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[lclcontext] Any interest in Pythonesque "with-as" statement in C++.
by Mostafa 18 Aug '15

18 Aug '15

I think Python's concept of Context and Context Managers useful and I've adapted, to the best of my abilities, a similar concept in C++. For those not familiar with this concept, I'll quote a brief snippet from the documentation: "Simply stated, this library enables the use of the Pythonesque with-statement construct in C++. More broadly, this library seeks to formalize a generalized version of a subset of the RAII (Resource Acquisition is Initialization) idiom that, for the lack of preexisting terms, I shall refer here to as the STEP (Scope Triggered Event Processing) idiom. The STEP idiom is the commonly occurring use case where for a given block of code some user specified action(s) must execute on entry and on exit, and the failure to do so will result in some deterministic behavior." You can find the library here: https://github.com/m-w-a/WG Documentation is here: https://github.com/m-w-a/WG/tree/master/Local/Docs (In the same repository I've also redid Boost's local_function, but that the subject of another posting.) If there is enough interest from the community for such a library then I will go ahead and "Boostify" it.

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[http] Formal Review
by David Sankel 16 Aug '15

16 Aug '15

> 1. Should Boost.Http be accepted into Boost? Please state all conditions for acceptance explicity. No. This library unfortunately is not complete enough to be in Boost. > 2. What is your evaluation of the design? >From my reading, the design of the low level components that are in the library seems okay. > 3. What is your evaluation of the implementation? Looks okay from what I've seen. > 4. What is your evaluation of the documentation? More tutorials for common use cases are needed. I fear, though, that the only use case of these low-level components is the writing of a higher-level one on top of it that is more widely useful. > 5. What is your evaluation of the potential usefulness of the library? In its current state, I do not find this library very useful. A Boost HTTP library should support both client side and server side. Micro-services are quite commonly used these days and only communicating one direction excludes this library from having full participation. While I very much enjoy and appreciate the exposed lower-level functionality, higher level abstractions are required to scratch the itch most developers have when they want a C++ HTTP library. I could not recommend this library over pion for this reason even though I like this library's design better. In particular, we need really good stories for: a) How to fetch the contents of a website given a URL. b) How to make a static page server. c) How to write code that handles a POST or GET request dynamically based on specified parameters. d) How to write a server that accepts file uploads. e) HTTP/2.0 f) Websockets I would also like to see instances of this library being used in production. That would give some evidence that the design works in practice. There is the argument that we should accept this into Boost now because, once it has more features, it'll be really great. I think that Boost is for libraries that are already really great. I don't see how getting more exposure to an incomplete library helps either Boost or the library, but I do see how it can do damage to the Boost name. > 6. Did you try to use the library? With what compiler? Did you have any problems? I built the library and ran the single example. I used gcc 5.2.0. I didn't run into any problems and was quite happy with this part of the review. > 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? I spent a couple hours reading through the documentation and the mailing list discussions. > 8. Are you knowledgeable about the problem domain? Yes. I'm the architect of a large C++-based web framework for the US Government. We currently use pion as our primary server and client low-level library. I've contributed some minor patches to pion. -- David Sankel

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[lclfunction][local_function] Any interest in a redone version of local_function.
by Mostafa 16 Aug '15

16 Aug '15

I've made a library called lclfunction which is basically a redone version of local_function except for the following important differences: 1. This library allows the function name to be specified at and only at the top of the local function declaration. 2. This library allows local functions to maintain internal state without referencing external variables (via varset). 3. This library allows the use of globally scoped types as macro parameters, i.e., ::std::pair<..., ...>. 4. This library can handle binding array types. 5. IMHO, this library has a cleaner implementation: a) The preprocessor translator is partitioned into a front end and back end. b) A well-defined symbol table bridges the two translation layers. c) It has well-defined error-generating mechanism with a separate error pass before code generation. 6. It uses a different syntax. The main reason I did this redone library is because local_function required putting the function's name in the closing macro and that rubbed me the wrong way, my view is that it should and can be placed in the opening macro. If there is enough interest from the community I will "Boostify" it. Thanks, Mostafa

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boost.org https certificate expired 4 month ago
by Jens Weller 16 Aug '15

16 Aug '15

Hello boost community, I noticed today that the https of boost.org is expired, and should have a new certificate: https://www.ssllabs.com/ssltest/analyze.html?d=boost.org thanks, Jens Weller

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[http] Formal Review
by Antony Polukhin 16 Aug '15

16 Aug '15

Hi, This is my formal review for Boost.HTTP library. 1. Should Boost.Http be accepted into Boost? No. It has some big architectural issues and a lot of issues in code. 2. What is your evaluation of the design? That's the fatal problem of the library. It seems like the library attempts to get best from ASIO and cpp-netlib and unfortunately fails. Now let's get into details: * ASIO is a low level abstraction over protocol that does not take care about memory management of buffers (in most cases it's the responsibility of user to allocate and keep alive the required buffers). * cpp-netlib takes care of memory management, hides low-level stuff. Boost.Http is stuck somewhere in the middle: sometimes it allocates and extends buffers, sometimes not. Because of that the design does not seem solid. Any attempt to hide all the memory management inside the library will end in an another implementation of cpp-netlib. So it seems right to remove all the memory management from the library internals and make the library closer to ASIO. Here are my recommendations for separation of flies and dishes: * Stick to the idea that http socket must ONLY manage connection without extending the ASIO's send/receive function signatures. That means that http1.0 and http1.1 sockets must be almost a typedef for tcp/ssl socket. Http2.0 socket must be very close to SSL socket. No additional methods (like async_read_trailers or async_write_response) must be provided. * It must be a user's responsibility to provide buffers for messages. Never extend buffers in socket-related methods. * Provide helper classes that parse and generate http * Provide out-of-the-box completion conditions for async_read operation: http::completions::full, http::completions::headers, http::completions::body... Those bullets will allow to write following code (based on http://www.boost.org/doc/libs/1_58_0/doc/html/boost_asio/tutorial/tutdaytim… with minimal modifications): #include <ctime> #include <iostream> #include <string> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/asio.hpp> std::string make_daytime_string() { using namespace std; // For time_t, time and ctime; time_t now = time(0); return ctime(&now); } class http_connection : public boost::enable_shared_from_this<http_connection> { public: typedef boost::shared_ptr<http_connection> pointer; static pointer create(boost::asio::io_service& io_service) { return pointer(new http_connection(io_service)); } http::socket& socket() { return socket_; } void start() { message_.resize(4 * 1024); boost::asio::async_read(socket_, boost::asio::buffer(message_), http::completions::full(message_), // read until all the whole request is in `message_` boost::bind(&http_connection::handle_read, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } private: http_connection(boost::asio::io_service& io_service) : socket_(io_service) {} void handle_write(const boost::system::error_code& /*error*/, size_t /*bytes_transferred*/) {} void handle_read(const boost::system::error_code& error, size_t bytes_transferred) { assert(!error); // for shortness // `message_` contains the whole request, including headers and body // because http::completions::full was provided { boost::system::error_code e; http::view v(message_, e); // represent buffer as http message assert(!e); // no error occured during parsing assert(v.read_state() == http::read_state::empty); std::cerr << v.version(); // "HTTP1.1" std::cerr << v["Content-type"]; // "plain/text" std::cerr << v.body(); // string_ref("Hello! This is a body content. What time is it?") message_.clear(); // `v` is now invalid to use! } { http::generator resp(message_); // use `message_` for an output resp << make_daytime_string(); // append daytime to body resp["Content-Type"] = "plain/text"; // set some headers resp.version(http::version::HTTP_1_1); // explicitly set HTTP version resp.code(200); // "200 OK" resp.flush(); // explicitly flush to buffer. Done automatically in destructor } boost::asio::async_write(socket_, boost::asio::buffer(message_), boost::bind(&http_connection::handle_write, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } http::socket socket_; // manages the connection only std::string message_; }; class http_server { public: http_server(boost::asio::io_service& io_service) : acceptor_(io_service, http::endpoint(http::all_versions, tcp::v4(), 80)) { start_accept(); } private: void start_accept() { http_connection::pointer new_connection = http_connection::create(acceptor_.get_io_service()); acceptor_.async_accept(new_connection->socket(), boost::bind(&http_server::handle_accept, this, new_connection, boost::asio::placeholders::error)); } void handle_accept(http_connection::pointer new_connection, const boost::system::error_code& error) { if (!error) { if (new_connection->socket().version() == http::version::HTTP_2_0) { // do some more stuff } new_connection->start(); } start_accept(); } http::acceptor acceptor_; }; int main() { try { boost::asio::io_service io_service; http_server server(io_service); io_service.run(); } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; } This will also untie Boost.HTTP from ASIO. Now users could use http::generator/http::view to read/generate HTTP data. This significantly extends the use cases of your library (for example on a previous work we had our own network transfer implementation, but we'd gladly use a http parser and generator). Such code is also less intrusive: only minimal chages were required to change a tcp example into the http example. Users will appreciate that, especially in cases when ASIO is already used for HTTP. BTW, after that you could easily implement http::stream (that must be close to tcp::stream by functionality). http::stream would be a killer feature that would be widely used by utility programs (as I remember current Boost's regression testing requires it, but uses tcp::stream with a bunch of workarounds). Please, implement the HTTP2.0 protocol. There are some open source solutions that are licensed under the Boost license and are very close to full implementation of HTTP2.0. Just reuse the code and chat with the authors for better understanding of the problems. 3. What is your evaluation of the implementation? Not perfect. For example https://github.com/BoostGSoC14/boost.http/blob/master/include/boost/http/so… It seems that `std::vector<asio::const_buffer> buffers; buffers.reserve(nbuffer_pieces);` is meant to be here. There are more such places... It seems that some useful features (like custom allocators) are not supported by the library. It's better to be fixed. Some of the implementation issues are because of the library design. For example requesting multiple async operations (async_read_request+async_read_some+async_read_trailers) is performance hit. It's better to read all the data at once (just like in the example from above). 4. What is your evaluation of the documentation? First code snippet in tutorial contains mostly ASIO's stuff and almost no HTTP stuff. That's wired... If bullets from above would be implemented, then I'd rather start with parsing and generating simple http messages. Then an example with sockets could be provided. Also please do not use coroutines at least in first example. coroutines is a new feature in ASIO, many users use old Boost versions that have no coroutines and some users are not familiar with them. So if you start with coroutines user will have to go to ASIO docs and dig into coroutines to understand the very first example. Example without coroutines will be more user friendly. 5. What is your evaluation of the potential usefulness of the library? Library is very useful and required. But in current state it must not be accepted into Boost. 6. Did you try to use the library? With what compiler? Did you have any problems? Have not tryed. 7. How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? A few hours digging into docs, about 3 hours looking into the sources, about 3 hours formulising the issues and recommending solutions. 8. Are you knowledgeable about the problem domain? Not an expert, but used ASIO a lot along with cpp-netlib and some other libraries close to the proposed one. 8.3333(3) Review Please, reserve a bigger window when such complex library is proposed for review. It's hard to review it in 10 days. 8.6666(6) For Reviewers I urge other reviewers to take a look at the cpp-netlib. If you treat Boost.Http as an out-of-box solution, then cpp-netlib is more mature, user-friendly and solid. If you treat Boost.Http as a basic building block for HTTP (just like ASIO is a basic building block for networking), then it's better to stick to the ASIO's design and do not *partially* manage memory! P.S.: I hope that this library would be changed according to my recommendations and submitted for a new review. -- Best regards, Antony Polukhin

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Niall Douglas 15 Aug '15

15 Aug '15

On 7 Aug 2015 at 19:29, Vinícius dos Santos Oliveira wrote: > > I do not believe Http is ready for peer review for these reasons, and > > I personally would urge you withdraw it until you have fixed these > > issues and then come back to us. If you do not withdraw it, I will > > vote for rejection. > > Can I persuade you to review the Boost.Http design? I'd reject myself if > you find any fundamental flaw on the design and even if you're going to > reject the library because the lack of tooling (not directly related to > design or documentation, which are the most important items on any > library), it'd be useful to know what needs to be addressed on the design > before I submit again (in the case the submission is rejected). I think my earlier email was poorly phrased now I've slept on it. I made my objections seem like they were about portability, when they were really about design and intent of Http. What I should have said was this: Standalone ASIO is the reference Networking TS implementation for standardisation. Http is currently a set of extensions to Boost.ASIO specifically when it *should* be a set of extensions to the reference Networking TS implementation for C++ standardisation. This is why your current design and architecture is flawed, but luckily there isn't too much work to fix this by finishing the port of Http to the Networking TS. The Internet of Things tends to involve lots of small somewhat underpowered internet devices where C++ is likely going to play a much more important role than historically in embedded systems. The chances are that any Networking TS in C++ will be very extensively used in such IoT applications. If there were also a high quality set of extensions adding HTTP support to the Networking TS, I think your chances are good that your Http library would be seriously considered by WG21 for standardisation. *This* is why I very strongly believe that Http needs to cleave itself tightly to the Networking TS reference implementation, and not to Boost.ASIO. Moreover, if you make Http an extension of the Networking TS, you get Boost support with that for free - Http becomes dual use. > About C++03 support, it's not required for Boost acceptance, so I can add > later. I want to increase tests coverage a lot before porting code to > C++03, so I don't introduce accidental bugs in the process. As a strong advocate for C++ 11 over 03 I can understand. However, IoT developers tend to be stuck on some pretty ancient toolsets for longer than others. 03 support I think would greatly increase your potential userbase. > In the case the abstractions I need enter on the C++ standard, maybe your > APIbind will help me. I actually would advise you to choose ASIO's STL abstraction machinery over my own alternative APIBind in this instance. > But I just don't find any reference to BOOST_ASIO_HAS_STD_SYSTEM_ERROR > outside of config.hpp. Even if it was used, it is undocumented, which means > it is an implementation detail that won't be guaranteed to be there forever > (accidental behaviour versus a documented guarantee). I'm pretty sure that implementation detail won't change in a hurry. STL abstraction machinery changes as quickly as a STL does i.e. every decade or so. > > https://svn.boost.org/trac/boost/wiki/BestPracticeHandbook#a7.SAFETY:S > > tronglyconsideranightlyorweeklyinputfuzzautomatedtestifyourlibraryisab > > letoacceptuntrustedinput > > That's why this first implementation uses a proven-parser that is very well > tested. The buck always stops with the top most layer, not internally used third party libraries. You NEED to fuzz test untrusted inputs when parsing HTTP. For all you know, your STL implementation could be the thing with the overflow bug, or the way in which you use it. > > * I don't understand why you cannot issue more than one async read at > > a time nor async write at a time. In something like pipelined HTTP > > that seems like a very common pattern. I smell a potential design > > flaw, and while the docs mention a "queue_socket" I can't see such a > > thing in the reference section. > > > > Too much synchronization and buffering. > > The pipeline has the following requests: > > A => B => C > > If I were to allow replies to request B, the design would be more complex, > increasing the difficult to implement alternative backends and everyone's > life. Also, the reply to request B cannot actually be sent while the reply > to request A is on hold. This means that the whole response to request B > would need buffering and if response B is a video live stream, this means > an implicit (the user cannot know) crash after an unfortunate memory > exhaustion. I couldn't claim a **lightweight** server if this excessive > buffering was to occur. I couldn't claim the project is appropriate for > embedded devices if I had chosen the buffering approach. It's a trade-off. > I should write about it in the "design choice" of the documentation. > > HTTP/2.0 does have proper multiplexing and it can be more useful to respond > several requests without "head of line blocking". Ok, let's accept that HTTP before 2.0 can't multiplex (not my experience personally, but I agree it's got big gotchas before 2.0). You need a user facing API for Http which lets user code multiplex where that is available, and not multiplex when that is not available. In other words, identical code written against Http must automatically be optimal in either connection case. You're probably going to ask how I might implement that right? I think my first guess is you need two completion handler layers and therefore two completion dispatcher reactors: the bottom layer is the same as ASIO's and uses the ASIO reactor, whilst the top layer which users of Http sees is a reactor operated by Http and is disconnected, though operated by, the ASIO reactor. > A queue socket is a concept, I don't provide one. I can look into how make > the documentation less confusing by adding a page exclusively dedicated to > explain the problem it solves. Would that work for you? It could be this queue socket concept of yours is exactly what I just proposed as two completion handler and reactor layers. In either case, I don't think queue sockets should be a concept, I think they need to be the core of your library's user facing API. If power users wish to bypass that user facing API layer for less hand holding and less latency, that should also be possible. But I think HTTP multiplexing should be assumed to be the default starting point for Http applications. Once HTTP 2.0 is more common, it will seem madness that Http's user facing API is _not_ 100% multiplexing. > * Your tutorial examples use "using namespace std;" at global level. > > That's a showstopper of bad practice, and you need to purge all of > > those. Same for "using namespace boost;" at global level. > > > > The tutorials should be as small as possible to not scary the users. > > But I can put a comment "you should avoid using namespace". Does it help? using namespace is fine at local scope. It's not fine at global scope. Replacing all global using namespace with local using namespace is all you need to do. > * Your reference section is one very long thin list. You might want > > to use more horizontal space. > > > > I'd be happy already if I knew hot to remove the TOC from the reference > page. It'd be much more clean already. Personally in AFIO I hack the CSS to make the list into columns. ASIO employs a table. There are many solutions. > * I personally found the design rationale not useful. I specifically > > want to know: > > > > 1. Why did Http choose ASIO as my base over leading competitor X > > and Y? > > 2. What sacrifices occurred due to that choice? i.e. things I'd > > love weren't the case. > > > > I assume I don't need to reply these questions during the review, given the > reviewers may already be experienced on the answers. Well ... I'm not sure that's actually the case. It's not we don't have opinions on the answers, it's whether our answers are different to your answers. You'll see this during the AFIO review later this month - I have some really weird opinions no one else shares like choosing my own custom lightweight monadic future-promise implementation over async_result. That will be the source of much criticism I'm sure. > 3. What alternatives may be better suited for the user examining > > Http for suitability and why? i.e. make your documentation useful to > > people with a problem to solve, not just a howto manual. > > > > I don't quite understand this point. What I'm really asking is for details of when before starting Http you reviewed the options available and the designs they used, and exactly why you chose the design choices in Http you did with reference and comparision to prior art. Like a literature review, but for programming libraries. Does this make sense? It's partially for us to help us understand your choices, but also to help those examining Http to see if it's useful to them to figure out the best solution to their problem (which may be to use an alternative to Http). Documentation which is useful over documentation which is reference. > * Benchmarks, especially latency ones which are important for many > > uses of HTTP are missing. I'd particularly like to know confidence > > intervals on the statistical distribution so I know worst case > > outcomes. > > > > These values will change when I replace the parser used now. Also, they can > change based on the buffer sizes and parser options, which the user is/will > be able to change. > > Nevertheless, I do want to do some serious benchmarking, specially because > it'll give me a reference point when I write my own parser and want to > compare performance speedup. I can do some poor benchmark this weekend and > show the results. That would be interesting, but don't go crazy on it. Also, please do enable the undefined behaviour sanitiser permanently including in release mode and with full stack smashing protection before running benchmarks. Anything parsing malicious input should have all those turned on where available. > I hope all the above isn't too disheartening Vinícius. > > Not at all. I think you're the second person to dedicate more time > reviewing my work and this isn't disheartening at all. Just that your > feedback is usually around tooling and not the design itself (everybody has > its preferences). That's because I like the design a lot and have little bad to say about it. I've also been subscribed to your github since the beginning, and I have been reviewing your code on and off as you wrote it. You're a talented programmer. > > Jamfile for the main library build, > > Consider this done. I won't integrate into Boost without removing CMake > first. This was already partially stated in the Bjorn's announcement (but > somehow implicit, to be fair). I have no problem at all with dual build systems if you're happy keeping both maintained. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Re: [boost] [asio-users] [http] Formal review of Boost.Http
by Niall Douglas 15 Aug '15

15 Aug '15

On 13 Aug 2015 at 8:58, Vinícius dos Santos Oliveira wrote: > First of all, sorry to all members of the list about my unavailability. I > was planing to write an experimental HTTP 2.0 backend, so I could give more > confidence about how much I believe this Boost.Http core I present for > review is the right abstraction. > > Anyway, looks like I took the wrong approach. I should have answered the > easiest questions first and implement the HTTP 2.0 backend (experimental, > using existing-library and not Boost-quality) later. That's a wise move Vinícius I think. > > Where I'm really at is I think if Http is accepted you're going to > > either have to ditch it and reimplement atop the Networking TS as > > Chris folds the substantial changes WG21 will force onto ASIO into > > Boost.ASIO, or end up refactoring Http to cleave more closely to the > > Networking TS anyway. > > I'm okay with that. You may be, but I would worry about your users. Boost users expect stability and permanence. > > I think for the majority of HTTP users they just want it to work > > without surprises to a high default performance level. If you look at > > the history of the HTTP library support in Python you'll see what I > > mean - firstly, it's surprisingly easy to get a HTTP library API > > design wrong, even in a v2 refactor. And secondly that people need > > both a stupid-simple API and a more bare metal API *simultaneously* > > with HTTP, and therein lies the design gotcha. > > > > If you want a high level API, you're going to use coroutines. There is > nothing in the wild so readable as coroutines. Coroutines are **the** > solution to solve spaghetti code in asynchronous abstractions. Lambdas and > futures will never be as readable as coroutines. Anyway... God no. I would see a top level API as being synchronous, so something like python's urllib3: import requests r = requests.get('http://www.boost.org') print(r.json()) It may coroutinise but still appear to be synchronous, but that's a separate moving ball and not one Http can tackle alone. > The more I think, the more I believe how much such "middle-level" API is > underestimated. > [snip] > It's not really like Boost.Http is too low level. It's more like only the > less polemic building blocks are available now. You'll see the same main > players in a higher-level abstraction and the main difference is most > likely that you won't manage the main players yourself. Think of it as a Boost user. The average Boost user is going to see Boost.Http and think to themselves, "oh goody I can now write: import requests r = requests.get('http://www.boost.org') print(r.json()) ... in C++ and yay I've just chopped 10,000 lines of buggy hack code from my codebase." And that's exactly what I would expect too from a library called Boost.Http. What you're providing isn't that though: it's a set of low level HTTP related extensions to Boost.ASIO. From my review of your code and docs, and what you've told me, I think the ideal location for your library is within ASIO under the asio::http namespace. However, assuming Chris isn't keen to allow that as a git submodule within ASIO (he might be, I don't know), I think as a very minimum you need a name for your library which says it is a set of low level HTTP related primitives for Boost.ASIO. That name is not Boost.Http for sure. A later library you might submit could be called Boost.Http, but it would provide a daft easy API like the above for Python's urllib3. In fact, if you can achieve a more appropriate name choice, I'll change my vote from rejection to a conditional acceptance as you've done a great job in persuading me from where I was. You've impressed with me your awareness of the tradeoffs involved in a moving API environment, and though I severely personally disagree with your choice of Boost.ASIO over ASIO, I can also see that targeting a more stable API in the form of Boost.ASIO for now makes sense. How does that sound? Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Making the Windows binaries 'official'
by Tom Kent 15 Aug '15

15 Aug '15

<history> After the boostpro.com organization dissolved, there was never an official place to go to get pre-built binaries for the releases. Some random components were made available on the sourceforge download page and I had been hosting them on my own website (http://boost.teeks99.com) since I started building them around the release of 1.37. A couple years ago, before the release of 1.54, I asked the community if they would like my builds to be hosted on the sourceforge site, and the answer was positive: http://lists.boost.org/Archives/boost/2013/04/202460.php Since the 1.54 release, I've generally been uploading the windows binaries based on the RCs and enabling the downloads just a few minutes after the release notice goes out. </history> I would now like to propose that we make these libraries an official part of each Boost release. I don't think this entails much, just the following: 1) Have the release team coordinate with me to ensure that the binaries are ready before announcing the release. 2) Include a link to them in the release announcement. 3) Link to them from the website. It would also be good to get others who can run the scripts to perform the build, if I am someday unable to do this. The biggest hurdle here is having a (virtual) machine with all six versions of visual studio on it. Is this something the community would be in favor of? I know that many of the people on these lists don't use windows and if they do are generally capable of building the windows binaries themselves, however there is a large group out there that prefers to just get the installer for them (like they do for other projects like Qt, wxWidgets, etc). Thoughts? Tom Kent

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[job] exec job-graphs in a NUMA env (was a thread pool that allows recursive calls)
by Oliver Kowalke 15 Aug '15

15 Aug '15

This library is related to the posting 'a thread pool that allows recursive calls' (http://lists.boost.org/Archives/boost/2015/06/223426.php) e.g. the library solves the many-dependent-jobs problem. boost.job is a derivative work of boost.task (which was published in 2008, the code is refactored and now split into boost.context, boost.coroutine2/boost.fiber and boost.job). boost.job provides a framework for asynchronous execution of job-graphs (a job is a small unit of code that can be executed independently and parallel, e.g. it's a fain-grained work item) of arbitrary dependency, e.g. solving the many-dependent-jobs problem (M: worker threads, N: jobs waiting for other jobs; M << N). Each (logical) processor of a dedicated processor set (configurable) gets a worker-thread assigned. Each worker-thread runs a fiber-pool (launch policy is customizable). A submitted job is always executed by a worker-fiber. While using boost.fiber jobs are scheduled cooperatively so that a job can yield to other jobs during its execution. Jobs can be synchronized via primitives like mutex's, conditions, barriers and channels (message exchange) from boost.fiber without blocking the worker-thread. Fibers provide a fast context switch. boost.job supports to inspect the NUMA topology (e.g. which logical processors are online, and which processors share L1/L2/L3 cache). This information can be used to select a appropriate processor for a job. For a fast access to job related data, boost.job provides functions and classes to allocate memory on NUMA nodes (processors of a NUMA node share cache and have a faster access to its associated memory bank than processors of other nodes.). source: https://github.com/olk/boost-job documentation: http://olk.github.io/libs/job/doc/html/

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Re: [boost] Build Error VS14 + Intel 15.0 (Update 4, the latest)
by degski 15 Aug '15

15 Aug '15

Changing intel-win.jam, line 476 (boost 1.59.0 rc2) from: .iclvars-15.0-supported-vcs = "12.0 11.0 10.0 9.0" ; to: .iclvars-15.0-supported-vcs = "14.0 12.0 11.0 10.0 9.0" ; solves the problem.

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