1 files changed, 240 insertions, 64 deletions

diff --git a/Python/pytime.c b/Python/pytime.c
index de6a41fe00..a8460c6867 100644
--- a/Python/pytime.c
+++ b/Python/pytime.c
@@ -3,29 +3,24 @@
 #include <windows.h>
 #endif
 
-#if defined(__APPLE__) && defined(HAVE_GETTIMEOFDAY) && defined(HAVE_FTIME)
-  /*
-   * _PyTime_gettimeofday falls back to ftime when getttimeofday fails because the latter
-   * might fail on some platforms. This fallback is unwanted on MacOSX because
-   * that makes it impossible to use a binary build on OSX 10.4 on earlier
-   * releases of the OS. Therefore claim we don't support ftime.
-   */
-# undef HAVE_FTIME
+#if defined(__APPLE__)
+#include <mach/mach_time.h>   /* mach_absolute_time(), mach_timebase_info() */
 #endif
 
-#if defined(HAVE_FTIME) && !defined(MS_WINDOWS)
-#include <sys/timeb.h>
-extern int ftime(struct timeb *);
+#ifdef MS_WINDOWS
+static OSVERSIONINFOEX winver;
 #endif
 
-static void
-pygettimeofday(_PyTime_timeval *tp, _Py_clock_info_t *info)
+static int
+pygettimeofday(_PyTime_timeval *tp, _Py_clock_info_t *info, int raise)
 {
 #ifdef MS_WINDOWS
     FILETIME system_time;
     ULARGE_INTEGER large;
     ULONGLONG microseconds;
 
+    assert(info == NULL || raise);
+
     GetSystemTimeAsFileTime(&system_time);
     large.u.LowPart = system_time.dwLowDateTime;
     large.u.HighPart = system_time.dwHighDateTime;
@@ -37,80 +32,244 @@ pygettimeofday(_PyTime_timeval *tp, _Py_clock_info_t *info)
     tp->tv_usec = microseconds % 1000000;
     if (info) {
         DWORD timeAdjustment, timeIncrement;
-        BOOL isTimeAdjustmentDisabled;
+        BOOL isTimeAdjustmentDisabled, ok;
 
         info->implementation = "GetSystemTimeAsFileTime()";
         info->monotonic = 0;
-        (void) GetSystemTimeAdjustment(&timeAdjustment, &timeIncrement,
-                                       &isTimeAdjustmentDisabled);
+        ok = GetSystemTimeAdjustment(&timeAdjustment, &timeIncrement,
+                                     &isTimeAdjustmentDisabled);
+        if (!ok) {
+            PyErr_SetFromWindowsErr(0);
+            return -1;
+        }
         info->resolution = timeIncrement * 1e-7;
         info->adjustable = 1;
     }
-#else
-    /* There are three ways to get the time:
-      (1) gettimeofday() -- resolution in microseconds
-      (2) ftime() -- resolution in milliseconds
-      (3) time() -- resolution in seconds
-      In all cases the return value in a timeval struct.
-      Since on some systems (e.g. SCO ODT 3.0) gettimeofday() may
-      fail, so we fall back on ftime() or time().
-      Note: clock resolution does not imply clock accuracy! */
-
-#ifdef HAVE_GETTIMEOFDAY
+
+#else   /* MS_WINDOWS */
     int err;
+#ifdef HAVE_CLOCK_GETTIME
+    struct timespec ts;
+#endif
+
+    assert(info == NULL || raise);
+
+#ifdef HAVE_CLOCK_GETTIME
+    err = clock_gettime(CLOCK_REALTIME, &ts);
+    if (err) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    tp->tv_sec = ts.tv_sec;
+    tp->tv_usec = ts.tv_nsec / 1000;
+
+    if (info) {
+        struct timespec res;
+        info->implementation = "clock_gettime(CLOCK_REALTIME)";
+        info->monotonic = 0;
+        info->adjustable = 1;
+        if (clock_getres(CLOCK_REALTIME, &res) == 0)
+            info->resolution = res.tv_sec + res.tv_nsec * 1e-9;
+        else
+            info->resolution = 1e-9;
+    }
+#else   /* HAVE_CLOCK_GETTIME */
+
+     /* test gettimeofday() */
 #ifdef GETTIMEOFDAY_NO_TZ
     err = gettimeofday(tp);
 #else
     err = gettimeofday(tp, (struct timezone *)NULL);
 #endif
-    if (err == 0) {
-        if (info) {
-            info->implementation = "gettimeofday()";
-            info->resolution = 1e-6;
-            info->monotonic = 0;
-            info->adjustable = 1;
-        }
-        return;
-    }
-#endif   /* HAVE_GETTIMEOFDAY */
-
-#if defined(HAVE_FTIME)
-    {
-        struct timeb t;
-        ftime(&t);
-        tp->tv_sec = t.time;
-        tp->tv_usec = t.millitm * 1000;
-        if (info) {
-            info->implementation = "ftime()";
-            info->resolution = 1e-3;
-            info->monotonic = 0;
-            info->adjustable = 1;
-        }
+    if (err) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
     }
-#else /* !HAVE_FTIME */
-    tp->tv_sec = time(NULL);
-    tp->tv_usec = 0;
+
     if (info) {
-        info->implementation = "time()";
-        info->resolution = 1.0;
+        info->implementation = "gettimeofday()";
+        info->resolution = 1e-6;
         info->monotonic = 0;
         info->adjustable = 1;
     }
-#endif /* !HAVE_FTIME */
-
-#endif /* MS_WINDOWS */
+#endif   /* !HAVE_CLOCK_GETTIME */
+#endif   /* !MS_WINDOWS */
+    assert(0 <= tp->tv_usec && tp->tv_usec < 1000 * 1000);
+    return 0;
 }
 
 void
 _PyTime_gettimeofday(_PyTime_timeval *tp)
 {
-    pygettimeofday(tp, NULL);
+    if (pygettimeofday(tp, NULL, 0) < 0) {
+        /* cannot happen, _PyTime_Init() checks that pygettimeofday() works */
+        assert(0);
+        tp->tv_sec = 0;
+        tp->tv_usec = 0;
+    }
 }
 
-void
+int
 _PyTime_gettimeofday_info(_PyTime_timeval *tp, _Py_clock_info_t *info)
 {
-    pygettimeofday(tp, 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 = {0, -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(last.tv_usec == -1
+           || 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
@@ -245,8 +404,25 @@ _PyTime_ObjectToTimeval(PyObject *obj, time_t *sec, long *usec,
     return _PyTime_ObjectToDenominator(obj, sec, usec, 1e6, round);
 }
 
-void
-_PyTime_Init()
+int
+_PyTime_Init(void)
 {
-    /* Do nothing.  Needed to force linking. */
+    _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;
 }