MapleCoOS library for Maple platform to implement realtime CoOS.
Also need change systick.c and systick.h in hardware\leaflabs\cores\maple folder
Blink example
 

#include <MapleCoOS.h>
/*
    Blink
 
    Turns on an LED on for one second, then off for one second, repeatedly.
 
    * LED connected from digital pin 13 to ground.
*/

int ledPin =  13;    // LED connected to digital pin 13

#define LCD_BLINK_PRI    3    /* Priority of 'lcd_blink' task. */
#define UART_PRINT_PRI   4    /* Priority of 'tart_print' task. */

OS_STK   task_init_Stack[TASK_STK_SIZE]; 	  /* Stack of 'task_init' task. */
OS_STK   led_display_Stack[TASK_STK_SIZE];	  /* Stack of 'led_display' task. */
OS_STK   uart_print_Stack[TASK_STK_SIZE];	  /* Stack of 'uart_print' task. */

OS_MutexID mut_uart;    /* Save id of mutex. */

byte char_uart = 0;

//
//    This task use to blink led.
//
void led_blink(void *pdata)
{
    char i;
    for (;;)
    {
        for (i = 0; i < 19; i++)
        {
            digitalWrite(ledPin, !digitalRead(ledPin));   // toggle the LED
	    CoTickDelay (1000);
	}
    }
}

//
//    This task print value by UART.
//
void uart_print(void *pdata)
{
    for (;;)
    {
        CoEnterMutexSection(mut_uart);		/* Enter mutex area. */

        SerialUSB.write('.');

        CoLeaveMutexSection(mut_uart); 		/* Leave mutex area. */

        CoTickDelay(1000);
    }
}

//
//    This task is called to initial hardware and created tasks.
//
void task_init(void *pdata)
{
    CoCreateTask(led_blink, (void *)0, LCD_BLINK_PRI, &led_display_Stack[TASK_STK_SIZE - 1], TASK_STK_SIZE );
    CoCreateTask(uart_print, (void *)0, UART_PRINT_PRI, &uart_print_Stack[TASK_STK_SIZE - 1], TASK_STK_SIZE );
    CoExitTask();    /*!< Delete 'task_init' task. */
}

// The setup() method runs once, when the sketch starts
void setup()   {
    // initialize the digital pin as an output:
    pinMode(ledPin, OUTPUT);

    CoInitOS();
    CoCreateTask(task_init, (void *)0, 10, &task_init_Stack[TASK_STK_SIZE-1], TASK_STK_SIZE);
    CoStartOS ();
}

// the loop() method runs over and over again
void loop()
{
}