two different delay functions in program

#include<reg51.h>    //header file

sbit   LED1     = P2^0;    //LED 1 conncted to port P2 pin 0
sbit   LED2     = P2^1;    //LED 2 conncted to port P2 pin 1
sbit   LED3     = P2^2;    //LED 3 conncted to port P2 pin 2

// prototype function
void DoSomething0(void);
void DoSomething1(void);
void DoSomething2(void);

typedef enum
{
    task1 ,
    task2,
    task3
} my_task_t;

int main(void)
{
my_task_t task;
   switch  (task)
   {
      case task1:
         DoSomething0();
         break;
 
      case task2:
         DoSomething1();
         break;
 
      case task3:
         DoSomething2();
         break;
}

#include<reg51.h>    //header file

sbit   LED1     = P2^0;    //LED 1 conncted to port P2 pin 0
sbit   LED2     = P2^1;    //LED 2 conncted to port P2 pin 1
sbit   LED3     = P2^2;    //LED 3 conncted to port P2 pin 2

// prototype function
void DoSomething0(void);
void DoSomething1(void);
void DoSomething2(void);

typedef enum
{
    task1 ,
    task2,
    task3
} my_task_t;
my_task_ t task;

int main(void)
{
   switch  (task)
   {
      case task1:
          if <task> == task1
         DoSomething0();
         break;
 
      case task2:
        if <task> == task2
       DoSomething1();
         break;
 
      case task3:
          if <task> == task3
         DoSomething2();
         break;
}

#include <stdio.h>
#include <8052.h>
void do_task_one(void), do_task_two(void), do_task_three(void);
enum{
 task1,
 task2,
 task3,
};
void main()
 {
 char my_task = 0;
 
 while(1)
  {
  switch(my_task)
   {
   case task1 : do_task_one(); break;
   case task2 : do_task_two(); break;
   case task3 : do_task_three(); break;
   }
  if(++my_task > 2) my_task = 0;
  }
     }
void do_task_one()
{}
void do_task_two()
{}
void do_task_three()
{}

#include<reg51.h>    //header file

#define  LED1_ON   1
#define  LED1_OFF  0
#define  LED2_ON   1
#define  LED2_OFF  0
#define  LED3_ON   1
#define  LED4_OFF  0

sbit   LED1     = P2^0;    //LED 1 conncted to port P2 pin 0
sbit   LED2     = P2^1;    //LED 2 conncted to port P2 pin 1
sbit   LED3     = P2^2;    //LED 3 conncted to port P2 pin 2
typedef enum
{
    task1,
    task2,
    task3
};
// prototype function
void LED1_Blink(void);
void LED2_Blink(void);
void LED3_Blink(void);
int main(void)
{
   unsigned int task=0;
 
   while(1)
  {
   switch  (task)
   {
      case task1:
         LED1_Blink();
         break;
   
      case task2:
         LED2_Blink();
         break;
   
      case task3:
         LED3_Blink();
         break;     
   }
}
}
void LED1_Blink ()
{
    unsigned int i;
    for (i = 0; i < 1000; i++);
}
void LED2_Blink()
{
    unsigned int j;
    for (j = 0; j < 1500; j++);
}
void LED3_Blink()
{
   unsigned int k;
    for (k = 0; k < 1200; k++);
}

#include<reg51.h>    //header file

#define  LED1_ON   1
#define  LED1_OFF  0
#define  LED2_ON   1
#define  LED2_OFF  0
#define  LED3_ON   1
#define  LED4_OFF  0

sbit   LED1     = P2^0;    //LED 1 conncted to port P2 pin 0
sbit   LED2     = P2^1;    //LED 2 conncted to port P2 pin 1
sbit   LED3     = P2^2;    //LED 3 conncted to port P2 pin 2

typedef enum
{
    task1,
    task2,
    task3
};
// prototype function
void LED1_Blink(void);
void LED2_Blink(void);
void LED3_Blink(void);
int main(void)
{
   unsigned int task=0;

    while(1)
  {
   switch  (task)
   {
      case task1:
                 if (task == task1)
                 {
                    LED1 = LED1_ON;
                    LED1_Blink();
                    LED1 = LED1_OFF;
                 }
         break;

      case task2:
                 if (task == task2)
                 {
                      LED2 = LED2_ON;
                      LED2_Blink();
                      LED2 = LED2_OFF;
                 }
         break;

      case task3:
                 if (task == task3)
                 {
                    LED3 = LED3_ON;
                    LED3_Blink();
                    LED3 = LED4_OFF;
                 }
         break;
   }
if(++task > 2) task = 0;
}
}

void LED1_Blink ()
{
    unsigned int i;
    for (i = 0; i < 1000; i++);
}

void LED2_Blink()
{
    unsigned int j;
    for (j = 0; j < 1500; j++);
}

void LED3_Blink()
{
   unsigned int k;
    for (k = 0; k < 1200; k++);
}