在C中创建线程(Threads creation in C)

void print_hello_world() {
    pid_t pid = getpid();
    printf("Hello world %d\n", pid);
    pthread_exit(0);
}

void main() {
    pthread_t thread;
    pthread_create(&thread, NULL, (void *) &print_hello_world, NULL);
    print_hello_world();
}
 
 我真的不明白pthread_create中的（void *）需要什么。 我们是否需要“＆print_hello_world”或者可以放下“＆”，因为我已经在某处传递函数指针，而我们不需要在函数名称前放置“＆”。 

void print_hello_world() {
    pid_t pid = getpid();
    printf("Hello world %d\n", pid);
    pthread_exit(0);
}

void main() {
    pthread_t thread;
    pthread_create(&thread, NULL, (void *) &print_hello_world, NULL);
    print_hello_world();
}
 
I really couldn't understand what is the need of (void *) in pthread_create. And do we need "&print_hello_world" in the same or could drop "&" as I have read somewhere that while passing function pointers we don't need to place "&" before the function name.

原文：https://stackoverflow.com/questions/31810161