python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Python/pytime.c

@@ -0,0 +1,854 @@
+#include "Python.h"
+#ifdef MS_WINDOWS
+#include <windows.h>
+#endif
+
+#if defined(__APPLE__)
+#include <mach/mach_time.h>   /* mach_absolute_time(), mach_timebase_info() */
+#endif
+
+#define _PyTime_check_mul_overflow(a, b) \
+    (assert(b > 0), \
+     (_PyTime_t)(a) < _PyTime_MIN / (_PyTime_t)(b) \
+     || _PyTime_MAX / (_PyTime_t)(b) < (_PyTime_t)(a))
+
+/* To millisecond (10^-3) */
+#define SEC_TO_MS 1000
+
+/* To microseconds (10^-6) */
+#define MS_TO_US 1000
+#define SEC_TO_US (SEC_TO_MS * MS_TO_US)
+
+/* To nanoseconds (10^-9) */
+#define US_TO_NS 1000
+#define MS_TO_NS (MS_TO_US * US_TO_NS)
+#define SEC_TO_NS (SEC_TO_MS * MS_TO_NS)
+
+/* Conversion from nanoseconds */
+#define NS_TO_MS (1000 * 1000)
+#define NS_TO_US (1000)
+
+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 SIZEOF_TIME_T == SIZEOF_LONG_LONG
+    long long val;
+    val = PyLong_AsLongLong(obj);
+#else
+    long val;
+    Py_BUILD_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 SIZEOF_TIME_T == SIZEOF_LONG_LONG
+    return PyLong_FromLongLong((long long)t);
+#else
+    Py_BUILD_ASSERT(sizeof(time_t) <= sizeof(long));
+    return PyLong_FromLong((long)t);
+#endif
+}
+
+/* Round to nearest with ties going to nearest even integer
+   (_PyTime_ROUND_HALF_EVEN) */
+static double
+_PyTime_RoundHalfEven(double x)
+{
+    double rounded = round(x);
+    if (fabs(x-rounded) == 0.5)
+        /* halfway case: round to even */
+        rounded = 2.0*round(x/2.0);
+    return rounded;
+}
+
+static double
+_PyTime_Round(double x, _PyTime_round_t round)
+{
+    /* volatile avoids optimization changing how numbers are rounded */
+    volatile double d;
+
+    d = x;
+    if (round == _PyTime_ROUND_HALF_EVEN){
+        d = _PyTime_RoundHalfEven(d);
+    }
+    else if (round == _PyTime_ROUND_CEILING){
+        d = ceil(d);
+    }
+    else if (round == _PyTime_ROUND_FLOOR) {
+        d = floor(d);
+    }
+    else {
+        assert(round == _PyTime_ROUND_UP);
+        d = (d >= 0.0) ? ceil(d) : floor(d);
+    }
+    return d;
+}
+
+static int
+_PyTime_DoubleToDenominator(double d, time_t *sec, long *numerator,
+                            double denominator, _PyTime_round_t round)
+{
+    double intpart;
+    /* volatile avoids optimization changing how numbers are rounded */
+    volatile double floatpart;
+
+    floatpart = modf(d, &intpart);
+
+    floatpart *= denominator;
+    floatpart = _PyTime_Round(floatpart, round);
+    if (floatpart >= denominator) {
+        floatpart -= denominator;
+        intpart += 1.0;
+    }
+    else if (floatpart < 0) {
+        floatpart += denominator;
+        intpart -= 1.0;
+    }
+    assert(0.0 <= floatpart && floatpart < denominator);
+
+    if (!_Py_InIntegralTypeRange(time_t, intpart)) {
+        error_time_t_overflow();
+        return -1;
+    }
+    *sec = (time_t)intpart;
+    *numerator = (long)floatpart;
+
+    return 0;
+}
+
+static int
+_PyTime_ObjectToDenominator(PyObject *obj, time_t *sec, long *numerator,
+                            double denominator, _PyTime_round_t round)
+{
+    assert(denominator <= (double)LONG_MAX);
+
+    if (PyFloat_Check(obj)) {
+        double d = PyFloat_AsDouble(obj);
+        if (Py_IS_NAN(d)) {
+            *numerator = 0;
+            PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
+            return -1;
+        }
+        return _PyTime_DoubleToDenominator(d, sec, numerator,
+                                           denominator, round);
+    }
+    else {
+        *sec = _PyLong_AsTime_t(obj);
+        *numerator = 0;
+        if (*sec == (time_t)-1 && PyErr_Occurred())
+            return -1;
+        return 0;
+    }
+}
+
+int
+_PyTime_ObjectToTime_t(PyObject *obj, time_t *sec, _PyTime_round_t round)
+{
+    if (PyFloat_Check(obj)) {
+        double intpart;
+        /* volatile avoids optimization changing how numbers are rounded */
+        volatile double d;
+
+        d = PyFloat_AsDouble(obj);
+        if (Py_IS_NAN(d)) {
+            PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
+            return -1;
+        }
+
+        d = _PyTime_Round(d, round);
+        (void)modf(d, &intpart);
+
+        if (!_Py_InIntegralTypeRange(time_t, intpart)) {
+            error_time_t_overflow();
+            return -1;
+        }
+        *sec = (time_t)intpart;
+        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,
+                         _PyTime_round_t round)
+{
+    int res;
+    res = _PyTime_ObjectToDenominator(obj, sec, nsec, 1e9, round);
+    if (res == 0) {
+        assert(0 <= *nsec && *nsec < SEC_TO_NS);
+    }
+    return res;
+}
+
+int
+_PyTime_ObjectToTimeval(PyObject *obj, time_t *sec, long *usec,
+                        _PyTime_round_t round)
+{
+    int res;
+    res = _PyTime_ObjectToDenominator(obj, sec, usec, 1e6, round);
+    if (res == 0) {
+        assert(0 <= *usec && *usec < SEC_TO_US);
+    }
+    return res;
+}
+
+static void
+_PyTime_overflow(void)
+{
+    PyErr_SetString(PyExc_OverflowError,
+                    "timestamp too large to convert to C _PyTime_t");
+}
+
+_PyTime_t
+_PyTime_FromSeconds(int seconds)
+{
+    _PyTime_t t;
+    t = (_PyTime_t)seconds;
+    /* ensure that integer overflow cannot happen, int type should have 32
+       bits, whereas _PyTime_t type has at least 64 bits (SEC_TO_MS takes 30
+       bits). */
+    Py_BUILD_ASSERT(INT_MAX <= _PyTime_MAX / SEC_TO_NS);
+    Py_BUILD_ASSERT(INT_MIN >= _PyTime_MIN / SEC_TO_NS);
+    assert((t >= 0 && t <= _PyTime_MAX / SEC_TO_NS)
+           || (t < 0 && t >= _PyTime_MIN / SEC_TO_NS));
+    t *= SEC_TO_NS;
+    return t;
+}
+
+_PyTime_t
+_PyTime_FromNanoseconds(long long ns)
+{
+    _PyTime_t t;
+    Py_BUILD_ASSERT(sizeof(long long) <= sizeof(_PyTime_t));
+    t = Py_SAFE_DOWNCAST(ns, long long, _PyTime_t);
+    return t;
+}
+
+#ifdef HAVE_CLOCK_GETTIME
+static int
+_PyTime_FromTimespec(_PyTime_t *tp, struct timespec *ts, int raise)
+{
+    _PyTime_t t;
+    int res = 0;
+
+    Py_BUILD_ASSERT(sizeof(ts->tv_sec) <= sizeof(_PyTime_t));
+    t = (_PyTime_t)ts->tv_sec;
+
+    if (_PyTime_check_mul_overflow(t, SEC_TO_NS)) {
+        if (raise)
+            _PyTime_overflow();
+        res = -1;
+    }
+    t = t * SEC_TO_NS;
+
+    t += ts->tv_nsec;
+
+    *tp = t;
+    return res;
+}
+#elif !defined(MS_WINDOWS)
+static int
+_PyTime_FromTimeval(_PyTime_t *tp, struct timeval *tv, int raise)
+{
+    _PyTime_t t;
+    int res = 0;
+
+    Py_BUILD_ASSERT(sizeof(tv->tv_sec) <= sizeof(_PyTime_t));
+    t = (_PyTime_t)tv->tv_sec;
+
+    if (_PyTime_check_mul_overflow(t, SEC_TO_NS)) {
+        if (raise)
+            _PyTime_overflow();
+        res = -1;
+    }
+    t = t * SEC_TO_NS;
+
+    t += (_PyTime_t)tv->tv_usec * US_TO_NS;
+
+    *tp = t;
+    return res;
+}
+#endif
+
+static int
+_PyTime_FromFloatObject(_PyTime_t *t, double value, _PyTime_round_t round,
+                        long unit_to_ns)
+{
+    /* volatile avoids optimization changing how numbers are rounded */
+    volatile double d;
+
+    /* convert to a number of nanoseconds */
+    d = value;
+    d *= (double)unit_to_ns;
+    d = _PyTime_Round(d, round);
+
+    if (!_Py_InIntegralTypeRange(_PyTime_t, d)) {
+        _PyTime_overflow();
+        return -1;
+    }
+    *t = (_PyTime_t)d;
+    return 0;
+}
+
+static int
+_PyTime_FromObject(_PyTime_t *t, PyObject *obj, _PyTime_round_t round,
+                   long unit_to_ns)
+{
+    if (PyFloat_Check(obj)) {
+        double d;
+        d = PyFloat_AsDouble(obj);
+        if (Py_IS_NAN(d)) {
+            PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
+            return -1;
+        }
+        return _PyTime_FromFloatObject(t, d, round, unit_to_ns);
+    }
+    else {
+        long long sec;
+        Py_BUILD_ASSERT(sizeof(long long) <= sizeof(_PyTime_t));
+
+        sec = PyLong_AsLongLong(obj);
+        if (sec == -1 && PyErr_Occurred()) {
+            if (PyErr_ExceptionMatches(PyExc_OverflowError))
+                _PyTime_overflow();
+            return -1;
+        }
+
+        if (_PyTime_check_mul_overflow(sec, unit_to_ns)) {
+            _PyTime_overflow();
+            return -1;
+        }
+        *t = sec * unit_to_ns;
+        return 0;
+    }
+}
+
+int
+_PyTime_FromSecondsObject(_PyTime_t *t, PyObject *obj, _PyTime_round_t round)
+{
+    return _PyTime_FromObject(t, obj, round, SEC_TO_NS);
+}
+
+int
+_PyTime_FromMillisecondsObject(_PyTime_t *t, PyObject *obj, _PyTime_round_t round)
+{
+    return _PyTime_FromObject(t, obj, round, MS_TO_NS);
+}
+
+double
+_PyTime_AsSecondsDouble(_PyTime_t t)
+{
+    /* volatile avoids optimization changing how numbers are rounded */
+    volatile double d;
+
+    if (t % SEC_TO_NS == 0) {
+        _PyTime_t secs;
+        /* Divide using integers to avoid rounding issues on the integer part.
+           1e-9 cannot be stored exactly in IEEE 64-bit. */
+        secs = t / SEC_TO_NS;
+        d = (double)secs;
+    }
+    else {
+        d = (double)t;
+        d /= 1e9;
+    }
+    return d;
+}
+
+PyObject *
+_PyTime_AsNanosecondsObject(_PyTime_t t)
+{
+    Py_BUILD_ASSERT(sizeof(long long) >= sizeof(_PyTime_t));
+    return PyLong_FromLongLong((long long)t);
+}
+
+static _PyTime_t
+_PyTime_Divide(const _PyTime_t t, const _PyTime_t k,
+               const _PyTime_round_t round)
+{
+    assert(k > 1);
+    if (round == _PyTime_ROUND_HALF_EVEN) {
+        _PyTime_t x, r, abs_r;
+        x = t / k;
+        r = t % k;
+        abs_r = Py_ABS(r);
+        if (abs_r > k / 2 || (abs_r == k / 2 && (Py_ABS(x) & 1))) {
+            if (t >= 0)
+                x++;
+            else
+                x--;
+        }
+        return x;
+    }
+    else if (round == _PyTime_ROUND_CEILING) {
+        if (t >= 0){
+            return (t + k - 1) / k;
+        }
+        else{
+            return t / k;
+        }
+    }
+    else if (round == _PyTime_ROUND_FLOOR){
+        if (t >= 0) {
+            return t / k;
+        }
+        else{
+            return (t - (k - 1)) / k;
+        }
+    }
+    else {
+        assert(round == _PyTime_ROUND_UP);
+        if (t >= 0) {
+            return (t + k - 1) / k;
+        }
+        else {
+            return (t - (k - 1)) / k;
+        }
+    }
+}
+
+_PyTime_t
+_PyTime_AsMilliseconds(_PyTime_t t, _PyTime_round_t round)
+{
+    return _PyTime_Divide(t, NS_TO_MS, round);
+}
+
+_PyTime_t
+_PyTime_AsMicroseconds(_PyTime_t t, _PyTime_round_t round)
+{
+    return _PyTime_Divide(t, NS_TO_US, round);
+}
+
+static int
+_PyTime_AsTimeval_impl(_PyTime_t t, _PyTime_t *p_secs, int *p_us,
+                       _PyTime_round_t round)
+{
+    _PyTime_t secs, ns;
+    int usec;
+    int res = 0;
+
+    secs = t / SEC_TO_NS;
+    ns = t % SEC_TO_NS;
+
+    usec = (int)_PyTime_Divide(ns, US_TO_NS, round);
+    if (usec < 0) {
+        usec += SEC_TO_US;
+        if (secs != _PyTime_MIN)
+            secs -= 1;
+        else
+            res = -1;
+    }
+    else if (usec >= SEC_TO_US) {
+        usec -= SEC_TO_US;
+        if (secs != _PyTime_MAX)
+            secs += 1;
+        else
+            res = -1;
+    }
+    assert(0 <= usec && usec < SEC_TO_US);
+
+    *p_secs = secs;
+    *p_us = usec;
+
+    return res;
+}
+
+static int
+_PyTime_AsTimevalStruct_impl(_PyTime_t t, struct timeval *tv,
+                             _PyTime_round_t round, int raise)
+{
+    _PyTime_t secs, secs2;
+    int us;
+    int res;
+
+    res = _PyTime_AsTimeval_impl(t, &secs, &us, round);
+
+#ifdef MS_WINDOWS
+    tv->tv_sec = (long)secs;
+#else
+    tv->tv_sec = secs;
+#endif
+    tv->tv_usec = us;
+
+    secs2 = (_PyTime_t)tv->tv_sec;
+    if (res < 0 || secs2 != secs) {
+        if (raise)
+            error_time_t_overflow();
+        return -1;
+    }
+    return 0;
+}
+
+int
+_PyTime_AsTimeval(_PyTime_t t, struct timeval *tv, _PyTime_round_t round)
+{
+    return _PyTime_AsTimevalStruct_impl(t, tv, round, 1);
+}
+
+int
+_PyTime_AsTimeval_noraise(_PyTime_t t, struct timeval *tv, _PyTime_round_t round)
+{
+    return _PyTime_AsTimevalStruct_impl(t, tv, round, 0);
+}
+
+int
+_PyTime_AsTimevalTime_t(_PyTime_t t, time_t *p_secs, int *us,
+                        _PyTime_round_t round)
+{
+    _PyTime_t secs;
+    int res;
+
+    res = _PyTime_AsTimeval_impl(t, &secs, us, round);
+
+    *p_secs = secs;
+
+    if (res < 0 || (_PyTime_t)*p_secs != secs) {
+        error_time_t_overflow();
+        return -1;
+    }
+    return 0;
+}
+
+
+#if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_KQUEUE)
+int
+_PyTime_AsTimespec(_PyTime_t t, struct timespec *ts)
+{
+    _PyTime_t secs, nsec;
+
+    secs = t / SEC_TO_NS;
+    nsec = t % SEC_TO_NS;
+    if (nsec < 0) {
+        nsec += SEC_TO_NS;
+        secs -= 1;
+    }
+    ts->tv_sec = (time_t)secs;
+    assert(0 <= nsec && nsec < SEC_TO_NS);
+    ts->tv_nsec = nsec;
+
+    if ((_PyTime_t)ts->tv_sec != secs) {
+        error_time_t_overflow();
+        return -1;
+    }
+    return 0;
+}
+#endif
+
+static int
+pygettimeofday(_PyTime_t *tp, _Py_clock_info_t *info, int raise)
+{
+#ifdef MS_WINDOWS
+    FILETIME system_time;
+    ULARGE_INTEGER large;
+
+    assert(info == NULL || raise);
+
+    GetSystemTimeAsFileTime(&system_time);
+    large.u.LowPart = system_time.dwLowDateTime;
+    large.u.HighPart = system_time.dwHighDateTime;
+    /* 11,644,473,600,000,000,000: number of nanoseconds between
+       the 1st january 1601 and the 1st january 1970 (369 years + 89 leap
+       days). */
+    *tp = large.QuadPart * 100 - 11644473600000000000;
+    if (info) {
+        DWORD timeAdjustment, timeIncrement;
+        BOOL isTimeAdjustmentDisabled, ok;
+
+        info->implementation = "GetSystemTimeAsFileTime()";
+        info->monotonic = 0;
+        ok = GetSystemTimeAdjustment(&timeAdjustment, &timeIncrement,
+                                     &isTimeAdjustmentDisabled);
+        if (!ok) {
+            PyErr_SetFromWindowsErr(0);
+            return -1;
+        }
+        info->resolution = timeIncrement * 1e-7;
+        info->adjustable = 1;
+    }
+
+#else   /* MS_WINDOWS */
+    int err;
+#ifdef HAVE_CLOCK_GETTIME
+    struct timespec ts;
+#else
+    struct timeval tv;
+#endif
+
+    assert(info == NULL || raise);
+
+#ifdef HAVE_CLOCK_GETTIME
+    err = clock_gettime(CLOCK_REALTIME, &ts);
+    if (err) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    if (_PyTime_FromTimespec(tp, &ts, raise) < 0)
+        return -1;
+
+    if (info) {
+        struct timespec res;
+        info->implementation = "clock_gettime(CLOCK_REALTIME)";
+        info->monotonic = 0;
+        info->adjustable = 1;
+        if (clock_getres(CLOCK_REALTIME, &res) == 0)
+            info->resolution = res.tv_sec + res.tv_nsec * 1e-9;
+        else
+            info->resolution = 1e-9;
+    }
+#else   /* HAVE_CLOCK_GETTIME */
+
+     /* test gettimeofday() */
+#ifdef GETTIMEOFDAY_NO_TZ
+    err = gettimeofday(&tv);
+#else
+    err = gettimeofday(&tv, (struct timezone *)NULL);
+#endif
+    if (err) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    if (_PyTime_FromTimeval(tp, &tv, raise) < 0)
+        return -1;
+
+    if (info) {
+        info->implementation = "gettimeofday()";
+        info->resolution = 1e-6;
+        info->monotonic = 0;
+        info->adjustable = 1;
+    }
+#endif   /* !HAVE_CLOCK_GETTIME */
+#endif   /* !MS_WINDOWS */
+    return 0;
+}
+
+_PyTime_t
+_PyTime_GetSystemClock(void)
+{
+    _PyTime_t t;
+    if (pygettimeofday(&t, NULL, 0) < 0) {
+        /* should not happen, _PyTime_Init() checked the clock at startup */
+        assert(0);
+
+        /* use a fixed value instead of a random value from the stack */
+        t = 0;
+    }
+    return t;
+}
+
+int
+_PyTime_GetSystemClockWithInfo(_PyTime_t *t, _Py_clock_info_t *info)
+{
+    return pygettimeofday(t, info, 1);
+}
+
+static int
+pymonotonic(_PyTime_t *tp, _Py_clock_info_t *info, int raise)
+{
+#if defined(MS_WINDOWS)
+    ULONGLONG ticks;
+    _PyTime_t t;
+
+    assert(info == NULL || raise);
+
+    ticks = GetTickCount64();
+    Py_BUILD_ASSERT(sizeof(ticks) <= sizeof(_PyTime_t));
+    t = (_PyTime_t)ticks;
+
+    if (_PyTime_check_mul_overflow(t, MS_TO_NS)) {
+        if (raise) {
+            _PyTime_overflow();
+            return -1;
+        }
+        /* Hello, time traveler! */
+        assert(0);
+    }
+    *tp = t * MS_TO_NS;
+
+    if (info) {
+        DWORD timeAdjustment, timeIncrement;
+        BOOL isTimeAdjustmentDisabled, ok;
+        info->implementation = "GetTickCount64()";
+        info->monotonic = 1;
+        ok = GetSystemTimeAdjustment(&timeAdjustment, &timeIncrement,
+                                     &isTimeAdjustmentDisabled);
+        if (!ok) {
+            PyErr_SetFromWindowsErr(0);
+            return -1;
+        }
+        info->resolution = timeIncrement * 1e-7;
+        info->adjustable = 0;
+    }
+
+#elif defined(__APPLE__)
+    static mach_timebase_info_data_t timebase;
+    uint64_t time;
+
+    if (timebase.denom == 0) {
+        /* According to the Technical Q&A QA1398, mach_timebase_info() cannot
+           fail: https://developer.apple.com/library/mac/#qa/qa1398/ */
+        (void)mach_timebase_info(&timebase);
+    }
+
+    time = mach_absolute_time();
+
+    /* apply timebase factor */
+    time *= timebase.numer;
+    time /= timebase.denom;
+
+    *tp = time;
+
+    if (info) {
+        info->implementation = "mach_absolute_time()";
+        info->resolution = (double)timebase.numer / timebase.denom * 1e-9;
+        info->monotonic = 1;
+        info->adjustable = 0;
+    }
+
+#else
+    struct timespec ts;
+#ifdef CLOCK_HIGHRES
+    const clockid_t clk_id = CLOCK_HIGHRES;
+    const char *implementation = "clock_gettime(CLOCK_HIGHRES)";
+#else
+    const clockid_t clk_id = CLOCK_MONOTONIC;
+    const char *implementation = "clock_gettime(CLOCK_MONOTONIC)";
+#endif
+
+    assert(info == NULL || raise);
+
+    if (clock_gettime(clk_id, &ts) != 0) {
+        if (raise) {
+            PyErr_SetFromErrno(PyExc_OSError);
+            return -1;
+        }
+        return -1;
+    }
+
+    if (info) {
+        struct timespec res;
+        info->monotonic = 1;
+        info->implementation = implementation;
+        info->adjustable = 0;
+        if (clock_getres(clk_id, &res) != 0) {
+            PyErr_SetFromErrno(PyExc_OSError);
+            return -1;
+        }
+        info->resolution = res.tv_sec + res.tv_nsec * 1e-9;
+    }
+    if (_PyTime_FromTimespec(tp, &ts, raise) < 0)
+        return -1;
+#endif
+    return 0;
+}
+
+_PyTime_t
+_PyTime_GetMonotonicClock(void)
+{
+    _PyTime_t t;
+    if (pymonotonic(&t, NULL, 0) < 0) {
+        /* should not happen, _PyTime_Init() checked that monotonic clock at
+           startup */
+        assert(0);
+
+        /* use a fixed value instead of a random value from the stack */
+        t = 0;
+    }
+    return t;
+}
+
+int
+_PyTime_GetMonotonicClockWithInfo(_PyTime_t *tp, _Py_clock_info_t *info)
+{
+    return pymonotonic(tp, info, 1);
+}
+
+int
+_PyTime_Init(void)
+{
+    _PyTime_t t;
+
+    /* ensure that the system clock works */
+    if (_PyTime_GetSystemClockWithInfo(&t, NULL) < 0)
+        return -1;
+
+    /* ensure that the operating system provides a monotonic clock */
+    if (_PyTime_GetMonotonicClockWithInfo(&t, NULL) < 0)
+        return -1;
+
+    return 0;
+}
+
+int
+_PyTime_localtime(time_t t, struct tm *tm)
+{
+#ifdef MS_WINDOWS
+    int error;
+
+    error = localtime_s(tm, &t);
+    if (error != 0) {
+        errno = error;
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return 0;
+#else /* !MS_WINDOWS */
+    if (localtime_r(&t, tm) == NULL) {
+#ifdef EINVAL
+        if (errno == 0)
+            errno = EINVAL;
+#endif
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return 0;
+#endif /* MS_WINDOWS */
+}
+
+int
+_PyTime_gmtime(time_t t, struct tm *tm)
+{
+#ifdef MS_WINDOWS
+    int error;
+
+    error = gmtime_s(tm, &t);
+    if (error != 0) {
+        errno = error;
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return 0;
+#else /* !MS_WINDOWS */
+    if (gmtime_r(&t, tm) == NULL) {
+#ifdef EINVAL
+        if (errno == 0)
+            errno = EINVAL;
+#endif
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return 0;
+#endif /* MS_WINDOWS */
+}