sc_time.cc revision 13151:5ce517287782 
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 <vector>
31
32#include "base/logging.hh"
33#include "base/types.hh"
34#include "python/pybind11/pybind.hh"
35#include "systemc/core/python.hh"
36#include "systemc/ext/core/sc_main.hh"
37#include "systemc/ext/core/sc_time.hh"
38#include "systemc/ext/utils/sc_report_handler.hh"
39
40namespace sc_core
41{
42
43namespace
44{
45
46const char *TimeUnitNames[] = {
47    [SC_FS] = "fs",
48    [SC_PS] = "ps",
49    [SC_NS] = "ns",
50    [SC_US] = "us",
51    [SC_MS] = "ms",
52    [SC_SEC] = "s"
53};
54
55double TimeUnitScale[] = {
56    [SC_FS] = 1.0e-15,
57    [SC_PS] = 1.0e-12,
58    [SC_NS] = 1.0e-9,
59    [SC_US] = 1.0e-6,
60    [SC_MS] = 1.0e-3,
61    [SC_SEC] = 1.0
62};
63
64bool timeFixed = false;
65bool pythonReady = false;
66
67struct SetInfo
68{
69    SetInfo(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu) :
70        time(time), d(d), tu(tu)
71    {}
72
73    ::sc_core::sc_time *time;
74    double d;
75    ::sc_core::sc_time_unit tu;
76};
77std::vector<SetInfo> toSet;
78
79void
80setWork(sc_time *time, double d, ::sc_core::sc_time_unit tu)
81{
82    //XXX Assuming the time resolution is 1ps.
83    double scale = TimeUnitScale[tu] / TimeUnitScale[SC_PS];
84    // Accellera claims there is a linux bug, and that these next two
85    // lines work around them.
86    volatile double tmp = d * scale + 0.5;
87    *time = sc_time::from_value(static_cast<uint64_t>(tmp));
88}
89
90void
91fixTime()
92{
93    auto ticks = pybind11::module::import("m5.ticks");
94    auto fix_global_frequency = ticks.attr("fixGlobalFrequency");
95    fix_global_frequency();
96
97    for (auto &t: toSet)
98        setWork(t.time, t.d, t.tu);
99    toSet.clear();
100}
101
102void
103setGlobalFrequency(Tick ticks_per_second)
104{
105    auto ticks = pybind11::module::import("m5.ticks");
106    auto set_global_frequency = ticks.attr("setGlobalFrequency");
107    set_global_frequency(ticks_per_second);
108    fixTime();
109}
110
111void
112set(::sc_core::sc_time *time, double d, ::sc_core::sc_time_unit tu)
113{
114    // Only fix time once.
115    if (!timeFixed) {
116        timeFixed = true;
117
118        // If we've run, python is working and we haven't fixed time yet.
119        if (pythonReady)
120            fixTime();
121    }
122    if (pythonReady) {
123        // Time should be working. Set up this sc_time.
124        setWork(time, d, tu);
125    } else {
126        // Time isn't set up yet. Defer setting up this sc_time.
127        toSet.emplace_back(time, d, tu);
128    }
129}
130
131class TimeSetter : public ::sc_gem5::PythonReadyFunc
132{
133  public:
134    TimeSetter() : ::sc_gem5::PythonReadyFunc() {}
135
136    void
137    run() override
138    {
139        // Record that we've run and python/pybind should be usable.
140        pythonReady = true;
141
142        // If time is already fixed, let python know.
143        if (timeFixed)
144            fixTime();
145    }
146} timeSetter;
147
148double defaultUnit = 1.0e-9;
149
150} // anonymous namespace
151
152sc_time::sc_time() : val(0) {}
153
154sc_time::sc_time(double d, sc_time_unit tu)
155{
156    val = 0;
157    if (d != 0)
158        set(this, d, tu);
159}
160
161sc_time::sc_time(const sc_time &t)
162{
163    val = t.val;
164}
165
166sc_time::sc_time(double d, bool scale)
167{
168    //XXX Assuming the time resolution is 1ps.
169    if (scale)
170        set(this, d * defaultUnit, SC_SEC);
171    else
172        set(this, d, SC_PS);
173}
174
175sc_time::sc_time(sc_dt::uint64 v, bool scale)
176{
177    //XXX Assuming the time resolution is 1ps.
178    if (scale)
179        set(this, static_cast<double>(v) * defaultUnit, SC_SEC);
180    else
181        set(this, static_cast<double>(v), SC_PS);
182}
183
184sc_time &
185sc_time::operator = (const sc_time &t)
186{
187    val = t.val;
188    return *this;
189}
190
191sc_dt::uint64
192sc_time::value() const
193{
194    return val;
195}
196
197double
198sc_time::to_double() const
199{
200    return static_cast<double>(val);
201}
202double
203sc_time::to_seconds() const
204{
205    double d = to_double();
206    //XXX Assuming the time resolution is 1ps.
207    double scale = TimeUnitScale[SC_PS] / TimeUnitScale[SC_SEC];
208    return d * scale;
209}
210
211const std::string
212sc_time::to_string() const
213{
214    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
215    return "";
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
236bool
237sc_time::operator <= (const sc_time &t) const
238{
239    return val <= t.val;
240}
241
242bool
243sc_time::operator > (const sc_time &t) const
244{
245    return val > t.val;
246}
247
248bool
249sc_time::operator >= (const sc_time &t) const
250{
251    return val >= t.val;
252}
253
254sc_time &
255sc_time::operator += (const sc_time &t)
256{
257    val += t.val;
258    return *this;
259}
260
261sc_time &
262sc_time::operator -= (const sc_time &t)
263{
264    val -= t.val;
265    return *this;
266}
267
268sc_time &
269sc_time::operator *= (double d)
270{
271    val = static_cast<int64_t>(static_cast<double>(val) * d + 0.5);
272    return *this;
273}
274
275sc_time &
276sc_time::operator /= (double d)
277{
278    val = static_cast<int64_t>(static_cast<double>(val) / d + 0.5);
279    return *this;
280}
281
282void
283sc_time::print(std::ostream &os) const
284{
285    if (val == 0) {
286        os << "0 s";
287    } else {
288        //XXX Assuming the time resolution is 1ps.
289        sc_time_unit tu = SC_PS;
290        uint64_t scaled = val;
291        while (tu < SC_SEC && (scaled % 1000) == 0) {
292            tu = (sc_time_unit)((int)tu + 1);
293            scaled /= 1000;
294        }
295
296        os << scaled << ' ' << TimeUnitNames[tu];
297    }
298}
299
300sc_time
301sc_time::from_value(sc_dt::uint64 u)
302{
303    sc_time t;
304    t.val = u;
305    return t;
306}
307
308sc_time
309sc_time::from_seconds(double d)
310{
311    sc_time t;
312    set(&t, d, SC_SEC);
313    return t;
314}
315
316sc_time
317sc_time::from_string(const char *str)
318{
319    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
320    return sc_time();
321}
322
323const sc_time
324operator + (const sc_time &a, const sc_time &b)
325{
326    return sc_time::from_value(a.value() + b.value());
327}
328
329const sc_time
330operator - (const sc_time &a, const sc_time &b)
331{
332    return sc_time::from_value(a.value() - b.value());
333}
334
335const sc_time
336operator * (const sc_time &t, double d)
337{
338    volatile double tmp = static_cast<double>(t.value()) * d + 0.5;
339    return sc_time::from_value(static_cast<int64_t>(tmp));
340}
341
342const sc_time
343operator * (double d, const sc_time &t)
344{
345    volatile double tmp = d * static_cast<double>(t.value()) + 0.5;
346    return sc_time::from_value(static_cast<int64_t>(tmp));
347}
348
349const sc_time
350operator / (const sc_time &t, double d)
351{
352    volatile double tmp = static_cast<double>(t.value()) / d + 0.5;
353    return sc_time::from_value(static_cast<int64_t>(tmp));
354}
355
356double
357operator / (const sc_time &t1, const sc_time &t2)
358{
359    return t1.to_double() / t2.to_double();
360}
361
362std::ostream &
363operator << (std::ostream &os, const sc_time &t)
364{
365    t.print(os);
366    return os;
367}
368
369const sc_time SC_ZERO_TIME;
370
371void
372sc_set_time_resolution(double d, sc_time_unit tu)
373{
374    if (d <= 0.0) {
375        SC_REPORT_ERROR("(E514) set time resolution failed",
376                "value not positive");
377    }
378    double dummy;
379    if (modf(log10(d), &dummy) != 0.0) {
380        SC_REPORT_ERROR("(E514) set time resolution failed",
381                "value not a power of ten");
382    }
383    if (sc_is_running()) {
384        SC_REPORT_ERROR("(E514) set time resolution failed",
385                "simulation running");
386    }
387    static bool specified = false;
388    if (specified) {
389        SC_REPORT_ERROR("(E514) set time resolution failed",
390                "already specified");
391    }
392    // This won't detect the timescale being fixed outside of systemc, but
393    // it's at least some protection.
394    if (timeFixed) {
395        SC_REPORT_ERROR("(E514) set time resolution failed",
396                "sc_time object(s) constructed");
397    }
398
399    // Normalize d to seconds.
400    d *= TimeUnitScale[tu];
401    if (d < TimeUnitScale[SC_FS]) {
402        SC_REPORT_ERROR("(E514) set time resolution failed",
403                "value smaller than 1 fs");
404    }
405    // Change d from a period to a frequency.
406    d = 1 / d;
407    // Convert to integer ticks.
408    Tick ticks_per_second = static_cast<Tick>(d);
409    setGlobalFrequency(ticks_per_second);
410    specified = true;
411}
412
413sc_time
414sc_get_time_resolution()
415{
416    return sc_time::from_value(1);
417}
418
419const sc_time &
420sc_max_time()
421{
422    static const sc_time MaxScTime = sc_time::from_value(MaxTick);
423    return MaxScTime;
424}
425
426void
427sc_set_default_time_unit(double d, sc_time_unit tu)
428{
429    if (d < 0.0) {
430        SC_REPORT_ERROR("(E515) set default time unit failed",
431                "value not positive");
432    }
433    double dummy;
434    if (modf(log10(d), &dummy) != 0.0) {
435        SC_REPORT_ERROR("(E515) set default time unit failed",
436                "value not a power of ten");
437    }
438    if (sc_is_running()) {
439        SC_REPORT_ERROR("(E515) set default time unit failed",
440                "simulation running");
441    }
442    static bool specified = false;
443    if (specified) {
444        SC_REPORT_ERROR("(E515) set default time unit failed",
445                "already specified");
446    }
447    // This won't detect the timescale being fixed outside of systemc, but
448    // it's at least some protection.
449    if (timeFixed) {
450        SC_REPORT_ERROR("(E515) set default time unit failed",
451                "sc_time object(s) constructed");
452    }
453
454    // Normalize d to seconds.
455    defaultUnit = d * TimeUnitScale[tu];
456    specified = true;
457}
458
459sc_time
460sc_get_default_time_unit()
461{
462    return sc_time(defaultUnit, SC_SEC);
463}
464
465sc_time_tuple::sc_time_tuple(const sc_time &)
466{
467    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
468}
469
470bool
471sc_time_tuple::has_value() const
472{
473    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
474    return false;
475}
476
477sc_dt::uint64
478sc_time_tuple::value() const
479{
480    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
481    return 0;
482}
483
484const char *
485sc_time_tuple::unit_symbol() const
486{
487    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
488    return "";
489}
490
491double
492sc_time_tuple::to_double() const
493{
494    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
495    return 0.0;
496}
497
498std::string
499sc_time_tuple::to_string() const
500{
501    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
502    return "";
503}
504
505} // namespace sc_core
506