process_3.c

#include "process_3.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "constants.h"
#include <signal.h>
#include <semaphore.h>
#include <fcntl.h>
#include <sys/mman.h>

extern SharedData *shmPtr;

static void SetupSignals()
{
    sigset_t signals;
    sigfillset(&signals);
    sigprocmask(SIG_BLOCK, &signals, NULL);
}

void process3(int pipe_p2_write, int pipe_p1_read, sem_t *sem_parent_to_p3, sem_t *sem_p3_to_p2, int shmId)
{

    SetupSignals();
    shmPtr = mmap(0, sizeof(SharedData), PROT_WRITE | PROT_READ, MAP_SHARED, shmId, 0);
    if (!shmPtr)
    {
        printf("Failed to create shmPtr\n");
        exit(1);
    }

    int choice;
    int shouldSkip = 0;
    while (1)
    {
        if (!shouldSkip)
        {
            scanf("%d", &choice);
            while (getchar() != '\n');
            if (choice == 1)
            {
                fflush(stdout);
                char buf[MAX_TEXT_SIZE];
                fgets(buf, MAX_TEXT_SIZE, stdin);
                if (write(pipe_p2_write, buf, strlen(buf)) < 0)
                {
                    printf("Failed to write data using pipe to p2\n");
                    exit(1);
                }
                printf("P3(%d): Sent data via pipe to p2\n", getpid());
                fflush(stdout);
            }
            else if (choice == 2)
            {
                FILE *file = fopen("input.txt", "r");
                if (!file)
                {
                    printf("Failed to open input.txt\n");
                    exit(1);
                }
                char buf[MAX_TEXT_SIZE];
                while (fgets(buf, MAX_TEXT_SIZE, file))
                {
                    int len = strlen(buf);
                    if (write(pipe_p2_write, buf, len + 1) < 0)
                    {
                        printf("Failed to write data using pipe to p2\n");
                        fclose(file);
                        exit(1);
                    }
                    printf("P3(%d): Sent data via pipe to p2\n", getpid());
                    fflush(stdout);
                }
                fclose(file);
            }
            else
            {
                printf("Invalid choice. Enter 1 or 2.\n");
            }
        }

        if (sem_trywait(sem_parent_to_p3) == 0)
        {
            sem_post(sem_p3_to_p2);
            if (shmPtr->signum == SIGTERM)
            {
                printf("P3(%i): received signal %i\n", getpid(), shmPtr->signum);
                break;
            }
            else if (shmPtr->signum == SIGTSTP)
            {
                shouldSkip = 1;
            }
            else if (shmPtr->signum == SIGCONT)
            {
                shouldSkip = 0;
            }
        }
    }
}