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cpython/Python/pytime.c

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#include "Python.h"
#include "pycore_time.h" // PyTime_t
#include <time.h> // gmtime_r()
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h> // gettimeofday()
#endif
#ifdef MS_WINDOWS
# include <winsock2.h> // struct timeval
#endif
#if defined(__APPLE__)
# include <mach/mach_time.h> // mach_absolute_time(), mach_timebase_info()
#if defined(__APPLE__) && defined(__has_builtin)
# if __has_builtin(__builtin_available)
# define HAVE_CLOCK_GETTIME_RUNTIME __builtin_available(macOS 10.12, iOS 10.0, tvOS 10.0, watchOS 3.0, *)
# endif
#endif
#endif
/* 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)
#define NS_TO_100NS (100)
#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
# define PY_TIME_T_MAX LLONG_MAX
# define PY_TIME_T_MIN LLONG_MIN
#elif SIZEOF_TIME_T == SIZEOF_LONG
# define PY_TIME_T_MAX LONG_MAX
# define PY_TIME_T_MIN LONG_MIN
#else
# error "unsupported time_t size"
#endif
#if PY_TIME_T_MAX + PY_TIME_T_MIN != -1
# error "time_t is not a two's complement integer type"
#endif
#if PyTime_MIN + PyTime_MAX != -1
# error "PyTime_t is not a two's complement integer type"
#endif
#ifdef MS_WINDOWS
static _PyTimeFraction py_qpc_base = {0, 0};
// Forward declaration
static int py_win_perf_counter_frequency(_PyTimeFraction *base, int raise_exc);
#endif
static PyTime_t
_PyTime_GCD(PyTime_t x, PyTime_t y)
{
// Euclidean algorithm
assert(x >= 1);
assert(y >= 1);
while (y != 0) {
PyTime_t tmp = y;
y = x % y;
x = tmp;
}
assert(x >= 1);
return x;
}
int
_PyTimeFraction_Set(_PyTimeFraction *frac, PyTime_t numer, PyTime_t denom)
{
if (numer < 1 || denom < 1) {
return -1;
}
PyTime_t gcd = _PyTime_GCD(numer, denom);
frac->numer = numer / gcd;
frac->denom = denom / gcd;
return 0;
}
double
_PyTimeFraction_Resolution(const _PyTimeFraction *frac)
{
return (double)frac->numer / (double)frac->denom / 1e9;
}
static void
pytime_time_t_overflow(void)
{
PyErr_SetString(PyExc_OverflowError,
"timestamp out of range for platform time_t");
}
static void
pytime_overflow(void)
{
PyErr_SetString(PyExc_OverflowError,
"timestamp too large to convert to C PyTime_t");
}
// Compute t1 + t2. Clamp to [PyTime_MIN; PyTime_MAX] on overflow.
static inline int
pytime_add(PyTime_t *t1, PyTime_t t2)
{
if (t2 > 0 && *t1 > PyTime_MAX - t2) {
*t1 = PyTime_MAX;
return -1;
}
else if (t2 < 0 && *t1 < PyTime_MIN - t2) {
*t1 = PyTime_MIN;
return -1;
}
else {
*t1 += t2;
return 0;
}
}
PyTime_t
_PyTime_Add(PyTime_t t1, PyTime_t t2)
{
(void)pytime_add(&t1, t2);
return t1;
}
static inline int
pytime_mul_check_overflow(PyTime_t a, PyTime_t b)
{
if (b != 0) {
assert(b > 0);
return ((a < PyTime_MIN / b) || (PyTime_MAX / b < a));
}
else {
return 0;
}
}
// Compute t * k. Clamp to [PyTime_MIN; PyTime_MAX] on overflow.
static inline int
pytime_mul(PyTime_t *t, PyTime_t k)
{
assert(k >= 0);
if (pytime_mul_check_overflow(*t, k)) {
*t = (*t >= 0) ? PyTime_MAX : PyTime_MIN;
return -1;
}
else {
*t *= k;
return 0;
}
}
// Compute t * k. Clamp to [PyTime_MIN; PyTime_MAX] on overflow.
static inline PyTime_t
_PyTime_Mul(PyTime_t t, PyTime_t k)
{
(void)pytime_mul(&t, k);
return t;
}
PyTime_t
_PyTimeFraction_Mul(PyTime_t ticks, const _PyTimeFraction *frac)
{
const PyTime_t mul = frac->numer;
const PyTime_t div = frac->denom;
if (div == 1) {
// Fast-path taken by mach_absolute_time() with 1/1 time base.
return _PyTime_Mul(ticks, mul);
}
/* Compute (ticks * mul / div) in two parts to reduce the risk of integer
overflow: compute the integer part, and then the remaining part.
(ticks * mul) / div == (ticks / div) * mul + (ticks % div) * mul / div
*/
PyTime_t intpart, remaining;
intpart = ticks / div;
ticks %= div;
remaining = _PyTime_Mul(ticks, mul) / div;
// intpart * mul + remaining
return _PyTime_Add(_PyTime_Mul(intpart, mul), remaining);
}
time_t
_PyLong_AsTime_t(PyObject *obj)
{
#if SIZEOF_TIME_T == SIZEOF_LONG_LONG
long long val = PyLong_AsLongLong(obj);
#elif SIZEOF_TIME_T <= SIZEOF_LONG
long val = PyLong_AsLong(obj);
#else
# error "unsupported time_t size"
#endif
if (val == -1 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
pytime_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);
#elif SIZEOF_TIME_T <= SIZEOF_LONG
return PyLong_FromLong((long)t);
#else
# error "unsupported time_t size"
#endif
}
// Convert PyTime_t to time_t.
// Return 0 on success. Return -1 and clamp the value on overflow.
static int
_PyTime_AsTime_t(PyTime_t t, time_t *t2)
{
#if SIZEOF_TIME_T < _SIZEOF_PYTIME_T
if ((PyTime_t)PY_TIME_T_MAX < t) {
*t2 = PY_TIME_T_MAX;
return -1;
}
if (t < (PyTime_t)PY_TIME_T_MIN) {
*t2 = PY_TIME_T_MIN;
return -1;
}
#endif
*t2 = (time_t)t;
return 0;
}
#ifdef MS_WINDOWS
// Convert PyTime_t to long.
// Return 0 on success. Return -1 and clamp the value on overflow.
static int
_PyTime_AsCLong(PyTime_t t, long *t2)
{
#if SIZEOF_LONG < _SIZEOF_PYTIME_T
if ((PyTime_t)LONG_MAX < t) {
*t2 = LONG_MAX;
return -1;
}
if (t < (PyTime_t)LONG_MIN) {
*t2 = LONG_MIN;
return -1;
}
#endif
*t2 = (long)t;
return 0;
}
#endif
/* Round to nearest with ties going to nearest even integer
(_PyTime_ROUND_HALF_EVEN) */
static double
pytime_round_half_even(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_round_half_even(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_double_to_denominator(double d, time_t *sec, long *numerator,
long idenominator, _PyTime_round_t round)
{
double denominator = (double)idenominator;
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);
/*
Conversion of an out-of-range value to time_t gives undefined behaviour
(C99 §6.3.1.4p1), so we must guard against it. However, checking that
`intpart` is in range is delicate: the obvious expression `intpart <=
PY_TIME_T_MAX` will first convert the value `PY_TIME_T_MAX` to a double,
potentially changing its value and leading to us failing to catch some
UB-inducing values. The code below works correctly under the mild
assumption that time_t is a two's complement integer type with no trap
representation, and that `PY_TIME_T_MIN` is within the representable
range of a C double.
Note: we want the `if` condition below to be true for NaNs; therefore,
resist any temptation to simplify by applying De Morgan's laws.
*/
if (!((double)PY_TIME_T_MIN <= intpart && intpart < -(double)PY_TIME_T_MIN)) {
pytime_time_t_overflow();
return -1;
}
*sec = (time_t)intpart;
*numerator = (long)floatpart;
assert(0 <= *numerator && *numerator < idenominator);
return 0;
}
static int
pytime_object_to_denominator(PyObject *obj, time_t *sec, long *numerator,
long denominator, _PyTime_round_t round)
{
assert(denominator >= 1);
if (PyFloat_Check(obj)) {
double d = PyFloat_AsDouble(obj);
if (isnan(d)) {
*numerator = 0;
PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
return -1;
}
return pytime_double_to_denominator(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 (isnan(d)) {
PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
return -1;
}
d = pytime_round(d, round);
(void)modf(d, &intpart);
/* See comments in pytime_double_to_denominator */
if (!((double)PY_TIME_T_MIN <= intpart && intpart < -(double)PY_TIME_T_MIN)) {
pytime_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)
{
return pytime_object_to_denominator(obj, sec, nsec, SEC_TO_NS, round);
}
int
_PyTime_ObjectToTimeval(PyObject *obj, time_t *sec, long *usec,
_PyTime_round_t round)
{
return pytime_object_to_denominator(obj, sec, usec, SEC_TO_US, round);
}
PyTime_t
_PyTime_FromSeconds(int seconds)
{
/* ensure that integer overflow cannot happen, int type should have 32
bits, whereas PyTime_t type has at least 64 bits (SEC_TO_NS takes 30
bits). */
static_assert(INT_MAX <= PyTime_MAX / SEC_TO_NS, "PyTime_t overflow");
static_assert(INT_MIN >= PyTime_MIN / SEC_TO_NS, "PyTime_t underflow");
PyTime_t t = (PyTime_t)seconds;
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_FromMicrosecondsClamp(PyTime_t us)
{
PyTime_t ns = _PyTime_Mul(us, US_TO_NS);
return ns;
}
int
_PyTime_FromLong(PyTime_t *tp, PyObject *obj)
{
if (!PyLong_Check(obj)) {
PyErr_Format(PyExc_TypeError, "expect int, got %s",
Py_TYPE(obj)->tp_name);
return -1;
}
static_assert(sizeof(long long) == sizeof(PyTime_t),
"PyTime_t is not long long");
long long nsec = PyLong_AsLongLong(obj);
if (nsec == -1 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
pytime_overflow();
}
return -1;
}
PyTime_t t = (PyTime_t)nsec;
*tp = t;
return 0;
}
#ifdef HAVE_CLOCK_GETTIME
static int
pytime_fromtimespec(PyTime_t *tp, const struct timespec *ts, int raise_exc)
{
PyTime_t t, tv_nsec;
static_assert(sizeof(ts->tv_sec) <= sizeof(PyTime_t),
"timespec.tv_sec is larger than PyTime_t");
t = (PyTime_t)ts->tv_sec;
int res1 = pytime_mul(&t, SEC_TO_NS);
tv_nsec = ts->tv_nsec;
int res2 = pytime_add(&t, tv_nsec);
*tp = t;
if (raise_exc && (res1 < 0 || res2 < 0)) {
pytime_overflow();
return -1;
}
return 0;
}
int
_PyTime_FromTimespec(PyTime_t *tp, const struct timespec *ts)
{
return pytime_fromtimespec(tp, ts, 1);
}
#endif
#ifndef MS_WINDOWS
static int
pytime_fromtimeval(PyTime_t *tp, struct timeval *tv, int raise_exc)
{
static_assert(sizeof(tv->tv_sec) <= sizeof(PyTime_t),
"timeval.tv_sec is larger than PyTime_t");
PyTime_t t = (PyTime_t)tv->tv_sec;
int res1 = pytime_mul(&t, SEC_TO_NS);
PyTime_t usec = (PyTime_t)tv->tv_usec * US_TO_NS;
int res2 = pytime_add(&t, usec);
*tp = t;
if (raise_exc && (res1 < 0 || res2 < 0)) {
pytime_overflow();
return -1;
}
return 0;
}
int
_PyTime_FromTimeval(PyTime_t *tp, struct timeval *tv)
{
return pytime_fromtimeval(tp, tv, 1);
}
#endif
static int
pytime_from_double(PyTime_t *tp, 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);
/* See comments in pytime_double_to_denominator */
if (!((double)PyTime_MIN <= d && d < -(double)PyTime_MIN)) {
pytime_time_t_overflow();
*tp = 0;
return -1;
}
PyTime_t ns = (PyTime_t)d;
*tp = ns;
return 0;
}
static int
pytime_from_object(PyTime_t *tp, PyObject *obj, _PyTime_round_t round,
long unit_to_ns)
{
if (PyFloat_Check(obj)) {
double d;
d = PyFloat_AsDouble(obj);
if (isnan(d)) {
PyErr_SetString(PyExc_ValueError, "Invalid value NaN (not a number)");
return -1;
}
return pytime_from_double(tp, d, round, unit_to_ns);
}
else {
long long sec = PyLong_AsLongLong(obj);
if (sec == -1 && PyErr_Occurred()) {
if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
pytime_overflow();
}
return -1;
}
static_assert(sizeof(long long) <= sizeof(PyTime_t),
"PyTime_t is smaller than long long");
PyTime_t ns = (PyTime_t)sec;
if (pytime_mul(&ns, unit_to_ns) < 0) {
pytime_overflow();
return -1;
}
*tp = ns;
return 0;
}
}
int
_PyTime_FromSecondsObject(PyTime_t *tp, PyObject *obj, _PyTime_round_t round)
{
return pytime_from_object(tp, obj, round, SEC_TO_NS);
}
int
_PyTime_FromMillisecondsObject(PyTime_t *tp, PyObject *obj, _PyTime_round_t round)
{
return pytime_from_object(tp, obj, round, MS_TO_NS);
}
double
PyTime_AsSecondsDouble(PyTime_t ns)
{
/* volatile avoids optimization changing how numbers are rounded */
volatile double d;
if (ns % SEC_TO_NS == 0) {
/* Divide using integers to avoid rounding issues on the integer part.
1e-9 cannot be stored exactly in IEEE 64-bit. */
PyTime_t secs = ns / SEC_TO_NS;
d = (double)secs;
}
else {
d = (double)ns;
d /= 1e9;
}
return d;
}
PyObject *
_PyTime_AsLong(PyTime_t ns)
{
static_assert(sizeof(long long) >= sizeof(PyTime_t),
"PyTime_t is larger than long long");
return PyLong_FromLongLong((long long)ns);
}
int
_PyTime_FromSecondsDouble(double seconds, _PyTime_round_t round, PyTime_t *result)
{
return pytime_from_double(result, seconds, round, SEC_TO_NS);
}
static PyTime_t
pytime_divide_round_up(const PyTime_t t, const PyTime_t k)
{
assert(k > 1);
if (t >= 0) {
// Don't use (t + k - 1) / k to avoid integer overflow
// if t is equal to PyTime_MAX
PyTime_t q = t / k;
if (t % k) {
q += 1;
}
return q;
}
else {
// Don't use (t - (k - 1)) / k to avoid integer overflow
// if t is equals to PyTime_MIN.
PyTime_t q = t / k;
if (t % k) {
q -= 1;
}
return q;
}
}
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 = t / k;
PyTime_t r = t % k;
PyTime_t 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 pytime_divide_round_up(t, k);
}
else {
return t / k;
}
}
else if (round == _PyTime_ROUND_FLOOR){
if (t >= 0) {
return t / k;
}
else {
return pytime_divide_round_up(t, k);
}
}
else {
assert(round == _PyTime_ROUND_UP);
return pytime_divide_round_up(t, k);
}
}
// Compute (t / k, t % k) in (pq, pr).
// Make sure that 0 <= pr < k.
// Return 0 on success.
// Return -1 on underflow and store (PyTime_MIN, 0) in (pq, pr).
static int
pytime_divmod(const PyTime_t t, const PyTime_t k,
PyTime_t *pq, PyTime_t *pr)
{
assert(k > 1);
PyTime_t q = t / k;
PyTime_t r = t % k;
if (r < 0) {
if (q == PyTime_MIN) {
*pq = PyTime_MIN;
*pr = 0;
return -1;
}
r += k;
q -= 1;
}
assert(0 <= r && r < k);
*pq = q;
*pr = r;
return 0;
}
#ifdef MS_WINDOWS
PyTime_t
_PyTime_As100Nanoseconds(PyTime_t ns, _PyTime_round_t round)
{
return pytime_divide(ns, NS_TO_100NS, round);
}
#endif
PyTime_t
_PyTime_AsMicroseconds(PyTime_t ns, _PyTime_round_t round)
{
return pytime_divide(ns, NS_TO_US, round);
}
PyTime_t
_PyTime_AsMilliseconds(PyTime_t ns, _PyTime_round_t round)
{
return pytime_divide(ns, NS_TO_MS, round);
}
static int
pytime_as_timeval(PyTime_t ns, PyTime_t *ptv_sec, int *ptv_usec,
_PyTime_round_t round)
{
PyTime_t us = pytime_divide(ns, US_TO_NS, round);
PyTime_t tv_sec, tv_usec;
int res = pytime_divmod(us, SEC_TO_US, &tv_sec, &tv_usec);
*ptv_sec = tv_sec;
*ptv_usec = (int)tv_usec;
return res;
}
static int
pytime_as_timeval_struct(PyTime_t t, struct timeval *tv,
_PyTime_round_t round, int raise_exc)
{
PyTime_t tv_sec;
int tv_usec;
int res = pytime_as_timeval(t, &tv_sec, &tv_usec, round);
int res2;
#ifdef MS_WINDOWS
// On Windows, timeval.tv_sec type is long
res2 = _PyTime_AsCLong(tv_sec, &tv->tv_sec);
#else
res2 = _PyTime_AsTime_t(tv_sec, &tv->tv_sec);
#endif
if (res2 < 0) {
tv_usec = 0;
}
tv->tv_usec = tv_usec;
if (raise_exc && (res < 0 || res2 < 0)) {
pytime_time_t_overflow();
return -1;
}
return 0;
}
int
_PyTime_AsTimeval(PyTime_t t, struct timeval *tv, _PyTime_round_t round)
{
return pytime_as_timeval_struct(t, tv, round, 1);
}
void
_PyTime_AsTimeval_clamp(PyTime_t t, struct timeval *tv, _PyTime_round_t round)
{
(void)pytime_as_timeval_struct(t, tv, round, 0);
}
int
_PyTime_AsTimevalTime_t(PyTime_t t, time_t *p_secs, int *us,
_PyTime_round_t round)
{
PyTime_t secs;
if (pytime_as_timeval(t, &secs, us, round) < 0) {
pytime_time_t_overflow();
return -1;
}
if (_PyTime_AsTime_t(secs, p_secs) < 0) {
pytime_time_t_overflow();
return -1;
}
return 0;
}
#if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_KQUEUE)
static int
pytime_as_timespec(PyTime_t ns, struct timespec *ts, int raise_exc)
{
PyTime_t tv_sec, tv_nsec;
int res = pytime_divmod(ns, SEC_TO_NS, &tv_sec, &tv_nsec);
int res2 = _PyTime_AsTime_t(tv_sec, &ts->tv_sec);
if (res2 < 0) {
tv_nsec = 0;
}
ts->tv_nsec = tv_nsec;
if (raise_exc && (res < 0 || res2 < 0)) {
pytime_time_t_overflow();
return -1;
}
return 0;
}
void
_PyTime_AsTimespec_clamp(PyTime_t t, struct timespec *ts)
{
(void)pytime_as_timespec(t, ts, 0);
}
int
_PyTime_AsTimespec(PyTime_t t, struct timespec *ts)
{
return pytime_as_timespec(t, ts, 1);
}
#endif
// N.B. If raise_exc=0, this may be called without the GIL.
static int
py_get_system_clock(PyTime_t *tp, _Py_clock_info_t *info, int raise_exc)
{
assert(info == NULL || raise_exc);
if (raise_exc) {
// raise_exc requires to hold the GIL
assert(PyGILState_Check());
}
#ifdef MS_WINDOWS
FILETIME system_time;
ULARGE_INTEGER large;
GetSystemTimePreciseAsFileTime(&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). */
PyTime_t ns = large.QuadPart * 100 - 11644473600000000000;
*tp = ns;
if (info) {
// GetSystemTimePreciseAsFileTime() is implemented using
// QueryPerformanceCounter() internally.
if (py_qpc_base.denom == 0) {
if (py_win_perf_counter_frequency(&py_qpc_base, raise_exc) < 0) {
return -1;
}
}
info->implementation = "GetSystemTimePreciseAsFileTime()";
info->monotonic = 0;
info->resolution = _PyTimeFraction_Resolution(&py_qpc_base);
info->adjustable = 1;
}
#else /* MS_WINDOWS */
int err;
#if defined(HAVE_CLOCK_GETTIME)
struct timespec ts;
#endif
#if !defined(HAVE_CLOCK_GETTIME) || defined(__APPLE__)
struct timeval tv;
#endif
#ifdef HAVE_CLOCK_GETTIME
#ifdef HAVE_CLOCK_GETTIME_RUNTIME
if (HAVE_CLOCK_GETTIME_RUNTIME) {
#endif
err = clock_gettime(CLOCK_REALTIME, &ts);
if (err) {
if (raise_exc) {
PyErr_SetFromErrno(PyExc_OSError);
}
return -1;
}
if (pytime_fromtimespec(tp, &ts, raise_exc) < 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 = (double)res.tv_sec + (double)res.tv_nsec * 1e-9;
}
else {
info->resolution = 1e-9;
}
}
#ifdef HAVE_CLOCK_GETTIME_RUNTIME
}
else {
#endif
#endif
#if !defined(HAVE_CLOCK_GETTIME) || defined(HAVE_CLOCK_GETTIME_RUNTIME)
/* test gettimeofday() */
err = gettimeofday(&tv, (struct timezone *)NULL);
if (err) {
if (raise_exc) {
PyErr_SetFromErrno(PyExc_OSError);
}
return -1;
}
if (pytime_fromtimeval(tp, &tv, raise_exc) < 0) {
return -1;
}
if (info) {
info->implementation = "gettimeofday()";
info->resolution = 1e-6;
info->monotonic = 0;
info->adjustable = 1;
}
#if defined(HAVE_CLOCK_GETTIME_RUNTIME) && defined(HAVE_CLOCK_GETTIME)
} /* end of availability block */
#endif
#endif /* !HAVE_CLOCK_GETTIME */
#endif /* !MS_WINDOWS */
return 0;
}
int
PyTime_Time(PyTime_t *result)
{
if (py_get_system_clock(result, NULL, 1) < 0) {
*result = 0;
return -1;
}
return 0;
}
int
PyTime_TimeRaw(PyTime_t *result)
{
if (py_get_system_clock(result, NULL, 0) < 0) {
*result = 0;
return -1;
}
return 0;
}
int
_PyTime_TimeWithInfo(PyTime_t *t, _Py_clock_info_t *info)
{
return py_get_system_clock(t, info, 1);
}
#ifdef MS_WINDOWS
static int
py_win_perf_counter_frequency(_PyTimeFraction *base, int raise_exc)
{
LARGE_INTEGER freq;
// Since Windows XP, the function cannot fail.
(void)QueryPerformanceFrequency(&freq);
LONGLONG frequency = freq.QuadPart;
// Since Windows XP, frequency cannot be zero.
assert(frequency >= 1);
Py_BUILD_ASSERT(sizeof(PyTime_t) == sizeof(frequency));
PyTime_t denom = (PyTime_t)frequency;
// Known QueryPerformanceFrequency() values:
//
// * 10,000,000 (10 MHz): 100 ns resolution
// * 3,579,545 Hz (3.6 MHz): 279 ns resolution
if (_PyTimeFraction_Set(base, SEC_TO_NS, denom) < 0) {
if (raise_exc) {
PyErr_SetString(PyExc_RuntimeError,
"invalid QueryPerformanceFrequency");
}
return -1;
}
return 0;
}
// N.B. If raise_exc=0, this may be called without the GIL.
static int
py_get_win_perf_counter(PyTime_t *tp, _Py_clock_info_t *info, int raise_exc)
{
assert(info == NULL || raise_exc);
if (py_qpc_base.denom == 0) {
if (py_win_perf_counter_frequency(&py_qpc_base, raise_exc) < 0) {
return -1;
}
}
if (info) {
info->implementation = "QueryPerformanceCounter()";
info->resolution = _PyTimeFraction_Resolution(&py_qpc_base);
info->monotonic = 1;
info->adjustable = 0;
}
LARGE_INTEGER now;
QueryPerformanceCounter(&now);
LONGLONG ticksll = now.QuadPart;
/* Make sure that casting LONGLONG to PyTime_t cannot overflow,
both types are signed */
PyTime_t ticks;
static_assert(sizeof(ticksll) <= sizeof(ticks),
"LONGLONG is larger than PyTime_t");
ticks = (PyTime_t)ticksll;
*tp = _PyTimeFraction_Mul(ticks, &py_qpc_base);
return 0;
}
#endif // MS_WINDOWS
#ifdef __APPLE__
static int
py_mach_timebase_info(_PyTimeFraction *base, int raise_exc)
{
mach_timebase_info_data_t timebase;
// 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);
// Check that timebase.numer and timebase.denom can be casted to
// PyTime_t. In practice, timebase uses uint32_t, so casting cannot
// overflow. At the end, only make sure that the type is uint32_t
// (PyTime_t is 64-bit long).
Py_BUILD_ASSERT(sizeof(timebase.numer) <= sizeof(PyTime_t));
Py_BUILD_ASSERT(sizeof(timebase.denom) <= sizeof(PyTime_t));
PyTime_t numer = (PyTime_t)timebase.numer;
PyTime_t denom = (PyTime_t)timebase.denom;
// Known time bases:
//
// * (1, 1) on Intel: 1 ns
// * (1000000000, 33333335) on PowerPC: ~30 ns
// * (1000000000, 25000000) on PowerPC: 40 ns
if (_PyTimeFraction_Set(base, numer, denom) < 0) {
if (raise_exc) {
PyErr_SetString(PyExc_RuntimeError,
"invalid mach_timebase_info");
}
return -1;
}
return 0;
}
#endif
// N.B. If raise_exc=0, this may be called without the GIL.
static int
py_get_monotonic_clock(PyTime_t *tp, _Py_clock_info_t *info, int raise_exc)
{
assert(info == NULL || raise_exc);
if (raise_exc) {
// raise_exc requires to hold the GIL
assert(PyGILState_Check());
}
#if defined(MS_WINDOWS)
if (py_get_win_perf_counter(tp, info, raise_exc) < 0) {
return -1;
}
#elif defined(__APPLE__)
static _PyTimeFraction base = {0, 0};
if (base.denom == 0) {
if (py_mach_timebase_info(&base, raise_exc) < 0) {
return -1;
}
}
if (info) {
info->implementation = "mach_absolute_time()";
info->resolution = _PyTimeFraction_Resolution(&base);
info->monotonic = 1;
info->adjustable = 0;
}
uint64_t uticks = mach_absolute_time();
// unsigned => signed
assert(uticks <= (uint64_t)PyTime_MAX);
PyTime_t ticks = (PyTime_t)uticks;
PyTime_t ns = _PyTimeFraction_Mul(ticks, &base);
*tp = ns;
#elif defined(__hpux)
hrtime_t time = gethrtime();
if (time == -1) {
if (raise_exc) {
PyErr_SetFromErrno(PyExc_OSError);
}
return -1;
}
*tp = time;
if (info) {
info->implementation = "gethrtime()";
info->resolution = 1e-9;
info->monotonic = 1;
info->adjustable = 0;
}
#else
#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
struct timespec ts;
if (clock_gettime(clk_id, &ts) != 0) {
if (raise_exc) {
PyErr_SetFromErrno(PyExc_OSError);
return -1;
}
return -1;
}
if (pytime_fromtimespec(tp, &ts, raise_exc) < 0) {
return -1;
}
if (info) {
info->monotonic = 1;
info->implementation = implementation;
info->adjustable = 0;
struct timespec res;
if (clock_getres(clk_id, &res) != 0) {
PyErr_SetFromErrno(PyExc_OSError);
return -1;
}
info->resolution = res.tv_sec + res.tv_nsec * 1e-9;
}
#endif
return 0;
}
int
PyTime_Monotonic(PyTime_t *result)
{
if (py_get_monotonic_clock(result, NULL, 1) < 0) {
*result = 0;
return -1;
}
return 0;
}
int
PyTime_MonotonicRaw(PyTime_t *result)
{
if (py_get_monotonic_clock(result, NULL, 0) < 0) {
*result = 0;
return -1;
}
return 0;
}
int
_PyTime_MonotonicWithInfo(PyTime_t *tp, _Py_clock_info_t *info)
{
return py_get_monotonic_clock(tp, info, 1);
}
int
_PyTime_PerfCounterWithInfo(PyTime_t *t, _Py_clock_info_t *info)
{
return _PyTime_MonotonicWithInfo(t, info);
}
int
PyTime_PerfCounter(PyTime_t *result)
{
return PyTime_Monotonic(result);
}
int
PyTime_PerfCounterRaw(PyTime_t *result)
{
return PyTime_MonotonicRaw(result);
}
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 defined(_AIX) && (SIZEOF_TIME_T < 8)
/* bpo-34373: AIX does not return NULL if t is too small or too large */
if (t < -2145916800 /* 1902-01-01 */
|| t > 2145916800 /* 2038-01-01 */) {
errno = EINVAL;
PyErr_SetString(PyExc_OverflowError,
"localtime argument out of range");
return -1;
}
#endif
errno = 0;
if (localtime_r(&t, tm) == NULL) {
if (errno == 0) {
errno = EINVAL;
}
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 */
}
PyTime_t
_PyDeadline_Init(PyTime_t timeout)
{
PyTime_t now;
// silently ignore error: cannot report error to the caller
(void)PyTime_MonotonicRaw(&now);
return _PyTime_Add(now, timeout);
}
PyTime_t
_PyDeadline_Get(PyTime_t deadline)
{
PyTime_t now;
// silently ignore error: cannot report error to the caller
(void)PyTime_MonotonicRaw(&now);
return deadline - now;
}
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