chromium/mojo/public/interfaces/bindings/pipe_control_messages.mojom

// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

[JavaPackage="org.chromium.mojo.bindings.pipecontrol"]
module mojo.pipe_control;

// For each message pipe running user-defined interfaces, some control
// functions are provided and used by the routers at both ends of the pipe, so
// that they can coordinate to manage interface endpoints.
// All these control messages will have the interface ID field in the message
// header set to invalid.

////////////////////////////////////////////////////////////////////////////////
// RunOrClosePipe@0xFFFFFFFE(RunOrClosePipeInput input);
//
// This control function runs the input command. If the operation fails or the
// command is not supported, the message pipe is closed.

const uint32 kRunOrClosePipeMessageId = 0xFFFFFFFE;

struct RunOrClosePipeMessageParams {
  RunOrClosePipeInput input;
};

union RunOrClosePipeInput {
  PeerAssociatedEndpointClosedEvent peer_associated_endpoint_closed_event;
  PauseUntilFlushCompletes pause_until_flush_completes;
  FlushAsync flush_async;
};

// A user-defined reason about why the interface is disconnected.
struct DisconnectReason {
  uint32 custom_reason;
  string description;
};

// An event to notify that an interface endpoint set up at the message sender
// side has been closed.
//
// This event is omitted if the endpoint belongs to the primary interface and
// there is no disconnect reason specified.
struct PeerAssociatedEndpointClosedEvent {
  // The interface ID.
  uint32 id;
  DisconnectReason? disconnect_reason;
};

// Sent to an endpoint to pause its message dispatch. |flush_pipe| is
// monitored asynchronously for peer closure. Once its peer is closed, the
// endpoint unpauses.
struct PauseUntilFlushCompletes {
  handle<message_pipe> flush_pipe;
};

// Sent to an endpoint so that the flush operation corresponding to
// |flusher_pipe| is signaled by the endpoint's receipt of this message.
struct FlushAsync {
  handle<message_pipe> flusher_pipe;
};