diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/pytime.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/Python/pytime.c b/Python/pytime.c index 395a432..9964195 100644 --- a/Python/pytime.c +++ b/Python/pytime.c @@ -3,6 +3,14 @@ #include <windows.h> #endif +#if defined(__APPLE__) +#include <mach/mach_time.h> /* mach_absolute_time(), mach_timebase_info() */ +#endif + +#ifdef MS_WINDOWS +static OSVERSIONINFOEX winver; +#endif + static int pygettimeofday(_PyTime_timeval *tp, _Py_clock_info_t *info, int raise) { @@ -109,6 +117,160 @@ _PyTime_gettimeofday_info(_PyTime_timeval *tp, _Py_clock_info_t *info) return pygettimeofday(tp, info, 1); } +static int +pymonotonic(_PyTime_timeval *tp, _Py_clock_info_t *info, int raise) +{ +#ifdef Py_DEBUG + static _PyTime_timeval last = {-1, -1}; +#endif +#if defined(MS_WINDOWS) + static ULONGLONG (*GetTickCount64) (void) = NULL; + static ULONGLONG (CALLBACK *Py_GetTickCount64)(void); + static int has_gettickcount64 = -1; + ULONGLONG result; + + assert(info == NULL || raise); + + if (has_gettickcount64 == -1) { + /* GetTickCount64() was added to Windows Vista */ + has_gettickcount64 = (winver.dwMajorVersion >= 6); + if (has_gettickcount64) { + HINSTANCE hKernel32; + hKernel32 = GetModuleHandleW(L"KERNEL32"); + *(FARPROC*)&Py_GetTickCount64 = GetProcAddress(hKernel32, + "GetTickCount64"); + assert(Py_GetTickCount64 != NULL); + } + } + + if (has_gettickcount64) { + result = Py_GetTickCount64(); + } + else { + static DWORD last_ticks = 0; + static DWORD n_overflow = 0; + DWORD ticks; + + ticks = GetTickCount(); + if (ticks < last_ticks) + n_overflow++; + last_ticks = ticks; + + result = (ULONGLONG)n_overflow << 32; + result += ticks; + } + + tp->tv_sec = result / 1000; + tp->tv_usec = (result % 1000) * 1000; + + if (info) { + DWORD timeAdjustment, timeIncrement; + BOOL isTimeAdjustmentDisabled, ok; + if (has_gettickcount64) + info->implementation = "GetTickCount64()"; + else + info->implementation = "GetTickCount()"; + 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(); + + /* nanoseconds => microseconds */ + time /= 1000; + /* apply timebase factor */ + time *= timebase.numer; + time /= timebase.denom; + tp->tv_sec = time / (1000 * 1000); + tp->tv_usec = time % (1000 * 1000); + + 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; + } + tp->tv_sec = 0; + tp->tv_usec = 0; + 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; + } + tp->tv_sec = ts.tv_sec; + tp->tv_usec = ts.tv_nsec / 1000; +#endif + assert(0 <= tp->tv_usec && tp->tv_usec < 1000 * 1000); +#ifdef Py_DEBUG + /* monotonic clock cannot go backward */ + assert(tp->tv_sec > last.tv_sec + || (tp->tv_sec == last.tv_sec && tp->tv_usec >= last.tv_usec)); + last = *tp; +#endif + return 0; +} + +void +_PyTime_monotonic(_PyTime_timeval *tp) +{ + if (pymonotonic(tp, NULL, 0) < 0) { + /* cannot happen, _PyTime_Init() checks that pymonotonic() works */ + assert(0); + tp->tv_sec = 0; + tp->tv_usec = 0; + } +} + +int +_PyTime_monotonic_info(_PyTime_timeval *tp, _Py_clock_info_t *info) +{ + return pymonotonic(tp, info, 1); +} + static void error_time_t_overflow(void) { @@ -245,8 +407,21 @@ int _PyTime_Init(void) { _PyTime_timeval tv; + +#ifdef MS_WINDOWS + winver.dwOSVersionInfoSize = sizeof(winver); + if (!GetVersionEx((OSVERSIONINFO*)&winver)) { + PyErr_SetFromWindowsErr(0); + return -1; + } +#endif + /* ensure that the system clock works */ if (_PyTime_gettimeofday_info(&tv, NULL) < 0) return -1; + + /* ensure that the operating system provides a monotonic clock */ + if (_PyTime_monotonic_info(&tv, NULL) < 0) + return -1; return 0; } |