1 /***************************************************************************** 2 3 Copyright (c) 1996, 2019, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License, version 2.0, as published by the 7 Free Software Foundation. 8 9 This program is also distributed with certain software (including but not 10 limited to OpenSSL) that is licensed under separate terms, as designated in a 11 particular file or component or in included license documentation. The authors 12 of MySQL hereby grant you an additional permission to link the program and 13 your derivative works with the separately licensed software that they have 14 included with MySQL. 15 16 This program is distributed in the hope that it will be useful, but WITHOUT 17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 18 FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, 19 for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 25 *****************************************************************************/ 26 27 /** @file include/trx0roll.h 28 Transaction rollback 29 30 Created 3/26/1996 Heikki Tuuri 31 *******************************************************/ 32 33 #ifndef trx0roll_h 34 #define trx0roll_h 35 36 #include "mtr0mtr.h" 37 #include "trx0sys.h" 38 #include "trx0trx.h" 39 #include "trx0types.h" 40 #include "univ.i" 41 42 #ifdef UNIV_HOTBACKUP 43 #include "que0que.h" 44 #endif /* UNIV_HOTBACKUP */ 45 46 /** Determines if this transaction is rolling back an incomplete transaction 47 in crash recovery. 48 @return true if trx is an incomplete transaction that is being rolled 49 back in crash recovery */ 50 ibool trx_is_recv(const trx_t *trx); /*!< in: transaction */ 51 /** Returns a transaction savepoint taken at this point in time. 52 @return savepoint */ 53 trx_savept_t trx_savept_take(trx_t *trx); /*!< in: transaction */ 54 55 /** Get next undo log record from redo and noredo rollback segments. 56 @return undo log record copied to heap, NULL if none left, or if the 57 undo number of the top record would be less than the limit */ 58 trx_undo_rec_t *trx_roll_pop_top_rec_of_trx( 59 trx_t *trx, /*!< in: transaction */ 60 undo_no_t limit, /*!< in: least undo number we need */ 61 roll_ptr_t *roll_ptr, /*!< out: roll pointer to undo record */ 62 mem_heap_t *heap); /*!< in: memory heap where copied */ 63 64 /** Rollback or clean up any incomplete transactions which were 65 encountered in crash recovery. If the transaction already was 66 committed, then we clean up a possible insert undo log. If the 67 transaction was not yet committed, then we roll it back. */ 68 void trx_rollback_or_clean_recovered( 69 ibool all); /*!< in: FALSE=roll back dictionary transactions; 70 TRUE=roll back all non-PREPARED transactions */ 71 72 /** Rollback or clean up any incomplete transactions which were 73 encountered in crash recovery. If the transaction already was 74 committed, then we clean up a possible insert undo log. If the 75 transaction was not yet committed, then we roll it back. 76 Note: this is done in a background thread. */ 77 void trx_recovery_rollback_thread(); 78 79 /** Creates a rollback command node struct. 80 @return own: rollback node struct */ 81 roll_node_t *roll_node_create( 82 mem_heap_t *heap); /*!< in: mem heap where created */ 83 /** Performs an execution step for a rollback command node in a query graph. 84 @return query thread to run next, or NULL */ 85 que_thr_t *trx_rollback_step(que_thr_t *thr); /*!< in: query thread */ 86 /** Rollback a transaction used in MySQL. 87 @return error code or DB_SUCCESS */ 88 dberr_t trx_rollback_for_mysql(trx_t *trx); /*!< in/out: transaction */ 89 /** Rollback the latest SQL statement for MySQL. 90 @return error code or DB_SUCCESS */ 91 dberr_t trx_rollback_last_sql_stat_for_mysql( 92 trx_t *trx); /*!< in/out: transaction */ 93 /** Rollback a transaction to a given savepoint or do a complete rollback. 94 @return error code or DB_SUCCESS */ 95 dberr_t trx_rollback_to_savepoint( 96 trx_t *trx, /*!< in: transaction handle */ 97 trx_savept_t *savept); /*!< in: pointer to savepoint undo number, if 98 partial rollback requested, or NULL for 99 complete rollback */ 100 /** Rolls back a transaction back to a named savepoint. Modifications after the 101 savepoint are undone but InnoDB does NOT release the corresponding locks 102 which are stored in memory. If a lock is 'implicit', that is, a new inserted 103 row holds a lock where the lock information is carried by the trx id stored in 104 the row, these locks are naturally released in the rollback. Savepoints which 105 were set after this savepoint are deleted. 106 @return if no savepoint of the name found then DB_NO_SAVEPOINT, 107 otherwise DB_SUCCESS */ 108 dberr_t trx_rollback_to_savepoint_for_mysql( 109 trx_t *trx, /*!< in: transaction handle */ 110 const char *savepoint_name, /*!< in: savepoint name */ 111 int64_t *mysql_binlog_cache_pos) /*!< out: the MySQL binlog cache 112 position corresponding to this 113 savepoint; MySQL needs this 114 information to remove the 115 binlog entries of the queries 116 executed after the savepoint */ 117 MY_ATTRIBUTE((warn_unused_result)); 118 /** Creates a named savepoint. If the transaction is not yet started, starts it. 119 If there is already a savepoint of the same name, this call erases that old 120 savepoint and replaces it with a new. Savepoints are deleted in a transaction 121 commit or rollback. 122 @return always DB_SUCCESS */ 123 dberr_t trx_savepoint_for_mysql( 124 trx_t *trx, /*!< in: transaction handle */ 125 const char *savepoint_name, /*!< in: savepoint name */ 126 int64_t binlog_cache_pos); /*!< in: MySQL binlog cache 127 position corresponding to this 128 connection at the time of the 129 savepoint */ 130 /** Releases a named savepoint. Savepoints which 131 were set after this savepoint are deleted. 132 @return if no savepoint of the name found then DB_NO_SAVEPOINT, 133 otherwise DB_SUCCESS */ 134 dberr_t trx_release_savepoint_for_mysql( 135 trx_t *trx, /*!< in: transaction handle */ 136 const char *savepoint_name) /*!< in: savepoint name */ 137 MY_ATTRIBUTE((warn_unused_result)); 138 /** Frees savepoint structs starting from savep. */ 139 void trx_roll_savepoints_free( 140 trx_t *trx, /*!< in: transaction handle */ 141 trx_named_savept_t *savep); /*!< in: free all savepoints > this one; 142 if this is NULL, free all savepoints 143 of trx */ 144 /** Rollback node states */ 145 enum roll_node_state { 146 ROLL_NODE_NONE = 0, /*!< Unknown state */ 147 ROLL_NODE_SEND, /*!< about to send a rollback signal to 148 the transaction */ 149 ROLL_NODE_WAIT /*!< rollback signal sent to the 150 transaction, waiting for completion */ 151 }; 152 153 /** Rollback command node in a query graph */ 154 struct roll_node_t { 155 que_common_t common; /*!< node type: QUE_NODE_ROLLBACK */ 156 enum roll_node_state state; /*!< node execution state */ 157 bool partial; /*!< TRUE if we want a partial 158 rollback */ 159 trx_savept_t savept; /*!< savepoint to which to 160 roll back, in the case of a 161 partial rollback */ 162 que_thr_t *undo_thr; /*!< undo query graph */ 163 }; 164 165 /** A savepoint set with SQL's "SAVEPOINT savepoint_id" command */ 166 struct trx_named_savept_t { 167 char *name; /*!< savepoint name */ 168 trx_savept_t savept; /*!< the undo number corresponding to 169 the savepoint */ 170 int64_t mysql_binlog_cache_pos; 171 /*!< the MySQL binlog cache position 172 corresponding to this savepoint, not 173 defined if the MySQL binlogging is not 174 enabled */ 175 UT_LIST_NODE_T(trx_named_savept_t) 176 trx_savepoints; /*!< the list of savepoints of a 177 transaction */ 178 }; 179 180 #include "trx0roll.ic" 181 182 #endif 183