/*
 *  Distributed system implementation using IPC.
 */

#ifndef DS_H
#define DS_H

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>

#define N 5

#define QUEUE_KEY_PREFIX 256
#define DS_MESSAGE_TYPE 1

/* Get N communication queues */
void get_queues();  

/* Send a message to Pj. */
void send_message(int j, const void* buffer, size_t msgsize);
/* Broadcast a message to all processes, including itself. */
void broadcast(const void* buffer, size_t msgsize);
  
/* Wait for a new message */ 
void receive_message(int pid, void* buffer, size_t msgsize);
/* Returns -1 immediately if no message is available in the queue. 
   Returns 0 and a new message in buffer otherwise. */
int nowait_receive_message(int pid, void* buffer, size_t msgsize);

#endif