1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include "systemc/core/scheduler.hh"
31
32#include "base/fiber.hh"
33#include "base/logging.hh"
34#include "sim/eventq.hh"
35
36namespace sc_gem5
37{
38
39Scheduler::Scheduler() :
| 1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include "systemc/core/scheduler.hh"
31
32#include "base/fiber.hh"
33#include "base/logging.hh"
34#include "sim/eventq.hh"
35
36namespace sc_gem5
37{
38
39Scheduler::Scheduler() :
|
40 eq(nullptr), _pendingCurr(0), _pendingFuture(0),
41 readyEvent(this, false, ReadyPriority),
| 40 eq(nullptr), readyEvent(this, false, ReadyPriority),
|
42 pauseEvent(this, false, PausePriority),
43 stopEvent(this, false, StopPriority),
44 scMain(nullptr), _started(false), _paused(false), _stopped(false),
45 maxTickEvent(this, false, MaxTickPriority),
46 _numCycles(0), _current(nullptr), initReady(false)
47{}
48
49void
50Scheduler::prepareForInit()
51{
52 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
53 p->finalize();
54 p->popListNode();
55 }
56
57 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
58 p->finalize();
59 p->ready();
60 }
61
62 if (_started)
63 eq->schedule(&maxTickEvent, maxTick);
64
65 initReady = true;
66}
67
68void
69Scheduler::reg(Process *p)
70{
71 if (initReady) {
72 // If we're past initialization, finalize static sensitivity.
73 p->finalize();
74 // Mark the process as ready.
75 p->ready();
76 } else {
77 // Otherwise, record that this process should be initialized once we
78 // get there.
79 initList.pushLast(p);
80 }
81}
82
83void
84Scheduler::dontInitialize(Process *p)
85{
86 if (initReady) {
87 // Pop this process off of the ready list.
88 p->popListNode();
89 } else {
90 // Push this process onto the list of processes which still need
91 // their static sensitivity to be finalized. That implicitly pops it
92 // off the list of processes to be initialized/marked ready.
93 toFinalize.pushLast(p);
94 }
95}
96
97void
98Scheduler::yield()
99{
100 _current = readyList.getNext();
101 if (!_current) {
102 // There are no more processes, so return control to evaluate.
103 Fiber::primaryFiber()->run();
104 } else {
105 _current->popListNode();
106 // Switch to whatever Fiber is supposed to run this process. All
107 // Fibers which aren't running should be parked at this line.
108 _current->fiber()->run();
109 // If the current process needs to be manually started, start it.
110 if (_current && _current->needsStart())
111 _current->run();
112 }
113}
114
115void
116Scheduler::ready(Process *p)
117{
118 // Clump methods together to minimize context switching.
119 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
120 readyList.pushFirst(p);
121 else
122 readyList.pushLast(p);
123
124 scheduleReadyEvent();
125}
126
127void
128Scheduler::requestUpdate(Channel *c)
129{
130 updateList.pushLast(c);
131 scheduleReadyEvent();
132}
133
134void
135Scheduler::scheduleReadyEvent()
136{
137 // Schedule the evaluate and update phases.
138 if (!readyEvent.scheduled()) {
139 panic_if(!eq, "Need to schedule ready, but no event manager.\n");
140 eq->schedule(&readyEvent, eq->getCurTick());
141 }
142}
143
144void
145Scheduler::runReady()
146{
147 bool empty = readyList.empty();
148
149 // The evaluation phase.
150 do {
151 yield();
152 } while (!readyList.empty());
153
154 if (!empty)
155 _numCycles++;
156
157 // The update phase.
158 update();
159
160 // The delta phase will happen naturally through the event queue.
161}
162
163void
164Scheduler::update()
165{
166 Channel *channel = updateList.getNext();
167 while (channel) {
168 channel->popListNode();
169 channel->update();
170 channel = updateList.getNext();
171 }
172}
173
174void
175Scheduler::pause()
176{
177 _paused = true;
178 scMain->run();
179}
180
181void
182Scheduler::stop()
183{
184 _stopped = true;
185 scMain->run();
186}
187
188void
189Scheduler::start(Tick max_tick, bool run_to_time)
190{
191 // We should be running from sc_main. Keep track of that Fiber to return
192 // to later.
193 scMain = Fiber::currentFiber();
194
195 _started = true;
196 _paused = false;
197 _stopped = false;
198
199 maxTick = max_tick;
200
201 if (initReady)
202 eq->schedule(&maxTickEvent, maxTick);
203
204 // Return to gem5 to let it run events, etc.
205 Fiber::primaryFiber()->run();
206
207 if (pauseEvent.scheduled())
208 eq->deschedule(&pauseEvent);
209 if (stopEvent.scheduled())
210 eq->deschedule(&stopEvent);
211 if (maxTickEvent.scheduled())
212 eq->deschedule(&maxTickEvent);
213}
214
215void
216Scheduler::schedulePause()
217{
218 if (pauseEvent.scheduled())
219 return;
220
221 eq->schedule(&pauseEvent, eq->getCurTick());
222}
223
224void
225Scheduler::scheduleStop(bool finish_delta)
226{
227 if (stopEvent.scheduled())
228 return;
229
230 if (!finish_delta) {
231 // If we're not supposed to finish the delta cycle, flush the list
232 // of ready processes and scheduled updates.
233 Process *p;
234 while ((p = readyList.getNext()))
235 p->popListNode();
236 Channel *c;
237 while ((c = updateList.getNext()))
238 c->popListNode();
239 }
240 eq->schedule(&stopEvent, eq->getCurTick());
241}
242
243Scheduler scheduler;
244
245} // namespace sc_gem5
| 41 pauseEvent(this, false, PausePriority),
42 stopEvent(this, false, StopPriority),
43 scMain(nullptr), _started(false), _paused(false), _stopped(false),
44 maxTickEvent(this, false, MaxTickPriority),
45 _numCycles(0), _current(nullptr), initReady(false)
46{}
47
48void
49Scheduler::prepareForInit()
50{
51 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
52 p->finalize();
53 p->popListNode();
54 }
55
56 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
57 p->finalize();
58 p->ready();
59 }
60
61 if (_started)
62 eq->schedule(&maxTickEvent, maxTick);
63
64 initReady = true;
65}
66
67void
68Scheduler::reg(Process *p)
69{
70 if (initReady) {
71 // If we're past initialization, finalize static sensitivity.
72 p->finalize();
73 // Mark the process as ready.
74 p->ready();
75 } else {
76 // Otherwise, record that this process should be initialized once we
77 // get there.
78 initList.pushLast(p);
79 }
80}
81
82void
83Scheduler::dontInitialize(Process *p)
84{
85 if (initReady) {
86 // Pop this process off of the ready list.
87 p->popListNode();
88 } else {
89 // Push this process onto the list of processes which still need
90 // their static sensitivity to be finalized. That implicitly pops it
91 // off the list of processes to be initialized/marked ready.
92 toFinalize.pushLast(p);
93 }
94}
95
96void
97Scheduler::yield()
98{
99 _current = readyList.getNext();
100 if (!_current) {
101 // There are no more processes, so return control to evaluate.
102 Fiber::primaryFiber()->run();
103 } else {
104 _current->popListNode();
105 // Switch to whatever Fiber is supposed to run this process. All
106 // Fibers which aren't running should be parked at this line.
107 _current->fiber()->run();
108 // If the current process needs to be manually started, start it.
109 if (_current && _current->needsStart())
110 _current->run();
111 }
112}
113
114void
115Scheduler::ready(Process *p)
116{
117 // Clump methods together to minimize context switching.
118 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
119 readyList.pushFirst(p);
120 else
121 readyList.pushLast(p);
122
123 scheduleReadyEvent();
124}
125
126void
127Scheduler::requestUpdate(Channel *c)
128{
129 updateList.pushLast(c);
130 scheduleReadyEvent();
131}
132
133void
134Scheduler::scheduleReadyEvent()
135{
136 // Schedule the evaluate and update phases.
137 if (!readyEvent.scheduled()) {
138 panic_if(!eq, "Need to schedule ready, but no event manager.\n");
139 eq->schedule(&readyEvent, eq->getCurTick());
140 }
141}
142
143void
144Scheduler::runReady()
145{
146 bool empty = readyList.empty();
147
148 // The evaluation phase.
149 do {
150 yield();
151 } while (!readyList.empty());
152
153 if (!empty)
154 _numCycles++;
155
156 // The update phase.
157 update();
158
159 // The delta phase will happen naturally through the event queue.
160}
161
162void
163Scheduler::update()
164{
165 Channel *channel = updateList.getNext();
166 while (channel) {
167 channel->popListNode();
168 channel->update();
169 channel = updateList.getNext();
170 }
171}
172
173void
174Scheduler::pause()
175{
176 _paused = true;
177 scMain->run();
178}
179
180void
181Scheduler::stop()
182{
183 _stopped = true;
184 scMain->run();
185}
186
187void
188Scheduler::start(Tick max_tick, bool run_to_time)
189{
190 // We should be running from sc_main. Keep track of that Fiber to return
191 // to later.
192 scMain = Fiber::currentFiber();
193
194 _started = true;
195 _paused = false;
196 _stopped = false;
197
198 maxTick = max_tick;
199
200 if (initReady)
201 eq->schedule(&maxTickEvent, maxTick);
202
203 // Return to gem5 to let it run events, etc.
204 Fiber::primaryFiber()->run();
205
206 if (pauseEvent.scheduled())
207 eq->deschedule(&pauseEvent);
208 if (stopEvent.scheduled())
209 eq->deschedule(&stopEvent);
210 if (maxTickEvent.scheduled())
211 eq->deschedule(&maxTickEvent);
212}
213
214void
215Scheduler::schedulePause()
216{
217 if (pauseEvent.scheduled())
218 return;
219
220 eq->schedule(&pauseEvent, eq->getCurTick());
221}
222
223void
224Scheduler::scheduleStop(bool finish_delta)
225{
226 if (stopEvent.scheduled())
227 return;
228
229 if (!finish_delta) {
230 // If we're not supposed to finish the delta cycle, flush the list
231 // of ready processes and scheduled updates.
232 Process *p;
233 while ((p = readyList.getNext()))
234 p->popListNode();
235 Channel *c;
236 while ((c = updateList.getNext()))
237 c->popListNode();
238 }
239 eq->schedule(&stopEvent, eq->getCurTick());
240}
241
242Scheduler scheduler;
243
244} // namespace sc_gem5
|