qemu/block/block-gen.h
Vladimir Sementsov-Ogievskiy aaaa20b69b scripts: add block-coroutine-wrapper.py
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>
2020-10-05 10:59:06 +01:00

49 lines
1.7 KiB
C

/*
* Block coroutine wrapping core, used by auto-generated block/block-gen.c
*
* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2020 Virtuozzo International GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef BLOCK_BLOCK_GEN_H
#define BLOCK_BLOCK_GEN_H
#include "block/block_int.h"
/* Base structure for argument packing structures */
typedef struct BdrvPollCo {
BlockDriverState *bs;
bool in_progress;
int ret;
Coroutine *co; /* Keep pointer here for debugging */
} BdrvPollCo;
static inline int bdrv_poll_co(BdrvPollCo *s)
{
assert(!qemu_in_coroutine());
bdrv_coroutine_enter(s->bs, s->co);
BDRV_POLL_WHILE(s->bs, s->in_progress);
return s->ret;
}
#endif /* BLOCK_BLOCK_GEN_H */