GetLogicalProcessor isn't available for Windows platform less or equals to 0x0502

[steve.tousignant@…]

I've runned into an issue while using boost 1.56.0 and boost 1.57.0 while ours software was deployed on a Windows XP SP2. When using the threading library from boost, we have found out that it was using a feature only available on Windows XP SP3 and higher.

The effect are that the software built with Boost 1.56.0 and boost 1.57.0 refuse to start even after we force the feature set of windows XP to be used by the Windows Platform SDK.

I will attach a patch as a proposed fix for future version of boost.

[steve.tousignant@…]

Proposed patch for boost threading

[viboes]

Please, don't use the threads component but the thread one.

[viboes]

The current code is

    unsigned thread::physical_concurrency() BOOST_NOEXCEPT
    {
#if BOOST_PLAT_WINDOWS_RUNTIME || (defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR))
        return hardware_concurrency();
#else
        unsigned cores = 0;
        DWORD size = 0;

        GetLogicalProcessorInformation(NULL, &size);
        if (ERROR_INSUFFICIENT_BUFFER != GetLastError())
            return 0;

        std::vector<SYSTEM_LOGICAL_PROCESSOR_INFORMATION> buffer(size);
        if (GetLogicalProcessorInformation(&buffer.front(), &size) == FALSE)
            return 0;

        const size_t Elements = size / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION);

        for (size_t i = 0; i < Elements; ++i) {
            if (buffer[i].Relationship == RelationProcessorCore)
                ++cores;
        }
        return cores;
#endif
    }

Does it works for you?

[viboes]

PING !!!

[viboes]

#11683 describes the history of this function and how we rolled back a fix.

I've update the develop branch.

​https://github.com/boostorg/thread/commit/9a8759a3dda2c63342d55d5e97ed906826cee981

[Daniel]

Please also take into account the issue with comments after preprocessor continuation for VS2010 (comment:6:ticket:10824): commit/8e1be55c6d560c44fb07cc497a3480527957576c