1 /* 2 * Simple transactions API 3 * 4 * Copyright (c) 2021 Virtuozzo International GmbH. 5 * 6 * Author: 7 * Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program. If not, see <http://www.gnu.org/licenses/>. 21 * 22 * 23 * = Generic transaction API = 24 * 25 * The intended usage is the following: you create "prepare" functions, which 26 * represents the actions. They will usually have Transaction* argument, and 27 * call tran_add() to register finalization callbacks. For finalization 28 * callbacks, prepare corresponding TransactionActionDrv structures. 29 * 30 * Then, when you need to make a transaction, create an empty Transaction by 31 * tran_create(), call your "prepare" functions on it, and finally call 32 * tran_abort() or tran_commit() to finalize the transaction by corresponding 33 * finalization actions in reverse order. 34 */ 35 36 #ifndef QEMU_TRANSACTIONS_H 37 #define QEMU_TRANSACTIONS_H 38 39 #include <gmodule.h> 40 41 typedef struct TransactionActionDrv { 42 void (*abort)(void *opaque); 43 void (*commit)(void *opaque); 44 void (*clean)(void *opaque); 45 } TransactionActionDrv; 46 47 typedef struct Transaction Transaction; 48 49 Transaction *tran_new(void); 50 void tran_add(Transaction *tran, TransactionActionDrv *drv, void *opaque); 51 void tran_abort(Transaction *tran); 52 void tran_commit(Transaction *tran); 53 54 static inline void tran_finalize(Transaction *tran, int ret) 55 { 56 if (ret < 0) { 57 tran_abort(tran); 58 } else { 59 tran_commit(tran); 60 } 61 } 62 63 #endif /* QEMU_TRANSACTIONS_H */ 64