Refactor ArcSessionRunner part 2.

components/arc/arc_session_runner.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/arc/arc_session_runner.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_runner.h"
 #include "components/arc/arc_session.h"
 
 namespace arc {
 
 namespace {
 
 constexpr base::TimeDelta kDefaultRestartDelay =
     base::TimeDelta::FromSeconds(5);
 
 }  // namespace
 
-ArcSessionRunner::ArcSessionRunner(scoped_refptr<base::TaskRunner> task_runner)
-    : ArcSessionRunner(base::Bind(&ArcSession::Create, this, task_runner)) {}
-
 ArcSessionRunner::ArcSessionRunner(const ArcSessionFactory& factory)
     : restart_delay_(kDefaultRestartDelay),
       factory_(factory),
       weak_ptr_factory_(this) {}
 
 ArcSessionRunner::~ArcSessionRunner() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
   if (arc_session_)
     arc_session_->RemoveObserver(this);
 }
 
+void ArcSessionRunner::AddObserver(ArcSessionObserver* observer) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  observer_list_.AddObserver(observer);
+}
+
+void ArcSessionRunner::RemoveObserver(ArcSessionObserver* observer) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  observer_list_.RemoveObserver(observer);
+}
+
 void ArcSessionRunner::RequestStart() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   // Consecutive RequestStart() call. Do nothing.
   if (run_requested_)
     return;
 
   VLOG(1) << "Session started";
   run_requested_ = true;
   // Here |run_requested_| transitions from false to true. So, |restart_timer_|
   // must be stopped (either not even started, or has been cancelled in
   // previous RequestStop() call).
   DCHECK(!restart_timer_.IsRunning());
 
   if (arc_session_) {
     // In this case, RequestStop() was called, and before |arc_session_| had
     // finished stopping, RequestStart() was called. Do nothing in that case,
     // since when |arc_session_| does actually stop, OnSessionStopped() will
     // be called, where it should automatically restart.
-    DCHECK_EQ(state(), State::STOPPING);
+    DCHECK_EQ(state_, State::STOPPING);
   } else {
-    DCHECK_EQ(state(), State::STOPPED);
+    DCHECK_EQ(state_, State::STOPPED);
     StartArcSession();
   }
 }
 
 void ArcSessionRunner::RequestStop() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   // Consecutive RequestStop() call. Do nothing.
   if (!run_requested_)
     return;
 
   VLOG(1) << "Session ended";
   run_requested_ = false;
 
   if (arc_session_) {
     // The |state_| could be either STARTING, RUNNING or STOPPING.
-    DCHECK_NE(state(), State::STOPPED);
+    DCHECK_NE(state_, State::STOPPED);
 
-    if (state() == State::STOPPING) {
+    if (state_ == State::STOPPING) {
       // STOPPING is found in the senario of "RequestStart() -> RequestStop()
       // -> RequestStart() -> RequestStop()" case.
       // In the first RequestStop() call, |state_| is set to STOPPING,
       // and in the second RequestStop() finds it (so this is the second call).
       // In that case, ArcSession::Stop() is already called, so do nothing.
       return;
     }
-    SetState(State::STOPPING);
+    state_ = State::STOPPING;
     arc_session_->Stop();
   } else {
-    DCHECK_EQ(state(), State::STOPPED);
+    DCHECK_EQ(state_, State::STOPPED);
     // In case restarting is in progress, cancel it.
     restart_timer_.Stop();
   }
 }
 
 void ArcSessionRunner::OnShutdown() {
-  DCHECK(CalledOnValidThread());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   VLOG(1) << "OnShutdown";
   run_requested_ = false;
   restart_timer_.Stop();
   if (arc_session_) {
-    if (state() != State::STOPPING)
-      SetState(State::STOPPING);
+    DCHECK_NE(state_, State::STOPPED);
+    state_ = State::STOPPING;
     arc_session_->OnShutdown();
   }
   // ArcSession::OnShutdown() invokes OnSessionStopped() synchronously.
   // In the observer method, |arc_session_| should be destroyed.
   DCHECK(!arc_session_);
 }
 
+bool ArcSessionRunner::IsRunning() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return state_ == State::RUNNING;
+}
+
+bool ArcSessionRunner::IsStopped() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return state_ == State::STOPPED;
+}
+
 void ArcSessionRunner::SetRestartDelayForTesting(
     const base::TimeDelta& restart_delay) {
-  DCHECK_EQ(state(), State::STOPPED);
+  DCHECK_EQ(state_, State::STOPPED);
   DCHECK(!arc_session_);
   DCHECK(!restart_timer_.IsRunning());
   restart_delay_ = restart_delay;
 }
 
 void ArcSessionRunner::StartArcSession() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_EQ(state(), State::STOPPED);
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, State::STOPPED);
   DCHECK(!arc_session_);
   DCHECK(!restart_timer_.IsRunning());
 
   VLOG(1) << "Starting ARC instance";
-  SetStopReason(StopReason::SHUTDOWN);
   arc_session_ = factory_.Run();
   arc_session_->AddObserver(this);
-  SetState(State::STARTING);
+  state_ = State::STARTING;
   arc_session_->Start();
 }
 
 void ArcSessionRunner::OnSessionReady() {
-  DCHECK(CalledOnValidThread());
-  DCHECK_EQ(state(), State::STARTING);
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, State::STARTING);
   DCHECK(arc_session_);
   DCHECK(!restart_timer_.IsRunning());
 
   VLOG(0) << "ARC ready";
-  SetState(State::RUNNING);
+  state_ = State::RUNNING;
+
+  for (auto& observer : observer_list_)
+    observer.OnSessionReady();
 }
 
 void ArcSessionRunner::OnSessionStopped(StopReason stop_reason) {
-  DCHECK(CalledOnValidThread());
-  DCHECK_NE(state(), State::STOPPED);
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_NE(state_, State::STOPPED);
   DCHECK(arc_session_);
   DCHECK(!restart_timer_.IsRunning());
 
   VLOG(0) << "ARC stopped: " << stop_reason;
   arc_session_->RemoveObserver(this);
   arc_session_.reset();
 
   // If RUNNING, ARC instance unexpectedly crashed so we need to restart it
   // automatically.
   // If STOPPING, at least once RequestStop() is called. If |session_started_|
   // is true, RequestStart() is following so schedule to restart ARC session.
   // Otherwise, do nothing.
   // If STARTING, ARC instance has not been booted properly, so do not
   // restart it automatically.
-  if (state() == State::RUNNING ||
-      (state() == State::STOPPING && run_requested_)) {
-    // This check is for READY case. In RUNNING case |run_requested_| should
-    // be always true, because if once RequestStop() is called, the state()
+  if (state_ == State::RUNNING ||
+      (state_ == State::STOPPING && run_requested_)) {
+    // This check is for RUNNING case. In RUNNING case |run_requested_| should
+    // be always true, because if once RequestStop() is called, the state_
     // will be set to STOPPING.
     DCHECK(run_requested_);
 
     // There was a previous invocation and it crashed for some reason. Try
     // starting ARC instance later again.
     // Note that even |restart_delay_| is 0 (for testing), it needs to
     // PostTask, because observer callback may call RequestStart()/Stop().
     VLOG(0) << "ARC restarting";
     restart_timer_.Start(FROM_HERE, restart_delay_,
                          base::Bind(&ArcSessionRunner::StartArcSession,
                                     weak_ptr_factory_.GetWeakPtr()));
   }
 
   // TODO(hidehiko): Consider to let observers know whether there is scheduled
   // restarting event, or not.
-  SetStopReason(stop_reason);
-  SetState(State::STOPPED);
+  state_ = State::STOPPED;
+  for (auto& observer : observer_list_)
+    observer.OnSessionStopped(stop_reason);
 }
 
 }  // namespace arc