Slave_committed_queue Class Reference

Group Assigned Queue whose first element identifies first gap in committed sequence. More...

#include <rpl_rli_pdb.h>

Inheritance diagram for Slave_committed_queue:

Public Member Functions
void	update_current_binlog (const char *post_rotate)
	Slave_committed_queue (size_t max, uint n)
	~Slave_committed_queue ()
bool	count_done (Relay_log_info *rli)
size_t	move_queue_head (Slave_worker_array *ws)
	The queue is processed from the head item by item to purge items representing committed groups. More...
void	free_dynamic_items ()
	Method should be executed at slave system stop to cleanup dynamically allocated items that remained as unprocessed by Coordinator and Workers in their regular execution course. More...
Slave_job_group *	get_job_group (size_t ind)
size_t	en_queue (Slave_job_group *item)
	Assigns assigned_group_index to an index of enqueued item and returns it. More...
bool	de_queue (Slave_job_group *item)
	Dequeue from head. More...
bool	de_tail (Slave_job_group *item)
	Similar to de_queue() but removing an item from the tail side. More...
size_t	find_lwm (Slave_job_group **, size_t)
	Finds low-water mark of committed jobs in GAQ. More...
Public Member Functions inherited from circular_buffer_queue< Slave_job_group >
	circular_buffer_queue (size_t max)
	circular_buffer_queue ()
	~circular_buffer_queue ()=default
bool	de_queue (Slave_job_group *item)
	Content of the being dequeued item is copied to the arg-pointer location. More...
bool	de_tail (Slave_job_group *item)
	Similar to de_queue but extracting happens from the tail side. More...
size_t	en_queue (Slave_job_group *item)
	return the index where the arg item locates or an error encoded as a value circular_buffer_queue::error_result. More...
Slave_job_group *	head_queue ()
	return the value of data member of the head of the queue. More...
bool	in (size_t i)
size_t	get_length () const
bool	empty () const
bool	full () const

Public Attributes
bool	inited
Slave_job_group	lwm
Prealloced_array< ulonglong, 1 >	last_done
ulong	assigned_group_index
Public Attributes inherited from circular_buffer_queue< Slave_job_group >
Prealloced_array< Slave_job_group, 1 >	m_Q
size_t	capacity
	The capacity and maximum length of the queue in terms of element. More...
size_t	avail
	Its value modulo capacity is index of the element where the next element will be enqueued. More...
size_t	entry
	The head index of the queue. More...
std::atomic< size_t >	len
	Actual length. More...
bool	inited_queue

Additional Inherited Members
Static Public Attributes inherited from circular_buffer_queue< Slave_job_group >
static constexpr size_t	error_result

Detailed Description

Group Assigned Queue whose first element identifies first gap in committed sequence.

The head of the queue is therefore next to the low-water-mark.

Constructor & Destructor Documentation

Slave_committed_queue()

Slave_committed_queue::Slave_committed_queue	(	size_t	max,
		uint	n
	)

~Slave_committed_queue()

Slave_committed_queue::~Slave_committed_queue ( )

inline

Member Function Documentation

count_done()

bool Slave_committed_queue::count_done

(

Relay_log_info *

rli

)

de_queue()

bool Slave_committed_queue::de_queue ( Slave_job_group *  item )

inline

Dequeue from head.

Parameters

[out]

item

A pointer to the being dequeued item.

Returns

true if an element was returned, false if the queue was empty.

de_tail()

bool Slave_committed_queue::de_tail ( Slave_job_group *  item )

inline

Similar to de_queue() but removing an item from the tail side.

Parameters

[out]

item

A pointer to the being dequeued item.

Returns

true if an element was returned, false if the queue was empty.

en_queue()

size_t Slave_committed_queue::en_queue ( Slave_job_group *  item )

inline

Assigns assigned_group_index to an index of enqueued item and returns it.

find_lwm()

size_t Slave_committed_queue::find_lwm	(	Slave_job_group **	arg_g,
		size_t	start_index
	)

Finds low-water mark of committed jobs in GAQ.

That is an index below which all jobs are marked as done.

Notice the first available index is returned when the queue does not have any incomplete jobs. That includes cases of the empty and the full of complete jobs queue. A mutex protecting from concurrent LWM change by move_queue_head() (by Coordinator) should be taken by the caller.

Parameters

[out]	arg_g	a double pointer to Slave job descriptor item last marked with done-as-true boolean.
	start_index	a GAQ index to start/resume searching. Caller is to make sure the index points into assigned (occupied) range of circular buffer of GAQ.

Returns

GAQ index of the last consecutive done job, or the GAQ size when none is found.

free_dynamic_items()

void Slave_committed_queue::free_dynamic_items

(

)

Method should be executed at slave system stop to cleanup dynamically allocated items that remained as unprocessed by Coordinator and Workers in their regular execution course.

get_job_group()

Slave_job_group * Slave_committed_queue::get_job_group ( size_t  ind )

inline

move_queue_head()

size_t Slave_committed_queue::move_queue_head

(

Slave_worker_array *

ws

)

The queue is processed from the head item by item to purge items representing committed groups.

Progress in GAQ is assessed through comparison of GAQ index value with Worker's last_group_done_index. Purging breaks at a first discovered gap, that is an item that the assigned item->w_id'th Worker has not yet completed.

The caller is supposed to be the checkpoint handler.

A copy of the last discarded item containing the refreshed value of the committed low-water-mark is stored into lwm container member for further caller's processing. last_done is updated with the latest total_seqno for each Worker that was met during GAQ parse.

Note

dyn-allocated members of Slave_job_group such as group_relay_log_name as freed here.

Returns

number of discarded items

update_current_binlog()

void Slave_committed_queue::update_current_binlog

(

const char *

post_rotate

)

Member Data Documentation

assigned_group_index

ulong Slave_committed_queue::assigned_group_index

inited

bool Slave_committed_queue::inited

last_done

Prealloced_array<ulonglong, 1> Slave_committed_queue::last_done

lwm

Slave_job_group Slave_committed_queue::lwm

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The documentation for this class was generated from the following files:

• sql/rpl_rli_pdb.h
• sql/rpl_rli_pdb.cc