tenfourfox/dom/cache/CacheChild.cpp

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2017-04-19 07:56:45 +00:00
/* -*- 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 "mozilla/dom/cache/CachePushStreamChild.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_ASSERT(!mListener);
MOZ_ASSERT(!mNumChildActors);
MOZ_ASSERT(!mLocked);
}
void
CacheChild::SetListener(Cache* aListener)
{
NS_ASSERT_OWNINGTHREAD(CacheChild);
MOZ_ASSERT(!mListener);
mListener = aListener;
MOZ_ASSERT(mListener);
}
void
CacheChild::ClearListener()
{
NS_ASSERT_OWNINGTHREAD(CacheChild);
MOZ_ASSERT(mListener);
mListener = nullptr;
}
void
CacheChild::ExecuteOp(nsIGlobalObject* aGlobal, Promise* aPromise,
nsISupports* aParent, const CacheOpArgs& aArgs)
{
mNumChildActors += 1;
MOZ_ALWAYS_TRUE(SendPCacheOpConstructor(
new CacheOpChild(GetFeature(), aGlobal, aParent, aPromise), aArgs));
}
CachePushStreamChild*
CacheChild::CreatePushStream(nsISupports* aParent, nsIAsyncInputStream* aStream)
{
mNumChildActors += 1;
auto actor = SendPCachePushStreamConstructor(
new CachePushStreamChild(GetFeature(), aParent, aStream));
MOZ_ASSERT(actor);
return static_cast<CachePushStreamChild*>(actor);
}
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_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 Feature.
// 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_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_ASSERT(!mListener);
}
RemoveFeature();
}
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;
}
PCachePushStreamChild*
CacheChild::AllocPCachePushStreamChild()
{
MOZ_CRASH("CachePushStreamChild should be manually constructed.");
return nullptr;
}
bool
CacheChild::DeallocPCachePushStreamChild(PCachePushStreamChild* 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_ASSERT(!mLocked);
mLocked = true;
}
void
CacheChild::Unlock()
{
NS_ASSERT_OWNINGTHREAD(CacheChild);
MOZ_ASSERT(mLocked);
mLocked = false;
MaybeFlushDelayedDestroy();
}
} // namespace cache
} // namespace dom
} // namespace mozilla