Re: [PATCH v8 4/7] scripts: add block-coroutine-wrapper.py

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

15.09.2020 19:44, Vladimir Sementsov-Ogievskiy wrote:
> We have a very frequent pattern of creating coroutine from function
> with several arguments:
> 
>    - create structure to pack parameters
>    - create _entry function to call original function taking parameters
>      from struct
>    - do different magic to handle completion: set ret to NOT_DONE or
>      EINPROGRESS or use separate bool field
>    - fill the struct and create coroutine from _entry function and this
>      struct as a parameter
>    - do coroutine enter and BDRV_POLL_WHILE loop
> 
> Let's reduce code duplication by generating coroutine wrappers.
> 
> This patch adds scripts/block-coroutine-wrapper.py together with some
> friends, which will generate functions with declared prototypes marked
> by 'generated_co_wrapper' specifier.
> 
> The usage of new code generation is as follows:
> 
>      1. define somewhere
> 
>          int coroutine_fn bdrv_co_NAME(...) {...}
> 
>         function
> 
>      2. declare in some header file
> 
>          int generated_co_wrapper bdrv_NAME(...);
> 
>         function with same list of parameters. (you'll need to include
>         "block/generated-co-wrapper.h" to get the specifier)
> 
>      3. both declarations should be available through block/coroutines.h
>         header.
> 
>      4. add header with generated_co_wrapper declaration into
>         COROUTINE_HEADERS list in Makefile
> 
> Still, no function is now marked, this work is for the following
> commit.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com>
> ---
>   docs/devel/block-coroutine-wrapper.rst |  54 +++++++
>   block/block-gen.h                      |  49 +++++++
>   include/block/block.h                  |  10 ++
>   block/meson.build                      |   8 ++
>   scripts/block-coroutine-wrapper.py     | 187 +++++++++++++++++++++++++
>   5 files changed, 308 insertions(+)
>   create mode 100644 docs/devel/block-coroutine-wrapper.rst
>   create mode 100644 block/block-gen.h
>   create mode 100755 scripts/block-coroutine-wrapper.py


Also needed:

diff --git a/docs/devel/index.rst b/docs/devel/index.rst
index 04773ce076..cb0abe1e69 100644
--- a/docs/devel/index.rst
+++ b/docs/devel/index.rst
@@ -31,3 +31,4 @@ Contents:
     reset
     s390-dasd-ipl
     clocks
+   block-coroutine-wrapper

-- 
Best regards,
Vladimir