On 9/9/2025 11:43 AM, Peter Xu wrote:
On Thu, Aug 14, 2025 at 10:17:15AM -0700, Steve Sistare wrote:
Allow a notifier to be added for multiple migration modes.
To allow a notifier to appear on multiple per-node lists, use
a generic list type. We can no longer use NotifierWithReturnList,
because it shoe horns the notifier onto a single list.
Signed-off-by: Steve Sistare <[email protected]>
---
include/migration/misc.h | 12 ++++++++++
migration/migration.c | 60 +++++++++++++++++++++++++++++++++++++-----------
2 files changed, 59 insertions(+), 13 deletions(-)
diff --git a/include/migration/misc.h b/include/migration/misc.h
index a261f99..592b930 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -95,7 +95,19 @@ void migration_add_notifier(NotifierWithReturn *notify,
void migration_add_notifier_mode(NotifierWithReturn *notify,
MigrationNotifyFunc func, MigMode mode);
+/*
+ * Same as migration_add_notifier, but applies to all @mode in the argument
+ * list. The list is terminated by -1 or MIG_MODE_ALL. For the latter,
+ * the notifier is added for all modes.
+ */
+void migration_add_notifier_modes(NotifierWithReturn *notify,
+ MigrationNotifyFunc func, MigMode mode, ...);
Would it be more common to pass in a bitmask instead (rather than n
parameters, plus a ending -1)?
Yes, but I defined it this way to avoid the common error of passing a bit
position
rather than a mask, eg:
A = 10
B = 7
migration_add_notifier_modes(A | B) WRONG
migration_add_notifier_modes(BIT(A) | BIT(B)) CORRECT
and because IMO passing A, B is slightly more readable than passing BIT(A) |
BIT(B).
Note the blocker functions also take modes using varargs, so using a bitmask for
the notifiers would give us two different representations.
- Steve
