On 7/10/19 5:17 PM, Brian Burkhalter wrote:
I incorporated Peter’s version, adding the security check in
cancelDeleteOnExit(), tweaking its verbiage along with that of deleteOnExit(),
and modified the test DeleteOnExit to verify the new method. The updated
version is here:
http://cr.openjdk.java.net/~bpb/8193072/webrev.03/
<http://cr.openjdk.java.net/~bpb/8193072/webrev.03/>
There is possibility of a race here in a scenario like this:
File dir = new File("dir");
File file = new File("dir/file");
-- thread 1 --
dir.deleteOnExit();
file.deleteOnExit();
///
dir.cancelDeleteOnExit();
//// thread 2 intervenes
file.cancelDeleteOnExit();
-- end --
-- thread 2 --
dir.deleteOnExit();
file.deleteOnExit();
-- end --
The result will be that the order of the registered files will change,
and JVM will try to delete dir first (this will fail as it is not empty).
Of course it could be avoided, if cancellation were done in reverse
order, though it's not immediately obvious from the documentation.
With kind regards,
Ivan
Thanks,
Brian
On Jul 10, 2019, at 11:17 AM, Brian Burkhalter <brian.burkhal...@oracle.com>
wrote:
On Jul 10, 2019, at 5:36 AM, Peter Levart <peter.lev...@gmail.com> wrote:
There are various interleavings of threads that could cause the file to be left
undeleted when VM exits.
To cover concurrent scenarios such as above, the code could use reference
counting. Like in the following patch:
http://cr.openjdk.java.net/~plevart/jdk-dev/8193072_File.undoDeleteOnExit/webrev.01/
<http://cr.openjdk.java.net/~plevart/jdk-dev/8193072_File.undoDeleteOnExit/webrev.01/>
This looks good to me modulo adding this
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkDelete(path);
}
to cancelDeleteOnExit() as suggested below.
On Jul 10, 2019, at 7:51 AM, Sean Mullan <sean.mul...@oracle.com> wrote:
On 7/9/19 7:40 PM, Brian Burkhalter wrote:
I don’t know. On the one hand this does not take an action like reading,
writing, or deleting, but on the other it could end up causing files to be left
lying around after VM termination which were expected to be deleted. I suppose
that could be considered to be some sort of security issue.
Yes I think so.
I would probably just use the same permission (FilePermission(file,"delete")).
If you have been granted permission to delete a file, then you should have permission to
cancel that deletion as well.
That’s a good idea.
--
With kind regards,
Ivan Gerasimov
