RFR: 6244047: impossible to specify directories to logging FileHandler unless they exist
jim.gish at oracle.com
Tue Nov 13 21:30:18 UTC 2012
Here's a new webrev with my latest changes for your reviewing pleasure :-)
- Using the file channel directly as suggested.
- Instead of checking up front for a valid directory I check the
IOException on the channel open and process it accordingly. (BTW, I much
prefer my previous proposed fix because I like to ensure pre-conditions
for an operation are met prior to it rather than attempting the op,
failing, and then recovering),
- Eliminated the stream, which really isn't needed, and just use the
Just for the purposes of my enlightenment, assuming this is what you
were after (Jason & Alan), what was your issue with checking for a valid
On 11/13/2012 03:52 PM, Jim Gish wrote:
> On 11/13/2012 03:36 PM, Jason Mehrens wrote:
>> Looking at the webrev again I think I tricked myself into thinking
>> that 'parentFile' was a file that could be opened with a stream when
>> it actually is a directory. I think the best fix would be to add a
>> check in the catch block (around line 432) and only continue if the
>> directory of the generated file
>> java.nio.file.Files.isWritable/isDirectory otherwise throw the
>> original exception.
> I have a variant, which I think may do the trick which I'll post
> shortly. The catch block on 432 is for when the tryLock fails. I
> think it's best to check the IOException around 420.
>> If the running JVM terminates abnormally won't the lock file fail to
>> be deleted? On restart, the lock file will exist to protect a dead
> Yes, except that you can't really distinguish between that and another
> JVM using the lock file. It's safer just to grab another file --
> which is what the logic is already setup to do.
>> Date: Tue, 13 Nov 2012 13:25:27 -0500
>> From: jim.gish at oracle.com
>> To: Alan.Bateman at oracle.com
>> CC: jason_mehrens at hotmail.com; core-libs-dev at openjdk.java.net
>> Subject: Re: RFR: 6244047: impossible to specify directories to
>> logging FileHandler unless they exist
>> On 11/13/2012 07:08 AM, Alan Bateman wrote:
>> On 12/11/2012 23:22, Jim Gish wrote:
>> Which file(s) are you concerned about truncating/damaging?
>> The code I'm impacting is for creating a new lock file. Where
>> is the potential for truncating/damaging that you both are
>> referring to?
>> Is this sufficient (plus the proper exception handling of
>> course) ?
>> //lockStream = new
>> fc = FileChannel.open(new
>> File(lockFileName).toPath(), CREATE_NEW, WRITE);
>> //fc = lockStream.getChannel();
>> CREATE rather than CREATE_NEW so that it doesn't fail if the lock
>> file already exists. Although it's just a lock file then I think
>> it would be impolite to truncate it.
>> You could use Paths.get(lockFileName)rather than new
>> File(lockFileName).toPath() here but either is fine.
>> I think we want it to fail if the lock file already exists. That's
>> why I used CREATE_NEW. At least the way the logic is now, is that it
>> attempts to create a new file and if it fails it tries again until it
>> can create a new one. It may be the case that the lockFileName is
>> not in the locks map, and thus we don't own it, but it's possible
>> that another JVM/app is logging in the same location. It, of course,
>> would be bad practice, but not disallowed. We shouldn't be grabbing
>> a lock file that might otherwise be in use.
>> Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304
>> Oracle Java Platform Group | Core Libraries Team
>> 35 Network Drive
>> Burlington, MA 01803
>> jim.gish at oracle.com <mailto:jim.gish at oracle.com>
Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304
Oracle Java Platform Group | Core Libraries Team
35 Network Drive
Burlington, MA 01803
jim.gish at oracle.com
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