From 53a373287d35610a17d463ea58aec96137d83d7a Mon Sep 17 00:00:00 2001
From: Andrea Marchesini <amarchesini@mozilla.com>
Date: Mon, 18 Jun 2018 16:37:21 -0400
Subject: [PATCH] Bug 1455256 - Port more components to WorkerRef - part 2 -
 IPCStream, r=asuth

---
 ipc/glue/IPCStreamSource.cpp | 39 +++++++++++-------------------------
 ipc/glue/IPCStreamSource.h   | 14 +++----------
 2 files changed, 15 insertions(+), 38 deletions(-)

diff --git a/ipc/glue/IPCStreamSource.cpp b/ipc/glue/IPCStreamSource.cpp
index 48995e381b5f..8587d142e59e 100644
--- a/ipc/glue/IPCStreamSource.cpp
+++ b/ipc/glue/IPCStreamSource.cpp
@@ -14,8 +14,6 @@
 #include "nsStreamUtils.h"
 #include "nsThreadUtils.h"
 
-using mozilla::dom::WorkerPrivate;
-using mozilla::dom::WorkerStatus;
 using mozilla::wr::ByteBuffer;
 
 namespace mozilla {
@@ -43,7 +41,7 @@ public:
 
     // If this fails, then it means the owning thread is a Worker that has
     // been shutdown.  Its ok to lose the event in this case because the
-    // IPCStreamChild listens for this event through the WorkerHolder.
+    // IPCStreamChild listens for this event through the WorkerRef.
     nsresult rv = mOwningEventTarget->Dispatch(this, nsIThread::DISPATCH_NORMAL);
     if (NS_FAILED(rv)) {
       NS_WARNING("Failed to dispatch stream readable event to owning thread");
@@ -67,7 +65,7 @@ public:
   {
     // Cancel() gets called when the Worker thread is being shutdown.  We have
     // nothing to do here because IPCStreamChild handles this case via
-    // the WorkerHolder.
+    // the WorkerRef.
     return NS_OK;
   }
 
@@ -103,9 +101,7 @@ NS_IMPL_ISUPPORTS(IPCStreamSource::Callback, nsIInputStreamCallback,
                                              nsICancelableRunnable);
 
 IPCStreamSource::IPCStreamSource(nsIAsyncInputStream* aInputStream)
-  : WorkerHolder("IPCStreamSource")
-  , mStream(aInputStream)
-  , mWorkerPrivate(nullptr)
+  : mStream(aInputStream)
   , mState(ePending)
 {
   MOZ_ASSERT(aInputStream);
@@ -116,7 +112,7 @@ IPCStreamSource::~IPCStreamSource()
   NS_ASSERT_OWNINGTHREAD(IPCStreamSource);
   MOZ_ASSERT(mState == eClosed);
   MOZ_ASSERT(!mCallback);
-  MOZ_ASSERT(!mWorkerPrivate);
+  MOZ_ASSERT(!mWorkerRef);
 }
 
 bool
@@ -133,19 +129,20 @@ IPCStreamSource::Initialize()
   // A source can be used on any thread, but we only support IPCStream on
   // main thread, Workers and PBackground thread right now.  This is due
   // to the requirement  that the thread be guaranteed to live long enough to
-  // receive messages. We can enforce this guarantee with a WorkerHolder on
+  // receive messages. We can enforce this guarantee with a StrongWorkerRef on
   // worker threads, but not other threads. Main-thread and PBackground thread
   // do not need anything special in order to be kept alive.
-  WorkerPrivate* workerPrivate = nullptr;
   if (!NS_IsMainThread()) {
-    workerPrivate = mozilla::dom::GetCurrentThreadWorkerPrivate();
+    mozilla::dom::WorkerPrivate* workerPrivate =
+      mozilla::dom::GetCurrentThreadWorkerPrivate();
     if (workerPrivate) {
-      bool result = HoldWorker(workerPrivate, WorkerStatus::Canceling);
-      if (!result) {
+      RefPtr<mozilla::dom::StrongWorkerRef> workerRef =
+        mozilla::dom::StrongWorkerRef::Create(workerPrivate, "IPCStreamSource");
+      if (NS_WARN_IF(!workerRef)) {
         return false;
       }
 
-      mWorkerPrivate = workerPrivate;
+      mWorkerRef = std::move(workerRef);
     } else {
       AssertIsOnBackgroundThread();
     }
@@ -161,15 +158,6 @@ IPCStreamSource::ActorConstructed()
   mState = eActorConstructed;
 }
 
-bool
-IPCStreamSource::Notify(WorkerStatus aStatus)
-{
-  NS_ASSERT_OWNINGTHREAD(IPCStreamSource);
-
-  // Keep the worker thread alive until the stream is finished.
-  return true;
-}
-
 void
 IPCStreamSource::ActorDestroyed()
 {
@@ -182,10 +170,7 @@ IPCStreamSource::ActorDestroyed()
     mCallback = nullptr;
   }
 
-  if (mWorkerPrivate) {
-    ReleaseWorker();
-    mWorkerPrivate = nullptr;
-  }
+  mWorkerRef = nullptr;
 }
 
 void
diff --git a/ipc/glue/IPCStreamSource.h b/ipc/glue/IPCStreamSource.h
index ef3fb6ab006d..8001af6508b1 100644
--- a/ipc/glue/IPCStreamSource.h
+++ b/ipc/glue/IPCStreamSource.h
@@ -8,8 +8,7 @@
 #define mozilla_ipc_IPCStreamSource_h
 
 #include "mozilla/AlreadyAddRefed.h"
-#include "mozilla/dom/WorkerHolder.h"
-#include "mozilla/dom/WorkerPrivate.h"
+#include "mozilla/dom/WorkerRef.h"
 
 class nsIAsyncInputStream;
 
@@ -56,7 +55,7 @@ class PParentToChildStreamParent;
 //
 // In general you should probably use the AutoIPCStreamSource RAII class
 // defined in InputStreamUtils.h instead of using IPCStreamSource directly.
-class IPCStreamSource : public dom::WorkerHolder
+class IPCStreamSource
 {
 public:
   // Create a IPCStreamSource using a PContent IPC manager on the
@@ -123,10 +122,6 @@ protected:
 private:
   class Callback;
 
-  // WorkerHolder methods
-  virtual bool
-  Notify(dom::WorkerStatus aStatus) override;
-
   void DoRead();
 
   void Wait();
@@ -136,10 +131,7 @@ private:
   nsCOMPtr<nsIAsyncInputStream> mStream;
   RefPtr<Callback> mCallback;
 
-  // Raw pointer because this IPCStreamSource keeps the worker alive using a
-  // WorkerHolder. The worker is kept alive when the actor is created and,
-  // released when the actor is destroyed.
-  dom::WorkerPrivate* mWorkerPrivate;
+  RefPtr<dom::StrongWorkerRef> mWorkerRef;
 
 #ifdef DEBUG
 protected: