1 files changed, 150 insertions, 0 deletions
diff --git a/dom/cache/CacheChild.cpp b/dom/cache/CacheChild.cpp
new file mode 100644
index 0000000000..14c0bf8607
--- /dev/null
+++ b/dom/cache/CacheChild.cpp
@@ -0,0 +1,150 @@
+/* -*- 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"
+#include "CacheWorkerRef.h"
+
+namespace mozilla::dom::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(GetWorkerRefPtr().clonePtr(),
+                                               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 WorkerRef.
+  // 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);
+  }
+
+  RemoveWorkerRef();
+}
+
+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 mozilla::dom::cache