sc_time.cc revision 13177:7b750aeab360 
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 <sstream>
31#include <vector>
32
33#include "base/logging.hh"
34#include "base/types.hh"
35#include "python/pybind11/pybind.hh"
36#include "systemc/core/python.hh"
37#include "systemc/ext/core/sc_main.hh"
38#include "systemc/ext/core/sc_time.hh"
39#include "systemc/ext/utils/sc_report_handler.hh"
40
41namespace sc_core
42{
43
44namespace
45{
46
47const char *TimeUnitNames[] = {
48    [SC_FS] = "fs",
49    [SC_PS] = "ps",
50    [SC_NS] = "ns",
51    [SC_US] = "us",
52    [SC_MS] = "ms",
53    [SC_SEC] = "s"
54};
55
56double TimeUnitScale[] = {
57    [SC_FS] = 1.0e-15,
58    [SC_PS] = 1.0e-12,
59    [SC_NS] = 1.0e-9,
60    [SC_US] = 1.0e-6,
61    [SC_MS] = 1.0e-3,
62    [SC_SEC] = 1.0
63};
64
65bool timeFixed = false;
66bool pythonReady = false;
67
68struct SetInfo
69{
70    SetInfo(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu) :
71        time(time), d(d), tu(tu)
72    {}
73
74    ::sc_core::sc_time *time;
75    double d;
76    ::sc_core::sc_time_unit tu;
77};
78std::vector<SetInfo> toSet;
79
80void
81setWork(sc_time *time, double d, ::sc_core::sc_time_unit tu)
82{
83    //XXX Assuming the time resolution is 1ps.
84    double scale = TimeUnitScale[tu] / TimeUnitScale[SC_PS];
85    // Accellera claims there is a linux bug, and that these next two
86    // lines work around them.
87    volatile double tmp = d * scale + 0.5;
88    *time = sc_time::from_value(static_cast<uint64_t>(tmp));
89}
90
91void
92fixTime()
93{
94    auto ticks = pybind11::module::import("m5.ticks");
95    auto fix_global_frequency = ticks.attr("fixGlobalFrequency");
96    fix_global_frequency();
97
98    for (auto &t: toSet)
99        setWork(t.time, t.d, t.tu);
100    toSet.clear();
101}
102
103void
104setGlobalFrequency(Tick ticks_per_second)
105{
106    auto ticks = pybind11::module::import("m5.ticks");
107    auto set_global_frequency = ticks.attr("setGlobalFrequency");
108    set_global_frequency(ticks_per_second);
109    fixTime();
110}
111
112void
113set(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu)
114{
115    // Only fix time once.
116    if (!timeFixed) {
117        timeFixed = true;
118
119        // If we've run, python is working and we haven't fixed time yet.
120        if (pythonReady)
121            fixTime();
122    }
123    if (pythonReady) {
124        // Time should be working. Set up this sc_time.
125        setWork(time, d, tu);
126    } else {
127        // Time isn't set up yet. Defer setting up this sc_time.
128        toSet.emplace_back(time, d, tu);
129    }
130}
131
132class TimeSetter : public ::sc_gem5::PythonReadyFunc
133{
134  public:
135    TimeSetter() : ::sc_gem5::PythonReadyFunc() {}
136
137    void
138    run() override
139    {
140        // Record that we've run and python/pybind should be usable.
141        pythonReady = true;
142
143        // If time is already fixed, let python know.
144        if (timeFixed)
145            fixTime();
146    }
147} timeSetter;
148
149double defaultUnit = 1.0e-9;
150
151} // anonymous namespace
152
153sc_time::sc_time() : val(0) {}
154
155sc_time::sc_time(double d, sc_time_unit tu)
156{
157    val = 0;
158    if (d != 0)
159        set(this, d, tu);
160}
161
162sc_time::sc_time(const sc_time &t)
163{
164    val = t.val;
165}
166
167sc_time::sc_time(double d, bool scale)
168{
169    //XXX Assuming the time resolution is 1ps.
170    if (scale)
171        set(this, d * defaultUnit, SC_SEC);
172    else
173        set(this, d, SC_PS);
174}
175
176sc_time::sc_time(sc_dt::uint64 v, bool scale)
177{
178    //XXX Assuming the time resolution is 1ps.
179    if (scale)
180        set(this, static_cast<double>(v) * defaultUnit, SC_SEC);
181    else
182        set(this, static_cast<double>(v), SC_PS);
183}
184
185sc_time &
186sc_time::operator = (const sc_time &t)
187{
188    val = t.val;
189    return *this;
190}
191
192sc_dt::uint64
193sc_time::value() const
194{
195    return val;
196}
197
198double
199sc_time::to_double() const
200{
201    return static_cast<double>(val);
202}
203double
204sc_time::to_seconds() const
205{
206    double d = to_double();
207    //XXX Assuming the time resolution is 1ps.
208    double scale = TimeUnitScale[SC_PS] / TimeUnitScale[SC_SEC];
209    return d * scale;
210}
211
212const std::string
213sc_time::to_string() const
214{
215    std::ostringstream ss;
216    print(ss);
217    return ss.str();
218}
219
220bool
221sc_time::operator == (const sc_time &t) const
222{
223    return val == t.val;
224}
225
226bool
227sc_time::operator != (const sc_time &t) const
228{
229    return val != t.val;
230}
231
232bool
233sc_time::operator < (const sc_time &t) const
234{
235    return val < t.val;
236}
237
238bool
239sc_time::operator <= (const sc_time &t) const
240{
241    return val <= t.val;
242}
243
244bool
245sc_time::operator > (const sc_time &t) const
246{
247    return val > t.val;
248}
249
250bool
251sc_time::operator >= (const sc_time &t) const
252{
253    return val >= t.val;
254}
255
256sc_time &
257sc_time::operator += (const sc_time &t)
258{
259    val += t.val;
260    return *this;
261}
262
263sc_time &
264sc_time::operator -= (const sc_time &t)
265{
266    val -= t.val;
267    return *this;
268}
269
270sc_time &
271sc_time::operator *= (double d)
272{
273    val = static_cast<int64_t>(static_cast<double>(val) * d + 0.5);
274    return *this;
275}
276
277sc_time &
278sc_time::operator /= (double d)
279{
280    val = static_cast<int64_t>(static_cast<double>(val) / d + 0.5);
281    return *this;
282}
283
284void
285sc_time::print(std::ostream &os) const
286{
287    if (val == 0) {
288        os << "0 s";
289    } else {
290        //XXX Assuming the time resolution is 1ps.
291        sc_time_unit tu = SC_PS;
292        uint64_t scaled = val;
293        while (tu < SC_SEC && (scaled % 1000) == 0) {
294            tu = (sc_time_unit)((int)tu + 1);
295            scaled /= 1000;
296        }
297
298        os << scaled << ' ' << TimeUnitNames[tu];
299    }
300}
301
302sc_time
303sc_time::from_value(sc_dt::uint64 u)
304{
305    sc_time t;
306    t.val = u;
307    return t;
308}
309
310sc_time
311sc_time::from_seconds(double d)
312{
313    sc_time t;
314    set(&t, d, SC_SEC);
315    return t;
316}
317
318sc_time
319sc_time::from_string(const char *str)
320{
321    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
322    return sc_time();
323}
324
325const sc_time
326operator + (const sc_time &a, const sc_time &b)
327{
328    return sc_time::from_value(a.value() + b.value());
329}
330
331const sc_time
332operator - (const sc_time &a, const sc_time &b)
333{
334    return sc_time::from_value(a.value() - b.value());
335}
336
337const sc_time
338operator * (const sc_time &t, double d)
339{
340    volatile double tmp = static_cast<double>(t.value()) * d + 0.5;
341    return sc_time::from_value(static_cast<int64_t>(tmp));
342}
343
344const sc_time
345operator * (double d, const sc_time &t)
346{
347    volatile double tmp = d * static_cast<double>(t.value()) + 0.5;
348    return sc_time::from_value(static_cast<int64_t>(tmp));
349}
350
351const sc_time
352operator / (const sc_time &t, double d)
353{
354    volatile double tmp = static_cast<double>(t.value()) / d + 0.5;
355    return sc_time::from_value(static_cast<int64_t>(tmp));
356}
357
358double
359operator / (const sc_time &t1, const sc_time &t2)
360{
361    return t1.to_double() / t2.to_double();
362}
363
364std::ostream &
365operator << (std::ostream &os, const sc_time &t)
366{
367    t.print(os);
368    return os;
369}
370
371const sc_time SC_ZERO_TIME;
372
373void
374sc_set_time_resolution(double d, sc_time_unit tu)
375{
376    if (d <= 0.0) {
377        SC_REPORT_ERROR("(E514) set time resolution failed",
378                "value not positive");
379    }
380    double dummy;
381    if (modf(log10(d), &dummy) != 0.0) {
382        SC_REPORT_ERROR("(E514) set time resolution failed",
383                "value not a power of ten");
384    }
385    if (sc_is_running()) {
386        SC_REPORT_ERROR("(E514) set time resolution failed",
387                "simulation running");
388    }
389    static bool specified = false;
390    if (specified) {
391        SC_REPORT_ERROR("(E514) set time resolution failed",
392                "already specified");
393    }
394    // This won't detect the timescale being fixed outside of systemc, but
395    // it's at least some protection.
396    if (timeFixed) {
397        SC_REPORT_ERROR("(E514) set time resolution failed",
398                "sc_time object(s) constructed");
399    }
400
401    // Normalize d to seconds.
402    d *= TimeUnitScale[tu];
403    if (d < TimeUnitScale[SC_FS]) {
404        SC_REPORT_ERROR("(E514) set time resolution failed",
405                "value smaller than 1 fs");
406    }
407    // Change d from a period to a frequency.
408    d = 1 / d;
409    // Convert to integer ticks.
410    Tick ticks_per_second = static_cast<Tick>(d);
411    setGlobalFrequency(ticks_per_second);
412    specified = true;
413}
414
415sc_time
416sc_get_time_resolution()
417{
418    return sc_time::from_value(1);
419}
420
421const sc_time &
422sc_max_time()
423{
424    static const sc_time MaxScTime = sc_time::from_value(MaxTick);
425    return MaxScTime;
426}
427
428void
429sc_set_default_time_unit(double d, sc_time_unit tu)
430{
431    if (d < 0.0) {
432        SC_REPORT_ERROR("(E515) set default time unit failed",
433                "value not positive");
434    }
435    double dummy;
436    if (modf(log10(d), &dummy) != 0.0) {
437        SC_REPORT_ERROR("(E515) set default time unit failed",
438                "value not a power of ten");
439    }
440    if (sc_is_running()) {
441        SC_REPORT_ERROR("(E515) set default time unit failed",
442                "simulation running");
443    }
444    static bool specified = false;
445    if (specified) {
446        SC_REPORT_ERROR("(E515) set default time unit failed",
447                "already specified");
448    }
449    // This won't detect the timescale being fixed outside of systemc, but
450    // it's at least some protection.
451    if (timeFixed) {
452        SC_REPORT_ERROR("(E515) set default time unit failed",
453                "sc_time object(s) constructed");
454    }
455
456    // Normalize d to seconds.
457    defaultUnit = d * TimeUnitScale[tu];
458    specified = true;
459}
460
461sc_time
462sc_get_default_time_unit()
463{
464    return sc_time(defaultUnit, SC_SEC);
465}
466
467sc_time_tuple::sc_time_tuple(const sc_time &)
468{
469    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
470}
471
472bool
473sc_time_tuple::has_value() const
474{
475    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
476    return false;
477}
478
479sc_dt::uint64
480sc_time_tuple::value() const
481{
482    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
483    return 0;
484}
485
486const char *
487sc_time_tuple::unit_symbol() const
488{
489    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
490    return "";
491}
492
493double
494sc_time_tuple::to_double() const
495{
496    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
497    return 0.0;
498}
499
500std::string
501sc_time_tuple::to_string() const
502{
503    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
504    return "";
505}
506
507} // namespace sc_core
508