[#LANG-334] Enum is not thread-safe

Commons Lang

Enum is not thread-safe

Created: 14/May/07 10:30 PM Updated: 05/Sep/07 10:14 AM

Return to search

Component/s:

None

Affects Version/s:

None

Fix Version/s:

2.4

Time Tracking:

Not Specified

File Attachments:

File Name	Date Attached	Attached By	Size
334.patch	2007-07-28 04:14 AM	Jason Madden	2 kB
EnumPlay.java	2007-06-06 03:24 PM	Henri Yandell	1 kB

Resolution Date:

05/Sep/07 10:14 AM

Description

« Hide

Enum uses no synchronization. Even if you assume that instances are only declared statically, the cEnumClasses map is global and can be written to when a thread triggers static initialization of B.class while some other thread is doing getEnumList(A.class). Unsynchronized access of a map undergoing mutation is not thread-safe.

This isn't theoretical. We're seeing ValuedEnum.getEnum(X.class, 0) return null after returning the correct value over 100,000 times, and then return the correct value again on the next invocation.

All

Comments

Work Log

Change History

Subversion Commits

Sort Order:

Henri Yandell made changes - 27/May/07 06:43 AM

Field	Original Value	New Value
Fix Version/s		2.3.1 [ 12312481 ]

Henri Yandell made changes - 06/Jun/07 03:24 PM

Attachment

EnumPlay.java [ 12359088 ]

Jason Madden made changes - 28/Jul/07 04:14 AM

Attachment

334.patch [ 12362719 ]

Henri Yandell made changes - 24/Aug/07 05:49 PM

Comment

[ Something else to consider. If we do synchronizedMap; would Hashtable be better. ie) any null values expected? ]

Henri Yandell made changes - 05/Sep/07 10:14 AM

Status	Open [ 1 ]	Closed [ 6 ]
Resolution		Fixed [ 1 ]