src/timing/cl_t_current.cc

   1 // cl_current_time().
   2
   3 #if defined(_WIN32) && !defined(__CYGWIN__)
   4 #include <windows.h> // For GetSystemTimeAsFileTime(), must be included first, sorry.
   5 #endif
   6
   7 // General includes.
   8 #include "base/cl_sysdep.h"
   9
  10 // Specification.
  11 #include "cln/timing.h"
  12
  13
  14 // Implementation.
  15
  16 #include "timing/cl_t_config.h"
  17
  18
  19 #if defined(HAVE_GETTIMEOFDAY)
  20   #include <sys/time.h>
  21   #ifdef GETTIMEOFDAY_DOTS
  22     extern "C" int gettimeofday (struct timeval * tp, ...);
  23   #else
  24     extern "C" int gettimeofday (struct timeval * tp, GETTIMEOFDAY_TZP_T tzp);
  25   #endif
  26 #elif defined(_WIN32) && !defined(__CYGWIN__)
  27   /* <windows.h> included above. */
  28 #else
  29   #include <ctime>
  30 #endif
  31 #ifdef HAVE_PERROR_DECL
  32   #include <cerrno>
  33   #include <cstdio>
  34 #else
  35   extern "C" int perror (const char *);
  36 #endif
  37
  38 namespace cln {
  39
  40 const cl_timespec cl_current_time ()
  41 {
  42 #if defined(HAVE_GETTIMEOFDAY)
  43         var struct timeval tv;
  44         if (gettimeofday(&tv,NULL) != 0) {
  45                 perror("gettimeofday");
  46                 tv.tv_sec = 0; tv.tv_usec = 0;
  47         }
  48         return cl_timespec(tv.tv_sec,
  49                            tv.tv_usec * (1000000000/1000000)
  50                           );
  51 #elif defined(_WIN32) && !defined(__CYGWIN__)
  52
  53         /* GetSystemTimePreciseAsFileTime was introduced only in Windows 8.  */
  54         typedef void (WINAPI * GetSystemTimePreciseAsFileTimeFuncType) (FILETIME *lpTime);
  55         static GetSystemTimePreciseAsFileTimeFuncType GetSystemTimePreciseAsFileTimeFunc = NULL;
  56         static BOOL initialized = FALSE;
  57
  58         if (!initialized) {
  59                 HMODULE kernel32 = LoadLibrary ("kernel32.dll");
  60                 if (kernel32 != NULL) {
  61                         GetSystemTimePreciseAsFileTimeFunc =
  62                                 (GetSystemTimePreciseAsFileTimeFuncType) (void *) GetProcAddress (kernel32, "GetSystemTimePreciseAsFileTime");
  63                 }
  64                 initialized = TRUE;
  65         }
  66
  67         FILETIME current_time;
  68
  69         if (GetSystemTimePreciseAsFileTimeFunc != NULL)
  70                 GetSystemTimePreciseAsFileTimeFunc (&current_time);
  71         else
  72                 GetSystemTimeAsFileTime (&current_time);
  73
  74         /* Convert from FILETIME to 'struct timeval'.  */
  75         /* FILETIME: <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-filetime> */
  76         ULONGLONG since_1601 =
  77                 ((ULONGLONG) current_time.dwHighDateTime << 32)
  78                 | (ULONGLONG) current_time.dwLowDateTime;
  79         /* Between 1601-01-01 and 1970-01-01 there were 280 normal years and 89 leap
  80            years, in total 134774 days.  */
  81         ULONGLONG since_1970 =
  82                 since_1601 - (ULONGLONG) 134774 * (ULONGLONG) 86400 * (ULONGLONG) 10000000;
  83         ULONGLONG microseconds_since_1970 = since_1970 / (ULONGLONG) 10;
  84         return cl_timespec(microseconds_since_1970 / (ULONGLONG) 1000000,
  85                            (microseconds_since_1970 % (ULONGLONG) 1000000) * (1000000000/1000000)
  86                           );
  87
  88 #else
  89         return cl_timespec(time(NULL),0);
  90 #endif
  91 }
  92
  93 }  // namespace cln