Currently we have version 0.9.16 in RHEL 6.4. We would like to update to version 0.9.18 cause it has a lot of important bugfixes we would like to have in RHEL 6.5. It would be possible to backport all patches, but we want really most of them cause they improve libtevent.


Some background:
-----------------

We found these bugs cause of a customer (not a RH customer) having problems with the poll backend in winbind. After changing the winbind code to fully use libtevent epoll backend, winbind went down from running at 100% to nearly never seen in top.

Testing:
---------
There is no additional testing needed beside running the testsuite of libtevent. The tests we are running in Samba or sssd cover libtevent functionality too.


Here are some details about the changes:
-----------------------------------------

0.9.17 added a thread safe poll backend (not in use by samba or ipa/sssd). This is a small patch.

0.9.18 is a bugfix release, with a lot of fixes. A rebase would just be 
simpler for us. libtevent is a low-level library. Patches need to be tested 
well and we require testcases upstream from changes.

    - Adding new timer events is now faster, if there's
      a large number of timer events.
    
    - sigprocmask does not work on FreeBSD to stop further signals in a signal
      handler.
    
    - TEVENT_NUM_SIGNALS is calculated by configure in order
      to support realtime signals on freebsd.
    
    - ./configure --disable-python was fixed for the standalone build.
    
    - Several crash bugs in the poll backend are fixed.
    
    - The poll backend removes deleted events from the
      cached pollfd array now.
    
    - The poll doesn't pass pollfd.events == 0 to poll()
      and maintains a list of disabled events,
      instead of consuming 100% cpu and/or triggering
      the callers handler.
    
    - The poll backend detects POLLNVAL and reports EBADF
      instead of consuming 100% cpu.
    
    - The select backend supports separate handlers
      for TEVENT_FD_READ and TEVENT_FD_WRITE.
    
    - The poll and select backends are now doing fair
      queuing of fd events.
    
    - The epoll has better error checking
      and supports separate handlers
      for TEVENT_FD_READ and TEVENT_FD_WRITE.
    
    - The standard backend was rewritten to be a tiny
      wrapper on top of epoll with a fallback to poll,
      which means that it doesn't use select directly anymore.
    
    - TEVENT_TRACE_BEFORE_LOOP_ONCE and TEVENT_TRACE_AFTER_LOOP_ONCE
      are added in order to allow the application to hook in
      before and after the loop_once() backend function is called.
      The TEVENT_HAS_LOOP_ONCE_TRACE_POINTS define can be used to
      detect the new feature.