NS_ASSERTION(NS_FAILED(rv), "returning NS_OK on failure");
        return rv;
    }

    *resultWrapper = wrapper;
    return NS_OK;
}

// This ctor is used if this object will have a proto.
XPCWrappedNative::XPCWrappedNative(nsISupports* aIdentity,
                                   XPCWrappedNativeProto* aProto)
    : mMaybeProto(aProto),
      mSet(aProto->GetSet()),
      mFlatJSObject((JSObject*)JSVAL_ONE), // non-null to pass IsValid() test
      mScriptableInfo(nsnull),
      mNativeWrapper(nsnull)
{
    NS_ADDREF(mIdentity = aIdentity);

    NS_ASSERTION(mMaybeProto, "bad ctor param");
    NS_ASSERTION(mSet, "bad ctor param");

    DEBUG_TrackNewWrapper(this);
}

// This ctor is used if this object will NOT have a proto.
XPCWrappedNative::XPCWrappedNative(nsISupports* aIdentity,
                                   XPCWrappedNativeScope* aScope,
                                   XPCNativeSet* aSet)

    : mMaybeScope(TagScope(aScope)),
      mSet(aSet),
      mFlatJSObject((JSObject*)JSVAL_ONE), // non-null to pass IsValid() test
      mScriptableInfo(nsnull),
      mNativeWrapper(nsnull)
{
    NS_ADDREF(mIdentity = aIdentity);

    NS_ASSERTION(aScope, "bad ctor param");
    NS_ASSERTION(aSet, "bad ctor param");

    DEBUG_TrackNewWrapper(this);
}

XPCWrappedNative::~XPCWrappedNative()
{
    DEBUG_TrackDeleteWrapper(this);

    XPCWrappedNativeProto* proto = GetProto();

    if(mScriptableInfo &&
       (!HasProto() ||
        (proto && proto->GetScriptableInfo() != mScriptableInfo)))
    {
        delete mScriptableInfo;
    }

    Native2WrappedNativeMap* map = GetScope()->GetWrappedNativeMap();
    {   // scoped lock
        XPCAutoLock lock(GetRuntime()->GetMapLock());
        map->Remove(this);
    }

    if(mIdentity)
    {
        XPCJSRuntime* rt = GetRuntime();
        if(rt && rt->GetDeferReleases() && rt->GetDoingFinalization())
        {
            if(!rt->DeferredRelease(mIdentity))
            {
                NS_WARNING("Failed to append object for deferred release.");
                // XXX do we really want to do this???
                NS_RELEASE(mIdentity);
            }
        }
        else
        {
            NS_RELEASE(mIdentity);
        }
    }
}

// This is factored out so that it can be called publicly 
// static
nsresult 
XPCWrappedNative::GatherProtoScriptableCreateInfo(
                        nsIClassInfo* classInfo,
                        XPCNativeScriptableCreateInfo* sciProto)
{
    NS_ASSERTION(classInfo, "bad param");
    NS_ASSERTION(sciProto && !sciProto->GetCallback(), "bad param");

    nsCOMPtr<nsISupports> possibleHelper;
    nsresult rv = classInfo->GetHelperForLanguage(
                                    nsIProgrammingLanguage::JAVASCRIPT,
                                    getter_AddRefs(possibleHelper));
    if(NS_SUCCEEDED(rv) && possibleHelper)
    {
        nsCOMPtr<nsIXPCScriptable> helper(do_QueryInterface(possibleHelper));
        if(helper)
        {
            JSUint32 flags;
            rv = helper->GetScriptableFlags(&flags);
            if(NS_FAILED(rv))
                flags = 0;

            sciProto->SetCallback(helper);
            sciProto->SetFlags(flags);
        }
    }
    return NS_OK;
}

// static
nsresult
XPCWrappedNative::GatherScriptableCreateInfo(
                        nsISupports* obj,
                        nsIClassInfo* classInfo,
                        XPCNativeScriptableCreateInfo* sciProto,
                        XPCNativeScriptableCreateInfo* sciWrapper)
{
    NS_ASSERTION(sciProto   && !sciProto->GetCallback(), "bad param");
    NS_ASSERTION(sciWrapper && !sciWrapper->GetCallback(), "bad param");

    // Get the class scriptable helper (if present)
    if(classInfo)
    {
        GatherProtoScriptableCreateInfo(classInfo, sciProto);

        sciWrapper->SetCallback(sciProto->GetCallback());
        sciWrapper->SetFlags(sciProto->GetFlags());

        if(sciProto->GetFlags().DontAskInstanceForScriptable())
            return NS_OK;
    }

    // Do the same for the wrapper specific scriptable
    nsCOMPtr<nsIXPCScriptable> helper(do_QueryInterface(obj));
    if(helper)
    {
        JSUint32 flags;
        nsresult rv = helper->GetScriptableFlags(&flags);
        if(NS_FAILED(rv))
            flags = 0;

        sciWrapper->SetCallback(helper);
        sciWrapper->SetFlags(flags);

        // A whole series of assertions to catch bad uses of scriptable flags on
        // the siWrapper...

        NS_ASSERTION(!(sciWrapper->GetFlags().WantPreCreate() &&
                        !sciProto->GetFlags().WantPreCreate()),
                     "Can't set WANT_PRECREATE on an instance scriptable "
                     "without also setting it on the class scriptable");

        NS_ASSERTION(!(sciWrapper->GetFlags().DontEnumStaticProps() &&
                        !sciProto->GetFlags().DontEnumStaticProps() &&
                        sciProto->GetCallback() &&
                        !sciProto->GetFlags().DontSharePrototype()),
                     "Can't set DONT_ENUM_STATIC_PROPS on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");

        NS_ASSERTION(!(sciWrapper->GetFlags().DontEnumQueryInterface() &&
                        !sciProto->GetFlags().DontEnumQueryInterface() &&
                        sciProto->GetCallback() &&
                        !sciProto->GetFlags().DontSharePrototype()),
                     "Can't set DONT_ENUM_QUERY_INTERFACE on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");

        NS_ASSERTION(!(sciWrapper->GetFlags().DontAskInstanceForScriptable() &&
                        !sciProto->GetFlags().DontAskInstanceForScriptable()),
                     "Can't set DONT_ASK_INSTANCE_FOR_SCRIPTABLE on an instance scriptable "
                     "without also setting it on the class scriptable");

        NS_ASSERTION(!(sciWrapper->GetFlags().ClassInfoInterfacesOnly() &&
                        !sciProto->GetFlags().ClassInfoInterfacesOnly() &&
                        sciProto->GetCallback() &&
                        !sciProto->GetFlags().DontSharePrototype()),
                     "Can't set CLASSINFO_INTERFACES_ONLY on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");

        NS_ASSERTION(!(sciWrapper->GetFlags().AllowPropModsDuringResolve() &&
                        !sciProto->GetFlags().AllowPropModsDuringResolve() &&
                        sciProto->GetCallback() &&
                        !sciProto->GetFlags().DontSharePrototype()),
                     "Can't set ALLOW_PROP_MODS_DURING_RESOLVE on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");

        NS_ASSERTION(!(sciWrapper->GetFlags().AllowPropModsToPrototype() &&
                        !sciProto->GetFlags().AllowPropModsToPrototype() &&
                        sciProto->GetCallback() &&
                        !sciProto->GetFlags().DontSharePrototype()),
                     "Can't set ALLOW_PROP_MODS_TO_PROTOTYPE on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");

        NS_ASSERTION(!(sciWrapper->GetFlags().DontSharePrototype() &&
                        !sciProto->GetFlags().DontSharePrototype() &&
                        sciProto->GetCallback()),
                     "Can't set DONT_SHARE_PROTOTYPE on an instance scriptable "
                     "without also setting it on the class scriptable (if present and shared)");
    }

    return NS_OK;
}

JSBool
XPCWrappedNative::Init(XPCCallContext& ccx, JSObject* parent,
                       const XPCNativeScriptableCreateInfo* sci)
{
    // setup our scriptable info...

    if(sci->GetCallback())
    {
        if(HasProto())
        {
            XPCNativeScriptableInfo* siProto = GetProto()->GetScriptableInfo();
            if(siProto && siProto->GetCallback() == sci->GetCallback())
                mScriptableInfo = siProto;
        }
        if(!mScriptableInfo)
        {
            mScriptableInfo =
                XPCNativeScriptableInfo::Construct(ccx, sci);

            if(!mScriptableInfo)
                return JS_FALSE;

            // If we have a one-off proto, then it should share our scriptable.
            // This allows the proto's JSClass callbacks to do the right things
            // (like respecting the DONT_ENUM_STATIC_PROPS flag) w/o requiring
            // scriptable objects to have an nsIClassInfo.
            if(HasProto() && !HasSharedProto())
                GetProto()->SetScriptableInfo(mScriptableInfo);
        }
    }
    XPCNativeScriptableInfo* si = mScriptableInfo;

    // create our flatJSObject

    JSClass* jsclazz = si ? si->GetJSClass() : &XPC_WN_NoHelper_JSClass.base;

    NS_ASSERTION(jsclazz &&
                 jsclazz->name &&
                 jsclazz->flags &&
                 jsclazz->addProperty &&
                 jsclazz->delProperty &&
                 jsclazz->getProperty &&
                 jsclazz->setProperty &&
                 jsclazz->enumerate &&
                 jsclazz->resolve &&
                 jsclazz->convert &&
                 jsclazz->finalize, "bad class");

    JSObject* protoJSObject = HasProto() ?
                                GetProto()->GetJSProtoObject() :
                                GetScope()->GetPrototypeJSObject();

    mFlatJSObject = JS_NewObject(ccx, jsclazz, protoJSObject, parent);

    if(!mFlatJSObject)
        return JS_FALSE;

    // In the current JS engine JS_SetPrivate can't fail. But if it *did*
    // fail then we would not receive our finalizer call and would not be
    // able to properly cleanup. So, if it fails we null out mFlatJSObject
    // to indicate the invalid state of this object and return false. 
    if(!JS_SetPrivate(ccx, mFlatJSObject, this))
    {
        mFlatJSObject = nsnull;
        return JS_FALSE;
    }

    // Propagate the system flag from parent to child.
    if(JS_IsSystemObject(ccx, parent))
        JS_FlagSystemObject(ccx, mFlatJSObject);

    // This reference will be released when mFlatJSObject is finalized.
    // Since this reference will push the refcount to 2 it will also root
    // mFlatJSObject;
    NS_ASSERTION(1 == mRefCnt, "unexpected refcount value");
    NS_ADDREF(this);

    if(si && si->GetFlags().WantCreate() &&
       NS_FAILED(si->GetCallback()->Create(this, ccx, mFlatJSObject)))
    {
        return JS_FALSE;
    }

#ifdef XPC_CHECK_WRAPPER_THREADSAFETY
    if(!gMainThread)
        gMainThread = nsXPConnect::GetMainThread();

    mThread = PR_GetCurrentThread();

    if(HasProto() && GetProto()->ClassIsMainThreadOnly() && gMainThread != mThread)
        DEBUG_ReportWrapperThreadSafetyError(ccx,
            "MainThread only wrapper created on the wrong thread", this);
#endif

    return JS_TRUE;
}


NS_INTERFACE_MAP_BEGIN(XPCWrappedNative)
  NS_INTERFACE_MAP_ENTRY(nsIXPConnectWrappedNative)
  NS_INTERFACE_MAP_ENTRY(nsIXPConnectJSObjectHolder)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIXPConnectWrappedNative)
NS_INTERFACE_MAP_END_THREADSAFE

NS_IMPL_THREADSAFE_ADDREF(XPCWrappedNative)
NS_IMPL_THREADSAFE_RELEASE(XPCWrappedNative)

/*
 *  Wrapped Native lifetime management is messy!
 *
 *  - At creation we push the refcount to 2 (only one of which is owned by
 *    the native caller that caused the wrapper creation).
 *  - During the JS GC Mark phase we mark any wrapper with a refcount > 1.
 *  - The *only* thing that can make the wrapper get destroyed is the
 *    finalization of mFlatJSObject. And *that* should only happen if the only
 *    reference is the single extra (internal) reference we hold.
 *
 *  - The wrapper has a pointer to the nsISupports 'view' of the wrapped native
 *    object i.e... mIdentity. This is held until the wrapper's refcount goes
 *    to zero and the wrapper is released.
 *
 *  - The wrapper also has 'tearoffs'. It has one tearoff for each interface
 *    that is actually used on the native object. 'Used' means we have either
 *    needed to QueryInterface to verify the availability of that interface
 *    of that we've had to QueryInterface in order to actually make a call
 *    into the wrapped object via the pointer for the given interface.
 *
 *  - Each tearoff's 'mNative' member (if non-null) indicates one reference
 *    held by our wrapper on the wrapped native for the given interface
 *    associated with the tearoff. If we release that reference then we set
 *    the tearoff's 'mNative' to null.
 *
 *  - We use the occasion of the JavaScript GCCallback for the JSGC_MARK_END
 *    event to scan the tearoffs of all wrappers for non-null mNative members
 *    that represent unused references. We can tell that a given tearoff's
 *    mNative is unused by noting that no live XPCCallContexts hold a pointer
 *    to the tearoff.
 *
 *  - As a time/space tradeoff we may decide to not do this scanning on
 *    *every* JavaScript GC. We *do* want to do this *sometimes* because
 *    we want to allow for wrapped native's to do their own tearoff patterns.
 *    So, we want to avoid holding references to interfaces that we don't need.
 *    At the same time, we don't want to be bracketing every call into a
 *    wrapped native object with a QueryInterface/Release pair. And we *never*
 *    make a call into the object except via the correct interface for which
 *    we've QI'd.
 *
 *  - Each tearoff *can* have a mJSObject whose lazily resolved properties
 *    represent the methods/attributes/constants of that specific interface.
 *    This is optionally reflected into JavaScript as "foo.nsIFoo" when "foo"
 *    is the name of mFlatJSObject and "nsIFoo" is the name of the given
 *    interface associated with the tearoff. When we create the tearoff's
 *    mJSObject we set it's parent to be mFlatJSObject. This way we know that
 *    when mFlatJSObject get's collected there are no outstanding reachable
 *    tearoff mJSObjects. Note that we must clear the private of any lingering
 *    mJSObjects at this point because we have no guarentee of the *order* of
 *    finalization within a given gc cycle.
 */

void
XPCWrappedNative::FlatJSObjectFinalized(JSContext *cx, JSObject *obj)
{
    if(!IsValid())
        return;

    // Iterate the tearoffs and null out each of their JSObject's privates.
    // This will keep them from trying to access their pointers to the
    // dying tearoff object. We can safely assume that those remaining
    // JSObjects are about to be finalized too.

    XPCWrappedNativeTearOffChunk* chunk;
    for(chunk = &mFirstChunk; chunk; chunk = chunk->mNextChunk)
    {
        XPCWrappedNativeTearOff* to = chunk->mTearOffs;
        for(int i = XPC_WRAPPED_NATIVE_TEAROFFS_PER_CHUNK-1; i >= 0; i--, to++)
        {
            JSObject* jso = to->GetJSObject();
            if(jso)
            {
                NS_ASSERTION(JS_IsAboutToBeFinalized(cx, jso), "bad!");
                JS_SetPrivate(cx, jso, nsnull);
                to->JSObjectFinalized();
            }

            // We also need to release any native pointers held...
            nsISupports* obj = to->GetNative();
            if(obj)
            {
#ifdef XP_WIN
                // Try to detect free'd pointer
                NS_ASSERTION(*(int*)obj != 0xdddddddd, "bad pointer!");
                NS_ASSERTION(*(int*)obj != 0,          "bad pointer!");
#endif
                XPCJSRuntime* rt = GetRuntime();
                if(rt && rt->GetDeferReleases())
                {
                    if(!rt->DeferredRelease(obj))
                    {
                        NS_WARNING("Failed to append object for deferred release.");
                        // XXX do we really want to do this???
                        obj->Release();
                    }
                }
                else
                {
                    obj->Release();
                }
                to->SetNative(nsnull);
            }

            to->SetInterface(nsnull);
        }
    }

    //This makes IsValid return false from now on...
    mFlatJSObject = nsnull;

    NS_ASSERTION(mIdentity, "bad pointer!");
#ifdef XP_WIN
    // Try to detect free'd pointer
    NS_ASSERTION(*(int*)mIdentity != 0xdddddddd, "bad pointer!");
    NS_ASSERTION(*(int*)mIdentity != 0,          "bad pointer!");
#endif

    // Note that it's not safe to touch mNativeWrapper here since it's
    // likely that it has already been finalized.

    Release();
}

void
XPCWrappedNative::SystemIsBeingShutDown(XPCCallContext& ccx)
{
    DEBUG_TrackShutdownWrapper(this);

    if(!IsValid())
        return;

    // The long standing strategy is to leak some objects still held at shutdown.
    // The general problem is that propagating release out of xpconnect at
    // shutdown time causes a world of problems.

    // We leak mIdentity (see above).

    // short circuit future finalization
    JS_SetPrivate(ccx, mFlatJSObject, nsnull);
    mFlatJSObject = nsnull; // This makes 'IsValid()' return false.

    XPCWrappedNativeProto* proto = GetProto();

    if(HasProto())
        proto->SystemIsBeingShutDown(ccx);

    if(mScriptableInfo &&
       (!HasProto() ||
        (proto && proto->GetScriptableInfo() != mScriptableInfo)))
    {
        delete mScriptableInfo;
    }

    // cleanup the tearoffs...

    XPCWrappedNativeTearOffChunk* chunk;
    for(chunk = &mFirstChunk; chunk; chunk = chunk->mNextChunk)
    {
        XPCWrappedNativeTearOff* to = chunk->mTearOffs;
        for(int i = XPC_WRAPPED_NATIVE_TEAROFFS_PER_CHUNK-1; i >= 0; i--, to++)
        {
            if(to->GetJSObject())
            {
                JS_SetPrivate(ccx, to->GetJSObject(), nsnull);
#ifdef XPC_IDISPATCH_SUPPORT
                if(to->IsIDispatch())
                    delete to->GetIDispatchInfo();
#endif
                to->SetJSObject(nsnull);
            }
            // We leak the tearoff mNative
            // (for the same reason we leak mIdentity - see above).
            to->SetNative(nsnull);
            to->SetInterface(nsnull);
        }
    }

    if(mFirstChunk.mNextChunk)
    {
        delete mFirstChunk.mNextChunk;
        mFirstChunk.mNextChunk = nsnull;
    }
}

/***************************************************************************/

// static
nsresult
XPCWrappedNative::ReparentWrapperIfFound(XPCCallContext& ccx,
                                         XPCWrappedNativeScope* aOldScope,
                                         XPCWrappedNativeScope* aNewScope,
                                         JSObject* aNewParent,
                                         nsISupports* aCOMObj,
                                         XPCWrappedNative** aWrapper)
{
    XPCNativeInterface* iface =
        XPCNativeInterface::GetISupports(ccx);

    if(!iface)
        return NS_ERROR_FAILURE;

    nsresult rv;
    XPCWrappedNative* wrapper;

    rv = XPCWrappedNative::GetUsedOnly(ccx, aCOMObj, aOldScope, iface, &wrapper);
    if(NS_FAILED(rv))
        return rv;

    if(!wrapper || !wrapper->IsValid())
    {
        NS_IF_RELEASE(wrapper);
        *aWrapper = nsnull;
        return NS_OK;
    }

    if(aOldScope != aNewScope)
    {
        // Oh, so now we need to move the wrapper to a different scope.

        AutoMarkingWrappedNativeProtoPtr oldProto(ccx);
        AutoMarkingWrappedNativeProtoPtr newProto(ccx);

        if(wrapper->HasProto())
        {
            oldProto = wrapper->GetProto();
            XPCNativeScriptableCreateInfo ci(*oldProto->GetScriptableInfo());
            newProto =
                XPCWrappedNativeProto::GetNewOrUsed(ccx, aNewScope,
                                                    oldProto->GetClassInfo(),
                                                    &ci,
                                                    !oldProto->IsShared());
            if(!newProto)
            {
                NS_RELEASE(wrapper);
                return NS_ERROR_FAILURE;
            }
        }

        Native2WrappedNativeMap* oldMap = aOldScope->GetWrappedNativeMap();
        Native2WrappedNativeMap* newMap = aNewScope->GetWrappedNativeMap();

        {   // scoped lock
            XPCAutoLock lock(aOldScope->GetRuntime()->GetMapLock());

            // We only try to fixup the __proto__ JSObject if the wrapper
            // is directly using that of its XPCWrappedNativeProto.

            if(wrapper->HasProto() &&
               JS_GetPrototype(ccx, wrapper->GetFlatJSObject()) ==
               oldProto->GetJSProtoObject())
            {
                if(!JS_SetPrototype(ccx, wrapper->GetFlatJSObject(),
                                    newProto->GetJSProtoObject()))
                {
                    // this is bad, very bad
                    NS_ERROR("JS_SetPrototype failed");
                    NS_RELEASE(wrapper);
                    return NS_ERROR_FAILURE;
                }
            }
            else
            {
                NS_WARNING("Moving XPConnect wrappedNative to new scope, "
                           "but can't fixup __proto__");
            }

            oldMap->Remove(wrapper);

            if(wrapper->HasProto())
                wrapper->mMaybeProto = newProto;

            // If the wrapper has no scriptable or it has a non-shared
            // scriptable, then we don't need to mess with it.
            // Otherwise...

            if(wrapper->mScriptableInfo &&
               wrapper->mScriptableInfo == oldProto->GetScriptableInfo())
            {
                // The new proto had better have the same JSClass stuff as the
                // old one! We maintain a runtime wide unique map of this stuff.
                // So, if these don't match then the caller is doing something
                // bad here.

                NS_ASSERTION(
                     oldProto->GetScriptableInfo()->GetScriptableShared() ==
                     newProto->GetScriptableInfo()->GetScriptableShared(),
                    "Changing proto is also changing JSObject Classname or "
                    "helper's nsIXPScriptable flags. This is not allowed!");

                wrapper->mScriptableInfo = newProto->GetScriptableInfo();
            }

            NS_ASSERTION(!newMap->Find(wrapper), "wrapper already in new scope!");

            (void) newMap->Add(wrapper);
        }
    }

    // Now we can just fix up the parent and return the wrapper

    if(!JS_SetParent(ccx, wrapper->GetFlatJSObject(), aNewParent))
    {
        NS_RELEASE(wrapper);
        return NS_ERROR_FAILURE;
    }

    *aWrapper = wrapper;
    return NS_OK;
}

#define IS_WRAPPER_CLASS(clazz)                                               \
          ((clazz) == &XPC_WN_NoHelper_JSClass.base ||                        \
           (clazz)->getObjectOps == XPC_WN_GetObjectOpsNoCall ||              \
           (clazz)->getObjectOps == XPC_WN_GetObjectOpsWithCall)

#define IS_TEAROFF_CLASS(clazz)                                               \
          ((clazz) == &XPC_WN_Tearoff_JSClass)

// static
XPCWrappedNative*
XPCWrappedNative::GetWrappedNativeOfJSObject(JSContext* cx,
                                             JSObject* obj,
                                             JSObject* funobj,
                                             JSObject** pobj2,
                                             XPCWrappedNativeTearOff** pTearOff)
{
    NS_PRECONDITION(obj, "bad param");

    JSObject* cur;

    XPCWrappedNativeProto* proto = nsnull;
    nsIClassInfo* protoClassInfo = nsnull;

    // If we were passed a function object then we need to find the correct
    // wrapper out of those that might be in the callee obj's proto chain.

    if(funobj)
    {
        JSObject* funObjParent = JS_GetParent(cx, funobj);
        NS_ASSERTION(funObjParent, "funobj has no parent");

        JSClass* funObjParentClass = JS_GET_CLASS(cx, funObjParent);

        if(IS_PROTO_CLASS(funObjParentClass))
        {
            NS_ASSERTION(JS_GetParent(cx, funObjParent), "funobj's parent (proto) is global");
            proto = (XPCWrappedNativeProto*) JS_GetPrivate(cx, funObjParent);
            if(proto)
                protoClassInfo = proto->GetClassInfo();
        }
        else if(IS_WRAPPER_CLASS(funObjParentClass))
        {
            cur = funObjParent;
            goto return_wrapper;
        }
        else if(IS_TEAROFF_CLASS(funObjParentClass))
        {
            NS_ASSERTION(JS_GetParent(cx, funObjParent), "funobj's parent (tearoff) is global");
            cur = funObjParent;
            goto return_tearoff;
        }
        else
        {
            NS_ERROR("function object has parent of unknown class!");
            return nsnull;
        }
    }

    for(cur = obj; cur; cur = JS_GetPrototype(cx, cur))
    {
        // this is on two lines to make the compiler happy given the goto.
        JSClass* clazz;
        clazz = JS_GET_CLASS(cx, cur);

        if(IS_WRAPPER_CLASS(clazz))
        {
return_wrapper:
            XPCWrappedNative* wrapper =
                (XPCWrappedNative*) JS_GetPrivate(cx, cur);
            if(proto && proto != wrapper->GetProto() &&
               (proto->GetScope() != wrapper->GetScope() ||
                !protoClassInfo ||
                protoClassInfo != wrapper->GetProto()->GetClassInfo()))
                continue;
            if(pobj2)
                *pobj2 = cur;
            return wrapper;
        }

        if(IS_TEAROFF_CLASS(clazz))
        {
return_tearoff:
            XPCWrappedNative* wrapper =
                (XPCWrappedNative*) JS_GetPrivate(cx, JS_GetParent(cx,cur));
            if(proto && proto != wrapper->GetProto() &&
               (proto->GetScope() != wrapper->GetScope() ||
                !protoClassInfo ||
                protoClassInfo != wrapper->GetProto()->GetClassInfo()))
                continue;
            if(pobj2)
                *pobj2 = cur;
            XPCWrappedNativeTearOff* to =
                (XPCWrappedNativeTearOff*) JS_GetPrivate(cx, cur);
            if(!to)
                return nsnull;
            if(pTearOff)
                *pTearOff = to;
            return wrapper;
        }

        if(XPCNativeWrapper::IsNativeWrapperClass(clazz))
        {
            if(pobj2)
                *pobj2 = cur;

            return XPCNativeWrapper::GetWrappedNative(cx, cur);
        }
    }

    // If we didn't find a wrapper using the given funobj and obj, try
    // again with obj's outer object, if it's got one.

    JSClass *clazz = JS_GET_CLASS(cx, obj);

    if((clazz->flags & JSCLASS_IS_EXTENDED) &&
       ((JSExtendedClass*)clazz)->outerObject)
    {
        JSObject *outer = ((JSExtendedClass*)clazz)->outerObject(cx, obj);

        if(outer && outer != obj)
            return GetWrappedNativeOfJSObject(cx, outer, funobj, pobj2,
                                              pTearOff);
    }

    return nsnull;
}

JSBool
XPCWrappedNative::ExtendSet(XPCCallContext& ccx, XPCNativeInterface* aInterface)
{
    // This is only called while locked (during XPCWrappedNative::FindTearOff).

    if(!mSet->HasInterface(aInterface))
    {
        AutoMarkingNativeSetPtr newSet(ccx);
        newSet = XPCNativeSet::GetNewOrUsed(ccx, mSet, aInterface,
                                            mSet->GetInterfaceCount());
        if(!newSet)
            return JS_FALSE;

        mSet = newSet;

        DEBUG_ReportShadowedMembers(newSet, this, GetProto());
    }
    return JS_TRUE;
}

XPCWrappedNativeTearOff*
XPCWrappedNative::LocateTearOff(XPCCallContext& ccx,
                              XPCNativeInterface* aInterface)
{
    XPCAutoLock al(GetLock()); // hold the lock throughout

    for(
        XPCWrappedNativeTearOffChunk* chunk = &mFirstChunk;
        chunk != nsnull;
        chunk = chunk->mNextChunk)
    {
        XPCWrappedNativeTearOff* tearOff = chunk->mTearOffs;
        XPCWrappedNativeTearOff* const end = tearOff + 
            XPC_WRAPPED_NATIVE_TEAROFFS_PER_CHUNK;
        for(
            tearOff = chunk->mTearOffs;
            tearOff < end; 
            tearOff++)
        {
            if(tearOff->GetInterface() == aInterface)
            {
                return tearOff;
            }
        }
    }
    return nsnull;
}

XPCWrappedNativeTearOff*
XPCWrappedNative::FindTearOff(XPCCallContext& ccx,
                              XPCNativeInterface* aInterface,
                              JSBool needJSObject /* = JS_FALSE */,
                              nsresult* pError /* = nsnull */)
{
    XPCAutoLock al(GetLock()); // hold the lock throughout

    nsresult rv = NS_OK;
    XPCWrappedNativeTearOff* to;
    XPCWrappedNativeTearOff* firstAvailable = nsnull;

    XPCWrappedNativeTearOffChunk* lastChunk;
    XPCWrappedNativeTearOffChunk* chunk;
    for(lastChunk = chunk = &mFirstChunk;
        chunk;
        lastChunk = chunk, chunk = chunk->mNextChunk)
    {
        to = chunk->mTearOffs;
        XPCWrappedNativeTearOff* const end = chunk->mTearOffs + 
            XPC_WRAPPED_NATIVE_TEAROFFS_PER_CHUNK;
        for(
            to = chunk->mTearOffs;
            to < end; 
            to++)
        {
            if(to->GetInterface() == aInterface)
            {
                if(needJSObject && !to->GetJSObject())
                {
                    AutoMarkingWrappedNativeTearOffPtr tearoff(ccx, to);
                    rv = InitTearOffJSObject(ccx, to);
                    // During shutdown, we don't sweep tearoffs.  So make sure
                    // to unmark manually in case the auto-marker marked us.
                    // We shouldn't ever be getting here _during_ our
                    // Mark/Sweep cycle, so this should be safe.
                    to->Unmark();
                    if(NS_FAILED(rv))
                        to = nsnull;
                }
                goto return_result;
            }
            if(!firstAvailable && to->IsAvailable())
                firstAvailable = to;
        }
    }

    to = firstAvailable;

    if(!to)
    {
        XPCWrappedNativeTearOffChunk* newChunk =
            new XPCWrappedNativeTearOffChunk();
        if(!newChunk)
        {
            rv = NS_ERROR_OUT_OF_MEMORY;
            goto return_result;
        }
        lastChunk->mNextChunk = newChunk;
        to = newChunk->mTearOffs;
    }

    {
        // Scope keeps |tearoff| from leaking across the return_result: label
        AutoMarkingWrappedNativeTearOffPtr tearoff(ccx, to);
        rv = InitTearOff(ccx, to, aInterface, needJSObject);
        // During shutdown, we don't sweep tearoffs.  So make sure to unmark
        // manually in case the auto-marker marked us.  We shouldn't ever be
        // getting here _during_ our Mark/Sweep cycle, so this should be safe.
        to->Unmark();
        if(NS_FAILED(rv))
            to = nsnull;
    }

return_result:

    if(pError)
        *pError = rv;
    return to;
}

nsresult
XPCWrappedNative::InitTearOff(XPCCallContext& ccx,
                              XPCWrappedNativeTearOff* aTearOff,
                              XPCNativeInterface* aInterface,
                              JSBool needJSObject)
{
    // This is only called while locked (during XPCWrappedNative::FindTearOff).

    // Determine if the object really does this interface...

    const nsIID* iid = aInterface->GetIID();
    nsISupports* identity = GetIdentityObject();
    nsISupports* obj;

    // If the scriptable helper forbids us from reflecting additional
    // interfaces, then don't even try the QI, just fail.
    if(mScriptableInfo &&
       mScriptableInfo->GetFlags().ClassInfoInterfacesOnly() &&
       !mSet->HasInterface(aInterface) &&
       !mSet->HasInterfaceWithAncestor(aInterface))
    {
        return NS_ERROR_NO_INTERFACE;
    }

    // We are about to call out to unlock and other code.
    // So protect our intended tearoff.

    aTearOff->SetReserved();

    {   // scoped *un*lock
        XPCAutoUnlock unlock(GetLock());

        if(NS_FAILED(identity->QueryInterface(*iid, (void**)&obj)) || !obj)
        {
            aTearOff->SetInterface(nsnull);
            return NS_ERROR_NO_INTERFACE;
        }

        // Guard against trying to build a tearoff for a shared nsIClassInfo.
        if(iid->Equals(NS_GET_IID(nsIClassInfo)))
        {
            nsCOMPtr<nsISupports> alternate_identity(do_QueryInterface(obj));
            if(alternate_identity.get() != identity)
            {
                NS_RELEASE(obj);
                aTearOff->SetInterface(nsnull);
                return NS_ERROR_NO_INTERFACE;
            }
        }

        // Guard against trying to build a tearoff for an interface that is
        // aggregated and is implemented as a nsIXPConnectWrappedJS using this
        // self-same JSObject. The XBL system does this. If we mutate the set
        // of this wrapper then we will shadow the method that XBL has added to
        // the JSObject that it has inserted in the JS proto chain between our
        // JSObject and our XPCWrappedNativeProto's JSObject. If we let this
        // set mutation happen then the interface's methods will be added to 
        // our JSObject, but calls on those methods will get routed up to
        // native code and into the wrappedJS - which will do a method lookup
        // on *our* JSObject and find the same method and make another call
        // into an infinite loop.
        // see: http://bugzilla.mozilla.org/show_bug.cgi?id=96725

        // The code in this block also does a check for the double wrapped
        // nsIPropertyBag case.

        nsCOMPtr<nsIXPConnectWrappedJS> wrappedJS(do_QueryInterface(obj));
        if(wrappedJS)
        {
            JSObject* jso = nsnull;
            if(NS_SUCCEEDED(wrappedJS->GetJSObject(&jso)) &&
               jso == GetFlatJSObject())
            {
                // The implementing JSObject is the same as ours! Just say OK
                // without actually extending the set.
                //
                // XXX It is a little cheesy to have FindTearOff return an
                // 'empty' tearoff. But this is the centralized place to do the
                // QI activities on the underlying object. *And* most caller to
                // FindTearOff only look for a non-null result and ignore the
                // actual tearoff returned. The only callers that do use the
                // returned tearoff make sure to check for either a non-null 
                // JSObject or a matching Interface before proceeding.
                // I think we can get away with this bit of ugliness.
                
#ifdef DEBUG_xpc_hacker
                {
                    // I want to make sure this only happens in xbl-like cases.
                    // So, some debug code to verify that there is at least
                    // *some* object between our JSObject and its inital proto.
                    // XXX This is a pretty funky test. Someone might hack it
                    // a bit if false positives start showing up. Note that 
                    // this is only going to run for the few people in the
                    // DEBUG_xpc_hacker list.
                    if(HasProto())
                    {
                        JSObject* proto  = nsnull;
                        JSObject* our_proto = GetProto()->GetJSProtoObject();

                        proto = JS_GetPrototype(ccx, jso);

                        NS_WARN_IF_FALSE(proto && proto != our_proto,
                            "!!! xpconnect/xbl check - wrapper has no special proto");

                        PRBool found_our_proto = PR_FALSE;
                        while (proto && !found_our_proto) {
                            proto = JS_GetPrototype(ccx, proto);

                            found_our_proto = proto == our_proto;
                        }

                        NS_WARN_IF_FALSE(found_our_proto,
                            "!!! xpconnect/xbl check - wrapper has extra proto");
                    }
                    else
                    {
                        NS_WARNING("!!! xpconnect/xbl check - wrapper has no proto");
                    }
                }
#endif
                NS_RELEASE(obj);
                aTearOff->SetInterface(nsnull);
                return NS_OK;
            }
            
            // Decide whether or not to expose nsIPropertyBag to calling
            // JS code in the double wrapped case.
            //
            // Our rule here is that when JSObjects are double wrapped and
            // exposed to other JSObjects then the nsIPropertyBag interface
            // is only exposed on an 'opt-in' basis; i.e. if the underlying
            // JSObject wants other JSObjects to be able to see this interface
            // then it must implement QueryInterface and not throw an exception
            // when asked for nsIPropertyBag. It need not actually *implement*
            // nsIPropertyBag - xpconnect will do that work.

            nsXPCWrappedJSClass* clazz;
            if(iid->Equals(NS_GET_IID(nsIPropertyBag)) && jso &&
               NS_SUCCEEDED(nsXPCWrappedJSClass::GetNewOrUsed(ccx,*iid,&clazz))&&
               clazz)
            {
                JSObject* answer =
                    clazz->CallQueryInterfaceOnJSObject(ccx, jso, *iid);
                NS_RELEASE(clazz);
                if(!answer)
                {
                    NS_RELEASE(obj);
                    aTearOff->SetInterface(nsnull);
                    return NS_ERROR_NO_INTERFACE;
                }
            }
        }

        nsIXPCSecurityManager* sm;
           sm = ccx.GetXPCContext()->GetAppropriateSecurityManager(
                                nsIXPCSecurityManager::HOOK_CREATE_WRAPPER);
        if(sm && NS_FAILED(sm->
                    CanCreateWrapper(ccx, *iid, identity,
                                     GetClassInfo(), GetSecurityInfoAddr())))
        {
            // the security manager vetoed. It should have set an exception.
            NS_RELEASE(obj);
            aTearOff->SetInterface(nsnull);
            return NS_ERROR_XPC_SECURITY_MANAGER_VETO;
        }
    }
    // We are relocked from here on...

    // If this is not already in our set we need to extend our set.
    // Note: we do not cache the result of the previous call to HasInterface()
    // because we unlocked and called out in the interim and the result of the
    // previous call might not be correct anymore.

    if(!mSet->HasInterface(aInterface) && !ExtendSet(ccx, aInterface))
    {
        NS_RELEASE(obj);
        aTearOff->SetInterface(nsnull);
        return NS_ERROR_NO_INTERFACE;
    }

    aTearOff->SetInterface(aInterface);
    aTearOff->SetNative(obj);
#ifdef XPC_IDISPATCH_SUPPORT
    // Are we building a tearoff for IDispatch?
    if(iid->Equals(NSID_IDISPATCH))
    {
        aTearOff->SetIDispatch(ccx);
    }  
#endif
    if(needJSObject && !InitTearOffJSObject(ccx, aTearOff))
        return NS_ERROR_OUT_OF_MEMORY;

    return NS_OK;
}

JSBool
XPCWrappedNative::InitTearOffJSObject(XPCCallContext& ccx,
                                      XPCWrappedNativeTearOff* to)
{
    // This is only called while locked (during XPCWrappedNative::FindTearOff).

    JSObject* obj = JS_NewObject(ccx, &XPC_WN_Tearoff_JSClass,
                                 GetScope()->GetPrototypeJSObject(),
                                 mFlatJSObject);

    if(!obj || !JS_SetPrivate(ccx, obj, to))
        return JS_FALSE;

    // Propagate the system flag from parent to child.
    if(JS_IsSystemObject(ccx, mFlatJSObject))
        JS_FlagSystemObject(ccx, obj);

    to->SetJSObject(obj);
    return JS_TRUE;
}

/***************************************************************************/

static JSBool Throw(uintN errNum, XPCCallContext& ccx)
{
    XPCThrower::Throw(errNum, ccx);
    return JS_FALSE;
}

enum SizeMode {GET_SIZE, GET_LENGTH};

/***************************************************************************/

static JSBool
GetArraySizeFromParam(XPCCallContext& ccx,
                      nsIInterfaceInfo* ifaceInfo,
                      const nsXPTMethodInfo* methodInfo,
                      const nsXPTParamInfo& paramInfo,
                      uint16 vtblIndex,
                      uint8 paramIndex,
                      SizeMode mode,
                      nsXPTCVariant* dispatchParams,
                      JSUint32* result)
{
    uint8 argnum;
    nsresult rv;

    // XXX fixup the various exceptions that are thrown

    if(mode == GET_SIZE)
        rv = ifaceInfo->GetSizeIsArgNumberForParam(vtblIndex, &paramInfo, 0, &argnum);
    else
        rv = ifaceInfo->GetLengthIsArgNumberForParam(vtblIndex, &paramInfo, 0, &argnum);
    if(NS_FAILED(rv))
        return Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, ccx);

    const nsXPTParamInfo& arg_param = methodInfo->GetParam(argnum);
    const nsXPTType& arg_type = arg_param.GetType();

    // The xpidl compiler ensures this. We reaffirm it for safety.
    if(arg_type.IsPointer() || arg_type.TagPart() != nsXPTType::T_U32)
        return Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, ccx);

    *result = dispatchParams[argnum].val.u32;

    return JS_TRUE;
}


static JSBool
GetInterfaceTypeFromParam(XPCCallContext& ccx,
                          nsIInterfaceInfo* ifaceInfo,
                          const nsXPTMethodInfo* methodInfo,
                          const nsXPTParamInfo& paramInfo,
                          uint16 vtblIndex,
                          uint8 paramIndex,
                          const nsXPTType& datum_type,
                          nsXPTCVariant* dispatchParams,
                          nsID* result)
{
    uint8 argnum;
    nsresult rv;
    uint8 type_tag = datum_type.TagPart();

    // XXX fixup the various exceptions that are thrown

    if(type_tag == nsXPTType::T_INTERFACE)
    {
        rv = ifaceInfo->GetIIDForParamNoAlloc(vtblIndex, &paramInfo, result);
        if(NS_FAILED(rv))
            return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, paramIndex, ccx);
    }
    else if(type_tag == nsXPTType::T_INTERFACE_IS)
    {
        rv = ifaceInfo->GetInterfaceIsArgNumberForParam(vtblIndex, &paramInfo, &argnum);
        if(NS_FAILED(rv))
            return Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, ccx);

        const nsXPTParamInfo& arg_param = methodInfo->GetParam(argnum);
        const nsXPTType& arg_type = arg_param.GetType();
        
        // The xpidl compiler ensures this. We reaffirm it for safety.
        if(!arg_type.IsPointer() || arg_type.TagPart() != nsXPTType::T_IID)
            return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, paramIndex, ccx);

        nsID* p = (nsID*) dispatchParams[argnum].val.p;
        if(!p)
            return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, paramIndex, ccx);
        *result = *p;
    }
    return JS_TRUE;
}

/***************************************************************************/

// static
JSBool
XPCWrappedNative::CallMethod(XPCCallContext& ccx,
                             CallMode mode /*= CALL_METHOD */)
{
    nsresult rv = ccx.CanCallNow();
    if(NS_FAILED(rv))
    {
        // If the security manager is complaining then this is not really an
        // internal error in xpconnect. So, no reason to botch the assertion.
        NS_ASSERTION(rv == NS_ERROR_XPC_SECURITY_MANAGER_VETO, 
                     "hmm? CanCallNow failed in XPCWrappedNative::CallMethod. "
                     "We are finding out about this late!");
        return Throw(rv, ccx);
    }

    DEBUG_TrackWrapperCall(ccx.GetWrapper(), mode);

    // From here on ALL exits are through 'goto done;'

#define PARAM_BUFFER_COUNT     8

    nsXPTCVariant paramBuffer[PARAM_BUFFER_COUNT];

    // Number of nsAutoStrings to construct on the stack for use with method
    // calls that use 'out' AStrings (aka [domstring]). These can save us from 
    // a new/delete of an nsString. But the cost is that the ctor/dtor code 
    // is run for each nsAutoString in the array for each call - whether or not 
    // a specific call actually uses *any* AStrings. Also, we have these
    // large-ish nsAutoString objects using up stack space.
    //
    // Set this to zero to disable use of these auto strings.
#define PARAM_AUTOSTRING_COUNT     1

#if PARAM_AUTOSTRING_COUNT
    nsVoidableString autoStrings[PARAM_AUTOSTRING_COUNT];
    int autoStringIndex = 0;
#endif

    JSBool retval = JS_FALSE;

    nsXPTCVariant* dispatchParams = nsnull;
    uint8 i;
    const nsXPTMethodInfo* methodInfo;
    uint8 requiredArgs;
    uint8 paramCount;
    jsval src;
    nsresult invokeResult;
    nsID param_iid;
    uintN err;
    nsIXPCSecurityManager* sm;
    JSBool foundDependentParam;

    XPCJSRuntime* rt = ccx.GetRuntime();
    XPCContext* xpcc = ccx.GetXPCContext();
    nsISupports* callee = ccx.GetTearOff()->GetNative();
    XPCPerThreadData* tls = ccx.GetThreadData();
    uint16 vtblIndex = ccx.GetMethodIndex();
    nsIInterfaceInfo* ifaceInfo = ccx.GetInterface()->GetInterfaceInfo();
    jsval name = ccx.GetMember()->GetName();
    jsval* argv = ccx.GetArgv();

#ifdef DEBUG_stats_jband
    PRIntervalTime startTime = PR_IntervalNow();
    PRIntervalTime endTime = 0;
    static int totalTime = 0;
    static int count = 0;
    static const int interval = 10;
    if(0 == (++count % interval))
        printf(">>>>>>>> %d calls on XPCWrappedNatives made.  (%d)\n", count, PR_IntervalToMilliseconds(totalTime));
#endif

    ccx.SetRetVal(JSVAL_VOID);

    tls->SetException(nsnull);
    xpcc->SetLastResult(NS_ERROR_UNEXPECTED);

    // set up the method index and do the security check if needed

    PRUint32 secFlag;
    PRUint32 secAction;

    switch(mode)
    {
        case CALL_METHOD:
            secFlag   = nsIXPCSecurityManager::HOOK_CALL_METHOD;
            secAction = nsIXPCSecurityManager::ACCESS_CALL_METHOD;
            break;
        case CALL_GETTER:
            secFlag   = nsIXPCSecurityManager::HOOK_GET_PROPERTY;
            secAction = nsIXPCSecurityManager::ACCESS_GET_PROPERTY;
            break;
        case CALL_SETTER:
            secFlag   = nsIXPCSecurityManager::HOOK_SET_PROPERTY;
            secAction = nsIXPCSecurityManager::ACCESS_SET_PROPERTY;
            break;
        default:
            NS_ASSERTION(0,"bad value");
            goto done;
    }

    sm = xpcc->GetAppropriateSecurityManager(secFlag);
    if(sm && NS_FAILED(sm->CanAccess(secAction, &ccx, ccx,
                                     ccx.GetFlattenedJSObject(),
                                     ccx.GetWrapper()->GetIdentityObject(),
                                     ccx.GetWrapper()->GetClassInfo(), name,
                                     ccx.GetWrapper()->GetSecurityInfoAddr())))
    {
        // the security manager vetoed. It should have set an exception.
        goto done;
    }

    if(NS_FAILED(ifaceInfo->GetMethodInfo(vtblIndex, &methodInfo)))
    {
        Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, ccx);
        goto done;
    }

    // XXX ASSUMES that retval is last arg. The xpidl compiler ensures this.
    paramCount = methodInfo->GetParamCount();
    requiredArgs = paramCount;
    if(paramCount && methodInfo->GetParam(paramCount-1).IsRetval())
        requiredArgs--;
    if(ccx.GetArgc() < requiredArgs)
    {
        Throw(NS_ERROR_XPC_NOT_ENOUGH_ARGS, ccx);
        goto done;
    }

    // setup variant array pointer
    if(paramCount > PARAM_BUFFER_COUNT)
    {
        if(!(dispatchParams = new nsXPTCVariant[paramCount]))
        {
            JS_ReportOutOfMemory(ccx);
            goto done;
        }
    }
    else
        dispatchParams = paramBuffer;

    // iterate through the params to clear flags (for safe cleanup later)
    for(i = 0; i < paramCount; i++)
    {
        nsXPTCVariant* dp = &dispatchParams[i];
        dp->ClearFlags();
        dp->val.p = nsnull;
    }

    // Iterate through the params doing conversions of independent params only.
    // When we later convert the dependent params (if any) we will know that
    // the params upon which they depend will have already been converted -
    // regardless of ordering.
    foundDependentParam = JS_FALSE;
    for(i = 0; i < paramCount; i++)
    {
        JSBool useAllocator = JS_FALSE;
        const nsXPTParamInfo& paramInfo = methodInfo->GetParam(i);
        const nsXPTType& type = paramInfo.GetType();
        uint8 type_tag = type.TagPart();

        if(type.IsDependent())
        {
            foundDependentParam = JS_TRUE;
            continue;
        }

        nsXPTCVariant* dp = &dispatchParams[i];
        dp->type = type;

        if(type_tag == nsXPTType::T_INTERFACE)
        {
            dp->SetValIsInterface();
        }

        // set 'src' to be the object from which we get the value and
        // prepare for out param

        if(paramInfo.IsOut())
        {
            dp->SetPtrIsData();
            dp->ptr = &dp->val;

            if(!paramInfo.IsRetval() &&
               (JSVAL_IS_PRIMITIVE(argv[i]) ||
                !OBJ_GET_PROPERTY(ccx, JSVAL_TO_OBJECT(argv[i]),
                                  rt->GetStringID(XPCJSRuntime::IDX_VALUE),
                                  &src)))
            {
                ThrowBadParam(NS_ERROR_XPC_NEED_OUT_OBJECT, i, ccx);
                goto done;
            }

            if(type.IsPointer() &&
               type_tag != nsXPTType::T_INTERFACE &&
               !paramInfo.IsShared())
            {
                useAllocator = JS_TRUE;
                dp->SetValIsAllocated();
            }

            if(!paramInfo.IsIn())
                continue;
        }
        else
        {
            if(type.IsPointer())
            {
                switch(type_tag)
                {
                case nsXPTType::T_IID:
                    dp->SetValIsAllocated();
                    useAllocator = JS_TRUE;
                    break;

                case nsXPTType::T_ASTRING:
                    // Fall through to the T_DOMSTRING case

                case nsXPTType::T_DOMSTRING:
                    if(paramInfo.IsDipper())
                    {
                        // Is an 'out' DOMString. Make a new nsAString
                        // now and then continue in order to skip the call to
                        // JSData2Native

                        // If autoStrings array support is enabld, then use
                        // one of them if they are not already used up.
#if PARAM_AUTOSTRING_COUNT
                        if(autoStringIndex < PARAM_AUTOSTRING_COUNT)
                        {
                            // Don't call SetValIsDOMString because we don't 
                            // want to delete this pointer.
                            dp->val.p = &autoStrings[autoStringIndex++];
                            continue;
                        }
#endif
                        dp->SetValIsDOMString();
                        if(!(dp->val.p = new nsVoidableString()))
                        {
                            JS_ReportOutOfMemory(ccx);
                            goto done;
                        }
                        continue;
                    }
                    // else...

                    // Is an 'in' DOMString. Set 'useAllocator' to indicate
                    // that JSData2Native should allocate a new
                    // nsAString.
                    dp->SetValIsDOMString();
                    useAllocator = JS_TRUE;
                    break;

                case nsXPTType::T_UTF8STRING:                    
                    // Fall through to the C string case for now...                    
                case nsXPTType::T_CSTRING:                    
                    dp->SetValIsCString();
                    if(paramInfo.IsDipper())
                    {
                        // Is an 'out' CString.
                        if(!(dp->val.p = new nsCString()))
                        {
                            JS_ReportOutOfMemory(ccx);
                            goto done;
                        }
                        continue;
                    }
                    // else ...
                    // Is an 'in' CString.
                    useAllocator = JS_TRUE;
                    break;
                }
            }

            // Do this *after* the above because in the case where we have a
            // "T_DOMSTRING && IsDipper()" then argv might be null since this
            // is really an 'out' param masquerading as an 'in' param.
            src = argv[i];
        }

        if(type_tag == nsXPTType::T_INTERFACE &&
           NS_FAILED(ifaceInfo->GetIIDForParamNoAlloc(vtblIndex, &paramInfo,
                                               &param_iid)))
        {
            ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, i, ccx);
            goto done;
        }

        if(!XPCConvert::JSData2Native(ccx, &dp->val, src, type,
                                      useAllocator, &param_iid, &err))
        {
            ThrowBadParam(err, i, ccx);
            goto done;
        }
    }

    // if any params were dependent, then we must iterate again to convert them.
    if(foundDependentParam)
    {
        for(i = 0; i < paramCount; i++)
        {
            const nsXPTParamInfo& paramInfo = methodInfo->GetParam(i);
            const nsXPTType& type = paramInfo.GetType();

            if(!type.IsDependent())
                continue;

            nsXPTType datum_type;
            JSUint32 array_count;
            JSUint32 array_capacity;
            JSBool useAllocator = JS_FALSE;
            PRBool isArray = type.IsArray();

            PRBool isSizedString = isArray ?
                    JS_FALSE :
                    type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
                    type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;

            nsXPTCVariant* dp = &dispatchParams[i];
            dp->type = type;

            if(isArray)
            {
                dp->SetValIsArray();

                if(NS_FAILED(ifaceInfo->GetTypeForParam(vtblIndex, &paramInfo, 1,
                                                    &datum_type)))
                {
                    Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, ccx);
                    goto done;
                }
            }
            else
                datum_type = type;

            if(datum_type.IsInterfacePointer())
            {
                dp->SetValIsInterface();
            }

            // set 'src' to be the object from which we get the value and
            // prepare for out param

            if(paramInfo.IsOut())
            {
                dp->SetPtrIsData();
                dp->ptr = &dp->val;

                if(!paramInfo.IsRetval() &&
                   (JSVAL_IS_PRIMITIVE(argv[i]) ||
                    !OBJ_GET_PROPERTY(ccx, JSVAL_TO_OBJECT(argv[i]),
                        rt->GetStringID(XPCJSRuntime::IDX_VALUE), &src)))
                {
                    ThrowBadParam(NS_ERROR_XPC_NEED_OUT_OBJECT, i, ccx);
                    goto done;
                }

                if(datum_type.IsPointer() &&
                   !datum_type.IsInterfacePointer() &&
                   (isArray || !paramInfo.IsShared()))
                {
                    useAllocator = JS_TRUE;
                    dp->SetValIsAllocated();
                }

                if(!paramInfo.IsIn())
                    continue;
            }
            else
            {
                src = argv[i];

                if(datum_type.IsPointer() &&
                   datum_type.TagPart() == nsXPTType::T_IID)
                {
                    useAllocator = JS_TRUE;
                    dp->SetValIsAllocated();
                }
            }

            if(datum_type.IsInterfacePointer() &&
               !GetInterfaceTypeFromParam(ccx, ifaceInfo, methodInfo, paramInfo,
                                          vtblIndex, i, datum_type,
                                          dispatchParams, &param_iid))
                goto done;

            if(isArray || isSizedString)
            {
                if(!GetArraySizeFromParam(ccx, ifaceInfo, methodInfo, paramInfo,
                                          vtblIndex, i, GET_SIZE,
                                          dispatchParams, &array_capacity)||
                   !GetArraySizeFromParam(ccx, ifaceInfo, methodInfo, paramInfo,
                                          vtblIndex, i, GET_LENGTH,
                                          dispatchParams, &array_count))
                    goto done;

                if(isArray)
                {
                    if(array_count &&
                       !XPCConvert::JSArray2Native(ccx, (void**)&dp->val, src,
                                                   array_count, array_capacity,
                                                   datum_type,
                                                   useAllocator,
                                                   &param_iid, &err))
                    {
                        // XXX need exception scheme for arrays to indicate bad element
                        ThrowBadParam(err, i, ccx);
                        goto done;
                    }
                }
                else // if(isSizedString)
                {
                    if(!XPCConvert::JSStringWithSize2Native(ccx,
                                                   (void*)&dp->val,
                                                   src,
                                                   array_count, array_capacity,
                                                   datum_type, useAllocator,
                                                   &err))
                    {
                        ThrowBadParam(err, i, ccx);
                        goto done;
                    }
                }
            }
            else
            {
                if(!XPCConvert::JSData2Native(ccx, &dp->val, src, type,
                                              useAllocator, &param_iid,
                                              &err))
                {
                    ThrowBadParam(err, i, ccx);
                    goto done;
                }
            }
        }
    }


    {
        // avoid deadlock in case the native method blocks somehow
        AutoJSSuspendRequest req(ccx);  // scoped suspend of request

        // do the invoke
        invokeResult = XPTC_InvokeByIndex(callee, vtblIndex,
                                          paramCount, dispatchParams);
        // resume non-blocking JS operations now
    }


    xpcc->SetLastResult(invokeResult);

    if(NS_FAILED(invokeResult))
    {
        ThrowBadResult(invokeResult, ccx);
        goto done;
    }
    else if(ccx.GetExceptionWasThrown())
    {
        // the native callee claims to have already set a JSException
        goto done;
    }

    // now we iterate through the native params to gather and convert results
    for(i = 0; i < paramCount; i++)
    {
        const nsXPTParamInfo& paramInfo = methodInfo->GetParam(i);
        if(!paramInfo.IsOut() && !paramInfo.IsDipper())
            continue;

        const nsXPTType& type = paramInfo.GetType();
        nsXPTCVariant* dp = &dispatchParams[i];
        jsval v = JSVAL_NULL;
        AUTO_MARK_JSVAL(ccx, &v);
        JSUint32 array_count;
        nsXPTType datum_type;
        PRBool isArray = type.IsArray();
        PRBool isSizedString = isArray ?
                JS_FALSE :
                type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
                type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;

        if(isArray)
        {
            if(NS_FAILED(ifaceInfo->GetTypeForParam(vtblIndex, &paramInfo, 1,
                                                    &datum_type)))
            {
                Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, ccx);
                goto done;
            }
        }
        else
            datum_type = type;

        if(isArray || isSizedString)
        {
            if(!GetArraySizeFromParam(ccx, ifaceInfo, methodInfo, paramInfo,
                                      vtblIndex, i, GET_LENGTH, dispatchParams,
                                      &array_count))
                goto done;
        }

        if(datum_type.IsInterfacePointer() &&
           !GetInterfaceTypeFromParam(ccx, ifaceInfo, methodInfo, paramInfo,
                                      vtblIndex, i, datum_type, dispatchParams,
                                      &param_iid))
            goto done;

        if(isArray)
        {
            if(!XPCConvert::NativeArray2JS(ccx, &v, (const void**)&dp->val,
                                           datum_type, &param_iid,
                                           array_count, ccx.GetCurrentJSObject(),
                                           &err))
            {
                // XXX need exception scheme for arrays to indicate bad element
                ThrowBadParam(err, i, ccx);
                goto done;
            }
        }
        else if(isSizedString)
        {
            if(!XPCConvert::NativeStringWithSize2JS(ccx, &v,
                                           (const void*)&dp->val,
                                           datum_type,
                                           array_count, &err))
            {
                ThrowBadParam(err, i, ccx);
                goto done;
            }
        }
        else
        {
            if(!XPCConvert::NativeData2JS(ccx, &v, &dp->val, datum_type,
                                          &param_iid,
                                          ccx.GetCurrentJSObject(), &err))
            {
                ThrowBadParam(err, i, ccx);
                goto done;
            }
        }

        if(paramInfo.IsRetval())
        {
            if(!ccx.GetReturnValueWasSet())
                ccx.SetRetVal(v);
        }
        else
        {
            // we actually assured this before doing the invoke
            NS_ASSERTION(JSVAL_IS_OBJECT(argv[i]), "out var is not object");
            if(!OBJ_SET_PROPERTY(ccx, JSVAL_TO_OBJECT(argv[i]),
                        rt->GetStringID(XPCJSRuntime::IDX_VALUE), &v))
            {
                ThrowBadParam(NS_ERROR_XPC_CANT_SET_OUT_VAL, i, ccx);
                goto done;
            }
        }
    }

    retval = JS_TRUE;
done:
    // iterate through the params (again!) and clean up
    // any alloc'd stuff and release wrappers of params
    if(dispatchParams)
    {
        for(i = 0; i < paramCount; i++)
        {
            nsXPTCVariant* dp = &dispatchParams[i];
            void* p = dp->val.p;
            if(!p)
                continue;

            if(dp->IsValArray())
            {
                // going to have to cleanup the array and perhaps its contents
                if(dp->IsValAllocated() || dp->IsValInterface())
                {
                    // we need to figure out how many elements are present.
                    JSUint32 array_count;

                    const nsXPTParamInfo& paramInfo = methodInfo->GetParam(i);
                    if(!GetArraySizeFromParam(ccx, ifaceInfo, methodInfo,
                                              paramInfo, vtblIndex,
                                              i, GET_LENGTH, dispatchParams,
                                              &array_count))
                    {
                        NS_ASSERTION(0,"failed to get array length, we'll leak here");
                        continue;
                    }
                    if(dp->IsValAllocated())
                    {
                        void** a = (void**)p;
                        for(JSUint32 k = 0; k < array_count; k++)
                        {
                            void* o = a[k];
                            if(o) nsMemory::Free(o);
                        }
                    }
                    else // if(dp->IsValInterface())
                    {
                        nsISupports** a = (nsISupports**)p;
                        for(JSUint32 k = 0; k < array_count; k++)
                        {
                            nsISupports* o = a[k];
                            NS_IF_RELEASE(o);
                        }
                    }
                }
                // always free the array itself
                nsMemory::Free(p);
            }
            else if(dp->IsValAllocated())
                nsMemory::Free(p);
            else if(dp->IsValInterface())
                ((nsISupports*)p)->Release();
            else if(dp->IsValDOMString())
                delete (nsAString*)p;
            else if(dp->IsValUTF8String())
                delete (nsCString*) p;
            else if(dp->IsValCString())
                delete (nsCString*) p;
        }   
    }

    if(dispatchParams && dispatchParams != paramBuffer)
        delete [] dispatchParams;

#ifdef off_DEBUG_stats_jband
    endTime = PR_IntervalNow();

    printf("%s::%s %d ( js->c ) \n",
           ccx.GetInterface()->GetNameString(),
           ccx.GetInterface()->GetMemberName(ccx, ccx.GetMember()),
           PR_IntervalToMilliseconds(endTime-startTime));

    totalTime += (endTime-startTime);
#endif

    return retval;
}

/***************************************************************************/
// interface methods

/* readonly attribute JSObjectPtr JSObject; */
NS_IMETHODIMP XPCWrappedNative::GetJSObject(JSObject * *aJSObject)
{
    *aJSObject = mFlatJSObject;
    return NS_OK;
}

/* readonly attribute nsISupports Native; */
NS_IMETHODIMP XPCWrappedNative::GetNative(nsISupports * *aNative)
{
    // No need to QI here, we already have the correct nsISupports
    // vtable.
    *aNative = mIdentity;
    NS_ADDREF(*aNative);
    return NS_OK;
}

/* readonly attribute JSObjectPtr JSObjectPrototype; */
NS_IMETHODIMP XPCWrappedNative::GetJSObjectPrototype(JSObject * *aJSObjectPrototype)
{
    *aJSObjectPrototype = HasProto() ?
                GetProto()->GetJSProtoObject() : GetFlatJSObject();
    return NS_OK;
}

/* readonly attribute nsIXPConnect XPConnect; */
NS_IMETHODIMP XPCWrappedNative::GetXPConnect(nsIXPConnect * *aXPConnect)
{
    if(IsValid())
    {
        nsIXPConnect* temp = GetRuntime()->GetXPConnect();
        NS_IF_ADDREF(temp);
        *aXPConnect = temp;
    }
    else
        *aXPConnect = nsnull;
    return NS_OK;
}

/* XPCNativeInterface FindInterfaceWithMember (in JSVal name); */
NS_IMETHODIMP XPCWrappedNative::FindInterfaceWithMember(jsval name, nsIInterfaceInfo * *_retval)
{
    XPCNativeInterface* iface;
    XPCNativeMember*  member;

    if(GetSet()->FindMember(name, &member, &iface) && iface)
    {
        nsIInterfaceInfo* temp = iface->GetInterfaceInfo();
        NS_IF_ADDREF(temp);
        *_retval = temp;
    }
    else
        *_retval = nsnull;
    return NS_OK;
}

/* XPCNativeInterface FindInterfaceWithName (in JSVal name); */
NS_IMETHODIMP XPCWrappedNative::FindInterfaceWithName(jsval name, nsIInterfaceInfo * *_retval)
{
    XPCNativeInterface* iface = GetSet()->FindNamedInterface(name);
    if(iface)
    {
        nsIInterfaceInfo* temp = iface->GetInterfaceInfo();
        NS_IF_ADDREF(temp);
        *_retval = temp;
    }
    else
        *_retval = nsnull;
    return NS_OK;
}

inline nsresult UnexpectedFailure(nsresult rv)
{
    NS_ERROR("This is not supposed to fail!");
    return rv;
}

/* void refreshPrototype (); */
NS_IMETHODIMP XPCWrappedNative::RefreshPrototype()
{
    XPCCallContext ccx(NATIVE_CALLER);
    if(!ccx.IsValid())
        return UnexpectedFailure(NS_ERROR_FAILURE);

    if(!HasProto())
        return NS_OK;

    if(!GetFlatJSObject())
        return UnexpectedFailure(NS_ERROR_FAILURE);

    AutoMarkingWrappedNativeProtoPtr oldProto(ccx);
    AutoMarkingWrappedNativeProtoPtr newProto(ccx);
    
    oldProto = GetProto();
    XPCNativeScriptableCreateInfo ci(*oldProto->GetScriptableInfo());
    newProto = XPCWrappedNativeProto::GetNewOrUsed(ccx, oldProto->GetScope(),
                                                   oldProto->GetClassInfo(),
                                                   &ci,
                                                   !oldProto->IsShared());
    if(!newProto)
        return UnexpectedFailure(NS_ERROR_FAILURE);

    // If nothing needs to change then we're done.

    if(newProto.get() == oldProto.get())
        return NS_OK;

    if(!JS_SetPrototype(ccx, GetFlatJSObject(), newProto->GetJSProtoObject()))
        return UnexpectedFailure(NS_ERROR_FAILURE);

    mMaybeProto = newProto;

    if(mScriptableInfo == oldProto->GetScriptableInfo())
        mScriptableInfo = newProto->GetScriptableInfo();

    return NS_OK;
}

NS_IMETHODIMP XPCWrappedNative::GetSecurityInfoAddress(void*** securityInfoAddrPtr)
{
    NS_ENSURE_ARG_POINTER(securityInfoAddrPtr);
    *securityInfoAddrPtr = GetSecurityInfoAddr();
    return NS_OK;
}

/* void debugDump (in short depth); */
NS_IMETHODIMP XPCWrappedNative::DebugDump(PRInt16 depth)
{
#ifdef DEBUG
    depth-- ;
    XPC_LOG_ALWAYS(("XPCWrappedNative @ %x with mRefCnt = %d", this, mRefCnt.get()));
    XPC_LOG_INDENT();

        if(HasProto())
        {
            if(depth && mMaybeProto)
                mMaybeProto->DebugDump(depth);
            else
                XPC_LOG_ALWAYS(("mMaybeProto @ %x", mMaybeProto));
        }
        else
            XPC_LOG_ALWAYS(("Scope @ %x", UnTagScope(mMaybeScope)));

        if(depth && mSet)
            mSet->DebugDump(depth);
        else
            XPC_LOG_ALWAYS(("mSet @ %x", mSet));

        XPC_LOG_ALWAYS(("mFlatJSObject of %x", mFlatJSObject));
        XPC_LOG_ALWAYS(("mScriptableInfo @ %x", mScriptableInfo));

        if(depth && mScriptableInfo)
        {
            XPC_LOG_INDENT();
            XPC_LOG_ALWAYS(("mScriptable @ %x", mScriptableInfo->GetCallback()));
            XPC_LOG_ALWAYS(("mFlags of %x", (PRUint32)mScriptableInfo->GetFlags()));
            XPC_LOG_ALWAYS(("mJSClass @ %x", mScriptableInfo->GetJSClass()));
            XPC_LOG_OUTDENT();
        }
    XPC_LOG_OUTDENT();
#endif
    return NS_OK;
}

/***************************************************************************/

char*
XPCWrappedNative::ToString(XPCCallContext& ccx,
                           XPCWrappedNativeTearOff* to /* = nsnull */ ) const
{
#ifdef DEBUG
#  define FMT_ADDR " @ 0x%p"
#  define FMT_STR(str) str
#  define PARAM_ADDR(w) , w
#else
#  define FMT_ADDR ""
#  define FMT_STR(str)
#  define PARAM_ADDR(w)
#endif

    char* sz = nsnull;
    char* name = nsnull;

    XPCNativeScriptableInfo* si = GetScriptableInfo();
    if(si)
        name = JS_smprintf("%s", si->GetJSClass()->name);
    if(to)
    {
        const char* fmt = name ? " (%s)" : "%s";
        name = JS_sprintf_append(name, fmt,
                                 to->GetInterface()->GetNameString());
    }
    else if(!name)
    {
        XPCNativeSet* set = GetSet();
        XPCNativeInterface** array = set->GetInterfaceArray();
        PRUint16 count = set->GetInterfaceCount();

        if(count == 1)
            name = JS_sprintf_append(name, "%s", array[0]->GetNameString());
        else if(count == 2 &&
                array[0] == XPCNativeInterface::GetISupports(ccx))
        {
            name = JS_sprintf_append(name, "%s", array[1]->GetNameString());
        }
        else
        {
            for(PRUint16 i = 0; i < count; i++)
            {
                const char* fmt = (i == 0) ?
                                    "(%s" : (i == count-1) ?
                                        ", %s)" : ", %s";
                name = JS_sprintf_append(name, fmt,
                                         array[i]->GetNameString());
            }
        }
    }

    if(!name)
    {
        return nsnull;
    }
    const char* fmt = "[xpconnect wrapped %s" FMT_ADDR FMT_STR(" (native")
        FMT_ADDR FMT_STR(")") "]";
    if(si)
    {
        fmt = "[object %s" FMT_ADDR FMT_STR(" (native") FMT_ADDR FMT_STR(")") "]";
    }
    sz = JS_smprintf(fmt, name PARAM_ADDR(this) PARAM_ADDR(mIdentity));

    JS_smprintf_free(name);


    return sz;

#undef FMT_ADDR
#undef PARAM_ADDR
}

/***************************************************************************/

#ifdef XPC_DETECT_LEADING_UPPERCASE_ACCESS_ERRORS
// static
void
XPCWrappedNative::HandlePossibleNameCaseError(JSContext* cx,
                                              XPCNativeSet* set,
                                              XPCNativeInterface* iface,
                                              jsval name)
{
    XPCCallContext ccx(JS_CALLER, cx);
    HandlePossibleNameCaseError(ccx, set, iface, name);
}

// static
void
XPCWrappedNative::HandlePossibleNameCaseError(XPCCallContext& ccx,
                                              XPCNativeSet* set,
                                              XPCNativeInterface* iface,
                                              jsval name)
{
    if(!ccx.IsValid())
        return;

    JSString* oldJSStr;
    JSString* newJSStr;
    PRUnichar* oldStr;
    PRUnichar* newStr;
    XPCNativeMember* member;
    XPCNativeInterface* localIface;

    /* PRUnichar->char->PRUnichar hack is to avoid pulling in i18n code. */
    if(JSVAL_IS_STRING(name) &&
       nsnull != (oldJSStr = JSVAL_TO_STRING(name)) &&
       nsnull != (oldStr = (PRUnichar*) JS_GetStringChars(oldJSStr)) &&
       oldStr[0] != 0 &&
       oldStr[0] >> 8 == 0 &&
       nsCRT::IsUpper((char)oldStr[0]) &&
       nsnull != (newStr = nsCRT::strdup(oldStr)))
    {
        newStr[0] = (PRUnichar) nsCRT::ToLower((char)newStr[0]);
        newJSStr = JS_NewUCStringCopyZ(ccx, (const jschar*)newStr);
        nsCRT::free(newStr);
        if(newJSStr && (set ?
             set->FindMember(STRING_TO_JSVAL(newJSStr), &member, &localIface) :
                        (JSBool)NS_PTR_TO_INT32(iface->FindMember(STRING_TO_JSVAL(newJSStr)))))
        {
            // found it!
            const char* ifaceName = localIface->GetNameString();
            const char* goodName = JS_GetStringBytes(newJSStr);
            const char* badName = JS_GetStringBytes(oldJSStr);
            char* locationStr = nsnull;

            nsIException* e = nsnull;
            nsXPCException::NewException("", NS_OK, nsnull, nsnull, &e);

            if(e)
            {
                nsresult rv;
                nsCOMPtr<nsIStackFrame> loc = nsnull;
                rv = e->GetLocation(getter_AddRefs(loc));
                if(NS_SUCCEEDED(rv) && loc) {
                    loc->ToString(&locationStr); // failure here leaves it nsnull.
                }
            }

            if(locationStr && ifaceName && goodName && badName )
            {
                printf("**************************************************\n"
                       "ERROR: JS code at [%s]\n"
                       "tried to access nonexistent property called\n"
                       "\'%s\' on interface of type \'%s\'.\n"
                       "That interface does however have a property called\n"
                       "\'%s\'. Did you mean to access that lowercase property?\n"
                       "Please fix the JS code as appropriate.\n"
                       "**************************************************\n",
                        locationStr, badName, ifaceName, goodName);
            }
            if(locationStr)
                nsMemory::Free(locationStr);
        }
    }
}
#endif

#ifdef XPC_CHECK_CLASSINFO_CLAIMS
static void DEBUG_CheckClassInfoClaims(XPCWrappedNative* wrapper)
{
    if(!wrapper || !wrapper->GetClassInfo())
        return;

    nsISupports* obj = wrapper->GetIdentityObject();
    XPCNativeSet* set = wrapper->GetSet();
    PRUint16 count = set->GetInterfaceCount();
    for(PRUint16 i = 0; i < count; i++)
    {
        nsIClassInfo* clsInfo = wrapper->GetClassInfo();
        XPCNativeInterface* iface = set->GetInterfaceAt(i);
        nsIInterfaceInfo* info = iface->GetInterfaceInfo();
        const nsIID* iid;
        nsISupports* ptr;

        info->GetIIDShared(&iid);
        nsresult rv = obj->QueryInterface(*iid, (void**)&ptr);
        if(NS_SUCCEEDED(rv))
        {
            NS_RELEASE(ptr);
            continue;
        }

        // Houston, We have a problem...

        char* className = nsnull;
        char* contractID = nsnull;
        const char* interfaceName;

        info->GetNameShared(&interfaceName);
        clsInfo->GetContractID(&contractID);
        if(wrapper->GetScriptableInfo())
        {
            wrapper->GetScriptableInfo()->GetCallback()->
                GetClassName(&className);
        }


        printf("\n!!! Object's nsIClassInfo lies about it's interfaces!!!\n"
               "   classname: %s \n"
               "   contractid: %s \n"
               "   unimplemented interface name: %s\n\n",
               className ? className : "<unknown>",
               contractID ? contractID : "<unknown>",
               interfaceName);

#ifdef XPC_ASSERT_CLASSINFO_CLAIMS
        NS_ERROR("Fix this QueryInterface or nsIClassInfo");
#endif

        if(className)
            nsMemory::Free(className);
        if(contractID)
            nsMemory::Free(contractID);
    }
}
#endif

#ifdef XPC_REPORT_SHADOWED_WRAPPED_NATIVE_MEMBERS
static void DEBUG_PrintShadowObjectInfo(const char* header,
                                        XPCNativeSet* set,
                                        XPCWrappedNative* wrapper,
                                        XPCWrappedNativeProto* proto)

{
    if(header)
        printf("%s\n", header);

    printf("   XPCNativeSet @ 0x%p for the class:\n", (void*)set);

    char* className = nsnull;
    char* contractID = nsnull;

    nsIClassInfo* clsInfo = proto ? proto->GetClassInfo() : nsnull;
    if(clsInfo)
        clsInfo->GetContractID(&contractID);

    XPCNativeScriptableInfo* si = wrapper ?
            wrapper->GetScriptableInfo() :
            proto->GetScriptableInfo();
    if(si)
        si->GetCallback()->GetClassName(&className);

    printf("   classname: %s \n"
           "   contractid: %s \n",
           className ? className : "<unknown>",
           contractID ? contractID : "<unknown>");

    if(className)
        nsMemory::Free(className);
    if(contractID)
        nsMemory::Free(contractID);

    printf("   claims to implement interfaces:\n");

    PRUint16 count = set->GetInterfaceCount();
    for(PRUint16 i = 0; i < count; i++)
    {
        XPCNativeInterface* iface = set->GetInterfaceAt(i);
        nsIInterfaceInfo* info = iface->GetInterfaceInfo();
        const char* interfaceName;
        info->GetNameShared(&interfaceName);
        printf("      %s\n", interfaceName);
    }
}

static void ReportSingleMember(jsval ifaceName,
                               jsval memberName)
{
    if(JSVAL_IS_STRING(memberName))
        printf("%s::%s", JS_GetStringBytes(JSVAL_TO_STRING(ifaceName)),
                         JS_GetStringBytes(JSVAL_TO_STRING(memberName)));
    else
        printf("%s", JS_GetStringBytes(JSVAL_TO_STRING(ifaceName)));
}

static void ShowHeader(JSBool* printedHeader,
                       const char* header,
                       XPCNativeSet* set,
                       XPCWrappedNative* wrapper,
                       XPCWrappedNativeProto* proto)
{
    if(!*printedHeader)
    {
        DEBUG_PrintShadowObjectInfo(header, set, wrapper, proto);
        *printedHeader = JS_TRUE;
    }

}

static void ShowOneShadow(jsval ifaceName1,
                          jsval memberName1,
                          jsval ifaceName2,
                          jsval memberName2)
{
    ReportSingleMember(ifaceName1, memberName1);
    printf(" shadows ");
    ReportSingleMember(ifaceName2, memberName2);
    printf("\n");
}

static void ShowDuplicateInterface(jsval ifaceName)
{
    printf(" ! %s appears twice in the nsIClassInfo interface set!\n",
           JS_GetStringBytes(JSVAL_TO_STRING(ifaceName)));
}

static JSBool InterfacesAreRelated(XPCNativeInterface* iface1,
                                   XPCNativeInterface* iface2)
{
    nsIInterfaceInfo* info1 = iface1->GetInterfaceInfo();
    nsIInterfaceInfo* info2 = iface2->GetInterfaceInfo();

    NS_ASSERTION(info1 != info2, "should not have different iface!");

    PRBool match;

    return
        (NS_SUCCEEDED(info1->HasAncestor(iface2->GetIID(), &match)) && match) ||
        (NS_SUCCEEDED(info2->HasAncestor(iface1->GetIID(), &match)) && match);
}

static JSBool MembersAreTheSame(XPCNativeInterface* iface1,
                                PRUint16 memberIndex1,
                                XPCNativeInterface* iface2,
                                PRUint16 memberIndex2)
{
    nsIInterfaceInfo* info1 = iface1->GetInterfaceInfo();
    nsIInterfaceInfo* info2 = iface2->GetInterfaceInfo();

    XPCNativeMember* member1 = iface1->GetMemberAt(memberIndex1);
    XPCNativeMember* member2 = iface2->GetMemberAt(memberIndex2);

    PRUint16 index1 = member1->GetIndex();
    PRUint16 index2 = member2->GetIndex();

    // If they are both constants, then we'll just be sure that they are equivalent.

    if(member1->IsConstant())
    {
        if(!member2->IsConstant())
            return JS_FALSE;

        const nsXPTConstant* constant1;
        const nsXPTConstant* constant2;

        return NS_SUCCEEDED(info1->GetConstant(index1, &constant1)) &&
               NS_SUCCEEDED(info2->GetConstant(index2, &constant2)) &&
               constant1->GetType() == constant2->GetType() &&
               constant1->GetValue() == constant2->GetValue();
    }

    // Else we make sure they are of the same 'type' and return true only if
    // they are inherited from the same interface.

    if(member1->IsMethod() != member2->IsMethod() ||
       member1->IsWritableAttribute() != member2->IsWritableAttribute() ||
       member1->IsReadOnlyAttribute() != member2->IsReadOnlyAttribute())
    {
        return JS_FALSE;
    }

    const nsXPTMethodInfo* mi1;
    const nsXPTMethodInfo* mi2;

    return NS_SUCCEEDED(info1->GetMethodInfo(index1, &mi1)) &&
           NS_SUCCEEDED(info2->GetMethodInfo(index2, &mi2)) &&
           mi1 == mi2;
}

void DEBUG_ReportShadowedMembers(XPCNativeSet* set,
                                 XPCWrappedNative* wrapper,
                                 XPCWrappedNativeProto* proto)
{
    // NOTE: Either wrapper or proto could be null...

    if(!(proto || wrapper) || !set || set->GetInterfaceCount() < 2)
        return;

    NS_ASSERTION(proto || wrapper, "bad param!");
    XPCJSRuntime* rt = proto ? proto->GetRuntime() : wrapper->GetRuntime();

    // a quicky hack to avoid reporting info for the same set too often
    static int nextSeenSet = 0;
    static const int MAX_SEEN_SETS = 128;
    static XPCNativeSet* SeenSets[MAX_SEEN_SETS];
    for(int seen = 0; seen < MAX_SEEN_SETS; seen++)
        if(set == SeenSets[seen])
            return;
    SeenSets[nextSeenSet] = set;

#ifdef off_DEBUG_jband
    static int seenCount = 0;
    printf("--- adding SeenSets[%d] = 0x%p\n", nextSeenSet, set);
    DEBUG_PrintShadowObjectInfo(nsnull, set, wrapper, proto);
#endif
    int localNext = nextSeenSet+1;
    nextSeenSet = localNext < MAX_SEEN_SETS ? localNext : 0;

    XPCNativeScriptableInfo* si = wrapper ?
            wrapper->GetScriptableInfo() :
            proto->GetScriptableInfo();

    // We just want to skip some classes...
    if(si)
    {
        // Add any classnames to skip to this (null terminated) array...
        static const char* skipClasses[] = {
            "Window",
            "HTMLDocument",
            "HTMLCollection",
            "Event",
            "ChromeWindow",
            nsnull
        };

        static PRBool warned = JS_FALSE;
        if(!warned)
        {
            printf("!!! XPConnect won't warn about Shadowed Members of...\n  ");
            for(const char** name = skipClasses; *name; name++)
                printf("%s %s", name == skipClasses ? "" : ",", *name);
             printf("\n");
            warned = JS_TRUE;
        }

        PRBool quit = JS_FALSE;
        char* className = nsnull;
        si->GetCallback()->GetClassName(&className);
        if(className)
        {
            for(const char** name = skipClasses; *name; name++)
            {
                if(!strcmp(*name, className))
                {
                    quit = JS_TRUE;
                    break;
                }
            }
            nsMemory::Free(className);
        }
        if(quit)
            return;
    }

    const char header[] =
        "!!!Object wrapped by XPConnect has members whose names shadow each other!!!";

    JSBool printedHeader = JS_FALSE;

    jsval QIName = rt->GetStringJSVal(XPCJSRuntime::IDX_QUERY_INTERFACE);

    PRUint16 ifaceCount = set->GetInterfaceCount();
    PRUint16 i, j, k, m;

    // First look for duplicate interface entries

    for(i = 0; i < ifaceCount; i++)
    {
        XPCNativeInterface* ifaceOuter = set->GetInterfaceAt(i);
        for(k = i+1; k < ifaceCount; k++)
        {
            XPCNativeInterface* ifaceInner = set->GetInterfaceAt(k);
            if(ifaceInner == ifaceOuter)
            {
                ShowHeader(&printedHeader, header, set, wrapper, proto);
                ShowDuplicateInterface(ifaceOuter->GetName());
            }
        }
    }

    // Now scan for shadowing names

    for(i = 0; i < ifaceCount; i++)
    {
        XPCNativeInterface* ifaceOuter = set->GetInterfaceAt(i);
        jsval ifaceOuterName = ifaceOuter->GetName();

        PRUint16 memberCountOuter = ifaceOuter->GetMemberCount();
        for(j = 0; j < memberCountOuter; j++)
        {
            XPCNativeMember* memberOuter = ifaceOuter->GetMemberAt(j);
            jsval memberOuterName = memberOuter->GetName();

            if(memberOuterName == QIName)
                continue;

            for(k = i+1; k < ifaceCount; k++)
            {
                XPCNativeInterface* ifaceInner = set->GetInterfaceAt(k);
                jsval ifaceInnerName = ifaceInner->GetName();

                // Reported elsewhere.
                if(ifaceInner == ifaceOuter)
                    continue;

                // We consider this not worth reporting because callers will
                // almost certainly be getting what they expect.
                if(InterfacesAreRelated(ifaceInner, ifaceOuter))
                    continue;

                if(ifaceInnerName == memberOuterName)
                {
                    ShowHeader(&printedHeader, header, set, wrapper, proto);
                    ShowOneShadow(ifaceInnerName, JSVAL_NULL,
                                  ifaceOuterName, memberOuterName);
                }

                PRUint16 memberCountInner = ifaceInner->GetMemberCount();

                for(m = 0; m < memberCountInner; m++)
                {
                    XPCNativeMember* memberInner = ifaceInner->GetMemberAt(m);
                    jsval memberInnerName = memberInner->GetName();

                    if(memberInnerName == QIName)
                        continue;

                    if(memberOuterName == memberInnerName &&
                       !MembersAreTheSame(ifaceOuter, j, ifaceInner, m))

                    {
                        ShowHeader(&printedHeader, header, set, wrapper, proto);
                        ShowOneShadow(ifaceOuterName, memberOuterName,
                                      ifaceInnerName, memberInnerName);
                    }
                }
            }
        }
    }
}
#endif

#ifdef XPC_CHECK_WRAPPER_THREADSAFETY
void DEBUG_ReportWrapperThreadSafetyError(XPCCallContext& ccx,
                                          const char* msg,
                                          const XPCWrappedNative* wrapper)
{
    XPCPerThreadData* tls = ccx.GetThreadData();
    if(1 != tls->IncrementWrappedNativeThreadsafetyReportDepth())
        return;

    printf("---------------------------------------------------------------\n");
    printf("!!!!! XPConnect wrapper thread use error...\n");

    char* wrapperDump = wrapper->ToString(ccx);
    if(wrapperDump)
    {
        printf("  %s\n  wrapper: %s\n", msg, wrapperDump);
        JS_smprintf_free(wrapperDump);
    }
    else
        printf("  %s\n  wrapper @ 0x%p\n", msg, (void *)wrapper);

    printf("  JS call stack...\n");
    xpc_DumpJSStack(ccx, JS_TRUE, JS_TRUE, JS_TRUE);
    printf("---------------------------------------------------------------\n");
    
    tls->ClearWrappedNativeThreadsafetyReportDepth();
}

void DEBUG_CheckWrapperThreadSafety(const XPCWrappedNative* wrapper)
{
    XPCWrappedNativeProto* proto = wrapper->GetProto();
    if(proto && proto->ClassIsThreadSafe())
        return;

    PRThread* currentThread = PR_GetCurrentThread();

    if(proto && proto->ClassIsMainThreadOnly())
    {
        if(currentThread != wrapper->gMainThread)
        {
            XPCCallContext ccx(NATIVE_CALLER);
            DEBUG_ReportWrapperThreadSafetyError(ccx,
                "Main Thread Only wrapper accessed on another thread", wrapper);
        }
    }
    else if(currentThread != wrapper->mThread)
    {
        XPCCallContext ccx(NATIVE_CALLER);
        DEBUG_ReportWrapperThreadSafetyError(ccx,
            "XPConnect WrappedNative is being accessed on multiple threads but "
            "the underlying native xpcom object does not have a "
            "nsIClassInfo with the 'THREADSAFE' flag set", wrapper);
    }
}
#endif

NS_IMPL_THREADSAFE_ISUPPORTS1(XPCJSObjectHolder, nsIXPConnectJSObjectHolder)

NS_IMETHODIMP
XPCJSObjectHolder::GetJSObject(JSObject** aJSObj)
{
    NS_PRECONDITION(aJSObj, "bad param");
    NS_PRECONDITION(mJSObj, "bad object state");
    *aJSObj = mJSObj;
    return NS_OK;
}

XPCJSObjectHolder::XPCJSObjectHolder(JSContext* cx, JSObject* obj)
    : mRuntime(JS_GetRuntime(cx)), mJSObj(obj)
{
    JS_AddNamedRoot(cx, &mJSObj, "XPCJSObjectHolder::mJSObj");
}

XPCJSObjectHolder::~XPCJSObjectHolder()
{
    JS_RemoveRootRT(mRuntime, &mJSObj);
}

XPCJSObjectHolder*
XPCJSObjectHolder::newHolder(JSContext* cx, JSObject* obj)
{
    if(!cx || !obj)
    {
        NS_ASSERTION(0, "bad param");
        return nsnull;
    }
    return new XPCJSObjectHolder(cx, obj);
}
