Add CommandBroker::OnTransaction to handle incoming transactions

chromeos/binder/ipc_thread.h

+// 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.
+
+#ifndef CHROMEOS_BINDER_IPC_THREAD_H_
+#define CHROMEOS_BINDER_IPC_THREAD_H_
+
+#include "base/macros.h"
+#include "base/message_loop/message_loop.h"
+#include "base/threading/thread.h"
+#include "chromeos/chromeos_export.h"
+
+namespace binder {
+
+class CommandBroker;
+class Driver;
+
+// IpcThread manages binder-related resources (e.g. binder driver FD) and
+// handles incoming binder commands.

[satorux1, 2016/01/14 06:34:18]

Is it OK to instantiate this class and call Start() from a non-blocking thread
like UI thread? Would be nice to document.

[hashimoto, 2016/01/14 06:49:38]

It's OK to do that like all other base::Thread sub-classes.
Do you think this class is doing something tricky when starting thread so it
needs special comments?
If not, I'd like to avoid having redundant comments.

[satorux1, 2016/01/14 07:07:13]

I felt this class was tricky because it deals with the binder driver.

[hashimoto, 2016/01/14 08:52:03]

It deals with the binder driver, but all meaningful things happen on the thread
managed by this object.
As this class follows the standard way in which most base::Thread sub-classes
are implemented, I'd rather let the reader reference base/threading/thread.h for
that kind of information.

+class CHROMEOS_EXPORT IpcThread : public base::Thread,
+                                  public base::MessageLoopForIO::Watcher {
+ public:
+  IpcThread();
+  ~IpcThread() override;
+
+  Driver* driver() { return driver_.get(); }
+  CommandBroker* command_broker() { return command_broker_.get(); }
+  bool initialized() const { return initialized_; }
+
+  // Starts this thread.
+  // Returns true on success.
+  bool Start();
+
+  // base::MessageLoopIO::Watcher overrides:
+  void OnFileCanReadWithoutBlocking(int fd) override;
+  void OnFileCanWriteWithoutBlocking(int fd) override;
+
+ protected:
+  // base::Thread overrides:
+  void Init() override;
+  void CleanUp() override;
+
+ private:
+  scoped_ptr<Driver> driver_;
+  scoped_ptr<CommandBroker> command_broker_;
+  scoped_ptr<base::MessageLoopForIO::FileDescriptorWatcher> watcher_;
+  bool initialized_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(IpcThread);
+};
+
+}  // namespace binder
+
+#endif  // CHROMEOS_BINDER_IPC_THREAD_H_