[
https://issues.apache.org/jira/browse/PDFBOX-2862?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14630583#comment-14630583
]
John Hewson commented on PDFBOX-2862:
-------------------------------------
Ok, I might have figured it out. I don't think it was actually a static
initialization issue at all. While it's true that a GlyphList is conceptually
read-only, nameToUnicode was actually being written to as a cache by
toUnicode(code). So if one thread is copying a GlyphList via the copy
constructor and another is writing to the cache during a toUnicode(code) call,
then there is a concurrent access.
This problem can be solved without synchronization by introducing a separate,
non-shared map for per-instance caching.
> GlyphList doesn't appear to be thread safe in trunk...or user error?
> --------------------------------------------------------------------
>
> Key: PDFBOX-2862
> URL: https://issues.apache.org/jira/browse/PDFBOX-2862
> Project: PDFBox
> Issue Type: Bug
> Affects Versions: 2.0.0
> Reporter: Tim Allison
> Assignee: John Hewson
> Fix For: 2.0.0
>
> Attachments: batch-process-warn-first10klines.log.bz2
>
>
> This could be user error, but I'm getting the following when running trunk in
> a multithreaded environment.
> {noformat}
> Caused by: java.util.ConcurrentModificationException
> at java.util.HashMap$HashIterator.nextEntry(HashMap.java:922)
> at java.util.HashMap$EntryIterator.next(HashMap.java:962)
> at java.util.HashMap$EntryIterator.next(HashMap.java:960)
> at java.util.HashMap.putAllForCreate(HashMap.java:554)
> at java.util.HashMap.<init>(HashMap.java:298)
> at
> org.apache.pdfbox.pdmodel.font.encoding.GlyphList.<init>(GlyphList.java:114)
> at
> org.apache.pdfbox.text.PDFTextStreamEngine.<init>(PDFTextStreamEngine.java:103)
> at
> org.apache.pdfbox.text.PDFTextStripper.<init>(PDFTextStripper.java:196)
> at
> org.apache.tika.parser.pdf.PDF2XHTML.<init>(PDF2XHTML.java:106)
> at org.apache.tika.parser.pdf.PDF2XHTML.process(PDF2XHTML.java:133)
> at org.apache.tika.parser.pdf.PDFParser.parse(PDFParser.java:132)
> at
> org.apache.tika.parser.CompositeParser.parse(CompositeParser.java:281)
> ... 16 more
> {noformat}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
