gecko/js/xpconnect/src/XPCWrappedNativeProto.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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 * 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.
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 * Contributor(s):
 *   John Bandhauer <jband@netscape.com> (original author)
 *
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/* Possibly shared proto object for XPCWrappedNative. */

#include "xpcprivate.h"

#if defined(DEBUG_xpc_hacker) || defined(DEBUG)
PRInt32 XPCWrappedNativeProto::gDEBUG_LiveProtoCount = 0;
#endif

XPCWrappedNativeProto::XPCWrappedNativeProto(XPCWrappedNativeScope* Scope,
                                             nsIClassInfo* ClassInfo,
                                             PRUint32 ClassInfoFlags,
                                             XPCNativeSet* Set,
                                             QITableEntry* offsets)
    : mScope(Scope),
      mJSProtoObject(nsnull),
      mClassInfo(ClassInfo),
      mClassInfoFlags(ClassInfoFlags),
      mSet(Set),
      mSecurityInfo(nsnull),
      mScriptableInfo(nsnull),
      mOffsets(offsets)
{
    // This native object lives as long as its associated JSObject - killed
    // by finalization of the JSObject (or explicitly if Init fails).

    MOZ_COUNT_CTOR(XPCWrappedNativeProto);

#ifdef DEBUG
    PR_ATOMIC_INCREMENT(&gDEBUG_LiveProtoCount);
#endif
}

XPCWrappedNativeProto::~XPCWrappedNativeProto()
{
    NS_ASSERTION(!mJSProtoObject, "JSProtoObject still alive");

    MOZ_COUNT_DTOR(XPCWrappedNativeProto);

#ifdef DEBUG
    PR_ATOMIC_DECREMENT(&gDEBUG_LiveProtoCount);
#endif

    // Note that our weak ref to mScope is not to be trusted at this point.

    XPCNativeSet::ClearCacheEntryForClassInfo(mClassInfo);

    delete mScriptableInfo;
}

JSBool
XPCWrappedNativeProto::Init(XPCCallContext& ccx,
                            JSBool isGlobal,
                            const XPCNativeScriptableCreateInfo* scriptableCreateInfo)
{
    nsIXPCScriptable *callback = scriptableCreateInfo ?
                                 scriptableCreateInfo->GetCallback() :
                                 nsnull;
    if (callback) {
        mScriptableInfo =
            XPCNativeScriptableInfo::Construct(ccx, isGlobal, scriptableCreateInfo);
        if (!mScriptableInfo)
            return JS_FALSE;
    }

    js::Class* jsclazz;


    if (mScriptableInfo) {
        const XPCNativeScriptableFlags& flags(mScriptableInfo->GetFlags());

        if (flags.AllowPropModsToPrototype()) {
            jsclazz = flags.WantCall() ?
                &XPC_WN_ModsAllowed_WithCall_Proto_JSClass :
                &XPC_WN_ModsAllowed_NoCall_Proto_JSClass;
        } else {
            jsclazz = flags.WantCall() ?
                &XPC_WN_NoMods_WithCall_Proto_JSClass :
                &XPC_WN_NoMods_NoCall_Proto_JSClass;
        }
    } else {
        jsclazz = &XPC_WN_NoMods_NoCall_Proto_JSClass;
    }

    JSObject *parent = mScope->GetGlobalJSObject();

    mJSProtoObject =
        xpc_NewSystemInheritingJSObject(ccx, js::Jsvalify(jsclazz),
                                        mScope->GetPrototypeJSObject(),
                                        true, parent);

    JSBool ok = mJSProtoObject && JS_SetPrivate(ccx, mJSProtoObject, this);

    if (ok && callback) {
        nsresult rv = callback->PostCreatePrototype(ccx, mJSProtoObject);
        if (NS_FAILED(rv)) {
            JS_SetPrivate(ccx, mJSProtoObject, nsnull);
            mJSProtoObject = nsnull;
            XPCThrower::Throw(rv, ccx);
            return JS_FALSE;
        }
    }

    DEBUG_ReportShadowedMembers(mSet, nsnull, this);

    return ok;
}

void
XPCWrappedNativeProto::JSProtoObjectFinalized(JSContext *cx, JSObject *obj)
{
    NS_ASSERTION(obj == mJSProtoObject, "huh?");

    // Map locking is not necessary since we are running gc.

    if (IsShared()) {
        // Only remove this proto from the map if it is the one in the map.
        ClassInfo2WrappedNativeProtoMap* map =
            GetScope()->GetWrappedNativeProtoMap(ClassIsMainThreadOnly());
        if (map->Find(mClassInfo) == this)
            map->Remove(mClassInfo);
    }

    GetRuntime()->GetDetachedWrappedNativeProtoMap()->Remove(this);
    GetRuntime()->GetDyingWrappedNativeProtoMap()->Add(this);

    mJSProtoObject = nsnull;
}

void
XPCWrappedNativeProto::SystemIsBeingShutDown(JSContext* cx)
{
    // Note that the instance might receive this call multiple times
    // as we walk to here from various places.

#ifdef XPC_TRACK_PROTO_STATS
    static bool DEBUG_DumpedStats = false;
    if (!DEBUG_DumpedStats) {
        printf("%d XPCWrappedNativeProto(s) alive at shutdown\n",
               gDEBUG_LiveProtoCount);
        DEBUG_DumpedStats = true;
    }
#endif

    if (mJSProtoObject) {
        // short circuit future finalization
        JS_SetPrivate(cx, mJSProtoObject, nsnull);
        mJSProtoObject = nsnull;
    }
}

// static
XPCWrappedNativeProto*
XPCWrappedNativeProto::GetNewOrUsed(XPCCallContext& ccx,
                                    XPCWrappedNativeScope* Scope,
                                    nsIClassInfo* ClassInfo,
                                    const XPCNativeScriptableCreateInfo* ScriptableCreateInfo,
                                    JSBool ForceNoSharing,
                                    JSBool isGlobal,
                                    QITableEntry* offsets)
{
    NS_ASSERTION(Scope, "bad param");
    NS_ASSERTION(ClassInfo, "bad param");

    AutoMarkingWrappedNativeProtoPtr proto(ccx);
    ClassInfo2WrappedNativeProtoMap* map = nsnull;
    XPCLock* lock = nsnull;
    JSBool shared;

    JSUint32 ciFlags;
    if (NS_FAILED(ClassInfo->GetFlags(&ciFlags)))
        ciFlags = 0;

    if (ciFlags & XPC_PROTO_DONT_SHARE) {
        NS_ERROR("reserved flag set!");
        ciFlags &= ~XPC_PROTO_DONT_SHARE;
    }

    if (ForceNoSharing || (ciFlags & nsIClassInfo::PLUGIN_OBJECT) ||
        (ScriptableCreateInfo &&
         ScriptableCreateInfo->GetFlags().DontSharePrototype())) {
        ciFlags |= XPC_PROTO_DONT_SHARE;
        shared = JS_FALSE;
    } else {
        shared = JS_TRUE;
    }

    if (shared) {
        JSBool mainThreadOnly = !!(ciFlags & nsIClassInfo::MAIN_THREAD_ONLY);
        map = Scope->GetWrappedNativeProtoMap(mainThreadOnly);
        lock = mainThreadOnly ? nsnull : Scope->GetRuntime()->GetMapLock();
        {   // scoped lock
            XPCAutoLock al(lock);
            proto = map->Find(ClassInfo);
            if (proto)
                return proto;
        }
    }

    AutoMarkingNativeSetPtr set(ccx);
    set = XPCNativeSet::GetNewOrUsed(ccx, ClassInfo);
    if (!set)
        return nsnull;

    proto = new XPCWrappedNativeProto(Scope, ClassInfo, ciFlags, set, offsets);

    if (!proto || !proto->Init(ccx, isGlobal, ScriptableCreateInfo)) {
        delete proto.get();
        return nsnull;
    }

    if (shared)
    {   // scoped lock
        XPCAutoLock al(lock);
        map->Add(ClassInfo, proto);
    }

    return proto;
}

void
XPCWrappedNativeProto::DebugDump(PRInt16 depth)
{
#ifdef DEBUG
    depth-- ;
    XPC_LOG_ALWAYS(("XPCWrappedNativeProto @ %x", this));
    XPC_LOG_INDENT();
        XPC_LOG_ALWAYS(("gDEBUG_LiveProtoCount is %d", gDEBUG_LiveProtoCount));
        XPC_LOG_ALWAYS(("mScope @ %x", mScope));
        XPC_LOG_ALWAYS(("mJSProtoObject @ %x", mJSProtoObject));
        XPC_LOG_ALWAYS(("mSet @ %x", mSet));
        XPC_LOG_ALWAYS(("mSecurityInfo of %x", mSecurityInfo));
        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
}