Message du 22/03/11 21:50 De : "Oliver Kowalke" A : boost@lists.boost.org Copie à : Objet : Re: [boost] [context review] Review - alternative version available
Am 22.03.2011 21:20, schrieb Vicente BOTET:
Oliver, please it would be simpler if we review only one library. You could post here whatever you want, patches, explanations, but please don't request the reviewers to review another package.
ok
Could you elaborate more on the asm_impl point, I think I've missed something? Please post here whatever do you want to change.
Artyom has requested in its last postings that boost.context should compile the implementations for fcontext (using assembler) as well ucontext/Win Fiber (provided by the operating system) instead select one at compile-time with bjam options.
The user can now decide which impl should be choosen by selecting the corresponding class:
context< stack, asm_impl > : uses fcontext/assembler if available (Windows is currently disabled) context< stack, native_impl > : uses ucontext from C-lib on UNIX (if implemented) and Windows Fibers on Windows
I have a question with this design. Which will be the parameter used by Boost.Fiber, Boost.Taslet? Should them also provide this parameter? I really think this is not a good option. The good solution for me will be that the library doesn't let the user choose the implementation for a given platform, so ABI problem are avoided If I remember the problem comes from the fact that the assembler used can not be compiled conditionally as not included in a C++ file. If you want to preserve this file structure you will need a build system that let you know what are the best implementation you can provide on a specific platform.
I believe Artyom has right with his concerns about the ABI issues (binary compatiblity) - I would probably prefer the alternative solution. Because I got little feedback in the last year I'd like to use this review to get some comments for the alternative version.
I remember you already ask for such a solution some weeks ago.
Not exactly. What I was requesting is what you provide today with the context been non-copyable and non-movable. Maybe you are thinking to the fact I requested you to make a uniform C interface for fcontext and implement it with ucontext or fibers when the asm implementation is not available. This is in line with the request of Arytom to provide a C-interface. Best, Vicente