[mythtv-commits] Ticket #6330: [RFC] New ThreadedFileWriter (lockless)

[MythTV]

#6330: [RFC] New ThreadedFileWriter (lockless)
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 Reporter:  Matthias "mortalmatt" Dahl <devel at mortal-soul.de  |        Owner:  ijr 
     Type:  enhancement                                       |       Status:  new 
 Priority:  minor                                             |    Milestone:  0.22
Component:  MythTV - General                                  |      Version:  head
 Severity:  medium                                            |   Resolution:      
  Mlocked:  0                                                 |  
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Comment(by Matthias "mortalmatt" Dahl <devel at mortal-soul.de>):

 Paul, the old code base is better tested on a wider range of platforms. I
 have only been able to test this very thoroughly on a x86_64 based machine
 which ironically uncovered a corruption bug with the old TFW.

 The lockless TFW relies on the atomic operations support of Qt which is
 not supported natively on all platforms, meaning that they are emulated
 with e.g. mutexes. Even though I doubt PA-RISC, SH or Blackfin matter for
 MythTV, so that shouldn't be a problem.

 On PowerPC, S390, MIPS and SH-4a, the atomic operations are supported
 natively but are not guaranteed to be wait free. I haven't been able to
 test on those systems, so I can't say how much that affects performance.
 Based on some research I did and some talking on the Qt irc channel, that
 won't be a problem too performance wise but I still would like to see some
 profiling data (old TFW vs. lockless TFW) for those systems, if they
 matter for MythTV... I guess PowerPC still does?

 That's all that jumps to my mind actually. Like I initially said, I trust
 it enough to use it myself. :-)

-- 
Ticket URL: <http://svn.mythtv.org/trac/ticket/6330#comment:12>
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