cxtsttim.c

上传一个带源代码的嵌入式实时多任务操作系统CMX

/*********************************************************

Copyright (c) CMX Company. 1999. All rights reserved

*********************************************************/
/* version 5.30 */

#define CMXMODULE 1

#include <cxfuncs.h>	/* get cmx include header file */
#include <cxextern.h>	/* get cmx include header file */

#if (defined(CMXTRACKER) || defined(WINTRACKER))
#include <cmxtrack.h>	/* get cmx include header file */
#endif

/**************************************************************
 The following will place a task into the doubly linked list of
 tasks that are waiting on time, if the CMX function was called
 specifying a time wait period of non 0 (zero). Also the task
 will be put to sleep, for the entity that the task was looking
 for, was not present at the time of the function call.
**************************************************************/
byte K_I_Time_Common(word16 timecnt,byte STATE)
{
	activetcb->tcbtimer = timecnt;	/* load task time counter with proper time */
	activetcb->tcbstate = STATE;	 /* put task to sleep, idicating why */
	if (timecnt)	/* put into timer chain ?? */
		{
		/* let task sleep, indicating why and also waiting on time */
		activetcb->tcbstate |= TIME;
		/* place into the doubly linked list. */
		if (tsk_timer_lnk->ftlink != (tcbpointer)tsk_timer_lnk)	
			{
			activetcb->ftlink = tsk_timer_lnk->btlink->ftlink;
			tsk_timer_lnk->btlink->ftlink = activetcb;
			activetcb->btlink = tsk_timer_lnk->btlink;
			}
		else
			{
			activetcb->ftlink = activetcb->btlink = (tcbpointer)tsk_timer_lnk;
			tsk_timer_lnk->ftlink = activetcb;
			}
		tsk_timer_lnk->btlink = activetcb;
		}
	PREEMPTED;	/* set the preempted scheduling flag */
	K_I_Func_Return();	/* release task block */

	/* the task WILL return to here, when it resumes execution. */
	K_I_Disable_Sched();	/* set lock out count. */
	if (activetcb->tcbtimer)	/* see if timer non 0. */
		{
		/* if so, remove from link list. */
		activetcb->ftlink->btlink = activetcb->btlink;
		activetcb->btlink->ftlink = activetcb->ftlink;
		}
	/* see if task was woken, because the thing it was waiting for happened,
		or that the time period specified has elapsed */
	if (activetcb->tcbstate & TIME_EXPIRED)
		{
		K_I_Func_Return();	/* release task block */
		return(K_TIMEOUT);	/* return the warning: that the time period expired */
		}
	else
		{
		K_I_Func_Return();	/* release task block */
		return(K_OK);	/* return good status */
		}
}