My streams are not parallel, they are serial. How to make them parallel?

Question

I practice multithreading.

I create two posix streams that display text on the screen (an endless loop), but it only seems to be the first time the stream starts. I change the program without a loop, first prints the threads, the next - the second thread. It seems that my thread is not parallel, the first thread should end before the start of the second recording. How can I make them parallel?

Thank,

hdr.h

#ifndef HDR_HDR_H_
#define HDR_HDR_H_
#define HDR_HDR_H_
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#endif /* HDR_HDR_H_ */

multithread01.c

#include "../hdr/myfunc.h"
pthread_mutex_t lock;

int main(int argc, char **argv)
{
    pthread_t tid01;
    pthread_t tid02;
    void * status01;
    void * status02;

    pthread_create(&tid01, NULL, PrintOut01(), NULL);
    pthread_create(&tid02, NULL, PrintOut02(), NULL);

    pthread_join(&tid01, &status01);
    pthread_join(&tid02, &status02);

    return 0;

}

myfunc.h

#ifndef HDR_MYFUNC_H_
#define HDR_MYFUNC_H_
#include "../hdr/hdr.h"
void * PrintOut01 (void);
void * PrintOut02 (void);
#endif /* HDR_MYFUNC_H_ */

myfunc.c

#include "../hdr/hdr.h"

extern pthread_mutex_t lock;

void * PrintOut01 ()
{
    while (1)
    {
        pthread_mutex_lock(&lock);
        printf ("This is thread 01\n");
        pthread_mutex_unlock(&lock);
    }
}

void * PrintOut02 ()
{
    while (1)
    {
        pthread_mutex_lock(&lock);
        printf ("This is thread 02\n");
        pthread_mutex_unlock(&lock);
    }
}

Answer 1

This is because you are calling functions in your call pthread_create, you are not passing pointers to functions.

Compare wrong

pthread_create(&tid01, NULL, PrintOut01(), NULL);

with the right

pthread_create(&tid01, NULL, PrintOut01, NULL);

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