Detailed Description

A serial communication class.

This communicator can be used if no MPI is available or one wants to run sequentially even if MPI is available and used.

Public Member Functions
gsSerialComm	duplicate () const
	Duplicates the communicator.

int	rank () const
	return rank of process, i.e. zero More...

gsSerialComm	split (int color, int key) const
	Splits the communicator into two.

Static Public Member Functions
template<typename T >
static int	allgather (T sbuf, int count, T rbuf)
	Gathers data from all tasks and distribute it to all. More...

template<typename T >
static int	allgatherv (T in, int sendlen, T out, int recvlen, int displ)
	Gathers data of variable length from all tasks and distribute it to all. More...

template<typename BinaryFunction , typename Type >
static int	allreduce (Type *inout, int len)
	Compute something over all processes for each component of an array and return the result in every process. More...

template<typename BinaryFunction , typename Type >
static void	allreduce (Type in, Type out, int len)
	Compute something over all processes for each component of an array and return the result in every process. More...

static int	barrier ()
	Wait until all processes have arrived at this point in the program.

template<typename T >
static int	broadcast (T *inout, int len, int root)
	Distribute an array from the process with rank root to all other processes.

static int	compare (gsSerialComm comm)
	Compares two communicators.

template<typename T >
static int	gather (T in, T out, int len, int)
	Gather arrays on root task. More...

template<typename T >
static int	gatherv (T in, int sendlen, T out, int recvlen, int displ, int root)
	Gather arrays of variable size on root task. More...

static int	group (const MPI_Group *group_)
	Returns the group of the communicator.

static gsSerialStatus	iprobe (int source, int *flag, int tag=0)
	Query the status from a source process with a defined tag (non-blocking) More...

template<typename T >
static int	irecv (T *out, int len, int source, MPI_Request request, int tag=0)
	Receives data from a source process with a defined tag (non-blocking) More...

template<typename T >
static int	isend (T *in, int len, int dest, MPI_Request request, int tag=0)
	Sends data to a destination process with a defined tag (non-blocking) More...

template<typename T >
static T	max (T &in)
	Compute the maximum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

template<typename T >
static int	max (T *inout, int len)
	Compute the maximum over all processes for each component of an array and return the result in every process. Assumes that T has an operator<.

template<typename T >
static T	min (T &in)
	Compute the minimum of the argument over all processes and return the result in every process. Assumes that T has an operator<.

template<typename T >
static int	min (T *inout, int len)
	Compute the minimum over all processes for each component of an array and return the result in every process. Assumes that T has an operator<.

static std::string	name ()
	Returns the name of the communicator.

static gsSerialStatus	probe (int source, int tag=0)
	Query the status from a source process with a defined tag (blocking) More...

template<typename T >
static T	prod (T &in)
	Compute the product of the argument over all processes and return the result in every process. Assumes that T has an operator*.

template<typename T >
static int	prod (T *inout, int len)
	Compute the product over all processes for each component of an array and return the result in every process. Assumes that T has an operator*.

template<typename T >
static int	recv (T , int, int, int=0, const void =NULL)
	Receives data from a source process with a defined tag (blocking) More...

template<typename T >
static int	scatter (T send, T recv, int len, int root)
	Scatter array from a root to all other task. More...

template<typename T >
static int	scatterv (T send, int sendlen, int displ, T recv, int recvlen, int root)
	Scatter arrays of variable length from a root to all other tasks. More...

template<typename T >
static int	send (T *, int, int, int=0)
	Sends data to a destination process with a defined tag (blocking) More...

static int	size ()
	return rank of process, i.e. one

template<typename T >
static T	sum (T &in)
	Compute the sum of the argument over all processes and return the result in every process. Assumes that T has an operator+.

template<typename T >
static int	sum (T *inout, int len)
	Compute the sum over all processes for each component of an array and return the result in every process. Assumes that T has an operator+.

Member Function Documentation

static int allgather	(	T *	sbuf,
		int	count,
		T *	rbuf
	)

inlinestatic

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.

static int allgatherv	(	T *	in,
		int	sendlen,
		T *	out,
		int *	recvlen,
		int *	displ
	)

inlinestatic

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

static int allreduce	(	Type *	inout,
		int	len
	)

inlinestatic

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

static void allreduce	(	Type *	in,
		Type *	out,
		int	len
	)

inlinestatic

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

in	The array to compute on.
out	The array to store the results in.
len	The number of components in the array

static int gather	(	T *	in,
		T *	out,
		int	len,
		int
	)

inlinestatic

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.

static int gatherv	(	T *	in,
		int	sendlen,
		T *	out,
		int *	recvlen,
		int *	displ,
		int	root
	)

inlinestatic

Gather arrays of variable size on root task.

Each process sends its in array of length sendlen 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]	sendlen	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]	recvlen	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 sendlen 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.

static gsSerialStatus iprobe	(	int	source,
		int *	flag,
		int	tag = `0`
	)

inlinestatic

Query the status from a source process with a defined tag (non-blocking)

One process queries the status of receiving data from the source process source. The argument tag specifies the message ID.

Parameters

[in]	source	The rank of the process which sended the message
[out]	flag	True if a message with the specified source, tag, and communicator is available (logical)
[in]	tag	Specifies the message ID

static int irecv	(	T *	out,
		int	len,
		int	source,
		MPI_Request	request,
		int	tag = `0`
	)

inlinestatic

Receives data from a source process with a defined tag (non-blocking)

One process receives data of length len from the source process source. The argument tag specifies the message ID.

Parameters

[out]	out	The buffer to store the received data in
[in]	len	The number of elements which will be received
[in]	source	The rank of the process which sended the message
[out]	request	communication request
[in]	tag	Specifies the message ID

static int isend	(	T *	in,
		int	len,
		int	dest,
		MPI_Request	request,
		int	tag = `0`
	)

inlinestatic

Sends data to a destination process with a defined tag (non-blocking)

One process sends data of length len to the destination process dest. The argument tag specifies the message ID.

Parameters

[in]	in	The send buffer with the data to send
[in]	len	The number of elements which will be sent
[in]	dest	The rank of the process which should receive the message
[out]	request	communication request
[in]	tag	Specifies the message ID

static gsSerialStatus probe	(	int	source,
		int	tag = `0`
	)

inlinestatic

Query the status from a source process with a defined tag (blocking)

One process queries the status of receiving data from the source process source. The argument tag specifies the message ID.

Parameters

[in]	source	The rank of the process which sended the message
[in]	tag	Specifies the message ID

int rank ( ) const

inline

return rank of process, i.e. zero

This function is intentionally left non-static to avoid compiler warnings of unused object.

static int recv	(	T *	,
		int	,
		int	,
		int	= `0`,
		const void *	= `NULL`
	)

inlinestatic

Receives data from a source process with a defined tag (blocking)

One process receives data of length len from the source process source. The argument tag specifies the message ID.

Parameters

[out]	out	The buffer to store the received data in
[in]	len	The number of elements which will be received
[in]	source	The rank of the process which sended the message
[in]	tag	Specifies the message ID

static int scatter	(	T *	send,
		T *	recv,
		int	len,
		int	root
	)

inlinestatic

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]	send	The array to scatter. Might have length zero on non-root tasks.
[out]	recv	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.

static int scatterv	(	T *	send,
		int *	sendlen,
		int *	displ,
		T *	recv,
		int	recvlen,
		int	root
	)

inlinestatic

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 recvlen-1.

Parameters

[in]	send	The array to scatter. May have length zero on non-root tasks.
[in]	sendlen	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 recvlen 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]	recv	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]	recvlen	The number of elements in the recv buffer.
[in]	root	The root task that gathers the data.

static int send	(	T *	,
		int	,
		int	,
		int	= `0`
	)

inlinestatic

Sends data to a destination process with a defined tag (blocking)

One process sends data of length len to the destination process dest. The argument tag specifies the message ID.

Parameters

[in]	in	The send buffer with the data to send
[in]	len	The number of elements which will be sent
[in]	dest	The rank of the process which should receive the message
[in]	tag	Specifies the message ID

Detailed Description

Public Member Functions

Static Public Member Functions

Member Function Documentation