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dev_poll_reactor vs. strand and async_write
by Chris Hite 04 Jun '09

04 Jun '09

In a project using asio I noticed performance issues on Sun vs. Linux. It turned out that dev_poll_reactor is doing tones of system calls always pairs of write() and ioctl(). Stranger still is that the calls to write() are for 0 bytes. I was able to avoid the issue by switching from strand to mutex. I think there is some bug or logic error in dev_poll_reactor so I wrote a test program to narrow down when it happens: // Christopher Hite RTS Realtime Systems Software GmbH, Rembrandtstrasse 13, D-60596 Frankfurt am Main T: +49.69.61009.0 / F: +49.69.61009.181 Sitz: Frankfurt am Main - HRB 84467 Amtsgericht Frankfurt am Main Geschäftsführer: Steffen Gemuenden, Igor Sluga www.rtsgroup.net This email and any attachments are for the exclusive and confidential use of the intended recipient. If you are not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, please do not read, distribute or take action in reliance upon this message. If you have received this in error, please notify me immediately by return email and promptly delete this message and its attachments from your computer system. ------------------------------------------------------------------------------- #include <boost/asio.hpp> #include <iostream> using namespace boost::asio; io_service service; io_service::strand strand_(service); local::stream_protocol::socket s0(service); local::stream_protocol::socket s1(service); void wh(const boost::system::error_code& ec,const std::size_t){ if(ec) std::cout<<ec; //never happens } void sendAByte(){ static char sendBuf[256]; async_write(s0,buffer(sendBuf,1),wh); } int main(){ local::connect_pair(s0,s1); std::cout<<"dispatching\n"; for(int i=0;i<100000;i++) #if 1 strand_.dispatch(sendAByte); #else sendAByte(); //doesn't cause the sys calls #endif std::cout<<"waiting on run to finish\n"; service.run(); return 0; } //------------------------------------------------------------------------------- Here are some dtraces to help analyze what's going on $XX is the executable. This one shows all the calls to write() with size=0. async_write uses sendmsg() so all these are attributable to dev_poll_reactor. dtrace -n 'syscall::write:entry/pid==$target&&arg2==0/{ ustack(); }' -c $XX 0 5467 write:entry libc.so.1`_write+0x8 strandtest`__1cFboostEasioGdetailQdev_poll_reactor4b_Drun6Mb_v_+0x1b4 strandtest`__1cFboostEasioGdetailPtask_io_service4n0CQdev_poll_reactor4b___Gdo_one6Mrn0CLscoped_lock4n0CLposix_mutex___pn0EQidle_thread_info_rn0AGsystemKerror_code__I_+0x204 strandtest`__1cFboostEasioGdetailPtask_io_service4n0CQdev_poll_reactor4b___Drun6Mrn0AGsystemKerror_code__I_+0xa8 strandtest`main+0xe8 This one counts the system calls. What's very disturbing is that the longer you let it run the more sys calls are made. Why doesn't the system block waiting for the socket to become write-able again (which it won't)? dtrace -n 'syscall:::entry/pid == $target/ { @num[probefunc] = count(); }' -c $XX fcntl 6 brk 2474 sendmsg 21505 ioctl 60194 write 60195 lwp_sigmask 120382 Similar testing on Linux(x86) using strace doesn't show so many system calls (except a few for locking mutexes). Perhaps Christopher Kohlhoff or whoever implemented the thing can take a look. I'm guessing there some event which keeps getting detected but isn't processed. Would someone please take a look or do I need to debug it myself?

1 0

POD 3d vectors
by gtsml owevwr 04 Jun '09

04 Jun '09

Hi, I need fast low dimensional vector (2, 3 and 4 dimension let say). How shall I implement them with boost? Off course ublas is a possibility but I feel it's more designed for higher dimension. Ideally, low dimension vector are better as POD, without any pointer indirection for instance. Maybe there's a way to enforce no indirection with ublas? Off course, boost::array would do the trick but it doesn't have any of the basic arithmetic operators. I could easily add them with the operators library, but maybe there's a better way? And off course, could be great to have POD small matrices as well... I know this request is probably over specialized but maybe I'm missing something already there Thanks, Frank

8 7

[asio] thread-safe async_write with streambuf
by Rutger ter Borg 04 Jun '09

04 Jun '09

Hi all, I'm looking into thread-safe writing of data using Asio, using a streambuf. My current implementation boils down to something like the following. // posting Something from >1 thread(s) void async_send( Something s ) { m_strand.post( async_send_something(s) ); } // Serialized execution // Protects resources socket and streambuf void async_send_something( Something s) { std::ostream os( &m_streambuf ); os << s << std::flush; asio::async_write( m_socket, m_streambuf, transfer_all(), bind( async_complete ) ); } void async_complete( error e ) { } My main confusion is on how to do this with a streambuf. What happens between async_write and the completion handler? It could be that async_send_something is called from one thread before a completion handler of an earlier operation finishes in another thread, and in that case, I'm not sure if it is defined what happens with the streambuf. For the situation sketched above, I couldn't find guarantees around the access pattern of other io_service threads, so my question would be if the implementation above is really thread-safe, and if not, how to best achieve that. Thanks, Kind regards, Rutger

1 0

Using different variables based on template type
by Ryan McConnehey 04 Jun '09

04 Jun '09

I have a couple of functions that provide the same functionality for different types. I'd like to combine them to reduce code duplication. An example of two functions is listed below. std::map<std::string, uint16> m_Uint16; std::map<std::string, uint32> m_Uint32; void putUint16(std::string const& variableName, uint16 const& value) { m_Uint16[variableName] = value; } void putUint32(std::string const& variableName, uint32 const& value) { m_Uint32[variableName] = value; } The functions can't be combined into a template since they are the interface for the programmer. Is there a boost library that would let me call a template or common function that would use a different variable based on the variable type? Ryan

4 13

[string_algo] replace string with tokens
by Michael Schuster 03 Jun '09

03 Jun '09

Hello, I'm new to string_algo and have the following problem: I have string like a+3*sin(b) and want to replace a by a different string e.g. Alpha and b by Beta and sin by cos so that Alpha+3*cos(Beta) is the result. So tokens would be "+*()" The replace command works with spaces, but I think this should be possible with string_algo, too? Thanks for any hint Michael Schuster

3 2

[BGL] A bug in const bundle_property_map or in Readable Property Map Concept ?
by Dmitry Bufistov 03 Jun '09

03 Jun '09

Hi there, The attached test case fails to compile. If it is a bug I would be happy to open a ticket for it! Could somebody please confirm? Thank you, Dmitry

3 5

[exception] What's wrong with boost::get_error_info?
by Markus Schweiß 03 Jun '09

03 Jun '09

Dear boost community, I'm really new to using the boost library. Whatever, the first part I want to use is boost::exception. But already there start my problems: I'm using 'boost::get_error_info<boost::throw_file>( myBoostException )' to retrieve the file name where my exception was thrown. The problem is that the returned 'const char*' pointer contains several wild characters at its end. It seems that the null-termination get lost somehow, somewhere. The same is with 'boost::throw_function' and the string returned by 'boost::diagnostic_information( myBoostException )'! For example, that is what I get from boost::diagnostic_information: ".\myFile.cppÍýýýý««««««««îþ(134): Throw in function MyClass::DoSomething()ÍÍÍÍÍÍ^ñ6 Dynamic exception type: class MyBoostException" That's really strange because the strings are correctly stored to the boost::exception class attributes 'throw_function_' and 'throw_file_'. So what do I wrong??? I would be so thankful when anyone could help me! Following some detailed information: - plattfrom: Windows XP SP3 - compiler: MS VC++ 8 - character set: multi-byte - boost version: Release 1.37.0 code snippet for throwing my exception: throw MyBoostException() << boost::throw_file( __FILE__ ) << boost::throw_line( __LINE__ ) << boost::throw_function( "MyClass::DoSomething()" ); code snippet for catching my exception: catch( MyBoostException& myBoostException ) { std::string info = boost::diagnostic_information( myBoostException ); const char* string = info.c_str(); } My best regards, Markus

2 5

[Program Options]
by Björn Pollex 03 Jun '09

03 Jun '09

Hi everyone ! Is there a simple way to make the command line parser throw an error when an option is not specified ? This way i would not have to check this in my code. My program requires the user to specify an input file, and if he doesn't, an error should be displayed. So, is there any support for mandatory parameters (they wouldn't really be options if they are mandatory) ? wbr Bjoern Pollex

2 1

[ASIO] Where to use CoInitizeEx
by Daniele Barzotti 03 Jun '09

03 Jun '09

Hi, in a library I have a factory function that creates objects: ---- Main Library File ---- // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptr<boost::thread> io_service_thread; static boost::asio::io_service::work* p_work; static BOOL thread_started; EXTERN_C EUROATLIB_API TETRAMotoHndl CALL GetTETRAMotoObj() { if (!thread_started) { try { // create the work object on the heap p_work = new boost::asio::io_service::work(io_service); // run the IO service as a separate thread io_service_thread.reset( new boost::thread( boost::bind(&boost::asio::io_service::run, &io_service) ) ); thread_started = !thread_started; } catch (boost::thread_resource_error e) { // Failed to create the new thread return 0; } } // create the new object TETRAMoto* pTETRAMoto = new TETRAMoto(io_service); // Assign a reference to io_service work object: // This reference is used to counting the objects created. // When the last TETRAMoto object is deleted the main work object // is destroyed and the io_service thread ends. pTETRAMoto->_io_work_ptr.reset(p_work); // return the object return pTETRAMoto; }; --------------------------------- These TETRAMoto objects creates another object, ATDispatcher, that use a SerialPort (which is a wrapper around asio::serial_port) to continuously read and write to RS232. When the SerialPort receive data, pass it to the ATDispatcher that raises a signal to the TETRAMoto object that parses the data and raise the event (always a signal) to the extern: asio::serial_port -> SerialPort -> ATDispatcher -> TetraMoto -|-> EXTERN Now I have to encapsulate this lib into an ActiveX DLL to be used by VB6 and I have to call CoInitizeEx in the thread that "raise" events.. My question is: where I have to call CoInitizeEx? Thanks in advance, Daniele.

5 14

Bug Sprint Report for Tuesday, June 2nd
by Marshall Clow 03 Jun '09

03 Jun '09

The boost bug sprint started Friday, May 29th, and runs through Sunday June 7th. We slowed down a lot on Tuesday - let's pick it up again. Status <https://svn.boost.org/trac/boost/report/1> 7:00 AM PDT 5/29: 797 open tickets. 7:45 AM PDT 5/30: 772 open tickets. 6:00 AM PDT 5/31: 761 open tickets. 6:00 AM PDT 6/2: 747 open tickets. 6:00 AM PDT 6/3: 748 open tickets. Activity: 5/29: 6 new tickets, 77 modifications, 25 tickets closed 5/30: 2 new tickets, 42 modifications, 17 tickets closed 5/31: 2 new tickets, 27 modifications, 8 tickets closed 6/1: 2 new tickets, 42 modifications, 17 tickets closed 6/2: 5 new tickets, 18 modifications, 5 tickets closed. [ Numbers may not add up because I am counting via two different methods, using data that is time-stamped in two different time zones. Also, tickets can be closed and reopened. ] What can you do? See <https://svn.boost.org/trac/boost/wiki/BugSprintJune2009> for details. I've added four new reports to the trac: Open ticket count by owner: <https://svn.boost.org/trac/boost/report/18> Open ticket count by component: <https://svn.boost.org/trac/boost/report/19> Open ticket count by ticket type: <https://svn.boost.org/trac/boost/report/20> Open ticket count by milestone: <https://svn.boost.org/trac/boost/report/21> There's been a lot of discussion on the list about tickets; and there are about a dozen patches that have been tested and are ready to be applied. If you're looking to help, you can look at some of the older bugs, say, the ones for Boost 1.36, and determine if they still apply. If they do, note that in the ticket. There are 35 tickets that are still open that are marked as "to be fixed in Boost 1.36" See <https://svn.boost.org/trac/boost/report/3> for a list of open tickets by milestone. --------- Sign-up sheet -------- The following people have committed to participate in the bug sprint. Please add you name here, along with what you can do. 1) Marshall Clow (coordination, Mac OS X characterization) 2) Beman Dawes (filesystem, system, timer) 3) Doug Gregor (function, graph, logic, mpi, numeric, property_map, signals) 4) "joel falcou" <joel.falcou(a)u-psud.fr> ( linux gcc testing/VC 2008 testing, patching) 5) Michael Caisse <boost(a)objectmodelingdesigns.com> (bug fixing) 6) Jeremiah Willcock <jewillco(a)osl.iu.edu> (will test and commit graph patches) 7) David Abrahams (iterator, python) 8) Sohail Somani (patches for g++ 4.2.4) 9) Steven Watanabe <watanabesj(a)gmail.com> (bug fixes, como) 10) vicente.botet" <vicente.botet(a)wanadoo.fr> 11) Stjepan Rajko <stjepan.rajko(a)gmail.com> (fusion) 12) Daniel Wallin (parameter, ...) -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

1 0

dynamic_bitset, bitset, etc
by Zachary Turner 02 Jun '09

02 Jun '09

I find that I frequently want a class that provides the capabilities of a boost::dynamic_bitset, but that i want to be able to load the values all at once from a huge block of binary data. The exact use case is that I'm reading block data off of a disk, and in most modern file systems there's a very large chunk of data at the beginning that is just a series of bits that specify whether or not particular blocks are allocated. So I issue an I/O to read a chunk of this bitmap, then I just want to tell the class "do a huge memcpy and use this block of data as your internal buffer". Or better yet, member functions that a) give direct access to the internal buffer and b) tell me how many bytes the internal buffer is, and c) let me resize the internal buffer to hold x bits. There's vector<bool>, std::bitset, boost::dynamic_bitset, and boost::bitset. I understand why vector<bool> can't support this, but is there some fundamental reason why this seemingly simple operation is not supported on any available implementation of a bit set anywhere? Or is it supported and I'm just overlooking the function necessary to do it? I see there's a constructor that takes a BlockIterator, but I want it to ultimately boil down to a memcpy, not a for loop.

1 0

[BGL] read_graphml fails at compilation but MutableGraph concept test succeeds
by Paul Hilbert 02 Jun '09

02 Jun '09

Look at this (shortened) code fragment: namespace boost { ... Node* add_vertex(HalfedgeGraph& g) { Node* n = new Node(); g.AddNode(n); return n; } ... } int main(int argc, char* argv[]) { // #1 boost::function_requires< boost::MutableGraphConcept<HalfedgeGraph> >(); std::ifstream ifile("test_input.xml"); boost::dynamic_properties dp; HalfedgeGraph g; // #2 boost::read_graphml(ifile, g, dp); return 0; } The concept test at #1 (calling Node* add_vertex(HalfedgeGraph&)) succeeds (if I remove or alter the add_vertex function it fails as expected), but the read_graphml function at #2 doesn't compile telling me that add_vertex(HalfedgeGraph&) isn't compiled. How come the partial graph_traits specialization works for the concept-test-class but not for the graphml reader? (The HalfedgeGraph class did prove correct in the past and the graph_traits<HalfedgeGraph>::vertex_descriptor is a typedef for Node*) Greetings, Paul Hilbert

2 1

Bug Sprint Report for Monday, June 1st
by Marshall Clow 02 Jun '09

02 Jun '09

The boost bug sprint started Friday, May 29th, and runs through Sunday June 7th. Monday was a good day - lets keep it up! Status <https://svn.boost.org/trac/boost/report/1> 7:00 AM PDT 5/29: 797 open tickets. 7:45 AM PDT 5/30: 772 open tickets. 6:00 AM PDT 5/31: 761 open tickets. 6:00 AM PDT 6/2: 747 open tickets. Activity: 5/29: 6 new tickets, 77 modifications, 25 tickets closed 5/30: 2 new tickets, 42 modifications, 17 tickets closed 5/31: 2 new tickets, 27 modifications, 8 tickets closed 6/1: 2 new tickets, 42 modifications, 17 tickets closed [ Numbers may not add up because I am counting via two different methods, using data that is time-stamped in two different time zones. Also, tickets can be closed and reopened. ] What can you do? See <https://svn.boost.org/trac/boost/wiki/BugSprintJune2009> for details. I've added four new reports to the trac: Open ticket count by owner: <https://svn.boost.org/trac/boost/report/18> Open ticket count by component: <https://svn.boost.org/trac/boost/report/19> Open ticket count by ticket type: <https://svn.boost.org/trac/boost/report/20> Open ticket count by milestone: <https://svn.boost.org/trac/boost/report/21> There's been a lot of discussion on the list about tickets; and there are about a dozen patches that have been tested and are ready to be applied. If you're looking to help, you can look at some of the older bugs, say, the ones for Boost 1.36, and determine if they still apply. If they do, note that in the ticket. --------- Sign-up sheet -------- The following people have committed to participate in the bug sprint. Please add you name here, along with what you can do. 1) Marshall Clow (coordination, Mac OS X characterization) 2) Beman Dawes (filesystem, system, timer) 3) Doug Gregor (function, graph, logic, mpi, numeric, property_map, signals) 4) "joel falcou" <joel.falcou(a)u-psud.fr> ( linux gcc testing/VC 2008 testing, patching) 5) Michael Caisse <boost(a)objectmodelingdesigns.com> (bug fixing) 6) Jeremiah Willcock <jewillco(a)osl.iu.edu> (will test and commit graph patches) 7) David Abrahams (iterator, python) 8) Sohail Somani (patches for g++ 4.2.4) 9) Steven Watanabe <watanabesj(a)gmail.com> (bug fixes, como) 10) vicente.botet" <vicente.botet(a)wanadoo.fr> 11) Stjepan Rajko <stjepan.rajko(a)gmail.com> (fusion) 12) Daniel Wallin (parameter, ...) -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

1 0

Review Wizard Status Report for June 2009
by Ronald Garcia 02 Jun '09

02 Jun '09

============================================== Review Wizard Status Report for June 2009 ============================================== News ==== Futures: Williams variant Accepted; Gaskill variant Rejected Boost 1.38 Released New Libraries: Revised Libraries: Boost.Range Extension Accepted Polynomial Library Rejected Boost 1.39 Released Constrained Value Review - Review Result Pending Older Issues ============ The Time Series Library, accepted in August 2007, has not yet been submitted to SVN. Eric Niebler and John Phillips are working on making the changes suggested during the review. The Floating Point Utilities Library, has not yet been submitted to SVN. It is slated to be integrated with the Boost.Math library. The Switch Library, accepted provisionally in January 2008, has not yet been submitted for mini-review and full acceptance. The Phoenix Library, accepted provisionally in September 2008, has not yet been submitted for mini-review and full acceptance. A rewrite of Phoenix, basing it on the Proto metaprogramming library, has just begun. General Announcements ===================== As always, we need experienced review managers. The review queue has been growing substantially but we have had few volunteers, so manage reviews if possible and if not please make sure to watch the review schedule and participate. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants or library contributors. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "garcia at osl dot iu dot edu" and "phillips at mps dot ohio-state dot edu" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. A recent effort is trying to secure at least five people who promise to submit reviews as a precondition to starting the review period. Consider volunteering for this and even taking the time to create the review as early as possible. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report before we do that, please email Ron or John. If you're a library author and plan on submitting a library for review in the next 3-6 months, send Ron or John a short description of your library and we'll add it to the Libraries Under Construction below. We know that there are many libraries that are near completion, but we have hard time keeping track all of them. Please keep us informed about your progress. Review Queue ============ * Lexer * Shifted Pointer * Logging * Log * Join * Pimpl * Thread Pool * Endian * Meta State Machine * Conversion * Sorting * GIL.IO * AutoBuffer * String Convert -------------------- Lexer ----- :Author: Ben Hanson :Review Manager: Eric Neibler :Download: `Boost Vault <http://boost-consulting.com/vault/index.php?action=downloadfile&filename=bo… >`__ :Description: A programmable lexical analyser generator inspired by 'flex'. Like flex, it is programmed by the use of regular expressions and outputs a state machine as a number of DFAs utilising equivalence classes for compression. Shifted Pointer --------------- :Author: Phil Bouchard :Review Manager: Needed :Download: `Boost Vault <http://www.boost-consulting.com/vault/index.php?&direction=0&order=&directo… >`__ :Description: Smart pointers are in general optimized for a specific resource (memory usage, CPU cycles, user friendliness, ...) depending on what the user need to make the most of. The purpose of this smart pointer is mainly to allocate the reference counter (or owner) and the object itself at the same time so that dynamic memory management is simplified thus accelerated and cheaper on the memory map. Logging ------- :Author: John Torjo :Review Manager: Gennadiy Rozental :Download: http://torjo.com/log2/ :Description: Used properly, logging is a very powerful tool. Besides aiding debugging/testing, it can also show you how your application is used. The Boost Logging Library allows just for that, supporting a lot of scenarios, ranging from very simple (dumping all to one destination), to very complex (multiple logs, some enabled/some not, levels, etc). It features a very simple and flexible interface, efficient filtering of messages, thread-safety, formatters and destinations, easy manipulation of logs, finding the best logger/filter classes based on your application's needs, you can define your own macros and much more! Log --- :Author: Andrey Semashev :Review Manager: Needed :Download: `Boost Vault <http://tinyurl.com/cm9lum>`__ :Description: The library is aimed to help adding logging features to applications. It provides out-of-box support for many widely used capabilities, such as formatting and filtering based on attributes, sending logs to a syslog server or to Windows Event Log, or simply storing logs into files. It also provides basic support for the library initialization from a settings file. The library can also be used for a wider range of tasks and implement gathering and processing statistical information or notifying user about application events. Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Pimpl ----- :Author: Vladimir Batov :Review Manager: Needed :Download: | `Boost Vault <http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… >`__ | http://www.ddj.com/cpp/205918714 (documentation) :Description: The Pimpl idiom is a simple yet robust technique to minimize coupling via the separation of interface and implementation and then implementation hiding. This library provides a convenient yet flexible and generic deployment technique for the Pimpl idiom. It's seemingly complete and broadly applicable, yet minimal, simple and pleasant to use. Thread Pool ----------- :Author: Oliver Kowalke :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo… >`__ :Description: The library provides: - thread creation policies: determines the management of worker threads: - fixed set of threads in pool - create workerthreads on demand (depending on context) - let worker threads ime out after certain idle time - channel policies: manages access to queued tasks: - bounded channel with high and low watermark for queuing tasks - unbounded channel with unlimited number of queued tasks - rendezvous syncron hand-over between producer and consumer threads - queueing policy: determines how tasks will be removed from channel: - FIFO - LIFO - priority queue (attribute assigned to task) - smart insertions and extractions (for instance remove oldest task with certain attribute by newst one) - tasks can be chained and lazy submit of taks is also supported (thanks to Braddocks future library). - returns a task object from the submit function. The task it self can be interrupted if its is cooperative (means it has some interruption points in its code -> ``this_thread::interruption_point()`` ). Endian ------ :Author: Beman Dawes :Review Manager: Needed :Download: http://mysite.verizon.net/beman/endian-0.10.zip :Description: Header boost/integer/endian.hpp provides integer-like byte-holder binary types with explicit control over byte order, value type, size, and alignment. Typedefs provide easy-to-use names for common configurations. These types provide portable byte-holders for integer data, independent of particular computer architectures. Use cases almost always involve I/O, either via files or network connections. Although data portability is the primary motivation, these integer byte- holders may also be used to reduce memory use, file size, or network activity since they provide binary integer sizes not otherwise available. Meta State Machine ------------------ :Author: Christophe Henry :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?direction=0&order=&director… >`__ :Description: Msm is a framework which enables you to build a Finite State Machine in a straightforward, descriptive and easy-to-use manner . It requires minimal effort to generate a working program from an UML state machine diagram. This work was inspired by the state machine described in the book of David Abrahams and Aleksey Gurtovoy "C++ Template Metaprogramming" and adds most of what UML Designers are expecting from an UML State Machine framework: * Entry and Exit Methods * Guard Conditions * Sub state machines (also called composite states in UML) * History * Terminate Pseudo-State * Deferred Events * Orthogonal zones * Explicit entry into sub state machine states * Fork * Entry / Exit pseudo states * Conflicting transitions Conversion ---------- :Author: Vicente Botet :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=co… >`__ :Description: Generic explicit conversion between unrelated types. Boost.Conversion provides: * a generic ``convert_to`` function which can be specialized by the user to make explicit conversion between unrelated types. * a generic ``assign_to`` function which can be specialized by the user to make explicit assignation between unrelated types. * conversion between ``std::complex`` of explicitly convertible types. * conversion between ``std::pair`` of explicitly convertible types. * conversion between ``boost::optional`` of explicitly convertible types. * conversion between ``boost::rational`` of explicitly convertible types. * conversion between ``boost::interval`` of explicitly convertible types. * conversion between ``boost::chrono::time_point`` and ``boost::ptime``. * conversion between ``boost::chrono::duration`` and ``boost::time_duration``. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=al… >`__ :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 8X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 7X as fast as std::sort on x86 processors. string_sort is roughly 2X as fast as std::sort. GIL.IO ------ :Author: Christian Henning :Review Manager: Needed :Download: `GIL Google Code Vault <http://gil-contributions.googlecode.com/files/rc2.zip >`__ :Description: I/O extension for ``boost::gil`` which allows reading and writing of/in various image formats ( tiff, jpeg, png, etc ). This review will also include the Toolbox extension which adds some common functionality to gil, such as new color spaces, algorithms, etc. AutoBuffer ---------- :Author: Thorsten Ottosen :Review Manager: Needed :Download: `Here <http://www.cs.aau.dk/~nesotto/boost/ auto_buffer.zip>`__ :Description: Boost.AutoBuffer provides a container for efficient dynamic, local buffers. Furthermore, the container may be used as an alternative to std::vector, offering greater flexibility and sometimes better performance. String Convert -------------- :Author: Vladimir Batov :Review Manager: Needed :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=bo… >`__ :Description: The library takes the approach of boost::lexical_cast in the area of string-to-type and type-to-string conversions, builds on the past boost::lexical_cast experience and advances that conversion functionality further to additionally provide: * throwing and non-throwing conversion-failure behavior; * support for the default value to be returned when conversion fails; * two types of the conversion-failure check -- basic and better/safe; * formatting support based on the standard I/O Streams and the standard (or user-defined) I/O Stream-based manipulators (like std::hex, std::scientific, etc.); * locale support; * support for boost::range-compliant char and wchar_t-based string containers; * no DefaultConstructibility requirement for the Target type; * consistent framework to uniformly incorporate any type-to-type conversions. It is an essential tool with applications making extensive use of configuration files or having to process/prepare considerable amounts of data in, say, XML, etc. Libraries under development =========================== Please let us know of any libraries you are currently developing that you intend to submit for review. Mirror ------ :Author: Matus Chochlik :Download: | http://svn.boost.org/svn/boost/sandbox/mirror/doc/index.html | `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=mi… >`__ :Description: The aim of the Mirror library is to provide useful meta-data at both compile-time and run-time about common C++ constructs like namespaces, types, typedef-ined types, classes and their base classes and member attributes, instances, etc. and to provide generic interfaces for their introspection. Mirror is designed with the principle of stratification in mind and tries to be as less intrusive as possible. New or existing classes do not need to be designed to directly support Mirror and no Mirror related code is necessary in the class' definition, as far as some general guidelines are followed Most important features of the Mirror library that are currently implemented include: * Namespace-name inspection. * Inspection of the whole scope in which a namespace is defined * Type-name querying, with the support for typedef-ined typenames and typenames of derived types like pointers, references, cv-qualified types, arrays, functions and template names. Names with or without nested-name-specifiers can be queried. * Inspection of the scope in which a type has been defined * Uniform and generic inspection of class' base classes. One can inspect traits of the base classes for example their types, whether they are inherited virtually or not and the access specifier (private, protected, public). * Uniform and generic inspection of class' member attributes. At compile-time the count of class' attributes and their types, storage class specifiers (static, mutable) and some other traits can be queried. At run-time one can uniformly query the names and/or values (when given an instance of the reflected class) of the member attributes and sequentially execute a custom functor on every attribute of a class. * Traversals of a class' (or generally type's) structure with user defined visitors, which are optionally working on an provided instance of the type or just on it's structure without any run-time data. These visitors are guided by Mirror through the structure of the class and optionally provided with contextual information about the current position in the traversal. I'm hoping to have it review ready in the next few months. Interval Template Library ------------------------- :Author: Joachim Faulhaber :Description: The Interval Template Library (Itl) provides intervals and two kinds of interval containers: Interval_sets and interval_maps. Interval_sets and maps can be used just as sets or maps of elements. Yet they are much more space and time efficient when the elements occur in contiguous chunks: intervals. This is obviously the case in many problem domains, particularly in fields that deal with problems related to date and time. Interval containers allow for intersection with interval_sets to work with segmentation. For instance you might want to intersect an interval container with a grid of months and then iterate over those months. Finally interval_maps provide aggregation on associated values, if added intervals overlap with intervals that are stored in the interval_map. This feature is called aggregate on overlap. It is shown by example: :: typedef set<string> guests; interval_map<time, guests> party; guests mary; mary.insert("Mary"); guests harry; harry.insert("Harry"); party += make_pair(interval<time>::rightopen(20:00, 22:00),mary); party += make_pair(interval<time>::rightopen_(21:00, 23:00),harry); // party now contains [20:00, 21:00)->{"Mary"} [21:00, 22:00)->{"Harry","Mary"} //guest sets aggregated on overlap [22:00, 23:00)->{"Harry"} As can be seen from the example an interval_map has both a decompositional behavior (on the time dimension) as well as a accumulative one (on the associated values). StlConstantTimeSize ------------------- :Author: Vicente J. Botet Escriba :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=consta… >`__ :Description: Boost.StlConstantTimeSize Defines a wrapper to the stl container list giving the user the chioice for the complexity of the size function: linear time, constant time or quasi-constant. In future versions the library could include a similar wrapper to slist. InterThreads ------------------- :Author: Vicente J. Botet Escriba :Download: `Boost Vault <http://www.boostpro.com/vault/index.php?action=downloadfile&filename=in… >`__ :Description: Boost.InterThreads extends Boost.Threads adding some features: * thread decorator: thread_decorator allows to define setup/cleanup functions which will be called only once by thread: setup before the thread function and cleanup at thread exit. * thread specific shared pointer: this is an extension of the thread_specific_ptr providing access to this thread specific context from other threads. As it is shared the stored pointer is a shared_ptr instead of a raw one. * thread keep alive mechanism: this mechanism allows to detect threads that do not prove that they are alive by calling to the keep_alive_point regularly. When a thread is declared dead a user provided function is called, which by default will abort the program. * thread tuple: defines a thread groupe where the number of threads is know statically and the threads are created at construction time. * set_once: a synchonizer that allows to set a variable only once, notifying to the variable value to whatever is waiting for that. * thread_tuple_once: an extension of the boost::thread_tuple which allows to join the thread finishing the first, using for that the set_once synchronizer. * thread_group_once: an extension of the boost::thread_group which allows to join the thread finishing the first, using for that the set_once synchronizer. (thread_decorator and thread_specific_shared_ptr) are based on the original implementation of threadalert written by Roland Schwarz. Boost.InterThreads extends Boost.Threads adding thread setup/cleanup decorator, thread specific shared pointer, thread keep alive mechanism and thread tuples.

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[BGL]: How to delete whole sub-graph (tree in my case) ?
by Sachin Gaikwad 02 Jun '09

02 Jun '09

Hi all, I have a graph which is a tree actually. I need to delete the whole subtree given a vertex. Is there any interface to delete the whole subtree given the vertex ? or else, I will have to write a routine which does DFS and deletes each vertex/edge. Correct me if I am wrong: If I do clear_vertex(vertex_to_be_deleted, g) remove_vertex(vertex_to_be_deleted, g) I wont achieve what I want and I will get 2 disconnected graphs ? Thanks, Sachin

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Boost.Asio extensible to non network i/o?
by Zachary Turner 01 Jun '09

01 Jun '09

I've been reading over the documentation for Boost.Asio and as far as I can tell the documentation makes no mention whatsoever about using Asio for anything other than sockets programming. Suppose I wanted to implemented a simple file transfer client (I say client because the server will not be in C++) that reads files off of the disk and sends them to the server. I'd like to do it asynchronously. What would be the basic steps needed to do this with Boost.Asio, if it is indeed even possible? I'd specifically like it to use I/O Completion Ports on Windows if possible, and whatever on Linux. I'd like to be able to configure the number of worker threads on the backend, so that for example I can read from N files at once, or from N different locations in the same file. I'd also like to have a single "controller" thread that receives all the events regarding when reads or writes complete, so that I don't have to use any kind of locking to synchronize things. As a final "nice-to-have", I'd like to be able to plug my own types of "actions" into the model, things that aren't really I/O but that I still want to execute asynchronously that would sit in between a completed disk read and the initiation of writing that same data to the socket. Think, for example, of encrypting the file before sending. I don't want to block on the encryption, so it would be nice if I could do that asynchronously and still be notified of its completion through the same interface. I know I can do all this directly in windows (which is the only system api i'm intimately familiar with) via IOCP, so I'm hoping something similar can be achieved with Boost.Asio. Thanks

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Bug Sprint Report for Sunday, May 31st
by Marshall Clow 01 Jun '09

01 Jun '09

The boost bug sprint started Friday, May 29th, and runs through Sunday June 7th. Well, we've slowed down some, but we're still making progress. Status <https://svn.boost.org/trac/boost/report/1> 7:00 AM PDT 5/29: 797 open tickets. 7:45 AM PDT 5/30: 772 open tickets. 6:00 AM PDT 5/31: 761 open tickets. Activity: 5/29: 6 new tickets, 77 modifications, 25 tickets closed 5/30: 2 new tickets, 42 modifications, 17 tickets closed 5/31: 2 new tickets, 27 modifications, 8 tickets closed [ Numbers may not add up because I am counting via two different methods, using data that is time-stamped in two different time zones. Also, tickets can be closed and reopened. ] What can you do? See <https://svn.boost.org/trac/boost/wiki/BugSprintJune2009> for details. I've added four new reports to the trac: Open ticket count by owner: <https://svn.boost.org/trac/boost/report/18> Open ticket count by component: <https://svn.boost.org/trac/boost/report/19> Open ticket count by ticket type: <https://svn.boost.org/trac/boost/report/20> Open ticket count by milestone: <https://svn.boost.org/trac/boost/report/21> There's been a lot of discussion on the list about tickets; and there are about a dozen patches that have been tested and are ready to be applied. If you're looking to help, you can look at some of the older bugs, say, the ones for Boost 1.36, and determine if they still apply. If they do, note that in the ticket. --------- Sign-up sheet -------- The following people have committed to participate in the bug sprint. Please add you name here, along with what you can do. 1) Marshall Clow (coordination, Mac OS X characterization) 2) Beman Dawes (filesystem, system, timer) 3) Doug Gregor (function, graph, logic, mpi, numeric, property_map, signals) 4) "joel falcou" <joel.falcou(a)u-psud.fr> ( linux gcc testing/VC 2008 testing, patching) 5) Michael Caisse <boost(a)objectmodelingdesigns.com> (bug fixing) 6) Jeremiah Willcock <jewillco(a)osl.iu.edu> (will test and commit graph patches) 7) David Abrahams (iterator, python) 8) Sohail Somani (patches for g++ 4.2.4) 9) Steven Watanabe <watanabesj(a)gmail.com> (bug fixes, como) 10) vicente.botet" <vicente.botet(a)wanadoo.fr> 11) Stjepan Rajko <stjepan.rajko(a)gmail.com> (fusion) 12) Daniel Wallin (parameter, ...) -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

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Can I create Mfc Dialog from boost thread ?
by elizabeta petreska 01 Jun '09

01 Jun '09

Hello all Is it allowed to create mfc dialog or windows api dialog from boost thread, and if not is there a way to do that? Thanks

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Boost.Process article: Tutorial and request for comments
by Boris Schaeling 01 Jun '09

01 Jun '09

I've written an article about Boost.Process: http://www.highscore.de/cpp/process/ I've also fixed a few bugs in Boost.Process (which is now 0.31): http://www.highscore.de/boost/process.zip And the latest source code can also be found in the sandbox: https://svn.boost.org/svn/boost/sandbox/process/ For developers not familar with Boost.Process the article is a tutorial to get more easily started. For developers familiar with Boost.Process it is a request for comments. I've been looking at the big picture finally trying to find out where and how Boost.Process should be changed and in which direction it should move to become a complete library one day. As not everyone will read the entire article here are my thoughts: 1) Boost.Process is based on a few concepts like 'process' and 'context'. While those make sense there are other concepts where I wonder if they should be dropped: * 'executable' is the executable name which in practice must be a std::string. I think the original idea was to support numerous string types. This leads to the question how to support different Unicode encodings which I think is still unanswered in the Boost community. Other libraries, eg. Boost.Interprocess, simply stick to one string type (typically std::string). * 'handle' is the underlying native file handle of a stream (file descriptor on POSIX systems, handle on Windows). The concept is based on a class in the detail namespace of Boost.Process. There is just one class and it's not meant to be used by users of the library either. Thus I'm not sure what's the benefit of having an explicit 'handle' concept at all. 2) Environment variables must be sorted on Windows but not on POSIX systems. On Windows the type environment could be a typedef for std::map and on POSIX systems for std::unordered_map. Currently it's always a typedef for std::map. Is that ok? Should it be changed? Should a macro be provided in case developers want to use different typedefs? 3) Currently Boost.Process is really only useful for creating child processes. It's not possible for example to detect and iterate over other processes on a system. I guess Boost.Process should be enhanced here. Then one day the well-known utility 'ps' on POSIX systems could be implemented in Boost C++. Any comments? 4) When a process is created the standard streams (stdin, stdout and stderr) are closed by default. Is this a good choice? If it isn't what should happen otherwise? Inherting standard streams (which is the default behavior with fork on POSIX systems)? 5) Boost.Process requires to specify an absolute path to an executable which should be started. There is a helper function which returns the absolute path for an executable name (it uses the environment variable PATH). The question is if this should be done automatically if no absolute path is given? 6) When a stream of a child process is captured Boost.Process automatically creates a pipe. As pipes don't support asynchronous operations on Windows a named pipe is required (called FIFO on POSIX systems). Currently a macro must be defined to make Boost.Process use a named pipe on Windows. It might make more sense to enable developers to choose either a pipe or a FIFO explicitly - not only on Windows but on all platforms. Any comments? 7) It's possible to capture and access streams of a child process. Those streams are derived from std::istream and std::ostream and thus only support blocking I/O operations. Currently the underlying handle has to be fetched to initialize a generic I/O object from Boost.Asio to use asynchronous I/O operations. How should the library be changed to make it easier to use asynchronous I/O? 8) There is a method wait() which makes it possible to wait for another process to exit. Currently wait() is provided by the class child though. Shouldn't it really be defined by the class process (so you can wait not only for child processes to exit)? 9) As wait() blocks an asynchronous alternative should be provided. 10) The Windows-specific classes all start with win32_ (eg. win32_child). Wouldn't it make more sense to use windows_ instead (like windows_child) or a windows namespace? First other libraries use windows_ (see Boost.Interprocess). Second there should be no reason why a class like win32_child can't be used on a 64-bit Windows. Boris

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indirect_iterator,symmetric_matrix and ptr_vector
by Archie14 01 Jun '09

01 Jun '09

Following test fails to compile. Errors start with the first call to make_indirect_iterator. On the first glace on the error output it looks that indirect_iterators cannot be used together with ptr_vector and matrix. Is that correct? If I need to calculate the sum of all matrices in a vector - what is the right way to do it? void test() { typedef symmetric_matrix<double, lower> matrixofdoubles; boost::ptr_vector<matrixofdoubles> lst; boost::make_indirect_iterator(lst.begin()); // testing ind.iter. matrixofdoubles totalsum (10); std::accumulate( boost::make_indirect_iterator(lst.begin()), boost::make_indirect_iterator(lst.end()), totalsum, std::plus<matrixofdoubles>()); } Errors are: c:\Libraries\boost\boost_1_39_0\boost/pointee.hpp(30) : error C2039: 'element_type' : is not a member of 'boost::numeric::ublas::symmetric_matrix<T,TRI>' with [ T=double, TRI=boost::numeric::ublas::lower ] c:\Libraries\boost\boost_1_39_0\boost/mpl/eval_if.hpp(41) : see reference to class template instantiation 'boost::detail::smart_ptr_pointee<P>' being compiled with [ P=boost::numeric::ublas::symmetric_matrix<double,boost::numeric::ublas::lower> ] c:\Libraries\boost\boost_1_39_0\boost/pointee.hpp(69) : see reference to class template instantiation 'boost::mpl::eval_if<C,F1,F2>' being compiled with [ C=boost::detail::is_incrementable<boost::numeric::ublas::symmetric_matrix<doubl e,boost::numeric::ublas::lower>>, F1=boost::detail::iterator_pointee<boost::numeric::ublas::symmetric_matrix<doub le,boost::numeric::ublas::lower>>, .. etc.

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google.stringencoders vs (boost.string_algo & boost.lexical_cast)
by Roman Shmelev 01 Jun '09

01 Jun '09

Hi! stringencoders are told to be 2x faster than std approaches. But what about boost? Has somebody tested the performance of both libraries? I mean toLower, toUpper, itoa, dtoa functions. Thank you

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multi_array_ref (lack of) default constructor
by gtsml owevwr 01 Jun '09

01 Jun '09

Hi, Does anybody know why multi_array_ref doesn't have a default constructor? I'm asking because I wanted to make a multi_array of multi_array_ref and that doesn't seem to be possible because multi_array expect the element type to be default constructible. Thanks, Frank

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Re: [Boost-users] boost::serialization and PHP websites
by Brian Wood 01 Jun '09

01 Jun '09

Pascal Kesseli writes: > Currently, I consider the > boost serialization a de-facto standard for C++ serialization issues. In 2007 it wasn't a stretch to say that General Motors was a de facto standard in the automobile industry. Now they want 70 billion from taxpayers. Oh my G-d! -- Brian Wood Ebenezer Enterprises www.webEbenezer.net "Then Samuel took a rock and set it up between Mizpah and Shen. He named it Ebenezer [Rock of Help] and said, 'Until now the L-RD has helped us.'"

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Vector types in dynamic_properties used by write_graphml
by Richard Vock 31 May '09

31 May '09

He Folks, I'm using bundled properties in order to attach multiple attributes to graph nodes. Using only basic data types like integers, strings etc. the following example code works well. However I would like to also use vectors or similar containers (like in the example about bundled properties at http://www.boost.org/doc/libs/1_39_0/libs/graph/doc/bundles.html) However I don't know how to use this field for my dynamic_property map. In the following code the single commented-out line is the point where I most probably didn't understand some kind of vital concept. Maybe you could enlighten me or at least point me in the right direction, thanks in advance Richard Vock --- Here's the example code: #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/dynamic_property_map.hpp> #include <boost/graph/graphml.hpp> struct NodeProperties { int test; std::vector<int> ints; }; int main(int argc, char* argv[]) { typedef std::pair<int,int> Edge; std::vector< Edge > connections; // create simple edge loop for testing purposes for (int i=0; i<10; ++i) connections.push_back( Edge(i,(i+1)%10) ); typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::undirectedS, NodeProperties> Graph; Graph g(connections.begin(), connections.end(), 10); boost::graph_traits<Graph>::vertex_iterator v, v_end; for (tie(v,v_end) = vertices(g); v != v_end; ++v) { Graph::vertex_descriptor desc = *v; g[desc].test = 10; for (int i=0; i<5; ++i) g[desc].ints.push_back(i); } boost::dynamic_properties dp; dp.property("test", get(&NodeProperties::test, g)); //dp.property("testInts", get(&NodeProperties::ints, g)); boost::write_graphml(std::cout, g, dp, true); }

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Re: [Boost-users] Bug Sprint Report for Friday, May 29th
by Daniel James 31 May '09

31 May '09

2009/5/30 Marshall Clow <marshall(a)idio.com>: > The following bugs appear to have been fixed, but the tickets were never > closed. > I would appreciate it if the library maintainers could verify this and close > the tickets. > https://svn.boost.org/trac/boost/ticket/145 Iterator Oh, I just closed this as it's certainly fixed. Then I realised that it might have been mentioned on the list and found this. > The following tickets are feature requests that are unlikely ever to be > implemented. > Should they be closed? > https://svn.boost.org/trac/boost/ticket/558 database This one should definitely be closed as 'wontfix'. It's too open ended. There's a better place for ignoring library requests: https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#LibrariesW… > https://svn.boost.org/trac/boost/ticket/100 concept_check > https://svn.boost.org/trac/boost/ticket/182 concept_check I'd close there as well. They're very open ended and nothing to do with concept check. The allocator request could possibly be requested for other libraries. Anyway, they're so old I can't imagine requester has probably given up by now. Daniel

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