bpo-31773: _PyTime_GetPerfCounter() uses _PyTime_t (GH-3983)

* 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).
This commit is contained in:
Victor Stinner 2017-10-16 08:44:31 -07:00 committed by GitHub
parent 0df19055c9
commit bdaeb7d237
4 changed files with 137 additions and 50 deletions

View file

@ -1669,10 +1669,10 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
else {
static int ximporttime = 0;
static int import_level;
static double accumulated;
static _PyTime_t accumulated;
_Py_IDENTIFIER(importtime);
double t1 = 0, accumulated_copy = accumulated;
_PyTime_t t1 = 0, accumulated_copy = accumulated;
Py_XDECREF(mod);
@ -1695,7 +1695,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
if (ximporttime) {
import_level++;
t1 = _PyTime_GetPerfCounterDouble();
t1 = _PyTime_GetPerfCounter();
accumulated = 0;
}
@ -1711,12 +1711,12 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
mod != NULL);
if (ximporttime) {
double cum = _PyTime_GetPerfCounterDouble() - t1;
_PyTime_t cum = _PyTime_GetPerfCounter() - t1;
import_level--;
fprintf(stderr, "import time: %9ld | %10ld | %*s%s\n",
(long)ceil((cum - accumulated) * 1e6),
(long)ceil(cum * 1e6),
(long)_PyTime_AsMicroseconds(cum - accumulated, _PyTime_ROUND_CEILING),
(long)_PyTime_AsMicroseconds(cum, _PyTime_ROUND_CEILING),
import_level*2, "", PyUnicode_AsUTF8(abs_name));
accumulated = accumulated_copy + cum;