Modules/timemodule.c

cpython 3.14 @ ab2d84fe1023/Modules/timemodule.c ↗

Modules/timemodule.c implements the time module. It wraps POSIX clock_gettime (or Windows QueryPerformanceCounter) to expose wall-clock, monotonic, and CPU-time clocks.

Map

Lines	Symbol	Role
1-300	_PyTime_t typedef, _PyTime_GetSystemClock	Internal nanosecond clock type
301-600	time_time, time_time_ns, time_monotonic	Wall-clock and monotonic clocks
601-800	time_perf_counter, time_process_time	Performance and CPU clocks
801-1100	time_sleep	Sleep with EINTR retry
1101-1500	time_gmtime, time_localtime, time_mktime	Calendar conversion
1501-1900	time_strftime, struct_time	Formatting and the named-tuple time type

Reading

_PyTime_t nanosecond integer

All internal time values are stored as _PyTime_t (a 64-bit nanosecond count). The time.time_ns() function returns this value directly as a Python int. time.time() divides by 1e9 to get a float, which loses sub-microsecond precision.

time_sleep EINTR retry

time.sleep(secs) translates to nanosleep on POSIX. If nanosleep is interrupted by a signal (EINTR), the C code checks the remaining time and retries without exposing the interruption to Python. A KeyboardInterrupt is handled by the normal pending-signals check after the sleep returns.

// CPython: Modules/timemodule.c:890 time_sleep
static int
pysleep(_PyTime_t timeout)
{
    do {
        err = _PyTime_AsTimeval(timeout, &timeout_abs, _PyTime_ROUND_CEILING);
        ...
        ret = select(0, NULL, NULL, NULL, &timeout_val);
        ...
    } while (ret != 0 && errno == EINTR && !Py_MakePendingCalls());
    return 0;
}

struct_time

struct_time is a named-tuple subclass with 11 fields: tm_year, tm_mon, tm_mday, tm_hour, tm_min, tm_sec, tm_wday, tm_yday, tm_isdst, and (since 3.3) tm_gmtoff, tm_zone.

gopy notes

module/sys/module.go partially overlaps with time. A dedicated module/time/ port is planned. The Go equivalent of _PyTime_t is time.Time (nanosecond resolution). time.sleep maps to time.Sleep. struct_time is a named-tuple that requires named-tuple support in the gopy objects layer.