Commit 86fcfb15 authored by Michael Widenius's avatar Michael Widenius

Fix for Bug#40311 Assert in MARIA_RECORD_POS during pushbuild 2 test:

Fixed bug when removing a newly inserted record (in case of duplicate key).
The bug caused a crash for rows with several blobs and the first blob was small enough to fit into the head page.
Don't change state_history if nothing changed (speed optimization that also simplifies logic).
Reset state_history if we added/deleted or updated rows without versioning.
Fixed wrong test in trnman_exists_active_transactions() if state is visible or not.

Other bugs fixed:
Fixed wrong argument to (lock->get_status) when we had to wait for TL_WRITE_CONCURRENT_INSERT.
Item_equal::update_used_tables() didn't calculate const_item_cache properly.
Added assert's to detect if join_read_const_table() was called under wrong assumptions..
Fixed that _ma_setup_live_state() is called from thr_lock() instead of handler::external_lock().
This was needed to get versioning information to be setup correctly.
Fixed error in debug binaries during a call to _ma_check_table_is_closed() when another thread was opening/closing a table.
Fixed wrong test when finding right history_state to use.

mysql-test/suite/maria/r/maria.result:
  Added test for Bug#40311 Assert in MARIA_RECORD_POS during pushbuild 2 test
mysql-test/suite/maria/t/maria.test:
  Added test for Bug#40311 Assert in MARIA_RECORD_POS during pushbuild 2 test
mysys/thr_lock.c:
  Fixed wrong argument to (lock->get_status) when we had to wait for TL_WRITE_CONCURRENT_INSERT
sql/item_cmpfunc.cc:
  Item_equal::update_used_tables() didn't calculate const_item_cache properly, which later caused a wrong result for item->const_item()
sql/sql_base.cc:
  In debug mode, Initilize record buffer with unexpected data to catch usage of uninitialized memory
sql/sql_select.cc:
  Fixed indentation
  Added assert's to detect if join_read_const_table() was called under wrong assumptions.
  One assert() is disabled for now as Item_equal() doesn't behave as expected.
storage/maria/ha_maria.cc:
  Move calling to _ma_setup_live_state() to ma_state.c::_ma_block_get_status()
  This was needed as _ma_setup_live_state() needed to know if the table will be used concurrently or not
storage/maria/ma_blockrec.c:
  Fixed bug when removing a newly inserted record (in case of duplicate key).
  The bug caused a crash for rows with several blobs and the first blob was small enough to fit into the head page.
storage/maria/ma_dbug.c:
  Added mutex to protect the open table list during _ma_check_table_is_closed().
  Without the protection we could get a error in debug binaries during a call to _ma_check_table_is_closed()
storage/maria/ma_delete_table.c:
  Removed not used code
storage/maria/ma_rename.c:
  Removed not used code
storage/maria/ma_state.c:
  Fixed wrong test when finding right history_state to use
  Mark in tables->state_current.no_transid if we are using transid's or not.
  Don't change state_history if nothing changed (speed optimization that also simplifies logic)
  Reset state_history if we added/deleted or updated rows without versioning.
  More DBUG_ASSERT's and more DBUG
  Updated maria_versioning() to initialize environment before calling _ma_blok_get_status(). This was needed because of the new logic in _ma_block_get_status()
storage/maria/ma_state.h:
  Added flags to detect if table changed and/or if we changed table without versioning
storage/maria/ma_write.c:
  Simple cleanups (No logic changes)
storage/maria/trnman.c:
  Fixed wrong test in trnman_exists_active_transactions() if state is visible or not.
parent 2b73d215
...@@ -2583,3 +2583,10 @@ lock table t1 read, t2 read; ...@@ -2583,3 +2583,10 @@ lock table t1 read, t2 read;
flush tables with read lock; flush tables with read lock;
unlock tables; unlock tables;
drop table t1, t2; drop table t1, t2;
create table t1(a int primary key, b blob, c blob) engine=maria;
insert into t1 values(1,repeat('a',100), repeat('b',657860));
Warnings:
Warning 1265 Data truncated for column 'c' at row 1
insert into t1 values(1,repeat('a',100), repeat('b',657860));
ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
drop table t1;
...@@ -1846,6 +1846,17 @@ flush tables with read lock; ...@@ -1846,6 +1846,17 @@ flush tables with read lock;
unlock tables; unlock tables;
drop table t1, t2; drop table t1, t2;
#
# Bug #40311
# Crash when aborting inserting of row with 2 blobs where first is short
#
create table t1(a int primary key, b blob, c blob) engine=maria;
insert into t1 values(1,repeat('a',100), repeat('b',657860));
--error ER_DUP_ENTRY
insert into t1 values(1,repeat('a',100), repeat('b',657860));
drop table t1;
# Set defaults back # Set defaults back
--disable_result_log --disable_result_log
--disable_query_log --disable_query_log
......
...@@ -494,7 +494,8 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data, ...@@ -494,7 +494,8 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
{ {
result= THR_LOCK_SUCCESS; result= THR_LOCK_SUCCESS;
if (data->lock->get_status) if (data->lock->get_status)
(*data->lock->get_status)(data->status_param, 0); (*data->lock->get_status)(data->status_param,
data->type == TL_WRITE_CONCURRENT_INSERT);
check_locks(data->lock,"got wait_for_lock",0); check_locks(data->lock,"got wait_for_lock",0);
} }
pthread_mutex_unlock(&data->lock->mutex); pthread_mutex_unlock(&data->lock->mutex);
......
...@@ -5234,6 +5234,7 @@ void Item_equal::update_used_tables() ...@@ -5234,6 +5234,7 @@ void Item_equal::update_used_tables()
not_null_tables_cache= used_tables_cache= 0; not_null_tables_cache= used_tables_cache= 0;
if ((const_item_cache= cond_false)) if ((const_item_cache= cond_false))
return; return;
const_item_cache= 1;
while ((item=li++)) while ((item=li++))
{ {
item->update_used_tables(); item->update_used_tables();
......
...@@ -2979,6 +2979,13 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root, ...@@ -2979,6 +2979,13 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
table->pos_in_table_list= table_list; table->pos_in_table_list= table_list;
table_list->updatable= 1; // It is not derived table nor non-updatable VIEW table_list->updatable= 1; // It is not derived table nor non-updatable VIEW
table->clear_column_bitmaps(); table->clear_column_bitmaps();
#if !defined(DBUG_OFF) && !defined(HAVE_purify)
/*
Fill record with random values to find bugs where we access fields
without first reading them.
*/
bfill(table->record[0], table->reclength, 254);
#endif
DBUG_ASSERT(table->key_read == 0); DBUG_ASSERT(table->key_read == 0);
DBUG_RETURN(table); DBUG_RETURN(table);
} }
......
...@@ -2517,8 +2517,7 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables, COND *conds, ...@@ -2517,8 +2517,7 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables, COND *conds,
s->needed_reg.init(); s->needed_reg.init();
table_vector[i]=s->table=table=tables->table; table_vector[i]=s->table=table=tables->table;
table->pos_in_table_list= tables; table->pos_in_table_list= tables;
error= table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK); if ((error= table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK)))
if(error)
{ {
table->file->print_error(error, MYF(0)); table->file->print_error(error, MYF(0));
DBUG_RETURN(1); DBUG_RETURN(1);
...@@ -11609,6 +11608,11 @@ join_read_const_table(JOIN_TAB *tab, POSITION *pos) ...@@ -11609,6 +11608,11 @@ join_read_const_table(JOIN_TAB *tab, POSITION *pos)
if (!table->maybe_null || error > 0) if (!table->maybe_null || error > 0)
DBUG_RETURN(error); DBUG_RETURN(error);
} }
/*
The optimizer trust the engine that when stats.records is 0, there
was no found rows
*/
DBUG_ASSERT(table->file->stats.records > 0 || error);
} }
else else
{ {
...@@ -11638,6 +11642,17 @@ join_read_const_table(JOIN_TAB *tab, POSITION *pos) ...@@ -11638,6 +11642,17 @@ join_read_const_table(JOIN_TAB *tab, POSITION *pos)
} }
if (*tab->on_expr_ref && !table->null_row) if (*tab->on_expr_ref && !table->null_row)
{ {
#if !defined(DBUG_OFF) && defined(NOT_USING_ITEM_EQUAL)
/*
This test could be very usefull to find bugs in the optimizer
where we would call this function with an expression that can't be
evaluated yet. We can't have this enabled by default as long as
have items like Item_equal, that doesn't report they are const but
they can still be called even if they contain not const items.
*/
(*tab->on_expr_ref)->update_used_tables();
DBUG_ASSERT((*tab->on_expr_ref)->const_item());
#endif
if ((table->null_row= test((*tab->on_expr_ref)->val_int() == 0))) if ((table->null_row= test((*tab->on_expr_ref)->val_int() == 0)))
mark_as_null_row(table); mark_as_null_row(table);
} }
......
...@@ -2319,13 +2319,7 @@ int ha_maria::external_lock(THD *thd, int lock_type) ...@@ -2319,13 +2319,7 @@ int ha_maria::external_lock(THD *thd, int lock_type)
trnman_new_statement(trn); trnman_new_statement(trn);
} }
/* If handler uses versioning */ if (!file->s->lock_key_trees) // If we don't use versioning
if (file->s->lock_key_trees)
{
if (_ma_setup_live_state(file))
DBUG_RETURN(HA_ERR_OUT_OF_MEM);
}
else
{ {
/* /*
We come here in the following cases: We come here in the following cases:
......
...@@ -3488,6 +3488,8 @@ my_bool _ma_write_abort_block_record(MARIA_HA *info) ...@@ -3488,6 +3488,8 @@ my_bool _ma_write_abort_block_record(MARIA_HA *info)
res= 1; res= 1;
for (block= blocks->block + 1, end= block + blocks->count - 1; block < end; for (block= blocks->block + 1, end= block + blocks->count - 1; block < end;
block++) block++)
{
if (block->used & BLOCKUSED_USED)
{ {
if (block->used & BLOCKUSED_TAIL) if (block->used & BLOCKUSED_TAIL)
{ {
...@@ -3495,17 +3497,18 @@ my_bool _ma_write_abort_block_record(MARIA_HA *info) ...@@ -3495,17 +3497,18 @@ my_bool _ma_write_abort_block_record(MARIA_HA *info)
block->page_count is set to the tail directory entry number in block->page_count is set to the tail directory entry number in
write_block_record() write_block_record()
*/ */
if (delete_head_or_tail(info, block->page, block->page_count & ~TAIL_BIT, if (delete_head_or_tail(info, block->page,
block->page_count & ~TAIL_BIT,
0, 0)) 0, 0))
res= 1; res= 1;
} }
else if (block->used & BLOCKUSED_USED) else
{ {
if (free_full_page_range(info, block->page, block->page_count)) if (free_full_page_range(info, block->page, block->page_count))
res= 1; res= 1;
} }
} }
}
if (share->now_transactional) if (share->now_transactional)
{ {
if (_ma_write_clr(info, info->cur_row.orig_undo_lsn, if (_ma_write_clr(info, info->cur_row.orig_undo_lsn,
......
...@@ -180,6 +180,7 @@ my_bool _ma_check_table_is_closed(const char *name, const char *where) ...@@ -180,6 +180,7 @@ my_bool _ma_check_table_is_closed(const char *name, const char *where)
DBUG_ENTER("_ma_check_table_is_closed"); DBUG_ENTER("_ma_check_table_is_closed");
(void) fn_format(filename,name,"",MARIA_NAME_IEXT,4+16+32); (void) fn_format(filename,name,"",MARIA_NAME_IEXT,4+16+32);
pthread_mutex_lock(&THR_LOCK_maria);
for (pos=maria_open_list ; pos ; pos=pos->next) for (pos=maria_open_list ; pos ; pos=pos->next)
{ {
MARIA_HA *info=(MARIA_HA*) pos->data; MARIA_HA *info=(MARIA_HA*) pos->data;
...@@ -190,10 +191,12 @@ my_bool _ma_check_table_is_closed(const char *name, const char *where) ...@@ -190,10 +191,12 @@ my_bool _ma_check_table_is_closed(const char *name, const char *where)
{ {
fprintf(stderr,"Warning: Table: %s is open on %s\n", name,where); fprintf(stderr,"Warning: Table: %s is open on %s\n", name,where);
DBUG_PRINT("warning",("Table: %s is open on %s", name,where)); DBUG_PRINT("warning",("Table: %s is open on %s", name,where));
pthread_mutex_unlock(&THR_LOCK_maria);
DBUG_RETURN(1); DBUG_RETURN(1);
} }
} }
} }
pthread_mutex_unlock(&THR_LOCK_maria);
DBUG_RETURN(0); DBUG_RETURN(0);
} }
#endif /* EXTRA_DEBUG */ #endif /* EXTRA_DEBUG */
...@@ -69,11 +69,6 @@ int maria_delete_table(const char *name) ...@@ -69,11 +69,6 @@ int maria_delete_table(const char *name)
MY_SYNC_DIR : 0; MY_SYNC_DIR : 0;
maria_close(info); maria_close(info);
} }
#ifdef USE_RAID
#ifdef EXTRA_DEBUG
_ma_check_table_is_closed(name,"delete");
#endif
#endif /* USE_RAID */
if (sync_dir) if (sync_dir)
{ {
......
...@@ -104,11 +104,6 @@ int maria_rename(const char *old_name, const char *new_name) ...@@ -104,11 +104,6 @@ int maria_rename(const char *old_name, const char *new_name)
} }
maria_close(info); maria_close(info);
#ifdef USE_RAID
#ifdef EXTRA_DEBUG
_ma_check_table_is_closed(old_name,"rename raidcheck");
#endif
#endif /* USE_RAID */
fn_format(from,old_name,"",MARIA_NAME_IEXT,MY_UNPACK_FILENAME|MY_APPEND_EXT); fn_format(from,old_name,"",MARIA_NAME_IEXT,MY_UNPACK_FILENAME|MY_APPEND_EXT);
fn_format(to,new_name,"",MARIA_NAME_IEXT,MY_UNPACK_FILENAME|MY_APPEND_EXT); fn_format(to,new_name,"",MARIA_NAME_IEXT,MY_UNPACK_FILENAME|MY_APPEND_EXT);
......
...@@ -91,18 +91,26 @@ my_bool _ma_setup_live_state(MARIA_HA *info) ...@@ -91,18 +91,26 @@ my_bool _ma_setup_live_state(MARIA_HA *info)
It's enough to compare trids here (instead of calling It's enough to compare trids here (instead of calling
tranman_can_read_from) as history->trid is a commit_trid tranman_can_read_from) as history->trid is a commit_trid
*/ */
while (trn->trid < history->trid && history->trid != ~(TrID)0) while (trn->trid <= history->trid)
history= history->next; history= history->next;
pthread_mutex_unlock(&share->intern_lock); pthread_mutex_unlock(&share->intern_lock);
/* The current item can't be deleted as it's the first one visible for us */ /* The current item can't be deleted as it's the first one visible for us */
tables->state_start= tables->state_current= history->state; tables->state_start= tables->state_current= history->state;
tables->state_current.changed= 0; tables->state_current.changed= tables->state_current.no_transid= 0;
DBUG_PRINT("info", ("records: %ld", (ulong) tables->state_start.records)); DBUG_PRINT("info", ("records: %ld", (ulong) tables->state_start.records));
end: end:
info->state_start= &tables->state_start; info->state_start= &tables->state_start;
info->state= &tables->state_current; info->state= &tables->state_current;
/*
Mark in transaction state if we are not using transid (versioning)
on rows. If not, then we will in _ma_trnman_end_trans_hook()
ensure that the state is visible for all at end of transaction
*/
tables->state_current.no_transid|= !(info->row_flag & ROW_FLAG_TRANSID);
DBUG_RETURN(0); DBUG_RETURN(0);
} }
...@@ -406,6 +414,22 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit, ...@@ -406,6 +414,22 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit,
MARIA_STATE_HISTORY *history; MARIA_STATE_HISTORY *history;
pthread_mutex_lock(&share->intern_lock); pthread_mutex_lock(&share->intern_lock);
/* We only have to update history state if something changed */
if (tables->state_current.changed)
{
if (tables->state_current.no_transid)
{
/*
The change was done without using transid on rows (like in
bulk insert). In this case this thread is the only one
that is using the table and all rows will be visble
for all transactions.
*/
_ma_reset_history(share);
}
else
{
if (active_transactions && share->now_transactional && if (active_transactions && share->now_transactional &&
trnman_exists_active_transactions(share->state_history->trid, trnman_exists_active_transactions(share->state_history->trid,
trn->commit_trid, 1)) trn->commit_trid, 1))
...@@ -435,7 +459,8 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit, ...@@ -435,7 +459,8 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit,
/* Previous history can't be seen by anyone, reuse old memory */ /* Previous history can't be seen by anyone, reuse old memory */
history= share->state_history; history= share->state_history;
DBUG_PRINT("info", ("removing history->trid: %lu new: %lu", DBUG_PRINT("info", ("removing history->trid: %lu new: %lu",
(ulong) history->trid, (ulong) trn->commit_trid)); (ulong) history->trid,
(ulong) trn->commit_trid));
} }
history->state.records+= (tables->state_current.records - history->state.records+= (tables->state_current.records -
...@@ -451,6 +476,8 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit, ...@@ -451,6 +476,8 @@ my_bool _ma_trnman_end_trans_hook(TRN *trn, my_bool commit,
} }
DBUG_PRINT("info", ("share: 0x%lx in_trans: %d", DBUG_PRINT("info", ("share: 0x%lx in_trans: %d",
(ulong) share, share->in_trans)); (ulong) share, share->in_trans));
}
}
share->in_trans--; share->in_trans--;
pthread_mutex_unlock(&share->intern_lock); pthread_mutex_unlock(&share->intern_lock);
} }
...@@ -511,7 +538,6 @@ void _ma_remove_table_from_trnman(MARIA_SHARE *share, TRN *trn) ...@@ -511,7 +538,6 @@ void _ma_remove_table_from_trnman(MARIA_SHARE *share, TRN *trn)
/**************************************************************************** /****************************************************************************
The following functions are called by thr_lock() in threaded applications The following functions are called by thr_lock() in threaded applications
for transactional tables. for transactional tables.
...@@ -536,9 +562,24 @@ void _ma_block_get_status(void* param, my_bool concurrent_insert) ...@@ -536,9 +562,24 @@ void _ma_block_get_status(void* param, my_bool concurrent_insert)
info->row_flag= info->s->base.default_row_flag; info->row_flag= info->s->base.default_row_flag;
if (concurrent_insert) if (concurrent_insert)
{ {
DBUG_ASSERT(info->lock.type == TL_WRITE_CONCURRENT_INSERT);
info->row_flag|= ROW_FLAG_TRANSID; info->row_flag|= ROW_FLAG_TRANSID;
info->row_base_length+= TRANSID_SIZE; info->row_base_length+= TRANSID_SIZE;
} }
else
{
DBUG_ASSERT(info->lock.type != TL_WRITE_CONCURRENT_INSERT);
}
if (info->s->lock_key_trees)
{
/*
Assume for now that this doesn't fail (It can only fail in
out of memory conditions)
TODO: Fix this by having one extra state pre-allocated
*/
(void) _ma_setup_live_state(info);
}
DBUG_VOID_RETURN; DBUG_VOID_RETURN;
} }
...@@ -574,7 +615,12 @@ void maria_versioning(MARIA_HA *info, my_bool versioning) ...@@ -574,7 +615,12 @@ void maria_versioning(MARIA_HA *info, my_bool versioning)
{ {
/* For now, this is a hack */ /* For now, this is a hack */
if (info->s->have_versioning) if (info->s->have_versioning)
{
/* Assume is a non threaded application (for now) */
info->s->lock_key_trees= 0;
info->lock.type= versioning ? TL_WRITE_CONCURRENT_INSERT : TL_WRITE;
_ma_block_get_status((void*) info, versioning); _ma_block_get_status((void*) info, versioning);
}
} }
...@@ -609,6 +655,7 @@ void _ma_copy_nontrans_state_information(MARIA_HA *info) ...@@ -609,6 +655,7 @@ void _ma_copy_nontrans_state_information(MARIA_HA *info)
void _ma_reset_history(MARIA_SHARE *share) void _ma_reset_history(MARIA_SHARE *share)
{ {
MARIA_STATE_HISTORY *history, *next; MARIA_STATE_HISTORY *history, *next;
DBUG_ENTER("_ma_reset_history");
share->state_history->trid= 0; /* Visibly by all */ share->state_history->trid= 0; /* Visibly by all */
share->state_history->state= share->state.state; share->state_history->state= share->state.state;
...@@ -620,6 +667,7 @@ void _ma_reset_history(MARIA_SHARE *share) ...@@ -620,6 +667,7 @@ void _ma_reset_history(MARIA_SHARE *share)
next= history->next; next= history->next;
my_free(history, MYF(0)); my_free(history, MYF(0));
} }
DBUG_VOID_RETURN;
} }
......
...@@ -24,7 +24,8 @@ typedef struct st_maria_status_info ...@@ -24,7 +24,8 @@ typedef struct st_maria_status_info
my_off_t key_file_length; my_off_t key_file_length;
my_off_t data_file_length; my_off_t data_file_length;
ha_checksum checksum; ha_checksum checksum;
my_bool changed; uint32 changed:1, /* Set if table was changed */
no_transid:1; /* Set if no transid was set on rows */
} MARIA_STATUS_INFO; } MARIA_STATUS_INFO;
......
...@@ -230,9 +230,11 @@ int maria_write(MARIA_HA *info, uchar *record) ...@@ -230,9 +230,11 @@ int maria_write(MARIA_HA *info, uchar *record)
/* running. now we wait */ /* running. now we wait */
WT_RESOURCE_ID rc; WT_RESOURCE_ID rc;
int res; int res;
const char *old_proc_info;
rc.type= &ma_rc_dup_unique; rc.type= &ma_rc_dup_unique;
rc.value= (intptr)blocker; /* TODO savepoint id when we'll have them */ /* TODO savepoint id when we'll have them */
rc.value= (intptr)blocker;
res= wt_thd_will_wait_for(info->trn->wt, blocker->wt, & rc); res= wt_thd_will_wait_for(info->trn->wt, blocker->wt, & rc);
if (res != WT_OK) if (res != WT_OK)
{ {
...@@ -240,14 +242,12 @@ int maria_write(MARIA_HA *info, uchar *record) ...@@ -240,14 +242,12 @@ int maria_write(MARIA_HA *info, uchar *record)
my_errno= HA_ERR_LOCK_DEADLOCK; my_errno= HA_ERR_LOCK_DEADLOCK;
goto err; goto err;
} }
{ old_proc_info= proc_info_hook(0,
const char *old_proc_info= proc_info_hook(0, "waiting for a resource",
"waiting for a resource", __func__, __FILE__, __LINE__); __func__, __FILE__, __LINE__);
res= wt_thd_cond_timedwait(info->trn->wt, & blocker->state_lock); res= wt_thd_cond_timedwait(info->trn->wt, & blocker->state_lock);
proc_info_hook(0, old_proc_info, __func__, __FILE__, __LINE__); proc_info_hook(0, old_proc_info, __func__, __FILE__, __LINE__);
}
pthread_mutex_unlock(& blocker->state_lock); pthread_mutex_unlock(& blocker->state_lock);
if (res != WT_OK) if (res != WT_OK)
{ {
......
...@@ -885,11 +885,22 @@ my_bool trnman_exists_active_transactions(TrID min_id, TrID max_id, ...@@ -885,11 +885,22 @@ my_bool trnman_exists_active_transactions(TrID min_id, TrID max_id,
for (trn= active_list_min.next; trn != &active_list_max; trn= trn->next) for (trn= active_list_min.next; trn != &active_list_max; trn= trn->next)
{ {
/* /*
We use >= for min_id as min_id is a commit_trid and trn->trid We use <= for max_id as max_id is a commit_trid and trn->trid
is transaction id. In the case they are the same, then the is transaction id. When calculating commit_trid we use the
trn started after the min_id was committed. current value of global_trid_generator. global_trid_generator is
incremented for each new transaction.
For example, assuming we have
min_id = 5
max_id = 10
A trid of value 5 can't see the history event between 5 & 10
at it vas started before min_id 5 was committed.
A trid of value 10 can't see the next history event (max_id = 10)
as it started before this was committed. In this case it must use
the this event.
*/ */
if (trn->trid >= min_id && trn->trid < max_id) if (trn->trid > min_id && trn->trid <= max_id)
{ {
ret= 1; ret= 1;
break; break;
......
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