2 // Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
3 // Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
4 // Stefan Bund <g0dil@berlios.de>
6 // This program is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2 of the License, or
9 // (at your option) any later version.
11 // This program is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the
18 // Free Software Foundation, Inc.,
19 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 \brief Connectors public header */
24 /** \defgroup connectors Connector classes
26 A connector has two independent properties
27 \li it may be \e active or \e passive
28 \li it may be an \e input or an \e output
30 \e Active connectors are activated from within the module, \e passive connectors are signaled by
31 the external framework. \e Input modules receive packets, \e output modules send packets.
33 All passive connectors call some onRequest callback whenever I/O needs to be performed. All
34 input modules possess a packet queue.
36 We therefore have 4 connector types: senf::ppi::ActiveInput, senf::ppi::ActiveOutput,
37 senf::ppi::PassiveInput and senf::ppi::PassiveOutput.
40 #ifndef HH_Connectors_
41 #define HH_Connectors_ 1
45 #include <boost/utility.hpp>
46 #include <boost/scoped_ptr.hpp>
47 #include "Utils/SafeBool.hh"
48 #include "Packets/Packets.hh"
50 #include "detail/Callback.hh"
51 #include "Queueing.hh"
53 //#include "Connectors.mpp"
54 ///////////////////////////////hh.p////////////////////////////////////////
60 /** \brief Connector baseclass
62 This connector provides access to the generic connector facilities. This includes the
63 connection management (access to the connected peer) and the containment management (access
64 to the containing module)
70 Connector & peer(); ///< Get peer connected to this connector
71 module::Module & module(); ///< Get this connectors containing module
77 void connect(Connector & target);
80 void setModule(module::Module & module);
83 module::Module * module_;
85 friend class module::Module;
88 /** \brief Passive connector baseclass
90 A passive connector is a connector which is activated externally whenever an I/O request
91 occurs. Passive connectors are the origin of throttling notifications. Depending on the type
92 of connector (output or input) the respective throttling is called forward or backward
95 Passive connectors always handle two throttling states:
97 \li The \e native throttling state is set manually by the module. It is the throttling state
98 originating in the current module
99 \li The \e forwarded throttling state is the state as it is received by throttling
102 The accumulative throttling state is generated by combining all sub-states.
104 class PassiveConnector
105 : public virtual Connector
108 template <class Handler>
109 void onRequest(Handler handler);///< Register I/O event handler
110 /**< The registered handler will be called, whenever packets
111 arrive or should be generated by the module depending
112 on the connector type (input or output). The \a handler
113 argument is either an arbitrary callable object or it
114 is a pointer-to-member to a member of the class which
115 holds this input. In the second case, the pointer will
116 automatically be bound to the containing instance.
118 \param[in] handler Handler to call, whenever an I/O
119 operation is to be performed. */
122 bool throttled(); ///< Get accumulative throttling state
123 bool nativeThrottled(); ///< Get native throttling state
125 void throttle(); ///< Set native throttling
126 void unthrottle(); ///< Revoke native throttling
128 ActiveConnector & peer();
136 void notifyThrottle(); ///< Forward a throttling notification to this connector
137 void notifyUnthrottle(); ///< Forward an unthrottling notification to this connector
139 typedef detail::Callback<>::type Callback;
142 friend class ActiveConnector;
145 /** \brief Active connector baseclass
147 An active connector is a connector which emits I/O requests. Active connectors receive
148 throttling notifications. Depending on the type of connector (input or output) the
149 respective throttling is called forward or backward throttling.
151 Active connectors do not handle any throttling state, they just receive the
152 notifications. These notifications should then either be processed by the module or be
153 forwarded to other connectors.
155 class ActiveConnector
156 : public virtual Connector
159 template <class Handler>
160 void onThrottle(Handler handle); ///< Register throttle notification handler
161 /**< The handler register here will be called, whenever a
162 throttle notification comes in. The \a handler argument
163 is either an arbitrary callable object or it is a
164 pointer-to-member to a member of the class which holds
165 this input. In the second case, the pointer will
166 automatically be bound to the containing instance.
168 \param[in] handle Handler to call on throttle
171 template <class Handler>
172 void onUnthrottle(Handler handle); ///< Register unthrottle notification handler
173 /**< The handler register here will be called, whenever an
174 unthrottle notification comes in. The \a handler
175 argument is either an arbitrary callable object or it
176 is a pointer-to-member to a member of the class which
177 holds this input. In the second case, the pointer will
178 automatically be bound to the containing instance.
180 \param[in] handle Handler to call on unthrottle
183 PassiveConnector & peer();
189 /** \brief Input connector baseclass
191 An input connector receives packets. It may be either an ActiveConnector or a
192 PassiveConnector. An input connector contains a packet queue. This queue enables processing
193 packets in batches or generating multiple output packets from a single input packet. The
194 queues have the potential to greatly simplify the module implementations.
196 \implementation Which container to use?
197 \li list has good insertion and deletion properties on both ends but it costs a dynamic
198 memory allocation for every insertion. A very good property is, that iterators stay
199 valid across insertions/deletions
200 \li vector is fast and has good amortized dynamic allocation properties. However, it is
201 quite unusable as a queue
202 \li deque has comparable dynamic allocation properties as vector but also has good
203 insertion/removal properties on both ends.
205 So probably we will use a deque. I'd like a container which keeps iterators intact on
206 isertion/deletion but I believe that list is just to expensive since every packet will
207 be added to the queue before it can be processed.
210 : public virtual Connector,
211 public SafeBool<InputConnector>
213 typedef std::deque<Packet> Queue;
215 typedef Queue::const_iterator queue_iterator; ///< Iterator type of the embedded queue
216 typedef Queue::size_type size_type; ///< Unsigned type for counting queue elements
218 Packet operator()(); ///< Get a packet
219 /**< This member is the primary method to access received
220 data. On passive connectors, this operator will just
221 dequeue a packet from the packet queue. If the
222 connector is active, the connector will request new
223 packets from the connected module. If the packet
224 request cannot be fulfilled, this is considered to be a
225 logic error in the module implementation and an
226 exception is raised. */
227 bool boolean_test (); ///< Check packet availability
228 /**< Using any input connector in a boolean context will
229 check, whether an input request can be fulfilled. This
230 is always possible if the queue is non-empty. If the
231 input is active, it also returns when the connected
232 passive output is not throttled so new packets can be
235 Calling the operator() member is an error if this test
238 \returns \c true if operator() can be called, \c false
241 OutputConnector & peer();
243 queue_iterator begin(); ///< Access queue begin (head)
244 queue_iterator end(); ///< Access queue past-the-end (tail)
245 Packet peek(); ///< Return head element from the queue
247 size_type queueSize(); ///< Return number of elements in the queue
248 bool empty(); ///< Return queueSize() == 0
254 void enqueue(Packet p);
256 virtual void v_requestEvent();
257 virtual void v_enqueueEvent();
258 virtual void v_dequeueEvent();
262 friend class OutputConnector;
265 /** \brief Output connector baseclass
267 An output connector sends out packets. It may be either an ActiveConnector or a
268 PassiveConnector. An output connector does \e not have an built-in queueing, it relies on
269 the queueing of the connected input.
271 class OutputConnector
272 : public virtual Connector
275 void operator()(Packet p); ///< Send out a packet
277 InputConnector & peer();
284 ///\addtogroup connectors
286 /** \brief Combination of PassiveConnector and InputConnector
288 In addition to the native and the forwarded throttling state, the PassiveInput manages a
289 queue throttling state. This state is automatically managed by a queueing discipline. The
290 standard queueing discipline is ThresholdQueueing, which throttles the connection whenever
291 the queue length reaches the high threshold and unthrottles the connection when the queue
292 reaches the low threshold. The default queueing discipline is
293 <tt>ThresholdQueueing(1,0)</tt> which will throttle the input whenever the queue is
297 : public PassiveConnector, public InputConnector
302 ActiveOutput & peer();
304 template <class QDisc>
305 void qdisc(QDisc const & disc); ///< Change the queueing discipline
306 /**< The queueing discipline is a class which provides the
307 QueueingDiscipline interface.
309 \param[in] disc New queueing discipline */
312 void v_enqueueEvent();
313 void v_dequeueEvent();
315 boost::scoped_ptr<QueueingDiscipline> qdisc_;
316 QueueingDiscipline::State qstate_;
319 /** \brief Combination of PassiveConnector and OutputConnector
322 : public PassiveConnector, public OutputConnector
325 ActiveInput & peer();
327 void connect(ActiveInput & target);
329 friend class ActiveInput;
332 /** \brief Combination of ActiveConnector and InputConnector
335 : public ActiveConnector, public InputConnector
338 PassiveOutput & peer();
340 void request(); ///< request more packets without dequeuing any packet
343 void v_requestEvent();
346 /** \brief Combination of ActiveConnector and OutputConnector
349 : public ActiveConnector, public OutputConnector
352 PassiveInput & peer();
354 void connect(PassiveInput & target);
361 ///////////////////////////////hh.e////////////////////////////////////////
362 #include "Connectors.cci"
363 //#include "Connectors.ct"
364 #include "Connectors.cti"
371 // c-file-style: "senf"
372 // indent-tabs-mode: nil
373 // ispell-local-dictionary: "american"
374 // compile-command: "scons -u test"
375 // comment-column: 40