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Posted to dev@cayenne.apache.org by ha...@pvv.ntnu.no on 2011/05/10 23:01:01 UTC

query cloneViaSerialization

Hello.

In the jstack-output I am looking at now, there are several threads doing
a Util.cloneViaSerialization on some basic prefetching for a SelectQuery.
Down the java.io.ObjectOutputStream road there is some locking going on.
Is Util.cloneViaSerialization really needed here? This is with 3.1M2.

Regards,
 - Tore.

"qtp1661944297-498" prio=10 tid=0x00007f48d0189000 nid=0x51ec in
Object.wait() [0x00007f48c37f4000]
   java.lang.Thread.State: WAITING (on object monitor)
	at java.lang.Object.wait(Native Method)
	- waiting on <0x00007f49bb212090> (a java.io.ObjectStreamClass$EntryFuture)
	at java.lang.Object.wait(Object.java:485)
	at java.io.ObjectStreamClass$EntryFuture.get(ObjectStreamClass.java:371)
	- locked <0x00007f49bb212090> (a java.io.ObjectStreamClass$EntryFuture)
	at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:305)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1114)
	at
java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1518)
	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1483)
	at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
	at org.apache.cayenne.util.Util.cloneViaSerialization(Util.java:346)
	at
org.apache.cayenne.query.BaseQueryMetadata.setPrefetchTree(BaseQueryMetadata.java:332)
	at
org.apache.cayenne.query.SelectQuery.setPrefetchTree(SelectQuery.java:416)
	at
org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startDisjointPrefetch(SelectQueryPrefetchRouterAction.java:116)
	at
org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startUnknownPrefetch(SelectQueryPrefetchRouterAction.java:135)
	at
org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:173)
	at
org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:179)
	at
org.apache.cayenne.query.SelectQueryPrefetchRouterAction.route(SelectQueryPrefetchRouterAction.java:54)
	at
org.apache.cayenne.query.SelectQuery.routePrefetches(SelectQuery.java:179)
	at org.apache.cayenne.query.SelectQuery.route(SelectQuery.java:169)
	at
org.apache.cayenne.access.DataDomainQueryAction.runQuery(DataDomainQueryAction.java:414)
	at
org.apache.cayenne.access.DataDomainQueryAction.access$000(DataDomainQueryAction.java:69)
	at
org.apache.cayenne.access.DataDomainQueryAction$2.transform(DataDomainQueryAction.java:395)
	at
org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:824)
	at
org.apache.cayenne.access.DataDomainQueryAction.runQueryInTransaction(DataDomainQueryAction.java:392)
	at
org.apache.cayenne.access.DataDomainQueryAction.execute(DataDomainQueryAction.java:121)
	at
org.apache.cayenne.access.DataDomain.onQueryNoFilters(DataDomain.java:706)
	at
org.apache.cayenne.access.DataDomain$DataDomainQueryFilterChain.onQuery(DataDomain.java:944)
	at org.apache.cayenne.access.DataDomain.onQuery(DataDomain.java:696)
	at
org.apache.cayenne.util.ObjectContextQueryAction.runQuery(ObjectContextQueryAction.java:336)
	at
org.apache.cayenne.util.ObjectContextQueryAction.executePostCache(ObjectContextQueryAction.java:104)
	at
org.apache.cayenne.util.ObjectContextQueryAction.execute(ObjectContextQueryAction.java:91)
	at org.apache.cayenne.access.DataContext.onQuery(DataContext.java:983)
	at org.apache.cayenne.access.DataContext.performQuery(DataContext.java:972)

Re: query cloneViaSerialization

Posted by Andrus Adamchik <an...@objectstyle.org>.
Actually just opened (and closed) a Jira to ensure it gets to the release notes: https://issues.apache.org/jira/browse/CAY-1567

On May 15, 2011, at 6:01 AM, Andrus Adamchik wrote:

> 
> On May 11, 2011, at 1:35 AM, Andrus Adamchik wrote:
> 
>> 
>> I guess that makes 'cloneViaSerialization' unusable for Cayenne stack classes. Specifically we should rewrite BaseQueryMetadata.setPrefetchTree(..) to clone PrefetchTreeNode manually, which should be pretty trivial.
> 
> BTW just committed this fix to trunk. (should've opened a Jira I guess).
> 
> Andrus

Re: query cloneViaSerialization

Posted by Tore Halset <ha...@pvv.ntnu.no>.
Wow, thanks!

On May 15, 2011, at 12:01, Andrus Adamchik <an...@objectstyle.org> wrote:

> 
> On May 11, 2011, at 1:35 AM, Andrus Adamchik wrote:
> 
>> 
>> I guess that makes 'cloneViaSerialization' unusable for Cayenne stack classes. Specifically we should rewrite BaseQueryMetadata.setPrefetchTree(..) to clone PrefetchTreeNode manually, which should be pretty trivial.
> 
> BTW just committed this fix to trunk. (should've opened a Jira I guess).
> 
> Andrus

Re: query cloneViaSerialization

Posted by Andrus Adamchik <an...@objectstyle.org>.
On May 11, 2011, at 1:35 AM, Andrus Adamchik wrote:

> 
> I guess that makes 'cloneViaSerialization' unusable for Cayenne stack classes. Specifically we should rewrite BaseQueryMetadata.setPrefetchTree(..) to clone PrefetchTreeNode manually, which should be pretty trivial.

BTW just committed this fix to trunk. (should've opened a Jira I guess).

Andrus

Re: query cloneViaSerialization

Posted by Andrus Adamchik <an...@objectstyle.org>.
I just committed a removal of a synchronization on the ByteArrayOutputStream method inside cloneViaSerialization, which was unneeded. However I think it is not the cause of your lockup. Instead it is a synchronized block inside ObjectStreamClass. So that's a JVM class that we can't control. 

I guess that makes 'cloneViaSerialization' unusable for Cayenne stack classes. Specifically we should rewrite BaseQueryMetadata.setPrefetchTree(..) to clone PrefetchTreeNode manually, which should be pretty trivial.

Andrus

On May 11, 2011, at 12:08 AM, halset@pvv.ntnu.no wrote:

> One more thing. In this single jstack output, there are 15 threads/stacks
> doing Util.cloneViaSerialization like the stack below!
> 
> - Tore.
> 
>> Hello.
>> 
>> In the jstack-output I am looking at now, there are several threads doing
>> a Util.cloneViaSerialization on some basic prefetching for a SelectQuery.
>> Down the java.io.ObjectOutputStream road there is some locking going on.
>> Is Util.cloneViaSerialization really needed here? This is with 3.1M2.
>> 
>> Regards,
>> - Tore.
>> 
>> "qtp1661944297-498" prio=10 tid=0x00007f48d0189000 nid=0x51ec in
>> Object.wait() [0x00007f48c37f4000]
>>  java.lang.Thread.State: WAITING (on object monitor)
>> 	at java.lang.Object.wait(Native Method)
>> 	- waiting on <0x00007f49bb212090> (a
>> java.io.ObjectStreamClass$EntryFuture)
>> 	at java.lang.Object.wait(Object.java:485)
>> 	at java.io.ObjectStreamClass$EntryFuture.get(ObjectStreamClass.java:371)
>> 	- locked <0x00007f49bb212090> (a java.io.ObjectStreamClass$EntryFuture)
>> 	at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:305)
>> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1114)
>> 	at
>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1518)
>> 	at
>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1483)
>> 	at
>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
>> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
>> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
>> 	at org.apache.cayenne.util.Util.cloneViaSerialization(Util.java:346)
>> 	at
>> org.apache.cayenne.query.BaseQueryMetadata.setPrefetchTree(BaseQueryMetadata.java:332)
>> 	at
>> org.apache.cayenne.query.SelectQuery.setPrefetchTree(SelectQuery.java:416)
>> 	at
>> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startDisjointPrefetch(SelectQueryPrefetchRouterAction.java:116)
>> 	at
>> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startUnknownPrefetch(SelectQueryPrefetchRouterAction.java:135)
>> 	at
>> org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:173)
>> 	at
>> org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:179)
>> 	at
>> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.route(SelectQueryPrefetchRouterAction.java:54)
>> 	at
>> org.apache.cayenne.query.SelectQuery.routePrefetches(SelectQuery.java:179)
>> 	at org.apache.cayenne.query.SelectQuery.route(SelectQuery.java:169)
>> 	at
>> org.apache.cayenne.access.DataDomainQueryAction.runQuery(DataDomainQueryAction.java:414)
>> 	at
>> org.apache.cayenne.access.DataDomainQueryAction.access$000(DataDomainQueryAction.java:69)
>> 	at
>> org.apache.cayenne.access.DataDomainQueryAction$2.transform(DataDomainQueryAction.java:395)
>> 	at
>> org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:824)
>> 	at
>> org.apache.cayenne.access.DataDomainQueryAction.runQueryInTransaction(DataDomainQueryAction.java:392)
>> 	at
>> org.apache.cayenne.access.DataDomainQueryAction.execute(DataDomainQueryAction.java:121)
>> 	at
>> org.apache.cayenne.access.DataDomain.onQueryNoFilters(DataDomain.java:706)
>> 	at
>> org.apache.cayenne.access.DataDomain$DataDomainQueryFilterChain.onQuery(DataDomain.java:944)
>> 	at org.apache.cayenne.access.DataDomain.onQuery(DataDomain.java:696)
>> 	at
>> org.apache.cayenne.util.ObjectContextQueryAction.runQuery(ObjectContextQueryAction.java:336)
>> 	at
>> org.apache.cayenne.util.ObjectContextQueryAction.executePostCache(ObjectContextQueryAction.java:104)
>> 	at
>> org.apache.cayenne.util.ObjectContextQueryAction.execute(ObjectContextQueryAction.java:91)
>> 	at org.apache.cayenne.access.DataContext.onQuery(DataContext.java:983)
>> 	at
>> org.apache.cayenne.access.DataContext.performQuery(DataContext.java:972)
>> 
>> 
>> 
>> 
> 
> 
>

Re: query cloneViaSerialization

Posted by ha...@pvv.ntnu.no.
One more thing. In this single jstack output, there are 15 threads/stacks
doing Util.cloneViaSerialization like the stack below!

 - Tore.

> Hello.
>
> In the jstack-output I am looking at now, there are several threads doing
> a Util.cloneViaSerialization on some basic prefetching for a SelectQuery.
> Down the java.io.ObjectOutputStream road there is some locking going on.
> Is Util.cloneViaSerialization really needed here? This is with 3.1M2.
>
> Regards,
>  - Tore.
>
> "qtp1661944297-498" prio=10 tid=0x00007f48d0189000 nid=0x51ec in
> Object.wait() [0x00007f48c37f4000]
>    java.lang.Thread.State: WAITING (on object monitor)
> 	at java.lang.Object.wait(Native Method)
> 	- waiting on <0x00007f49bb212090> (a
> java.io.ObjectStreamClass$EntryFuture)
> 	at java.lang.Object.wait(Object.java:485)
> 	at java.io.ObjectStreamClass$EntryFuture.get(ObjectStreamClass.java:371)
> 	- locked <0x00007f49bb212090> (a java.io.ObjectStreamClass$EntryFuture)
> 	at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:305)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1114)
> 	at
> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1518)
> 	at
> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1483)
> 	at
> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1400)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:330)
> 	at org.apache.cayenne.util.Util.cloneViaSerialization(Util.java:346)
> 	at
> org.apache.cayenne.query.BaseQueryMetadata.setPrefetchTree(BaseQueryMetadata.java:332)
> 	at
> org.apache.cayenne.query.SelectQuery.setPrefetchTree(SelectQuery.java:416)
> 	at
> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startDisjointPrefetch(SelectQueryPrefetchRouterAction.java:116)
> 	at
> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.startUnknownPrefetch(SelectQueryPrefetchRouterAction.java:135)
> 	at
> org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:173)
> 	at
> org.apache.cayenne.query.PrefetchTreeNode.traverse(PrefetchTreeNode.java:179)
> 	at
> org.apache.cayenne.query.SelectQueryPrefetchRouterAction.route(SelectQueryPrefetchRouterAction.java:54)
> 	at
> org.apache.cayenne.query.SelectQuery.routePrefetches(SelectQuery.java:179)
> 	at org.apache.cayenne.query.SelectQuery.route(SelectQuery.java:169)
> 	at
> org.apache.cayenne.access.DataDomainQueryAction.runQuery(DataDomainQueryAction.java:414)
> 	at
> org.apache.cayenne.access.DataDomainQueryAction.access$000(DataDomainQueryAction.java:69)
> 	at
> org.apache.cayenne.access.DataDomainQueryAction$2.transform(DataDomainQueryAction.java:395)
> 	at
> org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:824)
> 	at
> org.apache.cayenne.access.DataDomainQueryAction.runQueryInTransaction(DataDomainQueryAction.java:392)
> 	at
> org.apache.cayenne.access.DataDomainQueryAction.execute(DataDomainQueryAction.java:121)
> 	at
> org.apache.cayenne.access.DataDomain.onQueryNoFilters(DataDomain.java:706)
> 	at
> org.apache.cayenne.access.DataDomain$DataDomainQueryFilterChain.onQuery(DataDomain.java:944)
> 	at org.apache.cayenne.access.DataDomain.onQuery(DataDomain.java:696)
> 	at
> org.apache.cayenne.util.ObjectContextQueryAction.runQuery(ObjectContextQueryAction.java:336)
> 	at
> org.apache.cayenne.util.ObjectContextQueryAction.executePostCache(ObjectContextQueryAction.java:104)
> 	at
> org.apache.cayenne.util.ObjectContextQueryAction.execute(ObjectContextQueryAction.java:91)
> 	at org.apache.cayenne.access.DataContext.onQuery(DataContext.java:983)
> 	at
> org.apache.cayenne.access.DataContext.performQuery(DataContext.java:972)
>
>
>
>