import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

dom/cache/CacheChild.cpp

@@ -0,0 +1,185 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/cache/CacheChild.h"
+
+#include "mozilla/Unused.h"
+#include "mozilla/dom/cache/ActorUtils.h"
+#include "mozilla/dom/cache/Cache.h"
+#include "mozilla/dom/cache/CacheOpChild.h"
+
+namespace mozilla {
+namespace dom {
+namespace cache {
+
+// Declared in ActorUtils.h
+PCacheChild*
+AllocPCacheChild()
+{
+  return new CacheChild();
+}
+
+// Declared in ActorUtils.h
+void
+DeallocPCacheChild(PCacheChild* aActor)
+{
+  delete aActor;
+}
+
+CacheChild::CacheChild()
+  : mListener(nullptr)
+  , mNumChildActors(0)
+  , mDelayedDestroy(false)
+  , mLocked(false)
+{
+  MOZ_COUNT_CTOR(cache::CacheChild);
+}
+
+CacheChild::~CacheChild()
+{
+  MOZ_COUNT_DTOR(cache::CacheChild);
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  MOZ_DIAGNOSTIC_ASSERT(!mListener);
+  MOZ_DIAGNOSTIC_ASSERT(!mNumChildActors);
+  MOZ_DIAGNOSTIC_ASSERT(!mLocked);
+}
+
+void
+CacheChild::SetListener(Cache* aListener)
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  MOZ_DIAGNOSTIC_ASSERT(!mListener);
+  mListener = aListener;
+  MOZ_DIAGNOSTIC_ASSERT(mListener);
+}
+
+void
+CacheChild::ClearListener()
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  MOZ_DIAGNOSTIC_ASSERT(mListener);
+  mListener = nullptr;
+}
+
+void
+CacheChild::ExecuteOp(nsIGlobalObject* aGlobal, Promise* aPromise,
+                      nsISupports* aParent, const CacheOpArgs& aArgs)
+{
+  mNumChildActors += 1;
+  MOZ_ALWAYS_TRUE(SendPCacheOpConstructor(
+    new CacheOpChild(GetWorkerHolder(), aGlobal, aParent, aPromise), aArgs));
+}
+
+void
+CacheChild::StartDestroyFromListener()
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+
+  // The listener should be held alive by any async operations, so if it
+  // is going away then there must not be any child actors.  This in turn
+  // ensures that StartDestroy() will not trigger the delayed path.
+  MOZ_DIAGNOSTIC_ASSERT(!mNumChildActors);
+
+  StartDestroy();
+}
+
+void
+CacheChild::StartDestroy()
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+
+  // If we have outstanding child actors, then don't destroy ourself yet.
+  // The child actors should be short lived and we should allow them to complete
+  // if possible.  NoteDeletedActor() will call back into this Shutdown()
+  // method when the last child actor is gone.  Also, delay destruction if we
+  // have been explicitly locked by someone using us on the stack.
+  if (mNumChildActors || mLocked) {
+    mDelayedDestroy = true;
+    return;
+  }
+
+  RefPtr<Cache> listener = mListener;
+
+  // StartDestroy() can get called from either Cache or the WorkerHolder.
+  // Theoretically we can get double called if the right race happens.  Handle
+  // that by just ignoring the second StartDestroy() call.
+  if (!listener) {
+    return;
+  }
+
+  listener->DestroyInternal(this);
+
+  // Cache listener should call ClearListener() in DestroyInternal()
+  MOZ_DIAGNOSTIC_ASSERT(!mListener);
+
+  // Start actor destruction from parent process
+  Unused << SendTeardown();
+}
+
+void
+CacheChild::ActorDestroy(ActorDestroyReason aReason)
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  RefPtr<Cache> listener = mListener;
+  if (listener) {
+    listener->DestroyInternal(this);
+    // Cache listener should call ClearListener() in DestroyInternal()
+    MOZ_DIAGNOSTIC_ASSERT(!mListener);
+  }
+
+  RemoveWorkerHolder();
+}
+
+PCacheOpChild*
+CacheChild::AllocPCacheOpChild(const CacheOpArgs& aOpArgs)
+{
+  MOZ_CRASH("CacheOpChild should be manually constructed.");
+  return nullptr;
+}
+
+bool
+CacheChild::DeallocPCacheOpChild(PCacheOpChild* aActor)
+{
+  delete aActor;
+  NoteDeletedActor();
+  return true;
+}
+
+void
+CacheChild::NoteDeletedActor()
+{
+  mNumChildActors -= 1;
+  MaybeFlushDelayedDestroy();
+}
+
+void
+CacheChild::MaybeFlushDelayedDestroy()
+{
+  if (!mNumChildActors && !mLocked && mDelayedDestroy) {
+    StartDestroy();
+  }
+}
+
+void
+CacheChild::Lock()
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  MOZ_DIAGNOSTIC_ASSERT(!mLocked);
+  mLocked = true;
+}
+
+void
+CacheChild::Unlock()
+{
+  NS_ASSERT_OWNINGTHREAD(CacheChild);
+  MOZ_DIAGNOSTIC_ASSERT(mLocked);
+  mLocked = false;
+  MaybeFlushDelayedDestroy();
+}
+
+} // namespace cache
+} // namespace dom
+} // namespace mozilla