diff options
Diffstat (limited to 'storage/myisam/mi_locking.c')
| -rw-r--r-- | storage/myisam/mi_locking.c | 666 |
1 files changed, 666 insertions, 0 deletions
diff --git a/storage/myisam/mi_locking.c b/storage/myisam/mi_locking.c new file mode 100644 index 00000000..67b25376 --- /dev/null +++ b/storage/myisam/mi_locking.c @@ -0,0 +1,666 @@ +/* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. + Copyright (c) 2009, 2018, MariaDB Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* + locking of isam-tables. + reads info from a isam-table. Must be first request before doing any furter + calls to any isamfunktion. Is used to allow many process use the same + isamdatabase. +*/ + +#include "ftdefs.h" + +static void mi_update_status_with_lock(MI_INFO *info); + + /* lock table by F_UNLCK, F_RDLCK or F_WRLCK */ + +int mi_lock_database(MI_INFO *info, int lock_type) +{ + int error, mark_crashed= 0; + uint count; + MYISAM_SHARE *share=info->s; + DBUG_ENTER("mi_lock_database"); + DBUG_PRINT("enter",("lock_type: %d old lock %d r_locks: %u w_locks: %u " + "global_changed: %d open_count: %u name: '%s'", + lock_type, info->lock_type, share->r_locks, + share->w_locks, + share->global_changed, share->state.open_count, + share->index_file_name)); + if (share->options & HA_OPTION_READ_ONLY_DATA || + info->lock_type == lock_type) + DBUG_RETURN(0); + if (lock_type == F_EXTRA_LCK) /* Used by TMP tables */ + { + ++share->w_locks; + ++share->tot_locks; + info->lock_type= lock_type; + info->s->in_use= list_add(info->s->in_use, &info->in_use); + DBUG_RETURN(0); + } + + error= 0; + DBUG_EXECUTE_IF ("mi_lock_database_failure", error= EINVAL;); + if (!info->intern_lock_locked) + mysql_mutex_lock(&share->intern_lock); + if (share->kfile >= 0) /* May only be false on windows */ + { + switch (lock_type) { + case F_UNLCK: + ftparser_call_deinitializer(info); + if (info->lock_type == F_RDLCK) + { + count= --share->r_locks; + mi_restore_status(info); + } + else + { + count= --share->w_locks; + mi_update_status_with_lock(info); + } + --share->tot_locks; + if (info->lock_type == F_WRLCK && !share->w_locks && + !share->delay_key_write && flush_key_blocks(share->key_cache, + share->kfile, + &share->dirty_part_map, + FLUSH_KEEP)) + { + mark_crashed= error=my_errno; + mi_print_error(info->s, HA_ERR_CRASHED); + } + if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED)) + { + if (end_io_cache(&info->rec_cache)) + { + mark_crashed= error=my_errno; + mi_print_error(info->s, HA_ERR_CRASHED); + } + } + if (!count) + { + DBUG_PRINT("info",("changed: %u w_locks: %u", + (uint) share->changed, share->w_locks)); + if (share->changed && !share->w_locks) + { +#ifdef HAVE_MMAP + if ((info->s->mmaped_length != info->s->state.state.data_file_length) && + (info->s->nonmmaped_inserts > MAX_NONMAPPED_INSERTS)) + { + if (info->s->concurrent_insert) + mysql_rwlock_wrlock(&info->s->mmap_lock); + mi_remap_file(info, info->s->state.state.data_file_length); + info->s->nonmmaped_inserts= 0; + if (info->s->concurrent_insert) + mysql_rwlock_unlock(&info->s->mmap_lock); + } +#endif + share->state.process= share->last_process=share->this_process; + share->state.unique= info->last_unique= info->this_unique; + share->state.update_count= info->last_loop= ++info->this_loop; + if (mi_state_info_write(share->kfile, &share->state, 1)) + mark_crashed= error=my_errno; + share->changed=0; + if (myisam_flush) + { + if (share->file_map) + my_msync(info->dfile, share->file_map, share->mmaped_length, MS_SYNC); + if (mysql_file_sync(share->kfile, MYF(0))) + mark_crashed= error= my_errno; + if (mysql_file_sync(info->dfile, MYF(0))) + mark_crashed= error= my_errno; + } + else + share->not_flushed=1; + if (error) + mi_print_error(info->s, HA_ERR_CRASHED); + } + if (info->lock_type != F_EXTRA_LCK) + { + if (share->r_locks) + { /* Only read locks left */ + if (my_lock(share->kfile,F_RDLCK,0L,F_TO_EOF, + MYF(MY_WME | MY_SEEK_NOT_DONE)) && !error) + error=my_errno; + } + else if (!share->w_locks) + { /* No more locks */ + if (my_lock(share->kfile,F_UNLCK,0L,F_TO_EOF, + MYF(MY_WME | MY_SEEK_NOT_DONE)) && !error) + error=my_errno; + } + } + } + info->opt_flag&= ~(READ_CACHE_USED | WRITE_CACHE_USED); + info->lock_type= F_UNLCK; + info->s->in_use= list_delete(info->s->in_use, &info->in_use); + break; + case F_RDLCK: + if (info->lock_type == F_WRLCK) + { + /* + Change RW to READONLY + + mysqld does not turn write locks to read locks, + so we're never here in mysqld. + */ + if (share->w_locks == 1) + { + if (my_lock(share->kfile,lock_type,0L,F_TO_EOF, + MYF(MY_SEEK_NOT_DONE))) + { + error=my_errno; + break; + } + } + share->w_locks--; + share->r_locks++; + info->lock_type=lock_type; + break; + } + if (!share->r_locks && !share->w_locks) + { + if (my_lock(share->kfile,lock_type,0L,F_TO_EOF, + info->lock_wait | MY_SEEK_NOT_DONE)) + { + error=my_errno; + break; + } + if (mi_state_info_read_dsk(share->kfile, &share->state, 1)) + { + error=my_errno; + (void) my_lock(share->kfile,F_UNLCK,0L,F_TO_EOF,MYF(MY_SEEK_NOT_DONE)); + my_errno=error; + break; + } + } + (void) _mi_test_if_changed(info); + share->r_locks++; + share->tot_locks++; + info->lock_type=lock_type; + info->s->in_use= list_add(info->s->in_use, &info->in_use); + break; + case F_WRLCK: + if (info->lock_type == F_RDLCK) + { /* Change READONLY to RW */ + if (share->r_locks == 1) + { + if (my_lock(share->kfile,lock_type,0L,F_TO_EOF, + MYF(info->lock_wait | MY_SEEK_NOT_DONE))) + { + error=my_errno; + break; + } + share->r_locks--; + share->w_locks++; + info->lock_type=lock_type; + break; + } + } + if (!(share->options & HA_OPTION_READ_ONLY_DATA)) + { + if (!share->w_locks) + { + if (my_lock(share->kfile,lock_type,0L,F_TO_EOF, + info->lock_wait | MY_SEEK_NOT_DONE)) + { + error=my_errno; + break; + } + if (!share->r_locks) + { + if (mi_state_info_read_dsk(share->kfile, &share->state, 1)) + { + error=my_errno; + (void) my_lock(share->kfile,F_UNLCK,0L,F_TO_EOF, + info->lock_wait | MY_SEEK_NOT_DONE); + my_errno=error; + break; + } + } + } + } + (void) _mi_test_if_changed(info); + + info->lock_type=lock_type; + info->invalidator=info->s->invalidator; + share->w_locks++; + share->tot_locks++; + + DBUG_EXECUTE_IF("simulate_incorrect_share_wlock_value", + DEBUG_SYNC_C("after_share_wlock_increment");); + + info->s->in_use= list_add(info->s->in_use, &info->in_use); + break; + default: + break; /* Impossible */ + } + } +#ifdef _WIN32 + else + { + /* + Check for bad file descriptors if this table is part + of a merge union. Failing to capture this may cause + a crash on windows if the table is renamed and + later on referenced by the merge table. + */ + if ((info->open_flag & HA_OPEN_MERGE_TABLE) && (info->s)->kfile < 0) + { + error = HA_ERR_NO_SUCH_TABLE; + } + } +#endif + if (!info->intern_lock_locked) + mysql_mutex_unlock(&share->intern_lock); + if (mark_crashed) + mi_mark_crashed(info); + DBUG_RETURN(error); +} /* mi_lock_database */ + + +/**************************************************************************** + The following functions are called by thr_lock() in threaded applications +****************************************************************************/ + +/* + Create a copy of the current status for the table + + SYNOPSIS + mi_get_status() + param Pointer to Myisam handler + concurrent_insert Set to 1 if we are going to do concurrent inserts + (THR_WRITE_CONCURRENT_INSERT was used) +*/ + +my_bool mi_get_status(void* param, my_bool concurrent_insert) +{ + MI_INFO *info=(MI_INFO*) param; + DBUG_ENTER("mi_get_status"); + DBUG_PRINT("info",("name: %s key_file: %lu data_file: %lu rows: %lu concurrent_insert: %d", + info->s->index_file_name, + (ulong) info->s->state.state.key_file_length, + (ulong) info->s->state.state.data_file_length, + (ulong) info->s->state.state.records, + concurrent_insert)); +#ifndef DBUG_OFF + if (info->state->key_file_length > info->s->state.state.key_file_length || + info->state->data_file_length > info->s->state.state.data_file_length) + DBUG_PRINT("warning",("old info: key_file: %ld data_file: %ld", + (long) info->state->key_file_length, + (long) info->state->data_file_length)); +#endif + info->save_state=info->s->state.state; + info->state= &info->save_state; + info->append_insert_at_end= concurrent_insert; + if (concurrent_insert) + info->s->state.state.uncacheable= TRUE; + DBUG_RETURN(0); +} + + +void mi_update_status(void* param) +{ + MI_INFO *info=(MI_INFO*) param; + DBUG_ENTER("mi_update_status"); + /* + Because someone may have closed the table we point at, we only + update the state if its our own state. This isn't a problem as + we are always pointing at our own lock or at a read lock. + (This is enforced by thr_multi_lock.c) + */ + if (info->state == &info->save_state) + { + DBUG_PRINT("info", + ("updating status: key_file: %lu data_file: %lu rows: %lu", + (ulong) info->state->key_file_length, + (ulong) info->state->data_file_length, + (ulong) info->state->records)); + if (info->state->key_file_length < info->s->state.state.key_file_length || + info->state->data_file_length < info->s->state.state.data_file_length) + DBUG_PRINT("warning",("old info: key_file: %ld data_file: %ld", + (long) info->s->state.state.key_file_length, + (long) info->s->state.state.data_file_length)); + info->s->state.state= *info->state; +#ifdef HAVE_QUERY_CACHE + DBUG_PRINT("info", ("invalidator... '%s' (status update)", + info->filename)); + DBUG_ASSERT(info->s->chst_invalidator != NULL); + (*info->s->chst_invalidator)((const char *)info->filename); +#endif + } + + info->state= &info->s->state.state; + info->append_insert_at_end= 0; + + /* + We have to flush the write cache here as other threads may start + reading the table before mi_lock_database() is called + */ + if (info->opt_flag & WRITE_CACHE_USED) + { + if (end_io_cache(&info->rec_cache)) + { + mi_print_error(info->s, HA_ERR_CRASHED); + mi_mark_crashed(info); + } + info->opt_flag&= ~WRITE_CACHE_USED; + } + DBUG_VOID_RETURN; +} + +/* + Same as mi_update_status() but take a lock in the table lock, to protect + against someone calling mi_get_status() from thr_lock() at the same time. +*/ + +static void mi_update_status_with_lock(MI_INFO *info) +{ + my_bool locked= 0; + if (info->state == &info->save_state) + { + locked= 1; + mysql_mutex_lock(&info->s->lock.mutex); + } + mi_update_status(info); + if (locked) + mysql_mutex_unlock(&info->s->lock.mutex); +} + + +void mi_restore_status(void *param) +{ + MI_INFO *info= (MI_INFO*) param; + DBUG_ENTER("mi_restore_status"); + DBUG_PRINT("info",("key_file: %ld data_file: %ld", + (long) info->s->state.state.key_file_length, + (long) info->s->state.state.data_file_length)); + info->state= &info->s->state.state; + info->append_insert_at_end= 0; + DBUG_VOID_RETURN; +} + + +void mi_copy_status(void* to,void *from) +{ + MI_INFO *info= (MI_INFO*) to; + DBUG_ENTER("mi_copy_status"); + info->state= &((MI_INFO*) from)->save_state; + DBUG_PRINT("info",("key_file: %ld data_file: %ld", + (long) info->state->key_file_length, + (long) info->state->data_file_length)); + DBUG_VOID_RETURN; +} + + +/* + Check if should allow concurrent inserts + + IMPLEMENTATION + Allow concurrent inserts if we don't have a hole in the table or + if there is no active write lock and there is active read locks and + myisam_concurrent_insert == 2. In this last case the new + row('s) are inserted at end of file instead of filling up the hole. + + The last case is to allow one to inserts into a heavily read-used table + even if there is holes. + + NOTES + If there is a an rtree indexes in the table, concurrent inserts are + disabled in mi_open() + + RETURN + 0 ok to use concurrent inserts + 1 not ok +*/ + +my_bool mi_check_status(void *param) +{ + MI_INFO *info=(MI_INFO*) param; + DBUG_ENTER("mi_check_status"); + DBUG_PRINT("info",("dellink: %ld r_locks: %u w_locks: %u", + (long) info->s->state.dellink, (uint) info->s->r_locks, + (uint) info->s->w_locks)); + /* + The test for w_locks == 1 is here because this thread has already done an + external lock (in other words: w_locks == 1 means no other threads has + a write lock) + */ + DBUG_RETURN((my_bool) !(info->s->state.dellink == HA_OFFSET_ERROR || + (myisam_concurrent_insert == 2 && info->s->r_locks && + info->s->w_locks == 1))); +} + + +/** + Fix status for thr_lock_merge() + + @param org_table + @param new_table that should point on org_lock. new_table is 0 + in case this is the first occurrence of the table in the lock + structure. +*/ + +void mi_fix_status(MI_INFO *org_table, MI_INFO *new_table) +{ + DBUG_ENTER("mi_fix_status"); + if (!new_table) + { + /* First in group. Set state as in mi_get_status() */ + org_table->state= &org_table->save_state; + } + else + { + /* Set new_table to use state from org_table (first lock of this table) */ + new_table->state= org_table->state; + } + DBUG_VOID_RETURN; +} + + +/**************************************************************************** + ** functions to read / write the state +****************************************************************************/ + +int _mi_readinfo(register MI_INFO *info, int lock_type, int check_keybuffer) +{ + DBUG_ENTER("_mi_readinfo"); + + if (info->lock_type == F_UNLCK) + { + MYISAM_SHARE *share=info->s; + if (!share->tot_locks) + { + if (my_lock(share->kfile,lock_type,0L,F_TO_EOF, + info->lock_wait | MY_SEEK_NOT_DONE)) + DBUG_RETURN(1); + if (mi_state_info_read_dsk(share->kfile, &share->state, 1)) + { + int error= my_errno ? my_errno : HA_ERR_FILE_TOO_SHORT; + (void) my_lock(share->kfile,F_UNLCK,0L,F_TO_EOF, + MYF(MY_SEEK_NOT_DONE)); + my_errno= error; + DBUG_RETURN(1); + } + } + if (check_keybuffer) + (void) _mi_test_if_changed(info); + info->invalidator=info->s->invalidator; + } + else if (lock_type == F_WRLCK && info->lock_type == F_RDLCK) + { + my_errno=EACCES; /* Not allowed to change */ + DBUG_RETURN(-1); /* when have read_lock() */ + } + DBUG_RETURN(0); +} /* _mi_readinfo */ + + +/* + Every isam-function that uppdates the isam-database MUST end with this + request +*/ + +int _mi_writeinfo(register MI_INFO *info, uint operation) +{ + int error,olderror; + MYISAM_SHARE *share=info->s; + DBUG_ENTER("_mi_writeinfo"); + DBUG_PRINT("info",("operation: %u tot_locks: %u", operation, + share->tot_locks)); + + error=0; + if (share->tot_locks == 0) + { + olderror=my_errno; /* Remember last error */ + if (operation) + { /* Two threads can't be here */ + share->state.process= share->last_process= share->this_process; + share->state.unique= info->last_unique= info->this_unique; + share->state.update_count= info->last_loop= ++info->this_loop; + if ((error=mi_state_info_write(share->kfile, &share->state, 1))) + olderror=my_errno; +#ifdef _WIN32 + if (myisam_flush) + { + if (share->file_map) + my_msync(info->dfile, share->file_map, share->mmaped_length, MS_SYNC); + mysql_file_sync(share->kfile, 0); + mysql_file_sync(info->dfile, 0); + } +#endif + } + if (!(operation & WRITEINFO_NO_UNLOCK) && + my_lock(share->kfile,F_UNLCK,0L,F_TO_EOF, + MYF(MY_WME | MY_SEEK_NOT_DONE)) && !error) + DBUG_RETURN(1); + my_errno=olderror; + } + else if (operation) + share->changed= 1; /* Mark keyfile changed */ + DBUG_RETURN(error); +} /* _mi_writeinfo */ + + + /* Test if someone has changed the database */ + /* (Should be called after readinfo) */ + +int _mi_test_if_changed(register MI_INFO *info) +{ + MYISAM_SHARE *share=info->s; + if (share->state.process != share->last_process || + share->state.unique != info->last_unique || + share->state.update_count != info->last_loop) + { /* Keyfile has changed */ + DBUG_PRINT("info",("index file changed")); + if (share->state.process != share->this_process) + (void) flush_key_blocks(share->key_cache, share->kfile, + &share->dirty_part_map, FLUSH_RELEASE); + share->last_process=share->state.process; + info->last_unique= share->state.unique; + info->last_loop= share->state.update_count; + info->update|= HA_STATE_WRITTEN; /* Must use file on next */ + info->data_changed= 1; /* For mi_is_changed */ + return 1; + } + return (!(info->update & HA_STATE_AKTIV) || + (info->update & (HA_STATE_WRITTEN | HA_STATE_DELETED | + HA_STATE_KEY_CHANGED))); +} /* _mi_test_if_changed */ + + +/* + Put a mark in the .MYI file that someone is updating the table + + + DOCUMENTATION + + state.open_count in the .MYI file is used the following way: + - For the first change of the .MYI file in this process open_count is + incremented by mi_mark_file_change(). (We have a write lock on the file + when this happens) + - In mi_close() it's decremented by _mi_decrement_open_count() if it + was incremented in the same process. + + This mean that if we are the only process using the file, the open_count + tells us if the MYISAM file wasn't properly closed. (This is true if + my_disable_locking is set). +*/ + + +int _mi_mark_file_changed(MI_INFO *info) +{ + uchar buff[3]; + register MYISAM_SHARE *share=info->s; + DBUG_ENTER("_mi_mark_file_changed"); + + if (!(share->state.changed & STATE_CHANGED) || ! share->global_changed) + { + share->state.changed|=(STATE_CHANGED | STATE_NOT_ANALYZED | + STATE_NOT_OPTIMIZED_KEYS); + if (!share->global_changed) + { + share->global_changed=1; + share->state.open_count++; + } + if (!share->temporary) + { + mi_int2store(buff,share->state.open_count); + buff[2]=1; /* Mark that it's changed */ + DBUG_RETURN((int)mysql_file_pwrite(share->kfile, buff, sizeof(buff), + sizeof(share->state.header), + MYF(MY_NABP))); + } + } + DBUG_RETURN(0); +} + + +/* + This is only called by close or by extra(HA_FLUSH) if the OS has the pwrite() + call. In these context the following code should be safe! + */ + +int _mi_decrement_open_count(MI_INFO *info) +{ + uchar buff[2]; + register MYISAM_SHARE *share=info->s; + int lock_error=0,write_error=0; + if (share->global_changed) + { + uint old_lock=info->lock_type; + share->global_changed=0; + lock_error= my_disable_locking ? 0 : mi_lock_database(info,F_WRLCK); + /* Its not fatal even if we couldn't get the lock ! */ + if (share->state.open_count > 0) + { + share->state.open_count--; + mi_int2store(buff,share->state.open_count); + write_error= (mysql_file_pwrite(share->kfile, buff, sizeof(buff), + sizeof(share->state.header), + MYF(MY_NABP)) != 0); + } + if (!lock_error && !my_disable_locking) + lock_error=mi_lock_database(info,old_lock); + } + return MY_TEST(lock_error || write_error); +} + + +void _mi_report_crashed_ignore(MI_INFO *file __attribute__((unused)), + const char *message __attribute__((unused)), + const char *sfile __attribute__((unused)), + uint sline __attribute__((unused))) +{ +} |