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| virtual | ~TraversalObserver () |
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| virtual void | loadCell (const GridTraversalEvent &event)=0 |
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| virtual void | enterCell (const GridTraversalEvent &event)=0 |
| | Event is invoked per cell.
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| virtual void | leaveCell (const GridTraversalEvent &event)=0 |
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| virtual void | storeCell (const GridTraversalEvent &event)=0 |
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| virtual TraversalObserver * | clone (int spacetreeId)=0 |
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| virtual std::vector< GridControlEvent > | getGridControlEvents () const =0 |
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| virtual void | beginTraversal (const tarch::la::Vector< Dimensions, double > &x, const tarch::la::Vector< Dimensions, double > &h)=0 |
| | Begin the traversal.
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| virtual void | endTraversal (const tarch::la::Vector< Dimensions, double > &x, const tarch::la::Vector< Dimensions, double > &h)=0 |
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| virtual void | exchangeAllVerticalDataExchangeStacks (int) |
| | Send local data from top level of local mesh to master and receive its top-down information in return.
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| virtual void | exchangeAllHorizontalDataExchangeStacks (bool) |
| | Exchange all the data along the domain boundaries.
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| virtual void | exchangeAllPeriodicBoundaryDataStacks () |
| | Exchange all periodic boundary data.
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| virtual void | streamDataFromSplittingTreeToNewTree (int) |
| | Stream data from current tree on which this routine is called to the new worker.
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| virtual void | streamDataFromJoiningTreeToMasterTree (int) |
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| virtual void | finishAllOutstandingSendsAndReceives () |
| | Wrap up all sends and receives, i.e.
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| virtual void | sendVertex (int, int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | sendFace (int, int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | sendCell (int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | receiveAndMergeVertex (int, int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | receiveAndMergeFace (int, int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | receiveAndMergeCell (int, SendReceiveContext, const GridTraversalEvent &) |
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| virtual void | deleteAllStacks () |
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behaviour
There is one observer by grid traversal thread and per rank. The observers are generated from the original observer via the clone() operator. Therefore, you never should be required to write a copy constructor. If you run without multithreading but with MPI, you still have to use a SpacetreeSet. The code therefore continues to copy observers.
Definition at line 36 of file TraversalObserver.h.
There are three different scenarios when we merge data:
- We exchange data as we are at a proper parallel boundary. As we work with a non-overlapping domain decomposition and handle the individual levels separately, this can only happen for vertices and faces. It never happens for cells.
- We exchange data as we are at a periodic boundary. Again, this happens only for vertices and faces.
- We exchange data between different levels of the tree, where the parent cell is hosted on another tree than the child. In this case, we also exchange cell data.
There are two more modes: join and fork. It is important to note that these differ from the aforementioned modi, as forks and joins are realised as copies. We do not merge existing data structures, but we copy them. As such, the context fork and the context join do arise when we discuss data exchange. They do never arise when we speak about data merges. If you have a case distinction within a merge, those two modi should be left out (or equipped with assertion). They should be never entered.
| Enumerator |
|---|
| BoundaryExchange | |
| MultiscaleExchange | |
| ForkDomain | |
| JoinDomain | |
| PeriodicBoundaryDataSwap | |
Definition at line 231 of file TraversalObserver.h.
| virtual TraversalObserver * peano4::grid::TraversalObserver::clone |
( |
int | spacetreeId | ) |
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pure virtual |
I use the clone to create one observer object per traversal thread. So
between different spacetrees of one spacetree set, there can be no race
condition. Yet, the clone() itself could be called in parallel.
\section Global per-sweep actions
If you want to implement an operation once per sweep in a parallel
environment, then you can exploit the fact that the spacetree set also
creates an observer for the global master thread, i.e. tree no 0. So if
you add a statement alike
<pre>
if (peano4::parallel::Node::isGlobalMaster(spacetreeId)) { ... }
then you can be sure that the branch body is executed only once globally per grid sweep.
The counterpart of the clone operation is the destructor.
Implemented in examples::grid::MyObserver, examples::regulargridupscaling::MyObserver, peano4::grid::EmptyTraversalObserver, and peano4::grid::TraversalVTKPlotter.
| virtual void peano4::grid::TraversalObserver::exchangeAllHorizontalDataExchangeStacks |
( |
bool | | ) |
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virtual |
Exchange all the data along the domain boundaries.
If the bool is set, we do send out exactly as many elements per face or vertex as we expect to receive. Therefore, the boundary exchange can optimise the data exchange.
The SpacetreeSet class provides some generic routines for this that you can use. Simply invoke them for every data container that you use. If you trigger non-blocking MPI, you don't have to wait until they are finished. You can expect the calling routine that it calls finishAllOutstandingSendsAndReceives() later on.
Definition at line 178 of file TraversalObserver.h.
| virtual void peano4::grid::TraversalObserver::exchangeAllVerticalDataExchangeStacks |
( |
int | | ) |
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virtual |
Send local data from top level of local mesh to master and receive its top-down information in return.
The SpacetreeSet class provides some generic routines for this that you can use. Simply invoke them for every data container that you use. If you trigger non-blocking MPI, you don't have to wait until they are finished. You can expect the calling routine that it calls finishAllOutstandingSendsAndReceives() later on.
Definition at line 164 of file TraversalObserver.h.
| virtual std::vector< GridControlEvent > peano4::grid::TraversalObserver::getGridControlEvents |
( |
| ) |
const |
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pure virtual |
The tree traversal invokes this operation before beginIteration.
\section Content
Dynamic AMR is controlled via a sequence of grid control events. Each event spans a certain region and prescribes an h resolution over this region. Depending on the type of the event (erase or refine), the grid adopts. A simple snippet just creating a refined area in a square is
std::vector< peano4::grid::GridControlEvent > applications4::grid::MyObserver::getGridControlEvents() {
std::vector< peano4::grid::GridControlEvent > controlEvents;
peano4::grid::GridControlEvent newEvent;
newEvent.setRefinementControl( peano4::grid::GridControlEvent::RefinementControl::Refine );
newEvent.setOffset( {0.0,0.0} );
newEvent.setWidth( {0.5,0.5} );
newEvent.setH( {0.05,0.05} );
controlEvents.push_back(newEvent);
return controlEvents;
}
The entries are logically ordered. The later the entry, the more important it is. So entry 2 overrules entry 1.
Implemented in peano4::grid::EmptyTraversalObserver, and peano4::grid::TraversalVTKPlotter.
| virtual void peano4::grid::TraversalObserver::streamDataFromSplittingTreeToNewTree |
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int | | ) |
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virtual |
Stream data from current tree on which this routine is called to the new worker.
The SpacetreeSet class provides some generic routines for this that you can use. Simply invoke them for every data container that you use. If you trigger non-blocking MPI, you don't have to wait until they are finished. You can expect the calling routine that it calls finishAllOutstandingSendsAndReceives() later on.
Definition at line 199 of file TraversalObserver.h.
| constexpr int peano4::grid::TraversalObserver::NoData = -1 |
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staticconstexpr |
Can this grid entity hold data.
I use this one to indicate that no data is associated with a grid entity, as the grid entity is outside of the local computational domain. The term refers explicitly to the domain decomposition, i.e. this value is used to flag grid entities which are there in the tree, as we always have to work with full trees, but that cannot really hold any data as the user never sees them.
Definition at line 52 of file TraversalObserver.h.
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