Get mojo_shell building inside chromium checkout.

mojo/shell/child_process_host.h

+// 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 SHELL_CHILD_PROCESS_HOST_H_
+#define SHELL_CHILD_PROCESS_HOST_H_
+
+#include "base/macros.h"
+#include "base/process/process.h"
+#include "mojo/edk/embedder/platform_channel_pair.h"
+#include "mojo/edk/embedder/scoped_platform_handle.h"
+#include "mojo/shell/child_process.h"  // For |ChildProcess::Type|.
+
+namespace mojo {
+namespace shell {
+
+class Context;
+
+// (Base) class for a "child process host". Handles launching and connecting a
+// platform-specific "pipe" to the child, and supports joining the child
+// process.
+//
+// This class is not thread-safe. It should be created/used/destroyed on a
+// single thread.
+//
+// Note: Does not currently work on Windows before Vista.
+class ChildProcessHost {
+ public:
+  explicit ChildProcessHost(Context* context);
+  virtual ~ChildProcessHost();
+
+  // |Start()|s the child process; calls |DidStart()| (on the thread on which
+  // |Start()| was called) when the child has been started (or failed to start).
+  // After calling |Start()|, this object must not be destroyed until
+  // |DidStart()| has been called.
+  // TODO(vtl): Consider using weak pointers and removing this requirement.
+  void Start();
+
+  // Waits for the child process to terminate, and returns its exit code.
+  // Note: If |Start()| has been called, this must not be called until the
+  // callback has been called.
+  int Join();
+
+  embedder::ScopedPlatformHandle* platform_channel() {
+    return &platform_channel_;
+  }
+
+  virtual void WillStart() = 0;
+  virtual void DidStart(bool success) = 0;
+
+ protected:
+  Context* context() const { return context_; }
+
+ private:
+  bool DoLaunch();
+
+  Context* const context_;
+
+  base::Process child_process_;
+
+  embedder::PlatformChannelPair platform_channel_pair_;
+
+  // Platform-specific "pipe" to the child process. Valid immediately after
+  // creation.
+  embedder::ScopedPlatformHandle platform_channel_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChildProcessHost);
+};
+
+}  // namespace shell
+}  // namespace mojo
+
+#endif  // SHELL_CHILD_PROCESS_HOST_H_