Bug 296 - Incorrect condition variable used with multiple reactors.
Summary: Incorrect condition variable used with multiple reactors.
Status: RESOLVED FIXED
Alias: None
Product: TAO
Classification: Unclassified
Component: ORB (show other bugs)
Version: 1.0.3
Hardware: All All
: P2 critical
Assignee: Irfan Pyarali
URL:
Depends on: 886
Blocks:
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Reported: 1999-09-03 15:40 CDT by Carlos O'Ryan
Modified: 2001-08-01 18:45 CDT (History)
1 user (show)

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Description Carlos O'Ryan 1999-09-03 15:40:45 CDT 
To support multiple reactors (we have one per priority) we
also need multiple leader follower sets, but the leader follower set
stores a condition variable in TSS storage (they need one per thread).

	There is a problem here because we could use condition
variables with a mismatched lock (the lock for the condition variable
is per-reactor).

The reason why we use a condition variable in TSS is to amortize its creation
time. It is probably as easy to use a pool of condition variables pre-allocated
in the TAO_Leader_Follower class.
Comment 1 Carlos O'Ryan 1999-09-03 15:41:59 CDT 
The ORB core team is in charge of this bug, but Fred is acting as pointman.
Comment 2 Fred Kuhns 1999-09-03 17:09:59 CDT 
accepting the point
Comment 3 Carlos O'Ryan 2000-06-06 16:58:09 CDT 
Marina and company have taken the leadership for the RT-CORBA stuff.
It is possible that with the new standard interfaces this one bug has become
obsolete, they know better, so I'm asking them to look at the bugs.
Comment 4 Irfan Pyarali 2000-06-06 17:12:26 CDT 
The new RT-CORBA code should address this.
Comment 5 Marina Spivak 2000-12-03 00:30:53 CST 
Irfan will address this with his threadpool work.
Comment 6 Irfan Pyarali 2000-12-18 13:53:34 CST 
Accepted
Comment 7 Carlos O'Ryan 2001-02-07 20:51:41 CST 
This one is going to be a critical problem, specially once the RT CORBA thread
pools are implemented.
Comment 8 Nanbor Wang 2001-06-21 07:19:10 CDT 
Moved it out of the vlocker list. As Irfan is implementing the resource-per-
lane stuff for the post 1.2 timeframe, he would be addressing this issue only 
then.
Comment 9 Carlos O'Ryan 2001-07-26 14:33:51 CDT 
The fixes for bug 886 include a fix for this problem.  I'm adding a dependency 
to remind myself of closing this bug when I commit the 886 fixes.
Comment 10 Carlos O'Ryan 2001-08-01 18:45:40 CDT 
The bug has been fixed, basically the condition variables are allocated from a
free list kept on the Leader_Follower set, this guarantees that the right
condition variable and mutex is used for each TAO_Leader_Follower class. Check
the following ChangeLog entry for details:

Wed Aug  1 16:05:36 2001  Carlos O'Ryan  <coryan@uci.edu>