icarus::ns::util::ThreadSafeChangeMonitor< T, Comp > Class Template Reference

Helper to check if an object has changed. Thread-safe. More...

#include <ChangeMonitor.h>

Inheritance diagram for icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >:

Public Member Functions
std::optional< Data_t >	update (Data_t const &currentObj)
	Returns the old object if different from newObj. More...
std::optional< Data_t >	operator() (Data_t const &currentObj)
	As update(). More...
bool	hasReference () const
	Returns whether a reference value is present. More...
Data_t const &	reference () const
Public Member Functions inherited from icarus::ns::util::ChangeMonitor< T, Comp >
	ChangeMonitor (Comparison_t comp=Comparison_t{})
	Default constructor: starts with no reference value. More...
	ChangeMonitor (Data_t const &ref, Comp comp=Comp{})
	Constructor: starts with ref as the reference value. More...
std::optional< Data_t >	update (Data_t const &currentObj)
	Returns the old object if different from newObj. More...
std::optional< Data_t >	operator() (Data_t const &currentObj)
	As update(). More...
bool	hasReference () const
	Returns whether a reference value is present. More...
Data_t const &	reference () const
	Returns the reference value; undefined if hasReference() is false. More...

Private Types
using	Base_t = ChangeMonitor< T, Comp >
using	Data_t = typename Base_t::Data_t

Private Attributes
std::mutex	fLock

Additional Inherited Members
Public Types inherited from icarus::ns::util::ChangeMonitor< T, Comp >
using	Data_t = T
	Type of the object being monitored. More...
using	Comparison_t = Comp
	Type of object for reference comparison. More...

Detailed Description

template<typename T, typename Comp = std::equal_to<T>>
class icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >

Helper to check if an object has changed. Thread-safe.

Template Parameters

T	type of the object
Comp	type of the comparison between T objects

This class operates like ChangeMonitor, but it is made thread-safe by the use of a mutex.

Note

This class is actually only partially thread-safe: the member reference() is effectively not, since it returns a reference that can be then modified by another thread while accessed (read only) by another.

Definition at line 162 of file ChangeMonitor.h.

Member Typedef Documentation

template<typename T, typename Comp = std::equal_to<T>>

using icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::Base_t = ChangeMonitor<T, Comp>

private

Definition at line 164 of file ChangeMonitor.h.

template<typename T, typename Comp = std::equal_to<T>>

using icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::Data_t = typename Base_t::Data_t

private

Definition at line 165 of file ChangeMonitor.h.

Member Function Documentation

template<typename T, typename Comp = std::equal_to<T>>

bool icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::hasReference ( ) const

inline

Returns whether a reference value is present.

Definition at line 191 of file ChangeMonitor.h.

      { std::lock_guard lg { fLock }; return Base_t::hasReference(); }

template<typename T, typename Comp = std::equal_to<T>>

std::optional<Data_t> icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::operator() ( Data_t const &  currentObj )

inline

As update().

Definition at line 187 of file ChangeMonitor.h.

      { return update(currentObj); }

template<typename T, typename Comp = std::equal_to<T>>

Data_t const& icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::reference ( ) const

inline

Returns the reference value; undefined if hasReference() is false.

Note

While the method is thread-safe, it returns a reference to a mutable object.

Definition at line 197 of file ChangeMonitor.h.

      { std::lock_guard lg { fLock }; return Base_t::reference(); }

template<typename T, typename Comp = std::equal_to<T>>

std::optional<Data_t> icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::update ( Data_t const &  currentObj )

inline

Returns the old object if different from newObj.

Parameters

currentObj

the current object value

Returns

the old reference if different from currentObj, or no value

See Also

ChangeMonitor::update()

See ChangeMonitor::update() for details.

Definition at line 183 of file ChangeMonitor.h.

      { std::lock_guard lg { fLock }; return Base_t::update(currentObj); }

Member Data Documentation

template<typename T, typename Comp = std::equal_to<T>>

std::mutex icarus::ns::util::ThreadSafeChangeMonitor< T, Comp >::fLock

mutableprivate

Definition at line 167 of file ChangeMonitor.h.

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

• ChangeMonitor.h