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[Signals] Observation about performance
by Keith MacDonald 16 May '05

16 May '05

I have an application that implements the Observer pattern, based on the GOF code and was interested in using Boost.Signals in a new application. Before committing myself, I decided to check the relative performance when signalling two observers. Both tests were performed on Windows XP, using MSVC 8 beta 2, with the /Ox optimisation. Here are the times for 6,000,000 signals, measured with the Win32 GetTickCount() API on a 3GHz P4 with 1GB RAM: GOF Observer: 109 Boost.Signals: 6203 Clearly, you have to trade convenience for performance with this library. - Keith MacDonald

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Declaring boost.serialization archivers as members
by Eyal Susser 16 May '05

16 May '05

Hi, After doing what I described in the subject, I found that when marshalling data between processes, the same data gets sent over and over again. It's as if the archiver has some internal copy of the stream, and keeps serializing that stream over and over. Anyone else have this problem, or is it some pitfall in my implementation? Thanks

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Compiler status table for Boost v1.32?
by Moore, J. David 16 May '05

16 May '05

Hello, I am interested in seeing the compiler status page for the 1.32 release of Boost. I was able to follow links on www.boost.org to see the compiler status for the head of the cvs repository: http://www.meta-comm.com/engineering/boost-regression/CVS-HEAD/developer /index.html, However, I could not find information for previous releases. Is this information archived anywhere? Thanks, Dave Moore IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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numeric conversion lib documentation
by Jeremy Siek 16 May '05

16 May '05

The docs for the converter class are missing descriptions of the two most important template parameters, T and S. http://www.boost.org/libs/numeric/conversion/doc/converter.html Cheers, Jeremy _______________________________________________ Jeremy Siek <jsiek(a)osl.iu.edu> http://www.osl.iu.edu/~jsiek Ph.D. Student, Indiana University Bloomington C++ Booster (http://www.boost.org) _______________________________________________

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Can boost::threads be started in detached state ?
by Shetty, Diwakar 16 May '05

16 May '05

Hi, I am using boost:thread. There does not seem to be any constructor which specifies whether the thread can be started in detached state. Will I have to use the native OS threading calls to do this? Thanks, Diwakar

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RE: [Boost-users] Re: Question
by Sliwa, Przemyslaw (London) 16 May '05

16 May '05

This returns in both cases the same value. Is there a way around this problem at all? Thanks Pshemek -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Eric Niebler Sent: 12 May 2005 18:13 To: boost-users(a)lists.boost.org Subject: [Boost-users] Re: Question Sliwa, Przemyslaw (London) wrote: > Thanks for help, > > I have an additional question. Does anyone know why the following > program gives different output on VC++ 6 and VC++ 2003 NET? It is pretty > strange, isn't it? > <snip> VC6 is pretty strange, I agree. In particular, it doesn't handle functions with non-type template parameters well. The following code should demonstrate the problem. (Hopefully I'm remembering the problem correctly -- I don't have VC6 installed on this machine.) template<int I> void foo() { std::cout << I << '\n'; } int main() { foo<1>(); foo<2>(); return 0; } If you must use VC6, avoid non-type template parameters for function templates. -- Eric Niebler Boost Consulting www.boost-consulting.com _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users -------------------------------------------------------- If you are not an intended recipient of this e-mail, please notify the sender, delete it and do not read, act upon, print, disclose, copy, retain or redistribute it. Click here for important additional terms relating to this e-mail. http://www.ml.com/email_terms/ --------------------------------------------------------

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shared_ptr, intrusive_ptr ...
by Jean-François Brouillet 15 May '05

15 May '05

I'm confused again :( I've read the note about shared_ptr & this in the documentation, but I'm still a bit lost as to how I'm supposed to overcome the problem. The code below would work fine if I were to remove all this smart pointer business and handle new & delete by hand. But because this kind of code is just so typical of the huge Java library I'm porting, there's not much choice but to get an as "surprise free" object model as possible. As far as I understand what is going on, the reason why the runtime is reporting a "double free" is because two independently constructed shared_ptrs' do not share the same reference count, which intrusive_ptr would allow me to do, except that intrusive_ptr doesn't vary "polymorphically" with its body as shared_ptr does. Obviously, I could "roll my own" solution by modifying shared_ptr to use a common reference count the way intrusive_ptr does, but I was wondering: is that my only course of action? Or has anyone found a workaround/clever use of the boost::xxx_ptr to overcome this situation? Many thanks -- JFB #include <iostream> #include <boost/shared_ptr.hpp> struct TaskDoneStruct { virtual void success() = 0 ; virtual void failure() = 0 ; } ; typedef boost::shared_ptr<TaskDoneStruct> TaskDone ; struct LongTaskStruct { TaskDone callback ; virtual void setCallback(const TaskDone& td) { this->callback = td ; } virtual void run() { start() ; complete() ; } virtual void start() = 0 ; virtual void complete() { if (callback) { callback->success() ; } } virtual ~LongTaskStruct() {} } ; struct MyTaskStruct : public LongTaskStruct, TaskDoneStruct { MyTaskStruct() { setCallback(TaskDone(this)) ; // this is the root of the // double free problem } virtual void start() { std::cout << "Starting lengthy process ..." << std::endl ; } virtual void success() { std::cout << "Done lengthy process ..." << std::endl ; } virtual void failure() { std::cout << "Aborted lengthy process ..." << std::endl ; } } ; typedef boost::shared_ptr<MyTaskStruct> MyTask ; void tastTest() { MyTask myTask(new MyTaskStruct) ; myTask->run() ; } int main( int argc , char * argv) { std::cout << "Tests starting ..." << std::endl ; tastTest() ; std::cout << "Tests done ..." << std::endl ; return 0 ; } /* BoostTests(1270) malloc: *** Deallocation of a pointer not malloced: 0x300180; This could be a double free(), or free() called with the middle of an allocated block; */

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Re: shared_ptr, intrusive_ptr ...
by Gottlob Frege 15 May '05

15 May '05

> Date: Sun, 15 May 2005 12:00:55 +0100 > From: Jean-Fran?ois Brouillet <verec(a)mac.com> > Subject: [Boost-users] Re: shared_ptr, intrusive_ptr ... > To: boost-users(a)lists.boost.org > Message-ID: <A42134A2-8F76-4A80-956A-D0070056100F(a)mac.com> > Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed > > On 2005-05-15 00:49:54 +0100, "Peter Dimov" <pdimov(a)mmltd.net> said: > > > Anyway, here's my revised snippet that satisfies all my criteria: > -- > JFB > > #include <iostream> > > #include <boost/intrusive_ptr.hpp> > > struct ObjectStruct { > int refCount ; > > ObjectStruct() : refCount(0) { > std::cout << std::hex << (int) this << " - I'm born" << > std::endl ; > } > > void refer() { ++refCount ; } > void unrefer() { if (--refCount == 0) delete this ; } > > virtual ~ObjectStruct() { > std::cout << std::hex << (int) this << " - I'm gone" << > std::endl ; > } > } ; > > void intrusive_ptr_add_ref(ObjectStruct * p) { p->refer() ; } > void intrusive_ptr_release(ObjectStruct * p) { p->unrefer() ; } > Are you going to make it thread-safe (or is that something you just left out of the example?)?

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[ANN][fsm][statechart] New interface available
by Andreas Huber 15 May '05

15 May '05

During the review it was decided to change the interface of the fsm submission as follows: - Library name and namespace are changed to statechart - Reactions are specified with a member typedef in the state type instead of a type that is passed as template argument A version with the above changes applied can be found in the sandbox under the statechart directories and here: http://boost-sandbox.sf.net/Statechart.zip The docs can also be browsed online: http://boost-sandbox.sf.net/libs/statechart I have not yet had the time to document the new reaction specification interface but it should be obvious how to use it from the examples and the tests. Feedback is highly welcome. Thanks & Regards, Andreas P.S. Future posts regarding this library will no longer carry the tag [fsm] but only [statechart] -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header.

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looped typedefs and/or class definitions
by martin f krafft 14 May '05

14 May '05

Some of my code includes the following (abbreviated): typedef Edge<Node0000Type, Node0000Type> Edge00000000Type; typedef Edge<Node0000Type, Node0001Type> Edge00000001Type; typedef Edge<Node0000Type, Node0010Type> Edge00000010Type; typedef Edge<Node0000Type, Node0011Type> Edge00000011Type; //... you can imagine where this is going. Instead of 32 typedefs, I was wondering if it weren't possible to use the compiler to achieve the above. Similarly, let's say I wanted to define a set of empty classes: class AB : public A, B {}; class AC : public A, C {}; class BC : public B, C {}; can I use the compiler to automate this? Thanks for any comments. -- martin; (greetings from the heart of the sun.) \____ echo mailto: !#^."<*>"|tr "<*> mailto:" net@madduck invalid/expired pgp subkeys? use subkeys.pgp.net as keyserver! spamtraps: madduck.bogus(a)madduck.net "arguments are extremely vulgar, for everyone in good society holds exactly the same opinion." -- oscar wilde

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