solucao_Teste2016.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/errno.h>

#define N_NEWSTEAMS 10
#define EXAMPLE_NEWS 5
#define NEWS_MAX_SIZE 512

int main_pid;
int pipes [N_NEWSTEAMS][2];
fd_set read_set;

// Just some news used as an example

char example_news[EXAMPLE_NEWS][NEWS_MAX_SIZE] = {
"all about the money",
"food for the soul",
"home team wins",
"an amazing discovery",
"newest tec came out"
};

// News structure that will be used to send news through the pipes
typedef struct _news {
  int team;
  char newsText[NEWS_MAX_SIZE];
} news;

news news_data;

//Treatment of signal generated by Ctrl+C
//Editor waits for all the NEWSTEAMS to finish and removes resources (closes all open
//pipes); NEWSTEAMS clean used resources (close all open pipes). Each process prints a
//message to the screen (see example output)

void sigint(int signum) {
  /*COMPLETE*/
  printf("^C pressed. Shutting down news team [%d]\n", getpid());
  for(int i=0;i<N_NEWSTEAMS; i++){
    close(pipes[i][0]);
    close(pipes[i][1]);
    wait(NULL);
  }
  /*END COMPLETE*/
  exit(0);
}

// Code run by NEWSTEAMS
void newsTeam(int channel[], int i){
  news_data.team = i;
  srand(i);
  // *** COMPLETE: Handle CTRL-C ***
  signal(SIGINT, sigint);

  // *** END COMPLETE ***
  while(1){
    //pick a random news content
    strcpy(news_data.newsText , example_news[rand() % EXAMPLE_NEWS]);
    printf("News team %d Submitting news: \"%s\" \n", news_data.team,news_data.newsText);
    /*COMPLETE Send news to pipe and sleep between 1 to 3 seconds */
    close(channel[0]);
    write(channel[1], &news_data, sizeof(news_data));
    sleep(rand()%4+1);
    /*END COMPLETE*/
  }
}

// Main
int main() {
  main_pid = getpid();
  // *** COMPLETE: Ignore CTRL-C ***
  signal(SIGINT, SIG_IGN);

  // *** END COMPLETE ***

  // *** COMPLETE: Create NEWSTEAMS (processes and pipes) ***
  for(int i=0; i<N_NEWSTEAMS; i++){
    pipe(pipes[i]);
  }

  for(int i=0; i<N_NEWSTEAMS; i++){
    if(fork()==0){
      newsTeam(pipes[i], i);
      exit(0);
    }
  }

  usleep(10);

  // *** END COMPLETE ***
  // Editor
  fd_set read_set;
  int received=0;
  // *** COMPLETE: Handle CTRL-C***
  signal(SIGINT, sigint);
  // *** END COMPLETE ***

  printf("Listening to pipes\n");

  while (1) {
    // *** COMPLETE: Read from Pipes, publish only 10% ***
    FD_ZERO(&read_set);
    for(int i=0; i<N_NEWSTEAMS; i++){
      FD_SET(pipes[i][0], &read_set);
    }
    if(select(pipes[N_NEWSTEAMS-1][0]+1, &read_set, NULL, NULL, NULL) > 0){
      for(int i=0; i<N_NEWSTEAMS; i++){
        if(FD_ISSET(pipes[i][0], &read_set)){
          news new;
          read(pipes[i][0], &new, sizeof(new));
          received++;
          if(received >=10){
            printf("NEWS FLASH: team[%d]: %s\n", new.team, new.newsText);
            fflush(stdout);
            received = 0;
          }
        }
      }
    }
    // *** END COMPLETE ***

  } // While(1)
return 0;
}