mojo/edk/embedder/embedder.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 MOJO_EDK_EMBEDDER_EMBEDDER_H_
#define MOJO_EDK_EMBEDDER_EMBEDDER_H_

#include <stddef.h>

#include <string>

#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/shared_memory_handle.h"
#include "base/process/process_handle.h"
#include "base/task_runner.h"
#include "mojo/edk/embedder/configuration.h"
#include "mojo/edk/embedder/scoped_platform_handle.h"
#include "mojo/edk/system/system_impl_export.h"
#include "mojo/public/c/system/types.h"

namespace base {
class PortProvider;
}

namespace mojo {
namespace edk {

using ProcessErrorCallback = base::Callback<void(const std::string& error)>;

// Basic configuration/initialization ------------------------------------------

// Must be called first, or just after setting configuration parameters, to
// initialize the (global, singleton) system state. There is no corresponding
// shutdown operation: once the EDK is initialized, public Mojo C API calls
// remain available for the remainder of the process's lifetime.
MOJO_SYSTEM_IMPL_EXPORT void Init(const Configuration& configuration);

// Like above but uses a default Configuration.
MOJO_SYSTEM_IMPL_EXPORT void Init();

// Sets a default callback to invoke when an internal error is reported but
// cannot be associated with a specific child process. Calling this is optional.
MOJO_SYSTEM_IMPL_EXPORT void SetDefaultProcessErrorCallback(
    const ProcessErrorCallback& callback);

// Basic functions -------------------------------------------------------------
//
// The functions in this section are available once |Init()| has been called and
// provide the embedder with some extra capabilities not exposed by public Mojo
// C APIs.

// Creates a |MojoHandle| that wraps the given |InternalPlatformHandle| (taking
// ownership of it). This |MojoHandle| can then, e.g., be passed through message
// pipes. Note: This takes ownership (and thus closes) |platform_handle| even on
// failure, which is different from what you'd expect from a Mojo API, but it
// makes for a more convenient embedder API.
MOJO_SYSTEM_IMPL_EXPORT MojoResult CreateInternalPlatformHandleWrapper(
    ScopedInternalPlatformHandle platform_handle,
    MojoHandle* platform_handle_wrapper_handle);

// Retrieves the |InternalPlatformHandle| that was wrapped into a |MojoHandle|
// (using |CreateInternalPlatformHandleWrapper()| above). Note that the
// |MojoHandle| is closed on success.
MOJO_SYSTEM_IMPL_EXPORT MojoResult PassWrappedInternalPlatformHandle(
    MojoHandle platform_handle_wrapper_handle,
    ScopedInternalPlatformHandle* platform_handle);

// Initialialization/shutdown for interprocess communication (IPC) -------------

// Retrieves the TaskRunner used for IPC I/O, as set by ScopedIPCSupport.
MOJO_SYSTEM_IMPL_EXPORT scoped_refptr<base::TaskRunner> GetIOTaskRunner();

#if defined(OS_MACOSX) && !defined(OS_IOS)
// Set the |base::PortProvider| for this process. Can be called on any thread,
// but must be set in the root process before any Mach ports can be transferred.
//
// If called at all, this must be called while a ScopedIPCSupport exists.
MOJO_SYSTEM_IMPL_EXPORT void SetMachPortProvider(
    base::PortProvider* port_provider);
#endif

}  // namespace edk
}  // namespace mojo

#endif  // MOJO_EDK_EMBEDDER_EMBEDDER_H_