/*
* Copyright 2020 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef PC_CONNECTION_CONTEXT_H_
#define PC_CONNECTION_CONTEXT_H_
#include <memory>
#include <utility>
#include "api/environment/environment.h"
#include "api/packet_socket_factory.h"
#include "api/peer_connection_interface.h"
#include "api/ref_counted_base.h"
#include "api/scoped_refptr.h"
#include "api/sequence_checker.h"
#include "api/transport/sctp_transport_factory_interface.h"
#include "media/base/media_engine.h"
#include "rtc_base/memory/always_valid_pointer.h"
#include "rtc_base/network.h"
#include "rtc_base/network_monitor_factory.h"
#include "rtc_base/socket_factory.h"
#include "rtc_base/thread.h"
#include "rtc_base/thread_annotations.h"
#include "rtc_base/unique_id_generator.h"
namespace webrtc {
// This class contains resources needed by PeerConnection and associated
// objects. A reference to this object is passed to each PeerConnection. The
// methods on this object are assumed not to change the state in any way that
// interferes with the operation of other PeerConnections.
//
// This class must be created and destroyed on the signaling thread.
class ConnectionContext final :
public RefCountedNonVirtual<ConnectionContext> {
public:
// Creates a ConnectionContext. May return null if initialization fails.
// The Dependencies class allows simple management of all new dependencies
// being added to the ConnectionContext.
static scoped_refptr<ConnectionContext> Create(
const Environment& env,
PeerConnectionFactoryDependencies* dependencies);
class MediaEngineReference {
public:
explicit MediaEngineReference(scoped_refptr<ConnectionContext> c)
: c_(std::move(c)) {
if (c_->media_engine()) {
c_->AddRefMediaEngine();
}
}
~MediaEngineReference() {
if (c_->media_engine()) {
c_->ReleaseMediaEngine();
}
}
// Ideally, access to the media engine should be constrained to the worker
// thread. This accessor is provided to help ensure that a reference is held
// and that the call is being issued on the worker thread.
MediaEngineInterface* media_engine()
const;
private:
const scoped_refptr<ConnectionContext> c_;
};
// This class is not copyable or movable.
ConnectionContext(
const ConnectionContext&) =
delete;
ConnectionContext&
operator=(
const ConnectionContext&) =
delete;
// Functions called from PeerConnection and friends
SctpTransportFactoryInterface* sctp_transport_factory()
const {
return sctp_factory_.get();
}
// Const access to the media engine is allowed from the signaling thread.
const MediaEngineInterface* media_engine()
const {
return media_engine_.get();
}
bool is_configured_for_media()
const {
return is_configured_for_media_; }
Thread* signaling_thread() {
return signaling_thread_; }
const Thread* signaling_thread()
const {
return signaling_thread_; }
Thread* worker_thread() {
return worker_thread_.get(); }
const Thread* worker_thread()
const {
return worker_thread_.get(); }
Thread* network_thread() {
return network_thread_; }
const Thread* network_thread()
const {
return network_thread_; }
// Accessors only used from the PeerConnectionFactory class
NetworkManager* default_network_manager()
const {
RTC_DCHECK_RUN_ON(signaling_thread_);
return default_network_manager_.get();
}
PacketSocketFactory* default_socket_factory()
const {
RTC_DCHECK_RUN_ON(signaling_thread_);
return default_socket_factory_.get();
}
MediaFactory* call_factory() {
RTC_DCHECK_RUN_ON(worker_thread());
return call_factory_.get();
}
UniqueRandomIdGenerator* ssrc_generator() {
return &ssrc_generator_; }
// Note: There is lots of code that wants to know whether or not we
// use RTX, but so far, no code has been found that sets it to false.
// Kept in the API in order to ease introduction if we want to resurrect
// the functionality.
bool use_rtx()
const {
return use_rtx_; }
// For use by tests.
void set_use_rtx(
bool use_rtx) { use_rtx_ = use_rtx; }
protected:
friend
class MediaEngineReference;
// Registers a media engine usage. Calls Init() to initialize the media engine
// on the first reference. Must be called on the worker thread.
void AddRefMediaEngine();
// Unregisters a media engine usage. Calls Terminate() to uninitialize the
// media engine on the last reference. Must be called on the worker thread.
void ReleaseMediaEngine();
// Non-const access requires using MediaEngineReference and calling methods
// on the worker thread.
MediaEngineInterface* media_engine_w();
ConnectionContext(
const Environment& env,
PeerConnectionFactoryDependencies* dependencies);
friend
class RefCountedNonVirtual<ConnectionContext>;
~ConnectionContext();
private:
// The following four variables are used to communicate between the
// constructor and the destructor, and are never exposed externally.
bool wraps_current_thread_;
const bool is_configured_for_media_;
std::unique_ptr<SocketFactory> owned_socket_factory_;
std::unique_ptr<Thread> owned_network_thread_
RTC_GUARDED_BY(signaling_thread_);
bool blocking_media_engine_destruction_;
Thread*
const network_thread_;
AlwaysValidPointer<Thread>
const worker_thread_;
Thread*
const signaling_thread_;
// This object is const over the lifetime of the ConnectionContext, and is
// only altered in the destructor.
std::unique_ptr<MediaEngineInterface> media_engine_;
int media_engine_reference_count_ RTC_GUARDED_BY(worker_thread()) =
0;
// This object should be used to generate any SSRC that is not explicitly
// specified by the user (or by the remote party).
// TODO(bugs.webrtc.org/12666): This variable is used from both the signaling
// and worker threads. See if we can't restrict usage to a single thread.
UniqueRandomIdGenerator ssrc_generator_;
std::unique_ptr<NetworkMonitorFactory>
const network_monitor_factory_
RTC_GUARDED_BY(signaling_thread_);
std::unique_ptr<NetworkManager> default_network_manager_
RTC_GUARDED_BY(signaling_thread_);
std::unique_ptr<MediaFactory>
const call_factory_
RTC_GUARDED_BY(worker_thread());
std::unique_ptr<PacketSocketFactory> default_socket_factory_
RTC_GUARDED_BY(signaling_thread_);
std::unique_ptr<SctpTransportFactoryInterface>
const sctp_factory_;
// Controls whether to announce support for the the rfc4588 payload format
// for retransmitted video packets.
bool use_rtx_;
};
}
// namespace webrtc
#endif // PC_CONNECTION_CONTEXT_H_
