March 2004 - Boost-users - lists.preview.boost.org

boost::thread and std::system
by Jerry Swan 10 Mar '04

10 Mar '04

I'd like to be able to issue a call to std::system that will time-out after a specified period. Is it possible to achieve this using the boost::threads library? If so could someone kindly sketch how this might be achieved? TIA, Jerry.

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python library issue migrating from boost_1_30_2 to boost_1_31_0
by Marco Donizelli 09 Mar '04

09 Mar '04

Hi there, when I built the 1_30_2 Python Library, I got: libboost_python.so now, with 1_31_0, I get several libs but that one: libboost_python-gcc-1_31.a libboost_python-gcc-1_31.so libboost_python-gcc-1_31.so.1.31.0 libboost_python-gcc.a libboost_python-gcc-d-1_31.a libboost_python-gcc-d-1_31.so libboost_python-gcc-d-1_31.so.1.31.0 libboost_python-gcc-d.a libboost_python-gcc-d.so libboost_python-gcc-mt-1_31.a libboost_python-gcc-mt-1_31.so libboost_python-gcc-mt-1_31.so.1.31.0 libboost_python-gcc-mt.a libboost_python-gcc-mt-d-1_31.a libboost_python-gcc-mt-d-1_31.so libboost_python-gcc-mt-d-1_31.so.1.31.0 libboost_python-gcc-mt-d.a libboost_python-gcc-mt-d.so libboost_python-gcc-mt.so libboost_python-gcc.so Unless I made a mistake in the building step which prevented libboost_python.so to be created, the first solution that comes to my mind to solve this backward compatibility problem would be to create a symlink from libboost_python.so to one of the new libraries. The question is, what would you recommend: libboost_python-gcc.so or libboost_python-gcc-mt.so (or none of the above, but....) thanks a million marco

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RE: [Boost-users] Re: install? and simple thread program.
by Duong, Sanh N. 08 Mar '04

08 Mar '04

I downloaded the latest version of Python from the website given below and ran it with "rpm --rebuild python2-2.2-2.src.rpm." Python seems to install correctly. I reset my env variables to PYTHON_ROOT=/usr and PYTHON_VERSION=2.2. Yet when I ran bjam, it would say it couldn't find the Python.h file within /usr/include/python2.2/. The directory is there, but its empty. There is an another directory for python1.5. But this version will not compile Boost correctly. Any suggestions or idea of why this is happening? Thanks. Sanh. -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of David Abrahams Sent: Monday, March 08, 2004 1:53 PM To: boost-users(a)lists.boost.org Subject: [Boost-users] Re: install? and simple thread program. "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> writes: >> On Fri, 5 Mar 2004, Michael Glassford wrote: >> >>> "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> wrote in message >>> >> The Boost.Python example should still work just fine, if you follow >> the instructions. bjam doesn't use the mangled library names when >> building with cross-project dependencies. It worked for me just >> now. I went into libs/python/example and did > >> bjam test > >> and everything passed. No funky linking should is needed. > > When running bjam test, in libs/python/example I'd get a lot of errors about > templates and vars not define. Let's see a few of them. > Another thing I noticed, when installing > boost with > > bjam "-sGXX=g++" "-sTOOLS=gcc" "--prefix=/home/boost_1_31_0" install > > it would say, "Skipping Boost.Python library build due to missing or > incorrect configuration couldn't find Python.h in "/include/python" Right. > When I point the PYTHON_ROOT and PYTHON_VERSION to the correct path, I'd get > a lot of errors when compiling. Is there a step I'm missing here? Hard to say without seeing the errors. My guess is that you didn't set them correctly. Did you follow the directions at http://www.boost.org/libs/python/doc/building.html ?? -- Dave Abrahams Boost Consulting www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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RE: [Boost-users] Re: install? and simple thread program.
by Duong, Sanh N. 08 Mar '04

08 Mar '04

> On Fri, 5 Mar 2004, Michael Glassford wrote: > >> "Duong, Sanh N." <SANH.N.DUONG(a)saic.com> wrote in message >> news:6A47CB4A48D1EA49A6F7AB618490D649069D8C3C@mcl-its-exs03.mail.saic.com... >> > All, >> > >> > Does anyone have an example of how to install boost and bjam? >> >> See the recently much improved Getting Started guide: >> http://boost.org/more/getting_started.html. > > After you follow those instructions, boost will still not work. > Even if you were right, I think you're painting with too broad a > brush here. But I think you're wrong. > You'll need to create links to all of the mangled library names. For > example, in my case all of the libraries have either "gcc" or > "gcc_1_31" mangled in. However, the examples (or more specifically > the boost.python example) assume that the libraries have unmangled > names. > The Boost.Python example should still work just fine, if you follow > the instructions. bjam doesn't use the mangled library names when > building with cross-project dependencies. It worked for me just > now. I went into libs/python/example and did > bjam test > and everything passed. No funky linking should is needed. When running bjam test, in libs/python/example I'd get a lot of errors about templates and vars not define. Another thing I noticed, when installing boost with bjam "-sGXX=g++" "-sTOOLS=gcc" "--prefix=/home/boost_1_31_0" install it would say, "Skipping Boost.Python library build due to missing or incorrect configuration couldn't find Python.h in "/include/python" When I point the PYTHON_ROOT and PYTHON_VERSION to the correct path, I'd get a lot of errors when compiling. Is there a step I'm missing here? Sanh.

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Compiler Generator Tools
by Hossein Haeri 08 Mar '04

08 Mar '04

Dear all, Who knows where I can find the compiler generation stuff in the Boost repository? I need scaner, lexical analyser, compiler, code generator, ... Are there any such tools in the Boost which can build all of the above goodies for me? TIA, --Hossein __________________________________ Do you Yahoo!? Yahoo! Search - Find what you�re looking for faster http://search.yahoo.com

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Mac OS X link problem
by Adam H. Pendleton 07 Mar '04

07 Mar '04

I am using the Boost libraries, specifically the Spirit portions, on Mac OS X Panther, using XCode. Every time I try to compile my program with the Boost libraries I get a linker error: ld: warning prebinding disabled because of undefined symbols ld: Undefined symbols: boost::throw_exception(std::exception const&) Even if I link against all the boost libraries that were created, I still can't get this program to link. The documentation talks about the libraries being compiled with or without BOOST_NO_EXCEPTIONS, but they don't indicate that the program won't link in either case. What am I doing wrong? ahp

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Boost Users: Review Schedule/Upcoming Reviews
by Jeff Garland 06 Mar '04

06 Mar '04

Below is the most recent updates to the reviews. If you have an interest in these libraries please get involved and submit a review. Library Author Review Mgr Dates Circular Buffer Jan Gaspar Pavel Vozenilek 2004 Mar 5-15 Indexed Set Joaquín M López Muñoz Pavel Vozenilek 2004 Mar 20-30 Assignment Thorsten Ottosen Tom Brinkman 2004 Apr 1-11 Serialization Robert Ramey Jeff Garland 2004 Apr 13-20 Container Traits Thorsten Ottosen Hartmut Kaiser 2004 Apr 28-May 7 Tribool Douglas Gregor - - More IO Daryle Walker - - Iostreams Jonathan Turkanis - - Output Formatters Reece Dunn - - Pointer Containers Thorsten Ottosen - - Named Params David Abrahams & Daniel Wallin - - Wave Hartmut Kaiser - -

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Changing case with regex_format
by Keith MacDonald 06 Mar '04

06 Mar '04

The following useful Perl expressions seem to have been omitted from regex_format: \l lowercase next char \u uppercase next char \L lowercase till \E \U uppercase till \E \E end case modification Was there a good reason for that? The only way I can see to implement those expressions is to take a copy of regex_format.hpp, then hack _reg_format_aux. I think that it would also be necessary to change the undocumented regex_traits class, to do upper case conversion, as it only seems to do lower casing at present. Is there an easier way? Thanks, Keith MacDonald

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install? and simple thread program.
by Duong, Sanh N. 06 Mar '04

06 Mar '04

All, Does anyone have an example of how to install boost and bjam? Does someone also have a simple program using boost and threads. Thanks in advance, Sanh

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Futures revisited
by Slawomir Lisznianski 05 Mar '04

05 Mar '04

Hello, During discussions on possible extensions to Boost.Threads, concept of Futures came up rather frequently. Below, I’d like to introduce a particular implementation available at www.rhapsodia.org of which requirements were defined as follows: 1. Provide means to register exception types with a "Future Registry". Rationale: I find it imperative that users should not have to define a list of exception types on each invocation yielding a Future object. Instead, provide the ability to register exception types with a Future Registry and bundle it with Future objects. I feel that compile time registration should be sufficient. 2. Work under the assumption that asynchronous invocations returning Futures and system threads are not coupled. In particular, Futures implementation should not relay on joining with a particular thread to perform synchronization for returning results. Rationale: Although most prevalent, the technique of joining with a particular thread to synchronize on returning result is too limiting. It implies that each task be run on a dedicated thread, specially created to handle it and destroyed to meet with a caller using a Future. Although this approach may be adequate under certain conditions, it generally tends to be expensive on system resources and disorganizes the application. For example, it’s impossible to control the number of concurrently running threads. It may also perform poorly if executed code happens to run shortly as the overhead of creating a thread and cleaning up after it may be significant. More robust approach is to use a queue and a thread pool for running tasks. This adds complexity on the synchronization side, as we can no longer rely on a lifetime of a thread to join with Future’s result. 3. Ability to utilize Futures with arbitrary code without explicit support for them. Rationale: For implementation to be widely adopted, it should be possible to turn just about any function call into a Future-armored asynchronous invocation. No explicit thread synchronization primitives should be used as well. 4. Implement using existing Boost.Threads facilities only. Rationale: Boost.Threads library provides enough support to implement Futures paradigm that meets requirements listed here. 5. STL and Boost compatible. For example, storing Futures in an STL container. Be strongly typed. Futures implementation and usage patterns must naturally coexist with STL and Boost code. Additionally, compile-time type validation is key to safer code. Attached is a sample file from Rhapsodia library showing the use of Futures. Regareds, Slawomir Lisznianski [ www.rhapsodia.org ]

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