pd.if.org Git - pdclib/blob - platform/win32/functions/threads/mtx_timedlock.c

   1 #ifndef REGTEST
   2 #include <threads.h>
   3 #include <windows.h>
   4 #include <stdint.h>
   5
   6 int mtx_timedlock(mtx_t *_PDCLIB_restrict mtx,
   7                   const struct timespec *_PDCLIB_restrict until)
   8 {
   9     DWORD myId = GetCurrentThreadId();
  10
  11     if(mtx->_ThreadId == (long) myId) {
  12         mtx->_NestCount++;
  13         return thrd_success;
  14     }
  15
  16
  17     for(;;) {
  18         LONG prev = InterlockedCompareExchange(&mtx->_ThreadId, myId, 0);
  19         if(prev == 0)
  20             return thrd_success;
  21
  22         struct timespec now;
  23         int32_t msToWait = 0;
  24         if(timespec_get(&now, TIME_UTC) != TIME_UTC) {
  25             // timespec_get must work!
  26             return thrd_error;
  27         } else {
  28             int64_t deltaSec  = (int64_t)until->tv_sec  - now.tv_sec;
  29             long    deltaNsec = (long)until->tv_nsec - now.tv_nsec;
  30
  31             if(INT32_MAX / 2000U < deltaSec) {
  32                 // Risk of overflow - do a shorter timeout on this iteration
  33                 msToWait = INT32_MAX / 2;
  34             } else {
  35                 msToWait = deltaSec * 1000 + deltaNsec / 1000;
  36             }
  37         }
  38
  39         if(msToWait < 0) {
  40             return thrd_timeout;
  41         }
  42
  43         DWORD rv = WaitForSingleObject(mtx->_WaitEvHandle, msToWait);
  44         if(rv != WAIT_OBJECT_0 && rv != WAIT_TIMEOUT)
  45             return thrd_error;
  46     }
  47 }
  48 #endif
  49
  50 #ifdef TEST
  51 #include "_PDCLIB_test.h"
  52
  53 int main( void )
  54 {
  55     return TEST_RESULTS;
  56 }
  57
  58 #endif