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 void notifyThrottle(); ///< Forward a throttling notification to this connector
129 void notifyUnthrottle(); ///< Forward an unthrottling notification to this connector
131 ActiveConnector & peer();
140 typedef detail::Callback<>::type Callback;
144 /** \brief Active connector baseclass
146 An active connector is a connector which emits I/O requests. Active connectors receive
147 throttling notifications. Depending on the type of connector (input or output) the
148 respective throttling is called forward or backward throttling.
150 Active connectors do not handle any throttling state, they just receive the
151 notifications. These notifications should then either be processed by the module or be
152 forwarded to other connectors.
154 class ActiveConnector
155 : public virtual Connector
158 template <class Handler>
159 void onThrottle(Handler handle); ///< Register throttle notification handler
160 /**< The handler register here will be called, whenever a
161 throttle notification comes in. The \a handler argument
162 is either an arbitrary callable object or it is a
163 pointer-to-member to a member of the class which holds
164 this input. In the second case, the pointer will
165 automatically be bound to the containing instance.
167 \param[in] handle Handler to call on throttle
170 template <class Handler>
171 void onUnthrottle(Handler handle); ///< Register unthrottle notification handler
172 /**< The handler register here will be called, whenever an
173 unthrottle notification comes in. The \a handler
174 argument is either an arbitrary callable object or it
175 is a pointer-to-member to a member of the class which
176 holds this input. In the second case, the pointer will
177 automatically be bound to the containing instance.
179 \param[in] handle Handler to call on unthrottle
182 PassiveConnector & peer();
188 /** \brief Input connector baseclass
190 An input connector receives packets. It may be either an ActiveConnector or a
191 PassiveConnector. An input connector contains a packet queue. This queue enables processing
192 packets in batches or generating multiple output packets from a single input packet. The
193 queues have the potential to greatly simplify the module implementations.
195 \implementation Which container to use?
196 \li list has good insertion and deletion properties on both ends but it costs a dynamic
197 memory allocation for every insertion. A very good property is, that iterators stay
198 valid across insertions/deletions
199 \li vector is fast and has good amortized dynamic allocation properties. However, it is
200 quite unusable as a queue
201 \li deque has comparable dynamic allocation properties as vector but also has good
202 insertion/removal properties on both ends.
204 So probably we will use a deque. I'd like a container which keeps iterators intact on
205 isertion/deletion but I believe that list is just to expensive since every packet will
206 be added to the queue before it can be processed.
209 : public virtual Connector,
210 public SafeBool<InputConnector>
212 typedef std::deque<Packet> Queue;
214 typedef Queue::const_iterator queue_iterator; ///< Iterator type of the embedded queue
215 typedef Queue::size_type size_type; ///< Unsigned type for counting queue elements
217 Packet operator()(); ///< Get a packet
218 /**< This member is the primary method to access received
219 data. On passive connectors, this operator will just
220 dequeue a packet from the packet queue. If the
221 connector is active, the connector will request new
222 packets from the connected module. If the packet
223 request cannot be fulfilled, this is considered to be a
224 logic error in the module implementation and an
225 exception is raised. */
226 bool boolean_test (); ///< Check packet availability
227 /**< Using any input connector in a boolean context will
228 check, whether an input request can be fulfilled. This
229 is always possible if the queue is non-empty. If the
230 input is active, it also returns when the connected
231 passive output is not throttled so new packets can be
234 Calling the operator() member is an error if this test
237 \returns \c true if operator() can be called, \c false
240 OutputConnector & peer();
242 queue_iterator begin(); ///< Access queue begin (head)
243 queue_iterator end(); ///< Access queue past-the-end (tail)
244 Packet peek(); ///< Return head element from the queue
246 size_type queueSize(); ///< Return number of elements in the queue
247 bool empty(); ///< Return queueSize() == 0
253 void enqueue(Packet p);
255 virtual void v_requestEvent();
256 virtual void v_enqueueEvent();
257 virtual void v_dequeueEvent();
261 friend class OutputConnector;
264 /** \brief Output connector baseclass
266 An output connector sends out packets. It may be either an ActiveConnector or a
267 PassiveConnector. An output connector does \e not have an built-in queueing, it relies on
268 the queueing of the connected input.
270 class OutputConnector
271 : public virtual Connector
274 void operator()(Packet p); ///< Send out a packet
276 InputConnector & peer();
283 ///\addtogroup connectors
285 /** \brief Combination of PassiveConnector and InputConnector
287 In addition to the native and the forwarded throttling state, the PassiveInput manages a
288 queue throttling state. This state is automatically managed by a queueing discipline. The
289 standard queueing discipline is ThresholdQueueing, which throttles the connection whenever
290 the queue length reaches the high threshold and unthrottles the connection when the queue
291 reaches the low threshold. The default queueing discipline is
292 <tt>ThresholdQueueing(1,0)</tt> which will throttle the input whenever the queue is
296 : public PassiveConnector, public InputConnector
301 ActiveOutput & peer();
303 template <class QDisc>
304 void qdisc(QDisc const & disc); ///< Change the queueing discipline
305 /**< The queueing discipline is a class which provides the
306 QueueingDiscipline interface.
308 \param[in] disc New queueing discipline */
311 void v_enqueueEvent();
312 void v_dequeueEvent();
314 boost::scoped_ptr<QueueingDiscipline> qdisc_;
315 QueueingDiscipline::State qstate_;
318 /** \brief Combination of PassiveConnector and OutputConnector
321 : public PassiveConnector, public OutputConnector
324 ActiveInput & peer();
326 void connect(ActiveInput & target);
328 friend class ActiveInput;
331 /** \brief Combination of ActiveConnector and InputConnector
334 : public ActiveConnector, public InputConnector
337 PassiveOutput & peer();
339 void request(); ///< request more packets without dequeuing any packet
342 void v_requestEvent();
345 /** \brief Combination of ActiveConnector and OutputConnector
348 : public ActiveConnector, public OutputConnector
351 ActiveInput & peer();
353 void connect(PassiveInput & target);
360 ///////////////////////////////hh.e////////////////////////////////////////
361 #include "Connectors.cci"
362 //#include "Connectors.ct"
363 #include "Connectors.cti"
370 // c-file-style: "senf"
371 // indent-tabs-mode: nil
372 // ispell-local-dictionary: "american"
373 // compile-command: "scons -u test"
374 // comment-column: 40