smtk::resource::GarbageCollector Class Reference

A class that owns ephemeral objects and remove them when abandoned. More...

#include <GarbageCollector.h>

Inheritance diagram for smtk::resource::GarbageCollector:

Collaboration diagram for smtk::resource::GarbageCollector:

Public Types
using	WeakManagerPtr = smtk::operation::WeakManagerPtr
using	Key = smtk::operation::Observers::Key
using	ObserverMap = std::map< WeakManagerPtr, Key, std::owner_less< WeakManagerPtr > >

Public Member Functions
	smtkTypeMacroBase (smtk::resource::GarbageCollector)
	smtkCreateMacro (smtk::resource::GarbageCollector)
	GarbageCollector (const GarbageCollector &)=delete
GarbageCollector &	operator= (const GarbageCollector &)=delete
bool	add (const smtk::operation::OperationPtr &deleter)
	Queue an operation to clean up an ephemeral resource.

Protected Types
enum	Status { Invalid = 0, NotReady = 1, Ready = 2 }

Protected Member Functions
int	collectGarbage (const smtk::operation::Operation &, smtk::operation::EventType, smtk::operation::Operation::Result)

Static Protected Member Functions
static Status	checkOperation (const smtk::operation::Operation *op)
	Returns true if the operation is ready to be evaluated, false otherwise.

Protected Attributes
std::set< smtk::operation::OperationPtr >	m_garbage
	The set of operations used to collect garbage (and whose associations indicate which objects are garbage).
ObserverMap	m_observers
	The "ids" of observers calling collectGarbage after each operation.

Detailed Description

A class that owns ephemeral objects and remove them when abandoned.

This class will queue an operation (which you provide) to delete the ephemeral objects associated with the operation when their shared-pointer use-count drops to 1 (indicating they are owned solely by the resource managing them).

Note that your deletion operation must (a) accept associations, (b) prevent its associations from holding references (i.e., "HoldReferences"="false"), and (c) require at least 1 associated persistent object.

This class works by adding an observer to the registered operation manager and iterating over its set of delete-operations' associations when any operation completes successfully.

Note that an operation, A, passed to the garbage collector is not guaranteed to run; some other operation, B, may delete the associated objects first. In that case, when B completes successfully, the garbage collector will run, see that A has no valid associated objects (since they are weak references to the deleted object), and remove operation A from its list of collectors. It is also possible A will never be invoked because the program exits while holding references.

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

• /home/docs/checkouts/readthedocs.org/user_builds/smtk/checkouts/latest/smtk/resource/GarbageCollector.h
• /home/docs/checkouts/readthedocs.org/user_builds/smtk/checkouts/latest/smtk/resource/GarbageCollector.cxx