morph::exec::OwnerStrand Class Reference

One strand over a morph executor, usable wherever a morph executor is: the owner a component's state belongs to. More...

#include <owner_strand.hpp>

Inheritance diagram for morph::exec::OwnerStrand:

Public Member Functions
	OwnerStrand (::morph::exec::IExecutor &base)
	OwnerStrand (const OwnerStrand &)=delete
OwnerStrand &	operator= (const OwnerStrand &)=delete
	OwnerStrand (OwnerStrand &&)=delete
OwnerStrand &	operator= (OwnerStrand &&)=delete
	~OwnerStrand () override
	Closes the strand: what is still queued is dropped, and a task running on another thread is waited for.
void	post (std::function< void()> task) override
	Queues task after everything posted before it. A throw out of it is logged. Dropped once the strand is closed.
template<typename F>
void	postTask (F &&task)
	Queues task, held by value in the strand's one allocation for it, after everything posted before it. A throw out of it is logged. Dropped once the strand is closed.
bool	runningHere () const noexcept
	Whether the calling thread is inside one of this strand's tasks.
bool	idle () const
	Whether nothing is queued or running.
void	close ()
	Closes the strand, as the destructor does. Idempotent.
void	seal ()
	Refuses the strand's try-forms and keeps running what is queued; post is still admitted until close(). Idempotent.
Public Member Functions inherited from morph::exec::IExecutor
	IExecutor (const IExecutor &)=delete
IExecutor &	operator= (const IExecutor &)=delete
	IExecutor (IExecutor &&)=delete
IExecutor &	operator= (IExecutor &&)=delete
virtual bool	isSerial () const noexcept
	Whether this executor runs one task at a time, each after the tasks posted before it: a strand, a GUI loop, a pumped MainThreadExecutor.
::core::async::IExecutor &	coreExecutor () noexcept
	This executor as a core-cpp executor: the identity an core::async::ExecutorScope names.

Detailed Description

One strand over a morph executor, usable wherever a morph executor is: the owner a component's state belongs to.

Tasks run one at a time, in the order they were posted, on the threads of the base executor. A component keeps its state in tasks on one of these and needs no lock for it: RemoteServer keeps its registry here, and ReconnectCoordinator its reconnect sequence.

Every task runs inside an ExecutorScope naming this object's coreExecutor(), so inside a task runningOn(*this) is true — as is runningOn(base), whose scope the strand's batch runs within — and a coroutine that suspends in a task and resumes on the current executor comes back here. Outside every task both are false.

Being a morph::exec::IExecutor is what lets a component hand its owner out as a Completion's callback executor, or to a collaborator that must run on the same owner (SyncWorker, on the coordinator's strand).

Definition at line 39 of file owner_strand.hpp.

Constructor & Destructor Documentation

OwnerStrand()

morph::exec::OwnerStrand::OwnerStrand ( ::morph::exec::IExecutor & base )

inlineexplicit

Parameters

base	Where the strand's tasks run. Borrowed: it must outlive this object and keep running tasks until it is closed.

Definition at line 43 of file owner_strand.hpp.

~OwnerStrand()

morph::exec::OwnerStrand::~OwnerStrand ( )

inlineoverride

Closes the strand: what is still queued is dropped, and a task running on another thread is waited for.

Definition at line 54 of file owner_strand.hpp.

Member Function Documentation

post()

void morph::exec::OwnerStrand::post ( std::function< void()> task )

inlineoverridevirtual

Queues task after everything posted before it. A throw out of it is logged. Dropped once the strand is closed.

Parameters

task	Callable to run on the strand.

Implements morph::exec::IExecutor.

Definition at line 59 of file owner_strand.hpp.

postTask()

template<typename F>

void morph::exec::OwnerStrand::postTask ( F && task )

inline

Queues task, held by value in the strand's one allocation for it, after everything posted before it. A throw out of it is logged. Dropped once the strand is closed.

What a component posts to its own strand: no std::function in between, so a move-only capture is fine and a post costs one allocation.

Template Parameters

F	The callable's type.

Parameters

task	Callable to run on the strand.

Definition at line 72 of file owner_strand.hpp.

runningHere()

bool morph::exec::OwnerStrand::runningHere ( ) const

inlinenodiscardnoexcept

Whether the calling thread is inside one of this strand's tasks.

Returns

True inside a task, at any depth.

Definition at line 78 of file owner_strand.hpp.

idle()

bool morph::exec::OwnerStrand::idle ( ) const

inlinenodiscard

Whether nothing is queued or running.

Returns

True when idle. Racy by nature where other threads post.

Definition at line 82 of file owner_strand.hpp.

close()

void morph::exec::OwnerStrand::close ( )

inline

Closes the strand, as the destructor does. Idempotent.

Definition at line 85 of file owner_strand.hpp.

seal()

void morph::exec::OwnerStrand::seal ( )

inline

Refuses the strand's try-forms and keeps running what is queued; post is still admitted until close(). Idempotent.

Definition at line 89 of file owner_strand.hpp.

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

• morph/core/owner_strand.hpp