On 6/9/20 9:13 AM, 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, use separate bool for void functions
Stale comment, now that you got rid of void functions earlier in the series.
- 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/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>
---
Makefile | 8 ++
block/block-gen.h | 55 +++++++++
include/block/generated-co-wrapper.h | 35 ++++++
block/Makefile.objs | 1 +
scripts/coroutine-wrapper.py | 174 +++++++++++++++++++++++++++
5 files changed, 273 insertions(+)
create mode 100644 block/block-gen.h
create mode 100644 include/block/generated-co-wrapper.h
create mode 100755 scripts/coroutine-wrapper.py
My python review is weak, but here goes.
+++ b/block/block-gen.h
+
+#include "block/block_int.h"
+
+/* This function is called at the end of generated coroutine entries. */
+static inline void bdrv_poll_co__on_exit(void)
+{
+ aio_wait_kick();
+}
I still think it's worth inlining aio_wait_kick() into the generated code,
instead of this one-line wrapper function. Patch below.
+
+/* 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 */
diff --git a/include/block/generated-co-wrapper.h
b/include/block/generated-co-wrapper.h
new file mode 100644
index 0000000000..62c6e053ba
--- /dev/null
+++ b/include/block/generated-co-wrapper.h
+#ifndef BLOCK_GENERATED_CO_WRAPPER_H
+#define BLOCK_GENERATED_CO_WRAPPER_H
+
+/*
+ * generated_co_wrapper
+ * Function specifier, which does nothing but marking functions to be
+ * generated by scripts/coroutine-wrapper.py
+ */
+#define generated_co_wrapper
Do we need a standalone header just for this definition, or could we stick it
in include/block/block.h? Also in my patch below.
diff --git a/scripts/coroutine-wrapper.py b/scripts/coroutine-wrapper.py
new file mode 100755
index 0000000000..dbe6fb97d9
--- /dev/null
+++ b/scripts/coroutine-wrapper.py
@@ -0,0 +1,174 @@
+#!/usr/bin/env python3
+"""Generate coroutine wrappers for block subsystem.
+def prettify(code: str) -> str:
+ """Prettify code using clang-format if available"""
+
+ try:
+ style = '{IndentWidth: 4, BraceWrapping: {AfterFunction: true}, ' \
+ 'BreakBeforeBraces: Custom, SortIncludes: false, ' \
+ 'MaxEmptyLinesToKeep: 2}'
It looks odd to pass in style as a string (requiring \-newline) rather than a
dict (which would not), but I guess that's because...
+ p = subprocess.run(['clang-format', f'-style={style}'], check=True,
...you have to stringify it anyway for the subprocess command line.
+class ParamDecl:
+ param_re = re.compile(r'(?P<decl>'
+ r'(?P<type>.*[ *])'
+ r'(?P<name>[a-z][a-z0-9_]*)'
I guess you're safe not including A-Z based on our coding style.
+ r')')
+
+ def __init__(self, param_decl: str) -> None:
+ m = self.param_re.match(param_decl.strip())
+ if m is None:
+ raise ValueError(f'Wrong parameter declaration: "{param_decl}"')
+ self.decl = m.group('decl')
+ self.type = m.group('type')
+ self.name = m.group('name')
+
+
+class FuncDecl:
+ def __init__(self, return_type: str, name: str, args: str) -> None:
+ self.return_type = return_type.strip()
+ self.name = name.strip()
+ self.args = [ParamDecl(arg.strip()) for arg in args.split(',')]
+
+ def gen_list(self, format: str) -> str:
+ return ', '.join(format.format_map(arg.__dict__) for arg in self.args)
+
+ def gen_block(self, format: str) -> str:
+ return '\n'.join(format.format_map(arg.__dict__) for arg in self.args)
+
+
+# Match wrappers declared with a generated_co_wrapper mark
+func_decl_re = re.compile(r'^int\s*generated_co_wrapper\s*'
+ r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
+ r'\((?P<args>[^)]*)\);$', re.MULTILINE)
+
Makes sense (requires coroutines to return int, but you fixed that earlier in
the series).
+
+def func_decl_iter(text: str) -> Iterator:
+ for m in func_decl_re.finditer(text):
+ yield FuncDecl(return_type='int',
+ name=m.group('wrapper_name'),
+ args=m.group('args'))
+
+
+def snake_to_camel(func_name: str) -> str:
...
Nothing else jumped out at me, so:
Reviewed-by: Eric Blake <eblake@redhat.com>
Still, here's the promised diffs I'm thinking of:
for 4/7
From 8c089d488ed8d9778fd5ee1f18dbc3845e4349f2 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Tue, 9 Jun 2020 17:13:26 +0300
Subject: [PATCH] fixup? scripts: add coroutine-wrapper.py
Worth squashing in to the coroutine generator?
Signed-off-by: Eric Blake <eblake@redhat.com>
---
scripts/coroutine-wrapper.py | 5 ++--
block/block-gen.h | 6 -----
include/block/block.h | 7 ++++++
include/block/generated-co-wrapper.h | 35 ----------------------------
4 files changed, 10 insertions(+), 43 deletions(-)
delete mode 100644 include/block/generated-co-wrapper.h
diff --git a/scripts/coroutine-wrapper.py b/scripts/coroutine-wrapper.py
index dbe6fb97d9bd..0c2cf13401ce 100755
--- a/scripts/coroutine-wrapper.py
+++ b/scripts/coroutine-wrapper.py
@@ -57,7 +57,8 @@ def gen_header():
#include "qemu/osdep.h"
#include "block/coroutines.h"
-#include "block/block-gen.h"\
+#include "block/block-gen.h"
+#include "block/block_int.h"\
"""
@@ -139,7 +140,7 @@ static void coroutine_fn {name}_entry(void *opaque)
s->poll_state.ret = {name}({ func.gen_list('s->{name}') });
s->poll_state.in_progress = false;
- bdrv_poll_co__on_exit();
+ aio_wait_kick();
}}
int {func.name}({ func.gen_list('{decl}') })
diff --git a/block/block-gen.h b/block/block-gen.h
index 482d06737d10..f80cf4897d11 100644
--- a/block/block-gen.h
+++ b/block/block-gen.h
@@ -28,12 +28,6 @@
#include "block/block_int.h"
-/* This function is called at the end of generated coroutine entries. */
-static inline void bdrv_poll_co__on_exit(void)
-{
- aio_wait_kick();
-}
-
/* Base structure for argument packing structures */
typedef struct BdrvPollCo {
BlockDriverState *bs;
diff --git a/include/block/block.h b/include/block/block.h
index 46965a77801c..59a002e06f23 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -10,6 +10,13 @@
#include "block/blockjob.h"
#include "qemu/hbitmap.h"
+/*
+ * generated_co_wrapper
+ * Function specifier, which does nothing but marking functions to be
+ * generated by scripts/coroutine-wrapper.py
+ */
+#define generated_co_wrapper
+
/* block.c */
typedef struct BlockDriver BlockDriver;
typedef struct BdrvChild BdrvChild;
diff --git a/include/block/generated-co-wrapper.h
b/include/block/generated-co-wrapper.h
deleted file mode 100644
index 62c6e053ba12..000000000000
--- a/include/block/generated-co-wrapper.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Block layer I/O functions
- *
- * 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_GENERATED_CO_WRAPPER_H
-#define BLOCK_GENERATED_CO_WRAPPER_H
-
-/*
- * generated_co_wrapper
- * Function specifier, which does nothing but marking functions to be
- * generated by scripts/coroutine-wrapper.py
- */
-#define generated_co_wrapper
-
-#endif /* BLOCK_GENERATED_CO_WRAPPER_H */
--