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      1 /*
      2  * ptw32_relmillisecs.c
      3  *
      4  * Description:
      5  * This translation unit implements miscellaneous thread functions.
      6  *
      7  * --------------------------------------------------------------------------
      8  *
      9  *      Pthreads-win32 - POSIX Threads Library for Win32
     10  *      Copyright(C) 1998 John E. Bossom
     11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
     12  *
     13  *      Contact Email: rpj (at) callisto.canberra.edu.au
     14  *
     15  *      The current list of contributors is contained
     16  *      in the file CONTRIBUTORS included with the source
     17  *      code distribution. The list can also be seen at the
     18  *      following World Wide Web location:
     19  *      http://sources.redhat.com/pthreads-win32/contributors.html
     20  *
     21  *      This library is free software; you can redistribute it and/or
     22  *      modify it under the terms of the GNU Lesser General Public
     23  *      License as published by the Free Software Foundation; either
     24  *      version 2 of the License, or (at your option) any later version.
     25  *
     26  *      This library is distributed in the hope that it will be useful,
     27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
     28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     29  *      Lesser General Public License for more details.
     30  *
     31  *      You should have received a copy of the GNU Lesser General Public
     32  *      License along with this library in the file COPYING.LIB;
     33  *      if not, write to the Free Software Foundation, Inc.,
     34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
     35  */
     36 
     37 #include "pthread.h"
     38 #include "implement.h"
     39 #if !defined(NEED_FTIME)
     40 #include <sys/timeb.h>
     41 #endif
     42 
     43 
     44 #if defined(PTW32_BUILD_INLINED)
     45 INLINE
     46 #endif /* PTW32_BUILD_INLINED */
     47 DWORD
     48 ptw32_relmillisecs (const struct timespec * abstime)
     49 {
     50   const int64_t NANOSEC_PER_MILLISEC = 1000000;
     51   const int64_t MILLISEC_PER_SEC = 1000;
     52   DWORD milliseconds;
     53   int64_t tmpAbsMilliseconds;
     54   int64_t tmpCurrMilliseconds;
     55 #if defined(NEED_FTIME)
     56   struct timespec currSysTime;
     57   FILETIME ft;
     58   SYSTEMTIME st;
     59 #else /* ! NEED_FTIME */
     60 #if ( defined(_MSC_VER) && _MSC_VER >= 1300 ) || \
     61     ( (defined(__MINGW64__) || defined(__MINGW32__)) && __MSVCRT_VERSION__ >= 0x0601 )
     62   struct __timeb64 currSysTime;
     63 #else
     64   struct _timeb currSysTime;
     65 #endif
     66 #endif /* NEED_FTIME */
     67 
     68 
     69   /*
     70    * Calculate timeout as milliseconds from current system time.
     71    */
     72 
     73   /*
     74    * subtract current system time from abstime in a way that checks
     75    * that abstime is never in the past, or is never equivalent to the
     76    * defined INFINITE value (0xFFFFFFFF).
     77    *
     78    * Assume all integers are unsigned, i.e. cannot test if less than 0.
     79    */
     80   tmpAbsMilliseconds =  (int64_t)abstime->tv_sec * MILLISEC_PER_SEC;
     81   tmpAbsMilliseconds += ((int64_t)abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC;
     82 
     83   /* get current system time */
     84 
     85 #if defined(NEED_FTIME)
     86 
     87   GetSystemTime(&st);
     88   SystemTimeToFileTime(&st, &ft);
     89   /*
     90    * GetSystemTimeAsFileTime(&ft); would be faster,
     91    * but it does not exist on WinCE
     92    */
     93 
     94   ptw32_filetime_to_timespec(&ft, &currSysTime);
     95 
     96   tmpCurrMilliseconds = (int64_t)currSysTime.tv_sec * MILLISEC_PER_SEC;
     97   tmpCurrMilliseconds += ((int64_t)currSysTime.tv_nsec + (NANOSEC_PER_MILLISEC/2))
     98 			   / NANOSEC_PER_MILLISEC;
     99 
    100 #else /* ! NEED_FTIME */
    101 
    102 #if defined(_MSC_VER) && _MSC_VER >= 1400
    103   _ftime64_s(&currSysTime);
    104 #elif ( defined(_MSC_VER) && _MSC_VER >= 1300 ) || \
    105       ( (defined(__MINGW64__) || defined(__MINGW32__)) && __MSVCRT_VERSION__ >= 0x0601 )
    106   _ftime64(&currSysTime);
    107 #else
    108   _ftime(&currSysTime);
    109 #endif
    110 
    111   tmpCurrMilliseconds = (int64_t) currSysTime.time * MILLISEC_PER_SEC;
    112   tmpCurrMilliseconds += (int64_t) currSysTime.millitm;
    113 
    114 #endif /* NEED_FTIME */
    115 
    116   if (tmpAbsMilliseconds > tmpCurrMilliseconds)
    117     {
    118       milliseconds = (DWORD) (tmpAbsMilliseconds - tmpCurrMilliseconds);
    119       if (milliseconds == INFINITE)
    120         {
    121           /* Timeouts must be finite */
    122           milliseconds--;
    123         }
    124     }
    125   else
    126     {
    127       /* The abstime given is in the past */
    128       milliseconds = 0;
    129     }
    130 
    131   return milliseconds;
    132 }
    133