From 7fab262f647f4ebc429a12fdd4d0a02dbaa032c7 Mon Sep 17 00:00:00 2001
From: Convex Function <329364@wright.mathepool.rwth-aachen.de>
Date: Wed, 2 Apr 2014 09:08:48 +0200
Subject: [PATCH] Added methods scatterv, gatherv and allgatherv to
collectivecommunication
---
.../parallel/collectivecommunication.hh | 74 +++++++++++++++++++
.../parallel/mpicollectivecommunication.hh | 28 +++++++
2 files changed, 102 insertions(+)
diff --git a/dune/common/parallel/collectivecommunication.hh b/dune/common/parallel/collectivecommunication.hh
index d3c469a4f..f4e91d163 100644
--- a/dune/common/parallel/collectivecommunication.hh
+++ b/dune/common/parallel/collectivecommunication.hh
@@ -198,6 +198,32 @@ namespace Dune
return 0;
}
+ /** @brief 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.
+ * @param[in] in The send buffer with the data to be sent
+ * @param[in] sendlen The number of elements to send on each task
+ * @param[out] out The buffer to store the received data in. May have length zero on non-root
+ * tasks.
+ * @param[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.
+ * @param[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] on the root process.
+ * May have length zero on non-root tasks.
+ * @param[out] root The root task that gathers the data.
+ */
+ template<typename T>
+ int gatherv (T* in, int sendlen, T* out, int* recvlen, int* displ, int root) const
+ {
+ for (int i=*displ; i<sendlen; i++)
+ out[i] = in[i];
+ return 0;
+ }
+
/** @brief 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
@@ -218,6 +244,31 @@ namespace Dune
return 0;
}
+ /** @brief 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.
+ * @param[in] send The array to scatter. May have length zero on non-root
+ * tasks.
+ * @param[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.
+ * @param[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.
+ * @param[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.
+ * @param[in] recvlen The number of elements in the recv buffer.
+ * @param[out] root The root task that gathers the data.
+ */
+ template<typename T>
+ int scatterv (T* send, int* sendlen, int* displ, T* recv, int recvlen, int root) const
+ {
+ for (int i=*displ; i<*sendlen; i++)
+ recv[i] = send[i];
+ return 0;
+ }
+
/**
* @brief Gathers data from all tasks and distribute it to all.
*
@@ -238,6 +289,29 @@ namespace Dune
return 0;
}
+ /**
+ * @brief 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.
+ *
+ * @param[in] in The send buffer with the data to send.
+ * @param[in] sendlen The number of elements to send on each task.
+ * @param[out] out The buffer to store the received data in.
+ * @param[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.
+ * @param[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].
+ */
+ template<typename T>
+ int allgatherv (T* in, int sendlen, T* out, int* recvlen, int* displ) const
+ {
+ for (int i=*displ; i<sendlen; i++)
+ out[i] = in[i];
+ return 0;
+ }
+
/**
* @brief Compute something over all processes
* for each component of an array and return the result
diff --git a/dune/common/parallel/mpicollectivecommunication.hh b/dune/common/parallel/mpicollectivecommunication.hh
index 7433e19bb..8b57b538d 100644
--- a/dune/common/parallel/mpicollectivecommunication.hh
+++ b/dune/common/parallel/mpicollectivecommunication.hh
@@ -258,6 +258,15 @@ namespace Dune
root,communicator);
}
+ //! @copydoc CollectiveCommunication::gatherv()
+ template<typename T>
+ int gatherv (T* in, int sendlen, T* out, int* recvlen, int* displ, int root) const
+ {
+ return MPI_Gatherv(in,sendlen,MPITraits<T>::getType(),
+ out,recvlen,displ,MPITraits<T>::getType(),
+ root,communicator);
+ }
+
//! @copydoc CollectiveCommunication::scatter()
//! @note out must have space for P*len elements
template<typename T>
@@ -268,6 +277,16 @@ namespace Dune
root,communicator);
}
+ //! @copydoc CollectiveCommunication::scatterv()
+ template<typename T>
+ int scatterv (T* send, int* sendlen, int* displ, T* recv, int recvlen, int root) const
+ {
+ return MPI_Scatterv(send,sendlen,displ,MPITraits<T>::getType(),
+ recv,recvlen,MPITraits<T>::getType(),
+ root,communicator);
+ }
+
+
operator MPI_Comm () const
{
return communicator;
@@ -282,6 +301,15 @@ namespace Dune
communicator);
}
+ //! @copydoc CollectiveCommunication::allgatherv()
+ template<typename T>
+ int allgatherv (T* in, int sendlen, T* out, int* recvlen, int* displ) const
+ {
+ return MPI_Allgatherv(in,sendlen,MPITraits<T>::getType(),
+ out,recvlen,displ,MPITraits<T>::getType(),
+ communicator);
+ }
+
//! @copydoc CollectiveCommunication::allreduce(Type* inout,int len) const
template<typename BinaryFunction, typename Type>
int allreduce(Type* inout, int len) const
--
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