qemu-e2k/include/qemu/transactions.h

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/*
* Simple transactions API
*
* Copyright (c) 2021 Virtuozzo International GmbH.
*
* Author:
* Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* = Generic transaction API =
*
* The intended usage is the following: you create "prepare" functions, which
* represents the actions. They will usually have Transaction* argument, and
* call tran_add() to register finalization callbacks. For finalization
* callbacks, prepare corresponding TransactionActionDrv structures.
*
* Then, when you need to make a transaction, create an empty Transaction by
* 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
#define QEMU_TRANSACTIONS_H
#include <gmodule.h>
typedef struct TransactionActionDrv {
void (*abort)(void *opaque);
void (*commit)(void *opaque);
void (*clean)(void *opaque);
} TransactionActionDrv;
typedef struct Transaction Transaction;
Transaction *tran_new(void);
void tran_add(Transaction *tran, TransactionActionDrv *drv, void *opaque);
void tran_abort(Transaction *tran);
void tran_commit(Transaction *tran);
static inline void tran_finalize(Transaction *tran, int ret)
{
if (ret < 0) {
tran_abort(tran);
} else {
tran_commit(tran);
}
}
#endif /* QEMU_TRANSACTIONS_H */