uv::ref_count Class Reference

A reference counter with atomic increment/decrement. More...

#include "utility.hpp"

Public Types
using	type = long

Public Member Functions
	ref_count (const ref_count &)=delete
ref_count &	operator= (const ref_count &)=delete
	ref_count (ref_count &&)=delete
ref_count &	operator= (ref_count &&)=delete
type	get_value () const noexcept
void	set_value (type _count) noexcept
type	inc ()
type	dec () noexcept

Detailed Description

A reference counter with atomic increment/decrement.

The default constructor creates a new ref_count object with the count value = 1.

Atomic operations on the ref_count object provide the following memory ordering semantics:

Member function	Memory ordering
get_value()	acquire
set_value()	release
inc()	relaxed
dec()	release

Thus the client code can use get_value() function to check the current number of the variables referencing a counted object and be sure to be synchronized-with the last dec() operation (i.e. to see all the results of non-atomic memory changes happened-before the last dec() operation which should normally occurs when one of the variable of the counted object is destroyed on going out of its scope). Since only inc()/dec() operations are supposed to be normally used for changing the count value, it is considered to be an unusual case where using of set_value() function can be necessary.

inc() throws std::runtime_error if the current value to be incremented is 0 as this circumstance is considered as a variable of the counted object is being constructed/copied from a reference just becoming a dangling one.

Definition at line 229 of file utility.hpp.

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

• utility.hpp