mysql::scheduler::Scheduler_clock Class Reference

Interface for clock implementations scheduler uses to schedule tasks. More...

#include <scheduler_clock.h>

Inheritance diagram for mysql::scheduler::Scheduler_clock:

Public Types
using	Time_point_t = uint64_t

Public Member Functions
virtual	~Scheduler_clock ()=default
	Destructor. More...
virtual Time_point_t	now () const =0
	Gets current time delay, i.e. More...
virtual Time_point_t	start_time () const =0
	Gets clock starting point, i.e. More...
virtual bool	add_time (Task_id task_id, Time_point_t time)=0
	Subscribes a task to time processing window, delay since beginning of a schedule. More...
virtual bool	tick (Task_id task_id, Time_point_t time)=0
	Notify that task finished execution. More...
virtual bool	advances_independently () const
	Returns property of a clock - information on whether this clock is steered by task ticks or advances independently. More...
virtual bool	try_unblock ()
	Maintenance function for unblocking the clock. More...
virtual Scheduler_dependency_type	get_type () const
	Typical scheduler clock dependency type is end to start. More...

Detailed Description

Interface for clock implementations scheduler uses to schedule tasks.

Tasks are subscribing for execution at specific time window by calling the 'subscribe' method. A task is ready for execution, when its execution time, i.e. parameter of the 'subscribe' method, is equal or greater than current time point, determined by the 'now' method. When task finished its execution, it must call the 'tick' method.

Member Typedef Documentation

Time_point_t

using mysql::scheduler::Scheduler_clock::Time_point_t = uint64_t

Constructor & Destructor Documentation

~Scheduler_clock()

virtual mysql::scheduler::Scheduler_clock::~Scheduler_clock ( )

virtualdefault

Destructor.

Member Function Documentation

add_time()

virtual bool mysql::scheduler::Scheduler_clock::add_time ( Task_id  task_id, Time_point_t  time  )

pure virtual

Subscribes a task to time processing window, delay since beginning of a schedule.

Parameters

task_id	ID of the task being subscribed
time	Time window to which a task will be subscribed

Returns

True if task has been subscribed, false otherwise

Implemented in mysql::scheduler::Commit_order_clock, and mysql::scheduler::Clock_lwm_registry.

advances_independently()

virtual bool mysql::scheduler::Scheduler_clock::advances_independently ( ) const

inlinevirtual

Returns property of a clock - information on whether this clock is steered by task ticks or advances independently.

get_type()

virtual Scheduler_dependency_type mysql::scheduler::Scheduler_clock::get_type ( ) const

inlinevirtual

Typical scheduler clock dependency type is end to start.

Reimplemented in mysql::scheduler::Commit_order_clock.

now()

virtual Time_point_t mysql::scheduler::Scheduler_clock::now ( ) const

pure virtual

Gets current time delay, i.e.

current processing window value

Returns

Current time, i.e. current processing window value

Implemented in mysql::scheduler::Clock_lwm_registry, and mysql::scheduler::Commit_order_clock.

start_time()

virtual Time_point_t mysql::scheduler::Scheduler_clock::start_time ( ) const

pure virtual

Gets clock starting point, i.e.

first delay

Returns

clock start point

Implemented in mysql::scheduler::Clock_lwm_registry, and mysql::scheduler::Commit_order_clock.

tick()

virtual bool mysql::scheduler::Scheduler_clock::tick ( Task_id  task_id, Time_point_t  time  )

pure virtual

Notify that task finished execution.

Called by asynchronous workers executing task. When specific conditions are met, tick will advance the internal clock value.

Parameters

task_id	ID of the task that finished execution
time	Delay value the task was subscribed to

Returns

True if clock advanced its time

Implemented in mysql::scheduler::Commit_order_clock, and mysql::scheduler::Clock_lwm_registry.

try_unblock()

virtual bool mysql::scheduler::Scheduler_clock::try_unblock ( )

inlinevirtual

Maintenance function for unblocking the clock.

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

• libs/mysql/scheduler/scheduler_clock.h