genode/repos/os/include/packet_stream_rx/rpc_object.h

/*
 * \brief  Server-side interface for packet-stream reception
 * \author Norman Feske
 * \date   2010-03-01
 */

/*
 * Copyright (C) 2010-2017 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU Affero General Public License version 3.
 */

#ifndef _INCLUDE__PACKET_STREAM_RX__RPC_OBJECT_H_
#define _INCLUDE__PACKET_STREAM_RX__RPC_OBJECT_H_

#include <packet_stream_rx/packet_stream_rx.h>
#include <base/rpc_server.h>

namespace Packet_stream_rx { template <typename> class Rpc_object; }


template <typename CHANNEL>
class Packet_stream_rx::Rpc_object : public Genode::Rpc_object<CHANNEL, Rpc_object<CHANNEL> >
{
	private:

		Genode::Rpc_entrypoint     &_ep;
		Genode::Capability<CHANNEL> _cap { };
		typename CHANNEL::Source    _source;

		Genode::Signal_context_capability _sigh_ready_to_submit;
		Genode::Signal_context_capability _sigh_ack_avail;

	public:

		/**
		 * Constructor
		 *
		 * \param ds            dataspace used as communication buffer
		 *                      for the receive packet stream
		 * \param buffer_alloc  allocator used for managing the communication
		 *                      buffer of the receive packet stream
		 * \param ep            entry point used for serving the channel's RPC
		 *                      interface
		 */
		Rpc_object(Genode::Dataspace_capability  ds,
		           Genode::Region_map           &rm,
		           Genode::Range_allocator      &buffer_alloc,
		           Genode::Rpc_entrypoint       &ep)
		: _ep(ep), _source(ds, rm, buffer_alloc),

		  /* init signal handlers with default handlers of source */
		  _sigh_ready_to_submit(_source.sigh_ready_to_submit()),
		  _sigh_ack_avail(_source.sigh_ack_avail())
		{
			_cap = _ep.manage(this);
		}

		/**
		 * Destructor
		 */
		~Rpc_object() { _ep.dissolve(this); }

		/*
		 * The 'sigh_ack_avail()' and 'sigh_ready_to_submit()' methods
		 * may be called at session-creation time to override the default
		 * data-flow signal handlers as provided by the packet-stream source.
		 * The default handlers let the server block in the event of data
		 * congestion. By installing custom signal handlers, a server
		 * implementation is able to avoid blocking for a single event by
		 * facilitating the use of a select-like mode of operation.
		 *
		 * Note that calling these methods after the finished creation of
		 * the session has no effect because the client queries the signal
		 * handlers only once at session-creation time.
		 */

		/**
		 * Override default handler for server-side ready-to-submit signals
		 *
		 * Must be called at constuction time only.
		 */
		void sigh_ready_to_submit(Genode::Signal_context_capability sigh) {
			_sigh_ready_to_submit = sigh; }

		/**
		 * Override default handler for server-side ack-avail signals
		 *
		 * Must be called at constuction time only.
		 */
		void sigh_ack_avail(Genode::Signal_context_capability sigh) {
			_sigh_ack_avail = sigh; }

		typename CHANNEL::Source *source() { return &_source; }

		Genode::Capability<CHANNEL> cap() const { return _cap; }


		/*******************
		 ** RPC functions **
		 *******************/

		Genode::Dataspace_capability dataspace() { return _source.dataspace(); }

		void sigh_ready_to_ack(Genode::Signal_context_capability sigh) override {
			_source.register_sigh_ready_to_ack(sigh); }

		void sigh_packet_avail(Genode::Signal_context_capability sigh) override {
			_source.register_sigh_packet_avail(sigh); }

		virtual Genode::Signal_context_capability sigh_ready_to_submit() {
			return _sigh_ready_to_submit; }

		virtual Genode::Signal_context_capability sigh_ack_avail() {
			return _sigh_ack_avail; }

};

#endif /* _INCLUDE__PACKET_STREAM_RX__RPC_OBJECT_H_ */