dom/cache/CacheStreamControlChild.cpp
author James Teh <jteh@mozilla.com>
Thu, 07 Mar 2019 18:10:13 +0000
changeset 520910 c26d4a8d43c4d0d6f6e13135b8f35924123fe99e
parent 507201 4e7923ac0159b263bfbe0b6922b485bb65005121
permissions -rw-r--r--
Bug 1527922: Ensure the Reload button is disabled when testing against blank tabs in the browser toolbar key nav tests. r=Gijs For a blank tab, the Reload button should be disabled. These tests depend on this. This seems to be true when setting the new tab page to blank in Firefox Options. However, when we open about:blank with BrowserTestUtils.withNewTab, this is unreliable. That is, sometimes the Reload button is enabled, sometimes it isn't. I don't understand why this happens. For the purposes of these tests, just force the Reload button to be disabled for new, blank tabs so we get consistent results. Differential Revision: https://phabricator.services.mozilla.com/D22449

/* -*- 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/CacheStreamControlChild.h"

#include "mozilla/Unused.h"
#include "mozilla/dom/cache/ActorUtils.h"
#include "mozilla/dom/cache/CacheTypes.h"
#include "mozilla/dom/cache/CacheWorkerHolder.h"
#include "mozilla/dom/cache/ReadStream.h"
#include "mozilla/ipc/FileDescriptorSetChild.h"
#include "mozilla/ipc/IPCStreamUtils.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/ipc/PFileDescriptorSetChild.h"
#include "nsISupportsImpl.h"

namespace mozilla {
namespace dom {
namespace cache {

using mozilla::dom::OptionalFileDescriptorSet;
using mozilla::ipc::AutoIPCStream;
using mozilla::ipc::FileDescriptor;
using mozilla::ipc::FileDescriptorSetChild;
using mozilla::ipc::PFileDescriptorSetChild;

// declared in ActorUtils.h
PCacheStreamControlChild* AllocPCacheStreamControlChild() {
  return new CacheStreamControlChild();
}

// declared in ActorUtils.h
void DeallocPCacheStreamControlChild(PCacheStreamControlChild* aActor) {
  delete aActor;
}

CacheStreamControlChild::CacheStreamControlChild()
    : mDestroyStarted(false), mDestroyDelayed(false) {
  MOZ_COUNT_CTOR(cache::CacheStreamControlChild);
}

CacheStreamControlChild::~CacheStreamControlChild() {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  MOZ_COUNT_DTOR(cache::CacheStreamControlChild);
}

void CacheStreamControlChild::StartDestroy() {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  // This can get called twice under some circumstances.  For example, if the
  // actor is added to a CacheWorkerHolder that has already been notified and
  // the Cache actor has no mListener.
  if (mDestroyStarted) {
    return;
  }
  mDestroyStarted = true;

  // If any of the streams have started to be read, then wait for them to close
  // naturally.
  if (HasEverBeenRead()) {
    // Note that we are delaying so that we can re-check for active streams
    // in NoteClosedAfterForget().
    mDestroyDelayed = true;
    return;
  }

  // Otherwise, if the streams have not been touched then just pre-emptively
  // close them now.  This handles the case where someone retrieves a Response
  // from the Cache, but never accesses the body.  We should not keep the
  // Worker alive until that Response is GC'd just because of its ignored
  // body stream.

  // Begin shutting down all streams.  This is the same as if the parent had
  // asked us to shutdown.  So simulate the CloseAll IPC message.
  RecvCloseAll();
}

void CacheStreamControlChild::SerializeControl(
    CacheReadStream* aReadStreamOut) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
  aReadStreamOut->controlParent() = nullptr;
  aReadStreamOut->controlChild() = this;
}

void CacheStreamControlChild::SerializeStream(
    CacheReadStream* aReadStreamOut, nsIInputStream* aStream,
    nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
  UniquePtr<AutoIPCStream> autoStream(
      new AutoIPCStream(aReadStreamOut->stream()));
  autoStream->Serialize(aStream, Manager());
  aStreamCleanupList.AppendElement(std::move(autoStream));
}

void CacheStreamControlChild::OpenStream(const nsID& aId,
                                         InputStreamResolver&& aResolver) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);

  if (mDestroyStarted) {
    aResolver(nullptr);
    return;
  }

  // If we are on a worker, then we need to hold it alive until the async
  // IPC operation below completes.  While the IPC layer will trigger a
  // rejection here in many cases, we must handle the case where the
  // MozPromise resolve runnable is already in the event queue when the
  // worker wants to shut down.
  RefPtr<CacheWorkerHolder> holder = GetWorkerHolder();

  SendOpenStream(aId)->Then(
      GetCurrentThreadSerialEventTarget(), __func__,
      [aResolver, holder](RefPtr<nsIInputStream>&& aOptionalStream) {
        aResolver(nsCOMPtr<nsIInputStream>(aOptionalStream.forget()));
      },
      [aResolver, holder](ResponseRejectReason&& aReason) {
        aResolver(nullptr);
      });
}

void CacheStreamControlChild::NoteClosedAfterForget(const nsID& aId) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  Unused << SendNoteClosed(aId);

  // A stream has closed.  If we delayed StartDestry() due to this stream
  // being read, then we should check to see if any of the remaining streams
  // are active.  If none of our other streams have been read, then we can
  // proceed with the shutdown now.
  if (mDestroyDelayed && !HasEverBeenRead()) {
    mDestroyDelayed = false;
    RecvCloseAll();
  }
}

#ifdef DEBUG
void CacheStreamControlChild::AssertOwningThread() {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
}
#endif

void CacheStreamControlChild::ActorDestroy(ActorDestroyReason aReason) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  CloseAllReadStreamsWithoutReporting();
  RemoveWorkerHolder();
}

mozilla::ipc::IPCResult CacheStreamControlChild::RecvClose(const nsID& aId) {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  CloseReadStreams(aId);
  return IPC_OK();
}

mozilla::ipc::IPCResult CacheStreamControlChild::RecvCloseAll() {
  NS_ASSERT_OWNINGTHREAD(CacheStreamControlChild);
  CloseAllReadStreams();
  return IPC_OK();
}

}  // namespace cache
}  // namespace dom
}  // namespace mozilla