pingpong3.cpp

//Brian McBride
//Ping Pong application
//9/15/08
#include <pthread.h>
#include <iostream>
#include <string>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>




int displayType = 0;
int pairs = 0;


pthread_cond_t conditionPing = PTHREAD_COND_INITIALIZER;
pthread_cond_t conditionPong = PTHREAD_COND_INITIALIZER;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;



void *ping ( void *){
  int i;
  for( i = 1; i <= pairs; i++){
    pthread_mutex_lock( &mutex );
    while( displayType != 0 )
      pthread_cond_wait( &conditionPing, &mutex);
    displayType = 1;
    std::cout<< i << ".) Ping\n";
    pthread_cond_signal( &conditionPong );
    pthread_mutex_unlock( &mutex );
  }
  pthread_exit(0);
}
 
void *pong ( void *){
  int i;
  for( i = 1; i <= pairs; i++){
    pthread_mutex_lock( &mutex );
    while( displayType != 1 )
      pthread_cond_wait( &conditionPong, &mutex);
    displayType = 0;
    if( i < 10 ){
      std::cout<<"    Pong\n\n";
    }else
      std::cout<<"     Pong\n\n";
    pthread_cond_signal( &conditionPing );
    pthread_mutex_unlock( &mutex );
  }
  pthread_exit(0);
}
   
int main(int argc, char * argv[]){
  pairs = atoi(argv[1]);
  pthread_t tID[2];
  pthread_create( tID, NULL, ping, NULL);
  pthread_create( tID + 1, NULL, pong, NULL);
  pthread_exit( NULL );
}