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gecko-dev/dom/cache/Context.cpp

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/* -*- 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/Context.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/dom/cache/Action.h"
#include "mozilla/dom/cache/FileUtils.h"
#include "mozilla/dom/cache/Manager.h"
#include "mozilla/dom/cache/ManagerId.h"
#include "mozilla/dom/quota/QuotaManager.h"
#include "mozIStorageConnection.h"
#include "nsIFile.h"
#include "nsIPrincipal.h"
#include "nsIRunnable.h"
#include "nsThreadUtils.h"
namespace {
using mozilla::dom::cache::Action;
using mozilla::dom::cache::QuotaInfo;
class NullAction final : public Action
{
public:
NullAction()
{
}
virtual void
RunOnTarget(Resolver* aResolver, const QuotaInfo&, Data*) override
{
// Resolve success immediately. This Action does no actual work.
MOZ_ASSERT(aResolver);
aResolver->Resolve(NS_OK);
}
};
} // namespace
namespace mozilla {
namespace dom {
namespace cache {
using mozilla::DebugOnly;
using mozilla::dom::quota::AssertIsOnIOThread;
using mozilla::dom::quota::OpenDirectoryListener;
using mozilla::dom::quota::QuotaManager;
using mozilla::dom::quota::PERSISTENCE_TYPE_DEFAULT;
using mozilla::dom::quota::PersistenceType;
class Context::Data final : public Action::Data
{
public:
explicit Data(nsIThread* aTarget)
: mTarget(aTarget)
{
MOZ_ASSERT(mTarget);
}
virtual mozIStorageConnection*
GetConnection() const override
{
MOZ_ASSERT(mTarget == NS_GetCurrentThread());
return mConnection;
}
virtual void
SetConnection(mozIStorageConnection* aConn) override
{
MOZ_ASSERT(mTarget == NS_GetCurrentThread());
MOZ_ASSERT(!mConnection);
mConnection = aConn;
MOZ_ASSERT(mConnection);
}
private:
~Data()
{
// We could proxy release our data here, but instead just assert. The
// Context code should guarantee that we are destroyed on the target
// thread once the connection is initialized. If we're not, then
// QuotaManager might race and try to clear the origin out from under us.
MOZ_ASSERT_IF(mConnection, mTarget == NS_GetCurrentThread());
}
nsCOMPtr<nsIThread> mTarget;
nsCOMPtr<mozIStorageConnection> mConnection;
// Threadsafe counting because we're created on the PBackground thread
// and destroyed on the target IO thread.
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(Context::Data)
};
// Executed to perform the complicated dance of steps necessary to initialize
// the QuotaManager. This must be performed for each origin before any disk
// IO occurrs.
class Context::QuotaInitRunnable final : public nsIRunnable
, public OpenDirectoryListener
{
public:
QuotaInitRunnable(Context* aContext,
Manager* aManager,
Data* aData,
nsIThread* aTarget,
Action* aInitAction)
: mContext(aContext)
, mThreadsafeHandle(aContext->CreateThreadsafeHandle())
, mManager(aManager)
, mData(aData)
, mTarget(aTarget)
, mInitAction(aInitAction)
, mInitiatingThread(NS_GetCurrentThread())
, mResult(NS_OK)
, mState(STATE_INIT)
, mCanceled(false)
{
MOZ_ASSERT(mContext);
MOZ_ASSERT(mManager);
MOZ_ASSERT(mData);
MOZ_ASSERT(mTarget);
MOZ_ASSERT(mInitiatingThread);
MOZ_ASSERT(mInitAction);
}
nsresult Dispatch()
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(mState == STATE_INIT);
mState = STATE_GET_INFO;
nsresult rv = NS_DispatchToMainThread(this, nsIThread::DISPATCH_NORMAL);
if (NS_WARN_IF(NS_FAILED(rv))) {
mState = STATE_COMPLETE;
Clear();
}
return rv;
}
void Cancel()
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(!mCanceled);
mCanceled = true;
mInitAction->CancelOnInitiatingThread();
}
void OpenDirectory();
// OpenDirectoryListener methods
virtual void
DirectoryLockAcquired(DirectoryLock* aLock) override;
virtual void
DirectoryLockFailed() override;
private:
class SyncResolver final : public Action::Resolver
{
public:
SyncResolver()
: mResolved(false)
, mResult(NS_OK)
{ }
virtual void
Resolve(nsresult aRv) override
{
MOZ_ASSERT(!mResolved);
mResolved = true;
mResult = aRv;
};
bool Resolved() const { return mResolved; }
nsresult Result() const { return mResult; }
private:
~SyncResolver() { }
bool mResolved;
nsresult mResult;
NS_INLINE_DECL_REFCOUNTING(Context::QuotaInitRunnable::SyncResolver, override)
};
~QuotaInitRunnable()
{
MOZ_ASSERT(mState == STATE_COMPLETE);
MOZ_ASSERT(!mContext);
MOZ_ASSERT(!mInitAction);
}
enum State
{
STATE_INIT,
STATE_GET_INFO,
STATE_CREATE_QUOTA_MANAGER,
STATE_OPEN_DIRECTORY,
STATE_WAIT_FOR_DIRECTORY_LOCK,
STATE_ENSURE_ORIGIN_INITIALIZED,
STATE_RUN_ON_TARGET,
STATE_RUNNING,
STATE_COMPLETING,
STATE_COMPLETE
};
void Complete(nsresult aResult)
{
MOZ_ASSERT(mState == STATE_RUNNING || NS_FAILED(aResult));
MOZ_ASSERT(NS_SUCCEEDED(mResult));
mResult = aResult;
mState = STATE_COMPLETING;
MOZ_ALWAYS_SUCCEEDS(
mInitiatingThread->Dispatch(this, nsIThread::DISPATCH_NORMAL));
}
void Clear()
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(mContext);
mContext = nullptr;
mManager = nullptr;
mInitAction = nullptr;
}
RefPtr<Context> mContext;
RefPtr<ThreadsafeHandle> mThreadsafeHandle;
RefPtr<Manager> mManager;
RefPtr<Data> mData;
nsCOMPtr<nsIThread> mTarget;
RefPtr<Action> mInitAction;
nsCOMPtr<nsIThread> mInitiatingThread;
nsresult mResult;
QuotaInfo mQuotaInfo;
RefPtr<DirectoryLock> mDirectoryLock;
State mState;
Atomic<bool> mCanceled;
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
};
void
Context::QuotaInitRunnable::OpenDirectory()
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(mState == STATE_CREATE_QUOTA_MANAGER ||
mState == STATE_OPEN_DIRECTORY);
MOZ_ASSERT(QuotaManager::Get());
// QuotaManager::OpenDirectory() will hold a reference to us as
// a listener. We will then get DirectoryLockAcquired() on the owning
// thread when it is safe to access our storage directory.
mState = STATE_WAIT_FOR_DIRECTORY_LOCK;
QuotaManager::Get()->OpenDirectory(PERSISTENCE_TYPE_DEFAULT,
mQuotaInfo.mGroup,
mQuotaInfo.mOrigin,
mQuotaInfo.mIsApp,
quota::Client::DOMCACHE,
/* aExclusive */ false,
this);
}
void
Context::QuotaInitRunnable::DirectoryLockAcquired(DirectoryLock* aLock)
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(mState == STATE_WAIT_FOR_DIRECTORY_LOCK);
MOZ_ASSERT(!mDirectoryLock);
mDirectoryLock = aLock;
if (mCanceled) {
Complete(NS_ERROR_ABORT);
return;
}
QuotaManager* qm = QuotaManager::Get();
MOZ_ASSERT(qm);
mState = STATE_ENSURE_ORIGIN_INITIALIZED;
nsresult rv = qm->IOThread()->Dispatch(this, nsIThread::DISPATCH_NORMAL);
if (NS_WARN_IF(NS_FAILED(rv))) {
Complete(rv);
return;
}
}
void
Context::QuotaInitRunnable::DirectoryLockFailed()
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
MOZ_ASSERT(mState == STATE_WAIT_FOR_DIRECTORY_LOCK);
MOZ_ASSERT(!mDirectoryLock);
NS_WARNING("Failed to acquire a directory lock!");
Complete(NS_ERROR_FAILURE);
}
NS_IMPL_ISUPPORTS(mozilla::dom::cache::Context::QuotaInitRunnable, nsIRunnable);
// The QuotaManager init state machine is represented in the following diagram:
//
// +---------------+
// | Start | Resolve(error)
// | (Orig Thread) +---------------------+
// +-------+-------+ |
// | |
// +----------v-----------+ |
// | GetInfo | Resolve(error) |
// | (Main Thread) +-----------------+
// +----------+-----------+ |
// | |
// +----------v-----------+ |
// | CreateQuotaManager | Resolve(error) |
// | (Orig Thread) +-----------------+
// +----------+-----------+ |
// | |
// +----------v-----------+ |
// | OpenDirectory | Resolve(error) |
// | (Orig Thread) +-----------------+
// +----------+-----------+ |
// | |
// +----------v-----------+ |
// | WaitForDirectoryLock | Resolve(error) |
// | (Orig Thread) +-----------------+
// +----------+-----------+ |
// | |
// +----------v------------+ |
// |EnsureOriginInitialized| Resolve(error) |
// | (Quota IO Thread) +----------------+
// +----------+------------+ |
// | |
// +----------v------------+ |
// | RunOnTarget | Resolve(error) |
// | (Target Thread) +----------------+
// +----------+------------+ |
// | |
// +---------v---------+ +------v------+
// | Running | | Completing |
// | (Target Thread) +------------>(Orig Thread)|
// +-------------------+ +------+------+
// |
// +-----v----+
// | Complete |
// +----------+
//
// The initialization process proceeds through the main states. If an error
// occurs, then we transition to Completing state back on the original thread.
NS_IMETHODIMP
Context::QuotaInitRunnable::Run()
{
// May run on different threads depending on the state. See individual
// state cases for thread assertions.
RefPtr<SyncResolver> resolver = new SyncResolver();
switch(mState) {
// -----------------------------------
case STATE_GET_INFO:
{
MOZ_ASSERT(NS_IsMainThread());
if (mCanceled) {
resolver->Resolve(NS_ERROR_ABORT);
break;
}
RefPtr<ManagerId> managerId = mManager->GetManagerId();
nsCOMPtr<nsIPrincipal> principal = managerId->Principal();
nsresult rv = QuotaManager::GetInfoFromPrincipal(principal,
&mQuotaInfo.mSuffix,
&mQuotaInfo.mGroup,
&mQuotaInfo.mOrigin,
&mQuotaInfo.mIsApp);
if (NS_WARN_IF(NS_FAILED(rv))) {
resolver->Resolve(rv);
break;
}
mState = STATE_CREATE_QUOTA_MANAGER;
MOZ_ALWAYS_SUCCEEDS(
mInitiatingThread->Dispatch(this, nsIThread::DISPATCH_NORMAL));
break;
}
// ----------------------------------
case STATE_CREATE_QUOTA_MANAGER:
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
if (mCanceled || QuotaManager::IsShuttingDown()) {
resolver->Resolve(NS_ERROR_ABORT);
break;
}
if (QuotaManager::Get()) {
OpenDirectory();
return NS_OK;
}
mState = STATE_OPEN_DIRECTORY;
QuotaManager::GetOrCreate(this);
break;
}
// ----------------------------------
case STATE_OPEN_DIRECTORY:
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
if (NS_WARN_IF(!QuotaManager::Get())) {
resolver->Resolve(NS_ERROR_FAILURE);
break;
}
OpenDirectory();
break;
}
// ----------------------------------
case STATE_ENSURE_ORIGIN_INITIALIZED:
{
AssertIsOnIOThread();
if (mCanceled) {
resolver->Resolve(NS_ERROR_ABORT);
break;
}
QuotaManager* qm = QuotaManager::Get();
MOZ_ASSERT(qm);
nsresult rv = qm->EnsureOriginIsInitialized(PERSISTENCE_TYPE_DEFAULT,
mQuotaInfo.mSuffix,
mQuotaInfo.mGroup,
mQuotaInfo.mOrigin,
mQuotaInfo.mIsApp,
getter_AddRefs(mQuotaInfo.mDir));
if (NS_FAILED(rv)) {
resolver->Resolve(rv);
break;
}
mState = STATE_RUN_ON_TARGET;
MOZ_ALWAYS_SUCCEEDS(
mTarget->Dispatch(this, nsIThread::DISPATCH_NORMAL));
break;
}
// -------------------
case STATE_RUN_ON_TARGET:
{
MOZ_ASSERT(NS_GetCurrentThread() == mTarget);
mState = STATE_RUNNING;
// Execute the provided initialization Action. The Action must Resolve()
// before returning.
mInitAction->RunOnTarget(resolver, mQuotaInfo, mData);
MOZ_ASSERT(resolver->Resolved());
mData = nullptr;
// If the database was opened, then we should always succeed when creating
// the marker file. If it wasn't opened successfully, then no need to
// create a marker file anyway.
if (NS_SUCCEEDED(resolver->Result())) {
MOZ_ALWAYS_SUCCEEDS(CreateMarkerFile(mQuotaInfo));
}
break;
}
// -------------------
case STATE_COMPLETING:
{
NS_ASSERT_OWNINGTHREAD(QuotaInitRunnable);
mInitAction->CompleteOnInitiatingThread(mResult);
mContext->OnQuotaInit(mResult, mQuotaInfo, mDirectoryLock.forget());
mState = STATE_COMPLETE;
// Explicitly cleanup here as the destructor could fire on any of
// the threads we have bounced through.
Clear();
break;
}
// -----
case STATE_WAIT_FOR_DIRECTORY_LOCK:
default:
{
MOZ_CRASH("unexpected state in QuotaInitRunnable");
}
}
if (resolver->Resolved()) {
Complete(resolver->Result());
}
return NS_OK;
}
// Runnable wrapper around Action objects dispatched on the Context. This
// runnable executes the Action on the appropriate threads while the Context
// is initialized.
class Context::ActionRunnable final : public nsIRunnable
, public Action::Resolver
, public Context::Activity
{
public:
ActionRunnable(Context* aContext, Data* aData, nsIEventTarget* aTarget,
Action* aAction, const QuotaInfo& aQuotaInfo)
: mContext(aContext)
, mData(aData)
, mTarget(aTarget)
, mAction(aAction)
, mQuotaInfo(aQuotaInfo)
, mInitiatingThread(NS_GetCurrentThread())
, mState(STATE_INIT)
, mResult(NS_OK)
, mExecutingRunOnTarget(false)
{
MOZ_ASSERT(mContext);
// mData may be nullptr
MOZ_ASSERT(mTarget);
MOZ_ASSERT(mAction);
// mQuotaInfo.mDir may be nullptr if QuotaInitRunnable failed
MOZ_ASSERT(mInitiatingThread);
}
nsresult Dispatch()
{
NS_ASSERT_OWNINGTHREAD(ActionRunnable);
MOZ_ASSERT(mState == STATE_INIT);
mState = STATE_RUN_ON_TARGET;
nsresult rv = mTarget->Dispatch(this, nsIEventTarget::DISPATCH_NORMAL);
if (NS_WARN_IF(NS_FAILED(rv))) {
mState = STATE_COMPLETE;
Clear();
}
return rv;
}
virtual bool
MatchesCacheId(CacheId aCacheId) const override
{
NS_ASSERT_OWNINGTHREAD(ActionRunnable);
return mAction->MatchesCacheId(aCacheId);
}
virtual void
Cancel() override
{
NS_ASSERT_OWNINGTHREAD(ActionRunnable);
mAction->CancelOnInitiatingThread();
}
virtual void Resolve(nsresult aRv) override
{
MOZ_ASSERT(mTarget == NS_GetCurrentThread());
MOZ_ASSERT(mState == STATE_RUNNING);
mResult = aRv;
// We ultimately must complete on the initiating thread, but bounce through
// the current thread again to ensure that we don't destroy objects and
// state out from under the currently running action's stack.
mState = STATE_RESOLVING;
// If we were resolved synchronously within Action::RunOnTarget() then we
// can avoid a thread bounce and just resolve once RunOnTarget() returns.
// The Run() method will handle this by looking at mState after
// RunOnTarget() returns.
if (mExecutingRunOnTarget) {
return;
}
// Otherwise we are in an asynchronous resolve. And must perform a thread
// bounce to run on the target thread again.
MOZ_ALWAYS_SUCCEEDS(
mTarget->Dispatch(this, nsIThread::DISPATCH_NORMAL));
}
private:
~ActionRunnable()
{
MOZ_ASSERT(mState == STATE_COMPLETE);
MOZ_ASSERT(!mContext);
MOZ_ASSERT(!mAction);
}
void Clear()
{
NS_ASSERT_OWNINGTHREAD(ActionRunnable);
MOZ_ASSERT(mContext);
MOZ_ASSERT(mAction);
mContext->RemoveActivity(this);
mContext = nullptr;
mAction = nullptr;
}
enum State
{
STATE_INIT,
STATE_RUN_ON_TARGET,
STATE_RUNNING,
STATE_RESOLVING,
STATE_COMPLETING,
STATE_COMPLETE
};
RefPtr<Context> mContext;
RefPtr<Data> mData;
nsCOMPtr<nsIEventTarget> mTarget;
RefPtr<Action> mAction;
const QuotaInfo mQuotaInfo;
nsCOMPtr<nsIThread> mInitiatingThread;
State mState;
nsresult mResult;
// Only accessible on target thread;
bool mExecutingRunOnTarget;
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIRUNNABLE
};
NS_IMPL_ISUPPORTS(mozilla::dom::cache::Context::ActionRunnable, nsIRunnable);
// The ActionRunnable has a simpler state machine. It basically needs to run
// the action on the target thread and then complete on the original thread.
//
// +-------------+
// | Start |
// |(Orig Thread)|
// +-----+-------+
// |
// +-------v---------+
// | RunOnTarget |
// |Target IO Thread)+---+ Resolve()
// +-------+---------+ |
// | |
// +-------v----------+ |
// | Running | |
// |(Target IO Thread)| |
// +------------------+ |
// | Resolve() |
// +-------v----------+ |
// | Resolving <--+ +-------------+
// | | | Completing |
// |(Target IO Thread)+---------------------->(Orig Thread)|
// +------------------+ +-------+-----+
// |
// |
// +----v---+
// |Complete|
// +--------+
//
// Its important to note that synchronous actions will effectively Resolve()
// out of the Running state immediately. Asynchronous Actions may remain
// in the Running state for some time, but normally the ActionRunnable itself
// does not see any execution there. Its all handled internal to the Action.
NS_IMETHODIMP
Context::ActionRunnable::Run()
{
switch(mState) {
// ----------------------
case STATE_RUN_ON_TARGET:
{
MOZ_ASSERT(NS_GetCurrentThread() == mTarget);
MOZ_ASSERT(!mExecutingRunOnTarget);
// Note that we are calling RunOnTarget(). This lets us detect
// if Resolve() is called synchronously.
AutoRestore<bool> executingRunOnTarget(mExecutingRunOnTarget);
mExecutingRunOnTarget = true;
mState = STATE_RUNNING;
mAction->RunOnTarget(this, mQuotaInfo, mData);
mData = nullptr;
// Resolve was called synchronously from RunOnTarget(). We can
// immediately move to completing now since we are sure RunOnTarget()
// completed.
if (mState == STATE_RESOLVING) {
// Use recursion instead of switch case fall-through... Seems slightly
// easier to understand.
Run();
}
break;
}
// -----------------
case STATE_RESOLVING:
{
MOZ_ASSERT(NS_GetCurrentThread() == mTarget);
// The call to Action::RunOnTarget() must have returned now if we
// are running on the target thread again. We may now proceed
// with completion.
mState = STATE_COMPLETING;
// Shutdown must be delayed until all Contexts are destroyed. Crash
// for this invariant violation.
MOZ_ALWAYS_SUCCEEDS(
mInitiatingThread->Dispatch(this, nsIThread::DISPATCH_NORMAL));
break;
}
// -------------------
case STATE_COMPLETING:
{
NS_ASSERT_OWNINGTHREAD(ActionRunnable);
mAction->CompleteOnInitiatingThread(mResult);
mState = STATE_COMPLETE;
// Explicitly cleanup here as the destructor could fire on any of
// the threads we have bounced through.
Clear();
break;
}
// -----------------
default:
{
MOZ_CRASH("unexpected state in ActionRunnable");
break;
}
}
return NS_OK;
}
void
Context::ThreadsafeHandle::AllowToClose()
{
if (mOwningThread == NS_GetCurrentThread()) {
AllowToCloseOnOwningThread();
return;
}
// Dispatch is guaranteed to succeed here because we block shutdown until
// all Contexts have been destroyed.
nsCOMPtr<nsIRunnable> runnable =
NewRunnableMethod(this, &ThreadsafeHandle::AllowToCloseOnOwningThread);
MOZ_ALWAYS_SUCCEEDS(
mOwningThread->Dispatch(runnable, nsIThread::DISPATCH_NORMAL));
}
void
Context::ThreadsafeHandle::InvalidateAndAllowToClose()
{
if (mOwningThread == NS_GetCurrentThread()) {
InvalidateAndAllowToCloseOnOwningThread();
return;
}
// Dispatch is guaranteed to succeed here because we block shutdown until
// all Contexts have been destroyed.
nsCOMPtr<nsIRunnable> runnable =
NewRunnableMethod(this, &ThreadsafeHandle::InvalidateAndAllowToCloseOnOwningThread);
MOZ_ALWAYS_SUCCEEDS(
mOwningThread->Dispatch(runnable, nsIThread::DISPATCH_NORMAL));
}
Context::ThreadsafeHandle::ThreadsafeHandle(Context* aContext)
: mStrongRef(aContext)
, mWeakRef(aContext)
, mOwningThread(NS_GetCurrentThread())
{
}
Context::ThreadsafeHandle::~ThreadsafeHandle()
{
// Normally we only touch mStrongRef on the owning thread. This is safe,
// however, because when we do use mStrongRef on the owning thread we are
// always holding a strong ref to the ThreadsafeHandle via the owning
// runnable. So we cannot run the ThreadsafeHandle destructor simultaneously.
if (!mStrongRef || mOwningThread == NS_GetCurrentThread()) {
return;
}
// Dispatch is guaranteed to succeed here because we block shutdown until
// all Contexts have been destroyed.
NS_ProxyRelease(mOwningThread, mStrongRef.forget());
}
void
Context::ThreadsafeHandle::AllowToCloseOnOwningThread()
{
MOZ_ASSERT(mOwningThread == NS_GetCurrentThread());
// A Context "closes" when its ref count drops to zero. Dropping this
// strong ref is necessary, but not sufficient for the close to occur.
// Any outstanding IO will continue and keep the Context alive. Once
// the Context is idle, it will be destroyed.
// First, tell the context to flush any target thread shared data. This
// data must be released on the target thread prior to running the Context
// destructor. This will schedule an Action which ensures that the
// ~Context() is not immediately executed when we drop the strong ref.
if (mStrongRef) {
mStrongRef->DoomTargetData();
}
// Now drop our strong ref and let Context finish running any outstanding
// Actions.
mStrongRef = nullptr;
}
void
Context::ThreadsafeHandle::InvalidateAndAllowToCloseOnOwningThread()
{
MOZ_ASSERT(mOwningThread == NS_GetCurrentThread());
// Cancel the Context through the weak reference. This means we can
// allow the Context to close by dropping the strong ref, but then
// still cancel ongoing IO if necessary.
if (mWeakRef) {
mWeakRef->Invalidate();
}
// We should synchronously have AllowToCloseOnOwningThread called when
// the Context is canceled.
MOZ_ASSERT(!mStrongRef);
}
void
Context::ThreadsafeHandle::ContextDestroyed(Context* aContext)
{
MOZ_ASSERT(mOwningThread == NS_GetCurrentThread());
MOZ_ASSERT(!mStrongRef);
MOZ_ASSERT(mWeakRef);
MOZ_ASSERT(mWeakRef == aContext);
mWeakRef = nullptr;
}
// static
already_AddRefed<Context>
Context::Create(Manager* aManager, nsIThread* aTarget,
Action* aInitAction, Context* aOldContext)
{
RefPtr<Context> context = new Context(aManager, aTarget, aInitAction);
context->Init(aOldContext);
return context.forget();
}
Context::Context(Manager* aManager, nsIThread* aTarget, Action* aInitAction)
: mManager(aManager)
, mTarget(aTarget)
, mData(new Data(aTarget))
, mState(STATE_CONTEXT_PREINIT)
, mOrphanedData(false)
, mInitAction(aInitAction)
{
MOZ_ASSERT(mManager);
MOZ_ASSERT(mTarget);
}
void
Context::Dispatch(Action* aAction)
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(aAction);
MOZ_ASSERT(mState != STATE_CONTEXT_CANCELED);
if (mState == STATE_CONTEXT_CANCELED) {
return;
} else if (mState == STATE_CONTEXT_INIT ||
mState == STATE_CONTEXT_PREINIT) {
PendingAction* pending = mPendingActions.AppendElement();
pending->mAction = aAction;
return;
}
MOZ_ASSERT(STATE_CONTEXT_READY);
DispatchAction(aAction);
}
void
Context::CancelAll()
{
NS_ASSERT_OWNINGTHREAD(Context);
// In PREINIT state we have not dispatch the init action yet. Just
// forget it.
if (mState == STATE_CONTEXT_PREINIT) {
MOZ_ASSERT(!mInitRunnable);
mInitAction = nullptr;
// In INIT state we have dispatched the runnable, but not received the
// async completion yet. Cancel the runnable, but don't forget about it
// until we get OnQuotaInit() callback.
} else if (mState == STATE_CONTEXT_INIT) {
mInitRunnable->Cancel();
}
mState = STATE_CONTEXT_CANCELED;
mPendingActions.Clear();
{
ActivityList::ForwardIterator iter(mActivityList);
while (iter.HasMore()) {
iter.GetNext()->Cancel();
}
}
AllowToClose();
}
bool
Context::IsCanceled() const
{
NS_ASSERT_OWNINGTHREAD(Context);
return mState == STATE_CONTEXT_CANCELED;
}
void
Context::Invalidate()
{
NS_ASSERT_OWNINGTHREAD(Context);
mManager->NoteClosing();
CancelAll();
}
void
Context::AllowToClose()
{
NS_ASSERT_OWNINGTHREAD(Context);
if (mThreadsafeHandle) {
mThreadsafeHandle->AllowToClose();
}
}
void
Context::CancelForCacheId(CacheId aCacheId)
{
NS_ASSERT_OWNINGTHREAD(Context);
// Remove matching pending actions
for (int32_t i = mPendingActions.Length() - 1; i >= 0; --i) {
if (mPendingActions[i].mAction->MatchesCacheId(aCacheId)) {
mPendingActions.RemoveElementAt(i);
}
}
// Cancel activities and let them remove themselves
ActivityList::ForwardIterator iter(mActivityList);
while (iter.HasMore()) {
Activity* activity = iter.GetNext();
if (activity->MatchesCacheId(aCacheId)) {
activity->Cancel();
}
}
}
Context::~Context()
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(mManager);
MOZ_ASSERT(!mData);
if (mThreadsafeHandle) {
mThreadsafeHandle->ContextDestroyed(this);
}
// Note, this may set the mOrphanedData flag.
mManager->RemoveContext(this);
if (mQuotaInfo.mDir && !mOrphanedData) {
MOZ_ALWAYS_SUCCEEDS(DeleteMarkerFile(mQuotaInfo));
}
if (mNextContext) {
mNextContext->Start();
}
}
void
Context::Init(Context* aOldContext)
{
NS_ASSERT_OWNINGTHREAD(Context);
if (aOldContext) {
aOldContext->SetNextContext(this);
return;
}
Start();
}
void
Context::Start()
{
NS_ASSERT_OWNINGTHREAD(Context);
// Previous context closing delayed our start, but then we were canceled.
// In this case, just do nothing here.
if (mState == STATE_CONTEXT_CANCELED) {
MOZ_ASSERT(!mInitRunnable);
MOZ_ASSERT(!mInitAction);
return;
}
MOZ_ASSERT(mState == STATE_CONTEXT_PREINIT);
MOZ_ASSERT(!mInitRunnable);
mInitRunnable = new QuotaInitRunnable(this, mManager, mData, mTarget,
mInitAction);
mInitAction = nullptr;
mState = STATE_CONTEXT_INIT;
nsresult rv = mInitRunnable->Dispatch();
if (NS_FAILED(rv)) {
// Shutdown must be delayed until all Contexts are destroyed. Shutdown
// must also prevent any new Contexts from being constructed. Crash
// for this invariant violation.
MOZ_CRASH("Failed to dispatch QuotaInitRunnable.");
}
}
void
Context::DispatchAction(Action* aAction, bool aDoomData)
{
NS_ASSERT_OWNINGTHREAD(Context);
RefPtr<ActionRunnable> runnable =
new ActionRunnable(this, mData, mTarget, aAction, mQuotaInfo);
if (aDoomData) {
mData = nullptr;
}
nsresult rv = runnable->Dispatch();
if (NS_FAILED(rv)) {
// Shutdown must be delayed until all Contexts are destroyed. Crash
// for this invariant violation.
MOZ_CRASH("Failed to dispatch ActionRunnable to target thread.");
}
AddActivity(runnable);
}
void
Context::OnQuotaInit(nsresult aRv, const QuotaInfo& aQuotaInfo,
already_AddRefed<DirectoryLock> aDirectoryLock)
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(mInitRunnable);
mInitRunnable = nullptr;
mQuotaInfo = aQuotaInfo;
// Always save the directory lock to ensure QuotaManager does not shutdown
// before the Context has gone away.
MOZ_ASSERT(!mDirectoryLock);
mDirectoryLock = aDirectoryLock;
// If we opening the context failed, but we were not explicitly canceled,
// still treat the entire context as canceled. We don't want to allow
// new actions to be dispatched. We also cannot leave the context in
// the INIT state after failing to open.
if (NS_FAILED(aRv)) {
mState = STATE_CONTEXT_CANCELED;
}
if (mState == STATE_CONTEXT_CANCELED) {
for (uint32_t i = 0; i < mPendingActions.Length(); ++i) {
mPendingActions[i].mAction->CompleteOnInitiatingThread(aRv);
}
mPendingActions.Clear();
mThreadsafeHandle->AllowToClose();
// Context will destruct after return here and last ref is released.
return;
}
MOZ_ASSERT(mState == STATE_CONTEXT_INIT);
mState = STATE_CONTEXT_READY;
for (uint32_t i = 0; i < mPendingActions.Length(); ++i) {
DispatchAction(mPendingActions[i].mAction);
}
mPendingActions.Clear();
}
void
Context::AddActivity(Activity* aActivity)
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(aActivity);
MOZ_ASSERT(!mActivityList.Contains(aActivity));
mActivityList.AppendElement(aActivity);
}
void
Context::RemoveActivity(Activity* aActivity)
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(aActivity);
MOZ_ALWAYS_TRUE(mActivityList.RemoveElement(aActivity));
MOZ_ASSERT(!mActivityList.Contains(aActivity));
}
void
Context::NoteOrphanedData()
{
NS_ASSERT_OWNINGTHREAD(Context);
// This may be called more than once
mOrphanedData = true;
}
already_AddRefed<Context::ThreadsafeHandle>
Context::CreateThreadsafeHandle()
{
NS_ASSERT_OWNINGTHREAD(Context);
if (!mThreadsafeHandle) {
mThreadsafeHandle = new ThreadsafeHandle(this);
}
RefPtr<ThreadsafeHandle> ref = mThreadsafeHandle;
return ref.forget();
}
void
Context::SetNextContext(Context* aNextContext)
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(aNextContext);
MOZ_ASSERT(!mNextContext);
mNextContext = aNextContext;
}
void
Context::DoomTargetData()
{
NS_ASSERT_OWNINGTHREAD(Context);
MOZ_ASSERT(mData);
// We are about to drop our reference to the Data. We need to ensure that
// the ~Context() destructor does not run until contents of Data have been
// released on the Target thread.
// Dispatch a no-op Action. This will hold the Context alive through a
// roundtrip to the target thread and back to the owning thread. The
// ref to the Data object is cleared on the owning thread after creating
// the ActionRunnable, but before dispatching it.
RefPtr<Action> action = new NullAction();
DispatchAction(action, true /* doomed data */);
MOZ_ASSERT(!mData);
}
} // namespace cache
} // namespace dom
} // namespace mozilla
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