Monitor the ShellClient binding for pipe closure as a signal to shut down the ShellConnection, rath…

mojo/shell/public/cpp/lib/shell_connection.cc

 // Copyright 2014 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 "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
 #include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/lib/connection_impl.h"
@@ skipping 20 matching lines @@
   binding_.WaitForIncomingMethodCall();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ShellConnection, shell::mojom::ShellClient implementation:
 
 void ShellConnection::Initialize(shell::mojom::ConnectorPtr connector,
                                  const mojo::String& name,
                                  uint32_t id,
                                  uint32_t user_id) {
-  connector_.reset(new ConnectorImpl(
-      std::move(connector),
+  connector_.reset(new ConnectorImpl(std::move(connector)));
+  binding_.set_connection_error_handler(
       base::Bind(&ShellConnection::OnConnectionError,
-                 weak_factory_.GetWeakPtr())));
+                 weak_factory_.GetWeakPtr()));
   client_->Initialize(connector_.get(), name, id, user_id);
 }
 
 void ShellConnection::AcceptConnection(
     const String& requestor_name,
     uint32_t requestor_id,
     uint32_t requestor_user_id,
     shell::mojom::InterfaceProviderRequest local_interfaces,
     shell::mojom::InterfaceProviderPtr remote_interfaces,
     Array<String> allowed_interfaces,
     const String& name) {
   scoped_ptr<Connection> registry(new internal::ConnectionImpl(
       name, requestor_name, requestor_id, requestor_user_id,
       std::move(remote_interfaces), std::move(local_interfaces),
       allowed_interfaces.To<std::set<std::string>>()));
   if (!client_->AcceptConnection(registry.get()))
     return;
 
   // TODO(beng): it appears we never prune this list. We should, when the
   //             connection's remote service provider pipe breaks.
   incoming_connections_.push_back(std::move(registry));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ShellConnection, private:
 
 void ShellConnection::OnConnectionError() {
-  // We give the client notice first, since it might want to do something on
-  // shell connection errors other than immediate termination of the run
-  // loop. The application might want to continue servicing connections other
-  // than the one to the shell.
-  if (client_->ShellConnectionLost())
-    connector_.reset();
+  // Note that the ShellClient doesn't technically have to quit now, it may live
+  // on to service existing connections. All existing Connectors however are
+  // invalid.
+  client_->ShellConnectionLost();
+  // We don't reset the connector as clients may have taken a raw pointer to it.
+  // Connect() will return nullptr if they try to connect to anything.
 }
 
 }  // namespace mojo