Comment 116 for bug 1684993

Reviewed: https://review.opencontrail.org/47019
Committed: http://github.com/Juniper/contrail-packages/commit/8f588c91458040361999defe59fed426f20e815b
Submitter: Zuul (<email address hidden>)
Branch: R4.1

commit 8f588c91458040361999defe59fed426f20e815b
Author: Ananth Suryanarayana <email address hidden>
Date: Mon Oct 15 12:21:28 2018 -0700

Do not insert already sleeping tbb task back into sleeping list

During testing, it was found that tbb sleeping threads singly linked
list was corrupted and had become circular. This seemingly caused
my_slack count to get permanently stuck at -1, as the sleeping list
traversal would potentially never end.

During testing, using a specific assert, it was confirmed that duplicate
insertion did happen.

Fixed it by modifying the sleeing threads singly linked list into a
doubly linked list and then making sure that a thread if already in
the list is never prepended back as the head of the list.

https://github.com/01org/tbb/issues/86

With this change, libtbb.so.2 is provided directly from contrail-lib
package.

Change-Id: I07416601cd9be658d75309caa0917d3c61d9e427
Closes-Bug: #1684993