Initial implementation of an IPC adapter to expose Chrome IPC to Native Client.

chrome/nacl/nacl_ipc_manager.h

+// 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.
+
+#ifndef CHROME_NACL_NACL_IPC_MANAGER_H_
+#define CHROME_NACL_NACL_IPC_MANAGER_H_
+#pragma once
+
+#include <map>
+
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "ipc/ipc_channel_handle.h"
+
+class NaClIPCAdapter;
+
+// This class manages all IPC channels exposed to NaCl. It mostly just provides
+// a threadsafe (since nacl send/recvmsg functions can be called on any thread)
+// map from handle to our IPC adapters.

[bbudge, 2012/03/27 18:38:37]

It seems like it would be better if this comment explained about the use of this
class rather than the implementation. It wasn't obvious to me at first that
NaCLIPCAdapters weren't used directly.

+class NaClIPCManager {
+ public:
+  NaClIPCManager();
+  ~NaClIPCManager();
+
+  // Creates a nacl channel associated with the given channel handle (normally
+  // this will come from the browser process). Returns the handle that should
+  // be given to nacl to associated with this IPC channel.
+  void* CreateChannel(const IPC::ChannelHandle& handle);
+
+  // Destroys the channel with the given handle.
+  void DestroyChannel(void* handle);
+
+  // Implementation of sendmsg on the given channel. The return value is the
+  // number of bytes written or -1 on failure.
+  int SendMessage(void* handle, const char* data, int data_length);
+
+  // Implementation of recvmsg on the given channel. The return value is the
+  // number of bytes received or -1 on failure.
+  int ReceiveMessage(void* handle, char* buffer, int buffer_length);
+
+ private:
+  // Looks up the adapter if given a handle. The pointer wil be null on
+  // failures.
+  scoped_refptr<NaClIPCAdapter> GetAdapter(void* handle);
+
+  // Lock around all data below.
+  base::Lock lock_;
+
+  // All active IPC channels. Locked by lock_ above.
+  typedef std::map<void*, scoped_refptr<NaClIPCAdapter> > AdapterMap;
+  AdapterMap adapters_;
+
+  DISALLOW_COPY_AND_ASSIGN(NaClIPCManager);
+};
+
+#endif  // CHROME_NACL_NACL_IPC_MANAGER_H_