RTOS/TM4C123GH6PM: i am trying to write a program blinking led using semaphore can u share any referance program?

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/*
 *  ======== gpiointerrupt.c ========
 */

/* XDCtools Header files */
#include <xdc/std.h>
#include <xdc/runtime/Error.h>
#include <xdc/runtime/System.h>

/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Semaphore.h>
#include <ti/sysbios/knl/Task.h>

/* TI-RTOS Header files */
#include <ti/drivers/GPIO.h>

/* Example/Board Header files */
#include "Board.h"

/* variable to be read by GUI Composer */
int count = 0;

Semaphore_Handle semHandle;
Task_Handle taskHandle;

/*
 *  ======== gpioButtonFxn0 ========
 *  Callback function for the GPIO interrupt on Board_BUTTON0.
 */
void gpioButtonFxn0(unsigned int index)
{
    /* Clear the GPIO interrupt and toggle an LED */
    //GPIO_toggle(Board_LED0);
    Semaphore_post(semHandle);

    if (count++ == 100) {
        count = 0;
    }
}

/*
 *  ======== gpioButtonFxn1 ========
 *  Callback function for the GPIO interrupt on Board_BUTTON1.
 *  This may not be used for all boards.
 */
void gpioButtonFxn1(unsigned int index)
{
    /* Clear the GPIO interrupt and toggle an LED */
    GPIO_toggle(Board_LED1);

    if (count++ == 100) {
        count = 0;
    }
}

Void myTaskFxn(UArg arg0, UArg arg1)
{
    while(1) {
        Semaphore_pend(semHandle, BIOS_WAIT_FOREVER);
        GPIO_toggle(Board_LED0);
    }
}

/*
 *  ======== main ========
 */
int main(void)
{
    Error_Block eb;

    Error_init(&eb);

    /* Call board init functions */
    Board_initGeneral();
    Board_initGPIO();
    Board_initUART();

    Semaphore_Params semParams;

    /*
     * Use counting semaphore...which is the default, but just to show how
     * to explicit set it.
     */
    Semaphore_Params_init(&semParams);
    semParams.mode = Semaphore_Mode_COUNTING;
    semHandle = Semaphore_create(0, &semParams, &eb);
    if (semHandle == NULL) {
        System_abort("Semaphore_create failed");
    }

    /* Use default params */
    taskHandle = Task_create(myTaskFxn, NULL, &eb);
    if (taskHandle == NULL) {
        System_abort("Task_create failed");
    }

    /* Turn on user LED */
    GPIO_write(Board_LED0, Board_LED_ON);

    System_printf("Starting the GPIO Interrupt example\nSystem provider is set"
                  " to SysMin. Halt the target to view any SysMin contents in"
                  " ROV.\n");
    /* SysMin will only print to the console when you call flush or exit */
    System_flush();

    /* install Button callback */
    GPIO_setCallback(Board_BUTTON0, gpioButtonFxn0);

    /* Enable interrupts */
    GPIO_enableInt(Board_BUTTON0);

    /*
     *  If more than one input pin is available for your device, interrupts
     *  will be enabled on Board_BUTTON1.
     */
    if (Board_BUTTON0 != Board_BUTTON1) {
        /* install Button callback */
        GPIO_setCallback(Board_BUTTON1, gpioButtonFxn1);
        GPIO_enableInt(Board_BUTTON1);
    }

    /* Start BIOS */
    BIOS_start();

    return (0);
}