task2.c

三个semephor实现的进程之间通讯

/*
  Copyright(c) Micro-Star International Co. Ltd.
  The copyright to the computer program(s) herein is the property of
  Micro-Star International Co. Ltd.
  The program(s) may be used and/or copied only with the written
  permission of MSI or in accordance with the terms and conditions
  stipulated in the agreement/contract under which the program(s) have
  been supplied.
*/
/*
 * MODULE FILE NAME: TASK2.C
 *
 * DESCRIPTION:
 *
 *
 * NOTES:
 *
 *
 * HISTORY:
 *
 * $Log$
 
/* INCLUDE FILES */

/* system-wise, independent */
#include "syslib.h"
#include "sys_hdr/sys_type.h"
#include "sys_hdr/uitron.h"
#include "sys_bld.h"

/* kernel service */

/* project dependent */

/* third party */

/* other components */

/* this component */
#include "core/task2/hdr/task2.h" 

/*
 * FUNCTION NAME: TASK2_Init
 * PURPOSE:
 *      Initialize for TASK2 operations.
 *
 * INPUT:
 *      None
 * OUTPUT:
 *       None
 * RETURN:
 *       BOOL
 * NOTES:
 *      
 */ 
 

BOOL TASK2_Init(void)
{
	/* LOCAL VARIABLES DECLARATIONS */
	T_CSEM t_csem;      /* semaphore2 */
	ER ercd;
	
	/* Init semaphore */
	t_csem.sematr = TA_TFIFO;
	t_csem.isemcnt = 0;
	t_csem.exinf = SYS_BLD_TASK2_SEM_NAME; /* store task name */
	t_csem.maxsem = 1;

	/* create semaphore sema id SYS_BLD_SMTPC_SEM_ID */
	ercd=cre_sem( SYS_BLD_TASK2_SEM_ID , &t_csem);

	if (ercd!= E_OK)    
    {                                                       
    	printf("TASK2 wait semaphore error %d\n", ercd);   
        return FALSE;                                       
    }
	return TRUE;  
}

/*
 * FUNCTION NAME: TASK2_TskMain
 * PURPOSE:
 *      this is task2 information.
 *
 * INPUT:
 *      None
 * OUTPUT:
 *       None
 * RETURN:
 *       None
 * NOTES:
 *      
 */ 

void TASK2_TskMain(void)
{	
	while(TRUE)
	{
		wai_sem(SYS_BLD_TASK2_SEM_ID);
		printf("\n I'm task B! \n");
        sig_sem(SYS_BLD_TASK3_SEM_ID);
	}
}

/*
 * FUNCTION NAME: TASK2_CreateTask
 * PURPOSE:
 *      Create the task of TASK2 Alerter.
 *
 * INPUT:
 *      None
 * OUTPUT:
 *       None
 * RETURN:
 *      BOOL -- return TRUE/FALSE 
 * NOTES:
 *      
 */ 
BOOL TASK2_CreateTask(void)
{		
	/* LOCAL VARIABLES DECLARATIONS */
	T_CTSK t_ctsk;          /* task2 */ 
	ER ercd2;
    I32  taskid;
  
    /* FUNCTION BODY */

    memset(&t_ctsk, 0 , sizeof(t_ctsk));	

    t_ctsk.task    = (FP)&TASK2_TskMain;
    t_ctsk.itskpri = SYS_BLD_TASK2_TASK_PRIORITY;
    t_ctsk.stksz   = SYS_BLD_GENERIC_STACK_SIZE;
    t_ctsk.tskatr  = TA_HLNG;
    t_ctsk.exinf   = SYS_BLD_TASK2_TASK_NAME; /* assign task name */
    
    ercd2 = cre_tsk( SYS_BLD_TASK2_TASK_ID, &t_ctsk); 
    
    if(ercd2 != E_OK )
    	{
       		printf(" Create Task1 Error ! ercd1 = %d\n",ercd2);
       		return FALSE;
    	}

	ercd2 = sta_tsk (SYS_BLD_TASK2_TASK_ID,0);
     	
	if(ercd2!= E_OK)
		{
			printf(" Start Task1 Error ! ercd = %d\n",ercd2);
			return FALSE;
		} 
	return TRUE;
}