lock/unlock and syscall(224)

gistfile1.txt

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

// or syscall(224)
#define gettid() syscall(__NR_gettid)

void* thread(void* args)
{
    int tid = syscall(224);
    int* ptr = (int*)((void**)args)[1];
    printf("%d %d\n", tid, *ptr);

    pthread_mutex_t mutex = *((pthread_mutex_t*)args);
    pthread_mutex_lock(&mutex);
    ++(*ptr);
    pthread_mutex_unlock(&mutex);
    printf("%d %d\n", tid, (*ptr));

    return NULL;
}

int main(int argc, char* argv[]) {
    pthread_t thread1;
    pthread_t thread2;

    pthread_mutex_t mutex;
    pthread_mutex_init(&mutex, NULL);

    int a = 1;
    void* args[2] = {(void*)&mutex, (void*)&a};
    printf("%d\n", *(int *)args[1]);

    pthread_create(&thread1, NULL, thread, args);
    pthread_create(&thread2, NULL, thread, args);
    printf("\n");

    sleep(10);
}