js/ipc/JavaScriptChild.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=4 sw=4 et tw=80:
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "JavaScriptChild.h"
   9 #include "mozilla/dom/ContentChild.h"
  10 #include "mozilla/dom/BindingUtils.h"
  11 #include "mozilla/ipc/MessageChannel.h"
  12 #include "nsContentUtils.h"
  13 #include "xpcprivate.h"
  14 #include "jsfriendapi.h"
  15 #include "AccessCheck.h"
  16
  17 using namespace JS;
  18 using namespace mozilla;
  19 using namespace mozilla::jsipc;
  20
  21 using mozilla::AutoSafeJSContext;
  22
  23 static void
  24 UpdateChildWeakPointersAfterGC(JSRuntime* rt, void* data)
  25 {
  26     static_cast<JavaScriptChild*>(data)->updateWeakPointers();
  27 }
  28
  29 JavaScriptChild::JavaScriptChild(JSRuntime* rt)
  30   : JavaScriptShared(rt),
  31     JavaScriptBase<PJavaScriptChild>(rt)
  32 {
  33 }
  34
  35 JavaScriptChild::~JavaScriptChild()
  36 {
  37     JS_RemoveWeakPointerCallback(rt_, UpdateChildWeakPointersAfterGC);
  38 }
  39
  40 bool
  41 JavaScriptChild::init()
  42 {
  43     if (!WrapperOwner::init())
  44         return false;
  45     if (!WrapperAnswer::init())
  46         return false;
  47
  48     JS_AddWeakPointerCallback(rt_, UpdateChildWeakPointersAfterGC, this);
  49     return true;
  50 }
  51
  52 void
  53 JavaScriptChild::updateWeakPointers()
  54 {
  55     objects_.sweep();
  56     unwaivedObjectIds_.sweep();
  57     waivedObjectIds_.sweep();
  58 }
  59
  60 JSObject*
  61 JavaScriptChild::scopeForTargetObjects()
  62 {
  63     // CPOWs from the parent need to point into the child's privileged junk
  64     // scope so that they can benefit from XrayWrappers in the child.
  65     return xpc::PrivilegedJunkScope();
  66 }