[AXIS-2574] Reading an attachment (slowly) can cause resource deleted error

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.1
• Component/s: Basic Architecture
• Assignee: Jochen Wiedmann
• Reporter: Steve Sowerby
• Created: 19/Oct/06 10:16
• Updated: 26/May/22 15:49
• Resolved: 04/Nov/08 06:58

Description

When reading the data from an attachment we periodically get the following error:

java.io.IOException: Resource has been deleted.
at org.apache.axis.attachments.ManagedMemoryDataSource$Instream.read(ManagedMemoryDataSource.java:688)

Having run this throught a debugger and had a brief look at the code it seems to me there is a race condition of sorts.
The MemoryManagedDataSource that provides the InputStream has been marked as deleted by the finalize method of AttachmentPart.
So basically if the client doesn't read off the attachment fast enough then the writer will have finished and the AttachmentPart gets finalized and blam, you've got a deleted MemoryManagedDataSource.

I'm not sure what the best fix is. Perhaps the deletion should actually be some reference count rather than a simple boolean. That way the MemoryManagedDataSource gets deleted once all the writers and readers are done? Although perhaps then there would be an issue if the client was very slow to even open the attachment?

Issue Links

• relates to: AXIS-2948 Getting java.io.IOException while reading large size file