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[Boost.smart_ptr] Thread Safety
by Thomas Jordan 07 Jan '12

07 Jan '12

Sorry, please ignore my previous post - finger trouble. The question is as follows: ------ Hi, Is shared_array completely thread-safe, including destruction/reference counting? From the code in /boost/detail/sp_counted_base_pt.hpp it looks like it probably is but according to http://www.boost.org/doc/libs/1_33_1/libs/smart_ptr/shared_ptr.htm#ThreadSa… // thread A p3 = p2; // reads p2, writes p3 // thread B // p2 goes out of scope: undefined, the destructor is considered a "write access" shared_ptr isn't completely thread-safe for simultaneous read and write/destruct access? The same would presumbly apply to shared_array? Maybe I've missed something, are there compile-time configuration options to determine level of safety? Regards, T.

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[Boost.Move] [Boost.Container] Compiling with older version of Boost and performance
by Thomas Jordan 07 Jan '12

07 Jan '12

Hi, I am interested in experimenting with v1.48 Boost.Move and Boost.Container. However, I am otherwise constrained to using Boost libraries v1.33.1 with a Sun C++ v5.10 compiler. I couldn't seem any 'Boost library dependencies' listed in the Move/Container documentation, but a quick look through the header files suggests that it is mainly MPL and Type Traits. So... First question: would it be feasible for me to combine the headers for these two libraries with the v1.33.1 libraries and get it to work (albeit maybe with a little customisation), or would it be a big job/non-starter? Second question - I don't see any performance analysis published for Boost.Move. I know that move semantics is about more than improved performance, but am interested in that side of things, especially as the above compiler appears suboptimal in terms of copy elision and RVO. I am wondering for example whether are there any (compiler-specific) factors which could mitigate against the performance benefits of doing a move vs a copy of a vector, using these libraries, for example. Regards, T.

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[Boost.smart_ptr] Thread Safety
by Thomas Jordan 07 Jan '12

07 Jan '12

Hi, Is shared_array completely thread-safe. including destruction/reference counting? http://www.boost.org/doc/libs/1_33_1/libs/smart_ptr/shared_ptr.htm#ThreadSa… // thread A p3 = p2; // reads p2, writes p3 // thread B // p2 goes out of scope: undefined, the destructor is considered a "write access" /bb/source/boost/boost_1_33_1/boost/detail/sp_counted_base_pt.hpp

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On the lack of manpower: (Apache stdcxx)
by Jim Bell 06 Jan '12

06 Jan '12

Though this isn't news, I just came across it and it speaks to our common problem. (And it's of interest to boost users in general.) Note that ARM and Sun are even invested in stdcxx to some extent. From Apache's C++ Standard Library project <http://stdcxx.apache.org/status/2011-02.txt>: Stdcxx continues to be dormant. All but [1] committer have moved on to other projects. The only remaining committer (the VP of the project) is too busy with his day job to make even small changes, or to put out the long-awaited patch release, stdcxx 4.2.2. A number of users and organizations have been using the project and expressed interest in contributing to it. Several submitted patches, others have offered help with the project build and test infrastructure. Unfortunately, since no committer is available to review patches and guide the contributors through the ASF process to enable them to gain commit privileges there seems to be little hope of reviving stdcxx. A possible solution that would allow contributions to resume is to grant commit privileges to the handful of contributors who have already submitted some patches or expressed serious interest in contributing going forward. Another alternative is to move stdcxx to a repository outside of ASF such as SPI (http://www.spi-inc.org/) where interested developers could start committing changes on their own right away, without going through the "training" process. This seems to the preferred solution among at least some of the interested users. Are there any other options? Future plans: Unless the issue with contributions can be resolved in the next quarter I suggest to retire the project.

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[Boost.Lambda] Some new features are suggested: return, iterating yield, & local var
by Huang Huan 06 Jan '12

06 Jan '12

Hi boosters, I'm intrested in Lambda, so I have worked out some new features, and suggest boost lib add them. What can I do next? NEW features: 1. return. why lambda lib do not include this? 2. generate iterator/iteration by lambda using yield return/yield break. 3. local/global var declare and using. 1. return e.g. boost::function<char(int)> f = ( if_ ( _1 >= 0 ) [ return_('a') ], return_('b') ); p.s. return should be supported. 2. iterator/iteration generation by lambda using yield return/yield break const char* p; // we shuld use the local var inside lambda instead of this var p. refer to section 3 iteration<char> it = ( for_(var(p) = _1, *var(p), var(p)++) [ if_(*var(p) != ' ') [ yield_return(*var(p)) ] if_(*var(p) == ';') [ yield_break() ] ] ) ("I love this game; no use"); p.s. The packing iteration interface is very like the yield keyword in C# IEnumeable 3.local/global var declare and using e.g. char a; var_name x, y, z; global_var<int>(y); // put this line inside lambda is ok, just before use it ( ( local_var<int>(x), // local var declare // global_var<int>(y), var(a) = 'a', var<int>(x) = _2, // using local var x ), ( local_var<char>(z), var(a), var<int>(x) = _1, // error! x is not local var here. var<int>(y), // ok for global even if another lambda var<char>(z) = 'b', ) ) p.s. Now, in my work. It's hard to simplify var<T>(x) to var(x). It's a hard template working.

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Re: [boost] [log] Status (was: Is there any interest in a Group of library like to Application System!)
by Andrey Semashev 06 Jan '12

06 Jan '12

On Wednesday, January 04, 2012 09:08:16 Renato Tegon Forti wrote: > Hi Andrey, > > Thanks for your response! What is status of your lib? Do you need any help? The library is moving slowly to v2 release. Right now I'm wrapping up bounded async frontends, I intend to finish them by the weekend. Other things left to be done before the release are: - Port filters and formatters to Phoenix v3. As a part of it, improve error messages in exceptions and make filters and formatters not throw by default. - Introduce "default" sink concept to mitigate problems with trivial and advanced logging coexistence. Trivial logging will no longer initialize the library under the hood. - Implement a common attribute registration mechanism to simplify library extension. This should solve problems with settings file parser not recognizing user-defined attribute types. - Update the documentation. There are many other things to be done but they are not showstoppers for the release. Yes, help would be much appreciated, most notably in the porting to Phoenix v3 part. If anyone is willing to help, please contact me privately or through this list.

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[Graph] Concept check VertexMutablePropertyGraph
by Jens Müller 05 Jan '12

05 Jan '12

Hi, http://www.boost.org/doc/libs/1_48_0/libs/graph/doc/MutablePropertyGraph.ht… (I cannot find docs for VertexMutablePropertyGraph or EdgeMutablePropertyGraph) says that the types boost::graph_traits<G>::vertex_property_type and boost::graph_traits<G>::edge_property_type must exist. However, the concept checks (in boost/graph/graph_concepts.hpp) check for vertex_property_type<G>::type and edge_property_type<G>::type, respectively. Several questions: 1. Should there be separate docs for VertexMutablePropertyGraph and EdgeMutablePropertyGraph? 2. Should there be an actual concept check implementation for MutablePropertyGraph combining the two? 3. Should the concept check look for boost::graph_traits<G>::vertex_property_type instead of ertex_property_type<G>::type? [and the same for edge] 4. For the LEDA adapter, i.e., external adaptation, do I have to specialize vertex_property_type<G> and edge_property_type<G>? Best, Jens

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[graph] VertexListGraph and InputIterator, and LEDA graph
by Jens Müller 05 Jan '12

05 Jan '12

Hi all, I'm currently fixing up leda_graph.hpp so it passes the tests, or indeed, fixing the tests ... A leda::GRAPH<int,int> (=Graph) has to fulfill VertexListGraphConcept. This means that boost::graph_traits<G>::vertex_iterator has to be a MultiPassInputIterator, i.e., also a InputIterator. I cannot read from http://www.sgi.com/tech/stl/InputIterator.html that it must be possible that you can compute the difference between two iterators. But apparently the concept check (which fails) requires a difference type, which must be a signed integer. Is this a bug in the concept check? The vertex_iterator type is defined in leda_graph.hpp using iterator_facade: class vertex_iterator : public iterator_facade<vertex_iterator, leda::node, bidirectional_traversal_tag, const leda::node&, const leda::node*> { public: vertex_iterator(leda::node node = 0, const leda::GRAPH<vtype, etype>* g = 0) : base(node), g(g) {} private: const leda::node& dereference() const { return base; } bool equal(const vertex_iterator& other) const { return base == other.base; } void increment() { base = g->succ_node(base); } void decrement() { base = g->pred_node(base); } leda::node base; const leda::GRAPH<vtype, etype>* g; friend class iterator_core_access; }; Is maybe iterator_facade insufficient? For me, bidirectional_traversal_tag does not indicate that random access is possible ... -- Jens

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[chrono] Possible bug in boost::chrono::process_real_cpu_clock::now() under Windows 32bits
by ivan.lelann＠free.fr 05 Jan '12

05 Jan '12

Hi, As of 1.48 Boost.Chrono contains code below for boost::chrono::process_real_cpu_clock::now() (boost\chrono\detail\inlined\win\process_cpu_clocks.hpp) clock_t c = ::clock(); /* ... */ return time_point( duration(c*(1000000000l/CLOCKS_PER_SEC)) ); duration::rep is int64/nanoseconds, clock_t is long. This is VS2008, Win XP 32bits. I think "c" should be cast to duration::rep before being multiplied. I randomly get negative time_point and this seems to be fixed by replacing "c" with "((duration::rep) (c))" in duration constructor : duration( ((duration::rep) (c)) *(1000000000l/CLOCKS_PER_SEC)) Can someone confirm my view and that the fix is correct ? Regards, Ivan

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Is there any interest in a library for Application System? (Request for comments)
by Renato Tegon Forti 05 Jan '12

05 Jan '12

Some detail (Brainstorm): This library will provide a simple way to create an application that can be: . A Server Application A server application usually starts when system boot, and then remain running as background process, don't matter who is currently logged. In Windows this will a "Windows Service" and in UNIX a "UNIX Daemon", and we can create a "Neutral Application" that is not a daemon and service, but uses "service interface" that will provide methods like an "init", "interrogate", "restart" and so on. Some type of "system global mutex" will be implemented in this flavor, then if user want, he can determine that only one instance of service will run in a system in same time. A web server, data base server and so on area examples. . A Usual Application A usual application is a normal application, that don't need all of features provided by "server application" usually is started by a user and run by a determined period. A command, mail client, MPI master/Slave and so on area examples. . Base Class Both classes will be derivated of environment class that will provide common thinks and proprieties like an "app path", "app name", "app work dir" and so on. For sample: A user that want create a server, extend your class of "server class" and then override methods that want to get needed behavior. // windows service, or daemon class myapp : public boost::application::server{}; // neutral server class myapp : public boost::application::server<neutral>{}; // usual application class myapp : public boost::application::app{}; Note that: 1) Application can be configured using Boost.Program_options 2) I want use Boost.Log to provide log functionality when available. 3) I want create a "service model" then I want use Boost.Extension to provide dynamically late bind extension (Pluf-in System). What Boosters think? This is useful or is fool lib? Boosters think that "this kind of lib" is very specific, and violate: "The library must be generally useful and not restricted to a narrow problem domain." or this kind of system is relevant to boost. Please let me know the correct way to follows! Please make suggestions! What more else? Thanks

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Copyright and authorship notices
by Jens Müller 05 Jan '12

05 Jan '12

Hi all, what is the policy of adding a Copyright notice and entries to the author list when patching existing files? I found http://www.boost.org/development/requirements.html#Ownership, but it is not completely helpful. -- Jens

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[thread] Boost.Thread defines boost::move which conflicts with Boost.Move
by Hartmut Kaiser 05 Jan '12

05 Jan '12

VC10, SVN trunk: #include <boost/move/move.hpp> #include <boost/thread.hpp> int main() { return 0; } Results in: .../boost/thread/detail/move.hpp(28) : error C2995: 'remove_reference<T>::type &&boost::move(T &&)' : function template has already been defined .../boost/move/move.hpp(466) : see declaration of 'boost::move' IMHO, Boost.Thread needs to be changed to rely on Boost.Move for move semantics instead of defining its own implementation for boost::move(). Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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Font used in the current Boost logo
by Mateusz Łoskot 04 Jan '12

04 Jan '12

Hi, I have tried to find what font is used in the Boost logo but without any luck. There seem to be no logo in vector format included in the trunk. The SVG file from the logo variants is not helpful: http://dbp-consulting.com/boostvariantslogo.html Does anyone know where to find the font or vector version of the logo? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[geometry] GGL mailing list moved
by Mateusz Loskot 04 Jan '12

04 Jan '12

Hi, To Whom It May Concern... The Boost.Geometry library mailing list has moved from ggl at lists.osgeo.org server to geometry at lists.boost.org server. All existing subscribers and archives have been moved to the new server. The new list is available at: http://lists.boost.org/mailman/listinfo.cgi/geometry as well as listed on the main page: http://lists.boost.org/ It is also mirrored at Nabble: http://boost-geometry.203548.n3.nabble.com/ (Mirror at gmane.org may be added in future.) The old list at lists.osgeo.org will be wiped out soon. If anyone experiences any problems with the new geometry at lists.boost.org, please contact me directly. I'd like to thank OSGeo Foundation for hosting the first mailing list and the Boost mailman admins for help with the new one. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Re: [boost] [Container] deque emplace() requirements
by Ion Gaztañaga 04 Jan '12

04 Jan '12

El 04/01/2012 12:50, Szymon Gatner escribió: > 2011/12/13 Ion Gaztañaga<igaztanaga(a)gmail.com>: >> >> You are right, it's a bug. I'll try to fix it when I get some time. >> > > Got a chance to take a look at this? I think it's fixed in trunk, you'll need to update Boost.Intrusive as well. Best, Ion

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Is there any interest in a Group of library like to Application System!
by Renato Tegon Forti 04 Jan '12

04 Jan '12

I am proposing before a Log library in model of Log4cxx, but my plan is provide a full application system that will have: * Log System (Log4cxx Model) * Application System (Windows Service, Unix Daemon and Usual Application) -> Process Management (I don't know?) * Plugin System (service model): dynamically late bind extension. This will provide modular functionality that can be loaded in applications. For sample a service that can be loaded in application container, or a skin loaded in Client (MP3) Application. To illustrate: A developer that need create a server application will do: 1) Extend for "boost::application::server" and in this it use boost::log. (here if app is a Win32 then it have a Windows Service, or a daemon in unix) 2) To create service (modular application) he extend of "boost::service" to create a service and plug this service in runtime on "boost::application::server". Note that: Application can be configured using Boost.Program_options for sample. We can use Boost.Log to log, or (I don't know) we can buid Log4 model on top of Boost.Log? What Boosters think? Boosters think that "this kind of lib" is very specific, and violate: "The library must be generally useful and not restricted to a narrow problem domain." or this kind of system is relevant to boost. Please let me know the correct way to follows! Anyone that want participate is welcome! Ps: Ps: We already have some discussion in "Log Lib" topic! Thanks

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Log Lib?
by Renato Tegon Forti 04 Jan '12

04 Jan '12

Is there any interest in a library to "Log" in model of Log4cxx? Thanks

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Log Lib!
by Renato Tegon Forti 03 Jan '12

03 Jan '12

Is there any interest in a library to "Log" in model of Log4cxx? Thanks

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[context review] Quick Review
by Stewart, Robert 03 Jan '12

03 Jan '12

Here's my quick review of the proposed Boost.Context library. I'm not familiar with the kernel-level machinations involved to save and restore the execution state managed by the context class, so I cannot comment on such implementation details and whether they satisfy the acceptance criteria. Consequently, I didn't bother to look at the implementation. The examples are good, but the discussion or comments are somewhat lacking. For example, the Enumerator example is based upon an enumerator class type which is not commented and has very little introductory text. There's a link to C# documentation on the yield keyword, but no association of enumerator's yield_return() to C#'s "yield return" statement or yield_break() to "yield break". Those associations can be inferred easily enough, but are better stated explicitly. The enumerator example is further confused by indicating that a call to yield_return() in the power derivate returns a value to the while loop in main(). What's missing is that yield_return() calls context::suspend() on enumerator's context data member which returns control to enumerator<T>::get(), which is called by main()'s while loop. The entire enumerator example should be introduced by discussing the power class first, without implementation details: class power { public: power(int _base, int _exponent); bool get(int & _value); }; Then, the example can show main(), since the above interface is sufficient. That done, the example can turn the reader's attention to how to implement power by referring to the C# yield documentation example and then relating it to Boost.Context. That will lead to the enumerator class. (Making enumerator a class template complicates matters more than necessary, BTW.) Finally, you should show expected output. I'd like to see a performance comparison of using Boost.Context versus Chris Kohlhoff's coroutines. Can his coroutines be replaced with yours without loss of efficiency? Would it require a different stack allocator to match the performance of his coroutines? (Developing the example in that direction would be useful to illustrate writing a custom stack allocator.) I don't find anything related to the Movable Stack concept suggested in the acceptance criteria. The documentation of the StackAllocator is lacking, but I've suggested a rewrite below. With that rewrite, I think it satisfies the Stack concept required for acceptance. There are no performance figures for Windows. Shouldn't there be? I think I recall that the build system doesn't support the necessary information, by default, to permit building an ABI compatible version of the library. If that's not the case, then the "How to build and install" section needs more work. Either way, the Build acceptance criteria has not quite been met yet. The _suggested_ callback-based linking was not adopted in lieu of fc_link. There should be some rationale or a FAQ for that. I've called for still more work on the documentation, but as it stands, with the concept changes I've suggested, I'm satisfied that Oliver has met the documentation acceptance criteria. _____________________________________________ Documentation comments follow. _______________ Overview This section is useful and clear, except for the second sentence of the third paragraph. It doesn't connect to the library in question as it ought and is worded a little unclearly. I'd suggest the following instead: "By contrast, transferring control within a single thread, as _context_ does, requires only a few hundred CPU cycles since it involves no system calls." You might also add something like, "which makes them useful in more contexts, particularly when implementing higher level execution control systems", to that sentence. What's missing is a Motivation section or more information in the Overview to better explain why someone would want to use Boost.Context versus other options (whatever they may be). _______________ How to build and install There should be an introductory paragraph, something like the following: "Boost.Context must be built for the particular compiler(s) and CPU architecture(s) being targeted. Each combination requires specific build command arguments as documented below." The bullets at the top of the page are only needed until the library is accepted, so be sure to remove them upon acceptance. "On POSIX and Windows systems, GNU AS and MASM are respectively required for the assembler implementation of Boost.Context" is awkward. I suggest the following instead: "Boost.Context includes assembly code and, therefore, requires GNU AS for supported POSIX systems, and MASM for Windows systems." The Note is a little awkward and includes a spelling error. I suggest the following instead: "The architecture, instruction set, and address model are optional Boost.Build properties that must be given on the bjam command line, as shown in the table below." _______________ Executing a context 3rd para: s/a function or callable object/a _context-function_/ 5th para: this should be merged with para 4 and "and might be changed" should be inside the parentheses or I don't understand how it "might be changed". 6th para, 4th sent: Add the following to the end: ", after saving the new state of the original context" 6th para, last sent: Is there anything that ensures start() is called first and only once? Example: - The control transfer comments in fn() could be a little clearer: // transfer execution control back to main() ... // execution control transferred back from main() - The first "main() calls context ctx" would be better as "main() starts context ctx" - The comment, "// ctx.suspend() was called", in the while loop is only accurate until the for loop, in fn(), terminates, right? - Expected output is not shown _______________ Transfer of data Example: - Missing comments discussing the pointers on the receiving end. For example, in fn(), I'd expect the following: void * vp = ctx.suspend(&i); // vp is &x from main()'s call to ctx.resume(&x) int j = *static_cast<int *>(vp); // j == 10 because x == 10 in main() - Expected output is not shown _______________ Exceptions in context-function s/emits/emits/ Is forced_unwind a documented exception type? That is, can it be caught explicitly? If so, the reference to "forced_unwind" should be a link to its documentation and the following might be documented as legitimate: try { // code that might throw } catch (forced_unwind) { throw; } catch (...) { // possibly not rethrow pending exception } _______________ Terminating context Shouldn't this section name be something more like, "Handling execution context termination"? 2nd example: remove the "Done" line. The "never reached" comment can then be applied to "return EXIT_SUCCESS". _______________ Chaining contexts The first two sentences should be merged something like the following: "Boost.Context provides the ability to chain context instances by passing a reference to another context, other than _not-a-context,_ as the last constructor argument." You note that the application terminates or control is transferred back to the last invocation of context::resume(). Might not the transfer also be to context::start() (if suspend()/resume() are never called)? Important: I think you mean, "context::start() must not be called on a context that is a link in the chain begun by another context. That is, call context::start() only on the first context in a chain." _______________ Unwinding stack Name this section "Stack unwinding" 2nd para, 1st bullet: Should "not-a-context" be italicized? Speaking of italics, "context" is sometimes italicized and blue and other times plain. Example: Expected output is not shown Important: s/exception!/exceptions!/ _______________ context.html Variously through this page: s/an context/a context/ or s/an context/an instance/ s/unwinds the stack before destructing it/unwinds the stack first/ s/if precondition is not fulfilled/if a precondition is not satisfied/ s/nxt is linked/nxt becomes a subsequent link in a chain/ s/the execution control/execution control/ s/The execution control/Execution control/ s/Destroyes/Destroys/ Is the move assignment operator safe against self-move assignment? start(): s/with wich/with which/ s/When the function returns/Upon return/ (to avoid confusion about whether start() or fn() has returned) resume(): s/back resuming/back, resuming/ s/ (means suspend()/, which means that suspend() returns/ (note the formatting of "returns" should be normal, not code) "[[Returns:]" is malformed Effects could be rewritten, something like the following, to be clearer: "None, if *this was not suspended by a previous call to suspend(). Otherwise, execution control is transferred back to the caller of suspend(), thereby resuming *this. The argument, vp, will be returned by the previous call to suspend()." suspend(): I think Effects is incomplete. There are spelling errors. How about the following? "Transfers execution control to the caller of the most recent call to start() or resume(). The argument, vp, will be returned by start() or resume()." unwind_stack(): Effects: suggestion: "Destroys all objects allocated on the stack, owned by *this, in the reverse order of their allocation." Non-member function swap(): Effects: suggestion: "As if l.swap(r)." _______________ Stack allocation 1st para: - "stack allocator" should probably be italicized rather than rendered as code. - Concept names are usually rendered with camelcase. Thus, s/stack-allocator/StackAllocator/. 2nd para: This should be the start of a "StackAllocator Concept" section: "StackAllocator Concept "A stack allocator must satisfy the StackAllocator concept requirements shown in the following table, in which a is an object of a StackAllocator type, p is a void *, and s is a std::size_t: " " Expression | Return type | Notes " ----------------------------------------------- " a.allocate(s) | void * | Returns a pointer to s bytes allocated from the stack " ----------------------------------------------- " a.deallocate(p, s) | void | Deallocates s bytes of memory beginning at p, a pointer previously returned by alloc.allocate()" The current documentation of allocate() and deallocate() are no longer needed. Important: This should be rephrased in terms of the concept to something like the following: "The implementation of allocate() might include logic to protect against exceeding the context's available stack size rather than leaving it as undefined behavior." You might add a note that the result of calling deallocate() with a pointer not returned by allocate() results in undefined behavior. _______________ Helper functions 1st para: s/an easy/easy/ _______________ Low level API (boost_fcontext_t) You refer to "ucontext_t" with no link or description. The example code is out of place without first seeing the documentation of boost_fcontext_t and related functions. Following the -> navigation order, the example comes first. Commenting the example and providing an introduction explaining what it illustrates would work. There is no expected output shown for the example. Presumably, the low level API is the part to port to new platforms, yet you don't state that. _______________ Struct boost_fcontext_t and related functions There is no documentation for boost_fcontext_t, particularly as it appears to be just an alias for boost_fcontext. I thought for a moment that you intend to permit different platforms to redefine the typedef to refer to different structures, as needed, but you've documented boost_fcontext_stack's ss_base and ss_limit fields, which suggests that you intend those to be part of the low level, yet documented, API. The result is that I can't figure out the purpose of the typedef. The "fc_" prefix makes sense, since it is used in boost_fcontext. By contrast, the "ss_" prefix does not make sense. I could see "fcs_", for example. ss_limit: Is the stack defined by [ss_base, ss_limit) or [ss_base, ss_limit]? "Pointer to the bottom of the stack" is ambiguous. fc_stack: The description is a little off. How about, "Tracks the memory for the context's stack"? fc_link: The description could be improved: "The address of the next context link in a chain, if any." boost_fcontext_start(): Effects are a little confusing. My suggestion: "Stores the current context data (stack pointer, instruction pointer, and CPU registers) to *ofc and restores the context data from *nfc, which implies jumping to *nfc's execution context. This function must be called when first entering *nfc's execution context." boost_fcontext_start(): Need a "Returns:" "The result of calling boost_fcontext_jump()." boost_fcontext_jump(): This likewise needs some work: Effects: "Stores the current context data (stack pointer, instruction pointer, and CPU registers) to *ofc and restores the context data from *nfc, which implies jumping to *nfc's execution context. The pointer argument, vp, is passed to the current context to be returned by the most recent call to boost_fcontext_start() or boost_fcontext_jump() in the same thread." Returns: "The third pointer argument passed to the most recent call to boost_fcontext_jump(), if any." boost_fcontext_make(): Precondition: s/finished /finishes, / and s/inside/in/ boost_fcontext_make(): Effects: s/if the context is activated next time/when the context is activated next/ _______________ Continuation 1st para: s/from Java/from the Java/ 2nd para: s/for functors objects/for a functor/ 3rd para: You say the co-routines run "in parallel", but there is no parallelism, so you should be clear about what does occur. _______________ ASIO 2nd para: s/a echo/an echo/ 3rd para: I quickly got lost in this description because it assumes familiarity with code presented later. It also assumes familiarity with control flow in Asio which can be described rather than assumed. 3rd para: s/reentered a/reentered, a/ s/a asynch./an async/ 4th para: s/adavantage/advantage/ s/bind()-version/bind() version/ s/easier implemented/more easily implemented/ s/For instance if/For instance, if/ s/a message is partialy received/only part of a message is received/ s/parser or serviced)/parsed or serviced),/ _______________ Performance The bullets are too terse. Perhaps the following captures your intent: "Performance of Boost.Context was measured on the platforms shown in the following table. Performance measurements were taken using rdtsc, with overhead corrections, on x86 platforms. In each case, stack protection was active, cache warm-up was accounted for, and the one running thread was pinned to a single CPU. The code was compiled using the build options, 'variant=release cxxflags=-DBOOST_DISABLE_ASSERTS'. "The numbers in the table are the number of cycles per iteration, based upon an average computed over 1000 iterations." _______________ Rationale NoThrow guarantee: I think you meant the following: "Member functions of context do not throw exceptions but do require that certain preconditions are satisfied: context jumps can only be made by instances which are not a _not-a-context_ and which are not complete." Pimpl idiom, 1st para: s/ it was required to separate both features in separate classes via pimpl idiom/, the use of the Pimpl Idiom was necessary/ Pimpl idiom, 3rd para: I suggest the following: "The Pimpl Idiom allows type-erasing the _stack-allocator_ type." Unwinding: s/resource/resources/ and s/a exception/an exception/ Protecting the stack: There are many changes to make here, so I'll suggest this rewrite: "Because the stack's size is fixed -- there is no support for split stacks -- it is important to protect against exceeding the stack's bounds. Otherwise, in the best case, overrunning the stack's memory will result in a segmentation fault or access violation and, in the worst case, the application's memory will be overwritten. stack_allocator appends a guard page to the stack to help detect overruns. The guard page consumes no physical memory, but generates a segmentation fault or access violation on access to the virtual memory addresses within it." setjmp()/longjmp(): s/The C99/C99/ s/frame, e.g. jumping/frame. Therefore, jumping/ ucontext_t: I don't know why anything in this section is included after the first sentence. ucontext_t, para 1: s/makecontext():/makecontext() is:/ ucontext_t, para 2: s/alter/later/ I would omit the "The signature of func is" part. That's clear from the makecontext() function pointer argument. Windows fibers: s/befor/before/ _____ Rob Stewart robert.stewart(a)sig.com Software Engineer using std::disclaimer; Dev Tools & Components Susquehanna International Group, LLP http://www.sig.com ________________________________ 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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[thread] feature request priority
by Vicente J. Botet Escriba 03 Jan '12

03 Jan '12

Hi, here they are a list of 26 feature requests for Boost.Thread. The features are classified as high, middle and low cost (form my point of view of course) I would like to know which features would you like to find on the next release. Please could you choose 3 features and if possible one for each category, the idea been to provide 1 high, 1 middle and 2 low features for the next release. High #2100 <https://svn.boost.org/trac/boost/ticket/2100> thread fails to compile with -fno-exceptions <https://svn.boost.org/trac/boost/ticket/2100> #6195 <https://svn.boost.org/trac/boost/ticket/6195> Provide the standard time related interface using Boost.Chrono <https://svn.boost.org/trac/boost/ticket/6195> #6217 <https://svn.boost.org/trac/boost/ticket/6217> Make uniform Boost.Thread and Boost.Interprocess synchronization interface <https://svn.boost.org/trac/boost/ticket/6217> #6230 <https://svn.boost.org/trac/boost/ticket/6230> Follows the exception reporting mechanism as defined in the c++11 <https://svn.boost.org/trac/boost/ticket/6230> #5150 <https://svn.boost.org/trac/boost/ticket/5150> boost::thread does not print or return the error value when creating a thread fails. <https://svn.boost.org/trac/boost/ticket/5150> #6194 <https://svn.boost.org/trac/boost/ticket/6194> Adapt to Boost.Move <https://svn.boost.org/trac/boost/ticket/6194> Middle #2741 <https://svn.boost.org/trac/boost/ticket/2741> proposal to manage portable and non portable thread attributes <https://svn.boost.org/trac/boost/ticket/2741> #2880 <https://svn.boost.org/trac/boost/ticket/2880> Request for Thread scheduler support for boost .. <https://svn.boost.org/trac/boost/ticket/2880> #3696 <https://svn.boost.org/trac/boost/ticket/3696> Boost Thread library lacks any way to set priority of threads <https://svn.boost.org/trac/boost/ticket/3696> #4710 <https://svn.boost.org/trac/boost/ticket/4710> Missing async() <https://svn.boost.org/trac/boost/ticket/4710> #4725 <https://svn.boost.org/trac/boost/ticket/4725> Synchronization and shared mutex's Get total_count <https://svn.boost.org/trac/boost/ticket/4725> #5173 <https://svn.boost.org/trac/boost/ticket/5173> boost::this_thread::get_id is very slow <https://svn.boost.org/trac/boost/ticket/5173> #5425 <https://svn.boost.org/trac/boost/ticket/5425> This patch will allow the user to obtain the users thread pointer from a thread group. <https://svn.boost.org/trac/boost/ticket/5425> #5956 <https://svn.boost.org/trac/boost/ticket/5956> Add optional stack_size argument to thread::start_thread() <https://svn.boost.org/trac/boost/ticket/5956> #6227 <https://svn.boost.org/trac/boost/ticket/6227> Use of variadic templates on Generic Locking Algorithms on compilers providing them <https://svn.boost.org/trac/boost/ticket/6227> #6228 <https://svn.boost.org/trac/boost/ticket/6228> Add promise and futures constructor with allocator following the standard c++11 <https://svn.boost.org/trac/boost/ticket/6228> #6229 <https://svn.boost.org/trac/boost/ticket/6229> Rename the unique_future to future following the c++11 <https://svn.boost.org/trac/boost/ticket/6229> Low #1789 <https://svn.boost.org/trac/boost/ticket/1789> thread_group not passing variables <https://svn.boost.org/trac/boost/ticket/1789> #1850 <https://svn.boost.org/trac/boost/ticket/1850> request for unlock_guard (and/or unique_unlock) to compliment lock_guard/unique_lock <https://svn.boost.org/trac/boost/ticket/1850> #2361 <https://svn.boost.org/trac/boost/ticket/2361> thread_specific_ptr: nature of the key, complexity and rationale <https://svn.boost.org/trac/boost/ticket/2361> #2637 <https://svn.boost.org/trac/boost/ticket/2637> shared mutex lock <https://svn.boost.org/trac/boost/ticket/2637> #3567 <https://svn.boost.org/trac/boost/ticket/3567> Request for shared_lock_guard <https://svn.boost.org/trac/boost/ticket/3567> #6224 <https://svn.boost.org/trac/boost/ticket/6224> Add the use of standard noexcept on compilers supporting them <https://svn.boost.org/trac/boost/ticket/6224> #6225 <https://svn.boost.org/trac/boost/ticket/6225> Add the use of standard =delete defaulted operations on compilers supporting them <https://svn.boost.org/trac/boost/ticket/6225> #6226 <https://svn.boost.org/trac/boost/ticket/6226> add explicit bool conversion from locks <https://svn.boost.org/trac/boost/ticket/6226> #6231 <https://svn.boost.org/trac/boost/ticket/6231> Add BasicLockable requirements in the documentation to follow c++11 <https://svn.boost.org/trac/boost/ticket/6231> Patches are welcome for any feature. Note that a feature that have all the needed patches, code, doc and tests could be included soon. Thanks in advance, Vicente

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[thread] Reducing the number of open tickets.
by Vicente J. Botet Escriba 03 Jan '12

03 Jan '12

Hi, I have committed the following tickets in trunk. Fixed Bugs: * [@http://svn.boost.org/trac/boost/ticket/2639 #2639] documentation should be extended(defer_lock, try_to_lock, ...). * [@http://svn.boost.org/trac/boost/ticket/3762 #3762] Thread can't be compiled with winscw (Codewarrior by Nokia). * [@http://svn.boost.org/trac/boost/ticket/3885 #3885] document about mix usage of boost.thread and native thread api. * [@http://svn.boost.org/trac/boost/ticket/3975 #3975] Incorrect precondition for promise::set_wait_callback(). * [@http://svn.boost.org/trac/boost/ticket/4480 #4480] OpenVMS patches for compiler issues workarounds. * [@http://svn.boost.org/trac/boost/ticket/4819 #4819] boost.thread's documentation misprints. * [@http://svn.boost.org/trac/boost/ticket/5423 #5423] thread issues with C++0x. * [@http://svn.boost.org/trac/boost/ticket/5739 #5739] set-but-not-used warnings with gcc-4.6 * [@http://svn.boost.org/trac/boost/ticket/6168 #6168] recursive_mutex is using wrong config symbol (possible typo). * [@http://svn.boost.org/trac/boost/ticket/6200 #6200] patch to have condition_variable and mutex error better handle EINTR. These are tickets with a simple solution or that had associated a complete patch or a clear solution. Anthony I would prefer that you do the merge so that you can check what goes on the release version. I have not closed the tickets. These tickets have just release 1.49 as Milestone. Please, close them when you merge to release. There were 113 tickets two days ago. There are now 114 tickets associated to Boost.Thread. I have closed some duplicates, but some news tickets have been created since. I would like to reduce by 10% the number of tickets every month. I encourage the Boost users that have created tickets for Boost to provide a clear an complete patch when possible so that we can reduce together the number of tickets associated to this Boost library and make it more portable/usable. Don't forget to provide tests that make evident the bug, or to add doc when you are proposing a anew feature. There are a lot of tickets associated to move semantics emulation. I have created a ticket to adapt Boost.Thread to Boost.Move hoping most of these bugs will be solved. As posted in another thread there is already a patch using Boost.Move that could be a good starting point. Of course the help offered by Ion will be too much appreciated. I have created another to adapt the interface to Boost.Chrono, but I will prefer to take care of this once the one for Boost.Move adaptation is committed, as the chance of collisions is big. On the mean time I will continue with some tickets specific to Windows platform. Best, Vicente

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[C++ Now! 2012] Reminder: Call for Submissions, deadline is January 10th, 2012
by Hartmut Kaiser 03 Jan '12

03 Jan '12

INAUGURAL C++ NOW! CONFERENCE 2012 Aspen CO, USA, May 14-18, 2012, www.cppnow.org CALL FOR SUBMISSIONS We invite you to submit session proposals to the Inaugural C++ Now! Conference: C++Now! 2012 (Aspen CO, USA, May 14 - 18, 2012). Based on the successful traditions of 5 years of BoostCon, which was the main face-to-face event for all things C++ and Boost (www.boost.org) C++Now! 2012 will present leading speakers from the whole C++ community. The conference name is changing to C++ Now! to reflect the current value of the language, the focus on its new state (from the new Standard), and the need to continually look to the future so the language remains useful to the C++ community. The focus of this conference will be the new C++11 language Standard and as usual Boost: what's new in C++, its Standard library, and in the Boost libraries, how to write and maintain them, how to evangelize or to deploy Boost within your organization. The new C++ Standard, but also the infrastructure and process of Boost, its vision and mission - no matter what you are interested in, it all comes together in the C++Now! sessions. Meet the colleagues, and feel the inspiration to support your work with C++ and Boost for the next year. The C++ Now! Conference is dedicated to discussion and education about C++, an open and free language and standard. Our Conference will focus on discussion and education about open source software usage and developments in the C++ developer and user community. To reflect the breadth of the C++ and Boost communities, the conference includes sessions aimed at three constituencies: C++ and Boost end-users, hard-core Boost library and tool developers, and researchers pushing the boundaries of computation. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. As a multi-paradigm language, C++ is a melting pot where the most compelling ideas from other programming communities are blended in powerful ways. Historically, some of the most popular sessions at C++Now! have highlighted these concepts, from DSLs to functional programming to transactional memory and more. Bring your C#, Python, Ruby or Haskell influences to bear in an environment that will broaden their exposure. IMPORTANT DATES New proposal submissions due: January 10th, 2012. Proposals decisions sent (tentative program): February 17th, 2012. Fully scheduled program available: February 25th, 2012. Session materials due: April 15th, 2012. BEST PRESENTATION AWARDS We know how much effort it takes to prepare talks for our conference. For this reason we will award the best presentations in the following categories: Best Presentation, Best Short Presentation, Best Tutorial, and Best Workshop. The awards will be given based on the audience's voting. Each award will include the author's name listed on the cover of the C++Now! website for that year and a plaque containing all the C++Now! conference information. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * C++11 and how it changes life for users and library writers * General tutorial sessions on C++11, the C++11 Standardslibrary, and one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to C++11, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 and Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific skills relevant to C++11 and Boost. Workshops Workshops provide an active arena for advancements In Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner These were introduced at BoostCon 2008, and were a great Presentations success They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors We actively encourage tool vendors and ISP's to submit presentations proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL Standard Sessions are 60 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 60 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10- 20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS All submissions should be made through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=cppnow2012. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the C++Now! website and will be available to attendees. For general information on the C++Now! 2012 paper submission or the scope of technical papers solicited, please refer to the conference website at www.cppnow.org. For any other questions about the submission process or paper format, please contact the Program Committee at cppnow2012(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to C++ Now!. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) Dave Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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How to get involved ?
by Vijeenrosh PW Vijeen 03 Jan '12

03 Jan '12

Good Morning , My name is Vijeenrosh P.W . Iam an Computer Science and Engineering student . I have knowledge in c,c++,python and linux , and an mind to extend my areas of knowledge. Recently while passing through the list of GSOC accepted organizations I met with boost libraries . it fits me since I have C++ && programming knowledge and is ready to work . I would like to know how to begin to contribute to the project . Where to begin . or is there any warm up excersices to get passed ? -- Vijeenrosh P.W CSE S3 blog : www.BlackJackVijeen.blogspot.com

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RFC: Multiprecision arithmetic library
by John Maddock 03 Jan '12

03 Jan '12

Folks, I'd like to get some feedback on a multiprecision arithmetic library I've been preparing for possible Boost inclusion. The code is in the sandbox under the "big_number" directory. Docs can be viewed online here: http://svn.boost.org/svn/boost/sandbox/big_number/libs/multiprecision/doc/h… The main features are: * A generic front-end that's capable of wrapping almost any type that's a "number". The front end is expression template enabled and handles all the expression optimization and code reduction. For example it's possible to evaluate a polynomial using Horner's rule without a single temporary variable being created. * A series of backends that need only provide a reduced interface and set of operations, implement the actual arithmetic, currently supported backends are: Integer Types ~~~~~~~~~ 1/ GMP (MPZ). 2/ libtommath. Rational Types ~~~~~~~~~~ 1/ GMP (MPQ). [ But note that the integer types can also be used as template aruments to Boost.Rational ] Floating Point Types ~~~~~~~~~~~~~~ 1/ GMP (MPF) 2/ MPFR 3/ cpp_float - an all C++ Boost-licensed backend based on Christopher Kormanyos' e_float code. [ Note these three types are fully compatible with Boost.Math Trunk - so you get full standard library plus special function support ] There's still a bunch to do, but I'd like to see what folks think, and where the main priorities should be before submission. Thanks in advance, John.

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[test] showtopper for release 1.49 - std::forward not found when compiling with clang 3.0 c++0x mode.
by Vicente J. Botet Escriba 03 Jan '12

03 Jan '12

Hi, I have created a show stopper ticket https://svn.boost.org/trac/boost/ticket/6345 as after updating the trunk, I'm unable to test any library using Boost.Test. Recent modification on Boost.Test make it unusable with clang 3.0 c++0x due to std::forward missing or not found. clang-darwin.compile.c++ ../../../bin.v2/libs/thread/test/test_thread.test/clang-darwin-3.0x/debug/threading-multi/test_thread.o In file included from test_thread.cpp:16: In file included from ../../../boost/test/unit_test.hpp:19: In file included from ../../../boost/test/test_tools.hpp:328: In file included from ../../../boost/test/tools/impl.hpp:25: ../../../boost/test/tools/assertion.hpp:278:21: error: no member named 'forward' in namespace 'std' : m_value( std::forward<T>(val) ) ~~~~~^ ../../../boost/test/tools/assertion.hpp:278:29: error: 'T' does not refer to a value : m_value( std::forward<T>(val) ) ^ The revision is https://svn.boost.org/trac/boost/changeset/75370 #ifndef BOOST_NO_RVALUE_REFERENCES explicit value_expr( T&& val ) : m_value( std::forward<T>(val) ) #else explicit value_expr( T const& val ) : m_value( val ) #endif #ifndef BOOST_NO_RVALUE_REFERENCES operator->*( T&& v ) const { return value_expr<T>( std::forward<T>( v ) ); } #else operator->*( T const& v ) const { return value_expr<T>( v ); } #endif This has as consequence that the authors developing mainly with this compiler and using Boost.Test to be unable to deliver new modifications. I have added #include <utility> without success. I guess that the standard library doesn't provides this function even if the compiler provides rvalue references. The code should test for a macro that states if std::forward is available. Please could someone help on this issue? Best, Vicente

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