June 2002 - Boost-users - lists.preview.boost.org

thread::join() usage
by rgalek2002 10 Jun '02

10 Jun '02

Hi, I have an application which starts a number of threads, and I want the application to wait for the threads to finish before exiting. Standard stuff, I know, but never having used threads before I am wondering what the stadard way is to accomplish this. I have (psuedo code) for (each record in database) { thread thrd(func(), data); } I could imagine storing all my thread objects in a list, and then calling join() on each one. For example something like list <thread> threads; for (each rec in db) { thread thrd(func(), data); threads.insert(threads.begin(),thrd); } list<thread>::iterator i; for (i=threads.begin(); i!=threads.end(); i++) { thread t = *i; t.join(); } Does this seem reasonable? Is there a better/standard way? One thing I don't like here is that each join will block, when what I would like to do is something more like join_all(); Thanks, Rich

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Intel-win32 Build Problem
by thorneg 09 Jun '02

09 Jun '02

I'm getting errors in xtime.cpp relating to uint64_t when building with the Intel-win32 v6.0 compiler. The errors are: xtime.cpp libs\thread\build\../src\xtime.cpp(80): error: namespace "boost" has no member "uint64_t" const boost::uint64_t TIMESPEC_TO_FILETIME_OFFSET = ((boost::uint64_t)27111902UL << 32) + (boost::uint64_t)3577643008UL; Has anyone else run into this? Any help is appreciated. Glenn

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Dynamic Bitset Formal Review June 8-17
by Mat Marcus 08 Jun '02

08 Jun '02

The formal review of Dynamic Bitset by Chuck Alison and Jeremy Siek will commence today Saturday June 8th and run through Monday, June 17th. The library is currently available at <http://groups.yahoo.com/group/boost/files/dyn_bitset.tar.gz> Below is an excerpt from the library's documentation: The dyn_bitset class represents a set of bits. It provides accesses to the value of individual bits via an operator[] and provides all of the bitwise operators that one can apply to builtin integers, such as operator&& and operator<<. The number of bits in the set is specified at runtime via a parameter to the constructor of the dyn_bitset. Each bit represents either the Boolean value true (set) or false (reset). To toggle a bit is to change the value to true if it is false and to false if it is true. Each bit has a non-negative position pos. The position pos == 0 corresponds to the least significant bit and pos == size() - 1 is the most significant bit. When converting an instance of dyn_bitset to or from an unsigned long, the bit position pos corresponds to the bit value 1 << pos. The dyn_bitset class is nearly identical to the std::bitset class. The difference is that the size of the dyn_bitset (the number of bits) is specified at run-time during the construction of a dyn_bitset object, whereas the size of a std::bitset is specified at compile-time through an integer template parameter. For information about submitting a Formal Review, see http://www.boost.org/more/formal_review_process.htm Please try out the library and comment during the review period. Be sure to say whether or not you think the library should be accepted by Boost. Compiler notes: This library has been tested using the following compiler platforms: Gcc 2.95 and 3.01 Kai C++ Metrowerks Codewarrior 8 (beta, Mac) Visual C++ 7.0 Comeau The library presently requires template friend support and is known not to compile with CodeWarrior 7.2 or Visual C++ 6.0. The library has not been tested with Borland. The Formal Review manager is Mat Marcus.

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MacOS.hpp and PowerPlant incompatibility
by Bobby Thomale 08 Jun '02

08 Jun '02

I am trying to use the boost libraries with a PowerPlant project on the MacOS, and I ran into a small incompatibility between the headers. I am not sure which codebase is at fault here. The issue is with the __MACH__ symbol. In the Boost code where it is checking for what platform I am using, it correctly identifies my platform as MacOS. Then, in a file called MacOS.hpp, it uses the __MACH__ symbol to determine if I am using the BSD standard C libraries or MSL. (I am using MSL.) It does this by checking for the EXISTANCE of the __MACH__ symbol, not the value of it: // If __MACH__, we're using the BSD standard C library, not the MSL: #if defined(__MACH__) However, in the PowerPlant header PP_Macros.h, the __MACH__ symbol is defined and set to zero: #ifndef __dest_os // For MSL #ifndef __MACH__ #define __MACH__ 0 #endif #if __MACH__ #include <ansi_prefix.mach.h> #else #define __dest_os __mac_os #endif #endif I was able to work around the problem for now by making the Boost libraries check for both the existance of __MACH__ and the value: #if defined(__MACH__) && __MACH__ Seems to work. However, I am curious. Which way is the right way? Is the __MACH__ symbol's existance or its value supposed to signal whether or not it is "turned on"? The boost headers seem to think it is its existance, but the PowerPlant headers seem to think it is its value. I want to report the problem, but I am not sure whose code needs to change, PowerPlant or Boost. Ideas? -- Bobby --------------------------------------------------------------------- Bobby Thomale Senior Software Developer Inoveon Corporation http://www.inoveon.com/ ---------------------------------------------------------------------

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[BGL] How can I use vertex object rather than integer?
by �ڱ�� 07 Jun '02

07 Jun '02

for example, class Node { public: int m_id; }; class Edge { public: int from_node_id; int to_node_id; }; How can I use this class to make graph? many examples show only integer id graph.. thanks in advance ---------------------------------------- Ki-Soo, Park HP: 82-11-9040-4957 e-mail: park(a)erhouse.co.kr wfms123(a)hotmail.com

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[BGL] how to use visitor with functor?
by �ڱ�� 06 Jun '02

06 Jun '02

Can I use visitor with functor ? In BGL example on visitor, int main() { : boost::breadth_first_search (G, vertex(0, G), visitor(make_bfs_visitor( std::make_pair(print_edge("tree", on_tree_edge()), print_edge("cycle", on_non_tree_edge()))))); : } I want to do like this boost::breadth_first_search (G, vertex(0, G), visitor(make_bfs_visitor( std::make_pair(print_edge("tree", on_tree_edge(), MyFunctor1() ), print_edge("cycle", on_non_tree_edge(), MyFunction2() ))))); can i do this? how? why? thanks in advance.. ps. ths is my first posting. ---------------------------------------- Ki-Soo, Park e-mail: park(a)erhouse.co.kr wfms123(a)hotmail.com

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Boost::Python constructor overloading problems
by John Hunter 06 Jun '02

06 Jun '02

I have been using boost python for some time now and recently upgraded to boost_1_28_0 and gcc 3.0.4. I started getting a segmentation fault when using a library with an overloaded constructor. In trying to track down the source of the problem, I wrote a simple class with an overloaded constructor and still get the seg fault. Perhaps there is something wrong with code or the compile statement, but I have been unable to find. it. So I've also included some additional info below that may give someone a clue as to what is going wrong. Here is the python script which calls the simple class. The second constructor crashes with a seg fault: from TestSimple import Simple # Default constructor OK d1 = Simple() print d1.get() i = 1 d2 = Simple(i) # this line causes the seg fault print d2.get() ---- Here is the code I use to make the module TestSimple: #include <boost/python/class_builder.hpp> class SimpleClass { public: SimpleClass() : i(-1) {}; SimpleClass(int i) : i(i) {}; int get() const { return i; } private: const int i; }; namespace python = boost::python; BOOST_PYTHON_MODULE_INIT(TestSimple) { python::module_builder m( "TestSimple" ); python::class_builder<SimpleClass> simple(m, "Simple"); simple.def(python::constructor<>()); simple.def(python::constructor<int>()); simple.def(&SimpleClass::get, "get"); } ---- Here are the compile commands: /usr/local/bin/g++ -I/usr/local/include/python2.1 -I/usr/local/include -ggdb -Wall -fPIC -ftemplate-depth-21 -c TestSimplePy.cpp /usr/local/bin/g++ -shared -L/usr/local/lib -ggdb -Wall -fPIC -ftemplate-depth-21 TestSimplePy.o -o TestSimple.so -lboost_python ---- I run the script in a controlled environment with: #!/bin/sh export LD_LIBRARY_PATH=/usr/local/lib /usr/local/bin/python2.1 ./testSimple.py ---- Here is the ldd for the TestSimple module: mother:~/c/trade/test> ldd TestSimple.so libboost_python.so.1.28.0 => /usr/local/lib/libboost_python.so.1.28.0 (0x40011000) libstdc++.so.3 => /usr/local/lib/libstdc++.so.3 (0x40078000) libm.so.6 => /lib/i686/libm.so.6 (0x40112000) libgcc_s.so.1 => /usr/local/lib/libgcc_s.so.1 (0x40136000) libc.so.6 => /lib/i686/libc.so.6 (0x4013e000) libutil.so.1 => /lib/libutil.so.1 (0x4026e000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000) ---- All the version info looks right -- python2.1 was compiled with the same gcc (3.0.4) that the module was. Thanks for any suggestions, John Hunter

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CW project file
by NOEL Bruno 06 Jun '02

06 Jun '02

Hello, As I am much more familiar with the Metrowerks IDE than with standard makefiles, has anyone made a .mcp project file able to compile whole of the boost library with Codewarrior ? Thanks for the answers and possible files ! Bruno NOËL

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Re: problem with c_regex_traits.cpp
by René Gutschmidt 06 Jun '02

06 Jun '02

>> i have problems with the file c_regex_traits.cpp. I work under CodeWarrior >> 6/7 with a Macintosh. >> These problem ist with boost 1.25.1,1.26. >> >> template <class charT> >> unsigned int BOOST_REGEX_CALL re_get_message(charT* buf, unsigned int >> len, unsigned int id) >> { >> unsigned int size = _re_get_message((char*)0, 0, id); >> if(len < size) >> return size; >> boost::scoped_array<char> cb(new char[size]); >> _re_get_message(cb.get(), size, id); >> size = boost::c_regex_traits<wchar_t>::strwiden(buf, len, cb.get()); >> return size; >> } >> >> inline unsigned int BOOST_REGEX_CALL re_get_message(char* buf, unsigned >> int len, unsigned int id) >> { >> return _re_get_message(buf, len, id); >> } >> >> Is that a known problem? Do you know a workaround? >> (Renaming one of the 're_get_message()' functions does >> the job, but I'm not sure about the implications.) > > I've had a chance to experiment a little with this - if BOOST_NO_WREGEX is > defined (i.e. wide character support is disabled), then removing the > template version of re_get_message is harmless (and may therefore be the fix > that you are looking for). If BOOST_NO_WREGEX is not defined, then > obviously this won't work - so that being the case, what happens if you > surround the definition of > > template <class charT> > unsigned int BOOST_REGEX_CALL re_get_message(charT* buf, unsigned int len, > unsigned int id) > > with > > #ifndef BOOST_NO_WREGEX > ... > #endif > > regards, > > John Maddock Sorry, but I haven't had a chance to answer. Ok it's works. But I need 'wide character support' much later. best regards, Rene Gutschmidt

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RE: [Boost-Users] Re: boost::noncopyable usage question
by Michael Davis 06 Jun '02

06 Jun '02

Thank you for the clarification. :) -----Original Message----- From: Darin Adler To: Boost-Users(a)yahoogroups.com Sent: 6/6/2002 12:57 AM Subject: Re: [Boost-Users] Re: boost::noncopyable usage question On Wednesday, June 5, 2002, at 03:14 PM, Michael Davis wrote: > According to the C++ Standard, 12.8/10, the assignment operator cannot > be > inherited because if it is not provided, the compiler will provide one > implicitly. Or at least, that is my understanding of it. > > Given this, how can boost::noncopyable work? The assignment operator provided by the compiler for the class derived from noncopyable has to copy the part of the object that's inherited from noncopyable. To do that, it has to use the assignment operator from the noncopyable class; but if it's inaccessible, like the private one in noncopyable, it has to report an error. This rule is mentioned in 12.8/14. -- Darin Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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