public static void main(String[] args) throws MPIException {
args = MPI.Init(args);
Intracomm worldProcComm = MPI.COMM_WORLD;
int worldProcRank = worldProcComm.getRank();
int worldProcsCount = worldProcComm.getSize();
int size = Integer.parseInt(args[0]);
Range[] ranges = RangePartitioner.partition(size, worldProcsCount);
Range myRange = ranges[worldProcRank];
String fname = "/dev/shm/mmap.tmp";
try (FileChannel fc =
FileChannel.open(
Paths.get(fname),
StandardOpenOption.CREATE,
StandardOpenOption.WRITE,
StandardOpenOption.READ)) {
int extent = size * Double.BYTES;
bytes = ByteBufferBytes.wrap(fc.map(FileChannel.MapMode.READ_WRITE, 0L, extent));
byteBuffer = bytes.sliceAsByteBuffer(byteBuffer);
byteSlice =
bytes.slice(myRange.getStartIndex() * Double.BYTES, myRange.getLength() * Double.BYTES);
byteBufferSlice = byteSlice.sliceAsByteBuffer(byteBufferSlice);
Win win = new Win(byteBuffer, extent, Double.BYTES, MPI.INFO_NULL, worldProcComm);
for (int i = 0; i < myRange.getLength(); ++i) {
byteSlice.writeDouble(i * Double.BYTES, worldProcRank);
}
win.fence(0);
if (worldProcRank != 0) {
win.put(
byteBufferSlice,
myRange.getLength(),
MPI.DOUBLE,
0,
myRange.getStartIndex(),
myRange.getLength(),
MPI.DOUBLE);
}
win.fence(0);
worldProcComm.barrier();
if (worldProcRank == 0) {
for (int i = 0; i < size; ++i) {
System.out.println(bytes.readDouble(i * Double.BYTES));
}
}
worldProcComm.barrier();
} catch (IOException e) {
e.printStackTrace();
}
MPI.Finalize();
}
