Fix the communication optimization.

[simgrid.git] / src / smpi / smpi_shared.cpp

diff --git a/src/smpi/smpi_shared.cpp b/src/smpi/smpi_shared.cpp
index 1737ea7..e629da9 100644 (file)
--- a/src/smpi/smpi_shared.cpp
+++ b/src/smpi/smpi_shared.cpp
@@ -295,11 +295,12 @@ void *smpi_shared_malloc_global__(size_t size, const char *file, int line, int *
   if(shared_block_offsets[0] > 0) {
     newmeta.private_blocks.push_back(std::make_pair(0, shared_block_offsets[0]));
   }
-  for(int i_block = 0; i_block < nb_shared_blocks-1; i_block ++) {
+  int i_block;
+  for(i_block = 0; i_block < nb_shared_blocks-1; i_block ++) {
     newmeta.private_blocks.push_back(std::make_pair(shared_block_offsets[2*i_block+1], shared_block_offsets[2*i_block+2]));
   }
-  if(shared_block_offsets[nb_shared_blocks-1] < size) {
-    newmeta.private_blocks.push_back(std::make_pair(shared_block_offsets[nb_shared_blocks-1], size));
+  if(shared_block_offsets[2*i_block+1] < size) {
+    newmeta.private_blocks.push_back(std::make_pair(shared_block_offsets[2*i_block+1], size));
   }
   allocs_metadata[mem] = newmeta;
 
@@ -352,7 +353,8 @@ int smpi_is_shared(void* ptr, std::vector<std::pair<int, int>> &private_blocks,
       return 0;
     low --;
     if (ptr < (char*)low->first + low->second.size) {
-      *offset = ((uint8_t*) low->first) - ((uint8_t*)ptr);
+      xbt_assert(ptr > (char*)low->first, "Oops, there seems to be a bug in the shared memory metadata.");
+      *offset = ((uint8_t*)ptr) - ((uint8_t*) low->first);
       private_blocks = low->second.private_blocks;
       return 1;
     }