X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4bd100c60f5ce9eb90336facb97e09e1db932ca4..99a794dae9b8a2ddbe8cd650cad97105f41f94bf:/src/mc/mc_compare.c

diff --git a/src/mc/mc_compare.c b/src/mc/mc_compare.c
index 873205dc7d..f9b125b64b 100644
--- a/src/mc/mc_compare.c
+++ b/src/mc/mc_compare.c
@@ -1,8 +1,11 @@
-/* Copyright (c) 2008-2012 Da SimGrid Team. All rights reserved.            */
+/* Copyright (c) 2012-2014. 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. */
 
+#include <inttypes.h>
+
 #include "mc_private.h"
 
 #include "xbt/mmalloc.h"
@@ -10,282 +13,408 @@
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, mc,
                                 "Logging specific to mc_compare");
 
-static int heap_region_compare(void *d1, void *d2, size_t size);
+typedef struct s_pointers_pair{
+  void *p1;
+  void *p2;
+}s_pointers_pair_t, *pointers_pair_t;
+
+__thread xbt_dynar_t compared_pointers;
 
-static int compare_stack(stack_region_t s1, stack_region_t s2, void *sp1, void *sp2, void *heap1, void *heap2, xbt_dynar_t equals);
-static int is_heap_equality(xbt_dynar_t equals, void *a1, void *a2);
-static size_t heap_ignore_size(void *address);
+/************************** Free functions ****************************/
+/********************************************************************/
 
-static void stack_region_free(stack_region_t s);
-static void heap_equality_free(heap_equality_t e);
+static void stack_region_free(stack_region_t s){
+  if(s){
+    xbt_free(s->process_name);
+    xbt_free(s);
+  }
+}
 
-static int is_stack_ignore_variable(char *frame, char *var_name);
-static int compare_local_variables(char *s1, char *s2, xbt_dynar_t heap_equals);
+static void stack_region_free_voidp(void *s){
+  stack_region_free((stack_region_t) * (void **) s);
+}
+
+static void pointers_pair_free(pointers_pair_t p){
+  xbt_free(p);
+}
+
+static void pointers_pair_free_voidp(void *p){
+  pointers_pair_free((pointers_pair_t) * (void **)p);
+}
+
+/************************** Snapshot comparison *******************************/
+/******************************************************************************/
+
+/** \brief Try to add a pair a compared pointers to the set of compared pointers
+ *
+ *  \result !=0 if the pointers were added (they were not in the set),
+ *      0 otherwise (they were already in the set)
+ */
+static int add_compared_pointers(void *p1, void *p2){
+
+  pointers_pair_t new_pair = xbt_new0(s_pointers_pair_t, 1);
+  new_pair->p1 = p1;
+  new_pair->p2 = p2;
+  
+  if(xbt_dynar_is_empty(compared_pointers)){
+    xbt_dynar_push(compared_pointers, &new_pair);
+    return 1;
+  }
 
-static size_t heap_ignore_size(void *address){
   unsigned int cursor = 0;
   int start = 0;
-  int end = xbt_dynar_length(mc_heap_comparison_ignore) - 1;
-  mc_heap_ignore_region_t region;
+  int end = xbt_dynar_length(compared_pointers) - 1;
+  pointers_pair_t pair = NULL;
+
+  pointers_pair_t* p = (pointers_pair_t*) xbt_dynar_get_ptr(compared_pointers, 0);
 
   while(start <= end){
     cursor = (start + end) / 2;
-    region = (mc_heap_ignore_region_t)xbt_dynar_get_as(mc_heap_comparison_ignore, cursor, mc_heap_ignore_region_t);
-    if(region->address == address)
-      return region->size;
-    if(region->address < address)
+    pair = p[cursor];
+    if(pair->p1 < p1){
+      start = cursor + 1;
+    } else if(pair->p1 > p1) {
+      end = cursor - 1 ;
+    } else if(pair->p2 < p2){
       start = cursor + 1;
-    if(region->address > address)
-      end = cursor - 1;   
+    } else if(pair->p2 > p2) {
+      end = cursor - 1 ;
+    } else {
+      pointers_pair_free(new_pair);
+      return 0;
+    }
   }
 
-  return 0;
+  if(pair->p1 < p1)
+    xbt_dynar_insert_at(compared_pointers, cursor + 1, &new_pair);
+  else if(pair->p1 > p1)
+    xbt_dynar_insert_at(compared_pointers, cursor, &new_pair);
+  else if(pair->p2 < p2)
+    xbt_dynar_insert_at(compared_pointers, cursor + 1, &new_pair);
+  else if(pair->p2 > p2)
+    xbt_dynar_insert_at(compared_pointers, cursor, &new_pair);
+  else
+    xbt_die("Unrecheable");
+
+  return 1;
 }
 
-static int compare_global_variables(int region_type, void *d1, void *d2, xbt_dynar_t equals){
+static int compare_areas_with_type(void *area1, void *area2, mc_snapshot_t snapshot1, mc_snapshot_t snapshot2, dw_type_t type, int region_size, int region_type, void *start_data, int pointer_level){
 
   unsigned int cursor = 0;
-  size_t offset; 
-  int i = 0;
-  global_variable_t current_var; 
-  int pointer_align; 
-  void *addr_pointed1 = NULL, *addr_pointed2 = NULL;
-  int res_compare = 0;
-
-  if(region_type == 1){ /* libsimgrid */
-    xbt_dynar_foreach(mc_global_variables, cursor, current_var){
-      if(current_var->address < start_data_libsimgrid)
-        continue;
-      offset = (char *)current_var->address - (char *)start_data_libsimgrid;
-      i = 0;
-      while(i < current_var->size){
-        if(memcmp((char*)d1 + offset + i, (char*)d2 + offset + i, 1) != 0){
-          pointer_align = (i / sizeof(void*)) * sizeof(void*); 
-          addr_pointed1 = *((void **)((char *)d1 + offset + pointer_align));
-          addr_pointed2 = *((void **)((char *)d2 + offset + pointer_align));
-          if((addr_pointed1 > start_plt_libsimgrid && addr_pointed1 < end_plt_libsimgrid) || (addr_pointed2 > start_plt_libsimgrid && addr_pointed2 < end_plt_libsimgrid)){
-            i = current_var->size;
-            continue;
-          }else{
-            if((addr_pointed1 > std_heap) && ((char *)addr_pointed1 < (char *)std_heap + STD_HEAP_SIZE) && (addr_pointed2 > std_heap) && ((char *)addr_pointed2 < (char *)std_heap + STD_HEAP_SIZE)){
-              res_compare = compare_area(addr_pointed1, addr_pointed2, NULL, equals);
-              if(res_compare == 1){
-                #ifdef MC_VERBOSE
-                  XBT_VERB("Different global variable in libsimgrid : %s at addresses %p - %p (size = %zu)", current_var->name, (char *)d1+offset, (char *)d2+offset, current_var->size);
-                #endif
-                return 1;
-              }
-            }else{
-              #ifdef MC_VERBOSE
-                XBT_VERB("Different global variable in libsimgrid : %s at addresses %p - %p (size = %zu)", current_var->name, (char *)d1+offset, (char *)d2+offset, current_var->size);
-              #endif
-              return 1;
-            }
-           
-          }
-        } 
-        i++;
-      }
+  dw_type_t member, subtype, subsubtype;
+  int elm_size, i, res;
+  void *addr_pointed1, *addr_pointed2;
+
+  switch(type->type){
+  case DW_TAG_unspecified_type:
+    return 1;
+
+  case DW_TAG_base_type:
+  case DW_TAG_enumeration_type:
+  case DW_TAG_union_type:
+    return (memcmp(area1, area2, type->byte_size) != 0);
+    break;
+  case DW_TAG_typedef:
+  case DW_TAG_volatile_type:
+  case DW_TAG_const_type:
+    return compare_areas_with_type(area1, area2, snapshot1, snapshot2, type->subtype, region_size, region_type, start_data, pointer_level);
+    break;
+  case DW_TAG_array_type:
+    subtype = type->subtype;
+    switch(subtype->type){
+    case DW_TAG_unspecified_type:
+      return 1;
+
+    case DW_TAG_base_type:
+    case DW_TAG_enumeration_type:
+    case DW_TAG_pointer_type:
+    case DW_TAG_reference_type:
+    case DW_TAG_rvalue_reference_type:
+    case DW_TAG_structure_type:
+    case DW_TAG_class_type:
+    case DW_TAG_union_type:
+      if(subtype->full_type)
+        subtype = subtype->full_type;
+      elm_size = subtype->byte_size;
+      break;
+    case DW_TAG_const_type:
+    case DW_TAG_typedef:
+    case DW_TAG_volatile_type:
+      subsubtype = subtype->subtype;
+      if(subsubtype->full_type)
+          subsubtype = subsubtype->full_type;
+      elm_size = subsubtype->byte_size;
+      break;
+    default : 
+      return 0;
+      break;
     }
-  }else{ /* binary */
-    xbt_dynar_foreach(mc_global_variables, cursor, current_var){
-      if(current_var->address > start_data_libsimgrid)
-        break;
-      offset = (char *)current_var->address - (char *)start_data_binary;
-      i = 0;
-      while(i < current_var->size){
-        if(memcmp((char*)d1 + offset + i, (char*)d2 + offset + i, 1) != 0){
-          pointer_align = (i / sizeof(void*)) * sizeof(void*); 
-          addr_pointed1 = *((void **)((char *)d1 + offset + pointer_align));
-          addr_pointed2 = *((void **)((char *)d2 + offset + pointer_align));
-          if((addr_pointed1 > start_plt_binary && addr_pointed1 < end_plt_binary) || (addr_pointed2 > start_plt_binary && addr_pointed2 < end_plt_binary)){
-            i = current_var->size;
-            continue;
-          }else{
-            if((addr_pointed1 > std_heap) && ((char *)addr_pointed1 < (char *)std_heap + STD_HEAP_SIZE) && (addr_pointed2 > std_heap) && ((char *)addr_pointed2 < (char *)std_heap + STD_HEAP_SIZE)){
-              res_compare = compare_area(addr_pointed1, addr_pointed2, NULL, equals);
-              if(res_compare == 1){
-                #ifdef MC_VERBOSE
-                  XBT_VERB("Different global variable in binary : %s at addresses %p - %p (size = %zu)", current_var->name, (char *)d1+offset, (char *)d2+offset, current_var->size);
-                #endif
-                return 1;
-              }
-            }else{
-              #ifdef MC_VERBOSE
-                XBT_VERB("Different global variable in binary : %s at addresses %p - %p (size = %zu)", current_var->name, (char *)d1+offset, (char *)d2+offset, current_var->size);
-              #endif
-              return 1;
-            }
-          }
-        } 
-        i++;
-      }
-      
+    for(i=0; i<type->element_count; i++){
+      res = compare_areas_with_type((char *)area1 + (i*elm_size), (char *)area2 + (i*elm_size), snapshot1, snapshot2, type->subtype, region_size, region_type, start_data, pointer_level);
+      if(res == 1)
+        return res;
     }
-  }
+    break;
+  case DW_TAG_pointer_type:
+  case DW_TAG_reference_type:
+  case DW_TAG_rvalue_reference_type:
 
-  return 0;
-}
+    addr_pointed1 = *((void **)(area1));
+    addr_pointed2 = *((void **)(area2));
 
-static int heap_region_compare(void *d1, void *d2, size_t size){
-  
-  size_t i = 0;
-  
-  for(i=0; i<size; i++){
-    if(memcmp(((char *)d1) + i, ((char *)d2) + i, 1) != 0){
-      if(XBT_LOG_ISENABLED(mc_compare, xbt_log_priority_verbose)){
-        XBT_VERB("Different byte (offset=%zu) (%p - %p) in heap region", i, (char *)d1 + i, (char *)d2 + i);
+    if(type->subtype && type->subtype->type == DW_TAG_subroutine_type){
+      return (addr_pointed1 != addr_pointed2);
+    }else{
+      
+      if(addr_pointed1 == NULL && addr_pointed2 == NULL)
+        return 0;
+      if(!add_compared_pointers(addr_pointed1, addr_pointed2))
+        return 0;
+
+      pointer_level++;
+      
+      // Some cases are not handled here:
+      // * the pointers lead to different areas (one to the heap, the other to the RW segment ...);
+      // * a pointer leads to the read-only segment of the current object;
+      // * a pointer lead to a different ELF object.
+
+      // The pointers are both in the heap:
+      if(addr_pointed1 > std_heap && (char *)addr_pointed1 < (char*) std_heap + STD_HEAP_SIZE){
+        if(!(addr_pointed2 > std_heap && (char *)addr_pointed2 < (char*) std_heap + STD_HEAP_SIZE))
+          return 1;
+        return compare_heap_area(addr_pointed1, addr_pointed2, snapshot1, snapshot2, NULL, type->subtype, pointer_level);
+      }
+
+      // The pointers are both in the current object R/W segment:
+      else if(addr_pointed1 > start_data && (char*)addr_pointed1 <= (char *)start_data + region_size){
+        if(!(addr_pointed2 > start_data && (char*)addr_pointed2 <= (char *)start_data + region_size))
+          return 1;
+        if(type->dw_type_id == NULL)
+          return  (addr_pointed1 != addr_pointed2);
+        else {
+          void* translated_addr_pointer1 = mc_translate_address((uintptr_t)addr_pointed1, snapshot1);
+          void* translated_addr_pointer2 = mc_translate_address((uintptr_t)addr_pointed2, snapshot2);
+          return  compare_areas_with_type(
+            translated_addr_pointer1, translated_addr_pointer2, snapshot1, snapshot2, type->subtype, region_size, region_type, start_data, pointer_level);
+        }
+      }
+
+      else{
+        return (addr_pointed1 != addr_pointed2);
       }
-      return 1;
     }
+    break;
+  case DW_TAG_structure_type:
+  case DW_TAG_class_type:
+    xbt_dynar_foreach(type->members, cursor, member){
+      XBT_DEBUG("Compare member %s", member->name);
+      void* member1 = mc_member_snapshot_resolve(area1, type, member, snapshot1);
+      void* member2 = mc_member_snapshot_resolve(area2, type, member, snapshot2);
+      res = compare_areas_with_type(member1, member2, snapshot1, snapshot2, member->subtype, region_size, region_type, start_data, pointer_level);
+      if(res == 1)
+        return res;
+    }
+    break;
+  case DW_TAG_subroutine_type:
+    return -1;
+    break;
+  default:
+    XBT_VERB("Unknown case : %d", type->type);
+    break;
   }
   
   return 0;
 }
 
-static void stack_region_free(stack_region_t s){
-  if(s){
-    xbt_free(s->process_name);
-    xbt_free(s);
+static int compare_global_variables(int region_type, mc_mem_region_t r1, mc_mem_region_t r2, mc_snapshot_t snapshot1, mc_snapshot_t snapshot2){
+
+  if(!compared_pointers){
+    compared_pointers = xbt_dynar_new(sizeof(pointers_pair_t), pointers_pair_free_voidp);
+  }else{
+    xbt_dynar_reset(compared_pointers);
   }
-}
 
-void stack_region_free_voidp(void *s){
-  stack_region_free((stack_region_t) * (void **) s);
-}
+  xbt_dynar_t variables;
+  int res;
+  unsigned int cursor = 0;
+  dw_variable_t current_var;
+  size_t offset;
+  void *start_data;
+  void* start_data_binary = mc_binary_info->start_rw;
+  void* start_data_libsimgrid = mc_libsimgrid_info->start_rw;
+
+  mc_object_info_t object_info = NULL;
+  mc_object_info_t other_object_info = NULL;
+  if(region_type == 2){
+    object_info = mc_binary_info;
+    other_object_info = mc_libsimgrid_info;
+    start_data = start_data_binary;
+  }else{
+    object_info = mc_libsimgrid_info;
+    other_object_info = mc_binary_info;
+    start_data = start_data_libsimgrid;
+  }
+  variables = object_info->global_variables;
+
+  xbt_dynar_foreach(variables, cursor, current_var){
+
+    // If the variable is not in this object, skip it:
+    // We do not expect to find a pointer to something which is not reachable
+    // by the global variables.
+    if((char*) current_var->address < (char*) object_info->start_rw
+      || (char*) current_var->address > (char*) object_info->end_rw)
+       continue;
+
+    offset = (char *)current_var->address - (char *)object_info->start_rw;
+
+    dw_type_t bvariable_type = current_var->type;
+    res = compare_areas_with_type((char *)r1->data + offset, (char *)r2->data + offset, snapshot1, snapshot2, bvariable_type, r1->size, region_type, start_data, 0);
+    if(res == 1){
+      XBT_VERB("Global variable %s (%p - %p) is different between snapshots", current_var->name, (char *)r1->data + offset, (char *)r2->data + offset);
+      xbt_dynar_free(&compared_pointers);
+      compared_pointers = NULL;
+      return 1;
+    }
 
-static void heap_equality_free(heap_equality_t e){
-  if(e){
-    xbt_free(e);
   }
-}
 
-void heap_equality_free_voidp(void *e){
-  heap_equality_free((heap_equality_t) * (void **) e);
-}
+  xbt_dynar_free(&compared_pointers);
+  compared_pointers = NULL;
+
+  return 0;
 
-int SIMIX_pre_mc_compare_snapshots(smx_simcall_t simcall,
-                                   mc_snapshot_t s1, mc_snapshot_t s2){
-  return snapshot_compare(s1, s2);
 }
 
-int get_heap_region_index(mc_snapshot_t s){
-  int i = 0;
-  while(i < s->num_reg){
-    switch(s->regions[i]->type){
-    case 0:
-      return i;
-      break;
-    default:
-      i++;
-      break;
+static int compare_local_variables(mc_snapshot_t snapshot1, mc_snapshot_t snapshot2, mc_snapshot_stack_t stack1, mc_snapshot_stack_t stack2, void *heap1, void *heap2){
+  void* start_data_binary = mc_binary_info->start_rw;
+  void* start_data_libsimgrid = mc_libsimgrid_info->start_rw;
+
+  if(!compared_pointers){
+    compared_pointers = xbt_dynar_new(sizeof(pointers_pair_t), pointers_pair_free_voidp);
+  }else{
+    xbt_dynar_reset(compared_pointers);
+  }
+
+  if(xbt_dynar_length(stack1->local_variables) != xbt_dynar_length(stack2->local_variables)){
+    XBT_VERB("Different number of local variables");
+    xbt_dynar_free(&compared_pointers);
+    compared_pointers = NULL;
+    return 1;
+  }else{
+    unsigned int cursor = 0;
+    local_variable_t current_var1, current_var2;
+    int offset1, offset2, res;
+    while(cursor < xbt_dynar_length(stack1->local_variables)){
+      current_var1 = (local_variable_t)xbt_dynar_get_as(stack1->local_variables, cursor, local_variable_t);
+      current_var2 = (local_variable_t)xbt_dynar_get_as(stack2->local_variables, cursor, local_variable_t);
+      if(strcmp(current_var1->name, current_var2->name) != 0 || strcmp(current_var1->frame, current_var2->frame) != 0 || current_var1->ip != current_var2->ip){
+        xbt_dynar_free(&compared_pointers);
+        XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name, current_var2->name, current_var1->frame, current_var2->frame, current_var1->ip, current_var2->ip);
+        return 1;
+      }
+      offset1 = (char *)current_var1->address - (char *)std_heap;
+      offset2 = (char *)current_var2->address - (char *)std_heap;
+      XBT_DEBUG("Compare local variable %s of frame %s", current_var1->name, current_var1->frame);
+
+
+      if(current_var1->region == 1) {
+        dw_type_t subtype = current_var1->type;
+        res = compare_areas_with_type( (char *)heap1 + offset1, (char *)heap2 + offset2, snapshot1, snapshot2, subtype, 0, 1, start_data_libsimgrid, 0);
+      } else {
+        dw_type_t subtype = current_var2->type;
+        res = compare_areas_with_type( (char *)heap1 + offset1, (char *)heap2 + offset2, snapshot1, snapshot2, subtype, 0, 2, start_data_binary, 0);
+      }
+      if(res == 1){
+        XBT_VERB("Local variable %s (%p - %p) in frame %s  is different between snapshots", current_var1->name,(char *)heap1 + offset1, (char *)heap2 + offset2, current_var1->frame);
+        xbt_dynar_free(&compared_pointers);
+        compared_pointers = NULL;
+        return res;
+      }
+      cursor++;
     }
+    xbt_dynar_free(&compared_pointers);
+    compared_pointers = NULL;
+    return 0;
   }
-  return -1;
 }
 
-int snapshot_compare(mc_snapshot_t s1, mc_snapshot_t s2){
+int snapshot_compare(void *state1, void *state2){
 
-  int raw_mem = (mmalloc_get_current_heap() == raw_heap);
+  mc_snapshot_t s1, s2;
+  int num1, num2;
   
-  MC_SET_RAW_MEM;
-     
+  if(_sg_mc_property_file && _sg_mc_property_file[0] != '\0'){ /* Liveness MC */
+    s1 = ((mc_visited_pair_t)state1)->graph_state->system_state;
+    s2 = ((mc_visited_pair_t)state2)->graph_state->system_state;
+    num1 = ((mc_visited_pair_t)state1)->num;
+    num2 =  ((mc_visited_pair_t)state2)->num;
+    /* Firstly compare automaton state */
+    /*if(xbt_automaton_state_compare(((mc_pair_t)state1)->automaton_state, ((mc_pair_t)state2)->automaton_state) != 0)
+      return 1;
+    if(xbt_automaton_propositional_symbols_compare_value(((mc_pair_t)state1)->atomic_propositions, ((mc_pair_t)state2)->atomic_propositions) != 0)
+    return 1;*/
+  }else{ /* Safety MC */
+    s1 = ((mc_visited_state_t)state1)->system_state;
+    s2 = ((mc_visited_state_t)state2)->system_state;
+    num1 = ((mc_visited_state_t)state1)->num;
+    num2 = ((mc_visited_state_t)state2)->num;
+  }
+
   int errors = 0;
+  int res_init;
 
   xbt_os_timer_t global_timer = xbt_os_timer_new();
   xbt_os_timer_t timer = xbt_os_timer_new();
 
-  xbt_os_timer_start(global_timer);
+  xbt_os_walltimer_start(global_timer);
 
   #ifdef MC_DEBUG
-    xbt_os_timer_start(timer);
+    xbt_os_walltimer_start(timer);
   #endif
 
-  /* Compare number of processes */
-  if(s1->nb_processes != s2->nb_processes){
-    #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
-      mc_comp_times->nb_processes_comparison_time =  xbt_os_timer_elapsed(timer);
-      XBT_DEBUG("Different number of processes : %d - %d", s1->nb_processes, s2->nb_processes);
-      errors++;
-    #else
-      #ifdef MC_VERBOSE
-        XBT_VERB("Different number of processes : %d - %d", s1->nb_processes, s2->nb_processes);
-      #endif
-     
-      xbt_os_timer_free(timer);
-      xbt_os_timer_stop(global_timer);
-      mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
-      xbt_os_timer_free(global_timer);
-
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
-
+  int hash_result = 0;
+  if(_sg_mc_hash) {
+    hash_result = (s1->hash != s2->hash);
+    if(hash_result) {
+      XBT_VERB("(%d - %d) Different hash : 0x%" PRIx64 "--0x%" PRIx64, num1, num2, s1->hash, s2->hash);
+#ifndef MC_DEBUG
       return 1;
-    #endif
+#endif
+    } else {
+      XBT_VERB("(%d - %d) Same hash : 0x%" PRIx64, num1, num2, s1->hash);
+    }
   }
 
-  /* Compare number of blocks/fragments used in each heap */
-  if(s1->heap_chunks_used != s2->heap_chunks_used){
-    #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
-      mc_comp_times->chunks_used_comparison_time = xbt_os_timer_elapsed(timer);
-      XBT_DEBUG("Different number of chunks used in each heap : %zu - %zu", s1->heap_chunks_used, s2->heap_chunks_used);
-      errors++;
-    #else
-      #ifdef MC_VERBOSE
-        XBT_VERB("Different number of chunks used in each heap : %zu - %zu", s1->heap_chunks_used, s2->heap_chunks_used);
-      #endif
-
-      xbt_os_timer_free(timer);
-      xbt_os_timer_stop(global_timer);
-      mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
-      xbt_os_timer_free(global_timer);
-
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
-
-      return 1;
-    #endif
-  }else{
-    #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
-    #endif
-  }
-  
-  #ifdef MC_DEBUG
-    xbt_os_timer_start(timer);
-  #endif
-  
-  /* Compare size of stacks */
   int i = 0;
   size_t size_used1, size_used2;
   int is_diff = 0;
+
+
+  /* Compare size of stacks */
   while(i < xbt_dynar_length(s1->stacks)){
     size_used1 = s1->stack_sizes[i];
     size_used2 = s2->stack_sizes[i];
     if(size_used1 != size_used2){
     #ifdef MC_DEBUG
       if(is_diff == 0){
-        xbt_os_timer_stop(timer);
+        xbt_os_walltimer_stop(timer);
         mc_comp_times->stacks_sizes_comparison_time = xbt_os_timer_elapsed(timer);
       }
-      XBT_DEBUG("Different size used in stacks : %zu - %zu", size_used1, size_used2);
+      XBT_DEBUG("(%d - %d) Different size used in stacks : %zu - %zu", num1, num2, size_used1, size_used2);
       errors++;
       is_diff = 1;
     #else
       #ifdef MC_VERBOSE
-        XBT_VERB("Different size used in stacks : %zu - %zu", size_used1, size_used2);
+      XBT_VERB("(%d - %d) Different size used in stacks : %zu - %zu", num1, num2, size_used1, size_used2);
       #endif
- 
+
+      xbt_os_walltimer_stop(timer);
       xbt_os_timer_free(timer);
-      xbt_os_timer_stop(global_timer);
+      xbt_os_walltimer_stop(global_timer);
       mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
       xbt_os_timer_free(global_timer);
 
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
-
       return 1;
     #endif  
     }
@@ -294,190 +423,156 @@ int snapshot_compare(mc_snapshot_t s1, mc_snapshot_t s2){
 
   #ifdef MC_DEBUG
     if(is_diff == 0)
-      xbt_os_timer_stop(timer);
-    xbt_os_timer_start(timer);
+      xbt_os_walltimer_stop(timer);
+    xbt_os_walltimer_start(timer);
   #endif
 
-  int heap_index = 0, data_libsimgrid_index = 0, data_program_index = 0;
-  i = 0;
-  
-  /* Get index of regions */
-  while(i < s1->num_reg){
-    switch(s1->region_type[i]){
-    case 0:
-      heap_index = i;
-      i++;
-      break;
-    case 1:
-      data_libsimgrid_index = i;
-      i++;
-      while( i < s1->num_reg && s1->region_type[i] == 1)
-        i++;
-      break;
-    case 2:
-      data_program_index = i;
-      i++;
-      while( i < s1->num_reg && s1->region_type[i] == 2)
-        i++;
-      break;
-    }
-  }
-
   /* Init heap information used in heap comparison algorithm */
-  init_heap_information((xbt_mheap_t)s1->regions[heap_index]->data, (xbt_mheap_t)s2->regions[heap_index]->data);
+  res_init = init_heap_information((xbt_mheap_t)s1->regions[0]->data, (xbt_mheap_t)s2->regions[0]->data, s1->to_ignore, s2->to_ignore);
+  if(res_init == -1){
+     #ifdef MC_DEBUG
+    XBT_DEBUG("(%d - %d) Different heap information", num1, num2); 
+        errors++; 
+      #else
+        #ifdef MC_VERBOSE
+        XBT_VERB("(%d - %d) Different heap information", num1, num2); 
+        #endif
 
-  xbt_dynar_t equals = xbt_dynar_new(sizeof(heap_equality_t), heap_equality_free_voidp);
+        xbt_os_walltimer_stop(global_timer);
+        mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
+        xbt_os_timer_free(global_timer);
 
-  /* Compare binary global variables */
-  is_diff = compare_global_variables(s1->region_type[data_program_index], s1->regions[data_program_index]->data, s2->regions[data_program_index]->data, equals);
-  if(is_diff != 0){
-    #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
-      mc_comp_times->binary_global_variables_comparison_time = xbt_os_timer_elapsed(timer);
-      XBT_DEBUG("Different global variables in binary"); 
-      errors++; 
-    #else
-      #ifdef MC_VERBOSE
-        XBT_VERB("Different global variables in binary"); 
+        return 1;
       #endif
-    
-      xbt_os_timer_free(timer);
-      xbt_os_timer_stop(global_timer);
-      mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
-      xbt_os_timer_free(global_timer);
-    
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
-
-      return 1;
-    #endif
   }
 
-  #ifdef MC_VERBOSE
-    if(is_diff == 0)
-      xbt_os_timer_stop(timer);
-    xbt_os_timer_start(timer);
+  #ifdef MC_DEBUG
+    xbt_os_walltimer_start(timer);
   #endif
 
-  /* Compare libsimgrid global variables */
-    is_diff = compare_global_variables(s1->region_type[data_libsimgrid_index], s1->regions[data_libsimgrid_index]->data, s2->regions[data_libsimgrid_index]->data, equals);
+  /* Stacks comparison */
+  unsigned int  cursor = 0;
+  int diff_local = 0;
+  is_diff = 0;
+  mc_snapshot_stack_t stack1, stack2;
+    
+  while(cursor < xbt_dynar_length(s1->stacks)){
+    stack1 = (mc_snapshot_stack_t)xbt_dynar_get_as(s1->stacks, cursor, mc_snapshot_stack_t);
+    stack2 = (mc_snapshot_stack_t)xbt_dynar_get_as(s2->stacks, cursor, mc_snapshot_stack_t);
+    diff_local = compare_local_variables(s1, s2, stack1, stack2, s1->regions[0]->data, s2->regions[0]->data);
+    if(diff_local > 0){
+      #ifdef MC_DEBUG
+        if(is_diff == 0){
+          xbt_os_walltimer_stop(timer);
+          mc_comp_times->stacks_comparison_time = xbt_os_timer_elapsed(timer);
+        }
+        XBT_DEBUG("(%d - %d) Different local variables between stacks %d", num1, num2, cursor + 1);
+        errors++;
+        is_diff = 1;
+      #else
+        
+        #ifdef MC_VERBOSE
+        XBT_VERB("(%d - %d) Different local variables between stacks %d", num1, num2, cursor + 1);
+        #endif
+          
+        reset_heap_information();
+        xbt_os_walltimer_stop(timer);
+        xbt_os_timer_free(timer);
+        xbt_os_walltimer_stop(global_timer);
+        mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
+        xbt_os_timer_free(global_timer);
+ 
+        return 1;
+      #endif
+    }
+    cursor++;
+  }
+
+
+
+ const char* names[3] = { "?", "libsimgrid", "binary" };
+#ifdef MC_DEBUG
+ double *times[3] = {
+   NULL,
+   &mc_comp_times->libsimgrid_global_variables_comparison_time,
+   &mc_comp_times->binary_global_variables_comparison_time
+ };
+#endif
+
+ int k=0;
+ for(k=2; k!=0; --k) {
+    #ifdef MC_DEBUG
+      if(is_diff == 0)
+        xbt_os_walltimer_stop(timer);
+      xbt_os_walltimer_start(timer);
+    #endif
+
+  /* Compare global variables */
+  is_diff = compare_global_variables(k, s1->regions[k], s2->regions[k], s1, s2);
   if(is_diff != 0){
     #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
-      mc_comp_times->libsimgrid_global_variables_comparison_time = xbt_os_timer_elapsed(timer); 
-      XBT_DEBUG("Different global variables in libsimgrid"); 
-      errors++; 
+      xbt_os_walltimer_stop(timer);
+      *times[k] = xbt_os_timer_elapsed(timer);
+      XBT_DEBUG("(%d - %d) Different global variables in %s", num1, num2, names[k]);
+      errors++;
     #else
       #ifdef MC_VERBOSE
-        XBT_VERB("Different global variables in libsimgrid"); 
+      XBT_VERB("(%d - %d) Different global variables in %s", num1, num2, names[k]);
       #endif
-    
+
+      reset_heap_information();
+      xbt_os_walltimer_stop(timer);
       xbt_os_timer_free(timer);
-      xbt_os_timer_stop(global_timer);
+      xbt_os_walltimer_stop(global_timer);
       mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
       xbt_os_timer_free(global_timer);
-    
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
 
       return 1;
     #endif
-  }  
+  }
+ }
 
   #ifdef MC_DEBUG
-    if(is_diff == 0)
-      xbt_os_timer_stop(timer);
-    xbt_os_timer_start(timer);
+    xbt_os_walltimer_start(timer);
   #endif
 
   /* Compare heap */
-  xbt_dynar_t stacks1 = xbt_dynar_new(sizeof(stack_region_t), stack_region_free_voidp);
-  xbt_dynar_t stacks2 = xbt_dynar_new(sizeof(stack_region_t), stack_region_free_voidp);
- 
-  if(mmalloc_compare_heap((xbt_mheap_t)s1->regions[heap_index]->data, (xbt_mheap_t)s2->regions[heap_index]->data, &stacks1, &stacks2, equals)){
+    if(mmalloc_compare_heap(s1, s2, (xbt_mheap_t)s1->regions[0]->data,
+                            (xbt_mheap_t)s2->regions[0]->data) > 0){
 
     #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
+      xbt_os_walltimer_stop(timer);
       mc_comp_times->heap_comparison_time = xbt_os_timer_elapsed(timer); 
-      XBT_DEBUG("Different heap (mmalloc_compare)");
+      XBT_DEBUG("(%d - %d) Different heap (mmalloc_compare)", num1, num2);
       errors++;
     #else
-
-      xbt_os_timer_free(timer);
-      xbt_dynar_free(&stacks1);
-      xbt_dynar_free(&stacks2);
-      xbt_dynar_free(&equals);
  
       #ifdef MC_VERBOSE
-        XBT_VERB("Different heap (mmalloc_compare)");
+      XBT_VERB("(%d - %d) Different heap (mmalloc_compare)", num1, num2);
       #endif
        
-      xbt_os_timer_stop(global_timer);
+      reset_heap_information();
+      xbt_os_walltimer_stop(timer);
+      xbt_os_timer_free(timer);
+      xbt_os_walltimer_stop(global_timer);
       mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
       xbt_os_timer_free(global_timer);
 
-      if(!raw_mem)
-        MC_UNSET_RAW_MEM;
-
       return 1;
     #endif
   }else{
     #ifdef MC_DEBUG
-      xbt_os_timer_stop(timer);
+      xbt_os_walltimer_stop(timer);
     #endif
   }
 
-  #ifdef MC_DEBUG
-    xbt_os_timer_start(timer);
-  #endif
-
-  /* Stacks comparison */
-  unsigned int  cursor = 0;
-  int diff_local = 0;
-  is_diff = 0;
-
-  while(cursor < xbt_dynar_length(stacks1)){
-    diff_local = compare_local_variables(((mc_snapshot_stack_t)xbt_dynar_get_as(s1->stacks, cursor, mc_snapshot_stack_t))->local_variables->data, ((mc_snapshot_stack_t)xbt_dynar_get_as(s2->stacks, cursor, mc_snapshot_stack_t))->local_variables->data, equals);
-    if(diff_local > 0){
-      #ifdef MC_DEBUG
-        if(is_diff == 0){
-          xbt_os_timer_stop(timer);
-          mc_comp_times->stacks_comparison_time = xbt_os_timer_elapsed(timer); 
-        }
-        XBT_DEBUG("Different local variables between stacks %d", cursor + 1);
-        errors++;
-        is_diff = 1;
-      #else
-        xbt_dynar_free(&stacks1);
-        xbt_dynar_free(&stacks2);
-        xbt_dynar_free(&equals);
-        
-      #ifdef MC_VERBOSE
-        XBT_VERB("Different local variables between stacks %d", cursor + 1);
-      #endif
-          
-        xbt_os_timer_free(timer);
-        xbt_os_timer_stop(global_timer);
-        mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
-        xbt_os_timer_free(global_timer);
-        
-        if(!raw_mem)
-          MC_UNSET_RAW_MEM;
-        
-        return 1;
-      #endif
-    }
-    cursor++;
-  }
-
-  xbt_dynar_free(&stacks1);
-  xbt_dynar_free(&stacks2);
-  xbt_dynar_free(&equals);
-   
+  reset_heap_information();
+  
+  xbt_os_walltimer_stop(timer);
   xbt_os_timer_free(timer);
 
   #ifdef MC_VERBOSE
-    xbt_os_timer_stop(global_timer);
+    xbt_os_walltimer_stop(global_timer);
     mc_snapshot_comparison_time = xbt_os_timer_elapsed(global_timer);
   #endif
 
@@ -487,172 +582,52 @@ int snapshot_compare(mc_snapshot_t s1, mc_snapshot_t s2){
     print_comparison_times();
   #endif
 
-  if(!raw_mem)
-    MC_UNSET_RAW_MEM;
-
-  return errors > 0;
-  
-}
-
-static int is_stack_ignore_variable(char *frame, char *var_name){
-
-  unsigned int cursor = 0;
-  int start = 0;
-  int end = xbt_dynar_length(mc_stack_comparison_ignore) - 1;
-  mc_stack_ignore_variable_t current_var;
-
-  while(start <= end){
-    cursor = (start + end) / 2;
-    current_var = (mc_stack_ignore_variable_t)xbt_dynar_get_as(mc_stack_comparison_ignore, cursor, mc_stack_ignore_variable_t);
-    if(strcmp(current_var->frame, frame) == 0 || strcmp(current_var->frame, "*") == 0){
-      if(strcmp(current_var->var_name, var_name) == 0)
-        return 1;
-      if(strcmp(current_var->var_name, var_name) < 0)
-        start = cursor + 1;
-      if(strcmp(current_var->var_name, var_name) > 0)
-        end = cursor - 1;
-    }else if(strcmp(current_var->frame, frame) < 0){
-      start = cursor + 1;
-    }else if(strcmp(current_var->frame, frame) > 0){
-      end = cursor - 1; 
-    }
-  }
-
-  return 0;
-}
-
-static int compare_local_variables(char *s1, char *s2, xbt_dynar_t heap_equals){
-  
-  xbt_dynar_t tokens1 = xbt_str_split(s1, NULL);
-  xbt_dynar_t tokens2 = xbt_str_split(s2, NULL);
-
-  xbt_dynar_t s_tokens1, s_tokens2;
-  unsigned int cursor = 0;
-  void *addr1, *addr2;
-  char *ip1 = NULL, *ip2 = NULL;
-  
-  while(cursor < xbt_dynar_length(tokens1)){
-    s_tokens1 = xbt_str_split(xbt_dynar_get_as(tokens1, cursor, char *), "=");
-    s_tokens2 = xbt_str_split(xbt_dynar_get_as(tokens2, cursor, char *), "=");
-    if(xbt_dynar_length(s_tokens1) > 1 && xbt_dynar_length(s_tokens2) > 1){
-      if((strcmp(xbt_dynar_get_as(s_tokens1, 0, char *), "ip") == 0) && (strcmp(xbt_dynar_get_as(s_tokens2, 0, char *), "ip") == 0)){
-        xbt_free(ip1);
-        xbt_free(ip2);
-        ip1 = strdup(xbt_dynar_get_as(s_tokens1, 1, char *));
-        ip2 = strdup(xbt_dynar_get_as(s_tokens2, 1, char *));
-      }
-      if(strcmp(xbt_dynar_get_as(s_tokens1, 1, char *), xbt_dynar_get_as(s_tokens2, 1, char *)) != 0){   
-        /* Ignore this variable ?  */
-        if(is_stack_ignore_variable(ip1, xbt_dynar_get_as(s_tokens1, 0, char *)) && is_stack_ignore_variable(ip2, xbt_dynar_get_as(s_tokens2, 0, char *))){
-          xbt_dynar_free(&s_tokens1);
-          xbt_dynar_free(&s_tokens2);
-          cursor++;
-          continue;
-        }
-        addr1 = (void *) strtoul(xbt_dynar_get_as(s_tokens1, 1, char *), NULL, 16);
-        addr2 = (void *) strtoul(xbt_dynar_get_as(s_tokens2, 1, char *), NULL, 16);
-        if(is_heap_equality(heap_equals, addr1, addr2) == 0){
-          if(XBT_LOG_ISENABLED(mc_compare, xbt_log_priority_verbose))
-            XBT_VERB("Variable %s is different between stacks in %s : %s - %s", xbt_dynar_get_as(s_tokens1, 0, char *), ip1, xbt_dynar_get_as(s_tokens1, 1, char *), xbt_dynar_get_as(s_tokens2, 1, char *));
-          xbt_dynar_free(&s_tokens1);
-          xbt_dynar_free(&s_tokens2);
-          xbt_dynar_free(&tokens1);
-          xbt_dynar_free(&tokens2);
-          xbt_free(ip1);
-          xbt_free(ip2);
-          return 1;
-        }
-      }
-    }
-    xbt_dynar_free(&s_tokens1);
-    xbt_dynar_free(&s_tokens2);
-         
-    cursor++;
-  }
-
-  xbt_free(ip1);
-  xbt_free(ip2);
-  xbt_dynar_free(&tokens1);
-  xbt_dynar_free(&tokens2);
-  return 0;
+#ifdef MC_VERBOSE
+   if(errors || hash_result)
+     XBT_VERB("(%d - %d) Difference found", num1, num2);
+   else
+     XBT_VERB("(%d - %d) No difference found", num1, num2);
+#endif
+
+#if defined(MC_DEBUG) && defined(MC_VERBOSE)
+   if(_sg_mc_hash) {
+     // * false positive SHOULD be avoided.
+     // * There MUST not be any false negative.
+
+     XBT_VERB("(%d - %d) State equality hash test is %s %s", num1, num2,
+       (hash_result!=0) == (errors!=0) ? "true" : "false",
+       !hash_result ? "positive" : "negative");
+   }
+#endif
+
+   return errors > 0 || hash_result;
   
 }
 
-static int is_heap_equality(xbt_dynar_t equals, void *a1, void *a2){
-
-  unsigned int cursor = 0;
-  int start = 0;
-  int end = xbt_dynar_length(equals) - 1;
-  heap_equality_t current_equality;
-
-  while(start <= end){
-    cursor = (start + end) / 2;
-    current_equality = (heap_equality_t)xbt_dynar_get_as(equals, cursor, heap_equality_t);
-    if(current_equality->address1 == a1){
-      if(current_equality->address2 == a2)
-        return 1;
-      if(current_equality->address2 < a2)
-        start = cursor + 1;
-      if(current_equality->address2 > a2)
-        end = cursor - 1;
-    }
-    if(current_equality->address1 < a1)
-      start = cursor + 1;
-    if(current_equality->address1 > a1)
-      end = cursor - 1; 
-  }
-
-  return 0;
+/***************************** Statistics *****************************/
+/*******************************************************************/
 
+void print_comparison_times(){
+  XBT_DEBUG("*** Comparison times ***");
+  XBT_DEBUG("- Nb processes : %f", mc_comp_times->nb_processes_comparison_time);
+  XBT_DEBUG("- Nb bytes used : %f", mc_comp_times->bytes_used_comparison_time);
+  XBT_DEBUG("- Stacks sizes : %f", mc_comp_times->stacks_sizes_comparison_time);
+  XBT_DEBUG("- Binary global variables : %f", mc_comp_times->binary_global_variables_comparison_time);
+  XBT_DEBUG("- Libsimgrid global variables : %f", mc_comp_times->libsimgrid_global_variables_comparison_time);
+  XBT_DEBUG("- Heap : %f", mc_comp_times->heap_comparison_time);
+  XBT_DEBUG("- Stacks : %f", mc_comp_times->stacks_comparison_time);
 }
 
+/**************************** MC snapshot compare simcall **************************/
+/***********************************************************************************/
 
-static int compare_stack(stack_region_t s1, stack_region_t s2, void *sp1, void *sp2, void *heap1, void *heap2, xbt_dynar_t equals){
-  
-  size_t k = 0;
-  size_t size_used1 = s1->size - ((char*)sp1 - (char*)s1->address);
-  size_t size_used2 = s2->size - ((char*)sp2 - (char*)s2->address);
-
-  int pointer_align;
-  void *addr_pointed1 = NULL, *addr_pointed2 = NULL;  
-  
-  while(k < size_used1){
-    if(memcmp((char *)s1->address + s1->size - k, (char *)s2->address + s2->size - k, 1) != 0){
-      pointer_align = ((size_used1 - k) / sizeof(void*)) * sizeof(void*);
-      addr_pointed1 = *((void **)(((char*)s1->address + (s1->size - size_used1)) + pointer_align));
-      addr_pointed2 = *((void **)(((char*)s2->address + (s2->size - size_used2)) + pointer_align));
-      if(is_heap_equality(equals, addr_pointed1, addr_pointed2) == 0){
-        if((addr_pointed1 > std_heap) && (addr_pointed1 < (void *)((char *)std_heap + STD_HEAP_SIZE)) && (addr_pointed2 > std_heap) && (addr_pointed2 < (void *)((char *)std_heap + STD_HEAP_SIZE))){
-          if(is_free_area(addr_pointed1, (xbt_mheap_t)heap1) == 0 || is_free_area(addr_pointed2, (xbt_mheap_t)heap2) == 0){
-            return 1;
-          }
-        }else{
-          return 1;
-        } 
-      }
-    } 
-    k++;
-  }
- 
-  return 0;
+int SIMIX_pre_mc_compare_snapshots(smx_simcall_t simcall,
+                                   mc_snapshot_t s1, mc_snapshot_t s2){
+  return snapshot_compare(s1, s2);
 }
 
 int MC_compare_snapshots(void *s1, void *s2){
-  
-  MC_ignore_stack("self", "simcall_BODY_mc_snapshot");
-  MC_ignore_stack("i", "simcall_BODY_mc_snapshot");
 
   return simcall_mc_compare_snapshots(s1, s2);
 
 }
-
-void print_comparison_times(){
-  XBT_DEBUG("*** Comparison times ***");
-  XBT_DEBUG("- Nb processes : %f", mc_comp_times->nb_processes_comparison_time);
-  XBT_DEBUG("- Nb chunks used : %f", mc_comp_times->chunks_used_comparison_time);
-  XBT_DEBUG("- Stacks sizes : %f", mc_comp_times->stacks_sizes_comparison_time);
-  XBT_DEBUG("- Binary global variables : %f", mc_comp_times->binary_global_variables_comparison_time);
-  XBT_DEBUG("- Libsimgrid global variables : %f", mc_comp_times->libsimgrid_global_variables_comparison_time);
-  XBT_DEBUG("- Heap : %f", mc_comp_times->heap_comparison_time);
-  XBT_DEBUG("- Stacks : %f", mc_comp_times->stacks_comparison_time);
-}