January 2024 - Boost-users - lists.preview.boost.org

Fwd: Using ASIO to wait on a foreign socket being readable, with a timeout
by Dominique Devienne 19 Jan '24

19 Jan '24

Sorry, sent originally to the wrong list. And this is on Windows 10 too, BTW. Haven't tried Linux with that code yet. --DD ---------- Forwarded message --------- From: Dominique Devienne <ddevienne(a)gmail.com> Date: Thu, Jan 18, 2024 at 7:18 PM Subject: Using ASIO to wait on a foreign socket being readable, with a timeout To: <boost(a)lists.boost.org> Hi, I'm trying to use ASIO to wait until a socket is ready to read, or timeout. This is a blocking wait. But the socket is not "owned" by ASIO, but is from the libpq PostgreSQL connection. So ASIO should NOT consume any of the input on the socket, just notify me when that socket is "read-ready". I've cobbled together the following test code: ``` const int socket2 = PQsocket(conn2.handle()); BOOST_CHECK(socket2 > 0); int timr_err_code = 0; int sock_err_code = 0; bool timr_aborted = false; bool sock_aborted = false; std::string timr_err_msg; std::string sock_err_msg; bool timed_out = true; auto c1 = "C# 1"sv; conn2.listen(c1); conn1->notify(c1, "wake up!"sv); { boost::asio::io_context io_ctx; boost::asio::ip::tcp::socket io_sock(io_ctx); io_sock.assign(boost::asio::ip::tcp::v4(), socket2); boost::asio::steady_timer io_timer(io_ctx); io_timer.expires_from_now(std::chrono::milliseconds(100)); io_sock.async_wait( io_sock.wait_read, [&](const boost::system::error_code& errc) { if (errc) { sock_err_code = errc.value(); sock_err_msg = errc.message(); sock_aborted = (errc == boost::asio::error::operation_aborted); } timed_out = false; //io_timer.cancel(); io_ctx.stop(); } ); io_timer.async_wait( [&](const boost::system::error_code& errc) { if (errc) { timr_err_code = errc.value(); timr_err_msg = errc.message(); timr_aborted = (errc == boost::asio::error::operation_aborted); } io_sock.cancel(); io_ctx.stop(); } ); io_ctx.run(); // blocks until either async op above runs } // there's a notif to read, so io_sock.async_wait should have completed BOOST_CHECK_EQUAL(timr_err_code, 0); BOOST_CHECK_EQUAL(sock_err_code, 0); BOOST_CHECK_EQUAL(timr_err_msg, ""); BOOST_CHECK_EQUAL(sock_err_msg, ""); BOOST_CHECK_EQUAL(timr_aborted, false); BOOST_CHECK_EQUAL(sock_aborted, false); BOOST_CHECK_EQUAL(timed_out, false); auto notif = conn2.notification(); BOOST_REQUIRE(notif); BOOST_CHECK_EQUAL(notif.backend_pid(), pid1); BOOST_CHECK_EQUAL(notif.channel(), c1); BOOST_CHECK_EQUAL(notif.payload(), "wake up!"sv); ``` The io_sock.async_wait(io_sock.wait_read, ...) succeeds, the IO loop stops as expected, but when I try to PQconsumeInput() from the LIBPQ connection next (as shown in the code below) ``` Notification Connection::notification() { auto [lock, hndl] = ensure_handle(); if (1 != PQconsumeInput(hndl)) { throw std::runtime_error(error_msg()); // <<<<<< THROWS } PGnotify_uptr notif{ PQnotifies(hndl) }; return Notification(std::move(notif)); // may be null } ``` that calls fail with this error message: fatal error: in "NotificationTests/test_across_backends": class std::runtime_error: could not receive data from server: Socket operation on non-socket (0x00002736/10038) LIBPQ didn't like what ASIO somehow did on the socket descriptor. The LIBPQ doc says to select() the descriptor, but I thought ASIO would be cleaner, more C++, and perhaps more cross-platform. Can somehow help, telling me if I'm using ASIO incorrectly here? Thanks, --DD

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[Scope] Peer review conclusion
by Дмитрий Архипов 15 Jan '24

15 Jan '24

Dear Boost community, the formal review of Boost.Scope has taken place between 26th of November and 5th of December of the previous year. I have received 5 reviews in total, including 4 here on the mailing list and 1 on Reddit. Two of the reviews recommended unconditional, and 3 conditional acceptance. The reviews came from: - Klemens Morgenstern, - Janko Dedic, - Julien Blanc, - David Sankel, - /u/jonesmz on Reddit. Also, several people have given insightful comments but did not provide a review. I would like to thank all of the people who took their time to write reviews or participate in the discussions. Your effort was very important and valuable. The outcome of the review is that Boost.Scope is ACCEPTED with several minor CONDITIONS. 1. noexcept specification on destructors of scope guards should be properly documented. Andrey has already commented that the technical hurdle that prevented it was eliminated. 2. There should be a good motivating example for scope_success. There was a lot of comments regarding scope_success and its seeming uselessness. Without a good example I see the same pattern occurring with future users. 3. The examples should better describe what they are trying to achieve. Several comments about examples suggested incorrect changes, which signals that readers failed to understand them. After a lot of consideration I decided against requesting the author to remove unique_resource and related functionality from the library. While several reviewers wanted a more "concise" library, all noted that the component is useful. One last thing I wanted to point out is that all reviewers and most commenters were adamant that compatibility with the Technical Specification on which this library was initially based should not be a goal. In fact, Andrzej Krzemienski even noted that such compatibility has prevented him from adequately evaluating the library on its own merit. In my opinion this should be a sign to all of us that people prefer better APIs over standard APIs. I recommend Andrey to re-evaluate those parts of the library's APIs that he copied from the TS and potentially pick better names for member functions. Thanks to Andrey for submitting this library to Boost. And thanks again to the reviewers and everyone who provided feedback, who ultimately made this review possible.

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Using Boost in CLR Class
by 임성준 09 Jan '24

09 Jan '24

Hello, I have question about using Boost. I'm trying to using boost in clr class of Visual Studito 2022 When I build the project, I got following error Error C1189 #error: "This library now requires a C++11 or later compiler - this message was generated as a result of BOOST_NO_CXX11_REF_QUALIFIERS being set" ClassLibrary2 C:\Users\bussly\source\repos\ClassLibrary2\packages\boost.1.84.0\lib\native\include\boost\multiprecision\detail\check_cpp11_config.hpp 34 Error (active) E0035 #error directive: "This library now requires a C++11 or later compiler - this message was generated as a result of BOOST_NO_CXX11_REF_QUALIFIERS being set" ClassLibrary2 C:\Users\bussly\source\repos\ClassLibrary2\packages\boost.1.84.0\lib\native\include\boost\multiprecision\detail\check_cpp11_config.hpp 58 Even I didn't make any code, just add an include boost header. Following is the scenario of what I did - Visual Studio 2022 - Create new project -> CLR Class Library(.Net Framework) - Install NuGet Package -> boost 1.84.0 - Add include boost -> #include "boost/geometry.hpp" - Build solution - Error and following is properties of my project - Platform Toolset: Visual Studio 2022(v143) - C++ Language Standard: ISO C++ 20 Standard(/std:c++20) - C Language Standard: Default(Legacy MSVC) I tried with C++ 14 and C++ 17 also, but failed. Can I get any solution for this? Thank you.

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[Boost.Redis] Single Connection Concurrency Inquiry
by Samarah Uriarte 08 Jan '24

08 Jan '24

Hello, I am using the Boost Redis library to write to a local Redis server and would like to inquire about how a single connection can handle concurrent calls. I have several C++ classes that have their own Boost.Redis connections, but this is leading to ASIO-related hanging behavior that is difficult to debug. I would like to simplify the design by initializing only one connection that can be used by all of these classes instead. I know the "async_exec" method supports concurrency but I wonder if this might cause any future issues with larger workloads. Thank you in advance. Sincerely, Samarah Uriarte

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Problems downloading boost on Linux
by Gonzalo Garramuño 01 Jan '24

01 Jan '24

I have tried downloading boost 1.76 on Linux from Argentina with: curl -# -L -o boost_1_76_0.zip.tmp https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/boost_1_76… and also from the boost web page. This leads to a redirect to JFrog. I tried creating an account with both Google (which led to Invalid credentials - you might not be a registered MyJFrog user. Please try again. ) and with a new account on JFrog which sent me an email requesting my company: To confirm this request, please include the license owner or any other support contact associated with your company's subscription approval in this email thread. Are the boost libraries at www.boost.org available for free or only under subscription? I found I can still download them from sourceforge, of course, but I would need to patch any dependencies that point to the older web-site. -- Gonzalo Garramuño ggarra13(a)gmail.com

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