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/*****************************************************************************
Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2009, Google Inc.
Portions of this file contain modifications contributed and copyrighted by
Google, Inc. Those modifications are gratefully acknowledged and are described
briefly in the InnoDB documentation. The contributions by Google are
incorporated with their permission, and subject to the conditions contained in
the file COPYING.Google.
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 Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file log/log0log.cc
Database log
Created 12/9/1995 Heikki Tuuri
*******************************************************/
#include "ha_prototypes.h"
#include <debug_sync.h>
#include "log0log.h"
#ifdef UNIV_NONINL
#include "log0log.ic"
#endif
#include "mem0mem.h"
#include "buf0buf.h"
#ifndef UNIV_HOTBACKUP
#include "buf0flu.h"
#include "srv0srv.h"
#include "log0recv.h"
#include "fil0fil.h"
#include "dict0boot.h"
#include "dict0stats_bg.h"
#include "srv0srv.h"
#include "srv0start.h"
#include "trx0sys.h"
#include "trx0trx.h"
#include "trx0roll.h"
#include "srv0mon.h"
#include "sync0sync.h"
#endif /* !UNIV_HOTBACKUP */
/*
General philosophy of InnoDB redo-logs:
1) Every change to a contents of a data page must be done
through mtr, which in mtr_commit() writes log records
to the InnoDB redo log.
2) Normally these changes are performed using a mlog_write_ulint()
or similar function.
3) In some page level operations only a code number of a
c-function and its parameters are written to the log to
reduce the size of the log.
3a) You should not add parameters to these kind of functions
(e.g. trx_undo_header_create(), trx_undo_insert_header_reuse())
3b) You should not add such functionality which either change
working when compared with the old or are dependent on data
outside of the page. These kind of functions should implement
self-contained page transformation and it should be unchanged
if you don't have very essential reasons to change log
semantics or format.
*/
/** Redo log system */
log_t* log_sys = NULL;
/** Whether to generate and require checksums on the redo log pages */
my_bool innodb_log_checksums;
/** Pointer to the log checksum calculation function */
log_checksum_func_t log_checksum_algorithm_ptr;
/* These control how often we print warnings if the last checkpoint is too
old */
bool log_has_printed_chkp_warning = false;
time_t log_last_warning_time;
bool log_has_printed_chkp_margine_warning = false;
time_t log_last_margine_warning_time;
/* A margin for free space in the log buffer before a log entry is catenated */
#define LOG_BUF_WRITE_MARGIN (4 * OS_FILE_LOG_BLOCK_SIZE)
/* Margins for free space in the log buffer after a log entry is catenated */
#define LOG_BUF_FLUSH_RATIO 2
#define LOG_BUF_FLUSH_MARGIN (LOG_BUF_WRITE_MARGIN + 4 * UNIV_PAGE_SIZE)
/* This parameter controls asynchronous making of a new checkpoint; the value
should be bigger than LOG_POOL_PREFLUSH_RATIO_SYNC */
#define LOG_POOL_CHECKPOINT_RATIO_ASYNC 32
/* This parameter controls synchronous preflushing of modified buffer pages */
#define LOG_POOL_PREFLUSH_RATIO_SYNC 16
/* The same ratio for asynchronous preflushing; this value should be less than
the previous */
#define LOG_POOL_PREFLUSH_RATIO_ASYNC 8
/* Codes used in unlocking flush latches */
#define LOG_UNLOCK_NONE_FLUSHED_LOCK 1
#define LOG_UNLOCK_FLUSH_LOCK 2
/******************************************************//**
Completes a checkpoint write i/o to a log file. */
static
void
log_io_complete_checkpoint(void);
/*============================*/
#ifndef UNIV_HOTBACKUP
/****************************************************************//**
Returns the oldest modified block lsn in the pool, or log_sys->lsn if none
exists.
@return LSN of oldest modification */
static
lsn_t
log_buf_pool_get_oldest_modification(void)
/*======================================*/
{
lsn_t lsn;
ut_ad(log_mutex_own());
lsn = buf_pool_get_oldest_modification();
if (!lsn) {
lsn = log_sys->lsn;
}
return(lsn);
}
#endif /* !UNIV_HOTBACKUP */
/** Extends the log buffer.
@param[in] len requested minimum size in bytes */
void
log_buffer_extend(
ulint len)
{
ulint move_start;
ulint move_end;
byte tmp_buf[OS_FILE_LOG_BLOCK_SIZE];
log_mutex_enter_all();
while (log_sys->is_extending) {
/* Another thread is trying to extend already.
Needs to wait for. */
log_mutex_exit_all();
log_buffer_flush_to_disk();
log_mutex_enter_all();
if (srv_log_buffer_size > len / UNIV_PAGE_SIZE) {
/* Already extended enough by the others */
log_mutex_exit_all();
return;
}
}
if (len >= log_sys->buf_size / 2) {
DBUG_EXECUTE_IF("ib_log_buffer_is_short_crash",
DBUG_SUICIDE(););
/* log_buffer is too small. try to extend instead of crash. */
ib::warn() << "The transaction log size is too large"
" for innodb_log_buffer_size (" << len << " >= "
<< LOG_BUFFER_SIZE << " / 2). Trying to extend it.";
}
log_sys->is_extending = true;
while (ut_calc_align_down(log_sys->buf_free,
OS_FILE_LOG_BLOCK_SIZE)
!= ut_calc_align_down(log_sys->buf_next_to_write,
OS_FILE_LOG_BLOCK_SIZE)) {
/* Buffer might have >1 blocks to write still. */
log_mutex_exit_all();
log_buffer_flush_to_disk();
log_mutex_enter_all();
}
move_start = ut_calc_align_down(
log_sys->buf_free,
OS_FILE_LOG_BLOCK_SIZE);
move_end = log_sys->buf_free;
/* store the last log block in buffer */
ut_memcpy(tmp_buf, log_sys->buf + move_start,
move_end - move_start);
log_sys->buf_free -= move_start;
log_sys->buf_next_to_write -= move_start;
/* reallocate log buffer */
srv_log_buffer_size = len / UNIV_PAGE_SIZE + 1;
ut_free(log_sys->buf_ptr);
log_sys->buf_size = LOG_BUFFER_SIZE;
log_sys->buf_ptr = static_cast<byte*>(
ut_zalloc_nokey(log_sys->buf_size * 2 + OS_FILE_LOG_BLOCK_SIZE));
log_sys->buf = static_cast<byte*>(
ut_align(log_sys->buf_ptr, OS_FILE_LOG_BLOCK_SIZE));
log_sys->first_in_use = true;
log_sys->max_buf_free = log_sys->buf_size / LOG_BUF_FLUSH_RATIO
- LOG_BUF_FLUSH_MARGIN;
/* restore the last log block */
ut_memcpy(log_sys->buf, tmp_buf, move_end - move_start);
ut_ad(log_sys->is_extending);
log_sys->is_extending = false;
log_mutex_exit_all();
ib::info() << "innodb_log_buffer_size was extended to "
<< LOG_BUFFER_SIZE << ".";
}
#ifndef UNIV_HOTBACKUP
/** Calculate actual length in redo buffer and file including
block header and trailer.
@param[in] len length to write
@return actual length to write including header and trailer. */
static inline
ulint
log_calculate_actual_len(
ulint len)
{
ut_ad(log_mutex_own());
/* actual length stored per block */
const ulint len_per_blk = OS_FILE_LOG_BLOCK_SIZE
- (LOG_BLOCK_HDR_SIZE + LOG_BLOCK_TRL_SIZE);
/* actual data length in last block already written */
ulint extra_len = (log_sys->buf_free % OS_FILE_LOG_BLOCK_SIZE);
ut_ad(extra_len >= LOG_BLOCK_HDR_SIZE);
extra_len -= LOG_BLOCK_HDR_SIZE;
/* total extra length for block header and trailer */
extra_len = ((len + extra_len) / len_per_blk)
* (LOG_BLOCK_HDR_SIZE + LOG_BLOCK_TRL_SIZE);
return(len + extra_len);
}
/** Check margin not to overwrite transaction log from the last checkpoint.
If would estimate the log write to exceed the log_group_capacity,
waits for the checkpoint is done enough.
@param[in] len length of the data to be written */
void
log_margin_checkpoint_age(
ulint len)
{
ulint margin = log_calculate_actual_len(len);
ut_ad(log_mutex_own());
if (margin > log_sys->log_group_capacity) {
/* return with warning output to avoid deadlock */
if (!log_has_printed_chkp_margine_warning
|| difftime(time(NULL),
log_last_margine_warning_time) > 15) {
log_has_printed_chkp_margine_warning = true;
log_last_margine_warning_time = time(NULL);
ib::error() << "The transaction log files are too"
" small for the single transaction log (size="
<< len << "). So, the last checkpoint age"
" might exceed the log group capacity "
<< log_sys->log_group_capacity << ".";
}
return;
}
/* Our margin check should ensure that we never reach this condition.
Try to do checkpoint once. We cannot keep waiting here as it might
result in hang in case the current mtr has latch on oldest lsn */
if (log_sys->lsn - log_sys->last_checkpoint_lsn + margin
> log_sys->log_group_capacity) {
/* The log write of 'len' might overwrite the transaction log
after the last checkpoint. Makes checkpoint. */
bool flushed_enough = false;
if (log_sys->lsn - log_buf_pool_get_oldest_modification()
+ margin
<= log_sys->log_group_capacity) {
flushed_enough = true;
}
log_sys->check_flush_or_checkpoint = true;
log_mutex_exit();
DEBUG_SYNC_C("margin_checkpoint_age_rescue");
if (!flushed_enough) {
os_thread_sleep(100000);
}
log_checkpoint(true, false);
log_mutex_enter();
}
return;
}
#endif /* !UNIV_HOTBACKUP */
/** Open the log for log_write_low. The log must be closed with log_close.
@param[in] len length of the data to be written
@return start lsn of the log record */
lsn_t
log_reserve_and_open(
ulint len)
{
ulint len_upper_limit;
#ifdef UNIV_DEBUG
ulint count = 0;
#endif /* UNIV_DEBUG */
loop:
ut_ad(log_mutex_own());
ut_ad(!recv_no_log_write);
if (log_sys->is_extending) {
log_mutex_exit();
/* Log buffer size is extending. Writing up to the next block
should wait for the extending finished. */
os_thread_sleep(100000);
ut_ad(++count < 50);
log_mutex_enter();
goto loop;
}
/* Calculate an upper limit for the space the string may take in the
log buffer */
len_upper_limit = LOG_BUF_WRITE_MARGIN + srv_log_write_ahead_size
+ (5 * len) / 4;
if (log_sys->buf_free + len_upper_limit > log_sys->buf_size) {
log_mutex_exit();
DEBUG_SYNC_C("log_buf_size_exceeded");
/* Not enough free space, do a write of the log buffer */
log_buffer_sync_in_background(false);
srv_stats.log_waits.inc();
ut_ad(++count < 50);
log_mutex_enter();
goto loop;
}
return(log_sys->lsn);
}
/************************************************************//**
Writes to the log the string given. It is assumed that the caller holds the
log mutex. */
void
log_write_low(
/*==========*/
const byte* str, /*!< in: string */
ulint str_len) /*!< in: string length */
{
log_t* log = log_sys;
ulint len;
ulint data_len;
byte* log_block;
ut_ad(log_mutex_own());
part_loop:
ut_ad(!recv_no_log_write);
/* Calculate a part length */
data_len = (log->buf_free % OS_FILE_LOG_BLOCK_SIZE) + str_len;
if (data_len <= OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE) {
/* The string fits within the current log block */
len = str_len;
} else {
data_len = OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE;
len = OS_FILE_LOG_BLOCK_SIZE
- (log->buf_free % OS_FILE_LOG_BLOCK_SIZE)
- LOG_BLOCK_TRL_SIZE;
}
ut_memcpy(log->buf + log->buf_free, str, len);
str_len -= len;
str = str + len;
log_block = static_cast<byte*>(
ut_align_down(
log->buf + log->buf_free, OS_FILE_LOG_BLOCK_SIZE));
log_block_set_data_len(log_block, data_len);
if (data_len == OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE) {
/* This block became full */
log_block_set_data_len(log_block, OS_FILE_LOG_BLOCK_SIZE);
log_block_set_checkpoint_no(log_block,
log_sys->next_checkpoint_no);
len += LOG_BLOCK_HDR_SIZE + LOG_BLOCK_TRL_SIZE;
log->lsn += len;
/* Initialize the next block header */
log_block_init(log_block + OS_FILE_LOG_BLOCK_SIZE, log->lsn);
} else {
log->lsn += len;
}
log->buf_free += len;
ut_ad(log->buf_free <= log->buf_size);
if (str_len > 0) {
goto part_loop;
}
srv_stats.log_write_requests.inc();
}
/************************************************************//**
Closes the log.
@return lsn */
lsn_t
log_close(void)
/*===========*/
{
byte* log_block;
ulint first_rec_group;
lsn_t oldest_lsn;
lsn_t lsn;
log_t* log = log_sys;
lsn_t checkpoint_age;
ut_ad(log_mutex_own());
ut_ad(!recv_no_log_write);
lsn = log->lsn;
log_block = static_cast<byte*>(
ut_align_down(
log->buf + log->buf_free, OS_FILE_LOG_BLOCK_SIZE));
first_rec_group = log_block_get_first_rec_group(log_block);
if (first_rec_group == 0) {
/* We initialized a new log block which was not written
full by the current mtr: the next mtr log record group
will start within this block at the offset data_len */
log_block_set_first_rec_group(
log_block, log_block_get_data_len(log_block));
}
if (log->buf_free > log->max_buf_free) {
log->check_flush_or_checkpoint = true;
}
checkpoint_age = lsn - log->last_checkpoint_lsn;
if (checkpoint_age >= log->log_group_capacity) {
DBUG_EXECUTE_IF(
"print_all_chkp_warnings",
log_has_printed_chkp_warning = false;);
if (!log_has_printed_chkp_warning
|| difftime(time(NULL), log_last_warning_time) > 15) {
log_has_printed_chkp_warning = true;
log_last_warning_time = time(NULL);
ib::error() << "The age of the last checkpoint is "
<< checkpoint_age << ", which exceeds the log"
" group capacity " << log->log_group_capacity
<< ".";
}
}
if (checkpoint_age <= log->max_modified_age_sync) {
goto function_exit;
}
oldest_lsn = buf_pool_get_oldest_modification();
if (!oldest_lsn
|| lsn - oldest_lsn > log->max_modified_age_sync
|| checkpoint_age > log->max_checkpoint_age_async) {
log->check_flush_or_checkpoint = true;
}
function_exit:
return(lsn);
}
/******************************************************//**
Calculates the data capacity of a log group, when the log file headers are not
included.
@return capacity in bytes */
lsn_t
log_group_get_capacity(
/*===================*/
const log_group_t* group) /*!< in: log group */
{
/* The lsn parameters are updated while holding both the mutexes
and it is ok to have either of them while reading */
ut_ad(log_mutex_own() || log_write_mutex_own());
return((group->file_size - LOG_FILE_HDR_SIZE) * group->n_files);
}
/******************************************************//**
Calculates the offset within a log group, when the log file headers are not
included.
@return size offset (<= offset) */
UNIV_INLINE
lsn_t
log_group_calc_size_offset(
/*=======================*/
lsn_t offset, /*!< in: real offset within the
log group */
const log_group_t* group) /*!< in: log group */
{
/* The lsn parameters are updated while holding both the mutexes
and it is ok to have either of them while reading */
ut_ad(log_mutex_own() || log_write_mutex_own());
return(offset - LOG_FILE_HDR_SIZE * (1 + offset / group->file_size));
}
/******************************************************//**
Calculates the offset within a log group, when the log file headers are
included.
@return real offset (>= offset) */
UNIV_INLINE
lsn_t
log_group_calc_real_offset(
/*=======================*/
lsn_t offset, /*!< in: size offset within the
log group */
const log_group_t* group) /*!< in: log group */
{
/* The lsn parameters are updated while holding both the mutexes
and it is ok to have either of them while reading */
ut_ad(log_mutex_own() || log_write_mutex_own());
return(offset + LOG_FILE_HDR_SIZE
* (1 + offset / (group->file_size - LOG_FILE_HDR_SIZE)));
}
/** Calculate the offset of an lsn within a log group.
@param[in] lsn log sequence number
@param[in] group log group
@return offset within the log group */
lsn_t
log_group_calc_lsn_offset(
lsn_t lsn,
const log_group_t* group)
{
lsn_t gr_lsn;
lsn_t gr_lsn_size_offset;
lsn_t difference;
lsn_t group_size;
lsn_t offset;
/* The lsn parameters are updated while holding both the mutexes
and it is ok to have either of them while reading */
ut_ad(log_mutex_own() || log_write_mutex_own());
gr_lsn = group->lsn;
gr_lsn_size_offset = log_group_calc_size_offset(
group->lsn_offset, group);
group_size = log_group_get_capacity(group);
if (lsn >= gr_lsn) {
difference = lsn - gr_lsn;
} else {
difference = gr_lsn - lsn;
difference = difference % group_size;
difference = group_size - difference;
}
offset = (gr_lsn_size_offset + difference) % group_size;
/* fprintf(stderr,
"Offset is " LSN_PF " gr_lsn_offset is " LSN_PF
" difference is " LSN_PF "\n",
offset, gr_lsn_size_offset, difference);
*/
return(log_group_calc_real_offset(offset, group));
}
/*******************************************************************//**
Calculates where in log files we find a specified lsn.
@return log file number */
ulint
log_calc_where_lsn_is(
/*==================*/
int64_t* log_file_offset, /*!< out: offset in that file
(including the header) */
ib_uint64_t first_header_lsn, /*!< in: first log file start
lsn */
ib_uint64_t lsn, /*!< in: lsn whose position to
determine */
ulint n_log_files, /*!< in: total number of log
files */
int64_t log_file_size) /*!< in: log file size
(including the header) */
{
int64_t capacity = log_file_size - LOG_FILE_HDR_SIZE;
ulint file_no;
int64_t add_this_many;
if (lsn < first_header_lsn) {
add_this_many = 1 + (first_header_lsn - lsn)
/ (capacity * static_cast<int64_t>(n_log_files));
lsn += add_this_many
* capacity * static_cast<int64_t>(n_log_files);
}
ut_a(lsn >= first_header_lsn);
file_no = ((ulint)((lsn - first_header_lsn) / capacity))
% n_log_files;
*log_file_offset = (lsn - first_header_lsn) % capacity;
*log_file_offset = *log_file_offset + LOG_FILE_HDR_SIZE;
return(file_no);
}
/********************************************************//**
Sets the field values in group to correspond to a given lsn. For this function
to work, the values must already be correctly initialized to correspond to
some lsn, for instance, a checkpoint lsn. */
void
log_group_set_fields(
/*=================*/
log_group_t* group, /*!< in/out: group */
lsn_t lsn) /*!< in: lsn for which the values should be
set */
{
group->lsn_offset = log_group_calc_lsn_offset(lsn, group);
group->lsn = lsn;
}
#ifndef UNIV_HOTBACKUP
/*****************************************************************//**
Calculates the recommended highest values for lsn - last_checkpoint_lsn
and lsn - buf_get_oldest_modification().
@retval true on success
@retval false if the smallest log group is too small to
accommodate the number of OS threads in the database server */
static MY_ATTRIBUTE((warn_unused_result))
bool
log_calc_max_ages(void)
/*===================*/
{
log_group_t* group;
lsn_t margin;
ulint free;
bool success = true;
lsn_t smallest_capacity;
log_mutex_enter();
group = UT_LIST_GET_FIRST(log_sys->log_groups);
ut_ad(group);
smallest_capacity = LSN_MAX;
while (group) {
if (log_group_get_capacity(group) < smallest_capacity) {
smallest_capacity = log_group_get_capacity(group);
}
group = UT_LIST_GET_NEXT(log_groups, group);
}
/* Add extra safety */
smallest_capacity = smallest_capacity - smallest_capacity / 10;
/* For each OS thread we must reserve so much free space in the
smallest log group that it can accommodate the log entries produced
by single query steps: running out of free log space is a serious
system error which requires rebooting the database. */
free = LOG_CHECKPOINT_FREE_PER_THREAD * (10 + srv_thread_concurrency)
+ LOG_CHECKPOINT_EXTRA_FREE;
if (free >= smallest_capacity / 2) {
success = false;
goto failure;
} else {
margin = smallest_capacity - free;
}
margin = margin - margin / 10; /* Add still some extra safety */
log_sys->log_group_capacity = smallest_capacity;
log_sys->max_modified_age_async = margin
- margin / LOG_POOL_PREFLUSH_RATIO_ASYNC;
log_sys->max_modified_age_sync = margin
- margin / LOG_POOL_PREFLUSH_RATIO_SYNC;
log_sys->max_checkpoint_age_async = margin - margin
/ LOG_POOL_CHECKPOINT_RATIO_ASYNC;
log_sys->max_checkpoint_age = margin;
failure:
log_mutex_exit();
if (!success) {
ib::error() << "Cannot continue operation. ib_logfiles are too"
" small for innodb_thread_concurrency "
<< srv_thread_concurrency << ". The combined size of"
" ib_logfiles should be bigger than"
" 200 kB * innodb_thread_concurrency. To get mysqld"
" to start up, set innodb_thread_concurrency in"
" my.cnf to a lower value, for example, to 8. After"
" an ERROR-FREE shutdown of mysqld you can adjust"
" the size of ib_logfiles. " << INNODB_PARAMETERS_MSG;
}
return(success);
}
/******************************************************//**
Initializes the log. */
void
log_init(void)
/*==========*/
{
log_sys = static_cast<log_t*>(ut_zalloc_nokey(sizeof(log_t)));
mutex_create(LATCH_ID_LOG_SYS, &log_sys->mutex);
mutex_create(LATCH_ID_LOG_WRITE, &log_sys->write_mutex);
mutex_create(LATCH_ID_LOG_FLUSH_ORDER, &log_sys->log_flush_order_mutex);
/* Start the lsn from one log block from zero: this way every
log record has a start lsn != zero, a fact which we will use */
log_sys->lsn = LOG_START_LSN;
ut_a(LOG_BUFFER_SIZE >= 16 * OS_FILE_LOG_BLOCK_SIZE);
ut_a(LOG_BUFFER_SIZE >= 4 * UNIV_PAGE_SIZE);
log_sys->buf_size = LOG_BUFFER_SIZE;
log_sys->buf_ptr = static_cast<byte*>(
ut_zalloc_nokey(log_sys->buf_size * 2 + OS_FILE_LOG_BLOCK_SIZE));
log_sys->buf = static_cast<byte*>(
ut_align(log_sys->buf_ptr, OS_FILE_LOG_BLOCK_SIZE));
log_sys->first_in_use = true;
log_sys->max_buf_free = log_sys->buf_size / LOG_BUF_FLUSH_RATIO
- LOG_BUF_FLUSH_MARGIN;
log_sys->check_flush_or_checkpoint = true;
UT_LIST_INIT(log_sys->log_groups, &log_group_t::log_groups);
log_sys->n_log_ios_old = log_sys->n_log_ios;
log_sys->last_printout_time = time(NULL);
/*----------------------------*/
log_sys->write_lsn = log_sys->lsn;
log_sys->flush_event = os_event_create(0);
os_event_set(log_sys->flush_event);
/*----------------------------*/
log_sys->last_checkpoint_lsn = log_sys->lsn;
rw_lock_create(
checkpoint_lock_key, &log_sys->checkpoint_lock,
SYNC_NO_ORDER_CHECK);
log_sys->checkpoint_buf_ptr = static_cast<byte*>(
ut_zalloc_nokey(2 * OS_FILE_LOG_BLOCK_SIZE));
log_sys->checkpoint_buf = static_cast<byte*>(
ut_align(log_sys->checkpoint_buf_ptr, OS_FILE_LOG_BLOCK_SIZE));
/*----------------------------*/
log_block_init(log_sys->buf, log_sys->lsn);
log_block_set_first_rec_group(log_sys->buf, LOG_BLOCK_HDR_SIZE);
log_sys->buf_free = LOG_BLOCK_HDR_SIZE;
log_sys->lsn = LOG_START_LSN + LOG_BLOCK_HDR_SIZE;
MONITOR_SET(MONITOR_LSN_CHECKPOINT_AGE,
log_sys->lsn - log_sys->last_checkpoint_lsn);
}
/******************************************************************//**
Inits a log group to the log system.
@return true if success, false if not */
MY_ATTRIBUTE((warn_unused_result))
bool
log_group_init(
/*===========*/
ulint id, /*!< in: group id */
ulint n_files, /*!< in: number of log files */
lsn_t file_size, /*!< in: log file size in bytes */
ulint space_id) /*!< in: space id of the file space
which contains the log files of this
group */
{
ulint i;
log_group_t* group;
group = static_cast<log_group_t*>(ut_malloc_nokey(sizeof(log_group_t)));
group->id = id;
group->n_files = n_files;
group->format = LOG_HEADER_FORMAT_CURRENT;
group->file_size = file_size;
group->space_id = space_id;
group->state = LOG_GROUP_OK;
group->lsn = LOG_START_LSN;
group->lsn_offset = LOG_FILE_HDR_SIZE;
group->file_header_bufs_ptr = static_cast<byte**>(
ut_zalloc_nokey(sizeof(byte*) * n_files));
group->file_header_bufs = static_cast<byte**>(
ut_zalloc_nokey(sizeof(byte**) * n_files));
for (i = 0; i < n_files; i++) {
group->file_header_bufs_ptr[i] = static_cast<byte*>(
ut_zalloc_nokey(LOG_FILE_HDR_SIZE
+ OS_FILE_LOG_BLOCK_SIZE));
group->file_header_bufs[i] = static_cast<byte*>(
ut_align(group->file_header_bufs_ptr[i],
OS_FILE_LOG_BLOCK_SIZE));
}
group->checkpoint_buf_ptr = static_cast<byte*>(
ut_zalloc_nokey(2 * OS_FILE_LOG_BLOCK_SIZE));
group->checkpoint_buf = static_cast<byte*>(
ut_align(group->checkpoint_buf_ptr,OS_FILE_LOG_BLOCK_SIZE));
UT_LIST_ADD_LAST(log_sys->log_groups, group);
return(log_calc_max_ages());
}
#endif /* !UNIV_HOTBACKUP */
/******************************************************//**
Completes an i/o to a log file. */
void
log_io_complete(
/*============*/
log_group_t* group) /*!< in: log group or a dummy pointer */
{
if ((ulint) group & 0x1UL) {
/* It was a checkpoint write */
group = (log_group_t*)((ulint) group - 1);
#ifdef _WIN32
fil_flush(group->space_id);
#else
switch (srv_unix_file_flush_method) {
case SRV_UNIX_O_DSYNC:
case SRV_UNIX_NOSYNC:
break;
case SRV_UNIX_FSYNC:
case SRV_UNIX_LITTLESYNC:
case SRV_UNIX_O_DIRECT:
case SRV_UNIX_O_DIRECT_NO_FSYNC:
fil_flush(group->space_id);
}
#endif /* _WIN32 */
DBUG_PRINT("ib_log", ("checkpoint info written to group %u",
unsigned(group->id)));
log_io_complete_checkpoint();
return;
}
ut_error; /*!< We currently use synchronous writing of the
logs and cannot end up here! */
}
/******************************************************//**
Writes a log file header to a log file space. */
static
void
log_group_file_header_flush(
/*========================*/
log_group_t* group, /*!< in: log group */
ulint nth_file, /*!< in: header to the nth file in the
log file space */
lsn_t start_lsn) /*!< in: log file data starts at this
lsn */
{
byte* buf;
lsn_t dest_offset;
ut_ad(log_write_mutex_own());
ut_ad(!recv_no_log_write);
ut_ad(group->id == 0);
ut_a(nth_file < group->n_files);
buf = *(group->file_header_bufs + nth_file);
memset(buf, 0, OS_FILE_LOG_BLOCK_SIZE);
mach_write_to_4(buf + LOG_HEADER_FORMAT, LOG_HEADER_FORMAT_CURRENT);
mach_write_to_8(buf + LOG_HEADER_START_LSN, start_lsn);
strcpy(reinterpret_cast<char*>(buf) + LOG_HEADER_CREATOR,
LOG_HEADER_CREATOR_CURRENT);
ut_ad(LOG_HEADER_CREATOR_END - LOG_HEADER_CREATOR
>= sizeof LOG_HEADER_CREATOR_CURRENT);
log_block_set_checksum(buf, log_block_calc_checksum_crc32(buf));
dest_offset = nth_file * group->file_size;
DBUG_PRINT("ib_log", ("write " LSN_PF
" group " ULINTPF
" file " ULINTPF " header",
start_lsn, group->id, nth_file));
log_sys->n_log_ios++;
MONITOR_INC(MONITOR_LOG_IO);
srv_stats.os_log_pending_writes.inc();
const ulint page_no
= (ulint) (dest_offset / univ_page_size.physical());
fil_io(IORequestLogWrite, true,
page_id_t(group->space_id, page_no),
univ_page_size,
(ulint) (dest_offset % univ_page_size.physical()),
OS_FILE_LOG_BLOCK_SIZE, buf, group);
srv_stats.os_log_pending_writes.dec();
}
/******************************************************//**
Stores a 4-byte checksum to the trailer checksum field of a log block
before writing it to a log file. This checksum is used in recovery to
check the consistency of a log block. */
static
void
log_block_store_checksum(
/*=====================*/
byte* block) /*!< in/out: pointer to a log block */
{
log_block_set_checksum(block, log_block_calc_checksum(block));
}
/******************************************************//**
Writes a buffer to a log file group. */
static
void
log_group_write_buf(
/*================*/
log_group_t* group, /*!< in: log group */
byte* buf, /*!< in: buffer */
ulint len, /*!< in: buffer len; must be divisible
by OS_FILE_LOG_BLOCK_SIZE */
#ifdef UNIV_DEBUG
ulint pad_len, /*!< in: pad len in the buffer len */
#endif /* UNIV_DEBUG */
lsn_t start_lsn, /*!< in: start lsn of the buffer; must
be divisible by
OS_FILE_LOG_BLOCK_SIZE */
ulint new_data_offset)/*!< in: start offset of new data in
buf: this parameter is used to decide
if we have to write a new log file
header */
{
ulint write_len;
bool write_header = new_data_offset == 0;
lsn_t next_offset;
ulint i;
ut_ad(log_write_mutex_own());
ut_ad(!recv_no_log_write);
ut_a(len % OS_FILE_LOG_BLOCK_SIZE == 0);
ut_a(start_lsn % OS_FILE_LOG_BLOCK_SIZE == 0);
loop:
if (len == 0) {
return;
}
next_offset = log_group_calc_lsn_offset(start_lsn, group);
if (write_header
&& next_offset % group->file_size == LOG_FILE_HDR_SIZE) {
/* We start to write a new log file instance in the group */
ut_a(next_offset / group->file_size <= ULINT_MAX);
log_group_file_header_flush(group, (ulint)
(next_offset / group->file_size),
start_lsn);
srv_stats.os_log_written.add(OS_FILE_LOG_BLOCK_SIZE);
srv_stats.log_writes.inc();
}
if ((next_offset % group->file_size) + len > group->file_size) {
/* if the above condition holds, then the below expression
is < len which is ulint, so the typecast is ok */
write_len = (ulint)
(group->file_size - (next_offset % group->file_size));
} else {
write_len = len;
}
DBUG_PRINT("ib_log",
("write " LSN_PF " to " LSN_PF
": group " ULINTPF " len " ULINTPF
" blocks " ULINTPF ".." ULINTPF,
start_lsn, next_offset,
group->id, write_len,
log_block_get_hdr_no(buf),
log_block_get_hdr_no(
buf + write_len
- OS_FILE_LOG_BLOCK_SIZE)));
ut_ad(pad_len >= len
|| log_block_get_hdr_no(buf)
== log_block_convert_lsn_to_no(start_lsn));
/* Calculate the checksums for each log block and write them to
the trailer fields of the log blocks */
for (i = 0; i < write_len / OS_FILE_LOG_BLOCK_SIZE; i++) {
ut_ad(pad_len >= len
|| i * OS_FILE_LOG_BLOCK_SIZE >= len - pad_len
|| log_block_get_hdr_no(
buf + i * OS_FILE_LOG_BLOCK_SIZE)
== log_block_get_hdr_no(buf) + i);
log_block_store_checksum(buf + i * OS_FILE_LOG_BLOCK_SIZE);
}
log_sys->n_log_ios++;
MONITOR_INC(MONITOR_LOG_IO);
srv_stats.os_log_pending_writes.inc();
ut_a(next_offset / UNIV_PAGE_SIZE <= ULINT_MAX);
const ulint page_no
= (ulint) (next_offset / univ_page_size.physical());
fil_io(IORequestLogWrite, true,
page_id_t(group->space_id, page_no),
univ_page_size,
(ulint) (next_offset % UNIV_PAGE_SIZE), write_len, buf,
group);
srv_stats.os_log_pending_writes.dec();
srv_stats.os_log_written.add(write_len);
srv_stats.log_writes.inc();
if (write_len < len) {
start_lsn += write_len;
len -= write_len;
buf += write_len;
write_header = true;
goto loop;
}
}
/** Flush the log has been written to the log file. */
static
void
log_write_flush_to_disk_low()
{
ut_a(log_sys->n_pending_flushes == 1); /* No other threads here */
#ifndef _WIN32
bool do_flush = srv_unix_file_flush_method != SRV_UNIX_O_DSYNC;
#else
bool do_flush = true;
#endif
if (do_flush) {
log_group_t* group = UT_LIST_GET_FIRST(log_sys->log_groups);
fil_flush(group->space_id);
log_sys->flushed_to_disk_lsn = log_sys->current_flush_lsn;
}
log_sys->n_pending_flushes--;
MONITOR_DEC(MONITOR_PENDING_LOG_FLUSH);
os_event_set(log_sys->flush_event);
}
/** Switch the log buffer in use, and copy the content of last block
from old log buffer to the head of the to be used one. Thus, buf_free and
buf_next_to_write would be changed accordingly */
static inline
void
log_buffer_switch()
{
ut_ad(log_mutex_own());
ut_ad(log_write_mutex_own());
const byte* old_buf = log_sys->buf;
ulint area_end = ut_calc_align(log_sys->buf_free,
OS_FILE_LOG_BLOCK_SIZE);
if (log_sys->first_in_use) {
ut_ad(log_sys->buf == ut_align(log_sys->buf_ptr,
OS_FILE_LOG_BLOCK_SIZE));
log_sys->buf += log_sys->buf_size;
} else {
log_sys->buf -= log_sys->buf_size;
ut_ad(log_sys->buf == ut_align(log_sys->buf_ptr,
OS_FILE_LOG_BLOCK_SIZE));
}
log_sys->first_in_use = !log_sys->first_in_use;
/* Copy the last block to new buf */
ut_memcpy(log_sys->buf,
old_buf + area_end - OS_FILE_LOG_BLOCK_SIZE,
OS_FILE_LOG_BLOCK_SIZE);
log_sys->buf_free %= OS_FILE_LOG_BLOCK_SIZE;
log_sys->buf_next_to_write = log_sys->buf_free;
}
/** Ensure that the log has been written to the log file up to a given
log entry (such as that of a transaction commit). Start a new write, or
wait and check if an already running write is covering the request.
@param[in] lsn log sequence number that should be
included in the redo log file write
@param[in] flush_to_disk whether the written log should also
be flushed to the file system */
void
log_write_up_to(
lsn_t lsn,
bool flush_to_disk)
{
#ifdef UNIV_DEBUG
ulint loop_count = 0;
#endif /* UNIV_DEBUG */
byte* write_buf;
lsn_t write_lsn;
ut_ad(!srv_read_only_mode);
if (recv_no_ibuf_operations) {
/* Recovery is running and no operations on the log files are
allowed yet (the variable name .._no_ibuf_.. is misleading) */
return;
}
loop:
ut_ad(++loop_count < 128);
#if UNIV_WORD_SIZE > 7
/* We can do a dirty read of LSN. */
/* NOTE: Currently doesn't do dirty read for
(flush_to_disk == true) case, because the log_mutex
contention also works as the arbitrator for write-IO
(fsync) bandwidth between log files and data files. */
os_rmb;
if (!flush_to_disk && log_sys->write_lsn >= lsn) {
return;
}
#endif
log_write_mutex_enter();
ut_ad(!recv_no_log_write);
lsn_t limit_lsn = flush_to_disk
? log_sys->flushed_to_disk_lsn
: log_sys->write_lsn;
if (limit_lsn >= lsn) {
log_write_mutex_exit();
return;
}
#ifdef _WIN32
# ifndef UNIV_HOTBACKUP
/* write requests during fil_flush() might not be good for Windows */
if (log_sys->n_pending_flushes > 0
|| !os_event_is_set(log_sys->flush_event)) {
log_write_mutex_exit();
os_event_wait(log_sys->flush_event);
goto loop;
}
# else
if (log_sys->n_pending_flushes > 0) {
goto loop;
}
# endif /* !UNIV_HOTBACKUP */
#endif /* _WIN32 */
/* If it is a write call we should just go ahead and do it
as we checked that write_lsn is not where we'd like it to
be. If we have to flush as well then we check if there is a
pending flush and based on that we wait for it to finish
before proceeding further. */
if (flush_to_disk
&& (log_sys->n_pending_flushes > 0
|| !os_event_is_set(log_sys->flush_event))) {
/* Figure out if the current flush will do the job
for us. */
bool work_done = log_sys->current_flush_lsn >= lsn;
log_write_mutex_exit();
os_event_wait(log_sys->flush_event);
if (work_done) {
return;
} else {
goto loop;
}
}
log_mutex_enter();
if (!flush_to_disk
&& log_sys->buf_free == log_sys->buf_next_to_write) {
/* Nothing to write and no flush to disk requested */
log_mutex_exit_all();
return;
}
log_group_t* group;
ulint start_offset;
ulint end_offset;
ulint area_start;
ulint area_end;
ulong write_ahead_size = srv_log_write_ahead_size;
ulint pad_size;
DBUG_PRINT("ib_log", ("write " LSN_PF " to " LSN_PF,
log_sys->write_lsn,
log_sys->lsn));
if (flush_to_disk) {
log_sys->n_pending_flushes++;
log_sys->current_flush_lsn = log_sys->lsn;
MONITOR_INC(MONITOR_PENDING_LOG_FLUSH);
os_event_reset(log_sys->flush_event);
if (log_sys->buf_free == log_sys->buf_next_to_write) {
/* Nothing to write, flush only */
log_mutex_exit_all();
log_write_flush_to_disk_low();
return;
}
}
start_offset = log_sys->buf_next_to_write;
end_offset = log_sys->buf_free;
area_start = ut_calc_align_down(start_offset, OS_FILE_LOG_BLOCK_SIZE);
area_end = ut_calc_align(end_offset, OS_FILE_LOG_BLOCK_SIZE);
ut_ad(area_end - area_start > 0);
log_block_set_flush_bit(log_sys->buf + area_start, TRUE);
log_block_set_checkpoint_no(
log_sys->buf + area_end - OS_FILE_LOG_BLOCK_SIZE,
log_sys->next_checkpoint_no);
write_lsn = log_sys->lsn;
write_buf = log_sys->buf;
log_buffer_switch();
group = UT_LIST_GET_FIRST(log_sys->log_groups);
log_group_set_fields(group, log_sys->write_lsn);
log_mutex_exit();
/* Calculate pad_size if needed. */
pad_size = 0;
if (write_ahead_size > OS_FILE_LOG_BLOCK_SIZE) {
lsn_t end_offset;
ulint end_offset_in_unit;
end_offset = log_group_calc_lsn_offset(
ut_uint64_align_up(write_lsn,
OS_FILE_LOG_BLOCK_SIZE),
group);
end_offset_in_unit = (ulint) (end_offset % write_ahead_size);
if (end_offset_in_unit > 0
&& (area_end - area_start) > end_offset_in_unit) {
/* The first block in the unit was initialized
after the last writing.
Needs to be written padded data once. */
pad_size = write_ahead_size - end_offset_in_unit;
if (area_end + pad_size > log_sys->buf_size) {
pad_size = log_sys->buf_size - area_end;
}
::memset(write_buf + area_end, 0, pad_size);
}
}
/* Do the write to the log files */
log_group_write_buf(
group, write_buf + area_start,
area_end - area_start + pad_size,
#ifdef UNIV_DEBUG
pad_size,
#endif /* UNIV_DEBUG */
ut_uint64_align_down(log_sys->write_lsn,
OS_FILE_LOG_BLOCK_SIZE),
start_offset - area_start);
srv_stats.log_padded.add(pad_size);
log_sys->write_lsn = write_lsn;
#ifndef _WIN32
if (srv_unix_file_flush_method == SRV_UNIX_O_DSYNC) {
/* O_SYNC means the OS did not buffer the log file at all:
so we have also flushed to disk what we have written */
log_sys->flushed_to_disk_lsn = log_sys->write_lsn;
}
#endif /* !_WIN32 */
log_write_mutex_exit();
if (flush_to_disk) {
log_write_flush_to_disk_low();
}
}
/** write to the log file up to the last log entry.
@param[in] sync whether we want the written log
also to be flushed to disk. */
void
log_buffer_flush_to_disk(
bool sync)
{
ut_ad(!srv_read_only_mode);
log_write_up_to(log_get_lsn(), sync);
}
/****************************************************************//**
This functions writes the log buffer to the log file and if 'flush'
is set it forces a flush of the log file as well. This is meant to be
called from background master thread only as it does not wait for
the write (+ possible flush) to finish. */
void
log_buffer_sync_in_background(
/*==========================*/
bool flush) /*!< in: flush the logs to disk */
{
lsn_t lsn;
log_mutex_enter();
lsn = log_sys->lsn;
if (flush
&& log_sys->n_pending_flushes > 0
&& log_sys->current_flush_lsn >= lsn) {
/* The write + flush will write enough */
log_mutex_exit();
return;
}
log_mutex_exit();
log_write_up_to(lsn, flush);
}
/********************************************************************
Tries to establish a big enough margin of free space in the log buffer, such
that a new log entry can be catenated without an immediate need for a flush. */
static
void
log_flush_margin(void)
/*==================*/
{
log_t* log = log_sys;
lsn_t lsn = 0;
log_mutex_enter();
if (log->buf_free > log->max_buf_free) {
/* We can write during flush */
lsn = log->lsn;
}
log_mutex_exit();
if (lsn) {
log_write_up_to(lsn, false);
}
}
#ifndef UNIV_HOTBACKUP
/** Advances the smallest lsn for which there are unflushed dirty blocks in the
buffer pool.
NOTE: this function may only be called if the calling thread owns no
synchronization objects!
@param[in] new_oldest try to advance oldest_modified_lsn at least to
this lsn
@return false if there was a flush batch of the same type running,
which means that we could not start this flush batch */
static
bool
log_preflush_pool_modified_pages(
lsn_t new_oldest)
{
bool success;
if (recv_recovery_on) {
/* If the recovery is running, we must first apply all
log records to their respective file pages to get the
right modify lsn values to these pages: otherwise, there
might be pages on disk which are not yet recovered to the
current lsn, and even after calling this function, we could
not know how up-to-date the disk version of the database is,
and we could not make a new checkpoint on the basis of the
info on the buffer pool only. */
recv_apply_hashed_log_recs(TRUE);
}
if (new_oldest == LSN_MAX
|| !buf_page_cleaner_is_active
|| srv_is_being_started) {
ulint n_pages;
success = buf_flush_lists(ULINT_MAX, new_oldest, &n_pages);
buf_flush_wait_batch_end(NULL, BUF_FLUSH_LIST);
if (!success) {
MONITOR_INC(MONITOR_FLUSH_SYNC_WAITS);
}
MONITOR_INC_VALUE_CUMULATIVE(
MONITOR_FLUSH_SYNC_TOTAL_PAGE,
MONITOR_FLUSH_SYNC_COUNT,
MONITOR_FLUSH_SYNC_PAGES,
n_pages);
} else {
/* better to wait for flushed by page cleaner */
if (srv_flush_sync) {
/* wake page cleaner for IO burst */
buf_flush_request_force(new_oldest);
}
buf_flush_wait_flushed(new_oldest);
success = true;
}
return(success);
}
#endif /* !UNIV_HOTBACKUP */
/******************************************************//**
Completes a checkpoint. */
static
void
log_complete_checkpoint(void)
/*=========================*/
{
ut_ad(log_mutex_own());
ut_ad(log_sys->n_pending_checkpoint_writes == 0);
log_sys->next_checkpoint_no++;
log_sys->last_checkpoint_lsn = log_sys->next_checkpoint_lsn;
MONITOR_SET(MONITOR_LSN_CHECKPOINT_AGE,
log_sys->lsn - log_sys->last_checkpoint_lsn);
DBUG_PRINT("ib_log", ("checkpoint ended at " LSN_PF
", flushed to " LSN_PF,
log_sys->last_checkpoint_lsn,
log_sys->flushed_to_disk_lsn));
rw_lock_x_unlock_gen(&(log_sys->checkpoint_lock), LOG_CHECKPOINT);
}
/******************************************************//**
Completes an asynchronous checkpoint info write i/o to a log file. */
static
void
log_io_complete_checkpoint(void)
/*============================*/
{
MONITOR_DEC(MONITOR_PENDING_CHECKPOINT_WRITE);
log_mutex_enter();
ut_ad(log_sys->n_pending_checkpoint_writes > 0);
if (--log_sys->n_pending_checkpoint_writes == 0) {
log_complete_checkpoint();
}
log_mutex_exit();
}
/******************************************************//**
Writes the checkpoint info to a log group header. */
static
void
log_group_checkpoint(
/*=================*/
log_group_t* group) /*!< in: log group */
{
lsn_t lsn_offset;
byte* buf;
ut_ad(!srv_read_only_mode);
ut_ad(log_mutex_own());
#if LOG_CHECKPOINT_SIZE > OS_FILE_LOG_BLOCK_SIZE
# error "LOG_CHECKPOINT_SIZE > OS_FILE_LOG_BLOCK_SIZE"
#endif
DBUG_PRINT("ib_log", ("checkpoint " UINT64PF " at " LSN_PF
" written to group " ULINTPF,
log_sys->next_checkpoint_no,
log_sys->next_checkpoint_lsn,
group->id));
buf = group->checkpoint_buf;
memset(buf, 0, OS_FILE_LOG_BLOCK_SIZE);
mach_write_to_8(buf + LOG_CHECKPOINT_NO, log_sys->next_checkpoint_no);
mach_write_to_8(buf + LOG_CHECKPOINT_LSN, log_sys->next_checkpoint_lsn);
lsn_offset = log_group_calc_lsn_offset(log_sys->next_checkpoint_lsn,
group);
mach_write_to_8(buf + LOG_CHECKPOINT_OFFSET, lsn_offset);
mach_write_to_8(buf + LOG_CHECKPOINT_LOG_BUF_SIZE, log_sys->buf_size);
log_block_set_checksum(buf, log_block_calc_checksum_crc32(buf));
MONITOR_INC(MONITOR_PENDING_CHECKPOINT_WRITE);
log_sys->n_log_ios++;
MONITOR_INC(MONITOR_LOG_IO);
ut_ad(LOG_CHECKPOINT_1 < univ_page_size.physical());
ut_ad(LOG_CHECKPOINT_2 < univ_page_size.physical());
if (log_sys->n_pending_checkpoint_writes++ == 0) {
rw_lock_x_lock_gen(&log_sys->checkpoint_lock,
LOG_CHECKPOINT);
}
/* Note: We alternate the physical place of the checkpoint info.
See the (next_checkpoint_no & 1) below. */
/* We send as the last parameter the group machine address
added with 1, as we want to distinguish between a normal log
file write and a checkpoint field write */
fil_io(IORequestLogWrite, false,
page_id_t(group->space_id, 0),
univ_page_size,
(log_sys->next_checkpoint_no & 1)
? LOG_CHECKPOINT_2 : LOG_CHECKPOINT_1,
OS_FILE_LOG_BLOCK_SIZE,
buf, (byte*) group + 1);
ut_ad(((ulint) group & 0x1UL) == 0);
}
#ifdef UNIV_HOTBACKUP
/******************************************************//**
Writes info to a buffer of a log group when log files are created in
backup restoration. */
void
log_reset_first_header_and_checkpoint(
/*==================================*/
byte* hdr_buf,/*!< in: buffer which will be written to the
start of the first log file */
ib_uint64_t start) /*!< in: lsn of the start of the first log file;
we pretend that there is a checkpoint at
start + LOG_BLOCK_HDR_SIZE */
{
byte* buf;
ib_uint64_t lsn;
mach_write_to_4(hdr_buf + LOG_HEADER_FORMAT,
LOG_HEADER_FORMAT_CURRENT);
mach_write_to_8(hdr_buf + LOG_HEADER_START_LSN, start);
lsn = start + LOG_BLOCK_HDR_SIZE;
/* Write the label of mysqlbackup --restore */
strcpy((char*)hdr_buf + LOG_HEADER_CREATOR, LOG_HEADER_CREATOR_CURRENT);
ut_sprintf_timestamp((char*) hdr_buf
+ (LOG_HEADER_CREATOR
+ (sizeof LOG_HEADER_CREATOR_CURRENT) - 1));
buf = hdr_buf + LOG_CHECKPOINT_1;
memset(buf, 0, OS_FILE_LOG_BLOCK_SIZE);
/*mach_write_to_8(buf + LOG_CHECKPOINT_NO, 0);*/
mach_write_to_8(buf + LOG_CHECKPOINT_LSN, lsn);
mach_write_to_8(buf + LOG_CHECKPOINT_OFFSET,
LOG_FILE_HDR_SIZE + LOG_BLOCK_HDR_SIZE);
mach_write_to_8(buf + LOG_CHECKPOINT_LOG_BUF_SIZE, 2 * 1024 * 1024);
log_block_set_checksum(buf, log_block_calc_checksum_crc32(buf));
}
#endif /* UNIV_HOTBACKUP */
#ifndef UNIV_HOTBACKUP
/** Read a log group header page to log_sys->checkpoint_buf.
@param[in] group log group
@param[in] header 0 or LOG_CHEKCPOINT_1 or LOG_CHECKPOINT2 */
void
log_group_header_read(
const log_group_t* group,
ulint header)
{
ut_ad(log_mutex_own());
log_sys->n_log_ios++;
MONITOR_INC(MONITOR_LOG_IO);
fil_io(IORequestLogRead, true,
page_id_t(group->space_id, header / univ_page_size.physical()),
univ_page_size, header % univ_page_size.physical(),
OS_FILE_LOG_BLOCK_SIZE, log_sys->checkpoint_buf, NULL);
}
/** Write checkpoint info to the log header and invoke log_mutex_exit().
@param[in] sync whether to wait for the write to complete */
void
log_write_checkpoint_info(
bool sync)
{
log_group_t* group;
ut_ad(log_mutex_own());
if (!srv_read_only_mode) {
for (group = UT_LIST_GET_FIRST(log_sys->log_groups);
group;
group = UT_LIST_GET_NEXT(log_groups, group)) {
log_group_checkpoint(group);
}
}
log_mutex_exit();
MONITOR_INC(MONITOR_NUM_CHECKPOINT);
if (sync) {
/* Wait for the checkpoint write to complete */
rw_lock_s_lock(&log_sys->checkpoint_lock);
rw_lock_s_unlock(&log_sys->checkpoint_lock);
DEBUG_SYNC_C("checkpoint_completed");
DBUG_EXECUTE_IF(
"crash_after_checkpoint",
DBUG_SUICIDE(););
}
}
/** Set extra data to be written to the redo log during checkpoint.
@param[in] buf data to be appended on checkpoint, or NULL
@return pointer to previous data to be appended on checkpoint */
mtr_buf_t*
log_append_on_checkpoint(
mtr_buf_t* buf)
{
log_mutex_enter();
mtr_buf_t* old = log_sys->append_on_checkpoint;
log_sys->append_on_checkpoint = buf;
log_mutex_exit();
return(old);
}
/** Make a checkpoint. Note that this function does not flush dirty
blocks from the buffer pool: it only checks what is lsn of the oldest
modification in the pool, and writes information about the lsn in
log files. Use log_make_checkpoint_at() to flush also the pool.
@param[in] sync whether to wait for the write to complete
@param[in] write_always force a write even if no log
has been generated since the latest checkpoint
@return true if success, false if a checkpoint write was already running */
bool
log_checkpoint(
bool sync,
bool write_always)
{
lsn_t oldest_lsn;
ut_ad(!srv_read_only_mode);
if (recv_recovery_is_on()) {
recv_apply_hashed_log_recs(TRUE);
}
#ifndef _WIN32
switch (srv_unix_file_flush_method) {
case SRV_UNIX_NOSYNC:
break;
case SRV_UNIX_O_DSYNC:
case SRV_UNIX_FSYNC:
case SRV_UNIX_LITTLESYNC:
case SRV_UNIX_O_DIRECT:
case SRV_UNIX_O_DIRECT_NO_FSYNC:
fil_flush_file_spaces(FIL_TYPE_TABLESPACE);
}
#endif /* !_WIN32 */
log_mutex_enter();
ut_ad(!recv_no_log_write);
oldest_lsn = log_buf_pool_get_oldest_modification();
/* Because log also contains headers and dummy log records,
log_buf_pool_get_oldest_modification() will return log_sys->lsn
if the buffer pool contains no dirty buffers.
We must make sure that the log is flushed up to that lsn.
If there are dirty buffers in the buffer pool, then our
write-ahead-logging algorithm ensures that the log has been
flushed up to oldest_lsn. */
ut_ad(oldest_lsn >= log_sys->last_checkpoint_lsn);
if (!write_always
&& oldest_lsn
<= log_sys->last_checkpoint_lsn + SIZE_OF_MLOG_CHECKPOINT) {
/* Do nothing, because nothing was logged (other than
a MLOG_CHECKPOINT marker) since the previous checkpoint. */
log_mutex_exit();
return(true);
}
/* Repeat the MLOG_FILE_NAME records after the checkpoint, in
case some log records between the checkpoint and log_sys->lsn
need them. Finally, write a MLOG_CHECKPOINT marker. Redo log
apply expects to see a MLOG_CHECKPOINT after the checkpoint,
except on clean shutdown, where the log will be empty after
the checkpoint.
It is important that we write out the redo log before any
further dirty pages are flushed to the tablespace files. At
this point, because log_mutex_own(), mtr_commit() in other
threads will be blocked, and no pages can be added to the
flush lists. */
lsn_t flush_lsn = oldest_lsn;
const bool do_write
= srv_shutdown_state == SRV_SHUTDOWN_NONE
|| flush_lsn != log_sys->lsn;
if (fil_names_clear(flush_lsn, do_write)) {
ut_ad(log_sys->lsn >= flush_lsn + SIZE_OF_MLOG_CHECKPOINT);
flush_lsn = log_sys->lsn;
}
log_mutex_exit();
log_write_up_to(flush_lsn, true);
DBUG_EXECUTE_IF(
"using_wa_checkpoint_middle",
if (write_always) {
DEBUG_SYNC_C("wa_checkpoint_middle");
const my_bool b = TRUE;
buf_flush_page_cleaner_disabled_debug_update(
NULL, NULL, NULL, &b);
dict_stats_disabled_debug_update(
NULL, NULL, NULL, &b);
srv_master_thread_disabled_debug_update(
NULL, NULL, NULL, &b);
});
log_mutex_enter();
ut_ad(log_sys->flushed_to_disk_lsn >= flush_lsn);
ut_ad(flush_lsn >= oldest_lsn);
if (log_sys->last_checkpoint_lsn >= oldest_lsn) {
log_mutex_exit();
return(true);
}
if (log_sys->n_pending_checkpoint_writes > 0) {
/* A checkpoint write is running */
log_mutex_exit();
if (sync) {
/* Wait for the checkpoint write to complete */
rw_lock_s_lock(&log_sys->checkpoint_lock);
rw_lock_s_unlock(&log_sys->checkpoint_lock);
}
return(false);
}
log_sys->next_checkpoint_lsn = oldest_lsn;
log_write_checkpoint_info(sync);
ut_ad(!log_mutex_own());
return(true);
}
/** Make a checkpoint at or after a specified LSN.
@param[in] lsn the log sequence number, or LSN_MAX
for the latest LSN
@param[in] write_always force a write even if no log
has been generated since the latest checkpoint */
void
log_make_checkpoint_at(
lsn_t lsn,
bool write_always)
{
/* Preflush pages synchronously */
while (!log_preflush_pool_modified_pages(lsn)) {
/* Flush as much as we can */
}
while (!log_checkpoint(true, write_always)) {
/* Force a checkpoint */
}
}
/****************************************************************//**
Tries to establish a big enough margin of free space in the log groups, such
that a new log entry can be catenated without an immediate need for a
checkpoint. NOTE: this function may only be called if the calling thread
owns no synchronization objects! */
static
void
log_checkpoint_margin(void)
/*=======================*/
{
log_t* log = log_sys;
lsn_t age;
lsn_t checkpoint_age;
ib_uint64_t advance;
lsn_t oldest_lsn;
bool success;
loop:
advance = 0;
log_mutex_enter();
ut_ad(!recv_no_log_write);
if (!log->check_flush_or_checkpoint) {
log_mutex_exit();
return;
}
oldest_lsn = log_buf_pool_get_oldest_modification();
age = log->lsn - oldest_lsn;
if (age > log->max_modified_age_sync) {
/* A flush is urgent: we have to do a synchronous preflush */
advance = age - log->max_modified_age_sync;
}
checkpoint_age = log->lsn - log->last_checkpoint_lsn;
bool checkpoint_sync;
bool do_checkpoint;
if (checkpoint_age > log->max_checkpoint_age) {
/* A checkpoint is urgent: we do it synchronously */
checkpoint_sync = true;
do_checkpoint = true;
} else if (checkpoint_age > log->max_checkpoint_age_async) {
/* A checkpoint is not urgent: do it asynchronously */
do_checkpoint = true;
checkpoint_sync = false;
log->check_flush_or_checkpoint = false;
} else {
do_checkpoint = false;
checkpoint_sync = false;
log->check_flush_or_checkpoint = false;
}
log_mutex_exit();
if (advance) {
lsn_t new_oldest = oldest_lsn + advance;
success = log_preflush_pool_modified_pages(new_oldest);
/* If the flush succeeded, this thread has done its part
and can proceed. If it did not succeed, there was another
thread doing a flush at the same time. */
if (!success) {
log_mutex_enter();
log->check_flush_or_checkpoint = true;
log_mutex_exit();
goto loop;
}
}
if (do_checkpoint) {
log_checkpoint(checkpoint_sync, FALSE);
if (checkpoint_sync) {
goto loop;
}
}
}
/******************************************************//**
Reads a specified log segment to a buffer. */
void
log_group_read_log_seg(
/*===================*/
byte* buf, /*!< in: buffer where to read */
log_group_t* group, /*!< in: log group */
lsn_t start_lsn, /*!< in: read area start */
lsn_t end_lsn) /*!< in: read area end */
{
ulint len;
lsn_t source_offset;
ut_ad(log_mutex_own());
loop:
source_offset = log_group_calc_lsn_offset(start_lsn, group);
ut_a(end_lsn - start_lsn <= ULINT_MAX);
len = (ulint) (end_lsn - start_lsn);
ut_ad(len != 0);
if ((source_offset % group->file_size) + len > group->file_size) {
/* If the above condition is true then len (which is ulint)
is > the expression below, so the typecast is ok */
len = (ulint) (group->file_size -
(source_offset % group->file_size));
}
log_sys->n_log_ios++;
MONITOR_INC(MONITOR_LOG_IO);
ut_a(source_offset / UNIV_PAGE_SIZE <= ULINT_MAX);
const ulint page_no
= (ulint) (source_offset / univ_page_size.physical());
fil_io(IORequestLogRead, true,
page_id_t(group->space_id, page_no),
univ_page_size,
(ulint) (source_offset % univ_page_size.physical()),
len, buf, NULL);
start_lsn += len;
buf += len;
if (start_lsn != end_lsn) {
goto loop;
}
}
/**
Checks that there is enough free space in the log to start a new query step.
Flushes the log buffer or makes a new checkpoint if necessary. NOTE: this
function may only be called if the calling thread owns no synchronization
objects! */
void
log_check_margins(void)
{
bool check;
do {
log_flush_margin();
log_checkpoint_margin();
log_mutex_enter();
ut_ad(!recv_no_log_write);
check = log_sys->check_flush_or_checkpoint;
log_mutex_exit();
} while (check);
}
/****************************************************************//**
Makes a checkpoint at the latest lsn and writes it to first page of each
data file in the database, so that we know that the file spaces contain
all modifications up to that lsn. This can only be called at database
shutdown. This function also writes all log in log files to the log archive. */
void
logs_empty_and_mark_files_at_shutdown(void)
/*=======================================*/
{
lsn_t lsn;
ulint count = 0;
ulint total_trx;
ulint pending_io;
enum srv_thread_type active_thd;
const char* thread_name;
ib::info() << "Starting shutdown...";
while (srv_fast_shutdown == 0 && trx_rollback_or_clean_is_active) {
/* we should wait until rollback after recovery end
for slow shutdown */
os_thread_sleep(100000);
}
/* Wait until the master thread and all other operations are idle: our
algorithm only works if the server is idle at shutdown */
srv_shutdown_state = SRV_SHUTDOWN_CLEANUP;
loop:
os_thread_sleep(100000);
count++;
/* We need the monitor threads to stop before we proceed with
a shutdown. */
thread_name = srv_any_background_threads_are_active();
if (thread_name != NULL) {
/* Print a message every 60 seconds if we are waiting
for the monitor thread to exit. Master and worker
threads check will be done later. */
if (srv_print_verbose_log && count > 600) {
ib::info() << "Waiting for " << thread_name
<< " to exit";
count = 0;
}
goto loop;
}
/* Check that there are no longer transactions, except for
PREPARED ones. We need this wait even for the 'very fast'
shutdown, because the InnoDB layer may have committed or
prepared transactions and we don't want to lose them. */
total_trx = trx_sys_any_active_transactions();
if (total_trx > 0) {
if (srv_print_verbose_log && count > 600) {
ib::info() << "Waiting for " << total_trx << " active"
<< " transactions to finish";
count = 0;
}
goto loop;
}
/* Check that the background threads are suspended */
active_thd = srv_get_active_thread_type();
if (active_thd != SRV_NONE) {
if (active_thd == SRV_PURGE) {
srv_purge_wakeup();
}
/* The srv_lock_timeout_thread, srv_error_monitor_thread
and srv_monitor_thread should already exit by now. The
only threads to be suspended are the master threads
and worker threads (purge threads). Print the thread
type if any of such threads not in suspended mode */
if (srv_print_verbose_log && count > 600) {
const char* thread_type = "<null>";
switch (active_thd) {
case SRV_NONE:
/* This shouldn't happen because we've
already checked for this case before
entering the if(). We handle it here
to avoid a compiler warning. */
ut_error;
case SRV_WORKER:
thread_type = "worker threads";
break;
case SRV_MASTER:
thread_type = "master thread";
break;
case SRV_PURGE:
thread_type = "purge thread";
break;
}
ib::info() << "Waiting for " << thread_type
<< " to be suspended";
count = 0;
}
goto loop;
}
/* At this point only page_cleaner should be active. We wait
here to let it complete the flushing of the buffer pools
before proceeding further. */
srv_shutdown_state = SRV_SHUTDOWN_FLUSH_PHASE;
count = 0;
while (buf_page_cleaner_is_active) {
++count;
os_thread_sleep(100000);
if (srv_print_verbose_log && count > 600) {
ib::info() << "Waiting for page_cleaner to"
" finish flushing of buffer pool";
count = 0;
}
}
log_mutex_enter();
const ulint n_write = log_sys->n_pending_checkpoint_writes;
const ulint n_flush = log_sys->n_pending_flushes;
log_mutex_exit();
if (n_write != 0 || n_flush != 0) {
if (srv_print_verbose_log && count > 600) {
ib::info() << "Pending checkpoint_writes: " << n_write
<< ". Pending log flush writes: " << n_flush;
count = 0;
}
goto loop;
}
pending_io = buf_pool_check_no_pending_io();
if (pending_io) {
if (srv_print_verbose_log && count > 600) {
ib::info() << "Waiting for " << pending_io << " buffer"
" page I/Os to complete";
count = 0;
}
goto loop;
}
if (srv_fast_shutdown == 2) {
if (!srv_read_only_mode) {
ib::info() << "MySQL has requested a very fast"
" shutdown without flushing the InnoDB buffer"
" pool to data files. At the next mysqld"
" startup InnoDB will do a crash recovery!";
/* In this fastest shutdown we do not flush the
buffer pool:
it is essentially a 'crash' of the InnoDB server.
Make sure that the log is all flushed to disk, so
that we can recover all committed transactions in
a crash recovery. We must not write the lsn stamps
to the data files, since at a startup InnoDB deduces
from the stamps if the previous shutdown was clean. */
log_buffer_flush_to_disk();
/* Check that the background threads stay suspended */
thread_name = srv_any_background_threads_are_active();
if (thread_name != NULL) {
ib::warn() << "Background thread "
<< thread_name << " woke up during"
" shutdown";
goto loop;
}
}
srv_shutdown_state = SRV_SHUTDOWN_LAST_PHASE;
fil_close_all_files();
thread_name = srv_any_background_threads_are_active();
ut_a(!thread_name);
return;
}
if (!srv_read_only_mode) {
log_make_checkpoint_at(LSN_MAX, TRUE);
}
log_mutex_enter();
lsn = log_sys->lsn;
ut_ad(lsn >= log_sys->last_checkpoint_lsn);
log_mutex_exit();
/** If innodb_force_recovery is set to 6 then log_sys doesn't
have recent checkpoint information. So last checkpoint lsn
will never be equal to current lsn. */
const bool is_last = ((srv_force_recovery == SRV_FORCE_NO_LOG_REDO
&& lsn == log_sys->last_checkpoint_lsn
+ LOG_BLOCK_HDR_SIZE)
|| lsn == log_sys->last_checkpoint_lsn);
if (!is_last) {
goto loop;
}
/* Check that the background threads stay suspended */
thread_name = srv_any_background_threads_are_active();
if (thread_name != NULL) {
ib::warn() << "Background thread " << thread_name << " woke up"
" during shutdown";
goto loop;
}
if (!srv_read_only_mode) {
fil_flush_file_spaces(FIL_TYPE_TABLESPACE);
fil_flush_file_spaces(FIL_TYPE_LOG);
}
/* The call fil_write_flushed_lsn() will bypass the buffer
pool: therefore it is essential that the buffer pool has been
completely flushed to disk! (We do not call fil_write... if the
'very fast' shutdown is enabled.) */
if (!buf_all_freed()) {
if (srv_print_verbose_log && count > 600) {
ib::info() << "Waiting for dirty buffer pages to be"
" flushed";
count = 0;
}
goto loop;
}
srv_shutdown_state = SRV_SHUTDOWN_LAST_PHASE;
/* Make some checks that the server really is quiet */
srv_thread_type type = srv_get_active_thread_type();
ut_a(type == SRV_NONE);
bool freed = buf_all_freed();
ut_a(freed);
ut_a(lsn == log_sys->lsn);
if (lsn < srv_start_lsn) {
ib::error() << "Log sequence number at shutdown " << lsn
<< " is lower than at startup " << srv_start_lsn
<< "!";
}
srv_shutdown_lsn = lsn;
if (!srv_read_only_mode) {
fil_write_flushed_lsn(lsn);
}
fil_close_all_files();
/* Make some checks that the server really is quiet */
type = srv_get_active_thread_type();
ut_a(type == SRV_NONE);
freed = buf_all_freed();
ut_a(freed);
ut_a(lsn == log_sys->lsn);
}
/******************************************************//**
Peeks the current lsn.
@return TRUE if success, FALSE if could not get the log system mutex */
ibool
log_peek_lsn(
/*=========*/
lsn_t* lsn) /*!< out: if returns TRUE, current lsn is here */
{
if (0 == mutex_enter_nowait(&(log_sys->mutex))) {
*lsn = log_sys->lsn;
log_mutex_exit();
return(TRUE);
}
return(FALSE);
}
/******************************************************//**
Prints info of the log. */
void
log_print(
/*======*/
FILE* file) /*!< in: file where to print */
{
double time_elapsed;
time_t current_time;
log_mutex_enter();
fprintf(file,
"Log sequence number " LSN_PF "\n"
"Log flushed up to " LSN_PF "\n"
"Pages flushed up to " LSN_PF "\n"
"Last checkpoint at " LSN_PF "\n",
log_sys->lsn,
log_sys->flushed_to_disk_lsn,
log_buf_pool_get_oldest_modification(),
log_sys->last_checkpoint_lsn);
current_time = time(NULL);
time_elapsed = difftime(current_time,
log_sys->last_printout_time);
if (time_elapsed <= 0) {
time_elapsed = 1;
}
fprintf(file,
ULINTPF " pending log flushes, "
ULINTPF " pending chkp writes\n"
ULINTPF " log i/o's done, %.2f log i/o's/second\n",
log_sys->n_pending_flushes,
log_sys->n_pending_checkpoint_writes,
log_sys->n_log_ios,
static_cast<double>(
log_sys->n_log_ios - log_sys->n_log_ios_old)
/ time_elapsed);
log_sys->n_log_ios_old = log_sys->n_log_ios;
log_sys->last_printout_time = current_time;
log_mutex_exit();
}
/**********************************************************************//**
Refreshes the statistics used to print per-second averages. */
void
log_refresh_stats(void)
/*===================*/
{
log_sys->n_log_ios_old = log_sys->n_log_ios;
log_sys->last_printout_time = time(NULL);
}
/********************************************************//**
Closes a log group. */
static
void
log_group_close(
/*===========*/
log_group_t* group) /* in,own: log group to close */
{
ulint i;
for (i = 0; i < group->n_files; i++) {
ut_free(group->file_header_bufs_ptr[i]);
}
ut_free(group->file_header_bufs_ptr);
ut_free(group->file_header_bufs);
ut_free(group->checkpoint_buf_ptr);
ut_free(group);
}
/********************************************************//**
Closes all log groups. */
void
log_group_close_all(void)
/*=====================*/
{
log_group_t* group;
group = UT_LIST_GET_FIRST(log_sys->log_groups);
while (UT_LIST_GET_LEN(log_sys->log_groups) > 0) {
log_group_t* prev_group = group;
group = UT_LIST_GET_NEXT(log_groups, group);
UT_LIST_REMOVE(log_sys->log_groups, prev_group);
log_group_close(prev_group);
}
}
/********************************************************//**
Shutdown the log system but do not release all the memory. */
void
log_shutdown(void)
/*==============*/
{
log_group_close_all();
ut_free(log_sys->buf_ptr);
log_sys->buf_ptr = NULL;
log_sys->buf = NULL;
ut_free(log_sys->checkpoint_buf_ptr);
log_sys->checkpoint_buf_ptr = NULL;
log_sys->checkpoint_buf = NULL;
os_event_destroy(log_sys->flush_event);
rw_lock_free(&log_sys->checkpoint_lock);
mutex_free(&log_sys->mutex);
mutex_free(&log_sys->write_mutex);
mutex_free(&log_sys->log_flush_order_mutex);
recv_sys_close();
}
/********************************************************//**
Free the log system data structures. */
void
log_mem_free(void)
/*==============*/
{
if (log_sys != NULL) {
recv_sys_mem_free();
ut_free(log_sys);
log_sys = NULL;
}
}
#endif /* !UNIV_HOTBACKUP */
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