[Libguestfs] [PATCH libnbd v2 02/10] lib: Add macros to check if a callback is "null" or not, and set it to null.
Richard W.M. Jones
rjones at redhat.com
Thu Aug 15 09:56:13 UTC 2019
We have defined the concept of a "null callback" meaning one where the
.callback field = NULL. The first two new macros just test this
property, and the third one sets a callback to null.
This change is neutral refactoring.
---
generator/generator | 4 ++--
generator/states-reply-simple.c | 2 +-
generator/states-reply-structured.c | 11 ++++++-----
generator/states-reply.c | 2 +-
generator/states.c | 2 +-
lib/debug.c | 2 +-
lib/internal.h | 9 +++++++--
7 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/generator/generator b/generator/generator
index ca97910..98c99e0 100755
--- a/generator/generator
+++ b/generator/generator
@@ -3576,7 +3576,7 @@ let generate_lib_api_c () =
let value = match errcode with
| Some value -> value
| None -> assert false in
- pr " if (%s_callback.callback == NULL) {\n" cbname;
+ pr " if (CALLBACK_IS_NULL (%s_callback)) {\n" cbname;
pr " set_error (EFAULT, \"%%s cannot be NULL\", \"%s\");\n" cbname;
pr " ret = %s;\n" value;
pr " goto out;\n";
@@ -3689,7 +3689,7 @@ let generate_lib_api_c () =
List.iter (
function
| OClosure { cbname } ->
- pr ", %s_callback.callback ? \"<fun>\" : \"NULL\"" cbname
+ pr ", CALLBACK_IS_NULL (%s_callback) ? \"<fun>\" : \"NULL\"" cbname
| OFlags (n, _) -> pr ", %s" n
) optargs;
pr ");\n"
diff --git a/generator/states-reply-simple.c b/generator/states-reply-simple.c
index 2f83e6f..5e5b631 100644
--- a/generator/states-reply-simple.c
+++ b/generator/states-reply-simple.c
@@ -60,7 +60,7 @@
case 0:
/* guaranteed by START */
assert (cmd);
- if (cmd->cb.fn.chunk.callback) {
+ if (CALLBACK_IS_NOT_NULL (cmd->cb.fn.chunk)) {
int error = 0;
assert (cmd->error == 0);
diff --git a/generator/states-reply-structured.c b/generator/states-reply-structured.c
index a1641d4..85f0775 100644
--- a/generator/states-reply-structured.c
+++ b/generator/states-reply-structured.c
@@ -157,7 +157,7 @@
set_error (0, "invalid length in NBD_REPLY_TYPE_BLOCK_STATUS");
return 0;
}
- if (cmd->cb.fn.extent.callback == NULL) {
+ if (CALLBACK_IS_NULL (cmd->cb.fn.extent)) {
SET_NEXT_STATE (%.DEAD);
set_error (0, "not expecting NBD_REPLY_TYPE_BLOCK_STATUS here");
return 0;
@@ -293,7 +293,8 @@
offset, cmd->offset, cmd->count);
return 0;
}
- if (cmd->type == NBD_CMD_READ && cmd->cb.fn.chunk.callback) {
+ if (cmd->type == NBD_CMD_READ &&
+ CALLBACK_IS_NOT_NULL (cmd->cb.fn.chunk)) {
int scratch = error;
/* Different from successful reads: inform the callback about the
@@ -385,7 +386,7 @@
offset = be64toh (h->sbuf.sr.payload.offset_data.offset);
assert (cmd); /* guaranteed by CHECK */
- if (cmd->cb.fn.chunk.callback) {
+ if (CALLBACK_IS_NOT_NULL (cmd->cb.fn.chunk)) {
int error = cmd->error;
if (CALL_CALLBACK (cmd->cb.fn.chunk, cmd->data + (offset - cmd->offset),
@@ -446,7 +447,7 @@
* them as an extension, and this works even when length == 0.
*/
memset (cmd->data + offset, 0, length);
- if (cmd->cb.fn.chunk.callback) {
+ if (CALLBACK_IS_NOT_NULL (cmd->cb.fn.chunk)) {
int error = cmd->error;
if (CALL_CALLBACK (cmd->cb.fn.chunk,
@@ -479,7 +480,7 @@
assert (cmd); /* guaranteed by CHECK */
assert (cmd->type == NBD_CMD_BLOCK_STATUS);
- assert (cmd->cb.fn.extent.callback);
+ assert (CALLBACK_IS_NOT_NULL (cmd->cb.fn.extent));
assert (h->bs_entries);
assert (length >= 12);
diff --git a/generator/states-reply.c b/generator/states-reply.c
index 575a6d1..14bb010 100644
--- a/generator/states-reply.c
+++ b/generator/states-reply.c
@@ -168,7 +168,7 @@ save_reply_state (struct nbd_handle *h)
retire = cmd->type == NBD_CMD_DISC;
/* Notify the user */
- if (cmd->cb.completion.callback) {
+ if (CALLBACK_IS_NOT_NULL (cmd->cb.completion)) {
int error = cmd->error;
int r;
diff --git a/generator/states.c b/generator/states.c
index cfa9957..32bf975 100644
--- a/generator/states.c
+++ b/generator/states.c
@@ -121,7 +121,7 @@ void abort_commands (struct nbd_handle *h,
bool retire = cmd->type == NBD_CMD_DISC;
next = cmd->next;
- if (cmd->cb.completion.callback) {
+ if (CALLBACK_IS_NOT_NULL (cmd->cb.completion)) {
int error = cmd->error ? cmd->error : ENOTCONN;
int r;
diff --git a/lib/debug.c b/lib/debug.c
index eec2051..90d2f71 100644
--- a/lib/debug.c
+++ b/lib/debug.c
@@ -82,7 +82,7 @@ nbd_internal_debug (struct nbd_handle *h, const char *fs, ...)
if (r == -1)
goto out;
- if (h->debug_callback.callback)
+ if (CALLBACK_IS_NOT_NULL (h->debug_callback))
/* ignore return value */
CALL_CALLBACK (h->debug_callback, context, msg);
else
diff --git a/lib/internal.h b/lib/internal.h
index dc3676a..a18d581 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -273,6 +273,11 @@ struct command {
uint32_t error; /* Local errno value */
};
+/* Test if a callback is "null" or not, and set it to null. */
+#define CALLBACK_IS_NULL(cb) ((cb).callback == NULL)
+#define CALLBACK_IS_NOT_NULL(cb) (! CALLBACK_IS_NULL ((cb)))
+#define SET_CALLBACK_TO_NULL(cb) ((cb).callback = NULL)
+
/* Call a callback. */
#define CALL_CALLBACK(cb, ...) \
(cb).callback ((cb).user_data, ##__VA_ARGS__)
@@ -286,9 +291,9 @@ struct command {
#define FREE_CALLBACK(cb) \
do { \
nbd_completion_callback *_cb = (nbd_completion_callback *)&(cb); \
- if (_cb->callback != NULL && _cb->free != NULL) \
+ if (CALLBACK_IS_NOT_NULL (cb) && _cb->free != NULL) \
_cb->free (_cb->user_data); \
- _cb->callback = NULL; \
+ SET_CALLBACK_TO_NULL (cb); \
} while (0)
/* aio.c */
--
2.22.0
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