Move MojoChannelInit to mojo/common

This class has general utility for bootstrapping mojo
services over a variety of communication channels,
so pull it into mojo itself.

BUG=None
TEST=None
R=sky@chromium.org

Review URL: https://codereview.chromium.org/232073002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@264342 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 126 insertions, 0 deletions

diff --git a/mojo/common/DEPS b/mojo/common/DEPS
index a1d21b5..26456c6 100644
--- a/mojo/common/DEPS
+++ b/mojo/common/DEPS
@@ -1,5 +1,6 @@
 include_rules = [
   "-mojo",
   "+mojo/common",
+  "+mojo/embedder",
   "+mojo/public",
 ]
diff --git a/mojo/common/mojo_channel_init.cc b/mojo/common/mojo_channel_init.cc
new file mode 100644
index 0000000..96190f9
--- /dev/null
+++ b/mojo/common/mojo_channel_init.cc
@@ -0,0 +1,59 @@
+// 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 "mojo/common/mojo_channel_init.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "mojo/embedder/embedder.h"
+
+namespace mojo {
+namespace common {
+
+MojoChannelInit::MojoChannelInit()
+    : channel_info_(NULL),
+      weak_factory_(this) {
+}
+
+MojoChannelInit::~MojoChannelInit() {
+  bootstrap_message_pipe_.reset();
+  if (channel_info_) {
+    io_thread_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&mojo::embedder::DestroyChannelOnIOThread, channel_info_));
+  }
+}
+
+void MojoChannelInit::Init(
+    base::PlatformFile file,
+    scoped_refptr<base::TaskRunner> io_thread_task_runner) {
+  DCHECK(!io_thread_task_runner_.get());  // Should only init once.
+  io_thread_task_runner_ = io_thread_task_runner;
+  bootstrap_message_pipe_ = mojo::embedder::CreateChannel(
+      mojo::embedder::ScopedPlatformHandle(
+          mojo::embedder::PlatformHandle(file)),
+      io_thread_task_runner,
+      base::Bind(&MojoChannelInit::OnCreatedChannel, weak_factory_.GetWeakPtr(),
+                 io_thread_task_runner),
+      base::MessageLoop::current()->message_loop_proxy()).Pass();
+}
+
+// static
+void MojoChannelInit::OnCreatedChannel(
+    base::WeakPtr<MojoChannelInit> host,
+    scoped_refptr<base::TaskRunner> io_thread,
+    embedder::ChannelInfo* channel) {
+  // By the time we get here |host| may have been destroyed. If so, shutdown the
+  // channel.
+  if (!host.get()) {
+    io_thread->PostTask(
+        FROM_HERE,
+        base::Bind(&mojo::embedder::DestroyChannelOnIOThread, channel));
+    return;
+  }
+  host->channel_info_ = channel;
+}
+
+}  // namespace common
+}  // namespace mojo
diff --git a/mojo/common/mojo_channel_init.h b/mojo/common/mojo_channel_init.h
new file mode 100644
index 0000000..8fa0094
--- /dev/null
+++ b/mojo/common/mojo_channel_init.h
@@ -0,0 +1,66 @@
+// 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.
+
+#ifndef MOJO_COMMON_MOJO_CHANNEL_INIT_H_
+#define MOJO_COMMON_MOJO_CHANNEL_INIT_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/platform_file.h"
+#include "mojo/common/mojo_common_export.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace base {
+class MessageLoopProxy;
+class TaskRunner;
+}
+
+namespace mojo {
+namespace embedder {
+struct ChannelInfo;
+}
+
+namespace common {
+
+// MojoChannelInit handle creation (and destruction) of the mojo channel. It is
+// expected that this class is created and destroyed on the main thread.
+class MOJO_COMMON_EXPORT MojoChannelInit {
+ public:
+  MojoChannelInit();
+  ~MojoChannelInit();
+
+  // Inits the channel. This takes ownership of |file|.
+  void Init(base::PlatformFile file,
+            scoped_refptr<base::TaskRunner> io_thread_task_runner);
+
+  bool is_handle_valid() const { return bootstrap_message_pipe_.is_valid(); }
+
+  mojo::ScopedMessagePipeHandle bootstrap_message_pipe() {
+    return bootstrap_message_pipe_.Pass();
+  }
+
+ private:
+  // Invoked on the main thread once the channel has been established.
+  static void OnCreatedChannel(
+      base::WeakPtr<MojoChannelInit> host,
+      scoped_refptr<base::TaskRunner> io_thread,
+      embedder::ChannelInfo* channel);
+
+  scoped_refptr<base::TaskRunner> io_thread_task_runner_;
+
+  // If non-null the channel has been established.
+  embedder::ChannelInfo* channel_info_;
+
+  // The handle from channel creation.
+  mojo::ScopedMessagePipeHandle bootstrap_message_pipe_;
+
+  base::WeakPtrFactory<MojoChannelInit> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoChannelInit);
+};
+
+}  // namespace common
+}  // namespace mojo
+
+#endif  // MOJO_COMMON_MOJO_CHANNEL_INIT_H_