mojo/runner/child_process_host.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MOJO_RUNNER_CHILD_PROCESS_HOST_H_
   6 #define MOJO_RUNNER_CHILD_PROCESS_HOST_H_
   7
   8 #include "base/files/file_path.h"
   9 #include "base/macros.h"
  10 #include "base/process/process.h"
  11 #include "mojo/edk/embedder/channel_info_forward.h"
  12 #include "mojo/edk/embedder/platform_channel_pair.h"
  13 #include "mojo/edk/embedder/scoped_platform_handle.h"
  14 #include "mojo/runner/child_process.mojom.h"
  15 #include "mojo/runner/child_process_host.h"
  16
  17 namespace mojo {
  18 namespace runner {
  19
  20 class Context;
  21
  22 // This class represents a "child process host". Handles launching and
  23 // connecting a platform-specific "pipe" to the child, and supports joining the
  24 // child process. Currently runs a single app (loaded from the file system).
  25 //
  26 // This class is not thread-safe. It should be created/used/destroyed on a
  27 // single thread.
  28 //
  29 // Note: Does not currently work on Windows before Vista.
  30 // Note: After |Start()|, |StartApp| must be called and this object must
  31 // remained alive until the |on_app_complete| callback is called.
  32 class ChildProcessHost {
  33  public:
  34   // |name| is just for debugging ease. We will spawn off a process so that it
  35   // can be sandboxed if |start_sandboxed| is true. |app_path| is a path to the
  36   // mojo application we wish to start.
  37   ChildProcessHost(Context* context,
  38                    bool start_sandboxed,
  39                    const base::FilePath& app_path);
  40   virtual ~ChildProcessHost();
  41
  42   // |Start()|s the child process; calls |DidStart()| (on the thread on which
  43   // |Start()| was called) when the child has been started (or failed to start).
  44   // After calling |Start()|, this object must not be destroyed until
  45   // |DidStart()| has been called.
  46   // TODO(vtl): Consider using weak pointers and removing this requirement.
  47   void Start();
  48
  49   // Waits for the child process to terminate, and returns its exit code.
  50   // Note: If |Start()| has been called, this must not be called until the
  51   // callback has been called.
  52   int Join();
  53
  54   // See |ChildController|:
  55   void StartApp(InterfaceRequest<Application> application_request,
  56                 const ChildController::StartAppCallback& on_app_complete);
  57   void ExitNow(int32_t exit_code);
  58
  59  protected:
  60   // virtual for testing.
  61   virtual void DidStart(bool success);
  62
  63  private:
  64   bool DoLaunch();
  65
  66   void AppCompleted(int32_t result);
  67
  68   // Callback for |embedder::CreateChannel()|.
  69   void DidCreateChannel(embedder::ChannelInfo* channel_info);
  70
  71   Context* const context_;
  72   bool start_sandboxed_;
  73   const base::FilePath app_path_;
  74   base::Process child_process_;
  75   embedder::PlatformChannelPair platform_channel_pair_;
  76   ChildControllerPtr controller_;
  77   embedder::ChannelInfo* channel_info_;
  78   ChildController::StartAppCallback on_app_complete_;
  79
  80   // Platform-specific "pipe" to the child process. Valid immediately after
  81   // creation.
  82   embedder::ScopedPlatformHandle platform_channel_;
  83
  84   DISALLOW_COPY_AND_ASSIGN(ChildProcessHost);
  85 };
  86
  87 }  // namespace runner
  88 }  // namespace mojo
  89
  90 #endif  // MOJO_RUNNER_CHILD_PROCESS_HOST_H_