Linux 3.5：从多个线程安全地从同一个fd`open（2）``/ dev / urandom`中读取（2）`

Is it safe to do this:

这样做是否安全:

int fd;

void thread_main()
{
    char buf[M];
    ssize_t r = read(fd, buf, M);
    assert(r == M);
    ...
}

int main()
{
    fd = open("/dev/urandom", O_RDONLY);

    for (int i = 0; i < N; i++)
         start_thread(i);

    for (int i = 0; i < N; i++)
         join_thread(i);
}
int fd;

vo