11. Introduction to mpiJava

14. Class hierarchy MPI Group Comm Datatype Status Request package mpi Intracomm Intercomm Prequest Cartcomm Graphcomm

49. The mpiJava Implementation. Lessons Learned.

67. mpiJava performance 1. Shared memory mode

68. mpiJava performance 2. Distributed memory

69. mpiJava demos 1. CFD: inviscid flow

70. mpiJava demos 2. Q-state Potts model

71. Special Topic: HPJava

78. Array of Arrays in Java 0 1 2 3 X Array of array for 2D 0 1 2 3 0 1 2 3 X Y Array of array in irregular structure

79. Multiarray Z True 2-dimensional Array

85. 2-dimensional Array Block-Distributed Over p p.dim(1) p.dim(0) 0 1 a[0,0] a[0,1] a[0,2] a[1,0] a[1,1] a[1,2] a[2,0] a[2,1] a[2,2] a[3,0] a[3,1] a[3,2] a[0,3] a[0,4] a[0,5] a[1,3] a[1,4] a[1,5] a[2,3] a[2,4] a[2,5] a[3,3] a[3,4] a[3,5] a[4,0] a[4,1] a[4,2] a[5,0] a[5,1] a[5,2] a[6,0] a[6,1] a[6,2] a[7,0] a[7,1] a[7,2] a[4,3] a[4,4] a[4,5] a[5,3] a[5,4] a[5,5] a[6,3] a[6,4] a[6,5] a[7,3] a[7,4] a[7,5] 0 1 a[0,6] a[0,7] a[1,6] a[1,7] a[2,6] a[2,7] a[3,6] a[3,7] a[4,6] a[4,7] a[5,6] a[5,7] a[6,6] a[6,7] a[7,6] a[7,7] 2 int N = 8 ; Procs2 p = new Procs(2, 3) ; on(p) { Range x = new BlockRange(N, p.dim(0)) ; Range y = new BlockRange(N, p.dim(1)) ; int [[-,-]] a = new int [[x, y]] ; }

89. Visualization of Ghost Regions a[0,0] a[0,1] a[0,2] a[1,0] a[1,1] a[1,2] a[2,0] a[2,1] a[2,2] a[0,1] a[0,2] a[0,3] a[1,1] a[1,2] a[1,3] a[2,1] a[2,2] a[2,3] a[3,0] a[3,1] a[3,2] a[4,0] a[4,1] a[4,1] a[5,0] a[5,1] a[5,2] a[3,1] a[3,2] a[3,3] a[4,1] a[4,2] a[4,3] a[5,1] a[5,2] a[5,3] 0 0 1 1 a[3,0] a[3,1] a[3,2] a[3,1] a[3,2] a[3,3] a[2,0] a[2,1] a[2,2] a[2,1] a[2,2] a[2,3]

90. Illustration of the effect the writeHalo() function “ Declared” ghost Region of array segment Physical Segment Of array Ghost area written By writeHalo

93. HPJava communication layers Grey font = not yet implemented! Other application- level APIs MPJ and Java version of Adlib mpjdev Pure Java Native MPI SMPs or Networks of PCs Parallel Hardware (e.g. IBM SP3, Sun HPC)