root.cc (7826:c06505ff551e) root.cc (7861:4ebff121cc0e)
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * Copyright (c) 2011 Advanced Micro Devices
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the

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22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 * Steve Reinhardt
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

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

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
30 */
31
32#include "base/misc.hh"
32 */
33
34#include "base/misc.hh"
33#include "params/Root.hh"
34#include "sim/sim_object.hh"
35#include "sim/core.hh"
36#include "sim/root.hh"
35
37
36// Dummy Object
37struct Root : public SimObject
38Root *Root::_root = NULL;
39
40/*
41 * This function is called periodically by an event in M5 and ensures that
42 * at least as much real time has passed between invocations as simulated time.
43 * If not, the function either sleeps, or if the difference is small enough
44 * spin waits.
45 */
46void
47Root::timeSync()
38{
48{
39 Root(RootParams *params) : SimObject(params) {}
40};
49 Time cur_time, diff, period = timeSyncPeriod();
41
50
51 do {
52 cur_time.setTimer();
53 diff = cur_time - lastTime;
54 Time remainder = period - diff;
55 if (diff < period && remainder > _spinThreshold) {
56 DPRINTF(TimeSync, "Sleeping to sync with real time.\n");
57 // Sleep until the end of the period, or until a signal.
58 sleep(remainder);
59 // Refresh the current time.
60 cur_time.setTimer();
61 }
62 } while (diff < period);
63 lastTime = cur_time;
64 schedule(&syncEvent, curTick() + _periodTick);
65}
66
67void
68Root::timeSyncEnable(bool en)
69{
70 if (en == _enabled)
71 return;
72 _enabled = en;
73 if (_enabled) {
74 // Get event going.
75 Tick periods = ((curTick() + _periodTick - 1) / _periodTick);
76 Tick nextPeriod = periods * _periodTick;
77 schedule(&syncEvent, nextPeriod);
78 } else {
79 // Stop event.
80 deschedule(&syncEvent);
81 }
82}
83
84/// Configure the period for time sync events.
85void
86Root::timeSyncPeriod(Time newPeriod)
87{
88 bool en = timeSyncEnabled();
89 _period = newPeriod;
90 _periodTick = _period.nsec() * SimClock::Int::ns +
91 _period.sec() * SimClock::Int::s;
92 timeSyncEnable(en);
93}
94
95/// Set the threshold for time remaining to spin wait.
96void
97Root::timeSyncSpinThreshold(Time newThreshold)
98{
99 bool en = timeSyncEnabled();
100 _spinThreshold = newThreshold;
101 timeSyncEnable(en);
102}
103
104Root::Root(RootParams *p) : SimObject(p), _enabled(false),
105 _periodTick(p->time_sync_period), syncEvent(this)
106{
107 uint64_t nsecs = p->time_sync_period / SimClock::Int::ns;
108 _period.set(nsecs / Time::NSEC_PER_SEC, nsecs % Time::NSEC_PER_SEC);
109 nsecs = p->time_sync_spin_threshold / SimClock::Int::ns;
110 _spinThreshold.set(nsecs / Time::NSEC_PER_SEC,
111 nsecs % Time::NSEC_PER_SEC);
112
113 assert(_root == NULL);
114 _root = this;
115 lastTime.setTimer();
116 timeSyncEnable(p->time_sync_enable);
117}
118
42Root *
43RootParams::create()
44{
45 static bool created = false;
46 if (created)
47 panic("only one root object allowed!");
48
49 created = true;
50
51 return new Root(this);
52}
119Root *
120RootParams::create()
121{
122 static bool created = false;
123 if (created)
124 panic("only one root object allowed!");
125
126 created = true;
127
128 return new Root(this);
129}