hickman (01/10/83)
#R:we13:-35900:zinfandel:12400008:000:706 zinfandel!hickman Jan 8 16:14:00 1983 You clearly do not understand the real problem behind locking. Access is fine, in that it will correctly tell any program if a file exists or not. But using access and then using creat is not a single operation, but two, which means the locking can fail. If for example, two process's were running simultaneously down the same piece of code, they both would get the correct information from access(), and both of them would then, in their opinion, correctly, perform a creat(). Thus, for proper locking to be done, it must be done through a system call which is "atomic". creat() is atomic, so is link(). creat() won't work for root, but link() will..... Hope this helped some... kipp hickman