cosmopolitan/third_party/python/Python/pytime.c
Justine Tunney 9b29358511 Make whitespace changes
Status lines for Emacs and Vim have been added to Python sources so
they'll be easier to edit using Python's preferred coding style.

Some DNS helper functions have been broken up into multiple files. It's
nice to have one function per file whenever possible, since that way we
don't need -ffunction-sections.  Another reason it's good to have small
source files, is because the build will be enforcing resource limits on
compilation and testing soon.
2021-08-13 03:20:45 -07:00

866 lines
21 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=4 sts=4 sw=4 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Python 3 │
│ https://docs.python.org/3/license.html │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/weirdtypes.h"
#include "libc/math.h"
#include "libc/sysv/consts/clock.h"
#include "libc/time/time.h"
#include "third_party/python/Include/floatobject.h"
#include "third_party/python/Include/longobject.h"
#include "third_party/python/Include/object.h"
#include "third_party/python/Include/pyerrors.h"
#include "third_party/python/Include/pymacro.h"
#include "third_party/python/Include/pymath.h"
#include "third_party/python/Include/pytime.h"
/* clang-format off */
#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)
typedef int clockid_t;
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 */
}