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EclipseLink/Bugs/256277

< EclipseLink‎ | Bugs
Revision as of 16:53, 5 January 2009 by Michael.obrien.oracle.com (Talk | contribs) (→‎Bug Analysis Document: 256277: Endless loop on @PrePersist using a nested Persist)

Bug Analysis Document: 256277: Endless loop on @PrePersist using a nested Persist


Document History

Date Author Version Description & Notes
20080105 Michael O'Brien 1.0 Initial reproduction use cases

Overview

This bug is encountered when a secondary persist is executed inside of a @PrePersist callback method on the Entity being itself persisted. There are two use cases here, one when the secondary entity persist contains its own @PrePersist callback with a persist - causing an infinite loop, the second use case is when the secondary entity persisted does not do a persist in it's own @PrePersist.

Concepts

JPA Specification Notes

Here is what the JPA specification says about performing persists inside the @PrePersist method. Essentially it states that we should not be performing persists inside a @PrePersist callback - however it is the responsibility of the container to handle any that may be done.

JPA 1.0 Specification

  • P58 Section 3.5
    • "In general, portable applications should not invoke EntityManager or Query operations, access other entity instances, or modify relationships in a lifecycle callback method.[19]"
    • "[19] The semantics of such operations may be standardized in a future release of this specification."

JPA 2.0 Specification

  • P82 Section 3.5.1
    • "In general, portable applications should not invoke EntityManager or Query operations, access other entity instances, or modify relationships within the same persistence context.[34] A lifecycle callback method may modify the non-relationship state of the entity on which it is invoked."
    • "[34] The semantics of such operations may be standardized in a future release of this specification."


Reproduction

Prerequisites

  • Run tests out of container on an SE persitence unit
  • At least two entities must be persisted to avoid performance optimization code for a single entity
  • Two different entity classes are required
  • Test must commit more than one object so that the non-performance else clause in CommitManager.commitAllObjectsWithChangeSet() is used
  • Test must perform a change on an existing object that is already persisted
  • Set FlushMode
    • entityManager.setFlushMode(FlushModeType.AUTO);
  • Set a @PrePersist method callback on an Entity that does not perform a secondary persist
  • Set a @PrePersist method callback on an Entity that performs a secondary persist
@Entity
public class Leaf implements Serializable {
...
    @PrePersist
    // 256277: test prePersist without a secondary nested persist
    public void prePersist() {
        setState("0000");
    }
...
}
 
@Entity
public class Cell implements Serializable {
...    
    @PrePersist
    // 256277: test prePersist with a nested persist
    public void prePersist() {
        setState("9999");
        // get a reference to the entityManager and perform a persist inside this prePersist
        EntityManager entityManager = TestClient.staticEntityManager;
        processInsert(entityManager);
    }
 
    /**
     * An infinite loop will occur if we persist Cell entities within this Cell.prePersist() as it contains a persist.
     * Normal functionality will occur if we persist Leaf entites (which do not contain a persist in their PrePersist callback)
     * @param entityManager
     */
    private void processInsert(EntityManager entityManager) {
        // create 2 cells (to avoid performance optimization for 1 entity)  and link them
        int numCells = 2;
        List<Cell> cells = new ArrayList<Cell>();
        //List<Leaf> cells = new ArrayList<Leaf>();
        for(int i=0; i < numCells; i++) {
            cells.add(new Cell());
            //cells.add(new Leaf());
        }
 
        // link internal cells
        for(int i=1; i < cells.size() - 1; i++) {
            cells.get(i).setLeft(cells.get(i - 1));
            cells.get(i).setRight(cells.get(i + 1));
        }
 
        // link edges
        cells.get(0).setLeft(cells.get(cells.size() - 1));
        cells.get(0).setRight(cells.get(cells.size() - 1));
        cells.get(cells.size() - 1).setLeft(cells.get(0));
        cells.get(cells.size() - 1).setRight(cells.get(0));
        try {
            // Cache objects
            //entityManager.getTransaction().begin();
            for(int i=0; i < cells.size(); i++) {                
                entityManager.persist(cells.get(i));
                System.out.println("_processInsert() Inserted: " + cells.get(i));
            }
            // Store objects        
            entityManager.flush();
            //entityManager.getTransaction().commit();
        } catch (Exception e) {
            e.printStackTrace();
        }        
    }
...


Use Case 1: Persist other Entity (with its own @PrePersist and persist) inside @PrePersist callback

This use case currently causes an infinite loop on the following line up to build 20090105. 

    EntityClassListener(EntityListener).prePersist(DescriptorEvent) line: 412

Use Case 2: Persist other Entity (with its own @PrePersist with a persist) inside @PrePersist callback

Normal functionality with no infinite loop.

Use Case 3: Persist other Entity (without its own @PrePersist) inside @PrePersist

Normal functionality with no infinite loop.

Analysis Constraints

Design / Functionality

Testing

Use Case 1: Output of infinite loop

The following logs and stacktrace illustrate the current infinite loop behavior when performing a @PrePersist inside a @PrePersist as a result of a persist in this callback method.

Entity @PrePersist callback code

The @PrePersist code is the same as the entity requirements above and UC2 except that we persist Cell entities which contain a nested persist in their @PrePersist callback. 

 
    /**
     * An infinite loop will occur if we persist Cell entities within this Cell.prePersist() as it contains a persist.
     * Normal functionality will occur if we persist Leaf entites (which do not contain a persist in their PrePersist callback)
     * @param entityManager
     */
    private void processInsert(EntityManager entityManager) {
        // create 2 cells (to avoid performance optimization for 1 entity)  and link them
        int numCells = 2;
        List<Cell> cells = new ArrayList<Cell>();
        //List<Leaf> cells = new ArrayList<Leaf>();
        for(int i=0; i < numCells; i++) {
            cells.add(new Cell());
            //cells.add(new Leaf());
        }
...

StackTrace

TestClient [Java Application]	
	org.eclipse.persistence.example.TestClient at localhost:2561	
		Thread [main] (Suspended (breakpoint at line 112 in Cell))	
			Cell.processInsert(EntityManager) line: 112	
			Cell.prePersist() line: 69	
			NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]	
			NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39	
			DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25	
			Method.invoke(Object, Object...) line: 597	
			PrivilegedAccessHelper.invokeMethod(Method, Object, Object[]) line: 344	
			EntityClassListener(EntityListener).invokeMethod(Method, Object, Object[], DescriptorEvent) line: 297	
			EntityClassListener.invokeMethod(String, DescriptorEvent) line: 64	
			EntityClassListener(EntityListener).prePersist(DescriptorEvent) line: 412	
			DescriptorEventManager.notifyListener(DescriptorEventListener, DescriptorEvent) line: 650	
			DescriptorEventManager.notifyEJB30Listeners(DescriptorEvent) line: 593	
			DescriptorEventManager.executeEvent(DescriptorEvent) line: 187	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNewObjectClone(Object, Object, ClassDescriptor) line: 3980	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNotRegisteredNewObjectForPersist(Object, ClassDescriptor) line: 3959	
			RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(Object, ClassDescriptor) line: 336	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNewObjectForPersist(Object, Map) line: 3903	
			EntityManagerImpl.persist(Object) line: 254	
			Cell.processInsert(EntityManager) line: 121	
			Cell.prePersist() line: 69	
...
			Cell.prePersist() line: 69	
			NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]	
			NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39	
			DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25	
			Method.invoke(Object, Object...) line: 597	
			PrivilegedAccessHelper.invokeMethod(Method, Object, Object[]) line: 344	
			EntityClassListener(EntityListener).invokeMethod(Method, Object, Object[], DescriptorEvent) line: 297	
			EntityClassListener.invokeMethod(String, DescriptorEvent) line: 64	
			EntityClassListener(EntityListener).prePersist(DescriptorEvent) line: 412	
			DescriptorEventManager.notifyListener(DescriptorEventListener, DescriptorEvent) line: 650	
			DescriptorEventManager.notifyEJB30Listeners(DescriptorEvent) line: 593	
			DescriptorEventManager.executeEvent(DescriptorEvent) line: 187	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNewObjectClone(Object, Object, ClassDescriptor) line: 3980	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNotRegisteredNewObjectForPersist(Object, ClassDescriptor) line: 3959	
			RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(Object, ClassDescriptor) line: 336	
			RepeatableWriteUnitOfWork(UnitOfWorkImpl).registerNewObjectForPersist(Object, Map) line: 3903	
			EntityManagerImpl.persist(Object) line: 254	
			TestClient.processInsert() line: 176	
			TestClient.doQuery() line: 254	
			TestClient.main(String[]) line: 247	
	C:\jdk1.6.0\bin\javaw.exe (Jan 5, 2009 1:10:19 PM)

Logs

[EL Finest]: 2009.01.05 13:09:22.915--UnitOfWork(2804823)--Thread(Thread[main,5,main])--assign sequence to the object (1,210 -> org.eclipse.persistence.example.business.Cell@11024915( id: null state: null left: null right: null))
[EL Finest]: 2009.01.05 13:09:22.915--UnitOfWork(2804823)--Thread(Thread[main,5,main])--PERSIST operation called on: org.eclipse.persistence.example.business.Cell@8180602( id: null state: null left: null right: null).
[EL Finest]: 2009.01.05 13:09:22.930--UnitOfWork(2804823)--Thread(Thread[main,5,main])--assign sequence to the object (1,211 -> org.eclipse.persistence.example.business.Cell@8180602( id: null state: null left: null right: null))
Exception in thread "main" java.lang.StackOverflowError
	at java.text.DecimalFormat.setMinimumIntegerDigits(DecimalFormat.java:2677)
	at java.text.SimpleDateFormat.zeroPaddingNumber(SimpleDateFormat.java:1184)
	at java.text.SimpleDateFormat.subFormat(SimpleDateFormat.java:1125)
	at java.text.SimpleDateFormat.format(SimpleDateFormat.java:882)
	at java.text.SimpleDateFormat.format(SimpleDateFormat.java:852)
	at java.text.DateFormat.format(DateFormat.java:316)
	at org.eclipse.persistence.logging.AbstractSessionLog.getDateString(AbstractSessionLog.java:644)
	at org.eclipse.persistence.logging.AbstractSessionLog.getSupplementDetailString(AbstractSessionLog.java:654)
	at org.eclipse.persistence.logging.DefaultSessionLog.log(DefaultSessionLog.java:130)
	at org.eclipse.persistence.internal.sessions.AbstractSession.log(AbstractSession.java:2492)
	at org.eclipse.persistence.internal.sessions.AbstractSession.log(AbstractSession.java:3579)
	at org.eclipse.persistence.internal.sessions.AbstractSession.log(AbstractSession.java:3551)
	at org.eclipse.persistence.internal.sessions.AbstractSession.log(AbstractSession.java:3527)
	at org.eclipse.persistence.internal.sessions.AbstractSession.log(AbstractSession.java:3449)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.logDebugMessage(UnitOfWorkImpl.java:5106)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNotRegisteredNewObjectForPersist(UnitOfWorkImpl.java:3945)
	at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(RepeatableWriteUnitOfWork.java:336)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:3903)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:254)
	at org.eclipse.persistence.example.business.Cell.processInsert(Cell.java:121)
	at org.eclipse.persistence.example.business.Cell.prePersist(Cell.java:69)
	at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.persistence.internal.security.PrivilegedAccessHelper.invokeMethod(PrivilegedAccessHelper.java:344)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityListener.invokeMethod(EntityListener.java:297)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityClassListener.invokeMethod(EntityClassListener.java:64)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityListener.prePersist(EntityListener.java:412)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyListener(DescriptorEventManager.java:650)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyEJB30Listeners(DescriptorEventManager.java:593)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.executeEvent(DescriptorEventManager.java:187)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectClone(UnitOfWorkImpl.java:3980)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNotRegisteredNewObjectForPersist(UnitOfWorkImpl.java:3959)
	at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(RepeatableWriteUnitOfWork.java:336)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:3903)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:254)
	at org.eclipse.persistence.example.business.Cell.processInsert(Cell.java:121)
	at org.eclipse.persistence.example.business.Cell.prePersist(Cell.java:69)
	at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.eclipse.persistence.internal.security.PrivilegedAccessHelper.invokeMethod(PrivilegedAccessHelper.java:344)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityListener.invokeMethod(EntityListener.java:297)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityClassListener.invokeMethod(EntityClassListener.java:64)
	at org.eclipse.persistence.internal.jpa.metadata.listeners.EntityListener.prePersist(EntityListener.java:412)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyListener(DescriptorEventManager.java:650)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.notifyEJB30Listeners(DescriptorEventManager.java:593)
	at org.eclipse.persistence.descriptors.DescriptorEventManager.executeEvent(DescriptorEventManager.java:187)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectClone(UnitOfWorkImpl.java:3980)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNotRegisteredNewObjectForPersist(UnitOfWorkImpl.java:3959)
	at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.registerNotRegisteredNewObjectForPersist(RepeatableWriteUnitOfWork.java:336)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:3903)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.persist(EntityManagerImpl.java:254)
	at org.eclipse.persistence.example.business.Cell.processInsert(Cell.java:121)
	at org.eclipse.persistence.example.business.Cell.prePersist(Cell.java:69)
	at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)

Use Case 2: Output normal

The following logs and stacktrace illustrate the current normal behavior when performing a @PrePersist inside a @PrePersist callback that has no nested persist.

Entity @PrePersist callback code

The @PrePersist code is the same as UC1 except that we persist Leaf entities which do not have a persist in their @PrePersist callback. 

 
    /**
     * An infinite loop will occur if we persist Cell entities within this Cell.prePersist() as it contains a persist.
     * Normal functionality will occur if we persist Leaf entites (which do not contain a persist in their PrePersist callback)
     * @param entityManager
     */
    private void processInsert(EntityManager entityManager) {
        // create 2 cells (to avoid performance optimization for 1 entity)  and link them
        int numCells = 2;
        //List<Cell> cells = new ArrayList<Cell>();
        List<Leaf> cells = new ArrayList<Leaf>();
        for(int i=0; i < numCells; i++) {
            //cells.add(new Cell());
            cells.add(new Leaf());
        }
...

StackTrace

Logs

[EL Finer]: 2009.01.05 15:33:57.746--ClientSession(12213370)--Connection(7896426)--Thread(Thread[main,5,main])--begin transaction
[EL Finest]: 2009.01.05 15:33:57.746--UnitOfWork(5998631)--Thread(Thread[main,5,main])--Execute query InsertObjectQuery(org.eclipse.persistence.example.business.Cell@10040532( id: 2551 state: 9999 left: 2551 right: 2551))
[EL Finest]: 2009.01.05 15:33:57.746--UnitOfWork(5998631)--Thread(Thread[main,5,main])--Execute query WriteObjectQuery(org.eclipse.persistence.example.business.Cell@10040532( id: 2551 state: 9999 left: 2551 right: 2551))
[EL Fine]: 2009.01.05 15:33:57.746--ClientSession(12213370)--Connection(7896426)--Thread(Thread[main,5,main])--INSERT INTO EL_CELL (ID, STATE, TSEQ, RIGHT_ID) VALUES (?, ?, ?, ?)
	bind => [2551, 9999, null, null]
[EL Fine]: 2009.01.05 15:33:57.746--ClientSession(12213370)--Connection(7896426)--Thread(Thread[main,5,main])--UPDATE EL_CELL SET STATE = ?, RIGHT_ID = ? WHERE (ID = ?)
	bind => [9999, 2551, 2551]
[EL Finest]: 2009.01.05 15:33:57.746--UnitOfWork(5998631)--Thread(Thread[main,5,main])--Execute query InsertObjectQuery(org.eclipse.persistence.example.business.Leaf@9470766( id: 1003 state: 0000 left: 1003 right: 1003))
[EL Finest]: 2009.01.05 15:33:57.746--UnitOfWork(5998631)--Thread(Thread[main,5,main])--Execute query WriteObjectQuery(org.eclipse.persistence.example.business.Leaf@9470766( id: 1003 state: 0000 left: 1003 right: 1003))
[EL Fine]: 2009.01.05 15:33:57.746--ClientSession(12213370)--Connection(7896426)--Thread(Thread[main,5,main])--INSERT INTO EL_LEAF (ID, STATE, TSEQ, RIGHT_ID) VALUES (?, ?, ?, ?)
	bind => [1003, 0000, null, null]
[EL Fine]: 2009.01.05 15:33:57.746--ClientSession(12213370)--Connection(7896426)--Thread(Thread[main,5,main])--UPDATE EL_LEAF SET STATE = ?, RIGHT_ID = ? WHERE (ID = ?)
	bind => [0000, 1003, 1003]
[EL Finer]: 2009.01.05 15:33:57.761--UnitOfWork(5998631)--Thread(Thread[main,5,main])--begin unit of work commit

API

GUI

Config files

Documentation

Open Issues

Issue # Owner Description / Notes
I1 mobrien Verify that Entity containing the @PrePersist callback has been registered

Decisions

Issue # Description / Notes Decision

Future Considerations

During the research for this bug, the following items were identified as out of scope but are captured here as potential future enhancements. If agreed upon during the review process these should be logged in the bug system.

References

Retrieved from "https://wiki.eclipse.org/index.php?title=EclipseLink/Bugs/256277&oldid=135586"

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