summaryrefslogtreecommitdiff
path: root/Python/pytime.c
blob: beeab87e2c7399f3a6ee0e6553317bd3b7f74752 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
#include "Python.h"
#ifdef MS_WINDOWS
#include <windows.h>
#endif

#if defined(__APPLE__) && defined(HAVE_GETTIMEOFDAY) && defined(HAVE_FTIME)
  /*
   * _PyTime_gettimeofday falls back to ftime when getttimeofday fails because the latter
   * might fail on some platforms. This fallback is unwanted on MacOSX because
   * that makes it impossible to use a binary build on OSX 10.4 on earlier
   * releases of the OS. Therefore claim we don't support ftime.
   */
# undef HAVE_FTIME
#endif

#if defined(HAVE_FTIME) && !defined(MS_WINDOWS)
#include <sys/timeb.h>
extern int ftime(struct timeb *);
#endif

static void
pygettimeofday(_PyTime_timeval *tp, _Py_clock_info_t *info)
{
#ifdef MS_WINDOWS
    FILETIME system_time;
    ULARGE_INTEGER large;
    ULONGLONG microseconds;

    GetSystemTimeAsFileTime(&system_time);
    large.u.LowPart = system_time.dwLowDateTime;
    large.u.HighPart = system_time.dwHighDateTime;
    /* 11,644,473,600,000,000: number of microseconds between
       the 1st january 1601 and the 1st january 1970 (369 years + 89 leap
       days). */
    microseconds = large.QuadPart / 10 - 11644473600000000;
    tp->tv_sec = microseconds / 1000000;
    tp->tv_usec = microseconds % 1000000;
    if (info) {
        DWORD timeAdjustment, timeIncrement;
        BOOL isTimeAdjustmentDisabled;

        info->implementation = "GetSystemTimeAsFileTime()";
        info->monotonic = 0;
        (void) GetSystemTimeAdjustment(&timeAdjustment, &timeIncrement,
                                       &isTimeAdjustmentDisabled);
        info->resolution = timeIncrement * 1e-7;
        info->adjustable = 1;
    }
#else
    /* There are three ways to get the time:
      (1) gettimeofday() -- resolution in microseconds
      (2) ftime() -- resolution in milliseconds
      (3) time() -- resolution in seconds
      In all cases the return value in a timeval struct.
      Since on some systems (e.g. SCO ODT 3.0) gettimeofday() may
      fail, so we fall back on ftime() or time().
      Note: clock resolution does not imply clock accuracy! */

#ifdef HAVE_GETTIMEOFDAY
    int err;
#ifdef GETTIMEOFDAY_NO_TZ
    err = gettimeofday(tp);
#else
    err = gettimeofday(tp, (struct timezone *)NULL);
#endif
    if (err == 0) {
        if (info) {
            info->implementation = "gettimeofday()";
            info->resolution = 1e-6;
            info->monotonic = 0;
            info->adjustable = 1;
        }
        return;
    }
#endif   /* HAVE_GETTIMEOFDAY */

#if defined(HAVE_FTIME)
    {
        struct timeb t;
        ftime(&t);
        tp->tv_sec = t.time;
        tp->tv_usec = t.millitm * 1000;
        if (info) {
            info->implementation = "ftime()";
            info->resolution = 1e-3;
            info->monotonic = 0;
            info->adjustable = 1;
        }
    }
#else /* !HAVE_FTIME */
    tp->tv_sec = time(NULL);
    tp->tv_usec = 0;
    if (info) {
        info->implementation = "time()";
        info->resolution = 1.0;
        info->monotonic = 0;
        info->adjustable = 1;
    }
#endif /* !HAVE_FTIME */

#endif /* MS_WINDOWS */
}

void
_PyTime_gettimeofday(_PyTime_timeval *tp)
{
    pygettimeofday(tp, NULL);
}

void
_PyTime_gettimeofday_info(_PyTime_timeval *tp, _Py_clock_info_t *info)
{
    pygettimeofday(tp, info);
}

static void
error_time_t_overflow(void)
{
    PyErr_SetString(PyExc_OverflowError,
                    "timestamp out of range for platform time_t");
}

time_t
_PyLong_AsTime_t(PyObject *obj)
{
#if defined(HAVE_LONG_LONG) && SIZEOF_TIME_T == SIZEOF_LONG_LONG
    PY_LONG_LONG val;
    val = PyLong_AsLongLong(obj);
#else
    long val;
    assert(sizeof(time_t) <= sizeof(long));
    val = PyLong_AsLong(obj);
#endif
    if (val == -1 && PyErr_Occurred()) {
        if (PyErr_ExceptionMatches(PyExc_OverflowError))
            error_time_t_overflow();
        return -1;
    }
    return (time_t)val;
}

PyObject *
_PyLong_FromTime_t(time_t t)
{
#if defined(HAVE_LONG_LONG) && SIZEOF_TIME_T == SIZEOF_LONG_LONG
    return PyLong_FromLongLong((PY_LONG_LONG)t);
#else
    assert(sizeof(time_t) <= sizeof(long));
    return PyLong_FromLong((long)t);
#endif
}

static int
_PyTime_ObjectToDenominator(PyObject *obj, time_t *sec, long *numerator,
                            double denominator)
{
    assert(denominator <= LONG_MAX);
    if (PyFloat_Check(obj)) {
        double d, intpart, err;
        /* volatile avoids unsafe optimization on float enabled by gcc -O3 */
        volatile double floatpart;

        d = PyFloat_AsDouble(obj);
        floatpart = modf(d, &intpart);
        if (floatpart < 0) {
            floatpart = 1.0 + floatpart;
            intpart -= 1.0;
        }

        *sec = (time_t)intpart;
        err = intpart - (double)*sec;
        if (err <= -1.0 || err >= 1.0) {
            error_time_t_overflow();
            return -1;
        }

        floatpart *= denominator;
        *numerator = (long)floatpart;
        return 0;
    }
    else {
        *sec = _PyLong_AsTime_t(obj);
        if (*sec == (time_t)-1 && PyErr_Occurred())
            return -1;
        *numerator = 0;
        return 0;
    }
}

int
_PyTime_ObjectToTime_t(PyObject *obj, time_t *sec)
{
    if (PyFloat_Check(obj)) {
        double d, intpart, err;

        d = PyFloat_AsDouble(obj);
        (void)modf(d, &intpart);

        *sec = (time_t)intpart;
        err = intpart - (double)*sec;
        if (err <= -1.0 || err >= 1.0) {
            error_time_t_overflow();
            return -1;
        }
        return 0;
    }
    else {
        *sec = _PyLong_AsTime_t(obj);
        if (*sec == (time_t)-1 && PyErr_Occurred())
            return -1;
        return 0;
    }
}

int
_PyTime_ObjectToTimespec(PyObject *obj, time_t *sec, long *nsec)
{
    return _PyTime_ObjectToDenominator(obj, sec, nsec, 1e9);
}

int
_PyTime_ObjectToTimeval(PyObject *obj, time_t *sec, long *usec)
{
    return _PyTime_ObjectToDenominator(obj, sec, usec, 1e6);
}

void
_PyTime_Init()
{
    /* Do nothing.  Needed to force linking. */
}