arc-bridge: Restart ARC instance on crash

components/arc/arc_bridge_service_impl.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_bridge_service_impl.h"
 
 #include <string>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 57 matching lines @@
 }
 
 void ArcBridgeServiceImpl::StopInstance() {
   DCHECK(CalledOnValidThread());
   if (state() == State::STOPPED || state() == State::STOPPING) {
     VLOG(1) << "StopInstance() called when ARC is not running";
     return;
   }
 
   SetState(State::STOPPING);
+  instance_ptr_.reset();
+  if (binding_.is_bound())
+    binding_.Close();
   bootstrap_->Stop();
 }
 
 void ArcBridgeServiceImpl::OnArcAvailable(bool arc_available) {
   DCHECK(CalledOnValidThread());
   if (available() == arc_available)
     return;
   SetAvailable(arc_available);
   PrerequisitesChanged();
 }
 
 void ArcBridgeServiceImpl::OnConnectionEstablished(
     ArcBridgeInstancePtr instance) {
   DCHECK(CalledOnValidThread());
   if (state() != State::CONNECTING) {
     VLOG(1) << "StopInstance() called while connecting";
     return;
   }
 
   instance_ptr_ = std::move(instance);
 
   ArcBridgeHostPtr host;
   binding_.Bind(GetProxy(&host));
   instance_ptr_->Init(std::move(host));
+  instance_ptr_.set_connection_error_handler(base::Bind(

[hidehiko, 2015/12/29 13:27:12]

This should be called before Init() invocation? (I believe at L101 or so?)

[Luis Héctor Chávez, 2015/12/29 17:17:36]

Done.

+      &ArcBridgeServiceImpl::OnChannelClosed, weak_factory_.GetWeakPtr()));
 
   SetState(State::READY);
 }
 
 void ArcBridgeServiceImpl::OnStopped() {
   DCHECK(CalledOnValidThread());
   SetState(State::STOPPED);
+  if (reconnect_) {
+    // There was a previous invocation and it crashed for some reason. Try
+    // starting the container again.
+    reconnect_ = false;
+    PrerequisitesChanged();
+  }
+}
+
+void ArcBridgeServiceImpl::OnChannelClosed() {

[hidehiko, 2015/12/29 13:27:12]

In the following scenario:

- the channel is accidentally closed. (then reconnect_ is set to true).
- Then, host tries to StopInstance() intentionally.

I believe we'd like to stop the instance, but in the current implementation, it
restarts. WDYT?

[Luis Héctor Chávez, 2015/12/29 17:17:36]

In those cases StopInstance() is not called directly. Rather one of the
prerequisites change (either logoff or opt-out), in which case the instance
would not restart.

+  DCHECK(CalledOnValidThread());
+  if (state() == State::STOPPED || state() == State::STOPPING) {
+    // This will happen when the instance is shut down. Ignore that case.
+    return;
+  }
+  VLOG(1) << "Mojo connection lost";
+  CloseAllChannels();
+  reconnect_ = true;
+  StopInstance();
 }
 
 }  // namespace arc