Hi -
Turns out my analysis was a red herring - the InvalidDirectoryError I received was actually a genuine problem which caused the whole computation to abort before it even reached the updating part. I got confused because I didn't realize that the problem might be caused before it ever gets to the updating part and invoking the updater manually would of course work.
Apologies for making a fuzz over nothing.
Cheers, - Andreas
Andreas Raab wrote:
J J wrote:
What kind of filesystem is this on? Are you accessing the directory via NFS or any other indirect means? What kind of modifications are happening to the directory?
It's an ext3 file system locally mounted. The modifications consist of adding and removing both files and directories.
I have not seen this in Squeak, but it reminds me of what happens when something causes an inode change underneath a running process.
Right, I've seen that too. But if you look at the FileDirectory code you'll notice that the only thing it uses is a fully qualified path; it does not have any internal state other than that. Because of this, the VM ought to check every time you are querying, or if it caches it ought to know when to recheck (most definitely upon failure).
Cheers,
- Andreas
Example:
On a unix/linux box you cd to /some/place/nice. Then on another shell you cd to /some/place and rm -rf nice. Then copy a new "nice" directory from somewhere else, so that the directory structure is as it was before. Now you go back to the original shell and ls, but you get the error ". no such file or directory" or something similar. Clearly the directory does exist, but the problem is your shell is still referencing the previous inodes that are no longer valid. And I have even seen certain backup systems cause this.
So in your case, maybe the VM or your code is holding a reference to the directory some how and another process is causing an inode change in some way, which causes the error. When you run it in the debugger, it bypasses the cache somehow causing it to work again.
Just a wild guess, but that's all I can think of.
Hope it helps, Jason
From: Andreas Raab andreas.raab@gmx.de Reply-To: The general-purpose Squeak developers listsqueak-dev@lists.squeakfoundation.org To: The general-purpose Squeak developers listsqueak-dev@lists.squeakfoundation.org, Squeak Virtual Machine Development Discussionvm-dev@lists.squeakfoundation.org Subject: Strange InvalidDirectoryErrors on Unix Date: Mon, 09 Apr 2007 22:30:32 -0700
Hi Folks -
I had an odd effect today and I'm wondering if other people might have seen something similar in the past. One of our Linux servers (which has been running happily for a week) has an update process running which every five minutes checks to see if there is new data on the disk and if so, updates itself from it.
Today, I noticed that it stopped updating itself and investigating showed that it hit repeatedly an "InvalidDirectoryError" when trying to update itself. Trying to understand what was going on I went into the system life via VNC and stepped through the update method and suddenly it started working again! No more InvalidDirectoryErrors, updating went fine.
I'm at a complete loss as what might have caused this error. Unfortunately (since I was doing it on the life system) I couldn't investigate the error condition closer but there is a possibility that directory service had been used from different threads. Anyone having any ideas? (the only thing I am certain is that attaching VNC was *not* what it made it working again - I saw the error while I was in there with VNC and it became working again after I stepped through the method).
Any help is greatly appreciated. So are similar experiences and workarounds for the issue. The server itself is running Fedora Core 4.
Cheers,
- Andreas
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