Use a fraction internally in the _PyTime API to reduce the risk of
integer overflow: simplify the fraction using Greatest Common
Divisor (GCD). The fraction API is used by time functions:
perf_counter(), monotonic() and process_time().
For example, QueryPerformanceFrequency() usually returns 10 MHz on
Windows 10 and newer. The fraction SEC_TO_NS / frequency =
1_000_000_000 / 10_000_000 can be simplified to 100 / 1.
* Add _PyTimeFraction type.
* Add functions:
* _PyTimeFraction_Set()
* _PyTimeFraction_Mul()
* _PyTimeFraction_Resolution()
* No longer check "numer * denom <= _PyTime_MAX" in
_PyTimeFraction_Set(). _PyTimeFraction_Mul() uses _PyTime_Mul()
which handles integer overflow.
Add wrapper for timerfd_create, timerfd_settime, and timerfd_gettime to os module.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
Python.h no longer includes <time.h>, <sys/select.h> and <sys/time.h>
standard header files.
* Add <time.h> include to xxsubtype.c.
* Add <sys/time.h> include to posixmodule.c and semaphore.c.
* readline.c includes <sys/select.h> instead of <sys/time.h>.
* resource.c no longer includes <time.h> and <sys/time.h>.
Remove the "cpython/pytime.h" header file: it only contained private
functions. Move functions to the internal pycore_time.h header file.
Move tests from _testcapi to _testinternalcapi. Rename also test
methods to have the same name than tested C functions.
No longer export these functions:
* _PyTime_Add()
* _PyTime_As100Nanoseconds()
* _PyTime_FromMicrosecondsClamp()
* _PyTime_FromTimespec()
* _PyTime_FromTimeval()
* _PyTime_GetPerfCounterWithInfo()
* _PyTime_MulDiv()
Python 3.11 now uses C11 standard which adds static_assert()
to <assert.h>.
* In pytime.c, replace Py_BUILD_ASSERT() with preprocessor checks on
SIZEOF_TIME_T with #error.
* On macOS, py_mach_timebase_info() now accepts timebase members with
the same size than _PyTime_t.
* py_get_monotonic_clock() now saturates GetTickCount64() to
_PyTime_MAX: GetTickCount64() is unsigned, whereas _PyTime_t is
signed.
Remove the following math macros using the errno variable:
* Py_ADJUST_ERANGE1()
* Py_ADJUST_ERANGE2()
* Py_OVERFLOWED()
* Py_SET_ERANGE_IF_OVERFLOW()
* Py_SET_ERRNO_ON_MATH_ERROR()
Create pycore_pymath.h internal header file.
Rename Py_ADJUST_ERANGE1() and Py_ADJUST_ERANGE2() to
_Py_ADJUST_ERANGE1() and _Py_ADJUST_ERANGE2(), and convert these
macros to static inline functions.
Move the following macros to pycore_pymath.h:
* _Py_IntegralTypeSigned()
* _Py_IntegralTypeMax()
* _Py_IntegralTypeMin()
* _Py_InIntegralTypeRange()
Add a private C API for deadlines: add _PyDeadline_Init() and
_PyDeadline_Get() functions.
* Add _PyTime_Add() and _PyTime_Mul() functions which compute t1+t2
and t1*t2 and clamp the result on overflow.
* _PyTime_MulDiv() now uses _PyTime_Add() and _PyTime_Mul().
Add pytime_add() and pytime_mul() functions to pytime.c to compute
t+t2 and t*k with clamping to [_PyTime_MIN; _PyTime_MAX].
Fix pytime.h: _PyTime_FromTimeval() is not implemented on Windows.
Add the _PyTime_AsTimespec_clamp() function: similar to
_PyTime_AsTimespec(), but clamp to _PyTime_t min/max and don't raise
an exception.
PyThread_acquire_lock_timed() now uses _PyTime_AsTimespec_clamp() to
remove the Py_UNREACHABLE() code path.
* Add _PyTime_AsTime_t() function.
* Add PY_TIME_T_MIN and PY_TIME_T_MAX constants.
* Replace _PyTime_AsTimeval_noraise() with _PyTime_AsTimeval_clamp().
* Add pytime_divide_round_up() function.
* Fix integer overflow in pytime_divide().
* Add pytime_divmod() function.
py_win_perf_counter_frequency() no longer checks for
QueryPerformanceFrequency() failure. According to the
QueryPerformanceFrequency() documentation, the function can no longer
fails since Windows XP.
On Windows, time.sleep() now uses a waitable timer which has a
resolution of 100 ns (10^-7 sec). Previously, it had a solution of 1
ms (10^-3 sec).
* On Windows, time.sleep() now calls PyErr_CheckSignals() before
resetting the SIGINT event.
* Add _PyTime_As100Nanoseconds() function.
* Complete and update time.sleep() documentation.
Co-authored-by: Livius <egyszeregy@freemail.hu>
Refactor pytime.c:
* Add pytime_from_nanoseconds() and pytime_as_nanoseconds(),
and use explicitly these functions
* Add two empty lines between functions
* PEP 7: add braces { ... }
* C99: declare variables where they are set
* Rename private functions to lowercase
* Rename error_time_t_overflow() to pytime_time_t_overflow()
* Rename win_perf_counter_frequency() to py_win_perf_counter_frequency()
* py_get_monotonic_clock(): add an assertion to detect overflow when
mach_absolute_time() unsigned uint64_t is casted to _PyTime_t
(signed int64_t).
_testcapi: use _PyTime_FromNanoseconds().
time.time(), time.perf_counter() and time.monotonic() functions can
no longer fail with a Python fatal error, instead raise a regular
Python exception on failure.
Remove _PyTime_Init(): don't check system, monotonic and perf counter
clocks at startup anymore.
On error, _PyTime_GetSystemClock(), _PyTime_GetMonotonicClock() and
_PyTime_GetPerfCounter() now silently ignore the error and return 0.
They cannot fail with a Python fatal error anymore.
Add py_mach_timebase_info() and win_perf_counter_frequency()
sub-functions.
time.perf_counter() on Windows and time.monotonic() on macOS are now
system-wide. Previously, they used an offset computed at startup to
reduce the precision loss caused by the float type. Use
time.perf_counter_ns() and time.monotonic_ns() added in Python 3.7 to
avoid this precision loss.
Co-authored-by: Lawrence D’Anna <lawrence_danna@apple.com>
* Add support for macOS 11 and Apple Silicon (aka arm64)
As a side effect of this work use the system copy of libffi on macOS, and remove the vendored copy
* Support building on recent versions of macOS while deploying to older versions
This allows building installers on macOS 11 while still supporting macOS 10.9.
Fix time.mktime() error handling on AIX for year before 1970.
Other changes:
* mktime(): rename variable 'buf' to 'tm'.
* _PyTime_localtime():
* Use "localtime" rather than "ctime" in the error message
(specific to AIX).
* Always initialize errno to 0 just in case if localtime_r()
doesn't set errno on error.
* On AIX, avoid abs() which is limited to int type.
* EINVAL constant is now always available.
* Fix test_mktime on AIX by adding code to get mktime to behave the
same way as it does on other *nix systems
* Fix test_pthread_getcpuclickid in AIX by adjusting the test case
expectations when running on AIX in 32-bit mode
Patch by Michael Felt.
Add new time functions:
* time.clock_gettime_ns()
* time.clock_settime_ns()
* time.monotonic_ns()
* time.perf_counter_ns()
* time.process_time_ns()
* time.time_ns()
Add new _PyTime functions:
* _PyTime_FromTimespec()
* _PyTime_FromNanosecondsObject()
* _PyTime_FromTimeval()
Other changes:
* Add also os.times() tests to test_os.
* pytime_fromtimeval() and pytime_fromtimeval() now return
_PyTime_MAX or _PyTime_MIN on overflow, rather than undefined
behaviour
* _PyTime_FromNanoseconds() parameter type changes from long long to
_PyTime_t
* Rewrite win_perf_counter() to only use integers internally.
* Add _PyTime_MulDiv() which compute "ticks * mul / div"
in two parts (int part and remaining) to prevent integer overflow.
* Clock frequency is checked at initialization for integer overflow.
* Enhance also pymonotonic() to reduce the precision loss on macOS
(mach_absolute_time() clock).
time.clock() and time.perf_counter() now use again C double
internally.
Remove also _PyTime_GetWinPerfCounterWithInfo(): use
_PyTime_GetPerfCounterDoubleWithInfo() instead on Windows.
* Add Py_UNREACHABLE() as an alias to abort().
* Use Py_UNREACHABLE() instead of assert(0)
* Convert more unreachable code to use Py_UNREACHABLE()
* Document Py_UNREACHABLE() and a few other macros.
* bpo-30183: Fixes HP-UX cc compilation error in pytime.c
HP-UX does not support the CLOCK_MONOTONIC identifier, and will fail to
compile:
"Python/pytime.c", line 723: error #2020: identifier
"CLOCK_MONOTONIC" is undefined
const clockid_t clk_id = CLOCK_MONOTONIC;
Add a new section for __hpux that calls 'gethrtime()' instead of
'clock_gettime()'.
* bpo-30183: Removes unnecessary return
On the x86 OpenBSD 5.8 buildbot, the integer overflow check is ignored. Copy
the tv_sec variable into a Py_time_t variable instead of "simply" casting it to
Py_time_t, to fix the integer overflow check.
Victor Stinner
Petr Viktorin
Masaru Tsuchiyama
Inada Naoki
Mark Dickinson
Ronald Oussoren
Minmin Gong
Serhiy Storchaka
Michael Felt
Benjamin Peterson
Victor Stinner
luzpaz
Victor Stinner
Pablo Galindo
Barry Warsaw
Han Lee
Antoine Pitrou
haney
Alexander Belopolsky