1 /***************************************************************************** 2 3 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved. 4 Copyright (c) 2015, 2020, MariaDB Corporation. 5 6 This program is free software; you can redistribute it and/or modify it under 7 the terms of the GNU General Public License as published by the Free Software 8 Foundation; version 2 of the License. 9 10 This program is distributed in the hope that it will be useful, but WITHOUT 11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 12 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along with 15 this program; if not, write to the Free Software Foundation, Inc., 16 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA 17 18 *****************************************************************************/ 19 20 /**************************************************//** 21 @file include/trx0roll.h 22 Transaction rollback 23 24 Created 3/26/1996 Heikki Tuuri 25 *******************************************************/ 26 27 #ifndef trx0roll_h 28 #define trx0roll_h 29 30 #include "trx0trx.h" 31 #include "mtr0mtr.h" 32 #include "trx0sys.h" 33 34 extern bool trx_rollback_is_active; 35 extern const trx_t* trx_roll_crash_recv_trx; 36 37 /*******************************************************************//** 38 Returns a transaction savepoint taken at this point in time. 39 @return savepoint */ 40 trx_savept_t 41 trx_savept_take( 42 /*============*/ 43 trx_t* trx); /*!< in: transaction */ 44 45 /** Report progress when rolling back a row of a recovered transaction. */ 46 void trx_roll_report_progress(); 47 /*******************************************************************//** 48 Rollback or clean up any incomplete transactions which were 49 encountered in crash recovery. If the transaction already was 50 committed, then we clean up a possible insert undo log. If the 51 transaction was not yet committed, then we roll it back. 52 @param all true=roll back all recovered active transactions; 53 false=roll back any incomplete dictionary transaction */ 54 void 55 trx_rollback_recovered(bool all); 56 /*******************************************************************//** 57 Rollback or clean up any incomplete transactions which were 58 encountered in crash recovery. If the transaction already was 59 committed, then we clean up a possible insert undo log. If the 60 transaction was not yet committed, then we roll it back. 61 Note: this is done in a background thread. 62 @return a dummy parameter */ 63 extern "C" 64 os_thread_ret_t 65 DECLARE_THREAD(trx_rollback_all_recovered)(void*); 66 /*********************************************************************//** 67 Creates a rollback command node struct. 68 @return own: rollback node struct */ 69 roll_node_t* 70 roll_node_create( 71 /*=============*/ 72 mem_heap_t* heap); /*!< in: mem heap where created */ 73 /***********************************************************//** 74 Performs an execution step for a rollback command node in a query graph. 75 @return query thread to run next, or NULL */ 76 que_thr_t* 77 trx_rollback_step( 78 /*==============*/ 79 que_thr_t* thr); /*!< in: query thread */ 80 /*******************************************************************//** 81 Rollback a transaction used in MySQL. 82 @return error code or DB_SUCCESS */ 83 dberr_t 84 trx_rollback_for_mysql( 85 /*===================*/ 86 trx_t* trx) /*!< in/out: transaction */ 87 MY_ATTRIBUTE((nonnull)); 88 /*******************************************************************//** 89 Rollback the latest SQL statement for MySQL. 90 @return error code or DB_SUCCESS */ 91 dberr_t 92 trx_rollback_last_sql_stat_for_mysql( 93 /*=================================*/ 94 trx_t* trx) /*!< in/out: transaction */ 95 MY_ATTRIBUTE((nonnull)); 96 /*******************************************************************//** 97 Rollback a transaction to a given savepoint or do a complete rollback. 98 @return error code or DB_SUCCESS */ 99 dberr_t 100 trx_rollback_to_savepoint( 101 /*======================*/ 102 trx_t* trx, /*!< in: transaction handle */ 103 trx_savept_t* savept) /*!< in: pointer to savepoint undo number, if 104 partial rollback requested, or NULL for 105 complete rollback */ 106 MY_ATTRIBUTE((nonnull(1))); 107 /*******************************************************************//** 108 Rolls back a transaction back to a named savepoint. Modifications after the 109 savepoint are undone but InnoDB does NOT release the corresponding locks 110 which are stored in memory. If a lock is 'implicit', that is, a new inserted 111 row holds a lock where the lock information is carried by the trx id stored in 112 the row, these locks are naturally released in the rollback. Savepoints which 113 were set after this savepoint are deleted. 114 @return if no savepoint of the name found then DB_NO_SAVEPOINT, 115 otherwise DB_SUCCESS */ 116 dberr_t 117 trx_rollback_to_savepoint_for_mysql( 118 /*================================*/ 119 trx_t* trx, /*!< in: transaction handle */ 120 const char* savepoint_name, /*!< in: savepoint name */ 121 int64_t* mysql_binlog_cache_pos) /*!< out: the MySQL binlog cache 122 position corresponding to this 123 savepoint; MySQL needs this 124 information to remove the 125 binlog entries of the queries 126 executed after the savepoint */ 127 MY_ATTRIBUTE((nonnull, warn_unused_result)); 128 /*******************************************************************//** 129 Creates a named savepoint. If the transaction is not yet started, starts it. 130 If there is already a savepoint of the same name, this call erases that old 131 savepoint and replaces it with a new. Savepoints are deleted in a transaction 132 commit or rollback. 133 @return always DB_SUCCESS */ 134 dberr_t 135 trx_savepoint_for_mysql( 136 /*====================*/ 137 trx_t* trx, /*!< in: transaction handle */ 138 const char* savepoint_name, /*!< in: savepoint name */ 139 int64_t binlog_cache_pos) /*!< in: MySQL binlog cache 140 position corresponding to this 141 connection at the time of the 142 savepoint */ 143 MY_ATTRIBUTE((nonnull)); 144 /*******************************************************************//** 145 Releases a named savepoint. Savepoints which 146 were set after this savepoint are deleted. 147 @return if no savepoint of the name found then DB_NO_SAVEPOINT, 148 otherwise DB_SUCCESS */ 149 dberr_t 150 trx_release_savepoint_for_mysql( 151 /*============================*/ 152 trx_t* trx, /*!< in: transaction handle */ 153 const char* savepoint_name) /*!< in: savepoint name */ 154 MY_ATTRIBUTE((nonnull, warn_unused_result)); 155 /*******************************************************************//** 156 Frees savepoint structs starting from savep. */ 157 void 158 trx_roll_savepoints_free( 159 /*=====================*/ 160 trx_t* trx, /*!< in: transaction handle */ 161 trx_named_savept_t* savep); /*!< in: free all savepoints > this one; 162 if this is NULL, free all savepoints 163 of trx */ 164 /** Rollback node states */ 165 enum roll_node_state { 166 ROLL_NODE_NONE = 0, /*!< Unknown state */ 167 ROLL_NODE_SEND, /*!< about to send a rollback signal to 168 the transaction */ 169 ROLL_NODE_WAIT /*!< rollback signal sent to the 170 transaction, waiting for completion */ 171 }; 172 173 /** Rollback command node in a query graph */ 174 struct roll_node_t{ 175 que_common_t common; /*!< node type: QUE_NODE_ROLLBACK */ 176 enum roll_node_state state; /*!< node execution state */ 177 const trx_savept_t* savept; /*!< savepoint to which to 178 roll back, in the case of a 179 partial rollback */ 180 que_thr_t* undo_thr;/*!< undo query graph */ 181 }; 182 183 /** A savepoint set with SQL's "SAVEPOINT savepoint_id" command */ 184 struct trx_named_savept_t{ 185 char* name; /*!< savepoint name */ 186 trx_savept_t savept; /*!< the undo number corresponding to 187 the savepoint */ 188 int64_t mysql_binlog_cache_pos; 189 /*!< the MySQL binlog cache position 190 corresponding to this savepoint, not 191 defined if the MySQL binlogging is not 192 enabled */ 193 UT_LIST_NODE_T(trx_named_savept_t) 194 trx_savepoints; /*!< the list of savepoints of a 195 transaction */ 196 }; 197 198 #endif 199