Re: [Boost-bugs] [Boost C++ Libraries] #3690: regex depends on pthread library when boost is built with threading=single

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3690: regex depends on pthread library when boost is built with threading=single
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-12-03 16:39:05

#3690: regex depends on pthread library when boost is built with threading=single
---------------------------------+------------------------------------------
 Reporter:  jdccdevel@…          |       Owner:  vladimir_prus
     Type:  Bugs                 |      Status:  new          
Milestone:  Boost 1.42.0         |   Component:  build        
  Version:  Boost 1.40.0         |    Severity:  Problem      
 Keywords:                       |  
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Changes (by johnmaddock):

  * owner:  johnmaddock => vladimir_prus
  * component:  regex => build

Comment:

 I'm reassigning this because it's a Boost.Build issue, but... it might not
 be an issue at all:

 As I recall after a long and agonising discussion, Boost.Build and
 Boost.Config were changed so that:

 * threading=multi: changes whatever needs changing to make multithreaded
 builds work.
 * threading=single: actually just uses the compiler's default options, if
 those happen to be thread-safe (ie the same as used for threading=multi)
 then BOOST_HAS_THREADS gets defined, and regex will use pthreads.

 The rationale for this change was that most people actually want "one true
 binary" rather than a multitude of threadsafe / not threadsafe options.
 So on many platforms threading=multi and threading=single actually deliver
 the same thing.  [aside - it would actually have been better IMO to have
 had 3 options - threading=multi, threading=default, and threading=single]

 There is one other option, which is to build with BOOST_DISABLE_THREADS
 defined, which really will build a thread-unsafe binary - and of course
 that define would have to be set when you compile your source code as
 well.

 I notice you don't mention which compiler you are using?  Can you confirm
 whether there is any material differnce between how your compiler behaves
 with and without whatever command-line options are enabled by
 threading=multi (try building with bjam -d2 to see what options are being
 used)?

 HTH, John.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3690#comment:1>
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