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Posted to dev@openjpa.apache.org by "Rick Curtis (JIRA)" <ji...@apache.org> on 2009/07/09 00:01:15 UTC
[jira] Created: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
NPE in UUIDGenerator.initializeForType1()
-----------------------------------------
Key: OPENJPA-1168
URL: https://issues.apache.org/jira/browse/OPENJPA-1168
Project: OpenJPA
Issue Type: Bug
Components: lib
Reporter: Rick Curtis
Assignee: Rick Curtis
Fix For: 1.3.0, 2.0.0
When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
Scenario:
Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Commented: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Michael Dick (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12728994#action_12728994 ]
Michael Dick commented on OPENJPA-1168:
---------------------------------------
Hi Rick,
I'm unable to hit the timing window you mention on my system, but your explanation is sound.
That said there's still a window where IP can be initialized (non null) but not copied. Another thread could hit this window when IP was empty and get a non-unique id. It's probably safer to set a different flag at the end of the method and key off that instead of IP or RANDOM.
Thanks for the patch though - I doubt this was easy to find.
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Rick Curtis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Curtis updated OPENJPA-1168:
---------------------------------
Attachment: OPENJPA-1168.patch
Nice catch Mike.
I updated the patch as recommended.
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Commented: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Milosz Tylenda (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12729310#action_12729310 ]
Milosz Tylenda commented on OPENJPA-1168:
-----------------------------------------
This reminds me of a test case which sometimes fails for me while running against MySQL and which I did not have time to look at. Maybe this is connected although the test case is single-threaded. The stack trace I am receiving is:
testDefaultValues(org.apache.openjpa.persistence.generationtype.TestGeneratedValues) Time elapsed: 0.787 sec <<< FAILURE!
junit.framework.AssertionFailedError
at junit.framework.Assert.fail(Assert.java:47)
at junit.framework.Assert.assertTrue(Assert.java:20)
at junit.framework.Assert.assertFalse(Assert.java:34)
at junit.framework.Assert.assertFalse(Assert.java:41)
at org.apache.openjpa.persistence.generationtype.TestGeneratedValues.testDefaultValues(TestGeneratedValues.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at org.apache.openjpa.persistence.test.PersistenceTestCase.runBare(PersistenceTestCase.java:466)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at org.apache.openjpa.persistence.test.PersistenceTestCase.run(PersistenceTestCase.java:181)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at sun.reflect.GeneratedMethodAccessor58.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.maven.surefire.junit.JUnitTestSet.execute(JUnitTestSet.java:213)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:127)
at org.apache.maven.surefire.Surefire.run(Surefire.java:177)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:345)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1009)
The TestGeneratedValues.java:49 contains:
assertFalse(gv.getUuidstring().equals(gv2.getUuidstring()));
This means UUID generator sometimes generates duplicates.
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch, OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Rick Curtis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Curtis updated OPENJPA-1168:
---------------------------------
Attachment: OPENJPA-1168.patch
Fixed a problem in the test case that was introduced because of the previous patch.
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch, OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Rick Curtis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Curtis updated OPENJPA-1168:
---------------------------------
Attachment: OPENJPA-1168.patch
The patch includes a test case and the fix for this issue.
Since this bug is a timing window, running this test case against an un-patched tree may work from time to time. Please let me know if you want me to post some more information in the test case about why I did what I did.
- Rick
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Rick Curtis
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Rick Curtis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Curtis updated OPENJPA-1168:
---------------------------------
Attachment: (was: OPENJPA-1168.patch)
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Donald Woods (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Donald Woods updated OPENJPA-1168:
----------------------------------
Fix Version/s: (was: 2.0.0)
2.0.0-M3
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0-M3
>
> Attachments: OPENJPA-1168.patch, OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Resolved: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Michael Dick (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Michael Dick resolved OPENJPA-1168.
-----------------------------------
Resolution: Fixed
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch, OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Assigned: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Michael Dick (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Michael Dick reassigned OPENJPA-1168:
-------------------------------------
Assignee: Michael Dick
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Assignee: Michael Dick
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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[jira] Updated: (OPENJPA-1168) NPE in
UUIDGenerator.initializeForType1()
Posted by "Rick Curtis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/OPENJPA-1168?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Curtis updated OPENJPA-1168:
---------------------------------
Patch Info: [Patch Available]
Assignee: (was: Rick Curtis)
> NPE in UUIDGenerator.initializeForType1()
> -----------------------------------------
>
> Key: OPENJPA-1168
> URL: https://issues.apache.org/jira/browse/OPENJPA-1168
> Project: OpenJPA
> Issue Type: Bug
> Components: lib
> Reporter: Rick Curtis
> Fix For: 1.3.0, 2.0.0
>
> Attachments: OPENJPA-1168.patch
>
>
> When UUIDGenerator.createType1() is called by more than one thread at *nearly* the same time AND UUIDGenerator.createType1() wasn't called previously, a small timing window exists where a NPE will result.
> Scenario:
> Thread 1 calls UUIDGenerator.createType1() and RANDOM == null so initializeForType1() is called. While that thread is in initializeForType1(), it sets the static variable RANDOM so that value is no longer null. Now Thread 2 calls UUIDGenerator.createType1() and RANDOM is no longer null, so it proceeds to the call System.arraycopy(IP, 0, uuid, 10, IP.length);. At this point Thread 1 hasn't got to initializing IP yet, so Thread 2 gets hits a NPE.
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