s7_inversion.c

来自「tornado2.2开发」· C语言 代码 · 共 81 行

#include "vxWorks.h"
#include "taskLib.h"
#include "semLib.h"
#include "stdio.h"

#define ITER 3
#define HIGH 102
#define MID 103
#define LOW 104
#define LONG_TIME (1<<25)
SEM_ID semMutex;

static void prioLow(void)
{
    int i,j;
    for (i=0;i<ITER;i++)
    {
        semTake(semMutex,WAIT_FOREVER);
        printf("Low priority task locks semaphore.\n");
        for (j=0;j<LONG_TIME;j++)
        {}
        printf("Low priority task unlocks semaphore.\n");
        semGive(semMutex);
    }
    printf("....................Low priority task exited.\n");
}

static void prioMid(void)
{
    int i;
    taskDelay(7);
    for (i=0;i<LONG_TIME*10;i++)
    {
        if ((i%LONG_TIME)==0)
        {
             printf("Mid priority task running.\n");            
        }
    }
    printf("----------------------Mid priority task exited.\n");

}

static void prioHigh(void)
{
    int i,j;
    taskDelay(20);
    for (i=0;i<ITER;i++)
    {
        printf("High priority task trys to lock semaphore.\n");
        semTake(semMutex,WAIT_FOREVER);
        printf("High priority task locks semaphore.\n");
        for (j=0;j<LONG_TIME;j++)
        {}
        printf("High priority task unlocks semaphore.\n");
        semGive(semMutex);
    }
    printf("....................High priority task exited.\n");
}

void s7_inversion(void)
{
    int i,low,mid,high;
    logMsg("\n\n.......##RUNNING##.......\n\n\n\n\n",0,0,0,0,0,0);
    semMutex = semMCreate(SEM_Q_PRIORITY|SEM_INVERSION_SAFE);
    if ((low = taskSpawn("low",LOW,0x100,20000,
          (FUNCPTR)prioLow,0,0,0,0,0,0,0,0,0,0))==ERROR)
    { 
        logMsg("taskSpawn prioLow failed.\n",0,0,0,0,0,0);
    }
    if ((mid= taskSpawn("mid",MID,0x100,20000,
          (FUNCPTR)prioMid,0,0,0,0,0,0,0,0,0,0))==ERROR)
    { 
        logMsg("taskSpawn prioMid failed.\n",0,0,0,0,0,0);
    }
    if ((high = taskSpawn("high",HIGH,0x100,20000,
          (FUNCPTR)prioHigh,0,0,0,0,0,0,0,0,0,0))==ERROR)
    { 
        logMsg("taskSpawn prioHigh failed.\n",0,0,0,0,0,0);
    }
}