#include <pthread.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
void *volatile mem;
volatile int len;
void *Thread(void *p) {
while ((p = __atomic_load_n(&mem, __ATOMIC_ACQUIRE)) == 0)
usleep(100);
memset(p, 0, len);
return 0;
}
extern "C" void libfunc() {
pthread_t t;
pthread_create(&t, 0, Thread, 0);
len = 10;
__atomic_store_n(&mem, malloc(len), __ATOMIC_RELEASE);
pthread_join(t, 0);
free(mem);
fprintf(stderr, "OK\n");
}