source: rtems/c/src/exec/posix/src/ptimer1.c @ 16ce86f9

4.104.114.84.95
Last change on this file since 16ce86f9 was 16ce86f9, checked in by Joel Sherrill <joel.sherrill@…>, on 08/15/00 at 13:00:01

2000-08-15 Joel Sherrill <joel@…>

  • posix/src/ptimer1.c (timer_settime): Converted use of rtems_clock_get to use SuperCore? _TOD_Current variable.
  • Property mode set to 100644
File size: 23.1 KB
Line 
1/*
2 *  ptimer.c,v 1.1 1996/06/03 16:29:58 joel Exp
3 */
4 
5#include <assert.h>
6#include <time.h>
7#include <errno.h>
8
9#include <rtems/system.h>
10#include <rtems/score/isr.h>
11#include <rtems/score/thread.h>
12#include <rtems/score/tod.h>
13
14#include <rtems/posix/time.h>
15
16/************************************/
17/* These includes are now necessary */
18/************************************/
19
20#include <sys/features.h>
21#include <rtems/rtems/status.h>
22#include <rtems/rtems/types.h>
23#include <rtems/rtems/timer.h>
24#include <rtems/rtems/clock.h>
25#include <rtems/posix/psignal.h>
26#include <rtems/score/wkspace.h>
27#include <pthread.h>
28#include <stdio.h>
29#include <signal.h>
30
31#include <rtems/posix/timer.h>
32
33/*****************************/
34/* End of necessary includes */
35/*****************************/
36
37/* ************
38 * Constants
39 * ************/
40
41/*
42#define DEBUG_MESSAGES
43 */
44
45/*
46 * Data for the signals
47 */
48
49struct sigaction signal_inf[SIGRTMAX];
50
51/***********************************
52 * Definition of Internal Functions
53 ***********************************/
54
55/* ***************************************************************************
56 * PRINT_MSG_S
57 *
58 *  Description: This function write a message in the display.
59 *               It is used for debugging and all the calls must be deleted
60 *               when the tests finish
61 * ***************************************************************************/
62
63static void PRINT_MSG_S ( char *msg )
64{
65
66#ifdef DEBUG_MESSAGES
67   printf("%s\n", msg);
68#endif
69
70}
71
72/* ***************************************************************************
73 * PRINT_ERRNO_S
74 *
75 *  Description: Print the value of the global variable errno in the display
76 * ***************************************************************************/
77
78static void PRINT_ERRNO_S ()
79{
80#ifdef DEBUG_MESSAGES
81  switch (errno)
82  {
83     case EINVAL:
84       PRINT_MSG_S ( "errno EINVAL"); break;
85     case EPERM:
86       PRINT_MSG_S ( "errno EPERM"); break;
87     case ESRCH:
88       PRINT_MSG_S ( "errno ESRCH"); break;
89     case EAGAIN:
90       PRINT_MSG_S ( "errno EAGAIN"); break;
91     default :
92       printf ("errno: %d\n", errno);
93       break;
94  }
95#endif
96}
97 
98/* ***************************************************************************
99 * TIMER_INITIALIZE_S
100 *
101 *  Description: Initialize the data of a timer
102 * ***************************************************************************/
103
104extern void TIMER_INITIALIZE_S ( int timer_pos );
105
106/* ***************************************************************************
107 * _POSIX_Timer_Manager_initialization
108 *
109 *  Description: Initialize the internal structure in which the data of all
110 *               the timers are stored
111 * ***************************************************************************/
112
113/* split to reduce minimum size */
114
115/* ***************************************************************************
116 * FIRST_FREE_POSITION_F
117 *
118 *  Description: Returns the first free position in the table of timers.
119 *               If there is not a free position, it returns NO_MORE_TIMERS_C
120 * ***************************************************************************/
121
122int FIRST_FREE_POSITION_F ()
123{
124   int index;
125
126   for (index=0; index<timer_max; index++) {
127      if ( timer_struct[index].state == STATE_FREE_C ) {
128         return index;
129      }
130   }
131   
132   /* The function reaches this point only if all the position are occupied */
133
134   return NO_MORE_TIMERS_C;
135}
136
137/* ***************************************************************************
138 * TIMER_POSITION_F
139 *
140 *  Description: Returns the position in the table of timers in which the
141 *               data of the timer are stored.
142 *               If the timer identifier does not exist, it returns
143 *               BAD_TIMER_C
144 * ***************************************************************************/
145
146int TIMER_POSITION_F ( timer_t timer_id )
147{
148  int index;
149
150  for (index=0; index<timer_max; index++ ) {
151
152     /* Looks for the position of the timer. The timer must exist and the
153      * position can not be free */
154     if ( ( timer_struct[index].timer_id == timer_id ) &&
155          ( timer_struct[index].state != STATE_FREE_C ) ) {
156        return index;
157     }
158  }
159
160  /* If the function reaches this point is because the timer identifier
161   * is not correct */
162
163   return BAD_TIMER_C;
164
165}
166
167/* ***************************************************************************
168 * COPY_ITIMERSPEC_S
169 *
170 *  Description: Does a copy of a variable of type struct itimerspec 
171 * ***************************************************************************/
172
173void COPY_ITIMERSPEC_S ( const struct itimerspec *source,
174                         struct itimerspec *target )
175{
176
177   target->it_value.tv_sec     = source->it_value.tv_sec;
178   target->it_value.tv_nsec    = source->it_value.tv_nsec;
179   target->it_interval.tv_sec  = source->it_interval.tv_sec;
180   target->it_interval.tv_nsec = source->it_interval.tv_nsec;
181
182}
183
184/* ***************************************************************************
185 * ITIMERSPEC_TO_RTEMS_TIME_OF_DAY_S
186 *
187 *  Description: This function converts the data of a structure itimerspec
188 *               into structure rtems_time_of_day
189 * ***************************************************************************/
190
191void ITIMERSPEC_TO_RTEMS_TIME_OF_DAY_S
192   ( const struct itimerspec *itimer, rtems_time_of_day *rtems_time )
193{
194   unsigned long int seconds;
195
196   /* The leap years and the months with 28, 29 or 31 days have not been
197    * considerated. It will be made in the future */
198
199   seconds            = itimer->it_value.tv_sec;
200
201   rtems_time->year   = seconds / SECONDS_PER_YEAR_C;
202   seconds            = seconds % SECONDS_PER_YEAR_C;
203
204   rtems_time->month  = seconds / SECONDS_PER_MONTH_C;
205   seconds            = seconds % SECONDS_PER_MONTH_C;
206
207   rtems_time->day    = seconds / SECONDS_PER_DAY_C;
208   seconds            = seconds % SECONDS_PER_DAY_C;
209
210   rtems_time->hour   = seconds / SECONDS_PER_HOUR_C;
211   seconds            = seconds % SECONDS_PER_HOUR_C;
212
213   rtems_time->minute = seconds / SECONDS_PER_MINUTE_C;
214   seconds            = seconds % SECONDS_PER_MINUTE_C;
215
216   rtems_time->second = seconds;
217
218   rtems_time->ticks  = ( itimer->it_value.tv_nsec * SEC_TO_TICKS_C ) /
219                        NSEC_PER_SEC_C;
220
221}
222
223
224/* ***************************************************************************
225 * FIRE_TIMER_S
226 *
227 *  Description: This is the operation that is ran when a timer expires
228 * ***************************************************************************/
229
230
231rtems_timer_service_routine FIRE_TIMER_S (rtems_id timer, void *data)
232{
233  int               timer_pos;  /* Position in the table of the timer that   
234                                 *  has expirated                            */
235  rtems_status_code return_v;   /* Return value of rtems_timer_fire_after    */
236  int               sig_number; /* Number of the signal to send              */
237
238 
239  /* The position of the table of timers that contains the data of the
240   * expired timer will be stored in "timer_pos". In theory a timer can not
241   * expire if it has not been created or has been deleted */
242
243  PRINT_MSG_S ("FIRE_TIMER_S");
244
245  timer_pos = TIMER_POSITION_F(timer);
246
247  /* Increases the number of expiration of the timer in one unit. */
248  timer_struct[timer_pos].overrun = timer_struct[timer_pos].overrun + 1;
249
250
251  if ( ( timer_struct[timer_pos].timer_data.it_interval.tv_sec  != 0 ) ||
252       ( timer_struct[timer_pos].timer_data.it_interval.tv_nsec != 0 ) ) {
253
254     /* The timer must be reprogrammed */
255
256     return_v = rtems_timer_fire_after ( timer,
257                                        timer_struct[timer_pos].ticks,
258                                        FIRE_TIMER_S,
259                                        NULL );
260
261     /* Stores the time when the timer was started again */
262
263     timer_struct[timer_pos].time = _TOD_Current;
264     
265     /* The state has not to be actualized, because nothing modifies it */
266
267     timer_struct[timer_pos].state = STATE_CREATE_RUN_C;
268
269  } else {
270     /* Indicates that the timer is stopped */
271 
272     timer_struct[timer_pos].state = STATE_CREATE_STOP_C;
273
274  }
275
276  /*
277   * The sending of the signal to the process running the handling function
278   * specified for that signal is simulated
279   */
280
281  sig_number = timer_struct[timer_pos].inf.sigev_signo;
282
283  if( pthread_kill ( timer_struct[timer_pos].thread_id ,
284                     timer_struct[timer_pos].inf.sigev_signo ) ) {
285     PRINT_MSG_S ("ERROR_PTHREAD_KILL");
286  } else {
287     PRINT_MSG_S ("SUCCESS_PTHREAD_KILL");
288  }
289
290  /*
291   * After the signal handler returns, the count of expirations of the
292   * timer must be set to 0.
293   */
294
295  timer_struct[timer_pos].overrun = 0;
296
297}
298
299/* *********************************************************************
300 *  14.2.2 Create a Per-Process Timer, P1003.1b-1993, p. 264
301 * ********************************************************************/
302
303/* **************
304 * timer_create
305 * **************/
306
307int timer_create(
308  clockid_t        clock_id,
309  struct sigevent *evp,
310  timer_t         *timerid
311)
312{
313
314  rtems_status_code return_v;  /* return value of the operation    */
315  rtems_id          timer_id;  /* created timer identifier         */
316  int               timer_pos; /* Position in the table of timers  */
317
318 /*
319  * The data of the structure evp are checked in order to verify if they
320  * are coherent.
321  */
322
323  if (evp != NULL) {
324     /* The structure has data */
325
326     if ( ( evp->sigev_notify != SIGEV_NONE ) &&
327          ( evp->sigev_notify != SIGEV_SIGNAL ) ) {
328       /* The value of the field sigev_notify is not valid */
329
330       return (-1);
331
332     }
333  }
334 
335 /*
336  * A timer is created using the primitive rtems_timer_create
337  */
338
339  return_v = rtems_timer_create ( clock_id, &timer_id );
340
341  switch (return_v) {
342     case RTEMS_SUCCESSFUL :
343
344       PRINT_MSG_S("SUCCESS: rtems create timer RTEMS_SUCCESSFUL");
345     
346       /*
347        * The timer has been created properly
348        */
349 
350        /* Obtains the first free position in the table of timers */
351
352        timer_pos = FIRST_FREE_POSITION_F();
353
354        if ( timer_pos == NO_MORE_TIMERS_C ) {
355           /* There is not position for another timers in spite of RTEMS
356            * supports it. It will necessaty to increase the structure used */
357
358           errno = EAGAIN;
359
360           return -1;
361        }
362
363        /* Exit parameter */
364
365        *timerid  = timer_id;
366
367        /* The data of the created timer are stored to use them later */
368
369        timer_struct[timer_pos].state     = STATE_CREATE_NEW_C;
370
371        /* NEW VERSION*/
372        timer_struct[timer_pos].thread_id = pthread_self ();
373       
374
375        if ( evp != NULL ) {
376
377           timer_struct[timer_pos].inf.sigev_notify = evp->sigev_notify;
378           timer_struct[timer_pos].inf.sigev_signo  = evp->sigev_signo;
379           timer_struct[timer_pos].inf.sigev_value  = evp->sigev_value;
380
381        }
382
383
384        timer_struct[timer_pos].timer_id = timer_id;
385
386        timer_struct[timer_pos].overrun  = 0;
387
388        timer_struct[timer_pos].timer_data.it_value.tv_sec     = 0;
389        timer_struct[timer_pos].timer_data.it_value.tv_nsec    = 0;
390        timer_struct[timer_pos].timer_data.it_interval.tv_sec  = 0;
391        timer_struct[timer_pos].timer_data.it_interval.tv_nsec = 0;
392
393        return 0;
394   
395
396     case RTEMS_INVALID_NAME : /* The assigned name is not valid */
397
398       PRINT_MSG_S ("ERROR: rtems create timer RTEMS_INVALID_NAME");
399
400       errno = EINVAL;
401       return (-1);
402
403
404     case RTEMS_TOO_MANY :
405
406       PRINT_MSG_S ("ERROR: rtems create timer RTEMS_TOO_MANY ");
407 
408       /* There has been created too much timers for the same process */
409
410       errno = EAGAIN;
411
412       return (-1);
413     
414     default :
415
416       /*
417        * Does nothing. It only returns the error without assigning a value
418        * to errno. In theory, it can not happen because the call to
419        * rtems_timer_create can not return other different value.
420        */
421
422       return (-1);
423
424  }
425
426  /*
427   * The next sentence is used to avoid singular situations
428   */
429
430  return (-1);
431
432}
433
434/*
435 *  14.2.3 Delete a Per_process Timer, P1003.1b-1993, p. 266
436 */
437
438int timer_delete(
439  timer_t timerid
440)
441{
442 
443 /*
444  * IDEA: This function must probably stop the timer first and then delete it
445  *
446  *       It will have to do a call to rtems_timer_cancel and then another
447  *       call to rtems_timer_delete.
448  *       The call to rtems_timer_delete will be probably unnecessary,
449  *       because rtems_timer_delete stops the timer before deleting it.
450  */
451
452  int               timer_pos;
453  rtems_status_code status;
454
455
456   /* First the position in the table of timers is obtained */
457
458   timer_pos = TIMER_POSITION_F ( timerid );
459
460   if ( timer_pos == BAD_TIMER_C ) {
461      /* The timer identifier is erroneus */
462
463      errno = EINVAL;
464      return -1;
465   }
466
467   /* The timer is deleted */
468
469   status = rtems_timer_delete ( timerid );
470
471   if ( status == RTEMS_INVALID_ID ) {
472      /* The timer identifier is erroneus */
473
474      errno = EINVAL;
475      return -1;
476   }
477
478   /* Initializes the data of the timer */
479
480   TIMER_INITIALIZE_S ( timer_pos );
481
482   return 0;
483}
484
485/*
486 *  14.2.4 Per-Process Timers, P1003.1b-1993, p. 267
487 */
488
489/* **************
490 * timer_settime
491 * **************/
492
493
494int timer_settime(
495  timer_t                  timerid,
496  int                      flags,
497  const struct itimerspec *value,
498  struct itimerspec       *ovalue
499)
500{
501
502   rtems_status_code return_v;   /* Return of the calls to RTEMS        */
503   int               timer_pos;  /* Position of the timer in the table  */
504   rtems_time_of_day rtems_time; /* Time in RTEMS                       */
505   
506
507   /* First the position in the table of timers is obtained */
508
509   timer_pos = TIMER_POSITION_F ( timerid );
510
511   if ( timer_pos == BAD_TIMER_C ) {
512      /* The timer identifier is erroneus */
513
514      errno = EINVAL;
515      return -1;
516   }
517
518   if ( value == NULL ) {
519     /* The stucture of times of the timer is free, and then returns an
520        error but the variable errno is not actualized */
521
522     /* errno = ?????? */
523
524     return -1;
525   }
526
527   /* If the function reaches this point, then it will be necessary to do
528    * something with the structure of times of the timer: to stop, start
529    * or start it again */
530
531   /* First, it verifies if the timer must be stopped */
532
533   if ( value->it_value.tv_sec == 0 && value->it_value.tv_nsec == 0 ) {
534      /* The timer is stopped */
535
536      return_v = rtems_timer_cancel ( timerid );
537
538      /* The old data of the timer are returned */
539
540      if ( ovalue )
541        COPY_ITIMERSPEC_S ( &timer_struct[timer_pos].timer_data, ovalue );
542
543      /* The new data are set */
544
545      COPY_ITIMERSPEC_S ( value, &timer_struct[timer_pos].timer_data );
546
547      /* Indicates that the timer is created and stopped */
548 
549      timer_struct[timer_pos].state = STATE_CREATE_STOP_C;
550
551      /* Returns with success */
552
553      return 0;
554   }
555
556   /*
557    * If the function reaches this point, then the timer will have to be
558    * initialized with new values: to start it or start it again
559    */
560 
561   /* First, it verifies if the structure "value" is correct */
562
563    if ( ( value->it_value.tv_nsec > MAX_NSEC_C ) ||
564         ( value->it_value.tv_nsec < MIN_NSEC_C ) ) {
565       /* The number of nanoseconds is not correct */
566
567       errno = EINVAL;
568
569       return -1;
570    }
571
572   /* Then, "value" must be converted from seconds and nanoseconds to clock
573    * ticks, to use it in the calls to RTEMS */
574
575   /* It is also necessary to take in account if the time is absolute
576    * or relative */
577
578   switch (flags) {
579      case TIMER_ABSTIME:
580
581        /* The fire time is absolute:
582         * It has to use "rtems_time_fire_when" */
583
584        /* First, it converts from struct itimerspec to rtems_time_of_day */
585
586        ITIMERSPEC_TO_RTEMS_TIME_OF_DAY_S ( value, &rtems_time );
587
588        return_v = rtems_timer_fire_when ( timerid, &rtems_time, FIRE_TIMER_S, NULL);
589
590        switch ( return_v ) {
591           case RTEMS_SUCCESSFUL:
592
593              PRINT_MSG_S ("SUCCESS: timer_settime RTEMS_SUCCESSFUL");
594
595              /* The timer has been started and is running */
596
597              /* Actualizes the data of the structure and
598               * returns the old ones in "ovalue" */
599
600              if ( ovalue )
601                COPY_ITIMERSPEC_S ( &timer_struct[timer_pos].timer_data, ovalue );
602
603              COPY_ITIMERSPEC_S ( value, &timer_struct[timer_pos].timer_data );
604 
605              /* It indicates that the time is running */
606
607              timer_struct[timer_pos].state = STATE_CREATE_RUN_C;
608
609              /* Stores the time in which the timer was started again */
610
611              timer_struct[timer_pos].time = _TOD_Current;
612              return 0;
613
614              break;
615
616           case RTEMS_INVALID_ID:
617
618              PRINT_MSG_S ("ERROR: timer_settime RTEMS_INVALID_ID");
619              break;
620
621           case RTEMS_NOT_DEFINED:
622
623              PRINT_MSG_S ("ERROR: timer_settime RTEMS_NOT_DEFINED");
624              break;
625
626           case RTEMS_INVALID_CLOCK:
627
628              PRINT_MSG_S ("ERROR: timer_settime RTEMS_INVALID_CLOCK");
629              break;
630
631           default:
632
633       
634        }
635     
636        break;
637
638      case TIMER_RELATIVE_C:
639
640        /* The fire time is relative:
641         * It has to use "rtems_time_fire_after" */
642
643        /* First, it converts from seconds and nanoseconds to ticks */
644
645        /* The form in which this operation is done can produce a lost
646         * of precision of 1 second */
647 
648/*      This is the process to convert from nanoseconds to ticks
649 *
650 *      There is a tick every 10 miliseconds, then the nanoseconds are
651 *      divided between 10**7. The result of this operation will be the
652 *      number of ticks
653 */
654
655        timer_struct[timer_pos].ticks =
656             ( SEC_TO_TICKS_C * value->it_value.tv_sec ) +
657             ( value->it_value.tv_nsec / ( 1000 * 1000 * 10 ) );
658
659        return_v = rtems_timer_fire_after ( timerid,
660                                           timer_struct[timer_pos].ticks,
661                                           FIRE_TIMER_S,
662                                           NULL );
663
664        switch (return_v) {
665           case RTEMS_SUCCESSFUL:
666
667              PRINT_MSG_S ( "SUCCESS: timer_settime RTEMS_SUCCESSFUL");
668             
669              /* The timer has been started and is running */
670
671              /* Actualizes the data of the structure and
672               * returns the old ones in "ovalue" */
673
674              if ( ovalue )
675                COPY_ITIMERSPEC_S ( &timer_struct[timer_pos].timer_data, ovalue );
676
677              COPY_ITIMERSPEC_S ( value, &timer_struct[timer_pos].timer_data );
678 
679              /* It indicates that the time is running */
680
681              timer_struct[timer_pos].state = STATE_CREATE_RUN_C;
682
683              /* Stores the time in which the timer was started again */
684
685              timer_struct[timer_pos].time = _TOD_Current;
686 
687              return 0;
688
689              break;
690
691           case RTEMS_INVALID_ID:
692
693              PRINT_MSG_S ( "ERROR: timer_settime RTEMS_INVALID_ID");
694
695              /* The timer identifier is not correct. In theory, this
696               * situation can not occur, but the solution is easy */
697
698              errno = EINVAL;
699
700              return -1;
701
702              break;
703
704           case RTEMS_INVALID_NUMBER:
705
706              PRINT_MSG_S ( "ERROR: timer_settime RTEMS_INVALID_NUMBER");
707
708              /* In this case, RTEMS fails because the values of timing
709               * are incorrect */
710
711              /*
712               * I do not know if errno must be actualized
713               *
714               * errno = EINVAL;
715               */
716
717              return -1;
718
719              break;
720           
721           default:
722        }
723
724        break;
725
726      default:
727
728        /* It does nothing, although it will be probably necessary to
729         * return an error */
730
731   }
732
733   /* To avoid problems */
734
735   return 0;
736
737}
738
739
740/*
741 *  14.2.4 Per-Process Timers, P1003.1b-1993, p. 267
742 */
743
744/* **************
745 * timer_gettime
746 * **************/
747
748int timer_gettime(
749  timer_t            timerid,
750  struct itimerspec *value
751)
752{
753
754 /*
755  * IDEA:  This function does not use functions of RTEMS to the handle
756  *        of timers. It uses some functions for managing the time.
757  *
758  *        A possible form to do this is the following:
759  *
760  *          - When a timer is initialized, the value of the time in
761  *            that moment is stored.
762  *          - When this function is called, it returns the difference
763  *            between the current time and the initialization time.
764  */
765 
766  rtems_time_of_day current_time;
767  rtems_status_code return_v;
768  int               timer_pos;
769  unsigned32        hours;
770  unsigned32        minutes;
771  unsigned32        seconds;
772  unsigned32        ticks;
773  unsigned32        nanosec;
774 
775
776  /* Reads the current time */
777
778  current_time = _TOD_Current;
779
780  timer_pos = TIMER_POSITION_F ( timerid );
781
782  if ( timer_pos == BAD_TIMER_C ) {
783
784     /* The timer identifier is erroneus */ 
785
786     errno = EINVAL;
787
788     return (-1);
789
790  }
791
792  /* Calculates the difference between the start time of the timer and
793   * the current one */
794
795  hours    = current_time.hour - timer_struct[timer_pos].time.hour;
796
797  if ( current_time.minute < timer_struct[timer_pos].time.minute ) {
798     minutes = 60 - timer_struct[timer_pos].time.minute + current_time.minute;
799     hours--;
800  } else {
801     minutes = current_time.minute - timer_struct[timer_pos].time.minute;
802  }
803   
804  if ( current_time.second < timer_struct[timer_pos].time.second ) {
805     seconds = 60 - timer_struct[timer_pos].time.second + current_time.second;
806     minutes--;
807  } else {
808     seconds = current_time.second - timer_struct[timer_pos].time.second;
809  }
810
811  if ( current_time.ticks < timer_struct[timer_pos].time.ticks ) {
812     ticks = 100 - timer_struct[timer_pos].time.ticks + current_time.ticks;
813     seconds--;
814  } else {
815     ticks = current_time.ticks - timer_struct[timer_pos].time.ticks;
816  }
817
818  /* The time that the timer is running is calculated */
819  seconds = hours   * 60 * 60 +
820            minutes * 60      +
821            seconds;
822
823  nanosec  = ticks * 10 *  /* msec     */
824             1000  *       /* microsec */
825             1000;         /* nanosec  */
826
827 
828  /* Calculates the time left before the timer finishes */
829 
830  value->it_value.tv_sec =
831    timer_struct[timer_pos].timer_data.it_value.tv_sec - seconds;
832 
833  value->it_value.tv_nsec =
834    timer_struct[timer_pos].timer_data.it_value.tv_nsec - nanosec;
835
836
837  value->it_interval.tv_sec  =
838    timer_struct[timer_pos].timer_data.it_interval.tv_sec;
839  value->it_interval.tv_nsec =
840    timer_struct[timer_pos].timer_data.it_interval.tv_nsec;
841 
842
843  return 0;
844
845}
846
847/*
848 *  14.2.4 Per-Process Timers, P1003.1b-1993, p. 267
849 */
850
851/* *****************
852 * timer_getoverrun
853 * *****************/
854
855int timer_getoverrun(
856  timer_t   timerid
857)
858{
859
860 /*
861  * IDEA: This function must count the times the timer expires.
862  *   
863  *       The expiration of a timer must increase by one a counter.
864  *       After the signal handler associated to the timer finishs
865  *       its execution, FIRE_TIMER_S will have to set this counter to 0.
866  */
867
868  int timer_pos; /* Position of the timer in the structure     */
869  int overrun;   /* Overflow count                             */
870
871
872  timer_pos = TIMER_POSITION_F ( timerid );
873
874  if ( timer_pos == BAD_TIMER_C ) {
875     /* The timer identifier is erroneus */
876
877     errno = EINVAL;
878
879     return -1;
880  }
881
882  /* The overflow count of the timer is stored in "overrun" */
883
884  overrun = timer_struct[timer_pos].overrun;
885
886  /* It is set to 0 */
887
888  timer_struct[timer_pos].overrun = 0;
889
890  return overrun;
891
892}
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