August 2022 - Boost-users - lists.preview.boost.org

TSan error with boost::interprocess::message_queue on macOS ARM
by vl01＠jens-carl.de 22 Sep '22

22 Sep '22

Hello List, I'm using the boost::interprocess::message_queue in a project and to verify everything is working I created a test case. In that test case I'm sending and receiving data via threads. The test passes on Linux, Windows with no sanitizer and also with AddressSanitizer and ThreadSanitizer. I recently added Apple Silicon (M1) to the test matrix and now the test run with ThreadSanitizer enabled fails. Is boost::interprocess::message_queue thread-safe? Can the reported TSan error be an false-positive? If it that case, what test can I run to verify that? I looked at code of atomic_cas32() and it uses the legacy built-in __sync_val_compare_and_swap(). Can it be that that built-in isn't supported on ARM? Is there a newer built-in which should be used? The reported TSan error: -- snip ================== WARNING: ThreadSanitizer: data race (pid=4146) Atomic write of size 4 at 0x000104af4028 by thread T2: #0 __tsan_atomic32_compare_exchange_val <null>:81245684 (libclang_rt.tsan_osx_dynamic.dylib:arm64e+0x57854) #1 boost::interprocess::ipcdetail::atomic_cas32(unsigned int volatile*, unsigned int, unsigned int) atomic.hpp:581 (tsan_boost:arm64+0x100005b30) Previous read of size 4 at 0x000104af4028 by thread T1: #0 boost::interprocess::ipcdetail::spin_mutex::try_lock() mutex.hpp:100 (tsan_boost:arm64+0x100006eb0) #1 void boost::interprocess::ipcdetail::try_based_lock<boost::interprocess::ipcdetail::spin_mutex>(boost::interprocess::ipcdetail::spin_mutex&) common_algorithms.hpp:62 (tsan_boost:arm64+0x100006e28) SUMMARY: ThreadSanitizer: data race atomic.hpp:581 in boost::interprocess::ipcdetail::atomic_cas32(unsigned int volatile*, unsigned int, unsigned int) -- snap Here is a code example which demonstrates the test case -- snip #include <boost/interprocess/ipc/message_queue.hpp> #include <iostream> #include <vector> #include <thread> #include <memory> struct MessageQueueImpl { MessageQueueImpl() { boost::interprocess::permissions file_permissions; file_permissions.set_permissions(0660); queue = std::make_unique<boost::interprocess::message_queue>(boost::interprocess::create_only, "tsanqueue", 10, 15, file_permissions); } std::unique_ptr<boost::interprocess::message_queue> queue; }; class MessageQueue { public: MessageQueue() : m_impl(std::make_unique<MessageQueueImpl>()) {} void send(const std::vector<uint8_t>& buffer) { m_impl->queue->send(buffer.data(), buffer.size(), 0); } void receive(std::vector<uint8_t>& buffer) { boost::interprocess::message_queue::size_type received_size = 0; buffer.resize(m_impl->queue->get_max_msg_size()); uint32_t prio; m_impl->queue->receive(buffer.data(), buffer.size(), received_size, prio); buffer.resize(received_size); } private: std::unique_ptr<MessageQueueImpl> m_impl; }; int main() { auto uut = std::make_unique<MessageQueue>(); std::thread sender([&uut]{ for(uint8_t i = 0; i < 3; ++i) { const std::vector<uint8_t> send_buffer = {i}; uut->send(send_buffer); } }); std::thread receiver([&uut]{ for(uint8_t i = 0; i < 3; ++i) { std::vector<uint8_t> receive_buffer; uint32_t prio; uut->receive(receive_buffer); std::cout << "buffer received:\n"; for (const auto i : receive_buffer) { std::cout << i << '\n'; } } }); if(sender.joinable()) { sender.join(); } if(receiver.joinable()) { receiver.join(); } return 0; } -- snap Cheers, Jens

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suspendable/resumable/prioritizable task dispatcher
by chris-boostusers＠stankevitz.com 31 Aug '22

31 Aug '22

Hi, Unfortunately I don't have the vocabulary needed to ask this question, but hopefully I'll learn it here. Does Boost have something that will help me with this problem: I have a list of CPU-bound tasks I need to perform. I'll list two of them here: a) compute first zillion digits of pi (low priority) b) add two plus two (high priority) I co_spawn (a). Later, while (a) is running, I co_spawn (b). (a) will be suspended at a "co_suspension_point" so that (b) can take over. Of course when (b) completes, (a) will resume. For bonus points, it will support multiple threads (probably easy) and a task's priority can change over time (probably hard). Thank you! Chris PS: I was recently blown away by the coroutine capability of ASIO: Talking Async Ep1: Why C++20 is the Awesomest Language for Network Programming https://www.youtube.com/watch?v=icgnqFM-aY4

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memory fault when passing var to a coroutine
by Piotr Gosławski 23 Aug '22

23 Aug '22

Hello, Using GCC 10.1 and Boost 1.77 I get a mem fault when executing the following code: #include <iostream> #include <boost/asio.hpp> #include <boost/asio/awaitable.hpp> struct TestStruct { std::string strField; }; boost::asio::awaitable<bool> TestFunction(TestStruct param) { std::cout << param.strField << std::endl; co_return true; } boost::asio::awaitable<void> TestCoroutine() { // This causes mem issue co_await TestFunction(TestStruct{"some string"}); } int main() { boost::asio::io_context io_context; boost::asio::co_spawn( io_context, []() { return TestCoroutine(); }, boost::asio::detached); io_context.run(); return 0; } Also tested with GCC 12.1 and Boost 1.79 - the result is the same ( https://godbolt.org/z/69MKbz7qE). Works if I use a temp variable: boost::asio::awaitable<void> TestCoroutine() { auto testStruct = TestStruct{"some string"}; co_await TestFunction(testStruct); } Or if I add a constructor to test struct: struct TestStruct { explicit TestStruct(const std::string& str) : strField(str) {} std::string strField; }; boost::asio::awaitable<void> TestCoroutine() { co_await TestFunction(TestStruct("some string")); } Is there any coroutines rule that I am violating here? If yes - is there any compiler option I can use to get a warning / error message? Full code with cmake can be found here: https://github.com/piotrgoslawski/mem_issue Thank you

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re：question about compile the boost head file.
by zyx_xzy＠sina.com 23 Aug '22

23 Aug '22

Respeced Mr.Emil, Thank you for your kindly reply. >I can't reproduce this with msvc versions available on godbolt: >https://godbolt.org/z/E8vYWTPf6 Exactly on godbolt,the compilers work well. I test this by myself. Once again, I change to the Microsoft Visual Studio Community 2019 ver. 16.11.18. And compile the program ,the error still exist. >Can you provide a complete error log, including source file and line of the >error? soruce file:info.hppsource code line no:145soruce code:error_info_container_impl * c=new error_info_container_impl;error log:C2259 “boost::exception_detail::error_info_container_impl”: cannot instantiate abstract class, test_boost D:\boost_1_79_0\boost\exception\info.hpp 145 Best regards, zhiyong

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question about compile the boost head file.
by zyx_xzy＠sina.com 20 Aug '22

20 Aug '22

hi anybody, I meet a problem when I try to compile the following program. #include <boost\exception\info.hpp> void main() { return; } The compile environment is Microsoft Visual Studio Community 2022 (64 位) - ver. 17.2.6.Compile error information is that C2259 “boost::exception_detail::error_info_container_impl”: cannot instantiate abstract class.I try many Boost versions,e.g.,boost 79,boost 65,boost64,boost60. They all give errors. Anybody can give me some suggestions? Best regards, zhiyong --------------------------------

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Abwesenheitsnachricht: question about compile the boost head file.
by Sören Textor 20 Aug '22

20 Aug '22

Derzeit bin ich nicht im Hause Ihre E-Mail wird nicht weitergeleitet. In dringenden Fällen bitte support(a)ditec-gmbh.de oder Telefonhotline +49-6221-31698-110 oder die Zentrale +49-6221-31698-0 kontaktieren. ----------------------------------------------- DiTEC Dr. Siegfried Kahlich & Dierk Langer GmbH Im Breitspiel 19 | 69126 Heidelberg | Germany Handelsregister | Mannheim | HRB 341229 Dieses Dokument ist vertraulich zu behandeln. Die Weitergabe, sowie Vervielfältigung, Verwertung und Mitteilung seines Inhalts ist nur mit unserer ausdrücklichen Genehmigung gestattet. Alle Rechte vorbehalten, insbesondere für den Fall der Schutzrechtsanmeldung. This document has to be treated confidentially. Its contents are not to be passed on, duplicated, exploited or disclosed without our express permission. All rights reserved, especially the right to apply for protective rights.

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[Boost.GIL] GCC 12.1.1 fails to compile boost.gil examples with -std=c++20
by B Aleck 18 Aug '22

18 Aug '22

Source: https://www.boost.org/doc/libs/1_80_0/libs/gil/doc/html/_downloads/resize.c… Compile with: g++ -std=c++20 -c gcc version: 12.1.1 The compile successes with -std=c++14 and -std=c++17, only fails with -std=c++20 Same error does not occur on clang Is this a boost bug or gcc bug?

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Enumerating network interfaces and querying their properties
by Kenneth Porter 14 Aug '22

14 Aug '22

Is there a portable way to enumerate network interfaces and query their properties? I don't see anything in ASIO for that. Any recommendations for other libraries? So far the closest I've come is Python's netifaces library. (Maybe someone would like to fork the Python library's C source and bring it into Boost?) <https://github.com/al45tair/netifaces> I've got an app that configures a remote IoT device on the same segment and then opens UDP listeners to listen for a stream of data from the device. The user specifies the hostname or address of the device. I'd like to be able to restrict the listeners to just the interface that the device is connected to. I have two interfaces, one for the LAN and one for devices, and I don't want to listen on the LAN interface. So ideally I'd get the list of interfaces and their addresses and netmasks. I think I also need the routing table. I can then identify which interface will receive the incoming UDP stream.

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Boost support for Arm64/Windows
by Jonathon Penix 12 Aug '22

12 Aug '22

Hi, I am interested in using Boost as a dependency on the Arm64/Windows platform but have been struggling to find information about the status for Boost libraries in general for Arm64/Windows. I am aware of a few specific libraries that directly mention their support status for Arm64/Windows (Boost.Atomic and Boost.Context, for example) or have had Arm64 related patches in their release notes (Boost.Build, for example). Are there any public boards/trackers for the current Boost status or outstanding issues for Boost on Arm64/Windows that I may have missed? Or should platform support be generally assumed to work outside of specific cases like Boost.Context so long as a conformant compiler is provided for the platform? Thanks!

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[release] Boost 1.80.0
by Glen Fernandes 11 Aug '22

11 Aug '22

Release 1.80.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.80.0> You can also download directly from: <https://boostorg.jfrog.io/artifactory/main/release/1.80.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. -- The Boost Release Team Marshall Clow, Glen Fernandes, Michael Caisse

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