GrowingVectorMemory< VectorType > Class Template Reference

#include <deal.II/lac/vector_memory.h>

Inheritance diagram for GrowingVectorMemory< VectorType >:

Classes
struct	Pool

Public Types
using	size_type = types::global_dof_index

Public Member Functions
	GrowingVectorMemory (const size_type initial_size=0, const bool log_statistics=false)
virtual	~GrowingVectorMemory () override
virtual VectorType *	alloc () override
virtual void	free (const VectorType *const) override
virtual std::size_t	memory_consumption () const
virtual void	free (const ::Vector< double > *const)=0

Static Public Member Functions
static void	release_unused_memory ()
static ::ExceptionBase &	ExcNotAllocatedHere ()

Private Types
using	entry_type = std::pair< bool, std::unique_ptr< VectorType > >

Static Private Member Functions
static Pool &	get_pool ()

Private Attributes
size_type	total_alloc
size_type	current_alloc
bool	log_statistics

Static Private Attributes
static Threads::Mutex	mutex

Subscriptor functionality
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.
using	map_value_type = decltype(counter_map)::value_type
using	map_iterator = decltype(counter_map)::iterator
std::atomic< unsigned int >	counter
std::map< std::string, unsigned int >	counter_map
std::vector< std::atomic< bool > * >	validity_pointers
const std::type_info *	object_info
void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
unsigned int	n_subscriptions () const
template<typename StreamType >
void	list_subscribers (StreamType &stream) const
void	list_subscribers () const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)
void	check_no_subscribers () const noexcept

Detailed Description

template<typename VectorType = ::Vector<double>>
class GrowingVectorMemory< VectorType >

A pool based memory management class. See the documentation of the base class for a description of its purpose.

Each time a vector is requested from this class, it checks if it has one available and returns its address, or allocates a new one on the heap. If a vector is returned from its user, through the GrowingVectorMemory::free() member function, it doesn't return the allocated memory to the operating system memory subsystem, but keeps it around unused for later use if GrowingVectorMemory::alloc() is called again. The class therefore avoid the overhead of repeatedly allocating memory on the heap if temporary vectors are required and released frequently; on the other hand, it doesn't release once-allocated memory at the earliest possible time and may therefore lead to an increased overall memory consumption.

All GrowingVectorMemory objects of the same vector type use the same memory pool. (In other words: The pool of vectors from which this class draws is global, rather than a regular member variable of the current class that is destroyed at the time that the surrounding GrowingVectorMemory object is destroyed.) Therefore, functions can create such a GrowingVectorMemory object whenever needed without the performance penalty of creating a new memory pool every time. A drawback of this policy is that vectors once allocated are only released at the end of the program run.

Definition at line 313 of file vector_memory.h.

Member Function Documentation

free()

virtual void VectorMemory< ::Vector< double > >::free ( const ::Vector< double > * const  )

pure virtualinherited

Return a vector and indicate that it is not going to be used any further by the place that called alloc() to get a pointer to it.

Warning

Just like using new and delete explicitly in code invites bugs where memory is leaked (either because the corresponding delete is forgotten altogether, or because of exception safety issues), using the alloc() and free() functions explicitly invites writing code that accidentally leaks memory. You should consider using the VectorMemory::Pointer class instead, which provides the same kind of service that std::unique provides for arbitrary memory allocated on the heap.

ExcNotAllocatedHere()

static ::ExceptionBase & VectorMemory< ::Vector< double > >::ExcNotAllocatedHere ( )

staticinherited

Vector was not allocated from this memory pool.

Note

The message that will be printed by this exception reads:

"You are trying to deallocate a vector from a memory pool, but this " "vector has not actually been allocated by the same pool before."

---

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

• include/deal.II/lac/vector_memory.h