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mariadb/include/log0log.h
Vadim Tkachenko d6c7789c34 Initial import of InnoDB-plugin 1.0.1 source tree
2008-11-30 22:10:29 -08:00

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/******************************************************
Database log
(c) 1995 Innobase Oy
Created 12/9/1995 Heikki Tuuri
*******************************************************/
#ifndef log0log_h
#define log0log_h
#include "univ.i"
#include "ut0byte.h"
#include "sync0sync.h"
#include "sync0rw.h"
typedef struct log_struct log_t;
typedef struct log_group_struct log_group_t;
#ifdef UNIV_DEBUG
extern ibool log_do_write;
extern ibool log_debug_writes;
#else /* UNIV_DEBUG */
# define log_do_write TRUE
#endif /* UNIV_DEBUG */
/* Wait modes for log_write_up_to */
#define LOG_NO_WAIT 91
#define LOG_WAIT_ONE_GROUP 92
#define LOG_WAIT_ALL_GROUPS 93
#define LOG_MAX_N_GROUPS 32
/********************************************************************
Sets the global variable log_fsp_current_free_limit. Also makes a checkpoint,
so that we know that the limit has been written to a log checkpoint field
on disk. */
UNIV_INTERN
void
log_fsp_current_free_limit_set_and_checkpoint(
/*==========================================*/
ulint limit); /* in: limit to set */
/***********************************************************************
Calculates where in log files we find a specified lsn. */
UNIV_INTERN
ulint
log_calc_where_lsn_is(
/*==================*/
/* out: log file number */
ib_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 */
ib_int64_t log_file_size); /* in: log file size
(including the header) */
/****************************************************************
Writes to the log the string given. The log must be released with
log_release. */
UNIV_INLINE
ib_uint64_t
log_reserve_and_write_fast(
/*=======================*/
/* out: end lsn of the log record,
zero if did not succeed */
byte* str, /* in: string */
ulint len, /* in: string length */
ib_uint64_t* start_lsn,/* out: start lsn of the log record */
ibool* success);/* out: TRUE if success */
/***************************************************************************
Releases the log mutex. */
UNIV_INLINE
void
log_release(void);
/*=============*/
/***************************************************************************
Checks if there is need for a log buffer flush or a new checkpoint, and does
this if yes. Any database operation should call this when it has modified
more than about 4 pages. NOTE that this function may only be called when the
OS thread owns no synchronization objects except the dictionary mutex. */
UNIV_INLINE
void
log_free_check(void);
/*================*/
/****************************************************************
Opens the log for log_write_low. The log must be closed with log_close and
released with log_release. */
UNIV_INTERN
ib_uint64_t
log_reserve_and_open(
/*=================*/
/* out: start lsn of the log record */
ulint len); /* in: length of data to be catenated */
/****************************************************************
Writes to the log the string given. It is assumed that the caller holds the
log mutex. */
UNIV_INTERN
void
log_write_low(
/*==========*/
byte* str, /* in: string */
ulint str_len); /* in: string length */
/****************************************************************
Closes the log. */
UNIV_INTERN
ib_uint64_t
log_close(void);
/*===========*/
/* out: lsn */
/****************************************************************
Gets the current lsn. */
UNIV_INLINE
ib_uint64_t
log_get_lsn(void);
/*=============*/
/* out: current lsn */
/**********************************************************
Initializes the log. */
UNIV_INTERN
void
log_init(void);
/*==========*/
/**********************************************************************
Inits a log group to the log system. */
UNIV_INTERN
void
log_group_init(
/*===========*/
ulint id, /* in: group id */
ulint n_files, /* in: number of log files */
ulint 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 archive_space_id); /* in: space id of the file space
which contains some archived log
files for this group; currently, only
for the first log group this is
used */
/**********************************************************
Completes an i/o to a log file. */
UNIV_INTERN
void
log_io_complete(
/*============*/
log_group_t* group); /* in: log group */
/**********************************************************
This function is called, e.g., when a transaction wants to commit. It checks
that the log has been written to the log file up to the last log entry written
by the transaction. If there is a flush running, it waits and checks if the
flush flushed enough. If not, starts a new flush. */
UNIV_INTERN
void
log_write_up_to(
/*============*/
ib_uint64_t lsn, /* in: log sequence number up to which
the log should be written,
IB_ULONGLONG_MAX if not specified */
ulint wait, /* in: LOG_NO_WAIT, LOG_WAIT_ONE_GROUP,
or LOG_WAIT_ALL_GROUPS */
ibool flush_to_disk);
/* in: TRUE if we want the written log
also to be flushed to disk */
/********************************************************************
Does a syncronous flush of the log buffer to disk. */
UNIV_INTERN
void
log_buffer_flush_to_disk(void);
/*==========================*/
/********************************************************************
Advances the smallest lsn for which there are unflushed dirty blocks in the
buffer pool and also may make a new checkpoint. NOTE: this function may only
be called if the calling thread owns no synchronization objects! */
UNIV_INTERN
ibool
log_preflush_pool_modified_pages(
/*=============================*/
/* out: FALSE if there was a
flush batch of the same type
running, which means that we
could not start this flush
batch */
ib_uint64_t new_oldest, /* in: try to advance
oldest_modified_lsn at least
to this lsn */
ibool sync); /* in: TRUE if synchronous
operation is desired */
/**********************************************************
Makes 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. */
UNIV_INTERN
ibool
log_checkpoint(
/*===========*/
/* out: TRUE if success, FALSE if a checkpoint
write was already running */
ibool sync, /* in: TRUE if synchronous operation is
desired */
ibool write_always); /* in: the function normally checks if the
the new checkpoint would have a greater
lsn than the previous one: if not, then no
physical write is done; by setting this
parameter TRUE, a physical write will always be
made to log files */
/********************************************************************
Makes a checkpoint at a given lsn or later. */
UNIV_INTERN
void
log_make_checkpoint_at(
/*===================*/
ib_uint64_t lsn, /* in: make a checkpoint at this or a
later lsn, if IB_ULONGLONG_MAX, makes
a checkpoint at the latest lsn */
ibool write_always); /* in: the function normally checks if
the the new checkpoint would have a
greater lsn than the previous one: if
not, then no physical write is done;
by setting this parameter TRUE, a
physical write will always be made to
log files */
/********************************************************************
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. */
UNIV_INTERN
void
logs_empty_and_mark_files_at_shutdown(void);
/*=======================================*/
/**********************************************************
Reads a checkpoint info from a log group header to log_sys->checkpoint_buf. */
UNIV_INTERN
void
log_group_read_checkpoint_info(
/*===========================*/
log_group_t* group, /* in: log group */
ulint field); /* in: LOG_CHECKPOINT_1 or LOG_CHECKPOINT_2 */
/***********************************************************************
Gets info from a checkpoint about a log group. */
UNIV_INTERN
void
log_checkpoint_get_nth_group_info(
/*==============================*/
byte* buf, /* in: buffer containing checkpoint info */
ulint n, /* in: nth slot */
ulint* file_no,/* out: archived file number */
ulint* offset);/* out: archived file offset */
/**********************************************************
Writes checkpoint info to groups. */
UNIV_INTERN
void
log_groups_write_checkpoint_info(void);
/*==================================*/
/**********************************************************
Writes info to a buffer of a log group when log files are created in
backup restoration. */
UNIV_INTERN
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 */
/************************************************************************
Starts an archiving operation. */
UNIV_INTERN
ibool
log_archive_do(
/*===========*/
/* out: TRUE if succeed, FALSE if an archiving
operation was already running */
ibool sync, /* in: TRUE if synchronous operation is desired */
ulint* n_bytes);/* out: archive log buffer size, 0 if nothing to
archive */
/********************************************************************
Writes the log contents to the archive up to the lsn when this function was
called, and stops the archiving. When archiving is started again, the archived
log file numbers start from a number one higher, so that the archiving will
not write again to the archived log files which exist when this function
returns. */
UNIV_INTERN
ulint
log_archive_stop(void);
/*==================*/
/* out: DB_SUCCESS or DB_ERROR */
/********************************************************************
Starts again archiving which has been stopped. */
UNIV_INTERN
ulint
log_archive_start(void);
/*===================*/
/* out: DB_SUCCESS or DB_ERROR */
/********************************************************************
Stop archiving the log so that a gap may occur in the archived log files. */
UNIV_INTERN
ulint
log_archive_noarchivelog(void);
/*==========================*/
/* out: DB_SUCCESS or DB_ERROR */
/********************************************************************
Start archiving the log so that a gap may occur in the archived log files. */
UNIV_INTERN
ulint
log_archive_archivelog(void);
/*========================*/
/* out: DB_SUCCESS or DB_ERROR */
/**********************************************************
Generates an archived log file name. */
UNIV_INTERN
void
log_archived_file_name_gen(
/*=======================*/
char* buf, /* in: buffer where to write */
ulint id, /* in: group id */
ulint file_no);/* in: file number */
/************************************************************************
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! */
UNIV_INTERN
void
log_check_margins(void);
/*===================*/
/**********************************************************
Reads a specified log segment to a buffer. */
UNIV_INTERN
void
log_group_read_log_seg(
/*===================*/
ulint type, /* in: LOG_ARCHIVE or LOG_RECOVER */
byte* buf, /* in: buffer where to read */
log_group_t* group, /* in: log group */
ib_uint64_t start_lsn, /* in: read area start */
ib_uint64_t end_lsn); /* in: read area end */
/**********************************************************
Writes a buffer to a log file group. */
UNIV_INTERN
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 */
ib_uint64_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 */
/************************************************************
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. */
UNIV_INTERN
void
log_group_set_fields(
/*=================*/
log_group_t* group, /* in: group */
ib_uint64_t lsn); /* in: lsn for which the values should be
set */
/**********************************************************
Calculates the data capacity of a log group, when the log file headers are not
included. */
UNIV_INTERN
ulint
log_group_get_capacity(
/*===================*/
/* out: capacity in bytes */
log_group_t* group); /* in: log group */
/****************************************************************
Gets a log block flush bit. */
UNIV_INLINE
ibool
log_block_get_flush_bit(
/*====================*/
/* out: TRUE if this block was the first
to be written in a log flush */
byte* log_block); /* in: log block */
/****************************************************************
Gets a log block number stored in the header. */
UNIV_INLINE
ulint
log_block_get_hdr_no(
/*=================*/
/* out: log block number stored in the block
header */
byte* log_block); /* in: log block */
/****************************************************************
Gets a log block data length. */
UNIV_INLINE
ulint
log_block_get_data_len(
/*===================*/
/* out: log block data length measured as a
byte offset from the block start */
byte* log_block); /* in: log block */
/****************************************************************
Sets the log block data length. */
UNIV_INLINE
void
log_block_set_data_len(
/*===================*/
byte* log_block, /* in: log block */
ulint len); /* in: data length */
/****************************************************************
Calculates the checksum for a log block. */
UNIV_INLINE
ulint
log_block_calc_checksum(
/*====================*/
/* out: checksum */
const byte* block); /* in: log block */
/****************************************************************
Gets a log block checksum field value. */
UNIV_INLINE
ulint
log_block_get_checksum(
/*===================*/
/* out: checksum */
const byte* log_block); /* in: log block */
/****************************************************************
Sets a log block checksum field value. */
UNIV_INLINE
void
log_block_set_checksum(
/*===================*/
byte* log_block, /* in: log block */
ulint checksum); /* in: checksum */
/****************************************************************
Gets a log block first mtr log record group offset. */
UNIV_INLINE
ulint
log_block_get_first_rec_group(
/*==========================*/
/* out: first mtr log record group byte offset
from the block start, 0 if none */
byte* log_block); /* in: log block */
/****************************************************************
Sets the log block first mtr log record group offset. */
UNIV_INLINE
void
log_block_set_first_rec_group(
/*==========================*/
byte* log_block, /* in: log block */
ulint offset); /* in: offset, 0 if none */
/****************************************************************
Gets a log block checkpoint number field (4 lowest bytes). */
UNIV_INLINE
ulint
log_block_get_checkpoint_no(
/*========================*/
/* out: checkpoint no (4 lowest bytes) */
byte* log_block); /* in: log block */
/****************************************************************
Initializes a log block in the log buffer. */
UNIV_INLINE
void
log_block_init(
/*===========*/
byte* log_block, /* in: pointer to the log buffer */
ib_uint64_t lsn); /* in: lsn within the log block */
/****************************************************************
Initializes a log block in the log buffer in the old, < 3.23.52 format, where
there was no checksum yet. */
UNIV_INLINE
void
log_block_init_in_old_format(
/*=========================*/
byte* log_block, /* in: pointer to the log buffer */
ib_uint64_t lsn); /* in: lsn within the log block */
/****************************************************************
Converts a lsn to a log block number. */
UNIV_INLINE
ulint
log_block_convert_lsn_to_no(
/*========================*/
/* out: log block number,
it is > 0 and <= 1G */
ib_uint64_t lsn); /* in: lsn of a byte within the block */
/**********************************************************
Prints info of the log. */
UNIV_INTERN
void
log_print(
/*======*/
FILE* file); /* in: file where to print */
/**********************************************************
Peeks the current lsn. */
UNIV_INTERN
ibool
log_peek_lsn(
/*=========*/
/* out: TRUE if success, FALSE if
could not get the log system mutex */
ib_uint64_t* lsn); /* out: if returns TRUE, current lsn is here */
/**************************************************************************
Refreshes the statistics used to print per-second averages. */
UNIV_INTERN
void
log_refresh_stats(void);
/*===================*/
extern log_t* log_sys;
/* Values used as flags */
#define LOG_FLUSH 7652559
#define LOG_CHECKPOINT 78656949
#define LOG_ARCHIVE 11122331
#define LOG_RECOVER 98887331
/* The counting of lsn's starts from this value: this must be non-zero */
#define LOG_START_LSN ((ib_uint64_t) (16 * OS_FILE_LOG_BLOCK_SIZE))
#define LOG_BUFFER_SIZE (srv_log_buffer_size * UNIV_PAGE_SIZE)
#define LOG_ARCHIVE_BUF_SIZE (srv_log_buffer_size * UNIV_PAGE_SIZE / 4)
/* Offsets of a log block header */
#define LOG_BLOCK_HDR_NO 0 /* block number which must be > 0 and
is allowed to wrap around at 2G; the
highest bit is set to 1 if this is the
first log block in a log flush write
segment */
#define LOG_BLOCK_FLUSH_BIT_MASK 0x80000000UL
/* mask used to get the highest bit in
the preceding field */
#define LOG_BLOCK_HDR_DATA_LEN 4 /* number of bytes of log written to
this block */
#define LOG_BLOCK_FIRST_REC_GROUP 6 /* offset of the first start of an
mtr log record group in this log block,
0 if none; if the value is the same
as LOG_BLOCK_HDR_DATA_LEN, it means
that the first rec group has not yet
been catenated to this log block, but
if it will, it will start at this
offset; an archive recovery can
start parsing the log records starting
from this offset in this log block,
if value not 0 */
#define LOG_BLOCK_CHECKPOINT_NO 8 /* 4 lower bytes of the value of
log_sys->next_checkpoint_no when the
log block was last written to: if the
block has not yet been written full,
this value is only updated before a
log buffer flush */
#define LOG_BLOCK_HDR_SIZE 12 /* size of the log block header in
bytes */
/* Offsets of a log block trailer from the end of the block */
#define LOG_BLOCK_CHECKSUM 4 /* 4 byte checksum of the log block
contents; in InnoDB versions
< 3.23.52 this did not contain the
checksum but the same value as
.._HDR_NO */
#define LOG_BLOCK_TRL_SIZE 4 /* trailer size in bytes */
/* Offsets for a checkpoint field */
#define LOG_CHECKPOINT_NO 0
#define LOG_CHECKPOINT_LSN 8
#define LOG_CHECKPOINT_OFFSET 16
#define LOG_CHECKPOINT_LOG_BUF_SIZE 20
#define LOG_CHECKPOINT_ARCHIVED_LSN 24
#define LOG_CHECKPOINT_GROUP_ARRAY 32
/* For each value < LOG_MAX_N_GROUPS the following 8 bytes: */
#define LOG_CHECKPOINT_ARCHIVED_FILE_NO 0
#define LOG_CHECKPOINT_ARCHIVED_OFFSET 4
#define LOG_CHECKPOINT_ARRAY_END (LOG_CHECKPOINT_GROUP_ARRAY\
+ LOG_MAX_N_GROUPS * 8)
#define LOG_CHECKPOINT_CHECKSUM_1 LOG_CHECKPOINT_ARRAY_END
#define LOG_CHECKPOINT_CHECKSUM_2 (4 + LOG_CHECKPOINT_ARRAY_END)
#define LOG_CHECKPOINT_FSP_FREE_LIMIT (8 + LOG_CHECKPOINT_ARRAY_END)
/* current fsp free limit in
tablespace 0, in units of one
megabyte; this information is only used
by ibbackup to decide if it can
truncate unused ends of
non-auto-extending data files in space
0 */
#define LOG_CHECKPOINT_FSP_MAGIC_N (12 + LOG_CHECKPOINT_ARRAY_END)
/* this magic number tells if the
checkpoint contains the above field:
the field was added to
InnoDB-3.23.50 */
#define LOG_CHECKPOINT_SIZE (16 + LOG_CHECKPOINT_ARRAY_END)
#define LOG_CHECKPOINT_FSP_MAGIC_N_VAL 1441231243
/* Offsets of a log file header */
#define LOG_GROUP_ID 0 /* log group number */
#define LOG_FILE_START_LSN 4 /* lsn of the start of data in this
log file */
#define LOG_FILE_NO 12 /* 4-byte archived log file number;
this field is only defined in an
archived log file */
#define LOG_FILE_WAS_CREATED_BY_HOT_BACKUP 16
/* a 32-byte field which contains
the string 'ibbackup' and the
creation time if the log file was
created by ibbackup --restore;
when mysqld is first time started
on the restored database, it can
print helpful info for the user */
#define LOG_FILE_ARCH_COMPLETED OS_FILE_LOG_BLOCK_SIZE
/* this 4-byte field is TRUE when
the writing of an archived log file
has been completed; this field is
only defined in an archived log file */
#define LOG_FILE_END_LSN (OS_FILE_LOG_BLOCK_SIZE + 4)
/* lsn where the archived log file
at least extends: actually the
archived log file may extend to a
later lsn, as long as it is within the
same log block as this lsn; this field
is defined only when an archived log
file has been completely written */
#define LOG_CHECKPOINT_1 OS_FILE_LOG_BLOCK_SIZE
/* first checkpoint field in the log
header; we write alternately to the
checkpoint fields when we make new
checkpoints; this field is only defined
in the first log file of a log group */
#define LOG_CHECKPOINT_2 (3 * OS_FILE_LOG_BLOCK_SIZE)
/* second checkpoint field in the log
header */
#define LOG_FILE_HDR_SIZE (4 * OS_FILE_LOG_BLOCK_SIZE)
#define LOG_GROUP_OK 301
#define LOG_GROUP_CORRUPTED 302
/* Log group consists of a number of log files, each of the same size; a log
group is implemented as a space in the sense of the module fil0fil. */
struct log_group_struct{
/* The following fields are protected by log_sys->mutex */
ulint id; /* log group id */
ulint n_files; /* number of files in the group */
ulint file_size; /* individual log file size in bytes,
including the log file header */
ulint space_id; /* file space which implements the log
group */
ulint state; /* LOG_GROUP_OK or
LOG_GROUP_CORRUPTED */
ib_uint64_t lsn; /* lsn used to fix coordinates within
the log group */
ulint lsn_offset; /* the offset of the above lsn */
ulint n_pending_writes;/* number of currently pending flush
writes for this log group */
byte** file_header_bufs;/* buffers for each file header in the
group */
/*-----------------------------*/
byte** archive_file_header_bufs;/* buffers for each file
header in the group */
ulint archive_space_id;/* file space which implements the log
group archive */
ulint archived_file_no;/* file number corresponding to
log_sys->archived_lsn */
ulint archived_offset;/* file offset corresponding to
log_sys->archived_lsn, 0 if we have
not yet written to the archive file
number archived_file_no */
ulint next_archived_file_no;/* during an archive write,
until the write is completed, we
store the next value for
archived_file_no here: the write
completion function then sets the new
value to ..._file_no */
ulint next_archived_offset; /* like the preceding field */
/*-----------------------------*/
ib_uint64_t scanned_lsn; /* used only in recovery: recovery scan
succeeded up to this lsn in this log
group */
byte* checkpoint_buf; /* checkpoint header is written from
this buffer to the group */
UT_LIST_NODE_T(log_group_t)
log_groups; /* list of log groups */
};
struct log_struct{
byte pad[64]; /* padding to prevent other memory
update hotspots from residing on the
same memory cache line */
ib_uint64_t lsn; /* log sequence number */
ulint buf_free; /* first free offset within the log
buffer */
mutex_t mutex; /* mutex protecting the log */
byte* buf; /* log buffer */
ulint buf_size; /* log buffer size in bytes */
ulint max_buf_free; /* recommended maximum value of
buf_free, after which the buffer is
flushed */
ulint old_buf_free; /* value of buf free when log was
last time opened; only in the debug
version */
ib_uint64_t old_lsn; /* value of lsn when log was last time
opened; only in the debug version */
ibool check_flush_or_checkpoint;
/* this is set to TRUE when there may
be need to flush the log buffer, or
preflush buffer pool pages, or make
a checkpoint; this MUST be TRUE when
lsn - last_checkpoint_lsn >
max_checkpoint_age; this flag is
peeked at by log_free_check(), which
does not reserve the log mutex */
UT_LIST_BASE_NODE_T(log_group_t)
log_groups; /* log groups */
/* The fields involved in the log buffer flush */
ulint buf_next_to_write;/* first offset in the log buffer
where the byte content may not exist
written to file, e.g., the start
offset of a log record catenated
later; this is advanced when a flush
operation is completed to all the log
groups */
ib_uint64_t written_to_some_lsn;
/* first log sequence number not yet
written to any log group; for this to
be advanced, it is enough that the
write i/o has been completed for any
one log group */
ib_uint64_t written_to_all_lsn;
/* first log sequence number not yet
written to some log group; for this to
be advanced, it is enough that the
write i/o has been completed for all
log groups */
ib_uint64_t write_lsn; /* end lsn for the current running
write */
ulint write_end_offset;/* the data in buffer has been written
up to this offset when the current
write ends: this field will then
be copied to buf_next_to_write */
ib_uint64_t current_flush_lsn;/* end lsn for the current running
write + flush operation */
ib_uint64_t flushed_to_disk_lsn;
/* how far we have written the log
AND flushed to disk */
ulint n_pending_writes;/* number of currently pending flushes
or writes */
/* NOTE on the 'flush' in names of the fields below: starting from
4.0.14, we separate the write of the log file and the actual fsync()
or other method to flush it to disk. The names below shhould really
be 'flush_or_write'! */
os_event_t no_flush_event; /* this event is in the reset state
when a flush or a write is running;
a thread should wait for this without
owning the log mutex, but NOTE that
to set or reset this event, the
thread MUST own the log mutex! */
ibool one_flushed; /* during a flush, this is first FALSE
and becomes TRUE when one log group
has been written or flushed */
os_event_t one_flushed_event;/* this event is reset when the
flush or write has not yet completed
for any log group; e.g., this means
that a transaction has been committed
when this is set; a thread should wait
for this without owning the log mutex,
but NOTE that to set or reset this
event, the thread MUST own the log
mutex! */
ulint n_log_ios; /* number of log i/os initiated thus
far */
ulint n_log_ios_old; /* number of log i/o's at the
previous printout */
time_t last_printout_time;/* when log_print was last time
called */
/* Fields involved in checkpoints */
ulint log_group_capacity; /* capacity of the log group; if
the checkpoint age exceeds this, it is
a serious error because it is possible
we will then overwrite log and spoil
crash recovery */
ulint max_modified_age_async;
/* when this recommended value for lsn
- buf_pool_get_oldest_modification()
is exceeded, we start an asynchronous
preflush of pool pages */
ulint max_modified_age_sync;
/* when this recommended value for lsn
- buf_pool_get_oldest_modification()
is exceeded, we start a synchronous
preflush of pool pages */
ulint adm_checkpoint_interval;
/* administrator-specified checkpoint
interval in terms of log growth in
bytes; the interval actually used by
the database can be smaller */
ulint max_checkpoint_age_async;
/* when this checkpoint age is exceeded
we start an asynchronous writing of a
new checkpoint */
ulint max_checkpoint_age;
/* this is the maximum allowed value
for lsn - last_checkpoint_lsn when a
new query step is started */
ib_uint64_t next_checkpoint_no;
/* next checkpoint number */
ib_uint64_t last_checkpoint_lsn;
/* latest checkpoint lsn */
ib_uint64_t next_checkpoint_lsn;
/* next checkpoint lsn */
ulint n_pending_checkpoint_writes;
/* number of currently pending
checkpoint writes */
rw_lock_t checkpoint_lock;/* this latch is x-locked when a
checkpoint write is running; a thread
should wait for this without owning
the log mutex */
byte* checkpoint_buf; /* checkpoint header is read to this
buffer */
#ifdef UNIV_LOG_ARCHIVE
/* Fields involved in archiving */
ulint archiving_state;/* LOG_ARCH_ON, LOG_ARCH_STOPPING
LOG_ARCH_STOPPED, LOG_ARCH_OFF */
ib_uint64_t archived_lsn; /* archiving has advanced to this
lsn */
ulint max_archived_lsn_age_async;
/* recommended maximum age of
archived_lsn, before we start
asynchronous copying to the archive */
ulint max_archived_lsn_age;
/* maximum allowed age for
archived_lsn */
ib_uint64_t next_archived_lsn;/* during an archive write,
until the write is completed, we
store the next value for
archived_lsn here: the write
completion function then sets the new
value to archived_lsn */
ulint archiving_phase;/* LOG_ARCHIVE_READ or
LOG_ARCHIVE_WRITE */
ulint n_pending_archive_ios;
/* number of currently pending reads
or writes in archiving */
rw_lock_t archive_lock; /* this latch is x-locked when an
archive write is running; a thread
should wait for this without owning
the log mutex */
ulint archive_buf_size;/* size of archive_buf */
byte* archive_buf; /* log segment is written to the
archive from this buffer */
os_event_t archiving_on; /* if archiving has been stopped,
a thread can wait for this event to
become signaled */
#endif /* UNIV_LOG_ARCHIVE */
};
#define LOG_ARCH_ON 71
#define LOG_ARCH_STOPPING 72
#define LOG_ARCH_STOPPING2 73
#define LOG_ARCH_STOPPED 74
#define LOG_ARCH_OFF 75
#ifndef UNIV_NONINL
#include "log0log.ic"
#endif
#endif
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