We have a very frequent pattern of creating a coroutine from a function
with several arguments:
- create a 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 with 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 the 'generated_co_wrapper' specifier.
The usage of new code generation is as follows:
1. define the coroutine function somewhere
int coroutine_fn bdrv_co_NAME(...) {...}
2. declare in some header file
int generated_co_wrapper bdrv_NAME(...);
with same list of parameters (generated_co_wrapper is
defined in "include/block/block.h").
3. Make sure the block_gen_c declaration in block/meson.build
mentions the file with your marker function.
Still, no function is now marked, this work is for the following
commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200924185414.28642-5-vsementsov@virtuozzo.com>
[Added encoding='utf-8' to open() calls as requested by Vladimir. Fixed
typo and grammar issues pointed out by Eric Blake. Removed clang-format
dependency that caused build test issues.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Vladimir Sementsov-Ogievskiy