Issue #13846: Add time.monotonic(), monotonic clock.

This commit is contained in:
Victor Stinner 2012-02-07 23:29:46 +01:00
parent d1cd99b533
commit 8b30201f7d
4 changed files with 94 additions and 16 deletions

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@ -226,6 +226,14 @@ The module defines the following functions and data items:
The earliest date for which it can generate a time is platform-dependent.
.. function:: monotonic()
Monotonic clock. The reference point of the returned value is undefined so
only the difference of consecutive calls is valid.
.. versionadded: 3.3
.. function:: sleep(secs)
Suspend execution for the given number of seconds. The argument may be a

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@ -331,16 +331,32 @@ class TimeTestCase(unittest.TestCase):
pass
self.assertEqual(time.strftime('%Z', tt), tzname)
@unittest.skipUnless(hasattr(time, 'monotonic'),
'need time.monotonic()')
def test_monotonic(self):
t1 = time.monotonic()
t2 = time.monotonic()
self.assertGreaterEqual(t2, t1)
t1 = time.monotonic()
time.sleep(0.1)
t2 = time.monotonic()
dt = t2 - t1
self.assertGreater(t2, t1)
self.assertAlmostEqual(dt, 0.1, delta=0.2)
def test_wallclock(self):
t1 = time.wallclock()
t2 = time.wallclock()
# may fail if the system clock was changed
self.assertGreaterEqual(t2, t1)
t1 = time.wallclock()
time.sleep(0.1)
t2 = time.wallclock()
self.assertGreater(t2, t1)
dt = t2 - t1
# may fail if the system clock was changed
self.assertGreater(t2, t1)
self.assertAlmostEqual(dt, 0.1, delta=0.2)
def test_localtime_failure(self):

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@ -466,6 +466,8 @@ Core and Builtins
Library
-------
- Issue #13846: Add time.monotonic(), monotonic clock.
- Issue #10811: Fix recursive usage of cursors. Instead of crashing,
raise a ProgrammingError now.

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@ -91,39 +91,44 @@ pyclock(void)
/* Win32 has better clock replacement; we have our own version, due to Mark
Hammond and Tim Peters */
static PyObject *
time_clock(PyObject *self, PyObject *unused)
win32_clock(int fallback)
{
static LARGE_INTEGER ctrStart;
static double divisor = 0.0;
static LONGLONG cpu_frequency = 0;
static LONGLONG ctrStart;
LARGE_INTEGER now;
double diff;
if (divisor == 0.0) {
if (cpu_frequency == 0) {
LARGE_INTEGER freq;
QueryPerformanceCounter(&ctrStart);
QueryPerformanceCounter(&now);
ctrStart = now.QuadPart;
if (!QueryPerformanceFrequency(&freq) || freq.QuadPart == 0) {
/* Unlikely to happen - this works on all intel
machines at least! Revert to clock() */
return pyclock();
if (fallback)
return pyclock();
else
return PyErr_SetFromWindowsErr(0);
}
divisor = (double)freq.QuadPart;
cpu_frequency = freq.QuadPart;
}
QueryPerformanceCounter(&now);
diff = (double)(now.QuadPart - ctrStart.QuadPart);
return PyFloat_FromDouble(diff / divisor);
diff = (double)(now.QuadPart - ctrStart);
return PyFloat_FromDouble(diff / (double)cpu_frequency);
}
#endif
#elif defined(HAVE_CLOCK)
#if (defined(MS_WINDOWS) && !defined(__BORLANDC__)) || defined(HAVE_CLOCK)
static PyObject *
time_clock(PyObject *self, PyObject *unused)
{
#if defined(MS_WINDOWS) && !defined(__BORLANDC__)
return win32_clock(1);
#else
return pyclock();
#endif
}
#endif /* HAVE_CLOCK */
#ifdef HAVE_CLOCK
PyDoc_STRVAR(clock_doc,
"clock() -> floating point number\n\
\n\
@ -767,7 +772,7 @@ static PyObject *
time_wallclock(PyObject *self, PyObject *unused)
{
#if defined(MS_WINDOWS) && !defined(__BORLANDC__)
return time_clock(self, NULL);
return win32_clock(1);
#elif defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
static int clk_index = 0;
clockid_t clk_ids[] = {
@ -809,6 +814,50 @@ required, i.e. when \"processor time\" is inappropriate. The reference point\n\
of the returned value is undefined so only the difference of consecutive\n\
calls is valid.");
#if (defined(MS_WINDOWS) && !defined(__BORLANDC__)) \
|| (defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC))
# define HAVE_PYTIME_MONOTONIC
#endif
#ifdef HAVE_PYTIME_MONOTONIC
static PyObject *
time_monotonic(PyObject *self, PyObject *unused)
{
#if defined(MS_WINDOWS) && !defined(__BORLANDC__)
return win32_clock(0);
#else
static int clk_index = 0;
clockid_t clk_ids[] = {
#ifdef CLOCK_MONOTONIC_RAW
CLOCK_MONOTONIC_RAW,
#endif
CLOCK_MONOTONIC
};
int ret;
struct timespec tp;
while (0 <= clk_index) {
clockid_t clk_id = clk_ids[clk_index];
ret = clock_gettime(clk_id, &tp);
if (ret == 0)
return PyFloat_FromDouble(tp.tv_sec + tp.tv_nsec * 1e-9);
clk_index++;
if (Py_ARRAY_LENGTH(clk_ids) <= clk_index)
clk_index = -1;
}
PyErr_SetFromErrno(PyExc_OSError);
return NULL;
#endif
}
PyDoc_STRVAR(monotonic_doc,
"monotonic() -> float\n\
\n\
Monotonic clock. The reference point of the returned value is undefined so\n\
only the difference of consecutive calls is valid.");
#endif
static void
PyInit_timezone(PyObject *m) {
/* This code moved from PyInit_time wholesale to allow calling it from
@ -937,6 +986,9 @@ static PyMethodDef time_methods[] = {
#ifdef HAVE_MKTIME
{"mktime", time_mktime, METH_O, mktime_doc},
#endif
#ifdef HAVE_PYTIME_MONOTONIC
{"monotonic", time_monotonic, METH_NOARGS, monotonic_doc},
#endif
#ifdef HAVE_STRFTIME
{"strftime", time_strftime, METH_VARARGS, strftime_doc},
#endif