purpose of FileDispatcher.preClose()

[Alan Bateman]

Michael Allman wrote:
> :
>
> I think the problem here is that FileChannelImpl.implCloseChannel() 
> calls nd.preClose(fd) before the block that releases its file locks.  
> On non-windows, nd.preClose(fd) doesn't just "pre close" fd, it closes 
> it. Then implCloseChannel() tries to release its file locks.  fd now 
> points to a socket descriptor and on Solaris/Linux, such attempt seems 
> to be harmless.  On Mac OS X, it complains with the EBADF error code.
Yes, this is a known issue but hasn't been a problem to date. I don't 
know Mac OS X well but if closing a file causes all advisory locks on 
the file to be removed then the simplest solution for your port is 
probably to just comment out the call to release0 that is called from 
the inner class in implCloseChannel. As you've found this will otherwise 
attempt the unlock on the dup'ed file descriptor and fail.

-Alan.