[jira] [Commented] (CSV-34) CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe
[ https://issues.apache.org/jira/browse/CSV-34?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13227352#comment-13227352 ] Emmanuel Bourg commented on CSV-34: --- volatile prevents the variables from being cached in the registers and creates a memory barrier, so that's not that surprising to see an impact on the performances. But I admit I didn't expect as much as 5%. That's probably because the parser calls the format properties many time on every character read. CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe Key: CSV-34 URL: https://issues.apache.org/jira/browse/CSV-34 Project: Commons CSV Issue Type: Bug Reporter: Sebb Fix For: 1.0 Attachments: CSVFormat.java CSVFormat describes itself as immutable, but it is not @Immutable - the class fields are all mutable. The methods that change the fields do so by creating a clone, and returning the changed clone. So in a sense the class is immutable. However, the normal expectation is that @Immutable classes are @ThreadSafe. CSVFormat is not thread-safe, because the fields are not volatile, and the fields are not written read using a common lock. The comment needs to be clarified or removed. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CSV-34) CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe
[ https://issues.apache.org/jira/browse/CSV-34?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13227264#comment-13227264 ] Emmanuel Bourg commented on CSV-34: --- Eventually I removed the volatile modifier, it was slowing the parser by about 5% in my tests. I replaced the clones by a constructor call as you suggested. CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe Key: CSV-34 URL: https://issues.apache.org/jira/browse/CSV-34 Project: Commons CSV Issue Type: Bug Reporter: Sebb Fix For: 1.0 Attachments: CSVFormat.java CSVFormat describes itself as immutable, but it is not @Immutable - the class fields are all mutable. The methods that change the fields do so by creating a clone, and returning the changed clone. So in a sense the class is immutable. However, the normal expectation is that @Immutable classes are @ThreadSafe. CSVFormat is not thread-safe, because the fields are not volatile, and the fields are not written read using a common lock. The comment needs to be clarified or removed. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (CSV-34) CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe
[ https://issues.apache.org/jira/browse/CSV-34?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13227307#comment-13227307 ] Sebb commented on CSV-34: - That's quite surprising. Obviously volatile will have some overhead, but I'm surprised it is as much as that, but then there are quite a few variables to be checked. CSVFormat describes itself as immutable, but it is not - in particular it is not thread-safe Key: CSV-34 URL: https://issues.apache.org/jira/browse/CSV-34 Project: Commons CSV Issue Type: Bug Reporter: Sebb Fix For: 1.0 Attachments: CSVFormat.java CSVFormat describes itself as immutable, but it is not @Immutable - the class fields are all mutable. The methods that change the fields do so by creating a clone, and returning the changed clone. So in a sense the class is immutable. However, the normal expectation is that @Immutable classes are @ThreadSafe. CSVFormat is not thread-safe, because the fields are not volatile, and the fields are not written read using a common lock. The comment needs to be clarified or removed. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
