September 2008 - Boost - lists.preview.boost.org

Boost c++ language conformance
by Sean Farrow 18 Sep '08

18 Sep '08

Hi: What advanced features of c++ does boost use, I'm thinking features that can cause problems with different c++ compilers. I'm evaluating the boost trunk with codegear c++ 2009, and would like to know what to look out for! What is the best compiler for standard complience on win32? Cheers Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 3443 (20080915) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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[test] Bug in /boost/test/impl/execution_monitor.ipp
by Boris 18 Sep '08

18 Sep '08

The SIGCHLD case (line 404 to 437) in file boost/test/impl/execution_monitor.ipp confuses the pid and uid (see http://www.boost.org/doc/libs/1_36_0/boost/test/impl/execution_monitor.ipp for a quick check). Is this the right place to report the bug? Boris

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[filesystem] 1.36.0 regression tests fail on Solaris with Sun C++ 5.9
by Boris 18 Sep '08

18 Sep '08

When I run the regression tests for Boost.Filesystem on Solaris with Sun C++ 5.9 I get this error: sun.compile.c++ ../../../bin.v2/libs/filesystem/build/sun/debug/link-static/operations.o "../../../libs/filesystem/src/operations.cpp", line 1060: Error: Cannot use std::pair<boost::system::error_code, int> to initialize std::pair<boost::system::error_code, unsigned long long>. "../../../libs/filesystem/src/operations.cpp", line 1062: Error: Cannot use std::pair<boost::system::error_code, int> to initialize std::pair<boost::system::error_code, unsigned long long>. "../../../libs/filesystem/src/operations.cpp", line 1096: Error: Cannot use std::pair<boost::system::error_code, int> to initialize std::pair<boost::system::error_code, long>. 3 Error(s) detected. "CC" +d -g -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_STATIC_LINK=1 -I"../../.." -c -o "../../../bin.v2/libs/filesystem/build/sun/debug/link-static/operations.o" "../../../libs/filesystem/src/operations.cpp" Is this a known problem? Boris

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outdated status\expected_results.xml
by joaquin＠tid.es 18 Sep '08

18 Sep '08

This file has not been updated since 08/12/07: http://tinyurl.com/48p38y which suggests it contains the expected results for Boost 1.34.1. So, Boost 1.36 tests are and 1.37 tests will be comparing against an outdated file (each version should compare against the former). There doesn't seem to be any documentation on Boost about how to do the updating, and the file is not even mentioned at the release manager's checklist at http://svn.boost.org/trac/boost/wiki/ReleasePractices/ManagerCheckList Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Which version?
by Robert Jones 18 Sep '08

18 Sep '08

I've found a boost distribution in the build at work. How can I determine which release it is? - Rob.

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[msvc] disable 64-bit warning
by Jürgen Hunold 18 Sep '08

18 Sep '08

Hi ! When compiling Boost with address-model=64, some libraries issue msvc-warning BOOST_ROOT\boost/config/abi_prefix.hpp(19) : warning C4103: 'BOOST_ROOT\boost\config\abi_prefix.hpp' : alignment changed after including header, may be due to missing #pragma pack(pop) See msvc_9_4103.txt for a full dump using bjam -a -q address-mode=64 -WX Those libraries are: - system - filesystem - serialization - wave Please find the necessary patches attached. Additionaly, I've added _SCL_SECURE_NO_WARNINGS to serialization and changed wave to always set _SCL_SECURE_NO_DEPRECATE and _CRT_SECURE_NO_DEPRECATE regardless of the compiler version. This should silence those warning for the msvc incarnation, too. Okay to commit ? Comments ? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold(a)ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !

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Unused Parameter Warnings
by Michael Marcin 18 Sep '08

18 Sep '08

I'm trying to silence a lot of unused parameter warnings in the boost 1.36 libraries I'm using. I'd like to submit these as patches so I don't have to fix them again (I've had to do it for 1.34 and 1.35). Is there a preferred boost wide solution to silencing these warnings? Should I consult each library author on their preference? AFAIK there are 4 common ways to silence these warnings. * Compiler specific pragmas * Pass by const reference to an empty inline template function * Cast to void * Delete the parameter name * C-style comment out the parameter name -- Michael Marcin

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boost::filesystem: leaf() missing?
by Robert Dailey 17 Sep '08

17 Sep '08

Hi, I noticed I cannot use the leaf() function off of boost::filesystem::path anymore in 1.36. The documentation examples are still using leaf(). Is this broken?

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[threadpool]thread management strategies
by vicente.botet 17 Sep '08

17 Sep '08

Hi, I have do a comparaison of the three thread management strategies fixed, lazy and adaptive header files and I found some incoherences that are possible bugs. * In fixed.hpp and lazy.hpp the size_ function should be const std::size_t size_() { return worker_.size(); } * In lazy.hpp submit_ is not used channel_iterator submit_( channel_item const& itm) { return channel_.put( itm); } * In adaptive and lazy add the assertion on constructor BOOST_ASSERT( lwm <= hwm); * In adaptive void core_size( std::size_t size) { shared_lock< shared_mutex > lk( mtx_worker_); core_size_ = size; } must use a unique_lock instead of a shared_lock * In lazy std::size_t max_size() { return max_size_; } should't have a shared_lock guard. The three files have more in common than differences. Doesn't the following pools behaves identically boost::tp::pool< boost::tp::fixed, boost::tp::unbounded_channel< boost::tp::fifo > > pool( boost::tp::max_poolsize( 10) ); boost::tp::pool< boost::tp::lazy< depend_on_core >, boost::tp::unbounded_channel< boost::tp::fifo > > pool( boost::tp::preallocate( 10), boost::tp::core_poolsize( 10), boost::tp::max_poolsize( 10) ); boost::tp::pool< boost::tp::adaptive< depend_on_core, keep_core_size >, boost::tp::unbounded_channel< boost::tp::fifo > > pool( boost::tp::preallocate( 10), boost::tp::core_poolsize( 10), boost::tp::max_poolsize( 10), boost::posix_time::very_high ); Looking at the differences we have the following feature model PoolSize: fixed|variable[AdjustmentPolicy, ShrinkPolicy] ShrinkPolicy: no_shrink | shrink [RecreatePolicy] I was wondering if we can define a class thread_management taking a feature expression and use it as follows thread_management<fixed> to mean the current fixed thread_management<variable<AdjustmentPolicy> > to mean the current lazy<AdjustmentPolicy> thread_management<variable<AdjustmentPolicy, shrink<RecreatePolicy> > > The advantage of this approach is that we avoid the incoherences. The liability is that this class must use metaprogramming in its implementation to preserv the efficiency. What do you think? Vicente

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[threadpool] remarques to the documentation
by vicente.botet 17 Sep '08

17 Sep '08

Hi, I'm reading the documentation and I don't find any description of the concepts Strategy, Channel, QueueingPolicy, Callable. Do you plan to describe explicitly these concepts in the documentation ? What do you think about adding a Worker concept, and adding it as parameter to the Strategy template class? I think that the tutorial must be reworked, including more practical examples, and starting from the most basic use and going on each one of the use cases where the different features are better adapted, currently it seams more to a informal reference manual. Some naming suggestions: * ThreadManagementStrategy sould be a better name for Strategy. * As QueueingPolicy can be either fifo or lifo, SchedulingPolicy sould be more apropiated. * Pending tasks can be more adecuated than queued tasks. You can use take instead of dequeue which is more general. Could you give a use case for lifo order? What about a manual thread management strategy, allowing the user to add new workers or interrupting them? A copy/paste: In the fixed example there is a reference to tp::channel which should be tp::bounded_channel. In the lazy example // creates a lazy pool with unbounded channel // tasks are processed in FIFO order // the pool contains ten worker threads // no worker threads are started at construction boost::tp::pool< boost::tp::lazy< depend_on_core >, boost::tp::unbounded_channel< boost::tp::fifo > > pool( boost::tp::core_poolsize( 5) boost::tp::max_poolsize( 10) ); Can this pool have more than 5 worker threads? If the worker threads are created "if current poolsize size is less than core_poolsize or the channel is full", as the channel is unbounded_channel the channel will never be full, so when the current poolsize size will be 5 no new threads will be created, ins't it? the adaptive ThreadManagementStrategy seems to be in contradiction to the goal of the threadpool "Using a thread pool over creating a new thread for each task may result in better performance and better system stability because the overhead for thread creation and destruction is negated." Could you present a use case in which this adaptive strategy could be useful? In channnel section you say "If the channel becomes empty all worker threads are set to sleep until a new task is enqueued." Except for the adaptive strategy which has a keep_alive timeout, the other waits until a new task is submited, isn't it? Which are the advantages/liabilities of a bounded channel respect to an unbounded one? When it is better to use one of them? It will be great to have an example justifying the need for the rendezvous channel. A copy/paste: In the smart section smart must replace priority template< typename Attr, typename Ord, typename Enq, typename Deq > struct priority A typo: replace terminateing by terminating in docs and in code Best regrads, Vicente

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