scheduler.cc (12953:ddfd5e4643a9) scheduler.cc (12954:8ea3a185354c)
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

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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"
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

--- 16 unchanged lines hidden (view full) ---

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"
33
34namespace sc_gem5
35{
36
35
36namespace sc_gem5
37{
38
37Scheduler::Scheduler() : _numCycles(0), _current(nullptr) {}
39Scheduler::Scheduler() :
40 eq(nullptr), readyEvent(this, false, EventBase::Default_Pri + 1),
41 _numCycles(0), _current(nullptr)
42{}
38
39void
43
44void
40Scheduler::initialize()
45Scheduler::initToReady()
41{
46{
42 update();
43
44 while (!initList.empty())
45 ready(initList.getNext());
47 while (!initList.empty())
48 ready(initList.getNext());
46
47 delta();
48}
49
50void
49}
50
51void
51Scheduler::runCycles()
52{
53 while (!readyList.empty()) {
54 evaluate();
55 update();
56 delta();
57 }
58}
59
60void
61Scheduler::yield()
62{
63 _current = readyList.getNext();
64 if (!_current) {
65 // There are no more processes, so return control to evaluate.
66 Fiber::primaryFiber()->run();
67 } else {
68 _current->popListNode();
69 // Switch to whatever Fiber is supposed to run this process. All
70 // Fibers which aren't running should be parked at this line.
71 _current->fiber()->run();
72 // If the current process hasn't been started yet, start it. This
73 // should always be true for methods, but may not be true for threads.
74 if (_current && !_current->running())
75 _current->run();
76 }
77}
78
79void
52Scheduler::yield()
53{
54 _current = readyList.getNext();
55 if (!_current) {
56 // There are no more processes, so return control to evaluate.
57 Fiber::primaryFiber()->run();
58 } else {
59 _current->popListNode();
60 // Switch to whatever Fiber is supposed to run this process. All
61 // Fibers which aren't running should be parked at this line.
62 _current->fiber()->run();
63 // If the current process hasn't been started yet, start it. This
64 // should always be true for methods, but may not be true for threads.
65 if (_current && !_current->running())
66 _current->run();
67 }
68}
69
70void
80Scheduler::evaluate()
71Scheduler::ready(Process *p)
81{
72{
82 if (!readyList.empty())
83 _numCycles++;
73 // Clump methods together to minimize context switching.
74 if (p->procKind() == ::sc_core::SC_METHOD_PROC_)
75 readyList.pushFirst(p);
76 else
77 readyList.pushLast(p);
84
78
85 do {
86 yield();
87 } while (!readyList.empty());
79 scheduleReadyEvent();
88}
89
90void
80}
81
82void
91Scheduler::update()
83Scheduler::requestUpdate(Channel *c)
92{
84{
85 updateList.pushLast(c);
86 scheduleReadyEvent();
93}
94
95void
87}
88
89void
96Scheduler::delta()
90Scheduler::scheduleReadyEvent()
97{
91{
92 // Schedule the evaluate and update phases.
93 if (!readyEvent.scheduled()) {
94 panic_if(!eq, "Need to schedule ready, but no event manager.\n");
95 eq->schedule(&readyEvent, eq->getCurTick());
96 }
98}
99
97}
98
99void
100Scheduler::runReady()
101{
102 bool empty = readyList.empty();
103
104 // The evaluation phase.
105 do {
106 yield();
107 } while (!readyList.empty());
108
109 if (!empty)
110 _numCycles++;
111
112 // The update phase.
113 update();
114
115 // The delta phase will happen naturally through the event queue.
116}
117
118void
119Scheduler::update()
120{
121 Channel *channel = updateList.getNext();
122 while (channel) {
123 channel->popListNode();
124 channel->update();
125 channel = updateList.getNext();
126 }
127}
128
100Scheduler scheduler;
101
102} // namespace sc_gem5
129Scheduler scheduler;
130
131} // namespace sc_gem5