X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b3a2217b5c973d5a79c43d555162d2d516aa2631..39aa88227f8cff926c10773ec34cf8decb85a05b:/src/mc/mc_object_info.cpp

diff --git a/src/mc/mc_object_info.cpp b/src/mc/mc_object_info.cpp
index 6034269268..3d3703c3c6 100644
--- a/src/mc/mc_object_info.cpp
+++ b/src/mc/mc_object_info.cpp
@@ -35,6 +35,7 @@ Type::Type()
   this->byte_size = 0;
   this->element_count = 0;
   this->is_pointer_type = 0;
+  this->type_id = 0;
   this->subtype = nullptr;
   this->full_type = nullptr;
 }
@@ -46,6 +47,7 @@ Variable::Variable()
   this->dwarf_offset = 0;
   this->global = 0;
   this->type = nullptr;
+  this->type_id = 0;
   this->address = nullptr;
   this->start_scope = 0;
   this->object_info = nullptr;
@@ -68,7 +70,6 @@ Frame::Frame()
 ObjectInformation::ObjectInformation()
 {
   this->flags = 0;
-  this->file_name = nullptr;
   this->start = nullptr;
   this->end = nullptr;
   this->start_exec = nullptr;
@@ -77,34 +78,21 @@ ObjectInformation::ObjectInformation()
   this->end_rw = nullptr;
   this->start_ro = nullptr;
   this->end_ro = nullptr;
-  this->subprograms = xbt_dict_new_homogeneous(mc_frame_free);
-  this->types = xbt_dict_new_homogeneous((void (*)(void *)) mc_type_free);
-  this->full_types_by_name = xbt_dict_new_homogeneous(NULL);
-  this->functions_index = nullptr;
-}
-
-ObjectInformation::~ObjectInformation()
-{
-  xbt_free(this->file_name);
-  xbt_dict_free(&this->subprograms);
-  xbt_dict_free(&this->types);
-  xbt_dict_free(&this->full_types_by_name);
-  xbt_dynar_free(&this->functions_index);
 }
 
 /** Find the DWARF offset for this ELF object
  *
  *  An offset is applied to address found in DWARF:
  *
- *  <ul>
- *    <li>for an executable obejct, addresses are virtual address
- *        (there is no offset) i.e. \f$\text{virtual address} = \{dwarf address}\f$;</li>
- *    <li>for a shared object, the addreses are offset from the begining
- *        of the shared object (the base address of the mapped shared
- *        object must be used as offset
- *        i.e. \f$\text{virtual address} = \text{shared object base address}
- *             + \text{dwarf address}\f$.</li>
+ *  * for an executable obejct, addresses are virtual address
+ *    (there is no offset) i.e.
+ *    \f$\text{virtual address} = \{dwarf address}\f$;
  *
+ *  * for a shared object, the addreses are offset from the begining
+ *    of the shared object (the base address of the mapped shared
+ *    object must be used as offset
+ *    i.e. \f$\text{virtual address} = \text{shared object base address}
+ *             + \text{dwarf address}\f$.
  */
 void *ObjectInformation::base_address() const
 {
@@ -119,22 +107,43 @@ void *ObjectInformation::base_address() const
   return result;
 }
 
-mc_frame_t ObjectInformation::find_function(const void *ip) const
+/* Find a function by instruction pointer */
+simgrid::mc::Frame* ObjectInformation::find_function(const void *ip) const
 {
-  xbt_dynar_t dynar = this->functions_index;
-  mc_function_index_item_t base =
-      (mc_function_index_item_t) xbt_dynar_get_ptr(dynar, 0);
+  /* This is implemented by binary search on a sorted array.
+   *
+   * We do quite a lot ot those so we want this to be cache efficient.
+   * We pack the only information we need in the index entries in order
+   * to successfully do the binary search. We do not need the high_pc
+   * during the binary search (only at the end) so it is not included
+   * in the index entry. We could use parallel arrays as well.
+   *
+   * We cannot really use the std:: alogrithm for this.
+   * We could use std::binary_search by including the high_pc inside
+   * the FunctionIndexEntry.
+   */
+  const simgrid::mc::FunctionIndexEntry* base =
+    this->functions_index.data();
   int i = 0;
-  int j = xbt_dynar_length(dynar) - 1;
+  int j = this->functions_index.size() - 1;
   while (j >= i) {
     int k = i + ((j - i) / 2);
-    if (ip < base[k].low_pc) {
+
+    /* In most of the search, we do not dereference the base[k].function.
+     * This way the memory accesses are located in the base[k] array. */
+    if (ip < base[k].low_pc)
       j = k - 1;
-    } else if (ip >= base[k].high_pc) {
+    else if (k < j && ip >= base[k + 1].low_pc)
       i = k + 1;
-    } else {
+
+    /* At this point, the search is over.
+     * Either we have found the correct function or we do not know
+     * any function corresponding to this instruction address.
+     * Only at the point do we derefernce the function pointer. */
+    else if (ip < base[k].function->high_pc)
       return base[k].function;
-    }
+    else
+      return nullptr;
   }
   return nullptr;
 }