gh-112567: Add _PyTimeFraction C API #112568
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Use a fraction internally in the _PyTime API to reduce the risk of integer overflow: simplify the fraction using Greatest Common Denominator (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.
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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.
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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.
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Use a fraction internally in the _PyTime API to reduce the risk of integer overflow: simplify the fraction using Greatest Common Denominator (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:
Remove _PyTime_Init().
Remove _PyRuntimeState.time member.
os.times() now calls _Py_GetTicksPerSecond().
Rename _PyTime_GetClockWithInfo() to py_clock().