TimeStepBase_Tria< dim > Class Template Reference

#include <deal.II/numerics/time_dependent.h>

Inheritance diagram for TimeStepBase_Tria< dim >:

Public Types
enum	SolutionState { grid_refinement = 0x1000 }
using	Flags = typename TimeStepBase_Tria_Flags::Flags<dim>
using	RefinementFlags
using	RefinementData = typename TimeStepBase_Tria_Flags::RefinementData<dim>

Public Member Functions
	TimeStepBase_Tria ()
	TimeStepBase_Tria (const double time, const Triangulation< dim, dim > &coarse_grid, const Flags &flags, const RefinementFlags &refinement_flags=RefinementFlags())
virtual	~TimeStepBase_Tria () override
virtual void	wake_up (const unsigned int wakeup_level) override
virtual void	sleep (const unsigned int) override
void	refine_grid (const RefinementData data)
virtual void	init_for_refinement ()
virtual void	get_tria_refinement_criteria (Vector< float > &criteria) const =0
void	save_refine_flags ()
virtual std::size_t	memory_consumption () const override
virtual void	start_sweep ()
virtual void	end_sweep ()
virtual void	init_for_primal_problem ()
virtual void	init_for_dual_problem ()
virtual void	init_for_postprocessing ()
virtual void	solve_primal_problem ()=0
virtual void	solve_dual_problem ()
virtual void	postprocess_timestep ()
double	get_time () const
unsigned int	get_timestep_no () const
double	get_backward_timestep () const
double	get_forward_timestep () const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
Subscriptor functionality
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.
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

Static Public Member Functions
static ::ExceptionBase &	ExcGridNotDeleted ()
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Protected Attributes
SmartPointer< Triangulation< dim, dim >, TimeStepBase_Tria< dim > >	tria
SmartPointer< const Triangulation< dim, dim >, TimeStepBase_Tria< dim > >	coarse_grid
const Flags	flags
const RefinementFlags	refinement_flags
const TimeStepBase *	previous_timestep
const TimeStepBase *	next_timestep
unsigned int	sweep_no
unsigned int	timestep_no
const double	time
unsigned int	next_action

Private Types
using	map_value_type = decltype(counter_map)::value_type
using	map_iterator = decltype(counter_map)::iterator

Private Member Functions
void	restore_grid ()
void	set_previous_timestep (const TimeStepBase *previous)
void	set_next_timestep (const TimeStepBase *next)
void	set_timestep_no (const unsigned int step_no)
void	set_sweep_no (const unsigned int sweep_no)
void	check_no_subscribers () const noexcept

Private Attributes
std::vector< std::vector< bool > >	refine_flags
std::vector< std::vector< bool > >	coarsen_flags
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

Static Private Attributes
static std::mutex	mutex

Detailed Description

template<int dim>
class TimeStepBase_Tria< dim >

Specialization of TimeStepBase which addresses some aspects of grid handling. In particular, this class is thought to make handling of grids available that are adaptively refined on each time step separately or with a loose coupling between time steps. It also takes care of deleting and rebuilding grids when memory resources are a point, through the sleep and wake_up functions declared in the base class.

In addition to that, it offers functions which do some rather hairy refinement rules for time dependent problems, trying to avoid too much change in the grids between subsequent time levels, while also trying to retain the freedom of refining each grid separately. There are lots of flags and numbers controlling this function, which might drastically change the behavior of the function – see the description of the flags for further information.

Definition at line 1302 of file time_dependent.h.

Member Typedef Documentation

Flags

template<int dim>

using TimeStepBase_Tria< dim >::Flags = typename TimeStepBase_Tria_Flags::Flags<dim>

Typedef the data types of the TimeStepBase_Tria_Flags() namespace into local scope.

Definition at line 1309 of file time_dependent.h.

RefinementFlags

template<int dim>

using TimeStepBase_Tria< dim >::RefinementFlags

Initial value:

 
    typename TimeStepBase_Tria_Flags::RefinementFlags<dim>

Definition at line 1310 of file time_dependent.h.

RefinementData

template<int dim>

using TimeStepBase_Tria< dim >::RefinementData = typename TimeStepBase_Tria_Flags::RefinementData<dim>

Definition at line 1312 of file time_dependent.h.

map_value_type

using Subscriptor::map_value_type = decltype(counter_map)::value_type

privateinherited

The data type used in counter_map.

Definition at line 229 of file subscriptor.h.

map_iterator

using Subscriptor::map_iterator = decltype(counter_map)::iterator

privateinherited

The iterator type used in counter_map.

Definition at line 234 of file subscriptor.h.

Member Enumeration Documentation

SolutionState

template<int dim>

enum TimeStepBase_Tria::SolutionState

Extension of the enum in the base class denoting the next action to be done.

Enumerator
grid_refinement	Perform grid refinement next.

Definition at line 1319 of file time_dependent.h.

Constructor & Destructor Documentation

TimeStepBase_Tria() [1/2]

template<int dim>

TimeStepBase_Tria< dim >::TimeStepBase_Tria

(

)

Default constructor. Does nothing but throws an exception. We need to have such a constructor in order to satisfy the needs of derived classes, which take this class as a virtual base class and don't need to call this constructor of they are not terminal classes. The compiler would like to know a constructor to call anyway since it can't know that the class is not terminal.

Definition at line 422 of file time_dependent.cc.

TimeStepBase_Tria() [2/2]

template<int dim>

TimeStepBase_Tria< dim >::TimeStepBase_Tria	(	const double	time,
		const Triangulation< dim, dim > &	coarse_grid,
		const Flags &	flags,
		const RefinementFlags &	refinement_flags = RefinementFlags() )

Constructor. Takes a coarse grid from which the grids on this time level will be derived and some flags steering the behavior of this object.

The ownership of the coarse grid stays with the creator of this object. However, it is locked from destruction to guarantee the lifetime of the coarse grid is longer than it is needed by this object.

You need to give the general flags structure to this function since it is needed anyway; the refinement flags can be omitted if you do not intend to call the refinement function of this class.

~TimeStepBase_Tria()

template<int dim>

TimeStepBase_Tria< dim >::~TimeStepBase_Tria ( )

overridevirtual

Destructor. At present, this does not more than releasing the lock on the coarse grid triangulation given to the constructor.

Definition at line 452 of file time_dependent.cc.

Member Function Documentation

wake_up()

template<int dim>

void TimeStepBase_Tria< dim >::wake_up ( const unsigned int wakeup_level )

overridevirtual

Reconstruct all the data that is needed for this time level to work. This function serves to reget all the variables and data structures to work again after they have been send to sleep some time before, or at the first time we visit this time level. In particular, it is used to reconstruct the triangulation, degree of freedom handlers, to reload data vectors in case they have been stored to disk, etc. By default, this function rebuilds the triangulation if the respective flag has been set to destroy it in the sleep function. It does so also the first time we hit this function and wakeup_level equals flags.wakeup_level_to_build_grid, independently of the value of the mentioned flag. (Actually, it does so whenever the triangulation pointer equals the Null pointer and the value of wakeup_level is right.)

Since this is an important task, you should call this function from your own function, should you choose to overload it in your own class (which likely is the case), preferably at the beginning so that your function can take effect of the triangulation already existing.

Reimplemented from TimeStepBase.

Definition at line 470 of file time_dependent.cc.

sleep()

template<int dim>

void TimeStepBase_Tria< dim >::sleep ( const unsigned int sleep_level )

overridevirtual

This is the opposite function to wake_up. It is used to delete data or save it to disk after they are no more needed for the present sweep. Typical kinds of data for this are data vectors, degree of freedom handlers, triangulation objects, etc. which occupy large amounts of memory and may therefore be externalized.

By default, if the user specified so in the flags for this object, the triangulation is deleted and the refinement history is saved such that the respective wake_up function can rebuild it. You should therefore call this function from your overloaded version, preferably at the end so that your function can use the triangulation as long as you need it.

Reimplemented from TimeStepBase.

Definition at line 483 of file time_dependent.cc.

refine_grid()

template<int dim>

void TimeStepBase_Tria< dim >::refine_grid

(

const RefinementData

data

)

Do the refinement according to the flags passed to the constructor of this object and the data passed to this function. For a description of the working of this function refer to the general documentation of this class.

In fact, this function does not actually refine or coarsen the triangulation, but only sets the respective flags. This is done because usually you will not need the grid immediately afterwards but only in the next sweep, so it suffices to store the flags and rebuild it the next time we need it. Also, it may be that the next time step would like to add or delete some flags, so we have to wait anyway with the use of this grid.

Definition at line 736 of file time_dependent.cc.

init_for_refinement()

template<int dim>

void TimeStepBase_Tria< dim >::init_for_refinement ( )

virtual

Respective init function for the refinement loop; does nothing in the default implementation, apart from setting next_action to grid_refinement but can be overloaded.

Definition at line 1140 of file time_dependent.cc.

get_tria_refinement_criteria()

template<int dim>

virtual void TimeStepBase_Tria< dim >::get_tria_refinement_criteria ( Vector< float > & criteria ) const

pure virtual

Virtual function that should fill the vector with the refinement criteria for the present triangulation. It is used within the refine_grid function to get the criteria for the present time step, since they can't be passed through its argument when using the loop of the time step management object.

save_refine_flags()

template<int dim>

void TimeStepBase_Tria< dim >::save_refine_flags

(

)

The refinement flags of the triangulation are stored in a local variable thus allowing a restoration. The coarsening flags are also stored.

Definition at line 504 of file time_dependent.cc.

memory_consumption()

template<int dim>

std::size_t TimeStepBase_Tria< dim >::memory_consumption ( ) const

overridevirtual

Determine an estimate for the memory consumption (in bytes) of this object.

You will want to overload this function in derived classes to compute the amount memory used by the derived class, and add the result of this function to your result.

Reimplemented from TimeStepBase.

Definition at line 1149 of file time_dependent.cc.

restore_grid()

template<int dim>

void TimeStepBase_Tria< dim >::restore_grid ( )

private

Restore the grid according to the saved data. For this, the coarse grid is copied and the grid is stepwise rebuilt using the saved flags.

Definition at line 518 of file time_dependent.cc.

start_sweep()

void TimeStepBase::start_sweep ( )

virtualinherited

This function is called each time before a new sweep is started. You may want to set up some fields needed in the course of the computations, and so on. You should take good care, however, not to install large objects, which should be deferred until the wake_up function is called.

A typical action of this function would be sorting out names of temporary files needed in the process of solving, etc.

At the time this function is called, the values of timestep_no, sweep_no and the pointer to the previous and next time step object already have their correct value.

The default implementation of this function does nothing.

Definition at line 291 of file time_dependent.cc.

end_sweep()

void TimeStepBase::end_sweep ( )

virtualinherited

This is the analogous to the above function, but it is called at the end of a sweep. You will usually want to do clean-ups in this function, such as deleting temporary files and the like.

Definition at line 297 of file time_dependent.cc.

init_for_primal_problem()

void TimeStepBase::init_for_primal_problem ( )

virtualinherited

Before the primal problem is solved on each time level, this function is called (i.e. before the solution takes place on the first time level). By default, this function sets the next_action variable of this class. You may overload this function, but you should call this function within your own one.

Definition at line 303 of file time_dependent.cc.

init_for_dual_problem()

void TimeStepBase::init_for_dual_problem ( )

virtualinherited

Same as above, but called before a round of dual problem solves.

Definition at line 311 of file time_dependent.cc.

init_for_postprocessing()

void TimeStepBase::init_for_postprocessing ( )

virtualinherited

Same as above, but called before a round of postprocessing steps.

Definition at line 319 of file time_dependent.cc.

solve_primal_problem()

virtual void TimeStepBase::solve_primal_problem ( )

pure virtualinherited

This function is called by the manager object when solving the primal problem on this time level is needed. It is called after the wake_up function was called and before the sleep function will be called. There is no default implementation for obvious reasons, so you have to overload this function.

solve_dual_problem()

void TimeStepBase::solve_dual_problem ( )

virtualinherited

This function is called by the manager object when solving the dual problem on this time level is needed. It is called after the wake_up function was called and before the sleep function will be called. There is a default implementation doing plain nothing since some problems may not need solving a dual problem. However, it will abort the program when being called anyway, since then you should really overload the function.

Definition at line 327 of file time_dependent.cc.

postprocess_timestep()

void TimeStepBase::postprocess_timestep ( )

virtualinherited

This function is called by the manager object when postprocessing this time level is needed. It is called after the wake_up function was called and before the sleep function will be called. There is a default implementation doing plain nothing since some problems may not need doing a postprocess step, e.g. if everything was already done when solving the primal problem. However, it will abort the program when being called anyway, since then you should really overload the function.

Definition at line 335 of file time_dependent.cc.

get_time()

double TimeStepBase::get_time ( ) const

inherited

Return the time value of this time step.

Definition at line 343 of file time_dependent.cc.

get_timestep_no()

unsigned int TimeStepBase::get_timestep_no ( ) const

inherited

Return the number of this time step. Note that this number may vary between different sweeps, if timesteps are added or deleted.

Definition at line 351 of file time_dependent.cc.

get_backward_timestep()

double TimeStepBase::get_backward_timestep ( ) const

inherited

Compute the time difference to the last time step. If this timestep is the first one, this function will result in an exception. Though this behavior seems a bit drastic, it is appropriate in most cases since if there is no previous time step you will need special treatment anyway and this way no invalid value is returned which could lead to wrong but unnoticed results of your computation. (The only sensible value to return in that case would not be zero, since valid computation can be done with that, but would be a denormalized value such as NaN. However, there is not much difference in finding that the results of a computation are all denormalized values or in getting an exception; in the latter case you at least get the exact place where your problem lies.)

Definition at line 359 of file time_dependent.cc.

get_forward_timestep()

double TimeStepBase::get_forward_timestep ( ) const

inherited

Return the time difference to the next time step. With regard to the case that there is no next time step, the same applies as for the function above.

Definition at line 370 of file time_dependent.cc.

set_previous_timestep()

void TimeStepBase::set_previous_timestep ( const TimeStepBase * previous )

privateinherited

Reset the pointer to the previous time step; shall only be called by the time level manager object.

This function is called at the set-up of the manager object and whenever a timestep is inserted or deleted.

Definition at line 381 of file time_dependent.cc.

set_next_timestep()

void TimeStepBase::set_next_timestep ( const TimeStepBase * next )

privateinherited

Reset the pointer to the next time step; shall only be called by the time level manager object.

This function is called at the set-up of the manager object and whenever a timestep is inserted or deleted.

Definition at line 389 of file time_dependent.cc.

set_timestep_no()

void TimeStepBase::set_timestep_no ( const unsigned int step_no )

privateinherited

Set the number this time step has in the list of timesteps. This function is called by the time step management object at the beginning of each sweep, to update information which may have changed due to addition or deletion of time levels.

Definition at line 397 of file time_dependent.cc.

set_sweep_no()

void TimeStepBase::set_sweep_no ( const unsigned int sweep_no )

privateinherited

Set the number of the sweep we are presently in. This function is called by the time level management object at start-up time of each sweep.

Definition at line 405 of file time_dependent.cc.

subscribe()

void Subscriptor::subscribe ( std::atomic< bool > *const validity, const std::string & identifier = "" ) const

inherited

Subscribes a user of the object by storing the pointer validity. The subscriber may be identified by text supplied as identifier.

Definition at line 135 of file subscriptor.cc.

unsubscribe()

void Subscriptor::unsubscribe ( std::atomic< bool > *const validity, const std::string & identifier = "" ) const

inherited

Unsubscribes a user from the object.

Note

The identifier and the validity pointer must be the same as the one supplied to subscribe().

Definition at line 155 of file subscriptor.cc.

n_subscriptions()

unsigned int Subscriptor::n_subscriptions ( ) const

inlineinherited

Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.

Definition at line 300 of file subscriptor.h.

list_subscribers() [1/2]

template<typename StreamType >

void Subscriptor::list_subscribers ( StreamType & stream ) const

inlineinherited

List the subscribers to the input stream.

Definition at line 317 of file subscriptor.h.

list_subscribers() [2/2]

void Subscriptor::list_subscribers ( ) const

inherited

List the subscribers to deallog.

Definition at line 203 of file subscriptor.cc.

serialize()

template<class Archive >

void Subscriptor::serialize ( Archive & ar, const unsigned int version )

inlineinherited

Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.

This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.

Definition at line 309 of file subscriptor.h.

check_no_subscribers()

void Subscriptor::check_no_subscribers ( ) const

privatenoexceptinherited

Check that there are no objects subscribing to this object. If this check passes then it is safe to destroy the current object. It this check fails then this function will either abort or print an error message to deallog (by using the AssertNothrow mechanism), but will not throw an exception.

Note

Since this function is just a consistency check it does nothing in release mode.

If this function is called when there is an uncaught exception then, rather than aborting, this function prints an error message to the standard error stream and returns.

Definition at line 52 of file subscriptor.cc.

Member Data Documentation

tria

template<int dim>

SmartPointer<Triangulation<dim, dim>, TimeStepBase_Tria<dim> > TimeStepBase_Tria< dim >::tria

protected

Triangulation used at this time level. Since this is something that every time stepping scheme needs to have, we can safely put it into the base class. Note that the triangulation is frequently deleted and rebuilt by the functions sleep and wake_up to save memory, if such a behavior is specified in the flags structure.

Definition at line 1469 of file time_dependent.h.

coarse_grid

template<int dim>

SmartPointer<const Triangulation<dim, dim>, TimeStepBase_Tria<dim> > TimeStepBase_Tria< dim >::coarse_grid

protected

Pointer to a grid which is to be used as the coarse grid for this time level. This pointer is set through the constructor; ownership remains with the owner of this management object.

Definition at line 1477 of file time_dependent.h.

flags

template<int dim>

const Flags TimeStepBase_Tria< dim >::flags

protected

Some flags about how this time level shall behave. See the documentation of this struct to find out more about that.

Definition at line 1483 of file time_dependent.h.

refinement_flags

template<int dim>

const RefinementFlags TimeStepBase_Tria< dim >::refinement_flags

protected

Flags controlling the refinement process; see the documentation of the respective structure for more information.

Definition at line 1489 of file time_dependent.h.

refine_flags

template<int dim>

std::vector<std::vector<bool> > TimeStepBase_Tria< dim >::refine_flags

private

Vectors holding the refinement and coarsening flags of the different sweeps on this time level. The vectors therefore hold the history of the grid.

Definition at line 1497 of file time_dependent.h.

coarsen_flags

template<int dim>

std::vector<std::vector<bool> > TimeStepBase_Tria< dim >::coarsen_flags

private

refine_flags

Definition at line 1502 of file time_dependent.h.

previous_timestep

const TimeStepBase* TimeStepBase::previous_timestep

protectedinherited

Pointer to the previous time step object in the list.

Definition at line 872 of file time_dependent.h.

next_timestep

const TimeStepBase* TimeStepBase::next_timestep

protectedinherited

Pointer to the next time step object in the list.

Definition at line 877 of file time_dependent.h.

sweep_no

unsigned int TimeStepBase::sweep_no

protectedinherited

Number of the sweep we are presently in. This number is reset by the time level manager before a sweep is started.

Definition at line 883 of file time_dependent.h.

timestep_no

unsigned int TimeStepBase::timestep_no

protectedinherited

Number of the time step, counted from zero onwards. This number is reset at the start of each sweep by the time level manager, since some time steps may have been inserted or deleted after the previous sweep.

Definition at line 890 of file time_dependent.h.

time

const double TimeStepBase::time

protectedinherited

Discrete time this level operates on.

Definition at line 895 of file time_dependent.h.

next_action

unsigned int TimeStepBase::next_action

protectedinherited

Variable storing whether the solution of a primal or a dual problem is actual, or any of the other actions specified. This variable is set by the init_for_* functions.

Definition at line 902 of file time_dependent.h.

counter

std::atomic<unsigned int> Subscriptor::counter

mutableprivateinherited

Store the number of objects which subscribed to this object. Initially, this number is zero, and upon destruction it shall be zero again (i.e. all objects which subscribed should have unsubscribed again).

The creator (and owner) of an object is counted in the map below if HE manages to supply identification.

We use the mutable keyword in order to allow subscription to constant objects also.

This counter may be read from and written to concurrently in multithreaded code: hence we use the std::atomic class template.

Definition at line 218 of file subscriptor.h.

counter_map

std::map<std::string, unsigned int> Subscriptor::counter_map

mutableprivateinherited

In this map, we count subscriptions for each different identification string supplied to subscribe().

Definition at line 224 of file subscriptor.h.

validity_pointers

std::vector<std::atomic<bool> *> Subscriptor::validity_pointers

mutableprivateinherited

In this vector, we store pointers to the validity bool in the SmartPointer objects that subscribe to this class.

Definition at line 240 of file subscriptor.h.

object_info

const std::type_info* Subscriptor::object_info

mutableprivateinherited

Pointer to the typeinfo object of this object, from which we can later deduce the class name. Since this information on the derived class is neither available in the destructor, nor in the constructor, we obtain it in between and store it here.

Definition at line 248 of file subscriptor.h.

mutex

std::mutex Subscriptor::mutex

staticprivateinherited

A mutex used to ensure data consistency when accessing the mutable members of this class. This lock is used in the subscribe() and unsubscribe() functions, as well as in list_subscribers().

Definition at line 271 of file subscriptor.h.

---

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

• include/deal.II/numerics/time_dependent.h
• source/numerics/time_dependent.cc