[Jikesrvm-issues] [jira] Created: (RVM-115) Finish removing all uses of LogicallyUninterruptible

Finish removing all uses of LogicallyUninterruptible
----------------------------------------------------

                 Key: RVM-115
                 URL: http://jira.codehaus.org/browse/RVM-115
             Project: RVM
          Issue Type: Improvement
          Components: Runtime
            Reporter: David Grove
            Priority: Minor
             Fix For: 2.9.2


Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).

We should finish this work item and finally kill LogicallyUninterruptible.

In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.



--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

     [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

David Grove updated RVM-115:
----------------------------

    Fix Version/s:     (was: 3.0)
                   3.0.1

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Priority: Minor
>             Fix For: 3.0.1
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW!
Studies have shown that voting for your favorite open source project,
along with a healthy diet, reduces your potential for chronic lameness
and boredom. Vote Now at http://www.sourceforge.net/community/cca08
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

     [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ian Rogers reassigned RVM-115:
------------------------------

    Assignee: Ian Rogers

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Assignee: Ian Rogers
>            Priority: Minor
>             Fix For: 3.0.1
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

     [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ian Rogers updated RVM-115:
---------------------------

    Fix Version/s:     (was: 3.0.1)
                   3.0

Most of the work of this is done by RVM-598. The remaining cases should be tidied up for 3.0.

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Assignee: Ian Rogers
>            Priority: Minor
>             Fix For: 3.0
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

    [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=143180#action_143180 ]

Ian Rogers commented on RVM-115:
--------------------------------

In Space.acquire (which is an uninterruptible class):

  public final Address acquire(int pages) {
    boolean allowPoll = !Plan.gcInProgress() && Plan.isInitialized() && !VM.collection.isEmergencyAllocation();

    /* First check page budget and poll if necessary */
    if (!pr.reservePages(pages)) {
      /* Need to poll, either fixing budget or requiring GC */
      if (allowPoll && VM.activePlan.global().poll(false, this)) {
        pr.clearRequest(pages);
        return Address.zero(); // GC required, return failure
      }
    }


the call to poll may context switch, as this breaks the uninterruptible guarantee poll is annotated LogicallyUninterruptible. Having uninterruptible code that can switch context is invalid, instead the code should be annotated Unpreemptible (a weaker guarantee that the compiler won't place implicit scheduling code into the JIT generated code). To get rid of the LogicallyUninterruptible and clean up this code there are 2 solutions:

1) mark Space.acquire as unpreemptible and then mark every uninterruptible MMTk routine that calls it unpreemptible. This is undesirable as it means we mark collector phases as unpreemptible, whereas they do satisfy uninterruptibility and we should enforce this.

2) create an uninterruptible version of Space.acquire and anything that calls it, mark Space.acquire and anything that calls it unpreemptible. In the collector phases use uninterruptible versions of the code.

I believe 2 is the way we should solve this problem but does mean a fairly large change to MMTk. If I can get a quick response we can make it into 3.0.

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Assignee: Ian Rogers
>            Priority: Minor
>             Fix For: 3.0
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

    [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=143191#action_143191 ]

Ian Rogers commented on RVM-115:
--------------------------------

This is fixed in the RVM in r14800, r14791 and r14789. Logically uninterruptible still needs removing from MMTk, see the comment above.

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Assignee: Ian Rogers
>            Priority: Minor
>             Fix For: 3.0
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues

     [ http://jira.codehaus.org/browse/RVM-115?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ian Rogers updated RVM-115:
---------------------------

         Assignee: Daniel Frampton  (was: Ian Rogers)
    Fix Version/s:     (was: 3.0)
                   3.0.1

> Finish removing all uses of LogicallyUninterruptible
> ----------------------------------------------------
>
>                 Key: RVM-115
>                 URL: http://jira.codehaus.org/browse/RVM-115
>             Project: RVM
>          Issue Type: Improvement
>          Components: Runtime
>            Reporter: David Grove
>            Assignee: Daniel Frampton
>            Priority: Minor
>             Fix For: 3.0.1
>
>
> Several years ago Perry, Daniel, and I started removing uses of LogicallyUninterruptible and replacing them with UninterruptibleNoWarn or Unpremptible (depending on the actual semantics of each usage...).
> We should finish this work item and finally kill LogicallyUninterruptible.
> In addition to being cleaner, this change could also allow us to do further optimization of uninterruptible code (for example since uninteruptible code is not allowed to raise exceptions (NullPointer, ArrayBoundsCheck), we could in principle compile uninterruptible code without nullcheck/boundcheck operations.  Whether or not this is actually a good idea is less clear, but it isn't even possible to safely try this until we do the cleanups and make Uninterruptibility a strictly enforced property with fewer loopholes.

--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

       

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Jikesrvm-issues mailing list
Jikesrvm-issues@...
https://lists.sourceforge.net/lists/listinfo/jikesrvm-issues