Dune::Communication< MPI_Comm > Class Reference

Specialization of Communication for MPI. More...

#include <dune/common/parallel/mpicommunication.hh>

Public Member Functions
	Communication (const MPI_Comm &c=MPI_COMM_WORLD)
	Instantiation using a MPI communicator.
	Communication (const Communication< No_Comm > &)
	Converting constructor for no-communication that is interpreted as MPI_COMM_SELF.
int	rank () const
	Return rank, is between 0 and size()-1. More...
int	size () const
	Number of processes in set, is greater than 0. More...
template<class T >
int	send (const T &data, int dest_rank, int tag) const
	Sends the data to the dest_rank. More...
template<class T >
MPIFuture< T >	isend (T &&data, int dest_rank, int tag) const
	Sends the data to the dest_rank nonblocking. More...
template<class T >
T	recv (T &&data, int source_rank, int tag, MPI_Status *status=MPI_STATUS_IGNORE) const
	Receives the data from the source_rank. More...
template<class T >
MPIFuture< T >	irecv (T &&data, int source_rank, int tag) const
	Receives the data from the source_rank nonblocking. More...
template<typename T >
T	sum (const T &in) const
	Compute the sum of the argument over all processes and return the result in every process. Assumes that T has an operator+. More...
template<typename T >
int	sum (T *inout, int len) const
	Compute the sum of the argument over all processes and return the result in every process. Assumes that T has an operator+. More...
template<typename T >
T	prod (const T &in) const
	Compute the product of the argument over all processes and return the result in every process. Assumes that T has an operator*. More...
template<typename T >
int	prod (T *inout, int len) const
	Compute the product of the argument over all processes and return the result in every process. Assumes that T has an operator*. More...
template<typename T >
T	min (const T &in) const
	Compute the minimum of the argument over all processes and return the result in every process. Assumes that T has an operator<. More...
template<typename T >
int	min (T *inout, int len) const
	Compute the minimum of the argument over all processes and return the result in every process. Assumes that T has an operator<. More...
template<typename T >
T	max (const T &in) const
	Compute the maximum of the argument over all processes and return the result in every process. Assumes that T has an operator<. More...
template<typename T >
int	max (T *inout, int len) const
	Compute the maximum of the argument over all processes and return the result in every process. Assumes that T has an operator<. More...
int	barrier () const
	Wait until all processes have arrived at this point in the program. More...
MPIFuture< void >	ibarrier () const
	Nonblocking barrier. More...
template<typename T >
int	broadcast (T *inout, int len, int root) const
	Distribute an array from the process with rank root to all other processes. More...
template<class T >
MPIFuture< T >	ibroadcast (T &&data, int root) const
	Distribute an array from the process with rank root to all other processes nonblocking. More...
template<typename T >
int	gather (const T *in, T *out, int len, int root) const
	Gather arrays on root task. More...
template<class TIN , class TOUT = std::vector<TIN>>
MPIFuture< TOUT, TIN >	igather (TIN &&data_in, TOUT &&data_out, int root) const
	Gather arrays on root task nonblocking. More...
template<typename T >
int	gatherv (const T *in, int sendDataLen, T *out, int *recvDataLen, int *displ, int root) const
	Gather arrays of variable size on root task. More...
template<typename T >
int	scatter (const T *sendData, T *recvData, int len, int root) const
	Scatter array from a root to all other task. More...
template<class TIN , class TOUT = TIN>
MPIFuture< TOUT, TIN >	iscatter (TIN &&data_in, TOUT &&data_out, int root) const
	Scatter array from a root to all other task nonblocking. More...
template<typename T >
int	scatterv (const T *sendData, int *sendDataLen, int *displ, T *recvData, int recvDataLen, int root) const
	Scatter arrays of variable length from a root to all other tasks. More...
template<typename T , typename T1 >
int	allgather (const T *sbuf, int count, T1 *rbuf) const
	Gathers data from all tasks and distribute it to all. More...
template<class TIN , class TOUT = TIN>
MPIFuture< TOUT, TIN >	iallgather (TIN &&data_in, TOUT &&data_out) const
	Gathers data from all tasks and distribute it to all nonblocking. More...
template<typename T >
int	allgatherv (const T *in, int sendDataLen, T *out, int *recvDataLen, int *displ) const
	Gathers data of variable length from all tasks and distribute it to all. More...
template<typename BinaryFunction , typename Type >
int	allreduce (Type *inout, int len) const
	Compute something over all processes for each component of an array and return the result in every process. More...
template<class BinaryFunction , class TIN , class TOUT = TIN>
MPIFuture< TOUT, TIN >	iallreduce (TIN &&data_in, TOUT &&data_out) const
	Compute something over all processes nonblocking. More...
template<class BinaryFunction , class T >
MPIFuture< T >	iallreduce (T &&data) const
	Compute something over all processes nonblocking. More...
template<typename BinaryFunction , typename Type >
int	allreduce (const Type *in, Type *out, int len) const

Detailed Description

Specialization of Communication for MPI.

Member Function Documentation

allgather()

template<typename T , typename T1 >

int Dune::Communication< MPI_Comm >::allgather ( const T *  sbuf, int  count, T1 *  rbuf  ) const

inline

Gathers data from all tasks and distribute it to all.

The block of data sent from the jth process is received by every process and placed in the jth block of the buffer recvbuf.

Parameters

[in]	sbuf	The buffer with the data to send. Has to be the same for each task.
[in]	count	The number of elements to send by any process.
[out]	rbuf	The receive buffer for the data. Has to be of size notasks*count, with notasks being the number of tasks in the communicator.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

allgatherv()

template<typename T >

int Dune::Communication< MPI_Comm >::allgatherv ( const T *  in, int  sendDataLen, T *  out, int *  recvDataLen, int *  displ  ) const

inline

Gathers data of variable length from all tasks and distribute it to all.

The block of data sent from the jth process is received by every process and placed in the jth block of the buffer out.

Parameters

[in]	in	The send buffer with the data to send.
[in]	sendDataLen	The number of elements to send on each task.
[out]	out	The buffer to store the received data in.
[in]	recvDataLen	An array with size equal to the number of processes containing the number of elements to receive from process i at position i, i.e. the number that is passed as sendDataLen argument to this function in process i.
[in]	displ	An array with size equal to the number of processes. Data received from process i will be written starting at out+displ[i].

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

allreduce() [1/2]

template<typename BinaryFunction , typename Type >

int Dune::Communication< MPI_Comm >::allreduce ( const Type *  in, Type *  out, int  len  ) const

inline

allreduce() [2/2]

template<typename BinaryFunction , typename Type >

int Dune::Communication< MPI_Comm >::allreduce ( Type *  inout, int  len  ) const

inline

Compute something over all processes for each component of an array and return the result in every process.

The template parameter BinaryFunction is the type of the binary function to use for the computation

Parameters

inout	The array to compute on.
len	The number of components in the array

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

barrier()

int Dune::Communication< MPI_Comm >::barrier ( ) const

inline

Wait until all processes have arrived at this point in the program.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

Referenced by Dune::graphRepartition().

broadcast()

template<typename T >

int Dune::Communication< MPI_Comm >::broadcast ( T *  inout, int  len, int  root  ) const

inline

Distribute an array from the process with rank root to all other processes.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

gather()

template<typename T >

int Dune::Communication< MPI_Comm >::gather ( const T *  in, T *  out, int  len, int  root  ) const

inline

Gather arrays on root task.

Each process sends its in array of length len to the root process (including the root itself). In the root process these arrays are stored in rank order in the out array which must have size len * number of processes.

Parameters

[in]	in	The send buffer with the data to send.
[out]	out	The buffer to store the received data in. Might have length zero on non-root tasks.
[in]	len	The number of elements to send on each task.
[in]	root	The root task that gathers the data.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

Note

out must have space for P*len elements

gatherv()

template<typename T >

int Dune::Communication< MPI_Comm >::gatherv ( const T *  in, int  sendDataLen, T *  out, int *  recvDataLen, int *  displ, int  root  ) const

inline

Gather arrays of variable size on root task.

Each process sends its in array of length sendDataLen to the root process (including the root itself). In the root process these arrays are stored in rank order in the out array.

Parameters

[in]	in	The send buffer with the data to be sent
[in]	sendDataLen	The number of elements to send on each task
[out]	out	The buffer to store the received data in. May have length zero on non-root tasks.
[in]	recvDataLen	An array with size equal to the number of processes containing the number of elements to receive from process i at position i, i.e. the number that is passed as sendDataLen argument to this function in process i. May have length zero on non-root tasks.
[out]	displ	An array with size equal to the number of processes. Data received from process i will be written starting at out+displ[i] on the root process. May have length zero on non-root tasks.
[in]	root	The root task that gathers the data.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

iallgather()

template<class TIN , class TOUT = TIN>

MPIFuture< TOUT, TIN > Dune::Communication< MPI_Comm >::iallgather ( TIN &&  data_in, TOUT &&  data_out  ) const

inline

Gathers data from all tasks and distribute it to all nonblocking.

Returns

Future<TOUT, TIN> containing the distributed data

iallreduce() [1/2]

template<class BinaryFunction , class T >

MPIFuture< T > Dune::Communication< MPI_Comm >::iallreduce ( T &&  data ) const

inline

Compute something over all processes nonblocking.

Returns

Future<TOUT, TIN> containing the computed something

iallreduce() [2/2]

template<class BinaryFunction , class TIN , class TOUT = TIN>

MPIFuture< TOUT, TIN > Dune::Communication< MPI_Comm >::iallreduce ( TIN &&  data_in, TOUT &&  data_out  ) const

inline

Compute something over all processes nonblocking.

Returns

Future<TOUT, TIN> containing the computed something

ibarrier()

MPIFuture< void > Dune::Communication< MPI_Comm >::ibarrier ( ) const

inline

Nonblocking barrier.

Returns

Future<void> which is complete when all processes have reached the barrier

ibroadcast()

template<class T >

MPIFuture< T > Dune::Communication< MPI_Comm >::ibroadcast ( T &&  data, int  root  ) const

inline

Distribute an array from the process with rank root to all other processes nonblocking.

Returns

Future<T> containing the distributed data

igather()

template<class TIN , class TOUT = std::vector<TIN>>

MPIFuture< TOUT, TIN > Dune::Communication< MPI_Comm >::igather ( TIN &&  data_in, TOUT &&  data_out, int  root  ) const

inline

Gather arrays on root task nonblocking.

Returns

Future<TOUT, TIN> containing the gathered data

irecv()

template<class T >

MPIFuture< T > Dune::Communication< MPI_Comm >::irecv ( T &&  data, int  source_rank, int  tag  ) const

inline

Receives the data from the source_rank nonblocking.

Returns

Future<T> containing the received data when complete

References DUNE_THROW.

iscatter()

template<class TIN , class TOUT = TIN>

MPIFuture< TOUT, TIN > Dune::Communication< MPI_Comm >::iscatter ( TIN &&  data_in, TOUT &&  data_out, int  root  ) const

inline

Scatter array from a root to all other task nonblocking.

Returns

Future<TOUT, TIN> containing scattered data;

isend()

template<class T >

MPIFuture< T > Dune::Communication< MPI_Comm >::isend ( T &&  data, int  dest_rank, int  tag  ) const

inline

Sends the data to the dest_rank nonblocking.

Returns

Future<T> containing the send buffer, completes when data is send

max() [1/2]

template<typename T >

T Dune::Communication< MPI_Comm >::max ( const T &  in ) const

inline

Compute the maximum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

Referenced by Dune::PDELab::SolverStatistics< T >::max().

max() [2/2]

template<typename T >

int Dune::Communication< MPI_Comm >::max ( T *  inout, int  len  ) const

inline

Compute the maximum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

min() [1/2]

template<typename T >

T Dune::Communication< MPI_Comm >::min ( const T &  in ) const

inline

Compute the minimum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

Referenced by Dune::PDELab::SolverStatistics< T >::min().

min() [2/2]

template<typename T >

int Dune::Communication< MPI_Comm >::min ( T *  inout, int  len  ) const

inline

Compute the minimum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

prod() [1/2]

template<typename T >

T Dune::Communication< MPI_Comm >::prod ( const T &  in ) const

inline

Compute the product of the argument over all processes and return the result in every process. Assumes that T has an operator*.

prod() [2/2]

template<typename T >

int Dune::Communication< MPI_Comm >::prod ( T *  inout, int  len  ) const

inline

Compute the product of the argument over all processes and return the result in every process. Assumes that T has an operator*.

rank()

int Dune::Communication< MPI_Comm >::rank ( ) const

inline

Return rank, is between 0 and size()-1.

Referenced by Dune::graphRepartition(), and Dune::storeMatrixMarket().

recv()

template<class T >

T Dune::Communication< MPI_Comm >::recv ( T &&  data, int  source_rank, int  tag, MPI_Status *  status = MPI_STATUS_IGNORE  ) const

inline

Receives the data from the source_rank.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

scatter()

template<typename T >

int Dune::Communication< MPI_Comm >::scatter ( const T *  sendData, T *  recvData, int  len, int  root  ) const

inline

Scatter array from a root to all other task.

The root process sends the elements with index from k*len to (k+1)*len-1 in its array to task k, which stores it at index 0 to len-1.

Parameters

[in]	sendData	The array to scatter. Might have length zero on non-root tasks.
[out]	recvData	The buffer to store the received data in. Upon completion of the method each task will have same data stored there as the one in send buffer of the root task before.
[in]	len	The number of elements in the recv buffer.
[in]	root	The root task that gathers the data.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

Note

out must have space for P*len elements

scatterv()

template<typename T >

int Dune::Communication< MPI_Comm >::scatterv ( const T *  sendData, int *  sendDataLen, int *  displ, T *  recvData, int  recvDataLen, int  root  ) const

inline

Scatter arrays of variable length from a root to all other tasks.

The root process sends the elements with index from send+displ[k] to send+displ[k]-1 in its array to task k, which stores it at index 0 to recvDataLen-1.

Parameters

[in]	sendData	The array to scatter. May have length zero on non-root tasks.
[in]	sendDataLen	An array with size equal to the number of processes containing the number of elements to scatter to process i at position i, i.e. the number that is passed as recvDataLen argument to this function in process i.
[in]	displ	An array with size equal to the number of processes. Data scattered to process i will be read starting at send+displ[i] on root the process.
[out]	recvData	The buffer to store the received data in. Upon completion of the method each task will have the same data stored there as the one in send buffer of the root task before.
[in]	recvDataLen	The number of elements in the recvData buffer.
[in]	root	The root task that gathers the data.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

send()

template<class T >

int Dune::Communication< MPI_Comm >::send ( const T &  data, int  dest_rank, int  tag  ) const

inline

Sends the data to the dest_rank.

Returns

MPI_SUCCESS (==0) if successful, an MPI error code otherwise

size()

int Dune::Communication< MPI_Comm >::size ( ) const

inline

Number of processes in set, is greater than 0.

Referenced by Dune::graphRepartition().

sum() [1/2]

template<typename T >

T Dune::Communication< MPI_Comm >::sum ( const T &  in ) const

inline

Compute the sum of the argument over all processes and return the result in every process. Assumes that T has an operator+.

Referenced by Dune::PDELab::SolverStatistics< T >::avg(), Dune::OwnerOverlapCopyCommunication< GlobalIdType, LocalIdType >::dot(), Dune::PDELab::SolverStatistics< T >::size(), and Dune::PDELab::SolverStatistics< T >::stddev().

sum() [2/2]

template<typename T >

int Dune::Communication< MPI_Comm >::sum ( T *  inout, int  len  ) const

inline

Compute the sum of the argument over all processes and return the result in every process. Assumes that T has an operator+.

---

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

• dune/common/parallel/mpicommunication.hh