10c312b8eSJed Brown #if !defined(_PETSCSFTYPES_H) 20c312b8eSJed Brown #define _PETSCSFTYPES_H 30c312b8eSJed Brown 40c312b8eSJed Brown /*S 50c312b8eSJed Brown PetscSF - PETSc object for setting up and managing the communication of certain entries of arrays and Vecs between MPI processes. 60c312b8eSJed Brown 70c312b8eSJed Brown Level: intermediate 80c312b8eSJed Brown 90c312b8eSJed Brown Concepts: star forest 100c312b8eSJed Brown 110c312b8eSJed Brown PetscSF uses the concept of star forests to indicate and determine the communication patterns concisely and efficiently. 12*a8d69d7bSBarry Smith A star https://en.wikipedia.org/wiki/Star_(graph_theory) forest is simply a collection of trees of height 1. The leave nodes represent 130c312b8eSJed Brown "ghost locations" for the root nodes. 140c312b8eSJed Brown 159448b7f1SJunchao Zhang .seealso: PetscSFCreate(), VecScatter, VecScatterCreate() 160c312b8eSJed Brown S*/ 170c312b8eSJed Brown typedef struct _p_PetscSF* PetscSF; 180c312b8eSJed Brown 19799f573fSMatthew G. Knepley /*S 20799f573fSMatthew G. Knepley PetscSFNode - specifier of owner and index 21799f573fSMatthew G. Knepley 22799f573fSMatthew G. Knepley Level: beginner 23799f573fSMatthew G. Knepley 24799f573fSMatthew G. Knepley Concepts: indexing, stride, distribution 25799f573fSMatthew G. Knepley 2638ab3f8aSBarry Smith Sample Usage: 2738ab3f8aSBarry Smith $ PetscSFNode *remote; 2838ab3f8aSBarry Smith $ ierr = PetscMalloc1(nleaves,&remote);CHKERRQ(ierr); 2938ab3f8aSBarry Smith $ for (i=0; i<size; i++) { 3038ab3f8aSBarry Smith $ remote[i].rank = i; 3138ab3f8aSBarry Smith $ remote[i].index = rank; 3238ab3f8aSBarry Smith $ } 3338ab3f8aSBarry Smith 3438ab3f8aSBarry Smith Sample Fortran Usage: 3538ab3f8aSBarry Smith $ type(PetscSFNode) remote(6) 3638ab3f8aSBarry Smith $ remote(1)%rank = modulo(rank+size-1,size) 3738ab3f8aSBarry Smith $ remote(1)%index = 1 * stride 3838ab3f8aSBarry Smith 39799f573fSMatthew G. Knepley .seealso: PetscSFSetGraph() 40799f573fSMatthew G. Knepley S*/ 41799f573fSMatthew G. Knepley typedef struct { 42799f573fSMatthew G. Knepley PetscInt rank; /* Rank of owner */ 43799f573fSMatthew G. Knepley PetscInt index; /* Index of node on rank */ 44799f573fSMatthew G. Knepley } PetscSFNode; 45799f573fSMatthew G. Knepley 460c312b8eSJed Brown #endif 47