sc_time.cc revision 13252:8814e5d87a48 
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 "sim/core.hh"
37#include "systemc/core/python.hh"
38#include "systemc/core/time.hh"
39#include "systemc/ext/core/sc_main.hh"
40#include "systemc/ext/core/sc_time.hh"
41#include "systemc/ext/utils/sc_report_handler.hh"
42
43namespace sc_core
44{
45
46namespace
47{
48
49bool timeFixed = false;
50bool pythonReady = false;
51
52struct SetInfo
53{
54    SetInfo(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu) :
55        time(time), d(d), tu(tu)
56    {}
57
58    ::sc_core::sc_time *time;
59    double d;
60    ::sc_core::sc_time_unit tu;
61};
62std::vector<SetInfo> toSet;
63
64void
65setWork(sc_time *time, double d, ::sc_core::sc_time_unit tu)
66{
67    double scale = sc_gem5::TimeUnitScale[tu] * SimClock::Float::s;
68    // Accellera claims there is a linux bug, and that these next two
69    // lines work around them.
70    volatile double tmp = d * scale + 0.5;
71    *time = sc_time::from_value(static_cast<uint64_t>(tmp));
72}
73
74void
75fixTime()
76{
77    auto ticks = pybind11::module::import("m5.ticks");
78    auto fix_global_frequency = ticks.attr("fixGlobalFrequency");
79    fix_global_frequency();
80
81    for (auto &t: toSet)
82        setWork(t.time, t.d, t.tu);
83    toSet.clear();
84}
85
86void
87attemptToFixTime()
88{
89    // Only fix time once.
90    if (!timeFixed) {
91        timeFixed = true;
92
93        // If we've run, python is working and we haven't fixed time yet.
94        if (pythonReady)
95            fixTime();
96    }
97}
98
99void
100setGlobalFrequency(Tick ticks_per_second)
101{
102    auto ticks = pybind11::module::import("m5.ticks");
103    auto set_global_frequency = ticks.attr("setGlobalFrequency");
104    set_global_frequency(ticks_per_second);
105    fixTime();
106}
107
108void
109set(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu)
110{
111    if (d != 0)
112        attemptToFixTime();
113    if (pythonReady) {
114        // Time should be working. Set up this sc_time.
115        setWork(time, d, tu);
116    } else {
117        // Time isn't set up yet. Defer setting up this sc_time.
118        toSet.emplace_back(time, d, tu);
119    }
120}
121
122class TimeSetter : public ::sc_gem5::PythonReadyFunc
123{
124  public:
125    TimeSetter() : ::sc_gem5::PythonReadyFunc() {}
126
127    void
128    run() override
129    {
130        // Record that we've run and python/pybind should be usable.
131        pythonReady = true;
132
133        // If time is already fixed, let python know.
134        if (timeFixed)
135            fixTime();
136    }
137} timeSetter;
138
139double defaultUnit = 1.0e-9;
140
141} // anonymous namespace
142
143sc_time::sc_time() : val(0) {}
144
145sc_time::sc_time(double d, sc_time_unit tu)
146{
147    val = 0;
148    set(this, d, tu);
149}
150
151sc_time::sc_time(const sc_time &t)
152{
153    val = t.val;
154}
155
156sc_time::sc_time(double d, bool scale)
157{
158    double scaler = scale ? defaultUnit : SimClock::Float::Hz;
159    set(this, d * scaler, SC_SEC);
160}
161
162sc_time::sc_time(sc_dt::uint64 v, bool scale)
163{
164    double scaler = scale ? defaultUnit : SimClock::Float::Hz;
165    set(this, static_cast<double>(v) * scaler, SC_SEC);
166}
167
168sc_time &
169sc_time::operator = (const sc_time &t)
170{
171    val = t.val;
172    return *this;
173}
174
175sc_dt::uint64
176sc_time::value() const
177{
178    return val;
179}
180
181double
182sc_time::to_double() const
183{
184    return static_cast<double>(val);
185}
186double
187sc_time::to_seconds() const
188{
189    return to_double() * SimClock::Float::Hz;
190}
191
192const std::string
193sc_time::to_string() const
194{
195    std::ostringstream ss;
196    print(ss);
197    return ss.str();
198}
199
200bool
201sc_time::operator == (const sc_time &t) const
202{
203    return val == t.val;
204}
205
206bool
207sc_time::operator != (const sc_time &t) const
208{
209    return val != t.val;
210}
211
212bool
213sc_time::operator < (const sc_time &t) const
214{
215    return val < t.val;
216}
217
218bool
219sc_time::operator <= (const sc_time &t) const
220{
221    return val <= t.val;
222}
223
224bool
225sc_time::operator > (const sc_time &t) const
226{
227    return val > t.val;
228}
229
230bool
231sc_time::operator >= (const sc_time &t) const
232{
233    return val >= t.val;
234}
235
236sc_time &
237sc_time::operator += (const sc_time &t)
238{
239    val += t.val;
240    return *this;
241}
242
243sc_time &
244sc_time::operator -= (const sc_time &t)
245{
246    val -= t.val;
247    return *this;
248}
249
250sc_time &
251sc_time::operator *= (double d)
252{
253    val = static_cast<int64_t>(static_cast<double>(val) * d + 0.5);
254    return *this;
255}
256
257sc_time &
258sc_time::operator /= (double d)
259{
260    val = static_cast<int64_t>(static_cast<double>(val) / d + 0.5);
261    return *this;
262}
263
264void
265sc_time::print(std::ostream &os) const
266{
267    if (val == 0) {
268        os << "0 s";
269    } else {
270        Tick frequency = SimClock::Frequency;
271
272        // Shrink the frequency by scaling down the time period, ie converting
273        // it from cycles per second to cycles per millisecond, etc.
274        sc_time_unit tu = SC_SEC;
275        while (tu > 1 && (frequency % 1000 == 0)) {
276            tu = (sc_time_unit)((int)tu - 1);
277            frequency /= 1000;
278        }
279
280        // Convert the frequency into a period.
281        Tick period;
282        if (frequency > 1) {
283            tu = (sc_time_unit)((int)tu - 1);
284            period = 1000 / frequency;
285        } else {
286            period = frequency;
287        }
288
289        // Scale our integer value by the period.
290        uint64_t scaled = val * period;
291
292        // Shrink the scaled time value by increasing the size of the units
293        // it's measured by, avoiding fractional parts.
294        while (tu < SC_SEC && (scaled % 1000) == 0) {
295            tu = (sc_time_unit)((int)tu + 1);
296            scaled /= 1000;
297        }
298
299        os << scaled << ' ' << sc_gem5::TimeUnitNames[tu];
300    }
301}
302
303sc_time
304sc_time::from_value(sc_dt::uint64 u)
305{
306    if (u)
307        attemptToFixTime();
308    sc_time t;
309    t.val = u;
310    return t;
311}
312
313sc_time
314sc_time::from_seconds(double d)
315{
316    sc_time t;
317    set(&t, d, SC_SEC);
318    return t;
319}
320
321sc_time
322sc_time::from_string(const char *str)
323{
324    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
325    return sc_time();
326}
327
328const sc_time
329operator + (const sc_time &a, const sc_time &b)
330{
331    return sc_time::from_value(a.value() + b.value());
332}
333
334const sc_time
335operator - (const sc_time &a, const sc_time &b)
336{
337    return sc_time::from_value(a.value() - b.value());
338}
339
340const sc_time
341operator * (const sc_time &t, double d)
342{
343    volatile double tmp = static_cast<double>(t.value()) * d + 0.5;
344    return sc_time::from_value(static_cast<int64_t>(tmp));
345}
346
347const sc_time
348operator * (double d, const sc_time &t)
349{
350    volatile double tmp = d * static_cast<double>(t.value()) + 0.5;
351    return sc_time::from_value(static_cast<int64_t>(tmp));
352}
353
354const sc_time
355operator / (const sc_time &t, double d)
356{
357    volatile double tmp = static_cast<double>(t.value()) / d + 0.5;
358    return sc_time::from_value(static_cast<int64_t>(tmp));
359}
360
361double
362operator / (const sc_time &t1, const sc_time &t2)
363{
364    return t1.to_double() / t2.to_double();
365}
366
367std::ostream &
368operator << (std::ostream &os, const sc_time &t)
369{
370    t.print(os);
371    return os;
372}
373
374const sc_time SC_ZERO_TIME;
375
376void
377sc_set_time_resolution(double d, sc_time_unit tu)
378{
379    if (d <= 0.0) {
380        SC_REPORT_ERROR("(E514) set time resolution failed",
381                "value not positive");
382    }
383    double dummy;
384    if (modf(log10(d), &dummy) != 0.0) {
385        SC_REPORT_ERROR("(E514) set time resolution failed",
386                "value not a power of ten");
387    }
388    if (sc_is_running()) {
389        SC_REPORT_ERROR("(E514) set time resolution failed",
390                "simulation running");
391    }
392    static bool specified = false;
393    if (specified) {
394        SC_REPORT_ERROR("(E514) set time resolution failed",
395                "already specified");
396    }
397    // This won't detect the timescale being fixed outside of systemc, but
398    // it's at least some protection.
399    if (timeFixed) {
400        SC_REPORT_ERROR("(E514) set time resolution failed",
401                "sc_time object(s) constructed");
402    }
403
404    double seconds = d * sc_gem5::TimeUnitScale[tu];
405    if (seconds < sc_gem5::TimeUnitScale[SC_FS]) {
406        SC_REPORT_ERROR("(E514) set time resolution failed",
407                "value smaller than 1 fs");
408    }
409
410    if (seconds > defaultUnit) {
411        SC_REPORT_WARNING(
412                "(W516) default time unit changed to time resolution", "");
413        defaultUnit = seconds;
414    }
415
416    // Get rid of fractional parts of d.
417    while (d < 1.0 && tu > SC_FS) {
418        d *= 1000;
419        tu = (sc_time_unit)(tu - 1);
420    }
421
422    Tick ticks_per_second =
423        sc_gem5::TimeUnitFrequency[tu] / static_cast<Tick>(d);
424    setGlobalFrequency(ticks_per_second);
425    specified = true;
426}
427
428sc_time
429sc_get_time_resolution()
430{
431    return sc_time::from_value(1);
432}
433
434const sc_time &
435sc_max_time()
436{
437    static const sc_time MaxScTime = sc_time::from_value(MaxTick);
438    return MaxScTime;
439}
440
441void
442sc_set_default_time_unit(double d, sc_time_unit tu)
443{
444    if (d < 0.0) {
445        SC_REPORT_ERROR("(E515) set default time unit failed",
446                "value not positive");
447    }
448    double dummy;
449    if (modf(log10(d), &dummy) != 0.0) {
450        SC_REPORT_ERROR("(E515) set default time unit failed",
451                "value not a power of ten");
452    }
453    if (sc_is_running()) {
454        SC_REPORT_ERROR("(E515) set default time unit failed",
455                "simulation running");
456    }
457    static bool specified = false;
458    if (specified) {
459        SC_REPORT_ERROR("(E515) set default time unit failed",
460                "already specified");
461    }
462    // This won't detect the timescale being fixed outside of systemc, but
463    // it's at least some protection.
464    if (timeFixed) {
465        SC_REPORT_ERROR("(E515) set default time unit failed",
466                "sc_time object(s) constructed");
467    }
468
469    // Normalize d to seconds.
470    defaultUnit = d * sc_gem5::TimeUnitScale[tu];
471    specified = true;
472
473    double resolution = SimClock::Float::Hz;
474    if (resolution == 0.0)
475        resolution = sc_gem5::TimeUnitScale[SC_PS];
476    if (defaultUnit < resolution) {
477        SC_REPORT_ERROR("(E515) set default time unit failed",
478                "value smaller than time resolution");
479    }
480}
481
482sc_time
483sc_get_default_time_unit()
484{
485    return sc_time(defaultUnit, SC_SEC);
486}
487
488sc_time_tuple::sc_time_tuple(const sc_time &)
489{
490    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
491}
492
493bool
494sc_time_tuple::has_value() const
495{
496    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
497    return false;
498}
499
500sc_dt::uint64
501sc_time_tuple::value() const
502{
503    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
504    return 0;
505}
506
507const char *
508sc_time_tuple::unit_symbol() const
509{
510    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
511    return "";
512}
513
514double
515sc_time_tuple::to_double() const
516{
517    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
518    return 0.0;
519}
520
521std::string
522sc_time_tuple::to_string() const
523{
524    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
525    return "";
526}
527
528} // namespace sc_core
529