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[endian] [bikeshed] Conversion function naming discussion
by Beman Dawes 26 Jan '15

26 Jan '15

Naming is always a bike shed issue. I'm starting a separate thread for those who don't care can easily ignore it. The current names I'm least comfortable with are the conversion function names in the endian sub-namespace: big_to_native big_to_native_inplace native_to_big native_to_big_inplace little_to_native little_to_native_inplace native_to_little native_to_little_inplace conditional_reverse conditional_reverse_inplace These are quite explicit, but are a bit too long and awkward for my taste. I'd be willing to change these names if someone can come up with replacements that are shorter and less awkward, but still reasonable explicit. --Beman

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Boost 1.58 schedule available?
by Barend Gehrels 26 Jan '15

26 Jan '15

Hi, Boost 1.57 was released last November 3, so it is probably about the time to merge to master again? Is there already a schedule available? Thanks, Barend

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RFC Expression Validity Asserts
by Matt Calabrese 26 Jan '15

26 Jan '15

I've found it useful, especially in tests, to easily be able to do expression validity checking via SFINAE in a static assert. In other words, it's frequently useful to want to quickly test to make sure that a particular expression does or does not compile, similar in some ways to a concepts-lite usage pattern. The general idea is that you want to static assert that, given a series of object declarations of a specific type, a specified expression or series of expressions that deal with those objects would or would not cause substitution to fail had the object types been dependent on a template parameter. It internally relies on a macro that is invoked as such: ////////// IS_VALID_EXPR( (int) a, (float) b, // etc.. (a + b) (a - b) // etc. ) ////////// The above macro invocation results in an expression that is a constexpr bool which is true iff substitution would not fail. With the above macro, one can do, for instance: static_assert(IS_VALID_EXPR((const int) a, ++a), "Some error message."); I've found this pattern so common that I've created a macro that takes such a series of declarations and expressions and automatically produces a simple static_assert, outputting the declarations and the expression that did not compile. A slimmed down version of this macro can be toyed with via the link below (this slim version allows only one declaration and one expression per macro): http://ideone.com/RHd6FM Briefly, using the macro as such: STATIC_ASSERT_VALID ( (const int) a, ++a ); is able to produce a very human-readable error message: prog.cpp:58:1: error: static assertion failed: ******************** Given: const int a; The following expression was expected to compile but did not: ++a ******************** There is a similar macro for verifying that an expression does not compile, which I find is much more useful in practice. Notable is that the validity macro is an expression -- no statement or other declarations are introduced -- and the static assert macro produces a single static_assert. This means that you can use the assertion macro in the normal scopes that any static_assert can be used (namespace scope, class scope, function scope...). One limitation is that because it uses lambdas behind the scenes, the context in which the validity macro may be used is slightly restricted (I.E. it can't be used in an un-evaluated context). Is this something people would generally find useful? If it is considered generally useful, I don't think it's really worthy of its own library, so where would it go? Years ago I probably would have just assumed utility, but I'm not really sure where it would go in the modern boost structure. The slim version can easily have no dependencies, though the more general solution ideally depends on Boost.Preprocessor. The macros themselves require C++14, though slightly less-useful forms (ones that introduce additional declarations) could be made that would work in C++11. -- -Matt Calabrese

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Templight Installation - watch your version of svn
by Fletcher, John P 26 Jan '15

26 Jan '15

I have just been installing Templight and have hit a problem. Templight installation involves installing Clang and then applying a patch to it. Older versions of svn (before 1.7) do not have the svn patch command which is used on the installation. Unfortunately Ubuntu 12.04 has version 1.6.17 installed and does not offer an update. The solution to this has been to upgrade svn to a later version from WANdisco (see http://www.wandisco.com/subversion/download) After the upgrade, the patch command will still not run if the downloads of LLVM and Clang were done with the old version of svn. So the best thing is to upgrade svn before starting. Of course I did not know this at the time. I am sending this to save someone else the same trouble. Best wishes John

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[Test][Thread] Regression since 9 December?
by Vicente J. Botet Escriba 26 Jan '15

26 Jan '15

Hi, I'm getting a regression on all the Boost.Thread tests using Boost.Test to fail after this commit https://github.com/boostorg/test/commit/1eaffb96ceec82882a4e947c99735a37271…. See http://www.boost.org/development/tests/develop/developer/output/Sandia-clan…. |../../../boost/system/config.hpp:34:3: erreur: #error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK # error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK | When I comment the added lines everything works correctly as before. The Boost.Thread jamfile contains | <library>/boost/test//boost_unit_test_framework/<link>static | If I change it to | <library>/boost/test//boost_unit_test_framework | I get an error |darwin.link ../../../bin.v2/libs/thread/test/test_thread.test/darwin-4.9.1/debug/threading-multi/test_thread Undefined symbols for architecture x86_64: "_main", referenced from: start in crt1.10.6.o ld: symbol(s) not found for architecture x86_64 collect2: erreur: ld a retourné 1 code d'état d'exécution "/usr/gcc-4.9.1/bin/g++-4.9.1" -o "../../../bin.v2/libs/thread/test/test_thread.test/darwin-4.9.1/debug/threading-multi/test_thread" "../../../bin.v2/libs/thread/test/test_thread.test/darwin-4.9.1/debug/threading-multi/test_thread.o" "../../../bin.v2/libs/thread/test/test_thread.test/darwin-4.9.1/debug/threading-multi/winrt_init.o" "../../../bin.v2/libs/test/build/darwin-4.9.1/debug/threading-multi/libboost_unit_test_framework.dylib" "../../../bin.v2/libs/timer/build/darwin-4.9.1/debug/threading-multi/libboost_timer.dylib" "../../../bin.v2/libs/chrono/build/darwin-4.9.1/debug/threading-multi/libboost_chrono.dylib" "../../../bin.v2/libs/thread/build/darwin-4.9.1/debug/threading-multi/libboost_thread.dylib" "../../../bin.v2/libs/system/build/darwin-4.9.1/debug/threading-multi/libboost_system.dylib" -g | Do others observe the same? Do you have an idea how this can be fixed? Best, Vicente

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Boost build failure on master
by Michael Caisse 25 Jan '15

25 Jan '15

I normally just compile and test Spirit/Fusion tests using the super project layout. That works fine; however, I'm setting up Bamboo build artifacts for all of Boost to enable slicker testing. As a result, I'm just trying to build all of Boost after a checkout. I admit that I've never found this to work properly. I'm following what I think are the standard instructions [1]: (lets keep it simple with linux for now) git clone --recursive git@github.com:boostorg/boost.git cd boost ./bootstrap.sh ./b2 headers ./b2 The result: error: Name clash for '<pstage/lib>libboost_system.so.1.58.0' error: error: Tried to build the target twice, with property sets having error: these incompabile properties: error: error: - none error: - <address-model>64 <architecture>x86 error: error: Please make sure to have consistent requirements for these error: properties everywhere in your project, especially for install error: targets. Ideas? Thanks! Michael 1. <https://svn.boost.org/trac/boost/wiki/TryModBoost#InstallingModularBoost> -- Michael Caisse ciere consulting ciere.com

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[thread] Timed waits in Boost.Thread potentially fundamentally broken on Windows (possibly rest of Boost too)
by Niall Douglas 25 Jan '15

25 Jan '15

Dear all, CC: Stephan @ Microsoft - Stephan I'd love to know what the MSVC STL does below so we have the option of matching your behaviour. During investigating this bug report for Boost.Thread (https://svn.boost.org/trac/boost/ticket/9856) I have discovered a very worrying situation: it would appear that potentially all timed waits in Boost.Thread, and potentially in other parts of Boost, are broken on Windows Vista and later and have been for some years. The problem is in correct handling of timeouts. If one does this: mutex mtx; condition_variable cond; unique_lock<mutex> lk(mtx); assert(cv_status::timeout == cond.wait_for(lk, chrono::seconds(1))); ... one would reasonably expect occasional failures on POSIX due to spurious wakeups. It turns out that this also spuriously fails on Windows, which is a surprise probably to many as Windows hides signal handling (actually APCs) inside its Win32 APIs and automatically restarts the operation after interruption. There is, therefore, the potential that quite a lot of code written to use Boost.Thread on Windows makes the hard assumption that the assert above will never fail. The reason why Windows spuriously fails above isn't due to spurious wakeups, it is in fact due to changes in the Vista kernel scheduler as documented at https://technet.microsoft.com/en-us/magazine/2007.02.vistakernel.aspx. In essence, if you now ask Windows to go sleep for X milliseconds, Windows Vista onwards will in fact sleep for anywhere between zero and X+N milliseconds where N is some arbitrarily long value. In other words, timeouts in Windows are purely advisory, and are freely ignored by the Windows kernel from Vista onwards. You can test this for yourself using this little program which reduces the #9856 bug report to its Win32 API essentials: #include <windows.h> #include <stdio.h> #include <chrono> int main(void) { ULONG ulDelay_ms = 20; HANDLE hSemaphoreDelay = CreateSemaphore(NULL, 0, 1, NULL); for (size_t n = 0; n < 50; n++) { while (1) { auto begin = std::chrono::high_resolution_clock::now(); ULONG hr = WaitForSingleObject(hSemaphoreDelay, ulDelay_ms); auto end = std::chrono::high_resolution_clock::now(); auto diff = end - begin; if (hr == WAIT_ABANDONED) printf("Wait Abandoned "); else if (hr == WAIT_TIMEOUT) printf("Timed out "); else printf("Signaled "); DWORD lTDelta = std::chrono::duration_cast<std::chrono::milliseconds>(diff).count(); printf("Target Wait Interval: %u Real Wait Interval: %u (%u)\n", ulDelay_ms, lTDelta, diff.count()); if (lTDelta >= ulDelay_ms) break; } printf("\n"); } CloseHandle(hSemaphoreDelay); return 0; } As you'll see, actual time waited is anywhere between zero and 20 + N milliseconds where actual time waited is sometimes a whole integer multiple of the Windows kernel granularity (15 ms) or some fraction of that granularity. Most of the time he tries to hit what you asked for, but you get no guarantees. More detail about how and why Windows Vista onwards does this can be found at http://forum.sysinternals.com/bug-in-waitable-timers_topic16229.html. This raises the question about what to do with Boost.Thread. We have the following options: Option 1: Timed waits are allowed to spuriously fail by the standard, so we mark this as wontfix and move on. Anyone using the predicate timed waits has never seen a problem here anyway. Option 2: We loop waiting until steady_clock (really QueryPerformanceCounter under Boost) shows the requested timeout has passed. Problem: This wastes battery power and generates needless wakeups. A more intelligent implementation would ask Windows for the thread quanta and transform timeouts to match the Vista kernel scheduler in combination with always using deadline scheduling, but this would slow down the timed waits implementation. Option 3: We adjust Boost.Thread to return timeouts when Windows returns a timed out status code, even if the actual time waited is considerably lower than the time requested. Problem: some code written for POSIX where when you ask for a timeout you always get it may misbehave in this situation. Boost commmunity, I turn it over to you for advice! Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Review Wizard Status Report for January 2015
by Ron Garcia 24 Jan '15

24 Jan '15

============================================== Review Wizard Status Report for January 2015 ============================================== News ==== 1. Boost 1.56 Released November 2014. New Libraries: none 2. Sort Accepted. November 2014. 3. Compute Accepted. December 2014. Open Issues =========== The following libraries have review managers, but have not yet been scheduled for review: * Range Extensions - added May 2012; review manager: Neil Groves. The following libraries have been accepted to Boost, but have not yet been integrated into Boost Git: * Contract - accepted September 2012; author: Lorenzo Caminiti. * Sort - accepted November 2014: author: . * Compute - accepted December 2014: author: . The following libraries have been accepted and submitted to Boost Git, but have not yet appeared in a release: * Convert - accepted June 2014; author: Vladimir Batov. The following libraries have been accepted provisionally to Boost, but have not been submitted for mini-review and full acceptance: * Endian - accepted provisionally September 2011; author Beman Dawes. * Fiber - accepted provisionally January 2014; author Oliver Kowalke. General Announcements ===================== As always, we need experienced review managers. Please take a look at the list of libraries in need of managers and check out their descriptions. In general review managers are active boost participants, including library contributors, infrastructure contributors, and other mailing list participants with a substantial track record of constructive participation. If you can serve as review manager for any of them, email Ron Garcia or John Phillips, "rxg at cs dot ubc dot ca" and "johnphillipsithica at gmail dot com" respectively. We are also suffering from a lack of reviewers. While we all understand time pressures and the need to complete paying work, the strength of Boost is based on the detailed and informed reviews submitted by you. If you are interested in reviewing a library but won't have time during the review period, you can always prepare your review ahead of time. No rule says you can only work on a review during the review period. A link to this report will be posted to www.boost.org. If you would like us to make any modifications or additions to this report, please email Ron or John. The review schedule is an unordered list of the libraries awaiting review. As such, any library on the schedule can be reviewed once the developer is ready, a review manager has been secured, and the manager, developer, and wizards agree on a date to schedule the review. Review Schedule =============== * Join (M) * Sorting (M) * Quaternions, Vectors, Matrices (M) * Block Pointer (M) * Singularity (M) * Extended Complex Numbers (M) * Metaparse (M) * Boost.Range Extensions * Nowide (M) * Array (M) * STL Extensions (M) * Countertree (M) * Process (M) * Asynchronous File I/O (M) * Application (M) * Edit Distance (M) * Mixin (M) * Dependency Injection (M) * DLL (M) ``(M)`` marks libraries that need review managers. -------------------- Join ---- :Author: Yigong Liu :Review Manager: Needed :Download: http://channel.sourceforge.net/ :Description: Join is an asynchronous, message based C++ concurrency library based on join calculus. It is applicable both to multi-threaded applications and to the orchestration of asynchronous, event-based applications. It follows Comega's design and implementation and builds with Boost facilities. It provides a high level concurrency API with asynchronous methods, synchronous methods, and chords which are "join-patterns" defining the synchronization, asynchrony, and concurrency. Sorting ------- :Author: Steven Ross :Review Manager: Needed :Download: https://github.com/boost-vault/Sorting :Description: A grouping of 3 templated hybrid radix/comparison-based sorting algorithms that provide superior worst-case and average-case performance to std::sort: integer_sort, which sorts fixed-size data types that support a rightshift (default of >>) and a comparison (default of <) operator. float_sort, which sorts standard floating-point numbers by safely casting them to integers. string_sort, which sorts variable-length data types, and is optimized for 8-bit character strings. All 3 algorithms have O(n(k/s + s)) runtime where k is the number of bits in the data type and s is a constant, and limited memory overhead (in the kB for realistic inputs). In testing, integer_sort varies from 35% faster to 2X as fast as std::sort, depending on processor, compiler optimizations, and data distribution. float_sort is roughly 70% faster than std::sort. string_sort is roughly 2X as fast as std::sort. Quaternions, Vectors, Matrices ------------------------------ :Author: Emil Dotchevski :Review Manager: Needed :Download: http://www.revergestudios.com/boost-qvm/ :Description: QVM defines a set of generic functions and operator overloads for working with quaternions, vectors and matrices of static size. The library also defines vector and matrix data types, however it allows users to introduce their own types by specializing the q_traits, v_traits and m_traits templates. Block Pointer ------------- :Author: Phil Bouchard :Review Manager: Needed :Download: https://svn.boost.org/svn/boost/sandbox/block_ptr/ :Description: Deterministic memory manager of constant complexity capable of handling cyclic collections. Singularity ----------- :Author: Ben Robinson :Review Manager: Needed :Download: https://github.com/cppmaven/Singularity :Description: The Singularity Design Pattern allows you to restrict any class to a single instance. Unlike the infamous Singleton, Singularity gives you direct control over the lifetime of the object, does not require you to grant global access to the object, nor does it limit you to the default constructor for that object. Extended Complex Numbers ------------------------ :Author: Matthieu Schaller :Review Manager: Needed :Download: http://code.google.com/p/cpp-imaginary-numbers/ :Description: The library is an extension of the std::complex class addressing two issues: 1. The standard does not guaranty the behaviour of the complex class if instantiated with types other than float/double/long double. 2. Some calculation where pure imaginary numbers (i.e. multiples of sqrt(-1)) appear are unnecessarily slowed down due to the lack of support for these numbers. The code I submit contains two interleaved classes boost::complex and boost::imaginary which can be instantiated with any type T provided T overloads the usual arithmetic operators and some basic (real) mathematical functions depending on which complex function will be used. It is thus an extended version of Thorsten Ottosen's n1869 proposal (http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1869.html) Metaparse --------- :Author: Abel Sinkovics :Review Manager: Needed :Download: http://abel.web.elte.hu/metaparse/metaparse.zip :Description: Metaparse is a library for constructing parsers parsing at compile-time based on template metaprogramming. The parsers built with the library take boost::mpl::strings as input and can produce - types - objects (types with public static members) - callable C++ functions (types with public static method) - template metafunction classes as output (based on the input being parsed). On compilers supporting constexpr the library provides the following syntactic sugar for writing the input of the parsers: BOOST_STRING("this is a string") The library can be used for implementing DSLs in C++, including DSLs making C++ template metaprogramming easier (see examples). Range Extensions ---------------- :Author: Akira Takahashi :Review Manager: Neil Groves :Download: https://github.com/faithandbrave/OvenToBoost :Description: This project adds some features of the Oven Range Library to Boost.Range. Features: - Additional Range Adaptors (taken, taken_while, dropped, dropped_while, elements, elements_key, memoized, outdirected) - Extensions for using Lambda (regular function, regular operator) - Infinite Range (iteration function) - and additional range utilities. Nowide ------ :Author: Artyom Beilis :Review Manager: Needed :Download: http://cppcms.com/files/nowide/ :Description: This library makes cross platform Unicode aware programming easier. It provides an implementation of standard C and C++ library functions, such that their inputs are UTF-8 aware on Windows without requiring to use Wide API. Array ----- :Author: Brian Smith :Review Manager: Needed :Download: https://github.com/BrianJSmith/Array :Description: The array class is a C++11 compatible implementation of static multidimensional arrays. STL Extensions -------------- :Author: Vadim Stadnik :Review Manager: Needed :Download: https://github.com/vstadnik/stl_ext_adv_review :Description: The proposed library [stl_ext_adv] offers augmented array based B+ trees and STL containers that support the interfaces of the C++03 sequences and associative containers. The library offers a number of extensions and performance improvements that are not available in C++03 and C++11 standard containers. Countertree ----------- :Author: Francisco Jose Tapia :Review Manager: Needed :Download: https://dl.dropbox.com/u/8437476/works/countertree_code_doc.zip :Description: This library is an implementation of a binary red-black counter tree. This tree have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. COUNTERTREE This kind of trees have an additional counter in each leaf. This permit the access to the elements by the position, like in a vector. It is a random access container with random access iterators. With unordered information we have a vector with the same speed inserting and deleting in any position (O(log N)). With ordered information, we have the classes set, multiset, map and multimap, with identical interface than the STL classes, with the plus of access to the elements by position, like in a vector. The iterators are random access , and you can subtract them. SUBALLOCATOR The suballocator is a layer between the allocator and the data structures, compatible with any allocator with the STL definition. The suballocator replace to the allocator in the allocation of equal size elements. It provides speed, return the unused memory and decrease the memory used by the program and improve the cache performance due to the data locality improvement ( 30% of improvement of speed respect the std::allocator with GCC 4.7) Process ------- :Author: Boris Schaeling :Review Manager: Needed :Download: http://www.highscore.de/boost/process0.5/process.zip :Description: Boost.Process is a library to manage system processes. It can be used to: * create child processes * setup streams for child processes * communicate with child processes through streams (synchronously or asynchronously) * wait for processes to exit (synchronously or asynchronously) * terminate processes Asynchronous File I/O --------------------- :Author: Niall Douglas and Paul Kirth :Review Manager: Needed :Download: https://github.com/BoostGSoC/boost.afio/archive/boost-peer-review.tar.gz :Description: Boost.AFIO is a linear scalable, batch, chainable, asynchronous closure execution engine with an almost wait free implementation extending Boost.ASIO and Boost.Thread specialised as a portable asynchronous file i/o implementation library. Implementation of this first version has been kept as simple as possible (~ 1000 active LOC) at the cost of some performance, though with a good compiler you can expect 25-50% of the performance of using raw Boost.ASIO. Application ----------- :Author: Renato Tegon Forti :Review Manager: Needed :Download: https://github.com/retf/Boost.Application :Documentation: http://www.dokfile.com/appbeta4/docs/libs/application/doc/html/index.html :Description: Application provides an application environment, or start point to any people that want a basic infrastructure to build an system application on Windows or Unix Variants (e.g. Linux, MacOS). Application uses behaviours modeled using 'aspects' concept proposed by 'Vicente J. Botet Escriba', that allow easy extension and customization of library components. The application modes uses these components internally to achieve the user desirable behaviours. Application provide many useful ready-to-use features, e.g: * Run application as Windows Service; * Run application as UNIX/POSIX Daemon; * Plugin extension system; * Process(executable) Single instance Instantiation support; * Application SIGNAL/Callbacks customization; * Windows Service Setup feature; * And many others. Edit Distance ------------- :Author: Erik Erlandson :Review Manager: Needed :Download: https://github.com/erikerlandson/algorithm/tree/edit_distance/sequence :Description: The edit distance is the length of the shortest (or least-cost) edit script from one sequence to another, where an edit script is defined as a sequence of insertion, deletion and (optionally) substitution operations. The function implementing the edit distance is named edit_distance. This function will return the edit distance between two sequences, where sequences may be any valid range object supporting forward iteration. The edit_distance function will also, if requested, return the edit script. Mixin ----- :Author: Borislav Stanimirov :Download: https://github.com/iboB/boost.mixin :Documentation: http://ibob.github.io/boost.mixin/ :Review Manager: Needed :Description: Boost.Mixin is a library that allows the composition and modifications of polymorphic types at run time. Types and objects are constructed out of building blocks called mixins. The library uses the type boost::mixin::object as a placeholder, whose instances can be extended with existing classes (mixins), thus providing a particular instance with the functionality of all those types. Accessing the newly formed type's interface is made through messages: stand-alone functions generated by the library, which can be thought of as methods. This is given while also having full abstraction between the interface and the definition of types. An existing feature in another language similar to Boost.Mixin and also an inspiration for the library are the mixins in Ruby. The library also has similarities with the pattern entity-component-system. Dependency Injection -------------------- :Author: :Download: https://github.com/krzysztof-jusiak/di :Documentation: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html :Incubator: http://rrsd.com/blincubator.com/bi_library/di-dependency-injection/?gform_p… :Review Manager: Needed :Description: Boost.DI is a dependency injection library improving manual dependency injection by simplifying object instantiation with automatic dependencies injection. Using Boost.DI has many advantages over manual dependency injection. * Reduce boilerplate code (No factories, no objects creation in specific order) * Reduce cost of maintenance effort (Constructor signature change won't affect di configuration) * Reduce testing effort * Give better control of what and how is created (Policies, Providers) * Give better understanding about objects hierarchy (UML Dumper) DLL --- :Author: Antony Polukhin :Download: https://github.com/apolukhin/Boost.DLL :Documentation: http://apolukhin.github.io/Boost.DLL/index.html :Review Manager: Needed :Description: This library was designed to simplify plugin development using C++ in a portable cross-platform manner. Library provides a portable across platforms way to: * load libraries * import any native functions and variables * make alias names for C++ mangled functions and symbols * query libraries for sections and exported symbols * self loading and self querying * getting program and module location by exported symbol Libraries under development =========================== See The Boost Library Incubator Project at http://blincubator.com for discussion of libraries currently under development.

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clang-3.6 thread sanitizer complains on shared_ptr operations
by Gaetano Mendola 24 Jan '15

24 Jan '15

I'm using clang 3.6 with boost 1.54 $ clang-3.6 --version Ubuntu clang version 3.6.0-svn225356-1~exp1 (trunk) (based on LLVM 3.6.0) Target: x86_64-pc-linux-gnu Thread model: posix Compiling the code here: http://pastebin.com/zh0SPz5n $ clang++-3.6 -g main.cpp -lboost_system -lboost_thread -fsanitize=thread I get at runtime: ================== WARNING: ThreadSanitizer: data race (pid=5592) Write of size 8 at 0x7d080000cfe8 by thread T2 (mutexes: write M18): #0 operator delete(void*) <null> (a.out+0x00000045febb) #1 ~sp_counted_impl_p /usr/include/boost/smart_ptr/detail/sp_counted_impl.hpp:53 (a.out+0x0000004d15c9) #2 boost::detail::sp_counted_base::destroy() /usr/include/boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:126 (a.out+0x0000004cb77c) #3 boost::detail::sp_counted_base::weak_release() /usr/include/boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:160 (a.out+0x0000004c773f) #4 boost::detail::sp_counted_base::release() /usr/include/boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:147 (a.out+0x0000004c75e8) #5 ~shared_count /usr/include/boost/smart_ptr/detail/shared_count.hpp:371 (a.out+0x0000004c7550) #6 ~shared_ptr /usr/include/boost/smart_ptr/shared_ptr.hpp:722 (a.out+0x0000004cef59) #7 boost::shared_ptr<int>::operator=(boost::shared_ptr<int> const&) /usr/include/boost/smart_ptr/shared_ptr.hpp:507 (a.out+0x0000004cf1b7) #8 Consumer::consume(boost::shared_ptr<int>) /home/kalman/boost_sp_test/main.cpp:9 (a.out+0x0000004ced61) #9 Producer::operator()() /home/kalman/boost_sp_test/main.cpp:32 (a.out+0x0000004ceaba) #10 boost::detail::thread_data<boost::reference_wrapper<Producer> >::run() /usr/include/boost/thread/detail/thread.hpp:137 (a.out+0x0000004cc29e) #11 boost::this_thread::interruption_requested() <null> (libboost_thread.so.1.54.0+0x00000000ba49) Previous read of size 4 at 0x7d080000cfe8 by thread T1: #0 boost::detail::sp_counted_base::use_count() const /usr/include/boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:166 (a.out+0x0000004cb33e) #1 boost::detail::shared_count::use_count() const /usr/include/boost/smart_ptr/detail/shared_count.hpp:423 (a.out+0x0000004cf040) #2 boost::shared_ptr<int>::use_count() const /usr/include/boost/smart_ptr/shared_ptr.hpp:681 (a.out+0x0000004cefb9) #3 Consumer::operator()() /home/kalman/boost_sp_test/main.cpp:19 (a.out+0x0000004d4a29) #4 boost::detail::thread_data<boost::reference_wrapper<Consumer> >::run() /usr/include/boost/thread/detail/thread.hpp:137 (a.out+0x0000004d497e) #5 boost::this_thread::interruption_requested() <null> (libboost_thread.so.1.54.0+0x00000000ba49) Mutex M18 (0x7fff01719338) created at: #0 pthread_mutex_init <null> (a.out+0x0000004641e0) #1 mutex /usr/include/boost/thread/pthread/mutex.hpp:100 (a.out+0x0000004d1867) #2 Consumer /home/kalman/boost_sp_test/main.cpp:5 (a.out+0x0000004c6238) #3 main /home/kalman/boost_sp_test/main.cpp:41 (a.out+0x0000004c5903) Thread T2 (tid=5595, running) created by main thread at: #0 pthread_create <null> (a.out+0x000000462db1) #1 boost::thread::start_thread_noexcept() <null> (libboost_thread.so.1.54.0+0x00000000b3b8) #2 thread<boost::reference_wrapper<Producer> > /usr/include/boost/thread/detail/thread.hpp:302 (a.out+0x0000004c6639) #3 main /home/kalman/boost_sp_test/main.cpp:45 (a.out+0x0000004c59bd) Thread T1 (tid=5594, running) created by main thread at: #0 pthread_create <null> (a.out+0x000000462db1) #1 boost::thread::start_thread_noexcept() <null> (libboost_thread.so.1.54.0+0x00000000b3b8) #2 thread<boost::reference_wrapper<Consumer> > /usr/include/boost/thread/detail/thread.hpp:302 (a.out+0x0000004c6479) #3 main /home/kalman/boost_sp_test/main.cpp:44 (a.out+0x0000004c5968) SUMMARY: ThreadSanitizer: data race ??:0 operator delete(void*) ================== I believe this is a false alarm indeed the two threads are working on their own shared_ptr copy and thePtr shared pointer write/read in the two threads is protected with a mutex. I will open a ticket with clang folks if you recognize that is a false alarm, unless they are right and we have issue in shared_ptr implementation. Regards Gaetano -- cpp-today.blogspot.it --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com

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Debugging optimisation unstable code - Stack and other tools
by Fletcher, John P 24 Jan '15

24 Jan '15

I am working to get the bugs out of Phoenix and have a situation where some tests are optimisation unstable - they run on Clang 3.5 with -O1 but not -O2 and on gcc 4.9.0 with -O0 but not -O1. The higher optimisation gives an erroneous return value. I am looking for tools to work with this. I have found one called Stack (http://css.csail.mit.edu/stack/) I have built it but it only has instructions for whole projects rather than individual tests. It is hard to search for because the word 'stack' has lots of other meanings. Has anyone else used this or any other tools to solve this sort of problem? It is worth noting that some of the tests run fine on develop testing. That leads me to wonder if the level of optimisation used there is documented anywhere. Thanks John

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