Different behaviors between Linux and Windows using threads(pthreads)

Question

I’m using the Linux pthreads library to try out the functionality of threads, the code below prints 5 messages on the screen for each thread, each thread waits its turn to display the message controlled using the semaphores, on Windows works perfectly, but in linux threads do not wait their turn, I already researched everything that is singing and could not find a solution to this problem.

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

typedef struct param{
  int id;
  pthread_mutex_t lock;
  sem_t semaforo;
}valores_t;

void * olamundo(void* args){
  valores_t* p = args;
  sem_post(&p->semaforo);
  for (size_t i = 0; i < 5; i++) {
    printf("Ola mundo da thread %d\n", p->id);
  }
  sem_wait(&p->semaforo);
}

sem_t semaforo;

int main(int argc, char const *argv[]) {
  /* code */

  if(sem_init(&semaforo,0,1)){//valor inicial do semaforo começa por 1
    printf("Erro ao iniciar o semaforo\n");
  }

  valores_t p[2];
  pthread_t threads[2];

    p[0].id = 1;
    p[0].semaforo = semaforo;

    p[1].id = 2;
    p[1].semaforo = semaforo;

  for(int i = 0; i < 2; i++){//inicia as funcoes das threads
    if(pthread_create(&(threads[i]), NULL, &olamundo, &p[i]) == -1){
      printf("Erro ao inicializar a thread\n");
    }
  }

  for(int i = 0; i < 2; i++){
        if(pthread_join(threads[i], NULL)){
      printf("Erro ao sincronizar a thread\n");
    }
    }
    sem_destroy (&semaforo);
  return 0;
}

Answer 1

It turns out that it is a bug in the compiler, to solve this problem to work on both platforms use a pointer in struct, for more details on the solution see this other thread in stackoverflow threads

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

typedef struct param{
    int id;
    pthread_mutex_t lock;
    sem_t *semaforo; //Dagan: change to a pointer to a semaphore
}valores_t;

void * olamundo(void* args){
    valores_t* p = args;
    sem_wait(*(&p->semaforo)); //Dagan: use the semaphore pointer
    for (size_t i = 0; i < 25; i++) {
        printf("Ola mundo da thread %d\n", p->id);
    }
    sem_post(*(&p->semaforo)); //Dagan: use the semaphore pointer
}

sem_t semaforo;

int main(int argc, char const *argv[]) {
    /* code */

    if(sem_init(&semaforo,0,1)){//valor inicial do semaforo começa por 1
        printf("Erro ao iniciar o semaforo\n");
    }

    valores_t p[2];
    pthread_t threads[2];

    p[0].id = 1;
    p[0].semaforo = &semaforo; //Dagan: pass the address of the semaphore

    p[1].id = 2;
    p[1].semaforo = &semaforo; //Dagan: pass the address of the semaphore

    for(int i = 0; i < 2; i++){//inicia as funcoes das threads
        if(pthread_create(&(threads[i]), NULL, &olamundo, &p[i]) == -1){
            printf("Erro ao inicializar a thread\n");
        }
    }

    for(int i = 0; i < 2; i++){
        if(pthread_join(threads[i], NULL)){
            printf("Erro ao sincronizar a thread\n");
        }
    }
    sem_destroy (&semaforo);
    return 0;
}