The microc don't do anothers tasks

Hi, I was reading the example code "hello_ucosii.c", but when I modify the code he made only the task1. My code modified is:

# include <stdio.h># include "includes.h"# include "system.h"# include <unistd.h># include "altera_avalon_pio_regs.h"# include "alt_types.h"
/* Definition of Task Stacks */# define   TASK_STACKSIZE       2048
OS_STK    task1_stk;
OS_STK    task2_stk;
/* Definition of Task Priorities */
# define TASK1_PRIORITY      1# define TASK2_PRIORITY      2
/*Subroutine for wait a necessary time for each level of PWM signal*/
int count(float n, float f)
{
    int i;
    float a, x;
    x=(1/f)*2000000;
    a=n*x;
        for(i=1; i<=a; i++)
        {
            x=0;
        }
    return n;
}
/* Gerate a PWM Signal */
void task1(void* pdata)
{
    int signal, control;
    float f, n;
    f=100;//22Hz in practice
    while(1)
    {
           control=IORD_ALTERA_AVALON_PIO_DATA(DUTY_PIO_BASE);
           
           if(control==0x0)
           {
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
           }
                            
           if(control==0x1)
           {
                            n=0.25*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.25)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
            }
                            
           if(control==0x3)
           {
                            n=0.50*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.50)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
           }
                            
           if(control==0x7)
           {
                            n=0.75*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.75)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
            }
                            
           if(control==0xf)
           {
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
           }
                            
     }             
     
}
/* Prints "Hello World" and sleeps for three seconds */
void task2(void* pdata)
{
  while (1)
  { 
    printf("Hello from task2\n");
    OSTimeDlyHMSM(0, 0, 3, 0);
  }
}
/* The main function creates two task and starts multi-tasking */
int main(void)
{
  
  OSTaskCreateExt(task1,
                  NULL,
                  (void *)&task1_stk,
                  TASK1_PRIORITY,
                  TASK1_PRIORITY,
                  task1_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
              
               
  OSTaskCreateExt(task2,
                  NULL,
                  (void *)&task2_stk,
                  TASK2_PRIORITY,
                  TASK2_PRIORITY,
                  task2_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
  OSStart();
  return 0;
}