+/* Copyright (c) 2009-2015. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+/* This example should be instructive to learn about SMPI_SHARED_CALL */
+
+#include <stdio.h>
+#include <mpi.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+// Return the number of occurences of the given value between buf[start] and buf[stop-1].
+int count_all(uint8_t *buf, int start, int stop, uint8_t value) {
+ int occ = 0;
+ for(int i = start ; i < stop ; i++) {
+ if(buf[i] == value) {
+ occ ++;
+ }
+ }
+ return occ;
+}
+
+// Return true iff the values from buf[start] to buf[stop-1] are all equal to value.
+int check_all(uint8_t *buf, int start, int stop, uint8_t value) {
+ int occ = count_all(buf, start, stop, value);
+ return occ == stop-start;
+}
+
+// Return true iff "enough" occurences of the given value are between buf[start] and buf[stop-1].
+int check_enough(uint8_t *buf, int start, int stop, uint8_t value) {
+ int page_size = 0x1000;
+ int size = stop-start;
+ if(size <= 2*page_size) // we are not sure to have a whole page that is shared
+ return 1;
+ int occ = count_all(buf, start, stop, value);
+ return occ >= size - 2*page_size;
+}
+
+int main(int argc, char *argv[])
+{
+ MPI_Init(&argc, &argv);
+ int rank;
+ int size;
+ int mem_size = 0x10000000;
+ int shared_blocks[] = {
+ 0, 0x1234567,
+ 0x3456789, 0x3457890,
+ 0x4444444, 0x5555555,
+ 0x8000000, 0x10000000
+ };
+ int nb_blocks = (sizeof(shared_blocks)/sizeof(int))/2;
+ MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+ MPI_Comm_size(MPI_COMM_WORLD, &size);
+ //Let's Allocate a shared memory buffer
+ uint8_t *buf;
+ buf = SMPI_PARTIAL_SHARED_MALLOC(mem_size, shared_blocks, nb_blocks);
+ memset(buf, 0, mem_size);
+ MPI_Barrier(MPI_COMM_WORLD);
+
+ // Process 0 write in shared blocks
+ if(rank == 0) {
+ for(int i = 0; i < nb_blocks; i++) {
+ int start = shared_blocks[2*i];
+ int stop = shared_blocks[2*i+1];
+ memset(buf+start, 42, stop-start);
+ }
+ }
+ MPI_Barrier(MPI_COMM_WORLD);
+ // All processes check that their shared blocks have been written (at least partially)
+ for(int i = 0; i < nb_blocks; i++) {
+ int start = shared_blocks[2*i];
+ int stop = shared_blocks[2*i+1];
+ int is_shared = check_enough(buf, start, stop, 42);
+ printf("[%d] The result of the shared check for block (0x%x, 0x%x) is: %d\n", rank, start, stop, is_shared);
+ }
+
+
+ // Check the private blocks
+ MPI_Barrier(MPI_COMM_WORLD);
+ for(int i = 0; i < nb_blocks-1; i++) {
+ int start = shared_blocks[2*i+1];
+ int stop = shared_blocks[2*i+2];
+ int is_private = check_all(buf, start, stop, 0);
+ printf("[%d] The result of the private check for block (0x%x, 0x%x) is: %d\n", rank, start, stop, is_private);
+ }
+
+ SMPI_SHARED_FREE(buf);
+
+ MPI_Finalize();
+ return 0;
+}
