vxWorks的二值信号量示例

semLib版本vxWorks6.8的源码位置在：\WindRiver3.8\vxworks-6.8\target\usr\src\wind\semLib.c

下面是测试示例：

#include "vxWorks.h"#include "taskLib.h"#include "semLib.h"#include "stdio.h"#include "sysLib.h"SEM_ID semId; LOCAL SEM_ID semId1;            /* semaphore id of binary semaphore 1 */LOCAL SEM_ID semId2;            /* semaphore id of binary semaphore 2 */LOCAL BOOL notDone;                /* flag to indicate completion */LOCAL STATUS taskA ();LOCAL STATUS taskB ();//测试入口STATUS TestBSem(){    notDone = TRUE;     /* semaphore semId1 is availble  after creation*/    if ((semId1 = semBCreate (SEM_Q_PRIORITY, SEM_FULL)) == NULL)    {        perror ("synchronizeDemo: Error in creating semId1 semaphore");        return (ERROR);    }    /* semaphore semId2 is not available  after creation*/    if ((semId2 = semBCreate (SEM_Q_PRIORITY, SEM_EMPTY)) == NULL)    {        perror ("synchronizeDemo: Error in creating semId2 semaphore");        return (ERROR);    }    /* Spwan taskA*/    if (taskSpawn ("tTaskA", 98, 0, 5000, (FUNCPTR) taskA, 0,                    0, 0, 0, 0, 0, 0, 0, 0, 0) == ERROR)    {        perror ("synchronizeDemo: Error in spawning taskA");        return (ERROR);    }    /* Spwan taskB*/    if (taskSpawn ("tTaskB", 98, 0, 5000, (FUNCPTR) taskB, 0,                   0, 0, 0, 0, 0, 0, 0, 0, 0) == ERROR)    {        perror ("synchronizeDemo: Error in spawning taskB");        return (ERROR);    }        /* Polling is not recommended. But used for simple demonstration purpose */    while (notDone)     {        taskDelay (sysClkRateGet());  /* wait here until done */    }    /* Delete the created semaphores */    if (semDelete (semId1) == ERROR)    {        perror ("syncronizeDemo: Error in deleting semId1 semaphore");        return (ERROR);    }    if (semDelete (semId2) == ERROR)    {       perror ("syncronizeDemo: Error in deleting semId1 semaphore");       return (ERROR);    }    printf ("\n\n synchronizeDemo now completed \n");        return (OK);}/***************************************************************************** *  taskA - executes event A first and wakes up taskB to excute event B next *          using binary semaphores for synchronization. * *  RETURNS: OK or ERROR * */LOCAL STATUS taskA (){    int count;    for (count = 0; count < 3; 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()));        printf("taskA: I'm done, taskB can now proceed; Releasing semId2 semaphore\n\n");        if (semGive (semId2) == ERROR)        {            perror ("taskA: Error in semGive");            return (ERROR);        }    }    return (OK);}/***************************************************************************** *  taskB - executes event B first and wakes up taskA to excute event A next *          using binary semaphores for synchronization. * *  RETURNS: OK or ERROR * */LOCAL STATUS taskB()    {    int count;    for (count = 0; count < 3; 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);        }    }    notDone = FALSE;    return (OK);}