b-sync.c

VxWorks中

#include "Vxworks.h"
#include "taskLib.h"
#include "semLib.h"
#include "stdio.h"
#include "sysLib.h"

#define	TASK_PRI		98
#define TASK_STACK_SIZE		5000

LOCAL SEM_ID semId1;
LOCAL SEM_ID semId2;
LOCAL int numTimes=3;
LOCAL BOOL notDone;
LOCAL STATUS taskA();
LOCAL STATUS taskB();



STATUS synchronizeDemo()
{
notDone=TRUE;

if((semId1=semBCreate(SEM_Q_PRIORITY, SEM_FULL))==NULL)
	{
	perror("synchronizeDemo: Error in creating semId1 semaphore");
	return(ERROR);
	}

if((semId2=semBCreate(SEM_Q_PRIORITY, SEM_EMPTY))==NULL)
	{
	perror("synchronizeDemo: Error in creating semId2 semaphore");
	return(ERROR);
	}
printf("\n\n synchronizeDemo Created successful\n");

if(taskSpawn("tTaskA", TASK_PRI, 0, TASK_STACK_SIZE, (FUNCPTR) taskA, 0,0,0,0,0,0,0,0,0,0)==ERROR)
	{
	perror("synchronizeDemo: Error in spawning taskA");
	return(ERROR);
	}
	
if(taskSpawn("tTaskB", TASK_PRI, 0, TASK_STACK_SIZE, (FUNCPTR) taskB, 0,0,0,0,0,0,0,0,0,0)==ERROR)
	{
	perror("synchronizeDemo: Error in spawning taskB");
	return(ERROR);
	}

while(notDone)
	taskDelay(sysClkRateGet());

if(semDelete(semId1)==ERROR)
	{
	perror("syncronizeDemo: Error in deleting semId1 semaphore");
	return(ERROR);
	}
if(semDelete(semId2)==ERROR)
	{
	perror("syncronizeDemo: Error in deleting semId2 semaphore");
	return(ERROR);
	}
printf("\n\n synchronizeDemo now completed\n");
return(OK);
}

LOCAL STATUS taskA()
	{
	int count;

	for(count=0;count<numTimes;count++)
		{
		if(semTake(semId1, WAIT_FOREVER)==ERROR)
			{
			perror("taskA: Error in semTake");
			return(ERROR);
			}
		printf("taskA: Started first by taking the semId1 semaphore %d times\n",(count+1));
		printf("This is task <%s>: Event A now done\n", taskName(taskIdSelf()));
		if(semGive(semId2)==ERROR)
			{
			perror("taskA: Error in semGive");
			return(ERROR);
			}
		}
		return(OK);
	}

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

LOCAL STATUS taskB()
	{
	int count;

	for(count=0;count<numTimes;count++)
		{
		if(semTake(semId2, WAIT_FOREVER)==ERROR)
			{
			perror("taskB: Error in semTake");
			return(ERROR);
			}
		printf("taskB: synchronized with taskA's release of semID2 %d times\n", (count+1));
		printf("This is task <%s>:Event B now done\n", taskName(taskIdSelf()));
		printf("taskB: I'm done, taskA can now proceed; Releasing semId1 semaphore\n\n\n");
		if(semGive(semId1)==ERROR)
			{

			perror("taskB: Error in semGive");
			return(ERROR);
			}
			printf("hello!");
		}
		notDone=FALSE;
		return(OK);
	}