1c4762a1bSJed Brown! Description: A star forest is a simple tree with one root and zero or more leaves. 2c4762a1bSJed Brown! Many common communication patterns can be expressed as updates of rootdata using leafdata and vice-versa. 3c4762a1bSJed Brown! This example creates a star forest, communicates values using the graph views the graph, then destroys it. 4c4762a1bSJed Brown! 5c4762a1bSJed Brown! This is a copy of ex1.c but currently only tests the broadcast operation 6c4762a1bSJed Brown 7c4762a1bSJed Brown program main 8c4762a1bSJed Brown#include <petsc/finclude/petscvec.h> 98c8af28eSPedro Ricardo C. Souza use petscmpi ! or mpi or mpi_f08 10c4762a1bSJed Brown use petscvec 11c4762a1bSJed Brown implicit none 12c4762a1bSJed Brown 13c4762a1bSJed Brown PetscErrorCode ierr 14c4762a1bSJed Brown PetscInt i,nroots,nrootsalloc,nleaves,nleavesalloc,mine(6),stride 15c4762a1bSJed Brown type(PetscSFNode) remote(6) 16c4762a1bSJed Brown PetscMPIInt rank,size 17c4762a1bSJed Brown PetscSF sf 18c4762a1bSJed Brown PetscInt rootdata(6),leafdata(6) 19c4762a1bSJed Brown 20c4762a1bSJed Brown! used with PetscSFGetGraph() 21c4762a1bSJed Brown type(PetscSFNode), pointer :: gremote(:) 22c4762a1bSJed Brown PetscInt, pointer :: gmine(:) 23c4762a1bSJed Brown PetscInt gnroots,gnleaves; 24c4762a1bSJed Brown 25*6497c311SBarry Smith PetscMPIInt niranks,nranks 2694a885e8SJunchao Zhang PetscMPIInt, pointer :: iranks(:), ranks(:) 2794a885e8SJunchao Zhang PetscInt, pointer :: ioffset(:),irootloc(:),roffset(:),rmine(:),rremote(:) 2894a885e8SJunchao Zhang 29d8606c27SBarry Smith PetscCallA(PetscInitialize(ierr)) 30c4762a1bSJed Brown stride = 2 31d8606c27SBarry Smith PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr)) 32d8606c27SBarry Smith PetscCallMPIA(MPI_Comm_size(PETSC_COMM_WORLD,size,ierr)) 33c4762a1bSJed Brown 34c4762a1bSJed Brown if (rank == 0) then 35c4762a1bSJed Brown nroots = 3 36c4762a1bSJed Brown else 37c4762a1bSJed Brown nroots = 2 38c4762a1bSJed Brown endif 39c4762a1bSJed Brown nrootsalloc = nroots * stride; 40c4762a1bSJed Brown if (rank > 0) then 41c4762a1bSJed Brown nleaves = 3 42c4762a1bSJed Brown else 43c4762a1bSJed Brown nleaves = 2 44c4762a1bSJed Brown endif 45c4762a1bSJed Brown nleavesalloc = nleaves * stride 46c4762a1bSJed Brown if (stride > 1) then 47c4762a1bSJed Brown do i=1,nleaves 48c4762a1bSJed Brown mine(i) = stride * (i-1) 49c4762a1bSJed Brown enddo 50c4762a1bSJed Brown endif 51c4762a1bSJed Brown 52c4762a1bSJed Brown! Left periodic neighbor 53c4762a1bSJed Brown remote(1)%rank = modulo(rank+size-1,size) 54c4762a1bSJed Brown remote(1)%index = 1 * stride 55c4762a1bSJed Brown! Right periodic neighbor 56c4762a1bSJed Brown remote(2)%rank = modulo(rank+1,size) 57c4762a1bSJed Brown remote(2)%index = 0 * stride 58c4762a1bSJed Brown if (rank > 0) then ! All processes reference rank 0, index 59c4762a1bSJed Brown remote(3)%rank = 0 60c4762a1bSJed Brown remote(3)%index = 2 * stride 61c4762a1bSJed Brown endif 62c4762a1bSJed Brown 63c4762a1bSJed Brown! Create a star forest for communication 64d8606c27SBarry Smith PetscCallA(PetscSFCreate(PETSC_COMM_WORLD,sf,ierr)) 65d8606c27SBarry Smith PetscCallA(PetscSFSetFromOptions(sf,ierr)) 66d8606c27SBarry Smith PetscCallA(PetscSFSetGraph(sf,nrootsalloc,nleaves,mine,PETSC_COPY_VALUES,remote,PETSC_COPY_VALUES,ierr)) 67d8606c27SBarry Smith PetscCallA(PetscSFSetUp(sf,ierr)) 68c4762a1bSJed Brown 69c4762a1bSJed Brown! View graph, mostly useful for debugging purposes. 70d8606c27SBarry Smith PetscCallA(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL,ierr)) 71d8606c27SBarry Smith PetscCallA(PetscSFView(sf,PETSC_VIEWER_STDOUT_WORLD,ierr)) 72d8606c27SBarry Smith PetscCallA(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD,ierr)) 73c4762a1bSJed Brown 742d4ee042Sprj-! Allocate space for send and receive buffers. This example communicates PetscInt, but other types, including 75c4762a1bSJed Brown! * user-defined structures, could also be used. 76c4762a1bSJed Brown! Set rootdata buffer to be broadcast 77c4762a1bSJed Brown do i=1,nrootsalloc 78c4762a1bSJed Brown rootdata(i) = -1 79c4762a1bSJed Brown enddo 80c4762a1bSJed Brown do i=1,nroots 81c4762a1bSJed Brown rootdata(1 + (i-1)*stride) = 100*(rank+1) + i - 1 82c4762a1bSJed Brown enddo 83c4762a1bSJed Brown 84c4762a1bSJed Brown! Initialize local buffer, these values are never used. 85c4762a1bSJed Brown do i=1,nleavesalloc 86c4762a1bSJed Brown leafdata(i) = -1 87c4762a1bSJed Brown enddo 88c4762a1bSJed Brown 89c4762a1bSJed Brown! Broadcast entries from rootdata to leafdata. Computation or other communication can be performed between the begin and end calls. 90d8606c27SBarry Smith PetscCallA(PetscSFBcastBegin(sf,MPIU_INTEGER,rootdata,leafdata,MPI_REPLACE,ierr)) 91d8606c27SBarry Smith PetscCallA(PetscSFBcastEnd(sf,MPIU_INTEGER,rootdata,leafdata,MPI_REPLACE,ierr)) 92dcb3e689SBarry Smith PetscCallA(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD,'## Bcast Rootdata\n',ierr)) 93d8606c27SBarry Smith PetscCallA(PetscIntView(nrootsalloc,rootdata,PETSC_VIEWER_STDOUT_WORLD,ierr)) 94dcb3e689SBarry Smith PetscCallA(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD,'## Bcast Leafdata\n',ierr)) 95d8606c27SBarry Smith PetscCallA(PetscIntView(nleavesalloc,leafdata,PETSC_VIEWER_STDOUT_WORLD,ierr)) 96c4762a1bSJed Brown 979037d788SNicholas Arnold-Medabalimi! Reduce entries from leafdata to rootdata. Computation or other communication can be performed between the begin and end calls. 989037d788SNicholas Arnold-Medabalimi PetscCallA(PetscSFReduceBegin(sf,MPIU_INTEGER,leafdata,rootdata,MPI_SUM,ierr)) 999037d788SNicholas Arnold-Medabalimi PetscCallA(PetscSFReduceEnd(sf,MPIU_INTEGER,leafdata,rootdata,MPI_SUM,ierr)) 100dcb3e689SBarry Smith PetscCallA(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD,'## Reduce Leafdata\n',ierr)) 1019037d788SNicholas Arnold-Medabalimi PetscCallA(PetscIntView(nleavesalloc,leafdata,PETSC_VIEWER_STDOUT_WORLD,ierr)) 102dcb3e689SBarry Smith PetscCallA(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD,'## Reduce Rootdata\n',ierr)) 1039037d788SNicholas Arnold-Medabalimi PetscCallA(PetscIntView(nrootsalloc,rootdata,PETSC_VIEWER_STDOUT_WORLD,ierr)) 1049037d788SNicholas Arnold-Medabalimi 105d8606c27SBarry Smith PetscCallA(PetscSFGetGraph(sf,gnroots,gnleaves,gmine,gremote,ierr)) 106dcb3e689SBarry Smith PetscCheckA(gnleaves .eq. nleaves,PETSC_COMM_WORLD,PETSC_ERR_PLIB,'nleaves returned from PetscSFGetGraph() does not match that set with PetscSFSetGraph()') 107c4762a1bSJed Brown do i=1,nleaves 108dcb3e689SBarry Smith PetscCheckA(gmine(i) .eq. mine(i),PETSC_COMM_WORLD,PETSC_ERR_PLIB,'Root from PetscSFGetGraph() does not match that set with PetscSFSetGraph()') 109c4762a1bSJed Brown enddo 110c4762a1bSJed Brown do i=1,nleaves 111dcb3e689SBarry Smith PetscCheckA(gremote(i)%index .eq. remote(i)%index,PETSC_COMM_WORLD,PETSC_ERR_PLIB,'Leaf from PetscSFGetGraph() does not match that set with PetscSFSetGraph()') 112c4762a1bSJed Brown enddo 113c4762a1bSJed Brown 114c4762a1bSJed Brown deallocate(gremote) 11594a885e8SJunchao Zhang 11694a885e8SJunchao Zhang! Test PetscSFGet{Leaf,Root}Ranks 11794a885e8SJunchao Zhang PetscCallA(PetscSFGetLeafRanks(sf,niranks,iranks,ioffset,irootloc,ierr)) 11894a885e8SJunchao Zhang PetscCallA(PetscSFGetRootRanks(sf,nranks,ranks,roffset,rmine,rremote,ierr)) 11994a885e8SJunchao Zhang 120c4762a1bSJed Brown! Clean storage for star forest. 121d8606c27SBarry Smith PetscCallA(PetscSFDestroy(sf,ierr)) 1228dbb0df6SBarry Smith 123da81f932SPierre Jolivet! Create a star forest with continuous leaves and hence no buffer 124d8606c27SBarry Smith PetscCallA(PetscSFCreate(PETSC_COMM_WORLD,sf,ierr)) 125d8606c27SBarry Smith PetscCallA(PetscSFSetFromOptions(sf,ierr)) 1265d83a8b1SBarry Smith PetscCallA(PetscSFSetGraph(sf,nrootsalloc,nleaves,PETSC_NULL_INTEGER_ARRAY,PETSC_COPY_VALUES,remote,PETSC_COPY_VALUES,ierr)) 127d8606c27SBarry Smith PetscCallA(PetscSFSetUp(sf,ierr)) 1288dbb0df6SBarry Smith 1298dbb0df6SBarry Smith! View graph, mostly useful for debugging purposes. 130d8606c27SBarry Smith PetscCallA(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL,ierr)) 131d8606c27SBarry Smith PetscCallA(PetscSFView(sf,PETSC_VIEWER_STDOUT_WORLD,ierr)) 132d8606c27SBarry Smith PetscCallA(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD,ierr)) 1338dbb0df6SBarry Smith 134d8606c27SBarry Smith PetscCallA(PetscSFGetGraph(sf,gnroots,gnleaves,gmine,gremote,ierr)) 135dcb3e689SBarry Smith PetscCheckA(loc(gmine) .eq. loc(PETSC_NULL_INTEGER),PETSC_COMM_WORLD,PETSC_ERR_PLIB,'Leaves from PetscSFGetGraph() not null as expected') 1368dbb0df6SBarry Smith deallocate(gremote) 137d8606c27SBarry Smith PetscCallA(PetscSFDestroy(sf,ierr)) 138d8606c27SBarry Smith PetscCallA(PetscFinalize(ierr)) 139c4762a1bSJed Brown end 140c4762a1bSJed Brown 141c4762a1bSJed Brown!/*TEST 142c4762a1bSJed Brown! build: 143dfd57a17SPierre Jolivet! requires: defined(PETSC_HAVE_FORTRAN_TYPE_STAR) 144c4762a1bSJed Brown! 145c4762a1bSJed Brown! test: 146c4762a1bSJed Brown! nsize: 3 147c4762a1bSJed Brown! 148c4762a1bSJed Brown!TEST*/ 149