diff --git a/innobase/include/lock0lock.h b/innobase/include/lock0lock.h index f8435e14d97666143c58790a62e67dd4247ac859..ff5b6aae02e947d5bd007a2e9bc2d3bbaf255008 100644 --- a/innobase/include/lock0lock.h +++ b/innobase/include/lock0lock.h @@ -463,13 +463,32 @@ lock_rec_hash( ulint space, /* in: space */ ulint page_no);/* in: page number */ /************************************************************************* -Gets the table covered by an IX table lock. */ +Gets the source table of an ALTER TABLE transaction. The table must be +covered by an IX or IS table lock. */ dict_table_t* -lock_get_ix_table( -/*==============*/ - /* out: the table covered by the lock */ - lock_t* lock); /* in: table lock */ +lock_get_src_table( +/*===============*/ + /* out: the source table of transaction, + if it is covered by an IX or IS table lock; + dest if there is no source table, and + NULL if the transaction is locking more than + two tables or an inconsistency is found */ + trx_t* trx, /* in: transaction */ + dict_table_t* dest, /* in: destination of ALTER TABLE */ + ulint* mode); /* out: lock mode of the source table */ +/************************************************************************* +Determine if the given table is exclusively "owned" by the given +transaction, i.e., transaction holds LOCK_IX and possibly LOCK_AUTO_INC +on the table. */ + +ibool +lock_table_exclusive( +/*=================*/ + /* out: TRUE if table is only locked by trx, + with LOCK_IX, and possibly LOCK_AUTO_INC */ + dict_table_t* table, /* in: table */ + trx_t* trx); /* in: transaction */ /************************************************************************* Checks that a transaction id is sensible, i.e., not in the future. */ diff --git a/innobase/include/row0mysql.h b/innobase/include/row0mysql.h index 73f41dea0dafc723315421676ce553756669066a..f47ce74ce3791106ce9c6ee3f42ec1abe2d5ca69 100644 --- a/innobase/include/row0mysql.h +++ b/innobase/include/row0mysql.h @@ -177,10 +177,12 @@ row_lock_table_for_mysql( /* out: error code or DB_SUCCESS */ row_prebuilt_t* prebuilt, /* in: prebuilt struct in the MySQL table handle */ - dict_table_t* table); /* in: table to LOCK_IX, or NULL + dict_table_t* table, /* in: table to lock, or NULL if prebuilt->table should be locked as LOCK_TABLE_EXP | prebuilt->select_lock_type */ + ulint mode); /* in: lock mode of table */ + /************************************************************************* Does an insert for MySQL. */ diff --git a/innobase/lock/lock0lock.c b/innobase/lock/lock0lock.c index 78a78c9dd95d5968cad788f734f03f707e4345f3..16c4ddfd96d507247e8d49a3035cc1365545c906 100644 --- a/innobase/lock/lock0lock.c +++ b/innobase/lock/lock0lock.c @@ -395,19 +395,6 @@ lock_rec_get_nth_bit( return(ut_bit_get_nth(b, bit_index)); } -/************************************************************************* -Gets the table covered by an IX table lock. */ - -dict_table_t* -lock_get_ix_table( -/*==============*/ - /* out: the table covered by the lock */ - lock_t* lock) /* in: table lock */ -{ - ut_a(lock->type_mode == (LOCK_TABLE | LOCK_IX)); - return(lock->un_member.tab_lock.table); -} - /*************************************************************************/ #define lock_mutex_enter_kernel() mutex_enter(&kernel_mutex) @@ -614,6 +601,128 @@ lock_get_wait( return(FALSE); } +/************************************************************************* +Gets the source table of an ALTER TABLE transaction. The table must be +covered by an IX or IS table lock. */ + +dict_table_t* +lock_get_src_table( +/*===============*/ + /* out: the source table of transaction, + if it is covered by an IX or IS table lock; + dest if there is no source table, and + NULL if the transaction is locking more than + two tables or an inconsistency is found */ + trx_t* trx, /* in: transaction */ + dict_table_t* dest, /* in: destination of ALTER TABLE */ + ulint* mode) /* out: lock mode of the source table */ +{ + dict_table_t* src; + lock_t* lock; + + src = NULL; + *mode = LOCK_NONE; + + for (lock = UT_LIST_GET_FIRST(trx->trx_locks); + lock; + lock = UT_LIST_GET_NEXT(trx_locks, lock)) { + lock_table_t* tab_lock; + ulint lock_mode; + if (!(lock_get_type(lock) & LOCK_TABLE)) { + /* We are only interested in table locks. */ + continue; + } + tab_lock = &lock->un_member.tab_lock; + if (dest == tab_lock->table) { + /* We are not interested in the destination table. */ + continue; + } else if (!src) { + /* This presumably is the source table. */ + src = tab_lock->table; + if (UT_LIST_GET_LEN(src->locks) != 1 || + UT_LIST_GET_FIRST(src->locks) != lock) { + /* We only support the case when + there is only one lock on this table. */ + return(NULL); + } + } else if (src != tab_lock->table) { + /* The transaction is locking more than + two tables (src and dest): abort */ + return(NULL); + } + + /* Check that the source table is locked by + LOCK_IX or LOCK_IS. */ + lock_mode = lock_get_mode(lock); + switch (lock_mode) { + case LOCK_IX: + case LOCK_IS: + if (*mode != LOCK_NONE && *mode != lock_mode) { + /* There are multiple locks on src. */ + return(NULL); + } + *mode = lock_mode; + break; + } + } + + if (!src) { + /* No source table lock found: flag the situation to caller */ + src = dest; + } + + return(src); +} + +/************************************************************************* +Determine if the given table is exclusively "owned" by the given +transaction, i.e., transaction holds LOCK_IX and possibly LOCK_AUTO_INC +on the table. */ + +ibool +lock_is_table_exclusive( +/*====================*/ + /* out: TRUE if table is only locked by trx, + with LOCK_IX, and possibly LOCK_AUTO_INC */ + dict_table_t* table, /* in: table */ + trx_t* trx) /* in: transaction */ +{ + lock_t* lock; + bool ok = FALSE; + + ut_ad(table && trx); + + for (lock = UT_LIST_GET_FIRST(table->locks); + lock; + lock = UT_LIST_GET_NEXT(locks, &lock->un_member.tab_lock)) { + if (lock->trx != trx) { + /* A lock on the table is held + by some other transaction. */ + return(FALSE); + } + + if (!(lock_get_type(lock) & LOCK_TABLE)) { + /* We are interested in table locks only. */ + continue; + } + + switch (lock_get_mode(lock)) { + case LOCK_IX: + ok = TRUE; + break; + case LOCK_AUTO_INC: + /* It is allowed for trx to hold an + auto_increment lock. */ + break; + default: + /* Other table locks than LOCK_IX are not allowed. */ + return(FALSE); + } + } + + return(ok); +} + /************************************************************************* Sets the wait flag of a lock and the back pointer in trx to lock. */ UNIV_INLINE diff --git a/innobase/row/row0mysql.c b/innobase/row/row0mysql.c index 9613da2e286460d19133bdd0091f0305b24e07d0..dec2b19559c205b5f809cd9a7d3b9f76950615a3 100644 --- a/innobase/row/row0mysql.c +++ b/innobase/row/row0mysql.c @@ -782,10 +782,11 @@ row_lock_table_for_mysql( /* out: error code or DB_SUCCESS */ row_prebuilt_t* prebuilt, /* in: prebuilt struct in the MySQL table handle */ - dict_table_t* table) /* in: table to LOCK_IX, or NULL + dict_table_t* table, /* in: table to lock, or NULL if prebuilt->table should be locked as LOCK_TABLE_EXP | prebuilt->select_lock_type */ + ulint mode) /* in: lock mode of table */ { trx_t* trx = prebuilt->trx; que_thr_t* thr; @@ -819,7 +820,7 @@ run_again: trx_start_if_not_started(trx); if (table) { - err = lock_table(0, table, LOCK_IX, thr); + err = lock_table(0, table, mode, thr); } else { err = lock_table(LOCK_TABLE_EXP, prebuilt->table, prebuilt->select_lock_type, thr); diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc index 2515b4956d07bc64b605f87259667e357475020a..cc69762cbdbc10a584049a021a1af6014c6da052 100644 --- a/sql/ha_innodb.cc +++ b/sql/ha_innodb.cc @@ -2324,20 +2324,58 @@ ha_innobase::write_row( position in the source table need not be adjusted after the intermediate COMMIT, since writes by other transactions are being blocked by a MySQL table lock TL_WRITE_ALLOW_READ. */ - ut_a(prebuilt->trx->mysql_n_tables_locked == 2); - ut_a(UT_LIST_GET_LEN(prebuilt->trx->trx_locks) >= 2); - dict_table_t* table = lock_get_ix_table( - UT_LIST_GET_FIRST(prebuilt->trx->trx_locks)); + + dict_table_t* src_table; + ibool mode; + num_write_row = 0; + /* Commit the transaction. This will release the table locks, so they have to be acquired again. */ - innobase_commit(user_thd, prebuilt->trx); - /* Note that this transaction is still active. */ - user_thd->transaction.all.innodb_active_trans = 1; - /* Re-acquire the IX table lock on the source table. */ - row_lock_table_for_mysql(prebuilt, table); - /* We will need an IX lock on the destination table. */ - prebuilt->sql_stat_start = TRUE; + + /* Altering an InnoDB table */ + /* Get the source table. */ + src_table = lock_get_src_table( + prebuilt->trx, prebuilt->table, &mode); + if (!src_table) { + no_commit: + /* Unknown situation: do not commit */ + /* + ut_print_timestamp(stderr); + fprintf(stderr, + " InnoDB error: ALTER TABLE is holding lock" + " on %lu tables!\n", + prebuilt->trx->mysql_n_tables_locked); + */ + ; + } else if (src_table == prebuilt->table) { + /* Source table is not in InnoDB format: + no need to re-acquire locks on it. */ + + /* Altering to InnoDB format */ + innobase_commit(user_thd, prebuilt->trx); + /* Note that this transaction is still active. */ + user_thd->transaction.all.innodb_active_trans = 1; + /* We will need an IX lock on the destination table. */ + prebuilt->sql_stat_start = TRUE; + } else { + /* Ensure that there are no other table locks than + LOCK_IX and LOCK_AUTO_INC on the destination table. */ + if (!lock_is_table_exclusive(prebuilt->table, + prebuilt->trx)) { + goto no_commit; + } + + /* Commit the transaction. This will release the table + locks, so they have to be acquired again. */ + innobase_commit(user_thd, prebuilt->trx); + /* Note that this transaction is still active. */ + user_thd->transaction.all.innodb_active_trans = 1; + /* Re-acquire the table lock on the source table. */ + row_lock_table_for_mysql(prebuilt, src_table, mode); + /* We will need an IX lock on the destination table. */ + prebuilt->sql_stat_start = TRUE; + } } num_write_row++; @@ -5015,7 +5053,8 @@ ha_innobase::external_lock( if (thd->in_lock_tables && thd->variables.innodb_table_locks) { ulint error; - error = row_lock_table_for_mysql(prebuilt, 0); + error = row_lock_table_for_mysql(prebuilt, + NULL, LOCK_TABLE_EXP); if (error != DB_SUCCESS) { error = convert_error_code_to_mysql(