Remote assistance on Chrome OS Part IV - It2MeHost

remoting/host/it2me/it2me_host.h

 // Copyright 2013 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.
 
 #ifndef REMOTING_HOST_IT2ME_IT2ME_HOST_H_
 #define REMOTING_HOST_IT2ME_IT2ME_HOST_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/signaling/xmpp_signal_strategy.h"
 
 namespace base {
 class DictionaryValue;
 }
 
+namespace policy {
+class PolicyService;
+}  // namespace policy
+
 namespace remoting {
 
 class ChromotingHost;
 class ChromotingHostContext;
 class DesktopEnvironmentFactory;
 class HostEventLogger;
 class HostNPScriptObject;
 class HostStatusLogger;
 class RegisterSupportHostRequest;
 class RsaKeyPair;
 
 namespace policy_hack {
-
 class PolicyWatcher;
-
 }  // namespace policy_hack
 
 // These state values are duplicated in host_session.js. Remember to update
 // both copies when making changes.
 enum It2MeHostState {
   kDisconnected,
   kStarting,
   kRequestedAccessCode,
   kReceivedAccessCode,
   kConnected,
   kDisconnecting,
   kError,
   kInvalidDomainError
 };
 
 // Internal implementation of the plugin's It2Me host function.
 class It2MeHost : public base::RefCountedThreadSafe<It2MeHost>,
                   public HostStatusObserver {
  public:
   class Observer {
    public:
     virtual void OnClientAuthenticated(const std::string& client_username) = 0;
     virtual void OnStoreAccessCode(const std::string& access_code,
                                    base::TimeDelta access_code_lifetime) = 0;
     virtual void OnNatPolicyChanged(bool nat_traversal_enabled) = 0;
     virtual void OnStateChanged(It2MeHostState state) = 0;
   };
 
   It2MeHost(
-      ChromotingHostContext* context,
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      scoped_ptr<ChromotingHostContext> context,
+      scoped_ptr<policy_hack::PolicyWatcher> policy_watcher,
       base::WeakPtr<It2MeHost::Observer> observer,
       const XmppSignalStrategy::XmppServerConfig& xmpp_server_config,
       const std::string& directory_bot_jid);
 
   // Methods called by the script object, from the plugin thread.
 
   // Creates It2Me host structures and starts the host.
   virtual void Connect();
 
   // Disconnects the host, ready for tear-down.
   // Also called internally, from the network thread.
   virtual void Disconnect();
 
   // TODO (weitaosu): Remove RequestNatPolicy from It2MeHost.
   // Request a NAT policy notification.
   virtual void RequestNatPolicy();
 
   // remoting::HostStatusObserver implementation.
   void OnAccessDenied(const std::string& jid) override;
   void OnClientAuthenticated(const std::string& jid) override;
   void OnClientDisconnected(const std::string& jid) override;
 
   void SetStateForTesting(It2MeHostState state) { SetState(state); }
 
  protected:
   friend class base::RefCountedThreadSafe<It2MeHost>;
 
   ~It2MeHost() override;
 
-  ChromotingHostContext* host_context() { return host_context_; }
+  ChromotingHostContext* host_context() { return host_context_.get(); }
   scoped_refptr<base::SingleThreadTaskRunner> task_runner() {
     return task_runner_;
   }
   base::WeakPtr<It2MeHost::Observer> observer() { return observer_; }
 
  private:
   // Updates state of the host. Can be called only on the network thread.
   void SetState(It2MeHostState state);
 
   // Returns true if the host is connected.
@@ skipping 11 matching lines @@
                            const base::TimeDelta& lifetime);
 
   // Shuts down |host_| on the network thread and posts ShutdownOnUiThread()
   // to shut down UI thread resources.
   void ShutdownOnNetworkThread();
 
   // Shuts down |desktop_environment_factory_| and |policy_watcher_| on
   // the UI thread.
   void ShutdownOnUiThread();
 
+  // Called when |policy_watcher_| has stopped listening for changes and it is
+  // safe to delete it.
+  void OnPolicyWatcherShutdown();
+
   // Called when initial policies are read, and when they change.
   void OnPolicyUpdate(scoped_ptr<base::DictionaryValue> policies);
 
   // Handlers for NAT traversal and host domain policies.
   void UpdateNatPolicy(bool nat_traversal_enabled);
   void UpdateHostDomainPolicy(const std::string& host_domain);
 
   // Caller supplied fields.
-
-  // The creator of the It2MeHost object owns the the host context and is
-  // responsible for keeping it alive throughout the liftime of the host.
-  ChromotingHostContext* host_context_;
+  scoped_ptr<ChromotingHostContext> host_context_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::WeakPtr<It2MeHost::Observer> observer_;
   XmppSignalStrategy::XmppServerConfig xmpp_server_config_;
   std::string directory_bot_jid_;
 
   It2MeHostState state_;
 
   scoped_refptr<RsaKeyPair> host_key_pair_;
   scoped_ptr<SignalStrategy> signal_strategy_;
   scoped_ptr<RegisterSupportHostRequest> register_request_;
@@ skipping 23 matching lines @@
   // variable contains the thunk if it is necessary.
   base::Closure pending_connect_;
 
   DISALLOW_COPY_AND_ASSIGN(It2MeHost);
 };
 
 // Having a factory interface makes it possible for the test to provide a mock
 // implementation of the It2MeHost.
 class It2MeHostFactory {
  public:
-  It2MeHostFactory();
+  // |policy_service| is used for creating the policy watcher for new
+  // instances of It2MeHost.  The caller must ensure that |policy_service| is
+  // valid throughout the lifetime of the It2MeHostFactory and each created
+  // It2MeHost object.

[Wez, 2014/10/24 00:28:48]

It2MeHost objects are ref-counted, so how can the caller possibly guarantee
that?

[kelvinp, 2014/10/24 21:39:42]

Comments updated.

+  It2MeHostFactory(policy::PolicyService* policy_service);
   virtual ~It2MeHostFactory();
 
   virtual scoped_refptr<It2MeHost> CreateIt2MeHost(
-      ChromotingHostContext* context,
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      scoped_ptr<ChromotingHostContext> context,
       base::WeakPtr<It2MeHost::Observer> observer,
       const XmppSignalStrategy::XmppServerConfig& xmpp_server_config,
       const std::string& directory_bot_jid);
 
  private:
+  policy::PolicyService* policy_service_;
   DISALLOW_COPY_AND_ASSIGN(It2MeHostFactory);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_IT2ME_IT2ME_HOST_H_