1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * Copyright (c) 2011 Advanced Micro Devices, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Nathan Binkert
30 * Steve Reinhardt
31 * Gabe Black
32 */
33
| 1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * Copyright (c) 2011 Advanced Micro Devices, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Nathan Binkert
30 * Steve Reinhardt
31 * Gabe Black
32 */
33
|
35#include "base/trace.hh"
36#include "config/the_isa.hh"
37#include "debug/TimeSync.hh"
38#include "sim/eventq_impl.hh"
39#include "sim/full_system.hh"
40#include "sim/root.hh"
41
42Root *Root::_root = NULL;
43
44/*
45 * This function is called periodically by an event in M5 and ensures that
46 * at least as much real time has passed between invocations as simulated time.
47 * If not, the function either sleeps, or if the difference is small enough
48 * spin waits.
49 */
50void
51Root::timeSync()
52{
53 Time cur_time, diff, period = timeSyncPeriod();
54
55 do {
56 cur_time.setTimer();
57 diff = cur_time - lastTime;
58 Time remainder = period - diff;
59 if (diff < period && remainder > _spinThreshold) {
60 DPRINTF(TimeSync, "Sleeping to sync with real time.\n");
61 // Sleep until the end of the period, or until a signal.
62 sleep(remainder);
63 // Refresh the current time.
64 cur_time.setTimer();
65 }
66 } while (diff < period);
67 lastTime = cur_time;
68 schedule(&syncEvent, curTick() + _periodTick);
69}
70
71void
72Root::timeSyncEnable(bool en)
73{
74 if (en == _enabled)
75 return;
76 _enabled = en;
77 if (_enabled) {
78 // Get event going.
79 Tick periods = ((curTick() + _periodTick - 1) / _periodTick);
80 Tick nextPeriod = periods * _periodTick;
81 schedule(&syncEvent, nextPeriod);
82 } else {
83 // Stop event.
84 deschedule(&syncEvent);
85 }
86}
87
88/// Configure the period for time sync events.
89void
90Root::timeSyncPeriod(Time newPeriod)
91{
92 bool en = timeSyncEnabled();
93 _period = newPeriod;
94 _periodTick = _period.getTick();
95 timeSyncEnable(en);
96}
97
98/// Set the threshold for time remaining to spin wait.
99void
100Root::timeSyncSpinThreshold(Time newThreshold)
101{
102 bool en = timeSyncEnabled();
103 _spinThreshold = newThreshold;
104 timeSyncEnable(en);
105}
106
107Root::Root(RootParams *p)
108 : SimObject(p), _enabled(false), _periodTick(p->time_sync_period),
109 syncEvent([this]{ timeSync(); }, name())
110{
111 _period.setTick(p->time_sync_period);
112 _spinThreshold.setTick(p->time_sync_spin_threshold);
113
114 assert(_root == NULL);
115 _root = this;
116 lastTime.setTimer();
117
118 simQuantum = p->sim_quantum;
119}
120
121void
122Root::startup()
123{
124 timeSyncEnable(params()->time_sync_enable);
125}
126
127void
128Root::serialize(CheckpointOut &cp) const
129{
130 SERIALIZE_SCALAR(FullSystem);
131 std::string isa = THE_ISA_STR;
132 SERIALIZE_SCALAR(isa);
133}
134
135
136bool FullSystem;
137unsigned int FullSystemInt;
138
139Root *
140RootParams::create()
141{
142 static bool created = false;
143 if (created)
144 panic("only one root object allowed!");
145
146 created = true;
147
148 FullSystem = full_system;
149 FullSystemInt = full_system ? 1 : 0;
150
151 return new Root(this);
152}
| 35#include "base/trace.hh"
36#include "config/the_isa.hh"
37#include "debug/TimeSync.hh"
38#include "sim/eventq_impl.hh"
39#include "sim/full_system.hh"
40#include "sim/root.hh"
41
42Root *Root::_root = NULL;
43
44/*
45 * This function is called periodically by an event in M5 and ensures that
46 * at least as much real time has passed between invocations as simulated time.
47 * If not, the function either sleeps, or if the difference is small enough
48 * spin waits.
49 */
50void
51Root::timeSync()
52{
53 Time cur_time, diff, period = timeSyncPeriod();
54
55 do {
56 cur_time.setTimer();
57 diff = cur_time - lastTime;
58 Time remainder = period - diff;
59 if (diff < period && remainder > _spinThreshold) {
60 DPRINTF(TimeSync, "Sleeping to sync with real time.\n");
61 // Sleep until the end of the period, or until a signal.
62 sleep(remainder);
63 // Refresh the current time.
64 cur_time.setTimer();
65 }
66 } while (diff < period);
67 lastTime = cur_time;
68 schedule(&syncEvent, curTick() + _periodTick);
69}
70
71void
72Root::timeSyncEnable(bool en)
73{
74 if (en == _enabled)
75 return;
76 _enabled = en;
77 if (_enabled) {
78 // Get event going.
79 Tick periods = ((curTick() + _periodTick - 1) / _periodTick);
80 Tick nextPeriod = periods * _periodTick;
81 schedule(&syncEvent, nextPeriod);
82 } else {
83 // Stop event.
84 deschedule(&syncEvent);
85 }
86}
87
88/// Configure the period for time sync events.
89void
90Root::timeSyncPeriod(Time newPeriod)
91{
92 bool en = timeSyncEnabled();
93 _period = newPeriod;
94 _periodTick = _period.getTick();
95 timeSyncEnable(en);
96}
97
98/// Set the threshold for time remaining to spin wait.
99void
100Root::timeSyncSpinThreshold(Time newThreshold)
101{
102 bool en = timeSyncEnabled();
103 _spinThreshold = newThreshold;
104 timeSyncEnable(en);
105}
106
107Root::Root(RootParams *p)
108 : SimObject(p), _enabled(false), _periodTick(p->time_sync_period),
109 syncEvent([this]{ timeSync(); }, name())
110{
111 _period.setTick(p->time_sync_period);
112 _spinThreshold.setTick(p->time_sync_spin_threshold);
113
114 assert(_root == NULL);
115 _root = this;
116 lastTime.setTimer();
117
118 simQuantum = p->sim_quantum;
119}
120
121void
122Root::startup()
123{
124 timeSyncEnable(params()->time_sync_enable);
125}
126
127void
128Root::serialize(CheckpointOut &cp) const
129{
130 SERIALIZE_SCALAR(FullSystem);
131 std::string isa = THE_ISA_STR;
132 SERIALIZE_SCALAR(isa);
133}
134
135
136bool FullSystem;
137unsigned int FullSystemInt;
138
139Root *
140RootParams::create()
141{
142 static bool created = false;
143 if (created)
144 panic("only one root object allowed!");
145
146 created = true;
147
148 FullSystem = full_system;
149 FullSystemInt = full_system ? 1 : 0;
150
151 return new Root(this);
152}
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