| Message ID | 20211111120829.81329-8-hreitz@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: Attempt on fixing 030-reported errors | expand |
11.11.2021 15:08, Hanna Reitz wrote: > Invoke the transaction drivers' .clean() methods only after all > .commit() or .abort() handlers are done. > > This makes it easier to have nested transactions where the top-level > transactions pass objects to lower transactions that the latter can > still use throughout their commit/abort phases, while the top-level > transaction keeps a reference that is released in its .clean() method. > > (Before this commit, that is also possible, but the top-level > transaction would need to take care to invoke tran_add() before the > lower-level transaction does. This commit makes the ordering > irrelevant, which is just a bit nicer.) > > Signed-off-by: Hanna Reitz<hreitz@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
diff --git a/include/qemu/transactions.h b/include/qemu/transactions.h index 92c5965235..2f2060acd9 100644 --- a/include/qemu/transactions.h +++ b/include/qemu/transactions.h @@ -31,6 +31,9 @@ * tran_create(), call your "prepare" functions on it, and finally call * tran_abort() or tran_commit() to finalize the transaction by corresponding * finalization actions in reverse order. + * + * The clean() functions registered by the drivers in a transaction are called + * last, after all abort() or commit() functions have been called. */ #ifndef QEMU_TRANSACTIONS_H diff --git a/util/transactions.c b/util/transactions.c index d0bc9a3e73..2dbdedce95 100644 --- a/util/transactions.c +++ b/util/transactions.c @@ -61,11 +61,13 @@ void tran_abort(Transaction *tran) { TransactionAction *act, *next; - QSLIST_FOREACH_SAFE(act, &tran->actions, entry, next) { + QSLIST_FOREACH(act, &tran->actions, entry) { if (act->drv->abort) { act->drv->abort(act->opaque); } + } + QSLIST_FOREACH_SAFE(act, &tran->actions, entry, next) { if (act->drv->clean) { act->drv->clean(act->opaque); } @@ -80,11 +82,13 @@ void tran_commit(Transaction *tran) { TransactionAction *act, *next; - QSLIST_FOREACH_SAFE(act, &tran->actions, entry, next) { + QSLIST_FOREACH(act, &tran->actions, entry) { if (act->drv->commit) { act->drv->commit(act->opaque); } + } + QSLIST_FOREACH_SAFE(act, &tran->actions, entry, next) { if (act->drv->clean) { act->drv->clean(act->opaque); }
Invoke the transaction drivers' .clean() methods only after all .commit() or .abort() handlers are done. This makes it easier to have nested transactions where the top-level transactions pass objects to lower transactions that the latter can still use throughout their commit/abort phases, while the top-level transaction keeps a reference that is released in its .clean() method. (Before this commit, that is also possible, but the top-level transaction would need to take care to invoke tran_add() before the lower-level transaction does. This commit makes the ordering irrelevant, which is just a bit nicer.) Signed-off-by: Hanna Reitz <hreitz@redhat.com> --- include/qemu/transactions.h | 3 +++ util/transactions.c | 8 ++++++-- 2 files changed, 9 insertions(+), 2 deletions(-)