C ++线程-pthread_create，pthread_join

Question

Can you tell me what I am doing wrong here? I am implementing pthread_create incorrectly

int iret1 = pthread_create(&producer, NULL, produce, void*);

int iret2 = pthread_create(&consumer1, NULL, consume, void*);

#include <iostream>
#include <cstdlib>
#include <pthread.h>
#include <ctime>
#include <time.h>

#define EMPTY 0
#define FILLED 1
#define BUFFER_SIZE 20

using namespace std;

//prototypes
void produce();
void consume(int);

int buffer[BUFFER_SIZE];

int main()
{


    int iret1 = pthread_create(&producer, NULL, produce, NULL);

    //join the threads



    return 0;
}

Answer 1

If you are not using thread routine argument, just pass NULL pointer instead of void* :

pthread_create( &producer, NULL, produce, NULL );

The thread routine is supposed to be of void* ()( void* ) type. Yours are different. It should be something like:

/// My fancy producer thread routine
extern "C" void* produce( void* arg ) {

    // do your thing here

    return 0; // or something if you want the result in pthread_join
}

Also, sleep(3) is not the greatest way of thread synchronization :)

Answer 2

Pass NULL as the fourth parameters, not void * (that's just its type).

Also, the type of the thread functions should be

void * produce(void *)
{...}

The are functions returning a void pointer and taking a parameter of a void pointer.