1/*
2 * Copyright (c) 2000-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Steve Reinhardt
29 * Nathan Binkert
30 * Steve Raasch
31 */
32
33#include <assert.h>
34
35#include <iostream>
36#include <string>
37#include <vector>
38
39#include "cpu/smt.hh"
40#include "base/misc.hh"
41
42#include "sim/eventq.hh"
43#include "base/trace.hh"
44#include "sim/root.hh"
45
46using namespace std;
47
48//
49// Main Event Queue
50//
51// Events on this queue are processed at the *beginning* of each
52// cycle, before the pipeline simulation is performed.
53//
54EventQueue mainEventQueue("MainEventQueue");
55
56void
57EventQueue::insert(Event *event)
58{
59 if (head == NULL || event->when() < head->when() ||
60 (event->when() == head->when() &&
61 event->priority() <= head->priority())) {
62 event->next = head;
63 head = event;
64 } else {
65 Event *prev = head;
66 Event *curr = head->next;
67
68 while (curr) {
69 if (event->when() <= curr->when() &&
70 (event->when() < curr->when() ||
71 event->priority() <= curr->priority()))
72 break;
73
74 prev = curr;
75 curr = curr->next;
76 }
77
78 event->next = curr;
79 prev->next = event;
80 }
81}
82
83void
84EventQueue::remove(Event *event)
85{
86 if (head == NULL)
87 return;
88
89 if (head == event){
90 head = event->next;
91 return;
92 }
93
94 Event *prev = head;
95 Event *curr = head->next;
96 while (curr && curr != event) {
97 prev = curr;
98 curr = curr->next;
99 }
100
101 if (curr == event)
102 prev->next = curr->next;
103}
104
105Event *
106EventQueue::serviceOne()
107{
108 Event *event = head;
109 event->clearFlags(Event::Scheduled);
110 head = event->next;
111
112 // handle action
113 if (!event->squashed()) {
114 event->process();
115 if (event->isExitEvent()) {
116 assert(!event->getFlags(Event::AutoDelete)); // would be silly
117 return event;
118 }
119 } else {
120 event->clearFlags(Event::Squashed);
121 }
122
123 if (event->getFlags(Event::AutoDelete) && !event->scheduled())
124 delete event;
125
126 return NULL;
127}
128
129
130void
131Event::serialize(std::ostream &os)
132{
133 SERIALIZE_SCALAR(_when);
134 SERIALIZE_SCALAR(_priority);
135 SERIALIZE_ENUM(_flags);
136}
137
138
139void
140Event::unserialize(Checkpoint *cp, const string &section)
141{
142 if (scheduled())
143 deschedule();
144
145 UNSERIALIZE_SCALAR(_when);
146 UNSERIALIZE_SCALAR(_priority);
147
148 // need to see if original event was in a scheduled, unsquashed
149 // state, but don't want to restore those flags in the current
150 // object itself (since they aren't immediately true)
151 UNSERIALIZE_ENUM(_flags);
152 bool wasScheduled = (_flags & Scheduled) && !(_flags & Squashed);
153 _flags &= ~(Squashed | Scheduled);
154
155 if (wasScheduled) {
156 DPRINTF(Config, "rescheduling at %d\n", _when);
157 schedule(_when);
158 }
159}
160
161void
162EventQueue::serialize(ostream &os)
163{
164 std::list<Event *> eventPtrs;
165
166 int numEvents = 0;
167 Event *event = head;
168 while (event) {
169 if (event->getFlags(Event::AutoSerialize)) {
170 eventPtrs.push_back(event);
171 paramOut(os, csprintf("event%d", numEvents++), event->name());
172 }
173 event = event->next;
174 }
175
176 SERIALIZE_SCALAR(numEvents);
177
178 for (std::list<Event *>::iterator it=eventPtrs.begin();
179 it != eventPtrs.end(); ++it) {
180 (*it)->nameOut(os);
181 (*it)->serialize(os);
182 }
183}
184
185void
186EventQueue::unserialize(Checkpoint *cp, const std::string &section)
187{
188 int numEvents;
189 UNSERIALIZE_SCALAR(numEvents);
190
191 std::string eventName;
192 for (int i = 0; i < numEvents; i++) {
193 // get the pointer value associated with the event
194 paramIn(cp, section, csprintf("event%d", i), eventName);
195
196 // create the event based on its pointer value
197 Serializable::create(cp, eventName);
198 }
199}
200
201void
202EventQueue::dump()
203{
204 cprintf("============================================================\n");
205 cprintf("EventQueue Dump (cycle %d)\n", curTick);
206 cprintf("------------------------------------------------------------\n");
207
208 if (empty())
209 cprintf("<No Events>\n");
210 else {
211 Event *event = head;
212 while (event) {
213 event->dump();
214 event = event->next;
215 }
216 }
217
218 cprintf("============================================================\n");
219}
220
221extern "C"
222void
223dumpMainQueue()
224{
225 mainEventQueue.dump();
226}
227
228
229const char *
230Event::description()
231{
232 return "generic";
233}
234
235#if TRACING_ON
236void
237Event::trace(const char *action)
238{
239 // This DPRINTF is unconditional because calls to this function
240 // are protected by an 'if (DTRACE(Event))' in the inlined Event
241 // methods.
242 //
243 // This is just a default implementation for derived classes where
244 // it's not worth doing anything special. If you want to put a
245 // more informative message in the trace, override this method on
246 // the particular subclass where you have the information that
247 // needs to be printed.
248 DPRINTFN("%s event %s @ %d\n", description(), action, when());
249}
250#endif
251
252void
253Event::dump()
254{
255 cprintf("Event (%s)\n", description());
256 cprintf("Flags: %#x\n", _flags);
257#if TRACING_ON
258 cprintf("Created: %d\n", when_created);
259#endif
260 if (scheduled()) {
261#if TRACING_ON
262 cprintf("Scheduled at %d\n", when_scheduled);
263#endif
264 cprintf("Scheduled for %d, priority %d\n", when(), _priority);
265 }
266 else {
267 cprintf("Not Scheduled\n");
268 }
269}