blob: 6743222bef081a97b80df4e89dff9289217f0a15 [file] [log] [blame]
// Copyright 2015 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.
#include <stdint.h>
#include <memory>
#include <queue>
#include "base/macros.h"
#include "mojo/edk/system/atomic_flag.h"
#include "mojo/edk/system/awakable_list.h"
#include "mojo/edk/system/dispatcher.h"
#include "mojo/edk/system/message_for_transit.h"
#include "mojo/edk/system/ports/port_ref.h"
namespace mojo {
namespace edk {
class NodeController;
class MessagePipeDispatcher : public Dispatcher {
// Constructs a MessagePipeDispatcher permanently tied to a specific port.
// |connected| must indicate the state of the port at construction time; if
// the port is initialized with a peer, |connected| must be true. Otherwise it
// must be false.
// A MessagePipeDispatcher may not be transferred while in a disconnected
// state, and one can never return to a disconnected once connected.
// |pipe_id| is a unique identifier which can be used to track pipe endpoints
// as they're passed around. |endpoint| is either 0 or 1 and again is only
// used for tracking pipes (one side is always 0, the other is always 1.)
MessagePipeDispatcher(NodeController* node_controller,
const ports::PortRef& port,
uint64_t pipe_id,
int endpoint);
// Fuses this pipe with |other|. Returns |true| on success or |false| on
// failure. Regardless of the return value, both dispatchers are closed by
// this call.
bool Fuse(MessagePipeDispatcher* other);
// Dispatcher:
Type GetType() const override;
MojoResult Close() override;
MojoResult Watch(MojoHandleSignals signals,
const Watcher::WatchCallback& callback,
uintptr_t context) override;
MojoResult CancelWatch(uintptr_t context) override;
MojoResult WriteMessage(std::unique_ptr<MessageForTransit> message,
MojoWriteMessageFlags flags) override;
MojoResult ReadMessage(std::unique_ptr<MessageForTransit>* message,
uint32_t* num_bytes,
MojoHandle* handles,
uint32_t* num_handles,
MojoReadMessageFlags flags,
bool read_any_size) override;
HandleSignalsState GetHandleSignalsState() const override;
MojoResult AddAwakable(Awakable* awakable,
MojoHandleSignals signals,
uintptr_t context,
HandleSignalsState* signals_state) override;
void RemoveAwakable(Awakable* awakable,
HandleSignalsState* signals_state) override;
void StartSerialize(uint32_t* num_bytes,
uint32_t* num_ports,
uint32_t* num_handles) override;
bool EndSerialize(void* destination,
ports::PortName* ports,
PlatformHandle* handles) override;
bool BeginTransit() override;
void CompleteTransitAndClose() override;
void CancelTransit() override;
static scoped_refptr<Dispatcher> Deserialize(
const void* data,
size_t num_bytes,
const ports::PortName* ports,
size_t num_ports,
PlatformHandle* handles,
size_t num_handles);
class PortObserverThunk;
friend class PortObserverThunk;
~MessagePipeDispatcher() override;
MojoResult CloseNoLock();
HandleSignalsState GetHandleSignalsStateNoLock() const;
void OnPortStatusChanged();
// These are safe to access from any thread without locking.
NodeController* const node_controller_;
const ports::PortRef port_;
const uint64_t pipe_id_;
const int endpoint_;
// Guards access to all the fields below.
mutable base::Lock signal_lock_;
// This is not the same is |port_transferred_|. It's only held true between
// BeginTransit() and Complete/CancelTransit().
AtomicFlag in_transit_;
bool port_transferred_ = false;
AtomicFlag port_closed_;
AwakableList awakables_;
} // namespace edk
} // namespace mojo