shell/dynamic_service_runner.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_DYNAMIC_SERVICE_RUNNER_H_
#define SHELL_DYNAMIC_SERVICE_RUNNER_H_

#include "base/callback_forward.h"
#include "base/memory/scoped_ptr.h"
#include "base/native_library.h"
#include "mojo/public/cpp/bindings/interface_request.h"
#include "mojo/public/cpp/system/core.h"

namespace base {
class FilePath;
}

namespace mojo {
class Application;

namespace shell {

class Context;

// Abstraction for loading a service (from the file system) and running it (on
// another thread or in a separate process).
class DynamicServiceRunner {
 public:
  virtual ~DynamicServiceRunner() {}

  // Parameter for |Start| to specify its cleanup behavior.
  enum CleanupBehavior { DeleteAppPath, DontDeleteAppPath };

  // Loads the app in the file at |app_path| and runs it on some other
  // thread/process. If |cleanup_behavior| is |true|, takes ownership of the
  // file. |app_completed_callback| is posted (to the thread on which |Start()|
  // was called) after |MojoMain()| completes.
  virtual void Start(const base::FilePath& app_path,
                     DynamicServiceRunner::CleanupBehavior cleanup_behavior,
                     InterfaceRequest<Application> application_request,
                     const base::Closure& app_completed_callback) = 0;

  // Loads the service in the DSO specificed by |app_path| and prepares it for
  // execution. Runs the DSO's exported function MojoMain().
  // The NativeLibrary is returned and ownership transferred to the caller.
  // This is so if it is unloaded at all, this can be done safely after this
  // thread is destroyed and any thread-local destructors have been executed.
  static base::NativeLibrary LoadAndRunService(
      const base::FilePath& app_path,
      DynamicServiceRunner::CleanupBehavior cleanup_behavior,
      InterfaceRequest<Application> application_request);
};

class DynamicServiceRunnerFactory {
 public:
  virtual ~DynamicServiceRunnerFactory() {}
  virtual scoped_ptr<DynamicServiceRunner> Create(Context* context) = 0;
};

// A generic factory.
template <class DynamicServiceRunnerImpl>
class DynamicServiceRunnerFactoryImpl : public DynamicServiceRunnerFactory {
 public:
  DynamicServiceRunnerFactoryImpl() {}
  virtual ~DynamicServiceRunnerFactoryImpl() {}
  scoped_ptr<DynamicServiceRunner> Create(Context* context) override {
    return scoped_ptr<DynamicServiceRunner>(
        new DynamicServiceRunnerImpl(context));
  }
};

}  // namespace shell
}  // namespace mojo

#endif  // SHELL_DYNAMIC_SERVICE_RUNNER_H_