[#BloombergLP-balb-PipeControlChannel]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/balb.adoc[balb]::PipeControlChannel
:relfileprefix: ../../
:mrdocs:

This class is a mechanism for reading control messages from a named pipe. Use `start` to spawn a thread that handles messages arriving at the pipe, and `shutdown` to stop reading. `stop` blocks until the processing thread has been terminated by a call to `shutdown` (either before `stop` is called, or from some other thread).

== Synopsis

Declared in `<balb_pipecontrolchannel.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
class PipeControlChannel;
----

== Type Aliases

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/balb/PipeControlChannel/ControlCallback.adoc[`ControlCallback`] 
| This type of function is called to handle control messages received on the pipe. The `message` is one complete message read from the pipe, without the terminating newline character.
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/balb/PipeControlChannel/2constructor-05.adoc[`PipeControlChannel`]         [.small]#[constructor]#
| Constructors
| xref:BloombergLP/balb/PipeControlChannel/2destructor.adoc[`~PipeControlChannel`] [.small]#[destructor]#
| Destroy this object. Shut down the processing thread if it is still running and block until it terminates. Close the named pipe and clean up any associated system resources.
| xref:BloombergLP/balb/PipeControlChannel/allocator.adoc[`allocator`] 
| Return the allocator used by this object to supply memory. Note that if no allocator was supplied at construction the default allocator in effect at construction is used.
| xref:BloombergLP/balb/PipeControlChannel/permissions.adoc[`permissions`] 
| Return the permission bit mask that will be applied to the named pipe on the next call to `start`.
| xref:BloombergLP/balb/PipeControlChannel/pipeName.adoc[`pipeName`] 
| Return the fully qualified system name of the pipe.
| xref:BloombergLP/balb/PipeControlChannel/setPermissions.adoc[`setPermissions`] 
| Set the permission bit mask for the underlying named pipe to the specified `permissions` value. The behavior is undefined unless `bdls::FilePermissions::isValidBaseBits(permissions)`. This setting only takes effect on the next call to `start`; calling this method has no effect on a pipe that has already been opened. See the class‐level documentation for a description of the cross‐platform semantics. The behavior is undefined if this method is called while the background thread is running (i.e., after `start` and before `shutdown`), or if the `permissions` value is not valid.
| xref:BloombergLP/balb/PipeControlChannel/shutdown.adoc[`shutdown`] 
| Stop reading from the pipe and dispatching messages. If the background thread has begun processing a message, this method will block until a message that is currently being processed completes.
| xref:BloombergLP/balb/PipeControlChannel/start-09.adoc[`start`] 
| `start` overloads
| xref:BloombergLP/balb/PipeControlChannel/stop.adoc[`stop`] 
| Block until the background thread has been terminated by a call to `shutdown`. Then close the pipe and clean up the associated file.
|===


== Static Data Members

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/balb/PipeControlChannel/k_DEFAULT_PERMISSIONS.adoc[`k_DEFAULT_PERMISSIONS`] 
| The default permission bit mask for the underlying named pipe (read/write for owner, group, and others).
|===



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