Fix Me2Me host to properly reload config when it changes.

remoting/host/remoting_me2me_host.cc

 // Copyright (c) 2012 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.
 //
 // This file implements a standalone host process for Me2Me.
 
 #include <string>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
@@ skipping 115 matching lines @@
       host_config_path_ = cmd_line->GetSwitchValuePath(kHostConfigSwitchName);
     }
     if (!config_.AddConfigPath(host_config_path_)) {
       return false;
     }
 
     return true;
   }
 
   void ConfigUpdated() {
-    // The timer should be set and cleaned up on the same thread.
     DCHECK(message_loop_.message_loop_proxy()->BelongsToCurrentThread());
 
     // Call ConfigUpdatedDelayed after a short delay, so that this object won't
     // try to read the updated configuration file before it has been
     // completely written.
     // If the writer moves the new configuration file into place atomically,
     // this delay may not be necessary.
     config_updated_timer_->Reset();
   }
 
   void ConfigUpdatedDelayed() {
-    if (LoadConfig()) {
+    DCHECK(message_loop_.message_loop_proxy()->BelongsToCurrentThread());
+
+    if (config_.Reload() && LoadConfig()) {

[simonmorris, 2012/08/07 00:43:35]

I think it's more natural to include the call to Reload() within LoadConfig().
Then LoadConfig() is doing the loading, and the call to Reload() won't be
forgotten if LoadConfig() is called from somewhere else.

[Sergey Ulanov, 2012/08/07 00:57:03]

Done. Also changed CompositeHostConfig::AddConfigPath() not to load config.
Instead they are loaded only from CompositeHostConfig::Read().

+      // PostTask to create new authenticator factory in case PIN has changed.
       context_->network_task_runner()->PostTask(
           FROM_HERE,
           base::Bind(&HostProcess::CreateAuthenticatorFactory,
                      base::Unretained(this)));
     } else {
       LOG(ERROR) << "Invalid configuration.";
     }
   }
 
 #if defined(OS_WIN)
@@ skipping 31 matching lines @@
             message_loop_.message_loop_proxy(),
             base::Bind(&HostProcess::ConfigUpdated, base::Unretained(this))));
     config_watcher_.reset(new base::files::FilePathWatcher());
     if (!config_watcher_->Watch(host_config_path_, delegate)) {
       LOG(ERROR) << "Couldn't watch file " << host_config_path_.value();
     }
 #endif
   }
 
   void CreateAuthenticatorFactory() {
+    DCHECK(context_->network_task_runner()->BelongsToCurrentThread());
     scoped_ptr<protocol::AuthenticatorFactory> factory(
         new protocol::Me2MeHostAuthenticatorFactory(
             key_pair_.GenerateCertificate(),
             *key_pair_.private_key(), host_secret_hash_));
     host_->SetAuthenticatorFactory(factory.Pass());
   }
 
   int Run() {
     if (!LoadConfig()) {
       return kInvalidHostConfigurationExitCode;
@@ skipping 34 matching lines @@
  private:
   void StartWatchingPolicy() {
     policy_watcher_.reset(
         policy_hack::PolicyWatcher::Create(context_->file_task_runner()));
     policy_watcher_->StartWatching(
         base::Bind(&HostProcess::OnPolicyUpdate, base::Unretained(this)));
   }
 
   // Read host config, returning true if successful.
   bool LoadConfig() {
+    DCHECK(message_loop_.message_loop_proxy()->BelongsToCurrentThread());
+
+    // TODO(sergeyu): There is a potential race condition: this function is
+    // called on the main thread while the class members it mutates are used on
+    // the network thread. Fix it. http://crbug.com/140986 .
+
     if (!config_.GetString(kHostIdConfigPath, &host_id_)) {
       LOG(ERROR) << "host_id is not defined in the config.";
       return false;
     }
 
     if (!key_pair_.Load(config_)) {
       return false;
     }
 
     std::string host_secret_hash_string;
@@ skipping 373 matching lines @@
             user32.GetFunctionPointer("SetProcessDPIAware"));
     set_process_dpi_aware();
   }
 
   // CommandLine::Init() ignores the passed |argc| and |argv| on Windows getting
   // the command line from GetCommandLineW(), so we can safely pass NULL here.
   return main(0, NULL);
 }
 
 #endif  // defined(OS_WIN)