entt::basic_scheduler< Delta, Allocator > Class Template Reference

Cooperative scheduler for processes. More...

#include <scheduler.hpp>

Public Types
using	allocator_type = Allocator
	Allocator type.
using	size_type = std::size_t
	Unsigned integer type.
using	delta_type = Delta
	Unsigned integer type.

Public Member Functions
	basic_scheduler ()
	Default constructor.
	basic_scheduler (const allocator_type &allocator)
	Constructs a scheduler with a given allocator.
	basic_scheduler (basic_scheduler &&other) noexcept
	Move constructor.
	basic_scheduler (basic_scheduler &&other, const allocator_type &allocator) noexcept
	Allocator-extended move constructor.
basic_scheduler &	operator= (basic_scheduler &&other) noexcept
	Move assignment operator.
void	swap (basic_scheduler &other)
	Exchanges the contents with those of a given scheduler.
constexpr allocator_type	get_allocator () const noexcept
	Returns the associated allocator.
size_type	size () const noexcept
	Number of processes currently scheduled.
bool	empty () const noexcept
	Returns true if at least a process is currently scheduled.
void	clear ()
	Discards all scheduled processes.
template<typename Proc , typename... Args>
basic_scheduler &	attach (Args &&...args)
	Schedules a process for the next tick.
template<typename Func >
basic_scheduler &	attach (Func &&func)
	Schedules a process for the next tick.
template<typename Proc , typename... Args>
basic_scheduler &	then (Args &&...args)
	Sets a process as a continuation of the last scheduled process.
template<typename Func >
basic_scheduler &	then (Func &&func)
	Sets a process as a continuation of the last scheduled process.
void	update (const delta_type delta, void *data=nullptr)
	Updates all scheduled processes.
void	abort (const bool immediate=false)
	Aborts all scheduled processes.

Detailed Description

template<typename Delta, typename Allocator>
class entt::basic_scheduler< Delta, Allocator >

Cooperative scheduler for processes.

A cooperative scheduler runs processes and helps managing their life cycles.

Each process is invoked once per tick. If a process terminates, it's removed automatically from the scheduler and it's never invoked again.
A process can also have a child. In this case, the process is replaced with its child when it terminates if it returns with success. In case of errors, both the process and its child are discarded.

Example of use (pseudocode):

scheduler.attach([](auto delta, void *, auto succeed, auto fail) {
    // code
}).then<my_process>(arguments...);

In order to invoke all scheduled processes, call the update member function passing it the elapsed time to forward to the tasks.

See also

process

Template Parameters

Delta	Type to use to provide elapsed time.
Allocator	Type of allocator used to manage memory and elements.

Definition at line 82 of file scheduler.hpp.

Member Typedef Documentation

allocator_type

template<typename Delta , typename Allocator >

using entt::basic_scheduler< Delta, Allocator >::allocator_type = Allocator

Allocator type.

Definition at line 95 of file scheduler.hpp.

delta_type

template<typename Delta , typename Allocator >

using entt::basic_scheduler< Delta, Allocator >::delta_type = Delta

Unsigned integer type.

Definition at line 99 of file scheduler.hpp.

size_type

template<typename Delta , typename Allocator >

using entt::basic_scheduler< Delta, Allocator >::size_type = std::size_t

Unsigned integer type.

Definition at line 97 of file scheduler.hpp.

Constructor & Destructor Documentation

basic_scheduler() [1/4]

template<typename Delta , typename Allocator >

entt::basic_scheduler< Delta, Allocator >::basic_scheduler ( )

inline

Default constructor.

Definition at line 102 of file scheduler.hpp.

basic_scheduler() [2/4]

template<typename Delta , typename Allocator >

entt::basic_scheduler< Delta, Allocator >::basic_scheduler ( const allocator_type &  allocator )

inlineexplicit

Constructs a scheduler with a given allocator.

Parameters

allocator

The allocator to use.

Definition at line 109 of file scheduler.hpp.

basic_scheduler() [3/4]

template<typename Delta , typename Allocator >

entt::basic_scheduler< Delta, Allocator >::basic_scheduler ( basic_scheduler< Delta, Allocator > &&  other )

inlinenoexcept

Move constructor.

Parameters

other

The instance to move from.

Definition at line 116 of file scheduler.hpp.

basic_scheduler() [4/4]

template<typename Delta , typename Allocator >

entt::basic_scheduler< Delta, Allocator >::basic_scheduler ( basic_scheduler< Delta, Allocator > &&  other, const allocator_type &  allocator  )

inlinenoexcept

Allocator-extended move constructor.

Parameters

other	The instance to move from.
allocator	The allocator to use.

Definition at line 124 of file scheduler.hpp.

Member Function Documentation

abort()

template<typename Delta , typename Allocator >

void entt::basic_scheduler< Delta, Allocator >::abort ( const bool  immediate = false )

inline

Aborts all scheduled processes.

Unless an immediate operation is requested, the abort is scheduled for the next tick. Processes won't be executed anymore in any case.
Once a process is fully aborted and thus finished, it's discarded along with its child, if any.

Parameters

immediate

Requests an immediate operation.

Definition at line 340 of file scheduler.hpp.

attach() [1/2]

template<typename Delta , typename Allocator >

template<typename Proc , typename... Args>

basic_scheduler & entt::basic_scheduler< Delta, Allocator >::attach ( Args &&...  args )

inline

Schedules a process for the next tick.

Returned value can be used to attach a continuation for the last process. The continutation is scheduled automatically when the process terminates and only if the process returns with success.

Example of use (pseudocode):

// schedules a task in the form of a process class
scheduler.attach<my_process>(arguments...)
// appends a child in the form of a lambda function
.then([](auto delta, void *, auto succeed, auto fail) {
    // code
})
// appends a child in the form of another process class
.then<my_other_process>();

Template Parameters

Proc	Type of process to schedule.
Args	Types of arguments to use to initialize the process.

Parameters

args	Parameters to use to initialize the process.

Returns

This process scheduler.

Definition at line 209 of file scheduler.hpp.

attach() [2/2]

template<typename Delta , typename Allocator >

template<typename Func >

basic_scheduler & entt::basic_scheduler< Delta, Allocator >::attach ( Func &&  func )

inline

Schedules a process for the next tick.

A process can be either a lambda or a functor. The scheduler wraps both of them in a process adaptor internally.
The signature of the function call operator should be equivalent to the following:

void(Delta delta, void *data, auto succeed, auto fail);

Where:

• delta is the elapsed time.
• data is an opaque pointer to user data if any, nullptr otherwise.
• succeed is a function to call when a process terminates with success.
• fail is a function to call when a process terminates with errors.

The signature of the function call operator of both succeed and fail is equivalent to the following:

void();

Returned value can be used to attach a continuation for the last process. The continutation is scheduled automatically when the process terminates and only if the process returns with success.

Example of use (pseudocode):

// schedules a task in the form of a lambda function
scheduler.attach([](auto delta, void *, auto succeed, auto fail) {
    // code
})
// appends a child in the form of another lambda function
.then([](auto delta, void *, auto succeed, auto fail) {
    // code
})
// appends a child in the form of a process class
.then<my_process>(arguments...);

See also

process_adaptor

Template Parameters

Func	Type of process to schedule.

Parameters

func	Either a lambda or a functor to use as a process.

Returns

This process scheduler.

Definition at line 269 of file scheduler.hpp.

clear()

template<typename Delta , typename Allocator >

void entt::basic_scheduler< Delta, Allocator >::clear ( )

inline

Discards all scheduled processes.

Processes aren't aborted. They are discarded along with their children and never executed again.

Definition at line 179 of file scheduler.hpp.

empty()

template<typename Delta , typename Allocator >

bool entt::basic_scheduler< Delta, Allocator >::empty ( ) const

inlinenoexcept

Returns true if at least a process is currently scheduled.

Returns

True if there are scheduled processes, false otherwise.

Definition at line 169 of file scheduler.hpp.

get_allocator()

template<typename Delta , typename Allocator >

constexpr allocator_type entt::basic_scheduler< Delta, Allocator >::get_allocator ( ) const

inlineconstexprnoexcept

Returns the associated allocator.

Returns

The associated allocator.

Definition at line 153 of file scheduler.hpp.

operator=()

template<typename Delta , typename Allocator >

basic_scheduler & entt::basic_scheduler< Delta, Allocator >::operator= ( basic_scheduler< Delta, Allocator > &&  other )

inlinenoexcept

Move assignment operator.

Parameters

other

The instance to move from.

Returns

This scheduler.

Definition at line 134 of file scheduler.hpp.

size()

template<typename Delta , typename Allocator >

size_type entt::basic_scheduler< Delta, Allocator >::size ( ) const

inlinenoexcept

Number of processes currently scheduled.

Returns

Number of processes currently scheduled.

Definition at line 161 of file scheduler.hpp.

swap()

template<typename Delta , typename Allocator >

void entt::basic_scheduler< Delta, Allocator >::swap ( basic_scheduler< Delta, Allocator > &  other )

inline

Exchanges the contents with those of a given scheduler.

Parameters

other

Scheduler to exchange the content with.

Definition at line 144 of file scheduler.hpp.

then() [1/2]

template<typename Delta , typename Allocator >

template<typename Proc , typename... Args>

basic_scheduler & entt::basic_scheduler< Delta, Allocator >::then ( Args &&...  args )

inline

Sets a process as a continuation of the last scheduled process.

Template Parameters

Proc	Type of process to use as a continuation.
Args	Types of arguments to use to initialize the process.

Parameters

args	Parameters to use to initialize the process.

Returns

This process scheduler.

Definition at line 282 of file scheduler.hpp.

then() [2/2]

template<typename Delta , typename Allocator >

template<typename Func >

basic_scheduler & entt::basic_scheduler< Delta, Allocator >::then ( Func &&  func )

inline

Sets a process as a continuation of the last scheduled process.

Template Parameters

Func	Type of process to use as a continuation.

Parameters

func	Either a lambda or a functor to use as a process.

Returns

This process scheduler.

Definition at line 298 of file scheduler.hpp.

update()

template<typename Delta , typename Allocator >

void entt::basic_scheduler< Delta, Allocator >::update ( const delta_type  delta, void *  data = nullptr  )

inline

Updates all scheduled processes.

All scheduled processes are executed in no specific order.
If a process terminates with success, it's replaced with its child, if any. Otherwise, if a process terminates with an error, it's removed along with its child.

Parameters

delta	Elapsed time.
data	Optional data.

Definition at line 314 of file scheduler.hpp.

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

• src/entt/process/fwd.hpp
• src/entt/process/scheduler.hpp