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      1 /*
      2  * pthreads_delay_np.c
      3  *
      4  * Description:
      5  * This translation unit implements non-portable 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 
     40 /*
     41  * pthread_delay_np
     42  *
     43  * DESCRIPTION
     44  *
     45  *       This routine causes a thread to delay execution for a specific period of time.
     46  *       This period ends at the current time plus the specified interval. The routine
     47  *       will not return before the end of the period is reached, but may return an
     48  *       arbitrary amount of time after the period has gone by. This can be due to
     49  *       system load, thread priorities, and system timer granularity.
     50  *
     51  *       Specifying an interval of zero (0) seconds and zero (0) nanoseconds is
     52  *       allowed and can be used to force the thread to give up the processor or to
     53  *       deliver a pending cancelation request.
     54  *
     55  *       The timespec structure contains the following two fields:
     56  *
     57  *            tv_sec is an integer number of seconds.
     58  *            tv_nsec is an integer number of nanoseconds.
     59  *
     60  *  Return Values
     61  *
     62  *  If an error condition occurs, this routine returns an integer value indicating
     63  *  the type of error. Possible return values are as follows:
     64  *
     65  *  0
     66  *           Successful completion.
     67  *  [EINVAL]
     68  *           The value specified by interval is invalid.
     69  *
     70  * Example
     71  *
     72  * The following code segment would wait for 5 and 1/2 seconds
     73  *
     74  *  struct timespec tsWait;
     75  *  int      intRC;
     76  *
     77  *  tsWait.tv_sec  = 5;
     78  *  tsWait.tv_nsec = 500000000L;
     79  *  intRC = pthread_delay_np(&tsWait);
     80  */
     81 int
     82 pthread_delay_np (struct timespec *interval)
     83 {
     84   DWORD wait_time;
     85   DWORD secs_in_millisecs;
     86   DWORD millisecs;
     87   DWORD status;
     88   pthread_t self;
     89   ptw32_thread_t * sp;
     90 
     91   if (interval == NULL)
     92     {
     93       return EINVAL;
     94     }
     95 
     96   if (interval->tv_sec == 0L && interval->tv_nsec == 0L)
     97     {
     98       pthread_testcancel ();
     99       Sleep (0);
    100       pthread_testcancel ();
    101       return (0);
    102     }
    103 
    104   /* convert secs to millisecs */
    105   secs_in_millisecs = (DWORD)interval->tv_sec * 1000L;
    106 
    107   /* convert nanosecs to millisecs (rounding up) */
    108   millisecs = (interval->tv_nsec + 999999L) / 1000000L;
    109 
    110 #if defined(__WATCOMC__)
    111 #pragma disable_message (124)
    112 #endif
    113 
    114   /*
    115    * Most compilers will issue a warning 'comparison always 0'
    116    * because the variable type is unsigned, but we need to keep this
    117    * for some reason I can't recall now.
    118    */
    119   if (0 > (wait_time = secs_in_millisecs + millisecs))
    120     {
    121       return EINVAL;
    122     }
    123 
    124 #if defined(__WATCOMC__)
    125 #pragma enable_message (124)
    126 #endif
    127 
    128   if (NULL == (self = pthread_self ()).p)
    129     {
    130       return ENOMEM;
    131     }
    132 
    133   sp = (ptw32_thread_t *) self.p;
    134 
    135   if (sp->cancelState == PTHREAD_CANCEL_ENABLE)
    136     {
    137       /*
    138        * Async cancelation won't catch us until wait_time is up.
    139        * Deferred cancelation will cancel us immediately.
    140        */
    141       if (WAIT_OBJECT_0 ==
    142 	  (status = WaitForSingleObject (sp->cancelEvent, wait_time)))
    143 	{
    144           ptw32_mcs_local_node_t stateLock;
    145 	  /*
    146 	   * Canceling!
    147 	   */
    148 	  ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);
    149 	  if (sp->state < PThreadStateCanceling)
    150 	    {
    151 	      sp->state = PThreadStateCanceling;
    152 	      sp->cancelState = PTHREAD_CANCEL_DISABLE;
    153 	      ptw32_mcs_lock_release (&stateLock);
    154 
    155 	      ptw32_throw (PTW32_EPS_CANCEL);
    156 	    }
    157 
    158 	  ptw32_mcs_lock_release (&stateLock);
    159 	  return ESRCH;
    160 	}
    161       else if (status != WAIT_TIMEOUT)
    162 	{
    163 	  return EINVAL;
    164 	}
    165     }
    166   else
    167     {
    168       Sleep (wait_time);
    169     }
    170 
    171   return (0);
    172 }
    173