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How to implement a reader-writer lock with quick response to writer?
by Bill David 19 Sep '08

19 Sep '08

Question: How to implement a reader-writer lock with quick response to writer? I am using boost1.35.0.( I know 1.36.0 is available, but I failed to build regex in 1.36.0 with VC8. Have you also met this problem in your environment?) I have the following requirements: 1.There are several reader threads and a single writer thread. The writer thread will update shared data periodically. And reader threads may read shared data at any time. 2.As long as writer thread try to update data, all reader thread should be blocked as soon as possible. 3.And reader thread should be blocked during data updating. 4.But reader threads can't be interrupted when they are reading. (i.e. all upcoming reader threads should be blocked, but writer still need wait till the last reader thread in reading finished.) How to implement above scenario with quick response to writer thread? I tried to write the following program to test shared_mutex, but it seems it can't meet my requirement: #include <iostream> using namespace std; #include <boost/thread/shared_mutex.hpp> #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> using namespace boost; boost::shared_mutex rw_mutex; int g_i = 1; void sleep(int iSec) { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += iSec; boost::thread::sleep(xt); } void read() { while (true) { rw_mutex.lock_shared(); cout << g_i << endl; sleep(3); rw_mutex.unlock_shared(); } } int main() { boost::thread_group threads; for (int i = 0; i < 3; i++) threads.create_thread(read); sleep(1); rw_mutex.lock(); cout << "lock" << endl; g_i = 2; cout << "update g_i to " << g_i << endl; sleep(5); cout << "unlock" << endl; rw_mutex.unlock(); threads.join_all(); } The problem to above solution is it can't respond to writer thread as soon as possible, and only in rare case, it can respond to writer thread in about 6 seconds. The following is a possible output I have gotten: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 lock update g_i to 2 unlock 222 2 2 2 The writer thread should wait no more than 6 seconds, but it seems it can wait more than 20 seconds. Can shared_mutex meet such kind of scenario? If not, do you have any other suggestion?

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multidimensional interval library?
by Roland Schwarz 19 Sep '08

19 Sep '08

Is there a straight forward way to use the interval library for multi dimensions? Specifically I want to express 3d boxes and want to test for intersection and the like. -- _________________________________________ _ _ | Roland Schwarz |_)(_ | aka. speedsnail | \__) | mailto:roland.schwarz@chello.at ________| http://www.blackspace.at

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Is there a parameter to build without compiler version info in the target library name?
by Bill David 19 Sep '08

19 Sep '08

By default, the compiled library have a name like: libboost_thread-gcc41-mt.a but I don't want the gcc41 information in the name as I may need modify my makefile to switch to another environment with gcc4.3. So is there a parameter in bjam to suppress the compiler version info in target library name? Or how will you solve this kind of problem?

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<boost/numeric/ublas/matrix.hpp> includes <iostream>. Is it better not to do so?
by Peng Yu 19 Sep '08

19 Sep '08

Hi, It seems that <boost/numeric/ublas/matrix.hpp> includes <iostream>. I remember that it is better not to include <iostream> but something like <ostream> and <istream>, or even simply <iosfwd>. I'm wondering if this issue shall be corrected in the future version of ublas. Thanks, Peng #include <boost/numeric/ublas/matrix.hpp> int main () { std::cout << "Hello" << std::endl; }

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How to submit a package to boost? (solving quartic, cubic and quadratic equations)
by Peng Yu 18 Sep '08

18 Sep '08

Hi, I made a small utility package that solves quartic, cubic and quadratic equations analytically. It give the multiplicity of the roots and tells whether the roots are zero, no-zero real or non real. I think it is appropriate to submit the package to boost. It might fits the following utility http://www.boost.org/doc/libs/1_35_0/libs/math/doc/sf_and_dist/html/math_to… I'm wondering how to submit my package to boost. Thanks, Peng

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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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