testfunc
extern int testfunc(void);
printf("%d\n", testfunc());
void (*testfunc)(void) = arg;
testfunc();
void (*testfunc)(void);
testfunc = dlsym(dso, "testfunc");
if (testfunc == NULL)
if (pthread_create(&thread, NULL, thread_helper, testfunc))
int testfunc(void);