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Can SIMD in boost unordered be disabled without disabling SIMD for full compile.
by Ivan Matek 13 Mar '24

13 Mar '24

Hi, I have some small maps where I am pretty sure SIMD tricks that are amazing in general will just slow down the lookups since I never lookup items not in the map and map is so small that benefits of not looking up into the big array and trashing the cache are miniscule. I know I can force compiler to not support SIMD with march, but I want to keep the SIMD optimizaitons for rest of the code, including large boost unordered objects. If you do not believe me I can write a custom benchmark, from what I see all benchmarks in docs start at 1E+4. P.S. I know I can just use an array, but I am in that "size range" where iteration becomes slower than a hash map. regards, Ivan

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Re: [Boost-users] Hi all,
by Pavel Vazharov 06 Mar '24

06 Mar '24

Hi, The most obvious error that I see is that you use `std::vector<char> buffer_data(1024);`as local variables and then they are destroyed but you continue to keep references to them via the boost::asio::buffer. The latter will not keep the `std::vector`s alive. You need to keep the std::vector as a member variable and only when you call the asio functions use the `boost::asio::buffer` function. Like m_socketHandler->socket.async_read_some(boost::asio::buffer(m_buffer_data), ... Where the m_buffer_data is a member variable of type `std::vector<char>`. HTH, Pavel.

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Hi all,
by Maria Tirindelli 06 Mar '24

06 Mar '24

I am experiencing an issue with boost 1.74 on linux. I am trying to have a server that asynchronously reads data from a tcp socket, and then closes when the client disconnect. My code looks like: class SimpleTCPServerTest::SocketHandler { public: explicit SocketHandler(boost::asio::ip::tcp::socket inputSocket ) : socket(std::move(inputSocket)) { socket.set_option(boost::asio::socket_base::keep_alive(true)); } boost::asio::ip::tcp::socket socket; }; SimpleTCPServerTest::SimpleTCPServerTest(std::string address, int port) : m_address(std::move(address)), m_port(port), m_ioc(boost::asio::io_context(1)), m_acceptor(boost::asio::ip::tcp::acceptor(m_ioc)), readTimer(m_ioc){ std::vector<char> buffer_data(1024); this->m_buffer = boost::asio::buffer(buffer_data); } bool SimpleTCPServerTest::open() { //auto const address = boost::asio::ip::make_address(ip); boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), static_cast<unsigned short>(m_port)); boost::system::error_code ec; // Open the acceptor m_acceptor.open(endpoint.protocol(), ec); if (ec) { LOG_ERROR("SimpleTCPServerTest", "Failed to open acceptor: " << ec.message()); return false; } // Allow address reuse m_acceptor.set_option(boost::asio::socket_base::reuse_address(true), ec); if (ec) { LOG_ERROR("SimpleTCPServerTest", "Failed to set reuse option in acceptor: " << ec.message()); return false; } // Bind to the server address m_acceptor.bind(endpoint, ec); if (ec) { LOG_ERROR("SimpleTCPServerTest", "Failed to bind acceptor: " << ec.message()); return false; } // Start listening for connections m_acceptor.listen(boost::asio::socket_base::max_listen_connections, ec); if (ec) { LOG_ERROR("SimpleTCPServerTest", "acceptor failed to start listening: " << ec.message()); return false; } m_acceptor.async_accept(boost::asio::make_strand(m_ioc), [this](boost::system::error_code ec, boost::asio::ip::tcp::socket socket) { on_accept(ec, std::move(socket)); }); m_iocRunThread = boost::thread([this] { m_ioc.run(); LOG_INFO("Exiting run thread"); }); return true; } } void SimpleTCPServerTest::on_accept(boost::system::error_code ec, boost::asio::ip::tcp::socket socket) { LOG_INFO("Client is connected"); m_socketHandler = std::make_unique<SocketHandler>(std::move(socket)); read(); } void SimpleTCPServerTest::read() { LOG_INFO("SimpleTCPServerTest", "Waiting a new message"); readTimer.expires_from_now(boost::posix_time::milliseconds(50)); readTimer.async_wait([this](boost::system::error_code ec) { LOG_INFO("Timer expired"); if (ec != boost::asio::error::operation_aborted) return; LOG_INFO("Timer expired with error"); m_socketHandler->socket.cancel(); }); m_socketHandler->socket.async_read_some(m_buffer, [this](const boost::system::error_code error, // Result of operation. std::size_t bytes_transferred) { if (error) { LOG_INFO("Client disconnected: " << error.message()); signalReadyToStop.emitSignal(); // HERE IT CRASHES return; } std::string dataString(boost::asio::buffer_cast<const char*>(m_buffer), bytes_transferred); LOG_INFO("Data was received: Size: " << bytes_transferred << " " << dataString); // Reset the buffer std::vector<char> buffer_data(1024); this->m_buffer = boost::asio::buffer(buffer_data); this->read(); }); } SimpleTCPServerTest::~SimpleTCPServerTest() { LOG_INFO("Terminating"); readTimer.cancel(); m_acceptor.cancel(); m_socketHandler->socket.cancel(); m_ioc.stop(); m_iocRunThread.join(); } The client is a simple python client that sends a few messages before disconnecting. my main.cpp is like: std::atomic<bool> m_runFlag = true; SimpleTCPServerTest server; server.signalReadyToStop.connect([&m_runFlag](){ m_runFlag =false; }); server.open(); while(m_runFlag) { std::this_thread::sleep_for(std::chrono::milliseconds(1000)); } LOG_INFO("Exiting test"); } The problem is that the code always crashes when returning from the async_read (indicated with "HERE IT CRASHES COMMENT") with error SIGABRT tcache_thread_shutdown(): unaligned tcache chunk detected. Even if I remove the return statement there, I still have the crash when calling m_ioc.stop(). It seems the error occurs when exiting from the m_iocRunThread (the "Exiting run thread" log is executed) What am I doing wrong? Thanks everyone

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tommath.h and boost\multiprecision\tommath.hpp
by Helmut Zeisel 28 Feb '24

28 Feb '24

I tried to use boost muiltiprecision with Visual Studio 2022, 64 bit and got the following error message: boost\multiprecision\tommath.hpp(444,36): error C2664: 'mp_err mp_radix_size(const mp_int *,int,size_t *)': cannot convert argument 3 from 'int *' to 'size_t *' I used tommath.h from https://github.com/libtom/libtommath/blob/develop/tommath.h that has (line 583) mp_err mp_radix_size(const mp_int *a, int radix, size_t *size) MP_WUR; but boost\multiprecision\tommath.hpp, lineS 443/444 are int s; detail::check_tommath_result(mp_radix_size(const_cast< ::mp_int*>(&m_data), base, &s)); I compared with cygwin, there tommath.h is mp_err mp_radix_size(const mp_int *a, int radix, int *size) MP_WUR; So I am not sure: do I need some different tommath for Visual Studio 2022, 64 bit, or should boost\multiprecision\tommath.hpp be changed? Helmut

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boost::stacktrace::stacktrace AND addr2line
by Foelsche, Peter 19 Feb '24

19 Feb '24

Dear All, Thanks for outstanding quality of boost! I'm using the stacktrace object together with debug info and BOOST_STACKTRACE_USE_ADDR2LINE defined. Would it be possible to cache the output of addr2line assuming that during the lifetime of the calling process the queried executable or shared objects do not change? Thanks Peter

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[boost::interprocess] between Rosetta and native apps - please advice how to fix issue
by Frank G 08 Feb '24

08 Feb '24

We need named IPC between Rosetta and native apps. In boost this seems not compatible, for example with Native app and we are unable to find the "MAP_FNAME" in find_and_construct on the Rosetta process. Works fine when each process is on same arch. " typedef boost::interprocess::managed_shared_memory shared_mem;shared_mem* seg;seg = new shared_mem(boost::interprocess::open_or_create, SHARED_FILENAME, F_MAX_TOTALBUF_SIZE );Img = seg->find_or_construct<imgtype>(MAP_FNAME)(); " Root cause seems to be MemoryAlgorithm and alignment.This has alignment of 16 for Rosetta and 8 for native.The 8 byte shift seems to be the root cause and I can see this when viewing memory. Looking deeper over the last few days we can see this from the difference in frontend size (from MemoryAlgorithm): "boost::interprocess::open_or_create This creates different sized frontend (iset_index 8 or 16)for Native vs Rosetta. frontend is defined from: boost::interprocess::ipcdetail::basic_managed_memory_impl<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index, 16> *const Then perform segment->find_or_construct<mtstruct>(MAP_FNAME)(); does not work across arch." Ideally we prefer not to write a bunch of complex custom allocators etc to get this to work with open_or_create and find_or_construct, and hoping there is some simplest solution. Questions: how can we workaround this? Can we force boost::interprocess::open_or_create to use same memory algo for both arch? Or force alignment to 16 for both arch?

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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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