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#include "systemc/core/kernel.hh"
36#include "systemc/ext/core/sc_main.hh"
37
38namespace sc_gem5
39{
40
41Scheduler::Scheduler() :
42 eq(nullptr), readyEvent(this, false, ReadyPriority),
43 pauseEvent(this, false, PausePriority),
44 stopEvent(this, false, StopPriority),
45 scMain(nullptr),
46 starvationEvent(this, false, StarvationPriority),
47 _started(false), _paused(false), _stopped(false),
48 maxTickEvent(this, false, MaxTickPriority),
| 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#include "systemc/core/kernel.hh"
36#include "systemc/ext/core/sc_main.hh"
37
38namespace sc_gem5
39{
40
41Scheduler::Scheduler() :
42 eq(nullptr), readyEvent(this, false, ReadyPriority),
43 pauseEvent(this, false, PausePriority),
44 stopEvent(this, false, StopPriority),
45 scMain(nullptr),
46 starvationEvent(this, false, StarvationPriority),
47 _started(false), _paused(false), _stopped(false),
48 maxTickEvent(this, false, MaxTickPriority),
|
49 _numCycles(0), _current(nullptr), initReady(false),
| 49 _numCycles(0), _current(nullptr), initDone(false),
|
50 runOnce(false)
51{}
52
53void
| 50 runOnce(false)
51{}
52
53void
|
54Scheduler::prepareForInit()
| 54Scheduler::initPhase()
|
55{
56 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
57 p->finalize();
58 p->popListNode();
59 }
60
61 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
62 p->finalize();
63 p->popListNode();
64 p->ready();
65 }
66
| 55{
56 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
57 p->finalize();
58 p->popListNode();
59 }
60
61 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
62 p->finalize();
63 p->popListNode();
64 p->ready();
65 }
66
|
| 67 update();
68
69 for (auto &e: deltas)
70 e->run();
71 deltas.clear();
72
|
67 for (auto ets: eventsToSchedule)
68 eq->schedule(ets.first, ets.second);
69 eventsToSchedule.clear();
70
71 if (_started)
72 eq->schedule(&maxTickEvent, maxTick);
73
| 73 for (auto ets: eventsToSchedule)
74 eq->schedule(ets.first, ets.second);
75 eventsToSchedule.clear();
76
77 if (_started)
78 eq->schedule(&maxTickEvent, maxTick);
79
|
74 initReady = true;
| 80 initDone = true;
|
75}
76
77void
78Scheduler::reg(Process *p)
79{
| 81}
82
83void
84Scheduler::reg(Process *p)
85{
|
80 if (initReady) {
| 86 if (initDone) {
|
81 // If we're past initialization, finalize static sensitivity.
82 p->finalize();
83 // Mark the process as ready.
84 p->ready();
85 } else {
86 // Otherwise, record that this process should be initialized once we
87 // get there.
88 initList.pushLast(p);
89 }
90}
91
92void
93Scheduler::dontInitialize(Process *p)
94{
| 87 // If we're past initialization, finalize static sensitivity.
88 p->finalize();
89 // Mark the process as ready.
90 p->ready();
91 } else {
92 // Otherwise, record that this process should be initialized once we
93 // get there.
94 initList.pushLast(p);
95 }
96}
97
98void
99Scheduler::dontInitialize(Process *p)
100{
|
95 if (initReady) {
| 101 if (initDone) {
|
96 // Pop this process off of the ready list.
97 p->popListNode();
98 } else {
99 // Push this process onto the list of processes which still need
100 // their static sensitivity to be finalized. That implicitly pops it
101 // off the list of processes to be initialized/marked ready.
102 toFinalize.pushLast(p);
103 }
104}
105
106void
107Scheduler::yield()
108{
109 _current = readyList.getNext();
110 if (!_current) {
111 // There are no more processes, so return control to evaluate.
112 Fiber::primaryFiber()->run();
113 } else {
114 _current->popListNode();
115 // Switch to whatever Fiber is supposed to run this process. All
116 // Fibers which aren't running should be parked at this line.
117 _current->fiber()->run();
118 // If the current process needs to be manually started, start it.
119 if (_current && _current->needsStart())
120 _current->run();
121 }
122 if (_current && _current->excWrapper) {
123 // Make sure this isn't a method process.
124 assert(!_current->needsStart());
125 auto ew = _current->excWrapper;
126 _current->excWrapper = nullptr;
127 ew->throw_it();
128 }
129}
130
131void
132Scheduler::ready(Process *p)
133{
134 // Clump methods together to minimize context switching.
135 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
136 readyList.pushFirst(p);
137 else
138 readyList.pushLast(p);
139
140 scheduleReadyEvent();
141}
142
143void
144Scheduler::requestUpdate(Channel *c)
145{
146 updateList.pushLast(c);
147 if (eq)
148 scheduleReadyEvent();
149}
150
151void
152Scheduler::scheduleReadyEvent()
153{
154 // Schedule the evaluate and update phases.
155 if (!readyEvent.scheduled()) {
156 panic_if(!eq, "Need to schedule ready, but no event manager.\n");
157 eq->schedule(&readyEvent, eq->getCurTick());
158 if (starvationEvent.scheduled())
159 eq->deschedule(&starvationEvent);
160 }
161}
162
163void
164Scheduler::scheduleStarvationEvent()
165{
166 if (!starvationEvent.scheduled()) {
167 panic_if(!eq, "Need to schedule starvation event, "
168 "but no event manager.\n");
169 eq->schedule(&starvationEvent, eq->getCurTick());
170 if (readyEvent.scheduled())
171 eq->deschedule(&readyEvent);
172 }
173}
174
175void
176Scheduler::runReady()
177{
178 bool empty = readyList.empty();
179
180 // The evaluation phase.
181 do {
182 yield();
183 } while (!readyList.empty());
184
185 if (!empty)
186 _numCycles++;
187
188 // The update phase.
189 update();
190
191 if (starved() && !runToTime)
192 scheduleStarvationEvent();
193
194 // The delta phase.
195 for (auto &e: deltas)
196 e->run();
197 deltas.clear();
198
199 if (runOnce)
200 schedulePause();
201}
202
203void
204Scheduler::update()
205{
206 Channel *channel = updateList.getNext();
207 while (channel) {
208 channel->popListNode();
209 channel->update();
210 channel = updateList.getNext();
211 }
212}
213
214void
215Scheduler::pause()
216{
217 _paused = true;
218 kernel->status(::sc_core::SC_PAUSED);
219 runOnce = false;
220 scMain->run();
221}
222
223void
224Scheduler::stop()
225{
226 _stopped = true;
227 kernel->stop();
228 runOnce = false;
229 scMain->run();
230}
231
232void
233Scheduler::start(Tick max_tick, bool run_to_time)
234{
235 // We should be running from sc_main. Keep track of that Fiber to return
236 // to later.
237 scMain = Fiber::currentFiber();
238
239 _started = true;
240 _paused = false;
241 _stopped = false;
242 runToTime = run_to_time;
243
244 maxTick = max_tick;
245
246 if (starved() && !runToTime)
247 return;
248
| 102 // Pop this process off of the ready list.
103 p->popListNode();
104 } else {
105 // Push this process onto the list of processes which still need
106 // their static sensitivity to be finalized. That implicitly pops it
107 // off the list of processes to be initialized/marked ready.
108 toFinalize.pushLast(p);
109 }
110}
111
112void
113Scheduler::yield()
114{
115 _current = readyList.getNext();
116 if (!_current) {
117 // There are no more processes, so return control to evaluate.
118 Fiber::primaryFiber()->run();
119 } else {
120 _current->popListNode();
121 // Switch to whatever Fiber is supposed to run this process. All
122 // Fibers which aren't running should be parked at this line.
123 _current->fiber()->run();
124 // If the current process needs to be manually started, start it.
125 if (_current && _current->needsStart())
126 _current->run();
127 }
128 if (_current && _current->excWrapper) {
129 // Make sure this isn't a method process.
130 assert(!_current->needsStart());
131 auto ew = _current->excWrapper;
132 _current->excWrapper = nullptr;
133 ew->throw_it();
134 }
135}
136
137void
138Scheduler::ready(Process *p)
139{
140 // Clump methods together to minimize context switching.
141 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
142 readyList.pushFirst(p);
143 else
144 readyList.pushLast(p);
145
146 scheduleReadyEvent();
147}
148
149void
150Scheduler::requestUpdate(Channel *c)
151{
152 updateList.pushLast(c);
153 if (eq)
154 scheduleReadyEvent();
155}
156
157void
158Scheduler::scheduleReadyEvent()
159{
160 // Schedule the evaluate and update phases.
161 if (!readyEvent.scheduled()) {
162 panic_if(!eq, "Need to schedule ready, but no event manager.\n");
163 eq->schedule(&readyEvent, eq->getCurTick());
164 if (starvationEvent.scheduled())
165 eq->deschedule(&starvationEvent);
166 }
167}
168
169void
170Scheduler::scheduleStarvationEvent()
171{
172 if (!starvationEvent.scheduled()) {
173 panic_if(!eq, "Need to schedule starvation event, "
174 "but no event manager.\n");
175 eq->schedule(&starvationEvent, eq->getCurTick());
176 if (readyEvent.scheduled())
177 eq->deschedule(&readyEvent);
178 }
179}
180
181void
182Scheduler::runReady()
183{
184 bool empty = readyList.empty();
185
186 // The evaluation phase.
187 do {
188 yield();
189 } while (!readyList.empty());
190
191 if (!empty)
192 _numCycles++;
193
194 // The update phase.
195 update();
196
197 if (starved() && !runToTime)
198 scheduleStarvationEvent();
199
200 // The delta phase.
201 for (auto &e: deltas)
202 e->run();
203 deltas.clear();
204
205 if (runOnce)
206 schedulePause();
207}
208
209void
210Scheduler::update()
211{
212 Channel *channel = updateList.getNext();
213 while (channel) {
214 channel->popListNode();
215 channel->update();
216 channel = updateList.getNext();
217 }
218}
219
220void
221Scheduler::pause()
222{
223 _paused = true;
224 kernel->status(::sc_core::SC_PAUSED);
225 runOnce = false;
226 scMain->run();
227}
228
229void
230Scheduler::stop()
231{
232 _stopped = true;
233 kernel->stop();
234 runOnce = false;
235 scMain->run();
236}
237
238void
239Scheduler::start(Tick max_tick, bool run_to_time)
240{
241 // We should be running from sc_main. Keep track of that Fiber to return
242 // to later.
243 scMain = Fiber::currentFiber();
244
245 _started = true;
246 _paused = false;
247 _stopped = false;
248 runToTime = run_to_time;
249
250 maxTick = max_tick;
251
252 if (starved() && !runToTime)
253 return;
254
|
249 if (initReady) {
| 255 if (initDone) {
|
250 kernel->status(::sc_core::SC_RUNNING);
251 eq->schedule(&maxTickEvent, maxTick);
252 }
253
254 // Return to gem5 to let it run events, etc.
255 Fiber::primaryFiber()->run();
256
257 if (pauseEvent.scheduled())
258 eq->deschedule(&pauseEvent);
259 if (stopEvent.scheduled())
260 eq->deschedule(&stopEvent);
261 if (maxTickEvent.scheduled())
262 eq->deschedule(&maxTickEvent);
263 if (starvationEvent.scheduled())
264 eq->deschedule(&starvationEvent);
265}
266
267void
268Scheduler::oneCycle()
269{
270 runOnce = true;
271 start(::MaxTick, false);
272}
273
274void
275Scheduler::schedulePause()
276{
277 if (pauseEvent.scheduled())
278 return;
279
280 eq->schedule(&pauseEvent, eq->getCurTick());
281}
282
283void
284Scheduler::scheduleStop(bool finish_delta)
285{
286 if (stopEvent.scheduled())
287 return;
288
289 if (!finish_delta) {
290 // If we're not supposed to finish the delta cycle, flush the list
291 // of ready processes, scheduled updates, and delta notifications.
292 Process *p;
293 while ((p = readyList.getNext()))
294 p->popListNode();
295 Channel *c;
296 while ((c = updateList.getNext()))
297 c->popListNode();
298 for (auto &e: deltas)
299 e->deschedule();
300 deltas.clear();
301 }
302 eq->schedule(&stopEvent, eq->getCurTick());
303}
304
305Scheduler scheduler;
306
307} // namespace sc_gem5
| 256 kernel->status(::sc_core::SC_RUNNING);
257 eq->schedule(&maxTickEvent, maxTick);
258 }
259
260 // Return to gem5 to let it run events, etc.
261 Fiber::primaryFiber()->run();
262
263 if (pauseEvent.scheduled())
264 eq->deschedule(&pauseEvent);
265 if (stopEvent.scheduled())
266 eq->deschedule(&stopEvent);
267 if (maxTickEvent.scheduled())
268 eq->deschedule(&maxTickEvent);
269 if (starvationEvent.scheduled())
270 eq->deschedule(&starvationEvent);
271}
272
273void
274Scheduler::oneCycle()
275{
276 runOnce = true;
277 start(::MaxTick, false);
278}
279
280void
281Scheduler::schedulePause()
282{
283 if (pauseEvent.scheduled())
284 return;
285
286 eq->schedule(&pauseEvent, eq->getCurTick());
287}
288
289void
290Scheduler::scheduleStop(bool finish_delta)
291{
292 if (stopEvent.scheduled())
293 return;
294
295 if (!finish_delta) {
296 // If we're not supposed to finish the delta cycle, flush the list
297 // of ready processes, scheduled updates, and delta notifications.
298 Process *p;
299 while ((p = readyList.getNext()))
300 p->popListNode();
301 Channel *c;
302 while ((c = updateList.getNext()))
303 c->popListNode();
304 for (auto &e: deltas)
305 e->deschedule();
306 deltas.clear();
307 }
308 eq->schedule(&stopEvent, eq->getCurTick());
309}
310
311Scheduler scheduler;
312
313} // namespace sc_gem5
|