- Boost-users - lists.boost.org

Re: [Boost-users] [threads] extension proposal
by Oliver.Kowalke＠qimonda.com 08 Aug '06

08 Aug '06

> looks like what I need ;) The only question is, what does > stop() function of a defer_point? defer_pool::stop deactivates the threaded queue. All threads are awakened. > Will it stop all tasks > immediately or will it wait until the task queue is empty and > stop it then? It waits until all tasks were removed and processed from the queue. > Are there some plans to integrate this into the official > boost release? not yet > It would be nice to provide support for > different queue policies, like priority queue etc... May be > there are more wishes, like Vsevolod stated, by adding > support for threading or process policies... definetly - the library needs some improvements (fpr instance meber function defer should return a future). Oliver

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Re: [Boost-users] [threads] extension proposal
by Oliver.Kowalke＠qimonda.com 08 Aug '06

08 Aug '06

Hello Ovanes, please look into the boost vault (Concurrent Programming). I think the defer library fits your needs. The thread pool pre-spawns N threads which operate on a special queue (inside of the pool). If no task (boost::function objects) is queued all threads are set to sleep - if a task arives the queue one thread is awakened and fetches the task item from the queue and executes it (after that the thread goes to sleep again). The library was originally developed by Simon Meiklejohn. I've added the queue-stuff. regards, Oliver

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[program_options] Issues with boost::program_options freezing
by Zachary Mark 07 Aug '06

07 Aug '06

Hello, Our application is using boost::program_options to parse commandline arguments. We have found that when we perform our own builds of boost from source code, program_options freezes the application hard at variable points in the code (a step through in GDB confirms this). However, when we use pre-built binaries of the program_options library for any of our target OSes (Debian stable, Centos 4, Fedora 4) the application runs properly. We are also using the boost::thread library. Are there thread safety or interaction issues between thread and program_options that I am not aware of? We are using 1.32 due a change in the behavior of program_options in 1.33. This script shows how we are building boost. # run configure cd libs/config || fail-configure chmod +x configure || fail "error: could not change permissions on ${PACKAGE} configure script" ./configure || fail-configure cp user.hpp ../../boost/config/ cd ../.. # build and install libraries BOOST_LIBS="date_time filesystem program_options regex thread" for LIB in ${BOOST_LIBS}; do echo "Building library ${LIB}..." bjam -sTOOLS=gcc -sBUILD="release threading=multi" --with-${LIB} \ --layout="system" stage 2>&1 || \ fail "error: could not build boost library ${LIB}" bjam -sTOOLS=gcc -sBUILD="release threading=multi" --with-${LIB} --layout="system" \ --prefix=`pwd`/../../${INSTALL_DIR} install 2>&1 || \ fail "error: could not install boost library ${LIB}" done Thanks in advance. -- Zach

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Need help in serialization
by Anil Krishna 07 Aug '06

07 Aug '06

Hi All, Currently I am using the boost serialization library to serialize and the following structure: typedef list<int> testList; typedef testList::iterator lIter; typedef map<int, testList> testMap; typedef testMap::iterator tIter; testMap _tMap; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & _tMap; } int main() { test_map tm; ofstream ofs("map_details.txt"); tm.fillMap(); //tm.display(); boost::archive::binary_oarchive oa(ofs); oa << (const test_map)tm; ofs.close(); test_map newTm; ifstream ifs("map_details.txt", std::ios::binary); boost::archive::binary_iarchive ia(ifs); ia >> newTm; ifs.close(); newTm.display(); } In the above code, I am saving the map to a binary file and retrieving it from the file. Instead of that I would want to serialize the data into a char buffer and restore it from the buffer. This is useful for message communication, where I would like to send the map as a message from one process to another using socket communications. Can you any one let me know, how this can be done in boost? Regards, Anil

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Re: [Boost-users] Need help in serialization
by Todd Greer 07 Aug '06

07 Aug '06

Anil Krishna wrote: > In the above code, I am saving the map to a binary file and retrieving it > from the file. Instead of that I would want to serialize the data into a > char buffer and restore it from the buffer. Serialize into a std::ostringstream, ship its buffer to the other receiver, construct a std::istringstream from the received buffer, then deserialize from the istringstream you just constructed. Read up on std::istringstream and std::ostringstream (in <sstream>) for the details. BTW, if the sender and receiver are on different platforms, or you happen to need to send the data through something that has a problem with binary data, you can use text_[io]archive instead of binary_[io]archive. HTH, Todd Greer <tgreer <at> affinegy dot com> Senior Software Developer, Affinegy LLC

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shmem on multi-user machine
by Steven Wooding 07 Aug '06

07 Aug '06

Hi Ion, I've noticed that the "file" /dev/shmem/sem.boost_shmem_shm_global_mutex keeps hanging around after my program finishes. This file has write permission only for the user that created it. When different user comes along a runs another program that uses shmem, it seg faults on sem_wait(), probably due to the file permissions. Should this global mutex be cleaned up after use? Or could the permissions be changed somehow to let other use it (though probably not a good idea if user A and user B run a shmem based program at the same time). Thanks for your advice. Cheers, Steve.

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[Filesystem] Drive letter in argument for boost::filesystem::path
by Maarten Nieber 07 Aug '06

07 Aug '06

Dear boost users, can anybody explain how to pass a filename containing a (windows) drive letter into a boost::filesystem::path? For instance, if the path should point to c:\test.txt (on a Windows system), what is the portable filename that I should pass to the boost::filesystem::path constructor? Thanks in advance! Maarten __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Portability of boost libs for "universal linux binary?"
by Zachary Mark 07 Aug '06

07 Aug '06

Details: I work on a project where one of the eventual goals is to have one binary for a given architecture that runs on multiple Linux distributions. This goal is currently accomplished by both Sun's Java VM as well as the cmake project ( http://www.cmake.org/HTML/Index.html ). We are in the process of evaluating how this goal is impacted by third party dependencies. We currently use the following boost libs: thread, program_options, regex, date_time, and filesystem. I strongly suspect that the thread lib is going to be the biggest cause of grief towards accomplishing this goal (mostly due to the inability to static link it). Are the other (non thread) boost libs statically linkable? Thanks in advance. -- Zach

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zlib memory leaks [RC_1_34_0]
by Thomas Pintaric 06 Aug '06

06 Aug '06

I noticed that /boost/boost/iostreams/filter/zlib.hpp (Revision 1.25.2.1) from the RC_1_33_0 branch, for which the zlib memory leaks were fixed, still needs to be merged with the MAIN branch.

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boost-python Newbie tutorial needed.
by chun ping wang 06 Aug '06

06 Aug '06

Hmm k i have a simple question, how would I build boost.python given this following information. I am using dev-cpp and its install in "c:\dev-cpp" folder. IN it contains the mingw32 sub directory My project folder is "c:\cs classes\cs386\c++". In it contains FiniteAutomta.cpp which maps to python module... my boost folder is "C:\boost_1_33_1" in it contains the bjam.exe file. PYTHON_ROOT = "C:\python24" Thanks for the help. I look at the tutorial but is confused on how I can build my project.

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