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),
|
50 runOnce(false)
51{}
52
53Scheduler::~Scheduler()
54{
55 // Clear out everything that belongs to us to make sure nobody tries to
56 // clear themselves out after the scheduler goes away.
57 clear();
58}
59
60void
61Scheduler::clear()
62{
63 // Delta notifications.
64 for (auto &e: deltas)
65 e->deschedule();
66 deltas.clear();
67
68 // Timed notifications.
69 for (auto &tsp: timeSlots) {
70 TimeSlot *&ts = tsp.second;
71 for (auto &e: ts->events)
72 e->deschedule();
73 deschedule(ts);
74 }
75 timeSlots.clear();
76
77 // gem5 events.
78 if (readyEvent.scheduled())
79 deschedule(&readyEvent);
80 if (pauseEvent.scheduled())
81 deschedule(&pauseEvent);
82 if (stopEvent.scheduled())
83 deschedule(&stopEvent);
84 if (starvationEvent.scheduled())
85 deschedule(&starvationEvent);
86 if (maxTickEvent.scheduled())
87 deschedule(&maxTickEvent);
88
89 Process *p;
90 while ((p = toFinalize.getNext()))
91 p->popListNode();
92 while ((p = initList.getNext()))
93 p->popListNode();
94 while ((p = readyList.getNext()))
95 p->popListNode();
96
97 Channel *c;
98 while ((c = updateList.getNext()))
99 c->popListNode();
100}
101
102void
103Scheduler::initPhase()
104{
105 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
106 p->finalize();
107 p->popListNode();
108 }
109
110 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
111 p->finalize();
112 p->popListNode();
113 p->ready();
114 }
115
116 update();
117
118 for (auto &e: deltas)
119 e->run();
120 deltas.clear();
121
122 for (auto ets: eventsToSchedule)
123 eq->schedule(ets.first, ets.second);
124 eventsToSchedule.clear();
125
126 if (_started) {
127 if (!runToTime && starved())
128 scheduleStarvationEvent();
129 kernel->status(::sc_core::SC_RUNNING);
130 }
131
132 initDone = true;
133}
134
135void
136Scheduler::reg(Process *p)
137{
138 if (initDone) {
139 // If we're past initialization, finalize static sensitivity.
140 p->finalize();
141 // Mark the process as ready.
142 p->ready();
143 } else {
144 // Otherwise, record that this process should be initialized once we
145 // get there.
146 initList.pushLast(p);
147 }
148}
149
150void
151Scheduler::dontInitialize(Process *p)
152{
153 if (initDone) {
154 // Pop this process off of the ready list.
155 p->popListNode();
156 } else {
157 // Push this process onto the list of processes which still need
158 // their static sensitivity to be finalized. That implicitly pops it
159 // off the list of processes to be initialized/marked ready.
160 toFinalize.pushLast(p);
161 }
162}
163
164void
165Scheduler::yield()
166{
167 _current = readyList.getNext();
168 if (!_current) {
169 // There are no more processes, so return control to evaluate.
170 Fiber::primaryFiber()->run();
171 } else {
172 _current->popListNode();
173 // Switch to whatever Fiber is supposed to run this process. All
174 // Fibers which aren't running should be parked at this line.
175 _current->fiber()->run();
176 // If the current process needs to be manually started, start it.
177 if (_current && _current->needsStart()) {
178 _current->needsStart(false);
179 _current->run();
180 }
181 }
182 if (_current && _current->excWrapper) {
183 // Make sure this isn't a method process.
184 assert(!_current->needsStart());
185 auto ew = _current->excWrapper;
186 _current->excWrapper = nullptr;
187 ew->throw_it();
188 }
189}
190
191void
192Scheduler::ready(Process *p)
193{
194 // Clump methods together to minimize context switching.
195 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
196 readyList.pushFirst(p);
197 else
198 readyList.pushLast(p);
199
200 scheduleReadyEvent();
201}
202
203void
204Scheduler::resume(Process *p)
205{
206 if (initDone)
207 ready(p);
208 else
209 initList.pushLast(p);
210}
211
212bool
213Scheduler::suspend(Process *p)
214{
215 if (initDone) {
216 // After initialization, the only list we can be on is the ready list.
217 bool was_ready = (p->nextListNode != nullptr);
218 p->popListNode();
219 return was_ready;
220 } else {
221 bool was_ready = false;
222 // Check the ready list to see if we find this process.
223 ListNode *n = readyList.nextListNode;
224 while (n != &readyList) {
225 if (n == p) {
226 was_ready = true;
227 break;
228 }
229 }
230 if (was_ready)
231 toFinalize.pushLast(p);
232 return was_ready;
233 }
234}
235
236void
237Scheduler::requestUpdate(Channel *c)
238{
239 updateList.pushLast(c);
240 scheduleReadyEvent();
241}
242
243void
244Scheduler::scheduleReadyEvent()
245{
246 // Schedule the evaluate and update phases.
247 if (!readyEvent.scheduled()) {
248 schedule(&readyEvent);
249 if (starvationEvent.scheduled())
250 deschedule(&starvationEvent);
251 }
252}
253
254void
255Scheduler::scheduleStarvationEvent()
256{
257 if (!starvationEvent.scheduled()) {
258 schedule(&starvationEvent);
259 if (readyEvent.scheduled())
260 deschedule(&readyEvent);
261 }
262}
263
264void
265Scheduler::runReady()
266{
267 bool empty = readyList.empty();
| 50 runOnce(false)
51{}
52
53Scheduler::~Scheduler()
54{
55 // Clear out everything that belongs to us to make sure nobody tries to
56 // clear themselves out after the scheduler goes away.
57 clear();
58}
59
60void
61Scheduler::clear()
62{
63 // Delta notifications.
64 for (auto &e: deltas)
65 e->deschedule();
66 deltas.clear();
67
68 // Timed notifications.
69 for (auto &tsp: timeSlots) {
70 TimeSlot *&ts = tsp.second;
71 for (auto &e: ts->events)
72 e->deschedule();
73 deschedule(ts);
74 }
75 timeSlots.clear();
76
77 // gem5 events.
78 if (readyEvent.scheduled())
79 deschedule(&readyEvent);
80 if (pauseEvent.scheduled())
81 deschedule(&pauseEvent);
82 if (stopEvent.scheduled())
83 deschedule(&stopEvent);
84 if (starvationEvent.scheduled())
85 deschedule(&starvationEvent);
86 if (maxTickEvent.scheduled())
87 deschedule(&maxTickEvent);
88
89 Process *p;
90 while ((p = toFinalize.getNext()))
91 p->popListNode();
92 while ((p = initList.getNext()))
93 p->popListNode();
94 while ((p = readyList.getNext()))
95 p->popListNode();
96
97 Channel *c;
98 while ((c = updateList.getNext()))
99 c->popListNode();
100}
101
102void
103Scheduler::initPhase()
104{
105 for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) {
106 p->finalize();
107 p->popListNode();
108 }
109
110 for (Process *p = initList.getNext(); p; p = initList.getNext()) {
111 p->finalize();
112 p->popListNode();
113 p->ready();
114 }
115
116 update();
117
118 for (auto &e: deltas)
119 e->run();
120 deltas.clear();
121
122 for (auto ets: eventsToSchedule)
123 eq->schedule(ets.first, ets.second);
124 eventsToSchedule.clear();
125
126 if (_started) {
127 if (!runToTime && starved())
128 scheduleStarvationEvent();
129 kernel->status(::sc_core::SC_RUNNING);
130 }
131
132 initDone = true;
133}
134
135void
136Scheduler::reg(Process *p)
137{
138 if (initDone) {
139 // If we're past initialization, finalize static sensitivity.
140 p->finalize();
141 // Mark the process as ready.
142 p->ready();
143 } else {
144 // Otherwise, record that this process should be initialized once we
145 // get there.
146 initList.pushLast(p);
147 }
148}
149
150void
151Scheduler::dontInitialize(Process *p)
152{
153 if (initDone) {
154 // Pop this process off of the ready list.
155 p->popListNode();
156 } else {
157 // Push this process onto the list of processes which still need
158 // their static sensitivity to be finalized. That implicitly pops it
159 // off the list of processes to be initialized/marked ready.
160 toFinalize.pushLast(p);
161 }
162}
163
164void
165Scheduler::yield()
166{
167 _current = readyList.getNext();
168 if (!_current) {
169 // There are no more processes, so return control to evaluate.
170 Fiber::primaryFiber()->run();
171 } else {
172 _current->popListNode();
173 // Switch to whatever Fiber is supposed to run this process. All
174 // Fibers which aren't running should be parked at this line.
175 _current->fiber()->run();
176 // If the current process needs to be manually started, start it.
177 if (_current && _current->needsStart()) {
178 _current->needsStart(false);
179 _current->run();
180 }
181 }
182 if (_current && _current->excWrapper) {
183 // Make sure this isn't a method process.
184 assert(!_current->needsStart());
185 auto ew = _current->excWrapper;
186 _current->excWrapper = nullptr;
187 ew->throw_it();
188 }
189}
190
191void
192Scheduler::ready(Process *p)
193{
194 // Clump methods together to minimize context switching.
195 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
196 readyList.pushFirst(p);
197 else
198 readyList.pushLast(p);
199
200 scheduleReadyEvent();
201}
202
203void
204Scheduler::resume(Process *p)
205{
206 if (initDone)
207 ready(p);
208 else
209 initList.pushLast(p);
210}
211
212bool
213Scheduler::suspend(Process *p)
214{
215 if (initDone) {
216 // After initialization, the only list we can be on is the ready list.
217 bool was_ready = (p->nextListNode != nullptr);
218 p->popListNode();
219 return was_ready;
220 } else {
221 bool was_ready = false;
222 // Check the ready list to see if we find this process.
223 ListNode *n = readyList.nextListNode;
224 while (n != &readyList) {
225 if (n == p) {
226 was_ready = true;
227 break;
228 }
229 }
230 if (was_ready)
231 toFinalize.pushLast(p);
232 return was_ready;
233 }
234}
235
236void
237Scheduler::requestUpdate(Channel *c)
238{
239 updateList.pushLast(c);
240 scheduleReadyEvent();
241}
242
243void
244Scheduler::scheduleReadyEvent()
245{
246 // Schedule the evaluate and update phases.
247 if (!readyEvent.scheduled()) {
248 schedule(&readyEvent);
249 if (starvationEvent.scheduled())
250 deschedule(&starvationEvent);
251 }
252}
253
254void
255Scheduler::scheduleStarvationEvent()
256{
257 if (!starvationEvent.scheduled()) {
258 schedule(&starvationEvent);
259 if (readyEvent.scheduled())
260 deschedule(&readyEvent);
261 }
262}
263
264void
265Scheduler::runReady()
266{
267 bool empty = readyList.empty();
|