/***************************************************************
  File:          red_barrier.h
  Description:   A program that implements a barrier using a
                 conditional variable from the pthread library. 
                                                         
  Author:        Dana Vrajitoru                          
  Organization:  IUSB, Computer and Information Sciences
  Date:          September 2020
****************************************************************/

#ifndef RED_BARRIER_H
#define RED_BARRIER_H

// Creates the threads calling the Ship_check_in function.
void Create_threads(pthread_t *threads, int no_threads);

// Joins all of the threads so that the program doesn;t end before
// they have finished the work.
void Synchronise(pthread_t *threads, int no_threads);

// Inputs the number of ships and initializes the global variables.
void Init_data(int &no_threads);

// A barrier function based on the number of threads implemented using
// a conditional variable. It uses a global counter intialized as
// 0. Each thread coming in increments the counter. If the count is
// not equal to the number of threads, it goes into a wait on the
// conditional variable. The thread that finds the counter equal to
// the number of threads broadcasts the condition that releases all of
// them.
void Barrier(int no_threads) ;

// The thread function: gets an id number, prints a message, calls the
// barrier, prints a second message. The purpose is to see if the
// messages printed by all the threads before the barrier are
// separated from the one printed by the threads after the barrier.
void *Ship_check_in(void *arg) ;

// Copies the value of a global id into the reference parameter and
// increments the global id.
void Get_id(int &id);

// Waits for a given delay specified in miliseconds.
void Wait(int miliseconds);

#endif