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boost::recursive_mutex for thread-safe logging crashing
by Ani Taggu 03 Sep '02

03 Sep '02

Hello: I have a simple class to do simple thread-safe logging using recursive_mutex as shown below. The problem is, once in a while, it causes any thread to die while it tries to log. I haven't been able to isolate why this happens. Is recursive_mutex being used correctly? The logging is done like so: extern FileLogger &TheLog() { static g_log("my.log"); return g_log; } TheLog() << "Hello World" << endl; I am using boost 1_28 with MSVC 6 SP5. ---------------------------------------------------------------------------- ------------------ #include <fstream> #include <string> #include "boost/thread/recursive_mutex.hpp" class FileLogger { public: // set second arg = false to do no logging. FileLogger(const std::string &logName, bool log=true) : log_(log) { if (log_) { strm_.open(logName.c_str(), std::ios::ate); } } // logging can be accessed from any thread. template <typename T> std::ostream & operator<< (T d) { if (log_) { boost::recursive_mutex::scoped_lock l(strmMutex_); strm_ << d; } return strm_; } ~FileLogger() { if (log_) { strm_.close(); } } private: std::ofstream strm_; boost::recursive_mutex strmMutex_; bool log_; };

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RE: [Boost-Users] tuple and enums
by Tom Matelich 03 Sep '02

03 Sep '02

Hello Jaakko, Thanks for replying. It works if the constructor is written cons() {} Is there any purpose to putting those default calls there? Tom > From: Jaakko Jarvi [mailto:jajarvi@cs.indiana.edu] > Sent: Thursday, August 29, 2002 8:16 AM > > Hi Tom, > > Your code compiles fine with gcc 3.x and icc 6 (linux), so it may just > be gcc 2.96 problem. > > Cheers, Jaakko > > On Wed, 28 Aug 2002, Tom Matelich wrote: > > > It appears that an enum cannot be default constructed in > the way that > > tuple > > does, > > cons() : head(), tail() {} > > > > Any idea on how to get around this (besides using an int in > the tuple)? > > > > Thanks, > > Tom > > > > > > <sample_code> > > > > #include <boost/tuple/tuple.hpp> > > #include <string> > > > > enum Foo { Willis, Arnold }; > > > > void test() > > { > > boost::tuple<Foo, std::string> a; > > } > > > > </sample_code> > > > > </error compiler="gcc version 2.96 20000731 (Mandrake Linux 8.2)"> > > > > > /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp: In > > method > > `boost::tuples::cons<HT, > > TT>::cons () [with HT = Foo, TT = boost::tuples::cons<string, > > boost::tuples::null_type>]': > > > /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp:454: > > instantiated from `boost::tuples::tuple<T0, T1, T2, T3, T4, > T5, T6, T7, > > T8, > > T9>::tuple () [with T0 = Foo, T1 = string, T2 = > > boost::tuples::null_type, T3 > > = boost::tuples::null_type, T4 = boost::tuples::null_type, T5 = > > boost::tuples::null_type, T6 = boost::tuples::null_type, T7 = > > boost::tuples::null_type, T8 = boost::tuples::null_type, T9 = > > boost::tuples::null_type]' > > tuple_enum_test.cpp:8: instantiated from here > > > /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp:263: > > cannot convert `int' to `Foo' in > > assignment > > > > </error> > > > > > > > -------------------------------------------------------------- > --------- > > DISCLAIMER: Information contained in this message and/or > > attachment(s) may contain confidential information of Zetec, Inc. > > If you have received this transmission in error, please notify > > the sender by return email. > > > -------------------------------------------------------------- > --------- > > > > Yahoo! Groups Sponsor > > ADVERTISEMENT > > > > 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 the Yahoo! Terms of Service. > -- -- -- Jaakko Järvi email: jajarvi(a)cs.indiana.edu -- Post Doctoral Fellow phone: +1 (812) 855-3608 -- Pervasive Technology Labs fax: +1 (812) 855-4829 -- Indiana University, Bloomington 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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RE: [Boost-Users] tokenizer
by Jim.Hyslop 03 Sep '02

03 Sep '02

Vijay (macrodisk(a)yahoo.com) wrote: > Is there anyway I can combine two tokens and check it as single one? > > I want to divide my string when both "-" and ">" occur together: > > Cell 12-1 -> xyz... > > I want to get the first token as Cell 12-1, how can I achive this via > tokenizer? I haven't used the tokenizer, but it seems to me that your TokenizerFunction can peek at the character after the '-' to see if it is a '>', to determine whether it should treat the '-' as a regular character or part of a separator. -- Jim

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Problems with MSVC-STLPORT toolset
by davlet_panech 03 Sep '02

03 Sep '02

Hello, I'm having problems building release 1.28 with MSVC 6/STLPort 4.5.3/bjam on Windows NT 4. It seems that bjam tries to make a very VERY deep directory tree which at some point becomes too large due to path name limitations. By looking at the trace messages it seems something is very wrong there :) -- the directory tree is modelled after the command line options with some of the options repeated with different values at different levels in the tree. For example the following target fails (and there a few cases similar to this one; so that nothing gets compiled): mkdir libs\regex\build\bin\libboost_regex.lib\msvc- stlport\stlport-iostream-on\debug-symbols-on\exception-handling- on\inlining-off\optimization-off\rtti-on\runtime-build-debug\runtime- link-dynamic\stlport-cstd-namespace-std\stlport-iostream-off ...failed MkDir1 libs\regex\build\bin\libboost_regex.lib\msvc- stlport\stlport-iostream-on\debug-symbols-on\exception-handling- on\inlining-off\optimization-off\rtti-on\runtime-build-debug\runtime- link-dynamic\stlport-cstd-namespace-std\stlport-iostream-off... Notice how the path includes both stlport-iostream-off and stlport- iostream-on components. The command line I was using: bjam \ -sTOOLS=msvc-stlport \ -sBUILD=stlport-iostream-on -sSTLPORT_4.5.3_PATH="h:\PROGRA~1\MICROS~1\VC98\INCLUDE\stlport" The MSVC-specific environment was set up correctly (MSVCDir, INCLUDE, LIB). The STLPORT_4.5.3_PATH points to the directory containing the STLPort headers. What am I doing whrong? Thanks, D.P.

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[bind] does bind do overload resolution?
by Alex Henderson 02 Sep '02

02 Sep '02

Hi, I'd like boost::bind to use overloaded member functions, but get an internal compiler error. Does bind support overload resolution, or is my compiler at fault? (...or more likely the code!) system = C++Builder 5 (patched), Win2k, boost_1_28_0 example (simplified) code below Thanks, Alex //-------------------------------------------------------------------- ------- #include <string> #include <vector> #include <iostream> #include <boost/bind.hpp> //-------------------------------------------------------------------- ------- struct part { std::string name; int id; part(std::string name, int id) : name(name), id(id) {} bool is(int test) { return id == test; } // bool is(std::string test) { return name == test; } // uncomment for error }; //-------------------------------------------------------------------- ------- int main() { int x = 6; // swap comments here for error // std::string x("handle"); // swap comments here for error std::vector<part> parts; part a("top", 3); parts.push_back(a); part b("spout", 6); parts.push_back(b); part c("handle", 9); parts.push_back(c); std::vector<part>::iterator it = std::find_if(parts.begin(), parts.end(), boost::bind(&part::is, _1, x)); std::cout << it->name << std::endl; return 0; } //-------------------------------------------------------------------- -------

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Question about scoped_ptr.hpp and config.hpp
by eldritchshadows 31 Aug '02

31 Aug '02

Is there a reason that scoped_ptr.hpp doesn't have config.hpp up at the top like shared_ptr.hpp? When I included it, it got rid of a lot of MSVC++ warnings. Nathan

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shared_ptr and make_indirect_iterator
by Richard Wolf 31 Aug '02

31 Aug '02

Hi I'm trying to use make_indirect_iterator on a container of shared_ptrs as follows: #include <boost/iterator_adaptors.hpp> #include <boost/shared_ptr.hpp> #include <list> #include <algorithm> #include <functional> using std::mem_fun_ref; using std::mem_fun; using std::list; using boost::shared_ptr; using std::for_each; using boost::make_indirect_iterator; class A { public: void f(){} }; int main() { list<A *> List1; list<shared_ptr<A> > List2; // This works for_each(make_indirect_iterator(List1.begin()), make_indirect_iterator(List1.end()), mem_fun_ref(&A::f)); // This doesn't work for_each(make_indirect_iterator(List2.begin()), make_indirect_iterator(List2.end()), mem_fun_ref(&A::f)); } The second use of for each fails to compile (error messages at the end of the message). Is it possible to do this? Am I doing something wrong? I'm using gcc v 2.95.2. and the QNX OS. Thanks Richard QCC -I/home/rwolf/boat/src/includes -I/home/rwolf/boat/src/boost_1_27_0 -Wal l -L/home/rwolf/boat/src/lib -L. -O -g -I/home/rwolf/boat/src/includes -I/h ome/rwolf/boat/src/boost_1_27_0 -Wall test.cpp -o test /usr/include/xutility: In instantiation of `std::iterator_traits<boost::shared_ptr<A> >': /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1104: instantiated from `boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::all ocator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: instantiated from here /usr/include/xutility:81: no type named `iterator_category' in `class boost::shared_ptr<A>' /usr/include/xutility:82: no type named `value_type' in `class boost::shared_ptr<A>' /usr/include/xutility:83: no type named `difference_type' in `class boost::shared_ptr<A>' /usr/include/xutility:84: no type named `difference_type' in `class boost::shared_ptr<A>' /usr/include/xutility:85: no type named `pointer' in `class boost::shared_ptr<A>' /usr/include/xutility:86: no type named `reference' in `class boost::shared_ptr<A>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp: In instantiation of `boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::all ocator<boost::shared_ptr<A> > >::iterator>': /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: instantiated from here /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1104: no type named `value_type' in `struct std::iterator_traits<boost::shared_ptr<A> >' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1105: no type named `reference' in `struct std::iterator_traits<boost::shared_ptr<A> >' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1106: no type named `pointer' in `struct std::iterator_traits<boost::shared_ptr<A> >' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp: In function `int main()': /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `value_type' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `reference' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `pointer' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 2 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 3 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 5 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp: At top level: /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp: In instantiation of `boost::make_indirect_iterator<std::list<boost::shared_ptr<A>,std::allocator <boost::shared_ptr<A> > >::iterator>(...)': test.cpp:26: instantiated from here /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `value_type' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `reference' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: no type named `pointer' in `struct boost::detail::traits_of_value_type<std::list<boost::shared_ptr<A>,std::allo cator<boost::shared_ptr<A> > >::iterator>' /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 2 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 3 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: template argument 5 is invalid /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp: In function `{error} boost::make_indirect_iterator<std::list<boost::shared_ptr<A>,std::allocator< boost::shared_ptr<A> > >::iterator>(...)': /home/rwolf/boat/src/boost_1_27_0/boost/iterator_adaptors.hpp:1177: confused by earlier errors, bailing out cc: /usr/lib/gcc-lib/ntox86/2.95.2/cc1plus error 34 make: *** [test] Error 1

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tokenizer
by Vijay 30 Aug '02

30 Aug '02

Hello, Is there anyway I can combine two tokens and check it as single one? I want to divide my string when both "-" and ">" occur together: Cell 12-1 -> xyz... I want to get the first token as Cell 12-1, how can I achive this via tokenizer? Thank you, Vijay

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msvc-stlport build problems
by David Resnick 30 Aug '02

30 Aug '02

Hi, I'm trying to build boost version 1.28.0, msvc-stlport build, using the following line: bjam -sTOOLS=msvc-stlport -sstlport-iostream=on -sSTLPORT_PATH=c:\etc I have no problems building the msvc build. It seems to me that the problem has to do with the MS Platform SDK that I have installed. When compiling STLPort (version 4.5.3) I had similar warnings. 2 work arounds that I found there were either to remove the platform SDK from the include enviroment variable, or (when I found it) to define _STLP_NEW_PLATFORM_SDK in stl_user_config.h. I've tried variations of that with compiling Boost, but nothing makes a difference. I've included the error messages that I get for most files. ---------------------------- CUT HERE ---------------------------- vc-C++ libs\regex\build\bin\libboost_regex.lib\msvc-stlport\debug\runtime-link- dynamic\stlport-cstd-namespace-std\stlport-ios tream-off\stlport-version-4.5.3\c_regex_traits.obj c_regex_traits.cpp C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1011) : error C2733: second C linkage of overloaded function 'InterlockedIncremen t' not allowed C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1009) : see declaration of 'InterlockedIncrement' C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1018) : error C2733: second C linkage of overloaded function 'InterlockedDecremen t' not allowed C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1016) : see declaration of 'InterlockedDecrement' C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1026) : error C2733: second C linkage of overloaded function 'InterlockedExchange ' not allowed C:\PROGRA~1\MICROS~3\VC98\include\winbase.h(1023) : see declaration of 'InterlockedExchange' "cl" /Zm400 -nologo -GX -c -DBOOST_REGEX_NO_LIB=1 -DBOOST_REGEX_STATIC_LINK=1 -D_STLP_NO_SGI_IOSTREAMS=1 -D_STLP_DO_IMP ORT_CSTD_FUNCTIONS=1 -D_STLP_DEBUG=1 -D_STLP_DEBUG_UNINITIALIZED=1 -D_STLP_NEW_PLATFORM_SDK=1 /Z7 /Od /Ob0 /GX /GR /MDd -I "libs\regex\build" -I"C:\etc\boost_1_28_0" -I"c:\etc\STLport-4.5.3\stlport" -I"C:\PROGRA~1\MICROS~3\VC98\include" -Fo"libs \regex\build\bin\libboost_regex.lib\msvc-stlport\debug\runtime-link-dyna mic\stlport-cstd-namespace-std\stlport-iostream-off\s tlport-version-4.5.3\c_regex_traits.obj" -Tp"libs\regex\build\../src\c_regex_traits.cpp" ...failed vc-C++ libs\regex\build\bin\libboost_regex.lib\msvc-stlport\debug\runtime-link- dynamic\stlport-cstd-namespace-std\s tlport-iostream-off\stlport-version-4.5.3\c_regex_traits.obj... ---------------------------- CUT HERE ---------------------------- Thanks in advance, David Resnick MobileSpear Inc.

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BJam and XEmacs on WinXP
by Dan Muller 30 Aug '02

30 Aug '02

This may be a tad off-topic, but I couldn't find any reference to this relative to XEmacs, and the problem seems to be peculiar to bjam. If I try to run bjam under XEmacs, e.g. via M-x compile, M-x shell-command, or even from inside an XEmacs shell buffer (running CMD), I get the error "spawn: Invalid argument". More specifically, if I run it via shell-command, I get this: ===================== ...found 331 targets... ...updating 1 target... gcc-Archive-action ..\phys_sim\bin\libphys_sim.lib\gcc-nocygwin\debug\architecture-native\debug-symbols-on\inlining-off\optimization-off\profiling-off\rtti-on\runtime-build-debug\runtime-link-dynamic\threading-single\vtable-thunks-default\libphys_sim.lib spawn: Invalid argument ====================== ... which indicates that bjam is in fact starting, but has some problem. Or maybe the tools do. If I run it in the same directory from a regular command window, it works fine. I'm running XEmacs 21.4, with recently updated packages. The bjam executable was downloaded yesterday. (I'm trying to use it for something other than Boost, BTW.) The toolset I'm using is MinGW, the latest stable full-package release, with no package updates. Anyone have an idea what might be wrong? I'm getting tired of looking at my build output in a command window and then hunting for line numbers in my source code. :-)

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problem with preprocessing library
by Ellis Cohen 30 Aug '02

30 Aug '02

Using the Boost preprocessor library, I'm getting an unexpected diagnostic from the HP-UX C++ compiler (aCC, version "HP ANSI C++ B3910B A.03.34"). The generated output -- see the last line of "Compiler output", below -- *is* correct. I'm using Boost_1_28_0. Is my use of the preprocessor library incorrect? Ellis Cohen ======================================================================== Code fragment triggering the diagnostic: #include <boost/preprocessor/cat.hpp> #include <boost/preprocessor/comma_if.hpp> #include <boost/preprocessor/repeat.hpp> #include <boost/preprocessor/tuple/elem.hpp> #define FOO0 (0, double, some_value) #define FOO1 (0, double, some_other_value) #define FOO2 (0, double, some_other_other_value) #define FOO_CNT 3 #define PPV(I) FOO##I #define PPV_FLAG(I) BOOST_PP_TUPLE_ELEM(3,0,PPV(I)) #define PPV_TYPE(I) BOOST_PP_TUPLE_ELEM(3,1,PPV(I)) #define PPV_NAME(I) BOOST_PP_TUPLE_ELEM(3,2,PPV(I)) #define BOOST_PP_DEF(I,_) BOOST_PP_COMMA_IF(I) BOOST_PP_CAT(d_,PPV_NAME(I))(BOOST_PP_CAT(other.d_,PPV_NAME(I))) BOOST_PP_REPEAT(FOO_CNT, BOOST_PP_DEF, _) #undef BOOST_PP_DEF ======================================================================== Compiler command: /opt/aCC/bin/aCC \ -Iboost_includes \ -Wc,-ansi_for_scope,on \ -Aa \ +inst_compiletime +inst_v \ -E -c Isrc/boost_bug.C -o boost_bug.o ======================================================================== Compiler output: Warning (anachronism) 823: "Isrc/boost_bug.C", line 18 # Redundant preprocessing concatenation operation results in two valid preprocessing tokens. Depending on this implementation defined behavior will result in non-portable code. BOOST_PP_REPEAT(FOO_CNT, BOOST_PP_DEF, _) ^^^^^^^^^^^^^^^ Warning (anachronism) 823: "Isrc/boost_bug.C", line 18 # Redundant preprocessing concatenation operation results in two valid preprocessing tokens. Depending on this implementation defined behavior will result in non-portable code. BOOST_PP_REPEAT(FOO_CNT, BOOST_PP_DEF, _) ^^^^^^^^^^^^^^^ Warning (anachronism) 823: "Isrc/boost_bug.C", line 18 # Redundant preprocessing concatenation operation results in two valid preprocessing tokens. Depending on this implementation defined behavior will result in non-portable code. BOOST_PP_REPEAT(FOO_CNT, BOOST_PP_DEF, _) ^^^^^^^^^^^^^^^ #line 1 "Isrc/boost_bug.C" #line 1 "boost_includes/boost/preprocessor/cat.hpp" #line 2 "Isrc/boost_bug.C" #line 1 "boost_includes/boost/preprocessor/comma_if.hpp" #line 1 "boost_includes/boost/preprocessor/comma.hpp" #line 17 "boost_includes/boost/preprocessor/comma_if.hpp" #line 1 "boost_includes/boost/preprocessor/empty.hpp" #line 18 "boost_includes/boost/preprocessor/comma_if.hpp" #line 1 "boost_includes/boost/preprocessor/if.hpp" #line 1 "boost_includes/boost/preprocessor/logical/bool.hpp" #line 17 "boost_includes/boost/preprocessor/if.hpp" #line 1 "boost_includes/boost/preprocessor/tuple/elem.hpp" #line 18 "boost_includes/boost/preprocessor/if.hpp" #line 19 "boost_includes/boost/preprocessor/comma_if.hpp" #line 3 "Isrc/boost_bug.C" #line 1 "boost_includes/boost/preprocessor/repeat.hpp" #line 4 "Isrc/boost_bug.C" #line 18 d_some_value( other.d_some_value) , d_some_other_value( other.d_some_other_value) , d_some_other_other_value( other.d_some_other_other_value)

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RE: [Boost-Users] boost::any and operator ==
by Jim.Hyslop 29 Aug '02

29 Aug '02

> How do I compare two boost::any values for equality? How to I compare > two containers of boost::any's for equality? > > Why doesn't boost::any define this operator? There has to be > a reason. There is. boost::any can, quite literally, hold *anything*. In order to compare the objects being held, you must first know if they _can_ be compared. Consider: const char * initialMessage = "Snowflakes keep falling on my head"; void f() { boost::any multiA(42L); boost::any multiB(initialMessage); //... It doesn't make sense to compare the two 'any' objects. I suppose boost::any could coerce the pointer into a long, and then apply a comparison operator, but the results of that comparison would be meaningless. In order to compare the objects, you'll have to extract them from the any container using an any_cast. Which, of course, means you'll have to know the exact type of the object being held (or which type of a known set of types). -- Jim

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Sorting a container of shared_ptr<T>
by alejandro_escalante_medina 29 Aug '02

29 Aug '02

Hello to everyone. I'm starting to take a look on Boost and was happy to find things like better smart pointers. Though, in my tests, I haven't been able to sort, say, a vector of shared_ptr without defining special comparators. I thought that the overload for the < operator would help me for that, but that operator compares pointers, not objects, so it doesn't do the work that I expected. I guess I'm not understanding this well. Could someone explain this to me? Saludos, Alex

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threads and signals question
by lparrab 29 Aug '02

29 Aug '02

Hi all, I guess my question is not specific to Boost.Thread, but to threading in general (I'm new at it)... still hope you can help me out, either directly or by redirecting me to the right place (links are very much appreciated) I'm starting a multi-threaded program using Boost.Thread library: it is a "server", in which a thread loops around a "select" to accept new connections and see when a socket has data to be read, in which case puts the fds in queue from which other threads are taking them out to read the data. The problem I have, is that when a "ReceiverThread" finishes reading the data from the socket, it puts the fd back in the "all connections list", but by this time the other ("main")thread already copied the fds from the list and got into the next "select" loop, which means the socket from which the "receiver" just finished reading, will not be "selected" (monitored) untill the next select loop, which will not be untill a) a new connection comes or b)one of the other connected sockets gets some data that takes makes the main thread return from select. reading the select man, I thought I could just use a signal to force select to return when the "receiver" has put the fd back in the "all connection list": the threads are now executing something like: main_thread { *put all fds from "all sockets" list into a fdset *make a select on the fdset (block till something interesting happens) *take the fds with data out of "all sockets" and put them into "sockets with data" *loop } receiver{ *get a fd from "sockets with data" (if nothing there blocks till the main_thread sends us a fd through the queue) *read from fd *put fd back into "all sockets" (problem: main_thread may be (is!) already into the select) *raise(SIGUSR1) (to force select to return and enter the loop again, but this time with our fd) } the signal handler for SIGUSR1 does nothing, it just serves to force select to return, but the code is not really working as I expected, and I realized that the problem is that each thread has its own pid, so it seems raise is actually sending a signal to the wrong thread.... as I said, I am new to mulithreading, but I thought all threads run in a process, which means, they all have the same pid. ->if I first find out the "pid" of the main_thread and change raise(SIGUSR1) to kill(pid,SIGUSR1) it works ok. so my question: why does each thread have a own pid?? how can then I send signals from one thread to another?? I discovered there is a "pthread_kill" function to send signals to specific threads, the problem is I only have boost::thread objects, no pthread_t structures. or am I talking nonsense and shouldnt be using signals with Boost.Thread? if so, how do I solve the select problem?? thanx! luis

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BGL: adjacency_list: remove_edge problems
by Matthias Kronenberger 29 Aug '02

29 Aug '02

I'm using a undirected grap with hash_setS as the Edge List container and vecS as the Vertex List Container I'm using MSVC60 with SP5 as soon as i'm trying to use remove_edge(vertex1,vertex2,graph) i get the following error message. I dont understand the error message. It means, that my edgelist is a std::vector allthough i compile with boost::hash_setS. Could it be, that some BGL config file detects MSVC and concludes, that hash sets are not available in the MSVC stl?? d:\matthias\programmieren\boost\boost\graph\detail\adjacency_list.hpp(665): error C2039: 'find': Ist kein Element von 'vector<boost::detail::sei_<unsigned int,list<boost::list_edge<unsigned int,boost::property<enum boost::edge_weight_t,float,boost:: no_property>>>::iter,boost::property<enum boost::edge_weight_t,float,boost::no_property>>,allocator<boost::detail::sei _<unsigned int,list<boost::list_edge<unsigned int,boost::property<enum boost::edge_weight_t,float,boost::no_property>>>::iter,boost ::property<enum boost::edge_weight_t,float,boost::no_property>>>>' find is not an element of vector the corresponding code fragment is. template <class Graph, class EdgeList, class Vertex> inline void remove_edge_and_property(Graph& g, EdgeList& el, Vertex v, boost::disallow_parallel_edge_tag) { typedef typename EdgeList::value_type StoredEdge; typename EdgeList::iterator i = el.find(StoredEdge(v)), end = el.end(); if (i != end) { g.m_edges.erase((*i).get_iter()); el.erase(i); } }

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Re: [Boost-Users] threads and signals question
by dick.bridges＠tais.com 29 Aug '02

29 Aug '02

My $.02. Check out the description of the Leader-Follower thread pattern described in Schmidt, et al, Pattern-Oriented Software Architecture, Volume 2, Patterns for Concurrent and Networked Objects. Sure is easy to implement with Boost libraries. Thank you everyone! Luis De la Parra <lparrab(a)gmx.net To: tomhoward(a)users.sourceforge.net, Boost-Users(a)yahoogroups.com > cc: Subject: Re: [Boost-Users] threads and signals question 08/29/2002 09:37 AM Please respond to Boost-Users > IMHO I wouldn't use select. Each time a new connections is initiated, you > can simply start a new thread to receive data from that socket. I don't > know what performance impact this would have, but the code will certainly > be simpler and easier to maintain. as I said, I'm new to threads.. and I know they are much more "leightweighted" than a normal process, but imagine a server, like an application server, which can have *a lot* of clients connected at the same time, but in which the clients are not really all requesting thigs all the time, they are "just connected" I think having a thread waiting on each open connection is not the right approach here, so I thought of going a kind of "production line" approach in which a few threads (5-10) are reading the data from a bunch of open connections (50-100), the only thing they do is read the data, parse it and form a "Request" which they put in a queue for further processing and then go on to service the other connections. Then another group of threads is taking this requests and doing something, and putting Response objects in yet another queue, which another group of threads "Sender" is taking and sending thorugh the socket. I think you get the idea: a frew threads just doing one thing and then passing the processing to another gorup of threads. I know having a thread dedicated to each connection would be much easier, but since this project is mostly for fun (and to learn!) I'd like to take a "better" approach (note that I am not saying the approach I just described is the best one, but right now it sounds more efficient and scalable to me than the one-trhead-per-connection approach) regards, luis.l 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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tuple and enums
by Tom Matelich 29 Aug '02

29 Aug '02

It appears that an enum cannot be default constructed in the way that tuple does, cons() : head(), tail() {} Any idea on how to get around this (besides using an int in the tuple)? Thanks, Tom <sample_code> #include <boost/tuple/tuple.hpp> #include <string> enum Foo { Willis, Arnold }; void test() { boost::tuple<Foo, std::string> a; } </sample_code> </error compiler="gcc version 2.96 20000731 (Mandrake Linux 8.2)"> /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp: In method `boost::tuples::cons<HT, TT>::cons () [with HT = Foo, TT = boost::tuples::cons<string, boost::tuples::null_type>]': /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp:454: instantiated from `boost::tuples::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::tuple () [with T0 = Foo, T1 = string, T2 = boost::tuples::null_type, T3 = boost::tuples::null_type, T4 = boost::tuples::null_type, T5 = boost::tuples::null_type, T6 = boost::tuples::null_type, T7 = boost::tuples::null_type, T8 = boost::tuples::null_type, T9 = boost::tuples::null_type]' tuple_enum_test.cpp:8: instantiated from here /usr/local/eddynet/opt/include/boost/tuple/detail/tuple_basic.hpp:263: cannot convert `int' to `Foo' in assignment </error> ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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shared_ptr const problem
by Olaf Petzold 28 Aug '02

28 Aug '02

Hi, now I have a new problem - const correctness. ---8<--- #include <iostream> #include <algorithm> #include <iterator> #include <vector> #include <boost/shared_ptr.hpp> class Doc { public: virtual ~Doc() { } public: const std::vector<double>& foo() const { return m_foo; } protected: std::vector<double>& foo() { return m_foo; } private: std::vector<double> m_foo; }; using namespace std; int main() { boost::shared_ptr<Doc> lp_doc( new Doc ); std::copy(lp_doc->foo().begin(), lp_doc->foo().end(), std::ostream_iterator<double>(cout, " ") ); cout << endl; } --->8--- `std::vector<double, std::allocator<double> >& Doc::foo()' is protected I hoped std::copy takes the const foo() member function. Thanks olaf

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iterator_adaptors on mipspro 7.3.1.3m
by marcinzalewski 28 Aug '02

28 Aug '02

Hi, I am trying to use iterator adaptors on mipspro and am unsuccessfull as for now. I was wandering if any of you has experience with boost and mipspro. Here are some examples of errors I am getting: ----------- cc-1132 CC: ERROR File = ../../boost_1_28_0/boost/iterator.hpp, Line = 54 The namespace "std" has no member "ptrdiff_t". template <class Category, class T, class Distance = std::ptrdiff_t, ^ or cc-3307 CC: ERROR File = ../../boost_1_28_0/boost/type_traits/array_traits.hpp, Line = 24 Invalid partial specialization--class "boost::is_array<<error-type>>" is already fully specialized. template <typename T, std::size_t N> struct is_array<T[N]> ----------- Please, let me know if you did this before. :) -m ^

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[BGL] undirectedS self-loop add_edge assertion
by Chris Russell 27 Aug '02

27 Aug '02

Just a quick mention: A call to add_edge with u == v causes an assertion if Directed == undirectedS. adjacency_list.hpp line 843: assert( u != v ); // don't allow self-loops ^- boost_1_28_0 Avoiding the assertion is easy enough but this is inconsistent w/section 14.1.1 p.220 of the BGL book: "... Also if u and v are descriptors for the same vertex (creating self loop) and the graph is undirected, then the edge will not be created and the flag will be false." Am having tons of fun - the BGL and the book are super. Thanks! - Chris

2 1

lambda library usage
by khuroth 27 Aug '02

27 Aug '02

I have a View class that has some widgets, and a Controller class that controls the view, so the View class has a GetController() member function that returns a reference to its controller. When the View's constructor is called, GetController() would return a bad ref, but it would return a valid reference by the time a button is clicked... so what I'm trying to do is, inside the View constructor: my_button.on_click = bind( (_1 ->* &A::GetController).DoSomething(), this ); but that obviously doesn't work... I'm even having trouble just saving the first part: my_button.on_click = bind<Controller&>(_1 ->* &A::GetController, this); also doesn't work... I tried defining the on_click member of the button as a boost::function<void> or a boost::function0<void> in the first example, and a boost::function<Controller&> or boost::function0<Controller&> in the second snip... I get immense compiler errors, so I'm not sure where I messed up. What am I doing wrong?

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shared_ptr swap problems
by Olaf Petzold 27 Aug '02

27 Aug '02

Hello, I've trouble with the follwong snippet: #include <iostream> #include <boost/shared_ptr.hpp> struct A { A(const char* n) : name(n) { } const char* name; }; struct B : public A { B(const char* n) : A(n) { std::cout << "construct " << name << std::endl; } ~B() { std::cout << "destruct " << name << std::endl; } }; struct BaseC { virtual void set(const boost::shared_ptr<A>& ptr) = 0; }; struct C : public BaseC { C() : b( new B("C::b") ) { } void set(const boost::shared_ptr<A>& ptr) { b.swap( boost::shared_static_cast<B>( ptr ) ); // L21 } void print() { std::cout << b->name << std::endl; } boost::shared_ptr<B> b; }; using namespace std; int main() { boost::shared_ptr<A> b( new B("b") ); C c; c.print(); c.set( b ); c.print(); } t.cc: In member function `virtual void C::set(const boost::shared_ptr<A>&)': t.cc:21: no matching function for call to `boost::shared_ptr<B>::swap(boost::shared_ptr<B>)' /usr/include/boost/shared_ptr.hpp:234: candidates are: void boost::shared_ptr<T>::swap(boost::shared_ptr<T>&) [with T = B] I did try boost::shared_polymorphic_cast to get a std::bad_cast exception - but it doesn't compile too. How can get it working? Thanks Olaf

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RE: [Boost-Users] How can checkout the files in Attic (hidden) fr om the cvs server?
by Jim.Hyslop 27 Aug '02

27 Aug '02

> I'm using WinCvs to checkout the current version of boost from the > cvs server. However, I found that I can not checkout some of the > libs which are put in the Attic, though I can browse them through my > internet browser. Anyone knows how to check these files out? (for > example, the mpl lib) Any files in the Attic are either obsolete, or have been added only on a branch and have not been merged to the trunk yet. Unless you are having a specific problem that requires a file from the Attic, then don't worry about what's up there (I suspect that's probably why it's called the "Attic" - out of sight, out of mind ;-) -- Jim

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How can checkout the files in Attic (hidden) from the cvs server?
by li_lirong 27 Aug '02

27 Aug '02

I'm using WinCvs to checkout the current version of boost from the cvs server. However, I found that I can not checkout some of the libs which are put in the Attic, though I can browse them through my internet browser. Anyone knows how to check these files out? (for example, the mpl lib) Thanks in advance, Lirong

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boost::any and operator ==
by billrobertson42 27 Aug '02

27 Aug '02

How do I compare two boost::any values for equality? How to I compare two containers of boost::any's for equality? Why doesn't boost::any define this operator? There has to be a reason. Thanks!

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