2 producer 1 consumer // Running here: http://ideone.com/N83BRQ

2producer1consumer.cpp

#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
#include <math.h>
#include <ctype.h>

#define NUM   15
int number = NUM, buff = 0;
char queue[NUM][NUM];
sem_t full_sem, empty_sem;


void insert(char e[]) {
    if (buff + 1 < number) {
        buff++;
        printf(", inserted text: %s", e);
        int i = 0;
        for (i = 0; i < number; ++i) {
            queue[buff][i] = e[i];
        }
    } else {
        printf("\nfull");
    }
}


void *produce2() {
    int i = 0;
        sem_wait(&full_sem);
        printf("\nP2::  insert random text #%d", i);
        char tmpChar[number];
        int j = 0;
        for (j = 0; j < number; ++j) {
            tmpChar[j] = (char) 'a' + (random() % 26);
        }
        insert(tmpChar);
        sem_post(&empty_sem);
    


}

void *produce() {
    int i = 0;
        sem_wait(&full_sem);
        printf("\nP1:: insert random text #%d", i);
        char tmpChar[number];
        int j = 0;
        for (j = 0; j < number; ++j) {
            tmpChar[j] = (char) 'a' + (random() % 26);
        }
        insert(tmpChar);
        sem_post(&empty_sem);
    


}

void *consume(void *a) {

    int i = 0;
        char v[number];
        sem_wait(&empty_sem);

        if (buff > 0) {
            int j = 0;
            for (j = 0; j < number; ++j) {
                v[j] = toupper(queue[buff][j]);
            }
            buff--;
        } else {
            printf("\nempty");
        }

        printf("\nuppercase char: %s", v);
        sem_post(&full_sem);
    


}

int main() {
    pthread_t t[3];
    sem_init(&full_sem, 0, number - 1);
    sem_init(&empty_sem, 0, 0);

    pthread_create(&t[0], NULL, &produce, NULL);
    pthread_create(&t[1], NULL, &produce2, NULL);

    pthread_create(&t[2], NULL, &consume, NULL);
    pthread_create(&t[2], NULL, &consume, NULL);

    pthread_join(t[0], NULL);
    pthread_join(t[1], NULL);
    pthread_join(t[2], NULL);

    sem_destroy(&full_sem);
    sem_destroy(&empty_sem);
    return 0;
}

|SampleOutput

// output from : http://ideone.com/N83BRQ
P2::  insert random text #0, inserted text: nwlrbbmqbhcdarz
uppercase char: NWLRBBMQBHCDARZ
P1:: insert random text #0, inserted text: owkkyhiddqscdxr
uppercase char: OWKKYHIDDQSCDXR