Oilpan: Prepare moving InspectorController and InspectorAgents to oilpan.

Source/core/inspector/WorkerDebuggerAgent.cpp

Index: Source/core/inspector/WorkerDebuggerAgent.cpp
diff --git a/Source/core/inspector/WorkerDebuggerAgent.cpp b/Source/core/inspector/WorkerDebuggerAgent.cpp
index 52d2b4d4f5c01e4badba956ba1125f152e94843d..adcacce4c06c65d6b851dc5e50c311d0f2d1e51c 100644
--- a/Source/core/inspector/WorkerDebuggerAgent.cpp
+++ b/Source/core/inspector/WorkerDebuggerAgent.cpp
@@ -46,7 +46,11 @@ Mutex& workerDebuggerAgentsMutex()
     return mutex;
 }
 
+#if ENABLE(OILPAN)
+typedef HashMap<WorkerThread*, OwnPtr<CrossThreadPersistent<WorkerDebuggerAgent> > > WorkerDebuggerAgents;

[haraken, 2014/06/12 08:40:25]

Why does this need to be OwnPtr<CrossThreadPersistent<X>> instead of
CrossThreadPersistent<X>?

In the first place, I don't fully understand how the WorkerDebuggerAgents should
work. Would you elaborate on who adds/removes entries to/from the map when?

I guess this map can just be PersistentHashMap<WorkerThread*,
WeakMember<WorkerDebuggerAgent>>.

[keishi, 2014/06/13 03:37:34]

I get this error because CrossThreadPersistent doesn't have a default
constructor.
../../third_party/WebKit/Source/wtf/HashTraits.h:83:40: error: no matching
constructor for initialization of
'WebCore::CrossThreadPersistent<WebCore::WorkerDebuggerAgent>'
        static T emptyValue() { return T(); }
WorkerDebuggerAgent is created when the WorkerThread starts.
When a WorkerDebuggerAgent is created it adds itself to the map.
We need to remove it from the map when the WorkerDebuggerAgent is destroyed,
which is when the WorkerThread is stopping.

The map is used when the user runs JavaScript in the worker using the debugger.
The task to run the debugger javascript is added to the worker run loop from the
main thread.
Then we use the map to lookup the WorkerDebuggerAgent for that worker in order
to find the WorkerScriptDebugServer.
WorkerScriptDebugServer executes the javascript.

Now that I said this it looks like this map could be removed so I removed it in
this next patch.
According to https://codereview.chromium.org/307943002/#msg10
We can't use PersistentHeapHashMap because the backing store might be owned by a
worker thread.
I tried using CrossThreadPersistent<HeapHashMap<WorkerThread*,
WeakMember<WorkerDebuggerAgent> > > but I still got a crash.

[haraken, 2014/06/13 08:02:53]

I'm not quite sure what you're planning, but if you're planning to remove it,
that's great. Let's add a FIXME.

According to your analysis, it seems that we can just make the WorkerThread hold
a persistent handle to WorkerDebuggerAgent.

[keishi, 2014/06/17 03:13:22]

I've already removed the map in my CL.

+#else
 typedef HashMap<WorkerThread*, WorkerDebuggerAgent*> WorkerDebuggerAgents;
+#endif
 
 WorkerDebuggerAgents& workerDebuggerAgents()
 {
@@ -54,7 +58,6 @@ WorkerDebuggerAgents& workerDebuggerAgents()
     return agents;
 }
 
-
 class RunInspectorCommandsTask FINAL : public ScriptDebugServer::Task {
 public:
     explicit RunInspectorCommandsTask(WorkerThread* thread)
@@ -73,35 +76,57 @@ private:
 
 } // namespace
 
-PassOwnPtr<WorkerDebuggerAgent> WorkerDebuggerAgent::create(WorkerScriptDebugServer* scriptDebugServer, WorkerGlobalScope* inspectedWorkerGlobalScope, InjectedScriptManager* injectedScriptManager)
+PassOwnPtrWillBeRawPtr<WorkerDebuggerAgent> WorkerDebuggerAgent::create(WorkerScriptDebugServer* scriptDebugServer, WorkerGlobalScope* inspectedWorkerGlobalScope, InjectedScriptManager* injectedScriptManager)
 {
-    return adoptPtr(new WorkerDebuggerAgent(scriptDebugServer, inspectedWorkerGlobalScope, injectedScriptManager));
+    return adoptPtrWillBeNoop(new WorkerDebuggerAgent(scriptDebugServer, inspectedWorkerGlobalScope, injectedScriptManager));
 }
 
 WorkerDebuggerAgent::WorkerDebuggerAgent(WorkerScriptDebugServer* scriptDebugServer, WorkerGlobalScope* inspectedWorkerGlobalScope, InjectedScriptManager* injectedScriptManager)
     : InspectorDebuggerAgent(injectedScriptManager)
     , m_scriptDebugServer(scriptDebugServer)
     , m_inspectedWorkerGlobalScope(inspectedWorkerGlobalScope)
+    , m_thread(inspectedWorkerGlobalScope->thread())
 {
     MutexLocker lock(workerDebuggerAgentsMutex());
-    workerDebuggerAgents().set(inspectedWorkerGlobalScope->thread(), this);
+#if ENABLE(OILPAN)
+    workerDebuggerAgents().set(m_thread, adoptPtr(new CrossThreadPersistent<WorkerDebuggerAgent>(this)));
+#else
+    workerDebuggerAgents().set(m_thread, this);
+#endif
 }
 
 WorkerDebuggerAgent::~WorkerDebuggerAgent()
 {
-    MutexLocker lock(workerDebuggerAgentsMutex());
-    ASSERT(workerDebuggerAgents().contains(m_inspectedWorkerGlobalScope->thread()));
-    workerDebuggerAgents().remove(m_inspectedWorkerGlobalScope->thread());
+}
+
+void WorkerDebuggerAgent::trace(Visitor* visitor)
+{
+    visitor->trace(m_inspectedWorkerGlobalScope);
+    InspectorDebuggerAgent::trace(visitor);
 }
 
 void WorkerDebuggerAgent::interruptAndDispatchInspectorCommands(WorkerThread* thread)
 {
     MutexLocker lock(workerDebuggerAgentsMutex());
+#if ENABLE(OILPAN)
+    CrossThreadPersistent<WorkerDebuggerAgent>* agentHandle = workerDebuggerAgents().get(thread);
+    if (!agentHandle)
+        return;
+    WorkerDebuggerAgent* agent = agentHandle->get();
+#else
     WorkerDebuggerAgent* agent = workerDebuggerAgents().get(thread);
+#endif
     if (agent)
         agent->m_scriptDebugServer->interruptAndRunTask(adoptPtr(new RunInspectorCommandsTask(thread)));
 }
 
+void WorkerDebuggerAgent::discard()
+{
+    MutexLocker lock(workerDebuggerAgentsMutex());
+    ASSERT(workerDebuggerAgents().contains(m_thread));
+    workerDebuggerAgents().remove(m_thread);
+}
+
 void WorkerDebuggerAgent::startListeningScriptDebugServer()
 {
     scriptDebugServer().addListener(this);