ar_timer.c

Keil开发环境下ARM7内核单片机的ARTX RTOS内核源代码

/*----------------------------------------------------------------------------
 *      A R T X  -  K e r n e l
 *----------------------------------------------------------------------------
 *      Name:    AR_TIMER.C
 *      Purpose: User timer functions
 *      Rev.:    V2.00 / 19-oct-2005
 *----------------------------------------------------------------------------
 *      This code is part of the ARTX-ARM kernel package of Keil Software.
 *      Copyright (c) 2004-2005 Keil Software. All rights reserved. 
 *---------------------------------------------------------------------------*/

#include "Kernel\ARTX_Config.h"

/* ARTX_Config.c */
extern struct OS_XTMR  os_tmr;

/* Mapping of API-type to internal type */
#define p_TMR   ((P_TMR)timer)

/*----------------------------------------------------------------------------
 *      Functions
 *---------------------------------------------------------------------------*/

/*--------------------------- os_tmr_tick -----------------------------------*/

void os_tmr_tick (void) {
   /* Decrement delta count of timer list head. Timers having the value of   */
   /* zero are removed from the list and the callback function is called.    */
   P_TMR p;

   if (os_tmr.next == NULL) {
      return;
      }
   os_tmr.tcnt--;
   while (os_tmr.tcnt == 0 && (p = os_tmr.next) != NULL) {
      /* Call a user provided function to handle an ellapsed timer */
      os_tmr_call (p->info);
      os_tmr.tcnt = p->tcnt;
      os_tmr.next = p->next;
      os_free_TMR (p);
      }
} /* end of os_tmr_tick */

/*--------------------------- os_tmr_create ---------------------------------*/

OS_ID os_tmr_create (U16 tcnt, U16 info)  {
   /* Create an user timer and put it into the chained timer list using      */
   /* a timeout count value of "tcnt". User parameter "info" is used as a    */
   /* parameter for the user provided callback function "os_tmr_call ()".    */
   P_TMR p_tmr, p;
   U32 delta,itcnt = tcnt;

   if (!tcnt)  {
      return (NULL);
      }
   p_tmr = os_alloc_TMR ();
   if (!p_tmr)  {
      return (NULL);
   }
   p_tmr->info = info;
   p = (P_TMR)&os_tmr;
   tsk_lock ();
   delta = p->tcnt;
   while (delta < itcnt && p->next != NULL) {
      p = p->next;
      delta += p->tcnt;
      }
   /* Right place found, insert timer into the list */
   p_tmr->next = p->next;
   p_tmr->tcnt = (U16)(delta - itcnt);
   p->next = p_tmr;
   p->tcnt -= p_tmr->tcnt;
   tsk_unlock ();
   return (p_tmr);
} /* end of os_tmr_create */

/*--------------------------- os_tmr_kill -----------------------------------*/

OS_ID os_tmr_kill (OS_ID timer)  {
   /* Remove user timer from the chained timer list. */
   P_TMR p;

   p = (P_TMR)&os_tmr;
   tsk_lock ();
   /* Search timer list for requested timer */
   while (p->next != timer)  {
      if (p->next == NULL) {
         /* Failed, "timer" is not in the timer list */
         tsk_unlock ();
         return (timer);
         }
      p = p->next;
      }
   /* Timer was found, remove it from the list */
   p->next = p_TMR->next;
   p->tcnt += p_TMR->tcnt;
   os_free_TMR (timer);
   /* Timer killed */
   tsk_unlock ();
   return (NULL);
} /* end of os_tmr_kill */

/*----------------------------------------------------------------------------
 * end of file
 *---------------------------------------------------------------------------*/