Bug 3000

Summary:	Handle leak upon oneway invocation with RW wait startegy
Product:	TAO	Reporter:	ciju john <john_c>
Component:	ORB	Assignee:	ciju john <john_c>
Status:	RESOLVED FIXED
Severity:	major	CC:	mcorino, mitza
Priority:	P3
Version:	1.6.5
Hardware:	All
OS:	All
Bug Depends on:	2935
Bug Blocks:
Attachments:	Demostrate handle loss when making oneway invocation using RW wait startegy.

Description ciju john 2007-07-23 11:47:49 CDT

When using the RW wait startegy, the Transport_Cache_Manager::find_transport() temporarily removes the selected handler from the reactor read list. This is supposed to be undone in the wait strategy TAO_Wait_On_Read::wait(). However since in one-way invocations, the wait isn't done the handle gets lost.

This is demonstrated in the attached test (a modification of the $TAO_ROOT/tests/CallbackTest). A server using RW wait makes a oneway callback to the client(). The client starts upon a fixed endpoint. Since the server handle wasn't put back into the reactor read list, the client connection closure goes undetected. When a second client comes online, the server reuses the half-closed connection to send the one-way callback. This deadlocks.

./run_test.pl  // Tests the default wait startegy (LF).

./run_test.pl default  // Tests using the RW wait startegy.

Ciju

Comment 1 ciju john 2007-07-23 11:49:24 CDT

Created attachment 823 [details]
Demostrate handle loss when making oneway invocation using RW wait startegy.

Comment 2 Johnny Willemsen 2007-07-23 12:45:16 CDT

feel free to commit the regression test into the repo. Do you want this be handled as blocker for x.5.10 (you did put severity on blocker)?

Comment 3 ciju john 2007-07-23 12:58:23 CDT

> ------- Comment #2 from jwillemsen@remedy.nl  2007-07-23 12:45 -------
> feel free to commit the regression test into the repo.

Ok.

> Do you want this be
> handled as blocker for x.5.10 (you did put severity on blocker)?

No. I don't think the release should be blocked due to this (this is a
corner case that occurs rarely). I will change it to major. A solution
for this should refactoring out this code (removing handle from the
reactor handle list) from the Transport_Cache and move it completely
into the wait strategy.

Ciju

Comment 4 Johnny Willemsen 2007-07-23 13:01:30 CDT

do you also plan to handle this yourself, if so, please assign the bug to yourself

Comment 5 ciju john 2007-07-23 13:06:40 CDT

I wasn't planning on it. I just wanted to document this problem (interestingly I found this while debugging a DDS issue). I will accept the bug, but can't say when I will be able to work on it.

Ciju

Comment 6 Johnny Willemsen 2007-08-27 08:31:41 CDT

still failing with x.5.10

Comment 7 Johnny Willemsen 2007-09-26 07:41:52 CDT

Reassign to john_c@ociweb.com, he indicated he was willing to accept

Comment 8 Johnny Willemsen 2008-07-29 13:12:10 CDT

revert change below when fixed

Tue Jul 29 18:11:32 UTC 2008  Johnny Willemsen  <jwillemsen@remedy.nl>

        * bin/tao_orb_tests.lst:
          TAO/tests/Bug_3000_Regression fails because that issue remains
          unresolved, added !FIXED_BUGS_ONLY.

Comment 9 Martin Corino 2011-11-30 02:25:38 CST

Activated this test on all builds and it runs perfectly as far as I can tell. It seems recent changes to RW strategy (and/or other changes since the submit of this bug) have resolved this issue.