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44 #ifndef __MEM_PACKET_QUEUE_HH__
45 #define __MEM_PACKET_QUEUE_HH__
49 * Declaration of a simple PacketQueue that is associated with
50 * a port on which it attempts to send packets according to the time
51 * stamp given to them at insertion. The packet queue is responsible
52 * for the flow control of the port.
57 #include "mem/port.hh"
58 #include "sim/drain.hh"
59 #include "sim/eventq_impl.hh"
62 * A packet queue is a class that holds deferred packets and later
63 * sends them using the associated slave port or master port.
65 class PacketQueue : public Drainable
68 /** A deferred packet, buffered to transmit later. */
69 class DeferredPacket {
71 Tick tick; ///< The tick when the packet is ready to transmit
72 PacketPtr pkt; ///< Pointer to the packet to transmit
73 DeferredPacket(Tick t, PacketPtr p)
78 typedef std::list<DeferredPacket> DeferredPacketList;
80 /** A list of outgoing packets. */
81 DeferredPacketList transmitList;
83 /** The manager which is used for the event queue */
86 /** Used to schedule sending of deferred packets. */
87 void processSendEvent();
89 /** Event used to call processSendEvent. */
90 EventFunctionWrapper sendEvent;
93 * Optionally disable the sanity check
94 * on the size of the transmitList. The
95 * sanity check will be enabled by default.
97 bool _disableSanityCheck;
101 /** Label to use for print request packets label stack. */
102 const std::string label;
104 /** Remember whether we're awaiting a retry. */
107 /** Check whether we have a packet ready to go on the transmit list. */
108 bool deferredPacketReady() const
109 { return !transmitList.empty() && transmitList.front().tick <= curTick(); }
112 * Attempt to send a packet. Note that a subclass of the
113 * PacketQueue can override this method and thus change the
114 * behaviour (as done by the cache for the request queue). The
115 * default implementation sends the head of the transmit list. The
116 * caller must guarantee that the list is non-empty and that the
117 * head packet is scheduled for curTick() (or earlier).
119 virtual void sendDeferredPacket();
122 * Send a packet using the appropriate method for the specific
123 * subclass (reuest, response or snoop response).
125 virtual bool sendTiming(PacketPtr pkt) = 0;
128 * Create a packet queue, linked to an event manager, and a label
129 * that will be used for functional print request packets.
131 * @param _em Event manager used for scheduling this queue
132 * @param _label Label to push on the label stack for print request packets
133 * @param disable_sanity_check Flag used to disable the sanity check
134 * on the size of the transmitList. The check is enabled by default.
136 PacketQueue(EventManager& _em, const std::string& _label,
137 const std::string& _sendEventName,
138 bool disable_sanity_check = false);
141 * Virtual desctructor since the class may be used as a base class.
143 virtual ~PacketQueue();
148 * Provide a name to simplify debugging.
150 * @return A complete name, appended to module and port
152 virtual const std::string name() const = 0;
155 * Get the size of the queue.
157 size_t size() const { return transmitList.size(); }
160 * Get the next packet ready time.
162 Tick deferredPacketReadyTime() const
163 { return transmitList.empty() ? MaxTick : transmitList.front().tick; }
166 * Check if a packets address exists in the queue.
168 bool hasAddr(Addr addr) const;
170 /** Check the list of buffered packets against the supplied
171 * functional request. */
172 bool checkFunctional(PacketPtr pkt);
175 * Schedule a send event if we are not already waiting for a
176 * retry. If the requested time is before an already scheduled
177 * send event, the event will be rescheduled. If MaxTick is
178 * passed, no event is scheduled. Instead, if we are idle and
179 * asked to drain then check and signal drained.
181 * @param when time to schedule an event
183 void schedSendEvent(Tick when);
186 * Add a packet to the transmit list, and schedule a send event.
188 * @param pkt Packet to send
189 * @param when Absolute time (in ticks) to send packet
190 * @param force_order Force insertion order for packets with same address
192 void schedSendTiming(PacketPtr pkt, Tick when, bool force_order = false);
195 * Retry sending a packet from the queue. Note that this is not
196 * necessarily the same packet if something has been added with an
197 * earlier time stamp.
202 * This allows a user to explicitly disable the sanity check
203 * on the size of the transmitList, which is enabled by default.
204 * Users must use this function to explicitly disable the sanity
207 void disableSanityCheck() { _disableSanityCheck = true; }
209 DrainState drain() override;
212 class ReqPacketQueue : public PacketQueue
217 MasterPort& masterPort;
219 // Static definition so it can be called when constructing the parent
220 // without us being completely initialized.
221 static const std::string name(const MasterPort& masterPort,
222 const std::string& label)
223 { return masterPort.name() + "-" + label; }
228 * Create a request packet queue, linked to an event manager, a
229 * master port, and a label that will be used for functional print
232 * @param _em Event manager used for scheduling this queue
233 * @param _masterPort Master port used to send the packets
234 * @param _label Label to push on the label stack for print request packets
236 ReqPacketQueue(EventManager& _em, MasterPort& _masterPort,
237 const std::string _label = "ReqPacketQueue");
239 virtual ~ReqPacketQueue() { }
241 const std::string name() const
242 { return name(masterPort, label); }
244 bool sendTiming(PacketPtr pkt);
248 class SnoopRespPacketQueue : public PacketQueue
253 MasterPort& masterPort;
255 // Static definition so it can be called when constructing the parent
256 // without us being completely initialized.
257 static const std::string name(const MasterPort& masterPort,
258 const std::string& label)
259 { return masterPort.name() + "-" + label; }
264 * Create a snoop response packet queue, linked to an event
265 * manager, a master port, and a label that will be used for
266 * functional print request packets.
268 * @param _em Event manager used for scheduling this queue
269 * @param _masterPort Master port used to send the packets
270 * @param _label Label to push on the label stack for print request packets
272 SnoopRespPacketQueue(EventManager& _em, MasterPort& _masterPort,
273 const std::string _label = "SnoopRespPacketQueue");
275 virtual ~SnoopRespPacketQueue() { }
277 const std::string name() const
278 { return name(masterPort, label); }
280 bool sendTiming(PacketPtr pkt);
284 class RespPacketQueue : public PacketQueue
289 SlavePort& slavePort;
291 // Static definition so it can be called when constructing the parent
292 // without us being completely initialized.
293 static const std::string name(const SlavePort& slavePort,
294 const std::string& label)
295 { return slavePort.name() + "-" + label; }
300 * Create a response packet queue, linked to an event manager, a
301 * slave port, and a label that will be used for functional print
304 * @param _em Event manager used for scheduling this queue
305 * @param _slavePort Slave port used to send the packets
306 * @param _label Label to push on the label stack for print request packets
308 RespPacketQueue(EventManager& _em, SlavePort& _slavePort,
309 const std::string _label = "RespPacketQueue");
311 virtual ~RespPacketQueue() { }
313 const std::string name() const
314 { return name(slavePort, label); }
316 bool sendTiming(PacketPtr pkt);
320 #endif // __MEM_PACKET_QUEUE_HH__