[Tarantool-patches] [PATCH] evio: workaround for wsl1 so_linger assertion

[Cyrill Gorcunov]

On Mon, Mar 16, 2020 at 06:25:22PM +0300, Timur Safin wrote:
> SO_LINGER makes no much sense for unix-sockets, and Microsoft WSL
> is returning EINVAL if setsockopts called for SO_LINGER over unix
> sockets:
> 
>   [004] 2020-03-11 18:42:29.592 [29182] main/102/app sio.c:169 !> SystemError setsockopt(SO_LINGER), called on fd 16, aka
>   [004] 2020-03-11 18:42:29.592 [29182] main/102/app F> can't initialize storage: setsockopt(SO_LINGER), called on fd 16,
>   [004] 2020-03-11 18:42:29.592 [29182] main/102/app F> can't initialize storage: setsockopt(SO_LINGER), called on fd 16,
> 
> And it's sort of correct here, but the problem is Linux is simply
> silently ignoring it, which passes tests.
> 
> After much debates we decided to work-around this case via CMAKE
> define.
> 
> NB! In a future (April/May 2020), when WSL2 with full Linux kernel
> would be released we should disable this check.
> ---
> 
> This patch replaces prior one tsafin/gh-4659-wsl-no-linger-assert because original
> approach considered unsafe, and we rather want to workaround it via CMake instead.
> 
> 
> Branch: https://github.com/tarantool/tarantool/tree/tsafin/wsl1-no-linger-assert
> 
>  cmake/os.cmake      | 13 +++++++++++++
>  src/lib/core/evio.c |  2 ++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/cmake/os.cmake b/cmake/os.cmake
> index 0ed554b9b..ee8870d21 100644
> --- a/cmake/os.cmake
> +++ b/cmake/os.cmake
> @@ -11,6 +11,15 @@ if (${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
>  # (see man page for feature_test_macros).
>      add_definitions("-D_FILE_OFFSET_BITS=64")
>      find_package_message(PLATFORM "Building for Linux" "${CMAKE_SYSTEM_NAME}")
> +
> +    # There are some subtle differences in Linux kernel calls
> +    # implementation under WSL1 (which should go away with WSL2 kernel)
> +    # so for a moment we introduce a way to distinguish Linux and
> +    # Microsoft/WSL1
> +    if (${CMAKE_SYSTEM} MATCHES "Linux-.*-Microsoft")
> +        add_definitions("-DTARANTOOL_WSL_WORKAROUND_ENABLED=1")
> +    endif()
> +

Great! Thanks a huge, Timur! Since you mentioned WSL2 maybe we should
name it -DTARANTOOL_WSL_1 ? I don't insist though.

Acked-by: Cyrill Gorcunov <gorcunov at gmail.com>