// test TRT with two tasks and one mutex:
// Task 1  reads the buttons (PORTB), 
//         and blinks an LED if it owns the mutex
// Task 2  reads the buttons (PORTB), 
//         and blinks an LED if it owns the mutex

#include "trtSettings.h"
#include "trtkernel644.c"
#include "trtMutex.c"
#include <stdio.h>
#include <avr/sleep.h>

// serial communication library
// Don't mess with the semaphores
#define SEM_RX_ISR_SIGNAL 1
#define SEM_STRING_DONE 2 // user hit <enter>
#include "trtUart.h"
#include "trtUart.c"
// UART file descriptor
// putchar and getchar are in uart.c
FILE uart_str = FDEV_SETUP_STREAM(uart_putchar, uart_getchar, _FDEV_SETUP_RW);

// semaphore to protect shared variable
#define SEM_MUTEX 3

// the usual
#define begin {
#define end }

// --- control LEDs from buttons and uart -------------------
// input arguments to each thread
// not actually used in this example
int args[2] ;

// shared led status
uint8_t led ;

// --- define task 1  ----------------------------------------
void mutex1(void* args) 
  begin	
  	uint32_t rel, dead ;
	uint8_t sw ;

	while(1)
	begin
		// read the buttons
		// if  button 7 is pushed grab the mutex
		// if  button 6 is pushed drop the mutex
		sw = ~PINB ;
		if (sw & (1<<PINB7))
			trtLockMutex(SEM_MUTEX);

		if (sw & (1<<PINB6))
			trtUnlockMutex(SEM_MUTEX);

		// blink if owned
		if (trtOwnerMutex(SEM_MUTEX)){
			led = led ^ (1<<7) ;
			PORTC = ~led ;
		}

		// Sleep
	    rel = trtCurrentTime() + SECONDS2TICKS(0.1);
	    dead = trtCurrentTime() + SECONDS2TICKS(0.1);
	    trtSleepUntil(rel, dead);
	end
  end

// --- define task 2  ----------------------------------------
void mutex2(void* args) 
  begin
  	uint32_t rel, dead ;
	uint8_t sw ;
	while(1)
	begin
		// read the buttons
		// if  button 0 is pushed grab the mutex
		// if  button 1 is pushed drop the mutex
		sw = ~PINB ;
		if (sw & (1<<PINB0))
			trtLockMutex(SEM_MUTEX);

		if (sw & (1<<PINB1))
			trtUnlockMutex(SEM_MUTEX);
		
		// blink if owned
		if (trtOwnerMutex(SEM_MUTEX)){
			led = led ^ (1<<0) ;
			PORTC = ~led ;
		}

		// Sleep
	    rel = trtCurrentTime() + SECONDS2TICKS(0.1);
	    dead = trtCurrentTime() + SECONDS2TICKS(0.1);
	    trtSleepUntil(rel, dead);

	end
  end

// --- Main Program ----------------------------------
int main(void) {

  DDRC = 0xff;    // led connections
  PORTC = 0xff;

  //init the UART -- trt_uart_init() is in trtUart.c
  trt_uart_init();
  stdout = stdin = stderr = &uart_str;
  fprintf(stdout,"\n\r TRT 9feb2009\n\r\n\r");

  // start TRT
  trtInitKernel(80); // 80 bytes for the idle task stack

  // init mutex 
  trtInitMutex();

  // --- create semaphores ----------
  // You must creat the first two semaphores if you use the uart
  trtCreateSemaphore(SEM_RX_ISR_SIGNAL, 0) ; // uart receive ISR semaphore
  trtCreateSemaphore(SEM_STRING_DONE,0) ;  // user typed <enter>
  
  // resource protection
  trtCreateMutex(SEM_MUTEX) ; // protect shared LEDs

 // --- creat tasks  ----------------
  trtCreateTask(mutex1, 100, SECONDS2TICKS(0.1), SECONDS2TICKS(0.1), &(args[0]));
  trtCreateTask(mutex2, 100, SECONDS2TICKS(0.1), SECONDS2TICKS(0.1), &(args[1]));
  
  // --- Idle task --------------------------------------
  // sleeps the cpu to save power 
  // every time it executes
  set_sleep_mode(SLEEP_MODE_IDLE);
  sleep_enable();
  while (1) 
  begin
  	sleep_cpu();
  end

} // main