[JAMES-1327] FileSystemBlobStrategy#getFile(ActiveMQBlobMessage) is not thread safe (throws "java.io.IOException: Unable to create directory")

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0-beta3
• Fix Version/s: 3.0-beta4
• Component/s: Queue
• Environment: At least Windows and Linux.
• Assignee: Norman Maurer
• Reporter: Michael Herrmann
• Created: 07/Oct/11 13:21
• Updated: 07/Oct/11 16:43
• Resolved: 07/Oct/11 16:43

Description

Consider org.apache.james.queue.activemq.FileSystemBlobStrategy#getFile(ActiveMQBlobMessage):

protected File getFile(ActiveMQBlobMessage message) throws JMSException, IOException {
...
// check if we need to create the queue folder
if (queueF.exists() == false) {
if (!queueF.mkdirs())

{ throw new IOException("Unable to create directory " + queueF.getAbsolutePath()); }

}
...
}

Suppose this method is called from two threads. If both threads get past the condition
if (queueF.exists() == false),
then the first one will create queueF. For the second, queueF.mkdirs() will then return false, which leads to an IOException even though everything is fine. I think the condition should be replaced by
if (!queueF.mkdirs() && !queueF.exists()).

Issue Links

• relates to: JAMES-1208 FileSystemBlobStrategy getFile doesn't fails, when a needed directory couldn't be created