[#BloombergLP-bslstl-StopToken_RefCountedState]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslstl.adoc[bslstl]::StopToken&lowbar;RefCountedState
:relfileprefix: ../../
:mrdocs:

This component&hyphen;private struct adds a reference count to the internal `StopState` class&period; This reference count represents the number of `bsl&colon;&colon;stop&lowbar;source` objects that refer to the stop state (NOT the total number of objects that refer to the stop state)&period;

== Synopsis

Declared in `&lt;bslstl&lowbar;stoptoken&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
struct StopToken&lowbar;RefCountedState
    : xref:BloombergLP/bslstl/StopState.adoc[StopState]
----

== Description

Implementation note&colon; The reference count has been kept outside the `StopState` object in order to enable `StopState` to potentially be reused to implement `in&lowbar;place&lowbar;stop&lowbar;source` (from WG21 proposal P2300R7) without the overhead from the reference count&period;

== Base Classes

[cols="1,4"]
|===
| Name| Description
| `xref:BloombergLP/bslstl/StopState.adoc[StopState]`
| Shared stop state that tracks a stop request and registered callbacks&period;
|===

== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bslstl/StopState/deregister.adoc[`deregister`] 
| If the callback of the specified `node` is currently executing, wait for it to complete&period; Otherwise, remove `node` from the list of nodes registered to this state&period; The behavior is undefined if this method is called more than once for a given `node` or if `node` was not previously registered to this state by a call to `enregister` that returned `true`&period;
| xref:BloombergLP/bslstl/StopState/enregister.adoc[`enregister`] 
| If a stop has already been requested, then invoke the callback of the specified `node` and return `false`&period; Otherwise, add `node` to the list of nodes registered to this state and return `true`&period; The behavior is undefined if this method is called more than once for a given `node`&period;
| xref:BloombergLP/bslstl/StopState/requestStop.adoc[`requestStop`] 
| If this `StopState` object has already had a stop requested, return `false`&period; Otherwise, atomically mark this `StopState` object as having had a stop requested, then execute all registered callbacks in an unspecified order, and finally return `true`&period;
| xref:BloombergLP/bslstl/StopState/stopRequested.adoc[`stopRequested`] 
| Return `true` if a stop has been requested on this `StopState` object, and `false` otherwise&period;
|===


== Data Members

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bslstl/StopToken_RefCountedState/d_stopSourceCount.adoc[`d&lowbar;stopSourceCount`] 
| The number of `bsl&colon;&colon;stop&lowbar;source` objects that refer to this stop state&period;
|===



[.small]#Created with https://www.mrdocs.com[MrDocs]#
