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asio - improving chat server example for my usage
by john grant 18 May '12

18 May '12

Hi,I could use some help to build on Asio's chat_server example so I can use it in my app. I want the server to have a main thread loop, like you would need if the server had a user interface or some other responsibility than just accepting client connections and echo-ing their input. I added a thread_group to call 'io_service::run' (to allow for asynchronous connections), letting the server have a main app loop for other responsibilities. I've learned enough about Asio by watching and reading Michael Caisse's excellent Asio presentation from BoostCon 2010 to feel somewhat comfortable using Asio and Threads together. I have a client app that connects well with the server app. ** I have a problem with my server app upon shutdown. The problem is that the thread_group I am using is stuck at the 'join_all' call (in the server app class's destructor). ** 1- I was worried that the threads were all dead, so I added a work object to my server app class, and now I delete it before I call 'join_all', but it still hangs here. 2- This might be way off, but I also wondered if I need to close all the sockets so that the thread group could join. I added 2 member functions to help me: void chat_server::close() { room_.close(); } void chat_room::close() { std::for_each( participants_.begin(), participants_.end(), boost::bind(&chat_room::leave, this, _1) ); } I call this in my server app class's destructor before calling thread_group::join_all, but this has a crash. The crash occurs right after chat_room::close() completes. I'm not confident in the way I used bind(...), but I was able to see the function execute, and then the crash occurs later. ** Do you know what I am doing wrong that causes the thread_group to hang? If I need to close the sockets, can you show me how to do that so I do not crash my app? ** For additional context, my server needs to send vehicle state to clients, among other messages. The server has a real time physics simulation. My client app will show a representation of the physics simulation. Many thanks for any help. I'm really enjoying Asio and other parts of Boost, but I still don't understand the framework completely. By the way, the IRC channel has been a big help already, but it seems everyone is busy in Aspen. :) John

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[filesystem] Memory leaks when building with MSVC 2010
by Christian Henning 18 May '12

18 May '12

Hi there, I'm stumbling over some memory leaks reported by MSVC when using boost::filesystem. Here is simple code sample that can reproduce the output below: #define _CRTDBG_MAP_ALLOC #include <stdlib.h> #include <crtdbg.h> #define BOOST_FILESYSTEM_VERSION 3 #include <boost/filesystem/convenience.hpp> namespace fs = boost::filesystem; int main(int argc, char* argv[]) { fs::path my_path( "C:\\bla.dat" ); _CrtDumpMemoryLeaks(); return 0; } -- Output: 'test.exe': Loaded 'C:\gil_contributions\solutions\vc10\test\x64\Debug\test.exe', Symbols loaded. 'test.exe': Loaded 'C:\Windows\System32\ntdll.dll', Cannot find or open the PDB file 'test.exe': Loaded 'C:\Windows\System32\kernel32.dll', Cannot find or open the PDB file 'test.exe': Loaded 'C:\Windows\System32\KernelBase.dll', Cannot find or open the PDB file 'test.exe': Loaded 'C:\Windows\System32\msvcr100d.dll', Symbols loaded. 'test.exe': Loaded 'C:\Windows\System32\msvcp100d.dll', Symbols loaded. Detected memory leaks! Dumping objects -> {268} normal block at 0x0000000000457450, 32 bytes long. Data: <C : \ b l a . d > 43 00 3A 00 5C 00 62 00 6C 00 61 00 2E 00 64 00 {145} normal block at 0x0000000000457F50, 24 bytes long. Data: < .? > A8 09 2E 3F 01 00 00 00 01 00 00 00 00 00 00 00 {143} normal block at 0x0000000000457E50, 16 bytes long. Data: <8 > 38 F9 16 00 00 00 00 00 00 00 00 00 00 00 00 00 {142} normal block at 0x0000000000457DD0, 16 bytes long. Data: <@ .? > 40 8B 2E 3F 01 00 00 00 00 00 00 00 00 00 00 00 {141} normal block at 0x0000000000457D50, 16 bytes long. Data: < .? > 10 8B 2E 3F 01 00 00 00 00 00 00 00 00 00 00 00 Object dump complete. The program '[1860] test.exe: Native' has exited with code 0 (0x0). Is this a known issue/nonissue? I have a test suite that uses boost::filesystem in numerous areas and the output is somewhat disturbing to me. Regards, Christian

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[msm] euml submachine with non-default constructor
by squiremyrkle＠fastmail.fm 17 May '12

17 May '12

Hello, having trouble getting this to work. Here’s a simplification of what I’m trying: //states and events defined elsewhere struct sub_fsm : public msm::front::state_machine_def<sub_fsm, state_base> { typedef entry_state_impl initial_state; BOOST_MSM_EUML_DECLARE_TRANSITION_TABLE(( entry_state + some_event() / action1 == next_state ), transition_table) sub_fsm() : pctx_(nullptr) {} sub_fsm(context *p) : pctx_(p) {} context *pctx_; }; typedef msm::back::state_machine<sub_fsm> sub_helper; struct sub_machine : public sub_helper, public msm::front::euml::euml_state<sub_helper> { sub_machine() {} sub_machine(context *p) : sub_helper(p) {} }; sub_machine const sub; struct outer_fsm : public msm::front::state_machine_def<outer_fsm, state_base> { typedef outer_entry_state_impl initial_state; BOOST_MSM_EUML_DECLARE_TRANSITION_TABLE(( outer_entry_state + another_event() / action2 == sub ), transition_table) outer_fsm() : pctx_(nullptr) {} outer_fsm(context *p) : pctx_(p) {} context *pctx_; }; typedef msm::back::state_machine<outer_fsm> outer_machine; int main() { context ctx; outer_machine fsm(msm::back::states_ << sub_machine(&ctx), &ctx); } This doesn’t compile under VC2010, it can’t deduce the template arguments for operator <<(). Am I on the right track here? Should the template parameter of euml_state<> really be sub_helper and not sub_machine (I got that chunk of code from here: http://svn.boost.org/svn/boost/trunk/libs/msm/doc/HTML/examples/CompositeTu… What am I doing wrong? Thanks for any help, Mark -- http://www.fastmail.fm - Choose from over 50 domains or use your own

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[bimap] How to erase a single association in a many-to-many bimap?
by Vicente J. Botet Escriba 17 May '12

17 May '12

Hi, I have a bimap typedef bimap< multiset_of< tagged< Person*, consultant> >, multiset_of< tagged< Company*, client> >, with_info< tagged< ConsultancyContract*, contract> > > Consultancy; initialized as follows Consultancy consultancy; Person John("John"), Jane("Jane"); Company Dell("Dell"), HP("HP"); ConsultancyContract JohnContractD(10,1); ConsultancyContract JaneContractD(20, 2); ConsultancyContract JaneContractH(30, 3); consultancy.insert(Consultancy::value_type(&Jane, &Dell, &JaneContractD)); consultancy.insert(Consultancy::value_type(&Jane, &HP, &JaneContractH)); and I want to remove only the specific association Jane<->Dell and so I'm using consultancy.erase(Consultancy::value_type(&Jane, &Dell)); but then the resulting consultancy bimap is empty, while I expect the association Jane<->HP to be there yet. If I add before erasing consultancy.insert(Consultancy::value_type(&John, &Dell, &JohnContractD)); and then consultancy.erase(Consultancy::value_type(&Jane, &Dell)); all the associations concerning Jane are removed. What I'm doing wrong? How to erase a single association? Best, Vicente

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[container] scoped_allocator_adaptor for c++03 error
by Szymon Gatner 17 May '12

17 May '12

Hi, are new scoped allocators suppose to be supported by c++03 compilers? Just including scoped_allocator.hpp in VC2008 SP1 causes lots of erros due to variadic templates usage. Regards, Szymon Gatner

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[boost] Boost.Locale on mobile
by Klaim - Joël Lamotte 17 May '12

17 May '12

Hi, are there limitations in boost.locale that would prevent it's use on mobile platforms? For example: iOS, Android, other mobile platforms that allow native applications Or put in another way: are there known system limitations on some target platforms that prevent the use of all features of Boost.Locale or even forbid it's use? My current understanding is that there is no restriction, but as I am not an expert in this matter I prefer to ask more experienced users. Joel Lamotte

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Status of boost.lockfree
by niXman 16 May '12

16 May '12

Hello! Last update on git[1] - 6 months ago. I do not understand whether boost.lockfree is still developing? After reading this topic[2], I still do not understand whether boost.lockfree be accepted into the boost, and when to expect this? Will boost.lockfree be accepted into boost-1.50? [1] http://tim.klingt.org/git?p=boost_lockfree.git; [2] http://lists.boost.org/Archives/boost/2012/03/191491.php -- Regards, niXman

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unique_future without rvalue references
by John M. Dlugosz 16 May '12

16 May '12

I'm using Clang on the Mac without the C++11 dialect enabled in this project. With BOOST_NO_RVALUE_REFERENCES defined, in Boost 1.49, how can I write a function returning an object of type unique_future<T> ? I tried changing std::move to boost::move which I expected to work. I tried fiddling with thread_move_t explicitly. I can't get anything to work. What's the magic formula?

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segmentation fault using boost asio in linux.
by mozdemir 16 May '12

16 May '12

Hi, I am using Boost Asio and hitting a segmentation fault crash in ubuntu. I don't have any issue when this is run in the windows. it runs and after half an hour, it hits this crash. Below is the code that starts from beginning to the place that the segmentation fault happened. The interesting part is that I use io_strand all over the code and I don't see any thread-safety issue. In the program I use 2 threads that run the worker io_servece.run(). I also put some printf in the HandleSend() just before the crash. i can see that itr pointer is not valid even though m_pending_sends has one element in the list that is supposed to be this itr pointer. What could be wrong here? Thanks a lot, mustafa 06:49.20 [dbg] void Connection::HandleSend() itr size: 2869978912 m_pending_sends.size(): 1 void Connection::Start() { m_stopped = false; m_start_time = boost::posix_time::second_clock::local_time(); boost::system::error_code ec; boost::asio::ip::tcp::resolver resolver( m_hive->GetService() ); boost::asio::ip::tcp::resolver::query query( m_host, boost::lexical_cast< std::string >( m_port ) ); boost::asio::ip::tcp::resolver::iterator endpointIterator = resolver.resolve( query ); Connect(endpointIterator); return; } void Connection::Connect(tcp::resolver::iterator endpoint_iter) { LDBG_ << "void Connection::Connect()-1 symbol: " << m_symbol; if (endpoint_iter != boost::asio::ip::tcp::resolver::iterator()) { boost::asio::ip::tcp::endpoint endpoint = *endpoint_iter; m_socket.async_connect( endpoint, m_io_strand.wrap( boost::bind( &Connection::HandleConnect, shared_from_this(), boost::asio::placeholders::error, endpoint_iter ) ) ); } else { Stop(); } return; } void Connection::HandleConnect( const boost::system::error_code & error, boost::asio::ip::tcp::resolver::iterator endpoint_iterator ) { LDBG_ << "void Connection::HandleConnect()-1 symbol: " << m_symbol << " error: " << error << " HasError " << HasError() << " m_hive->HasStopped() " << m_hive->HasStopped(); if ( error || HasError() || m_hive->HasStopped() ) { StartError( error ); } else { if ( m_socket.is_open() ) { OnConnect( m_path ); } else { Connect(++endpoint_iterator); } } return; } void MyConnection::OnConnect( const std::string & host, uint16_t port, const std::string & path ) { Recv(); Send(); } void Connection::Send() { if (m_stopped) return; std::string str = "GET " + m_path + " HTTP/1.0\r\n\r\n"; str += "Host: " + m_host + "\r\n"; str += "Accept: */*\r\n"; str += "Connection: keep-alive \r\n\r\n"; std::vector< uint8_t > request; std::copy( str.begin(), str.end(), std::back_inserter( request ) ); m_io_strand.post( boost::bind( &Connection::DispatchSend, shared_from_this(), request ) ); // start the heartbeat timer for the next send msg. StartTimerHeartbeat(); return; } void Connection::DispatchSend( std::vector< uint8_t > buffer ) { bool should_start_send = m_pending_sends.empty(); m_pending_sends.push_back( buffer ); if ( should_start_send ) { StartSend(); } return; } void Connection::HandleSend( const boost::system::error_code & error, std::list< std::vector< uint8_t > >::iterator itr ) { if ( error || HasError() || m_hive->HasStopped() ) { StartError( error ); } else { OnSend( *itr ); if ( !m_pending_sends.empty() ) { m_pending_sends.erase( itr ); <<<<<<<<====== Segmentation Fault happens here StartSend(); } } return; } void Connection::StartSend() { if ( !m_pending_sends.empty() ) { boost::asio::async_write( m_socket, boost::asio::buffer( m_pending_sends.front() ), m_io_strand.wrap( boost::bind( &Connection::HandleSend, shared_from_this(), boost::asio::placeholders::error, m_pending_sends.begin() ) ) ); } return; } -- View this message in context: http://boost.2283326.n4.nabble.com/segmentation-fault-using-boost-asio-in-l… Sent from the Boost - Users mailing list archive at Nabble.com.

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[boost] [decimal] Proposed portable implementation ofstd::decimal
by Josh Quigley 16 May '12

16 May '12

Hi all. A first draft of this library is available at https://sourceforge.net/projects/stddecimal/ Runs on MSVC10 and gcc 4.6.3. Wraps the Intel implementation only, Until we resolve the licencing issue, top-level README contains detailed instructions about where to get 3rd party code and what to do with it. I'm keen on feedback on a particular point (although all feedback is of course welcome!): The current project can parse and execute the test cases maintained by Mike Cowlishaw from http://speleotrove.com/decimal/ (referred to as the Test Cases). To be completely clear, I also have normal, interface testing test cases, I am *not* talking about those below. - Question: How useful do people feel the Test Cases to be? I originally expected 99% of these tests to pass, but it turns out that most of them require: - The operands to be parsed and stored at the precision they appear in the Test Case file - The operation to be performed at precision of the operands - The high precision result to be rounded to the precision required by the Test Cases. - The test inputs to be parsed with correct rounding in underflow situations (not required by IEEE afaik) The above requirements are based on my experience with the tests - it is possible I'm making a blunder somewhere. Since the Test Cases are really testing the 3rd party library, an argument could be made they are not essential, or even desirable. I'm inclined to think they would be very, very nice to have, as they would give users a lot of confidence - I suspect user uptake would be poor without this confidence. So... what do people think? Regards, Josh.

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