Bug 641685 - Make plugin object map a singleton in the plugin process (r=bsmedberg)

This patches moves the object map (which tracks the PluginScriptableObjectChild
and PluginInstanceChild for a given NPObject) from the PluginModuleChild to
a global variable. This change prepares the way for having multiple PluginModuleChild
instances in a given plugin process.

dom/plugins/ipc/PluginScriptableObjectChild.cpp

@@ -539,7 +539,7 @@ PluginScriptableObjectChild::~PluginScriptableObjectChild()
   AssertPluginThread();
 
   if (mObject) {
-    PluginModuleChild::current()->UnregisterActorForNPObject(mObject);
+    UnregisterActor(mObject);
 
     if (mObject->_class == GetClass()) {
       NS_ASSERTION(mType == Proxy, "Wrong type!");
@@ -569,8 +569,8 @@ PluginScriptableObjectChild::InitializeProxy()
     return false;
   }
 
-  if (!PluginModuleChild::current()->RegisterActorForNPObject(object, this)) {
-    NS_ERROR("RegisterActorForNPObject failed");
+  if (!RegisterActor(object)) {
+    NS_ERROR("RegisterActor failed");
     return false;
   }
 
@@ -594,8 +594,8 @@ PluginScriptableObjectChild::InitializeLocal(NPObject* aObject)
   NS_ASSERTION(!mProtectCount, "Should be zero!");
   mProtectCount++;
 
-  if (!PluginModuleChild::current()->RegisterActorForNPObject(aObject, this)) {
-    NS_ERROR("RegisterActorForNPObject failed");
+  if (!RegisterActor(aObject)) {
+    NS_ERROR("RegisterActor failed");
   }
 
   mObject = aObject;
@@ -688,7 +688,7 @@ PluginScriptableObjectChild::DropNPObject()
 
   // We think we're about to be deleted, but we could be racing with the other
   // process.
-  PluginModuleChild::current()->UnregisterActorForNPObject(mObject);
+  UnregisterActor(mObject);
   mObject = nullptr;
 
   SendUnprotect();
@@ -1181,3 +1181,105 @@ PluginScriptableObjectChild::Evaluate(NPString* aScript,
   ConvertToVariant(result, *aResult);
   return true;
 }
+
+nsTHashtable<PluginScriptableObjectChild::NPObjectData>* PluginScriptableObjectChild::sObjectMap;
+
+bool
+PluginScriptableObjectChild::RegisterActor(NPObject* aObject)
+{
+  AssertPluginThread();
+  MOZ_ASSERT(aObject, "Null pointer!");
+
+  NPObjectData* d = sObjectMap->GetEntry(aObject);
+  if (!d) {
+    NS_ERROR("NPObject not in object table");
+    return false;
+  }
+
+  d->actor = this;
+  return true;
+}
+
+void
+PluginScriptableObjectChild::UnregisterActor(NPObject* aObject)
+{
+  AssertPluginThread();
+  MOZ_ASSERT(aObject, "Null pointer!");
+
+  NPObjectData* d = sObjectMap->GetEntry(aObject);
+  MOZ_ASSERT(d, "NPObject not in object table");
+  if (d) {
+    d->actor = nullptr;
+  }
+}
+
+/* static */ PluginScriptableObjectChild*
+PluginScriptableObjectChild::GetActorForNPObject(NPObject* aObject)
+{
+  AssertPluginThread();
+  MOZ_ASSERT(aObject, "Null pointer!");
+
+  NPObjectData* d = sObjectMap->GetEntry(aObject);
+  if (!d) {
+    NS_ERROR("Plugin using object not created with NPN_CreateObject?");
+    return nullptr;
+  }
+
+  return d->actor;
+}
+
+/* static */ void
+PluginScriptableObjectChild::RegisterObject(NPObject* aObject, PluginInstanceChild* aInstance)
+{
+  AssertPluginThread();
+
+  if (!sObjectMap) {
+    sObjectMap = new nsTHashtable<PluginScriptableObjectChild::NPObjectData>();
+  }
+
+  NPObjectData* d = sObjectMap->PutEntry(aObject);
+  MOZ_ASSERT(!d->instance, "New NPObject already mapped?");
+  d->instance = aInstance;
+}
+
+/* static */ void
+PluginScriptableObjectChild::UnregisterObject(NPObject* aObject)
+{
+  AssertPluginThread();
+
+  sObjectMap->RemoveEntry(aObject);
+
+  if (!sObjectMap->Count()) {
+    delete sObjectMap;
+    sObjectMap = nullptr;
+  }
+}
+
+/* static */ PluginInstanceChild*
+PluginScriptableObjectChild::GetInstanceForNPObject(NPObject* aObject)
+{
+  AssertPluginThread();
+  NPObjectData* d = sObjectMap->GetEntry(aObject);
+  if (!d) {
+    return nullptr;
+  }
+  return d->instance;
+}
+
+/* static */ PLDHashOperator
+PluginScriptableObjectChild::CollectForInstance(NPObjectData* d, void* userArg)
+{
+    PluginInstanceChild* instance = static_cast<PluginInstanceChild*>(userArg);
+    if (d->instance == instance) {
+        NPObject* o = d->GetKey();
+        instance->mDeletingHash->PutEntry(o);
+    }
+    return PL_DHASH_NEXT;
+}
+
+/* static */ void
+PluginScriptableObjectChild::NotifyOfInstanceShutdown(PluginInstanceChild* aInstance)
+{
+  AssertPluginThread();
+  sObjectMap->EnumerateEntries(CollectForInstance, aInstance);
+}