X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/c39a26c5592bf2636300ebbe1a996c9c3736d07e..5fb2fa67ea062d8c26cfe3e6669a93fc2b7607bd:/src/gras/DataDesc/ddt_create.c

diff --git a/src/gras/DataDesc/ddt_create.c b/src/gras/DataDesc/ddt_create.c
index 630da1808a..5dfcdea030 100644
--- a/src/gras/DataDesc/ddt_create.c
+++ b/src/gras/DataDesc/ddt_create.c
@@ -14,6 +14,10 @@
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ddt_create,datadesc,"Creating new datadescriptions");
 
+/*** prototypes ***/
+static gras_dd_cat_field_t
+  gras_dd_find_field(gras_datadesc_type_t  type,
+		     const char           *field_name);
 /**
  * gras_ddt_freev:
  *
@@ -44,9 +48,7 @@ static gras_datadesc_type_t gras_ddt_new(const char *name) {
 }
 
 /**
- * gras_datadesc_by_name:
- *
- * Retrieve a type from its name
+ * This returns NULL when no type of this name can be found
  */
 gras_datadesc_type_t gras_datadesc_by_name(const char *name) {
 
@@ -64,8 +66,6 @@ gras_datadesc_type_t gras_datadesc_by_name(const char *name) {
 }
 
 /**
- * gras_datadesc_by_id:
- *
  * Retrieve a type from its code
  */
 xbt_error_t gras_datadesc_by_id(long int              code,
@@ -76,8 +76,6 @@ xbt_error_t gras_datadesc_by_id(long int              code,
 }
 
 /**
- * gras_datadesc_scalar:
- *
  * Create a new scalar and give a pointer to it 
  */
 gras_datadesc_type_t 
@@ -103,44 +101,9 @@ gras_datadesc_type_t
   res = gras_ddt_new(name);
 
   for (arch = 0; arch < gras_arch_count; arch ++) {
-#if 0
-    long int sz;
-    long int mask;
-#endif
     res->size[arch]         = gras_arches[arch].sizeofs[type];
     res->alignment[arch]    = gras_arches[arch].boundaries[type];
     res->aligned_size[arch] = aligned(res->size[arch], res->alignment[arch]);
-/* FIXME: kill the following after discution with Oli */
-#if 0
-    sz = res->size[arch];
-    mask = sz;
-    
-    /* just in case you wonder, x>>1 == x/2 on all architectures when x>=0
-       and a size is always>=0 */
-    
-    /* make sure mask have all the bits under the biggest one of size set to 1
-       Example: size=000100101 => mask=0000111111 */
-    while ((sz >>= 1)) {
-      mask |= sz;
-    } 
-    
-    if (res->size[arch] & (mask >> 1)) { /* if size have bits to one beside its biggest */
-      /* size is not a power of 2 */
-      /* alignment= next power of 2 after size */
-      res->alignment[arch] = (res->size[arch] & ~(mask >> 1)) << 1;
-      xbt_assert0(res->alignment[arch] != 0,
-		   "scalar type too large");
-      
-      res->aligned_size[arch] = aligned(res->size[arch], res->alignment[arch]);
-      xbt_assert0 (res->aligned_size[arch] >= 0,
-		    "scalar type too large");
-      
-    } else {
-      /* size is a power of 2, life is great */
-      res->alignment[arch]       = res->size[arch];
-      res->aligned_size[arch]    = res->size[arch];
-    }
-#endif     
   }
 
   res->category_code                 = e_gras_datadesc_type_cat_scalar;
@@ -152,27 +115,19 @@ gras_datadesc_type_t
 }
 
 
-/**
- * gras_dd_cat_field_free:
- *
- * Frees one struct or union field
- */
+/** Frees one struct or union field */
 void gras_dd_cat_field_free(void *f) {
   gras_dd_cat_field_t field = *(gras_dd_cat_field_t *)f;
   XBT_IN;
   if (field) {
     if (field->name) 
-      xbt_free(field->name);
-    xbt_free(field);
+      free(field->name);
+    free(field);
   }
   XBT_OUT;
 }
 
-/**
- * gras_datadesc_struct:
- *
- * Create a new struct and give a pointer to it 
- */
+/** \brief Declare a new structure description */
 gras_datadesc_type_t 
   gras_datadesc_struct(const char            *name) {
 
@@ -204,11 +159,7 @@ gras_datadesc_type_t
   return res;
 }
 
-/**
- * gras_datadesc_struct_append:
- *
- * Append a field to the struct
- */
+/** \brief Append a new field to a structure description */
 void
 gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
 			    const char          *name,
@@ -252,8 +203,8 @@ gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
 					      struct_type->alignment[arch]);
   }
   field->type   = field_type;
-  field->pre    = NULL;
-  field->post   = NULL;
+  field->send   = NULL;
+  field->recv   = NULL;
   
   xbt_dynar_push(struct_type->category.struct_data.fields, &field);
 
@@ -270,6 +221,10 @@ gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
   XBT_OUT;
 }
 
+/** \brief Close a structure description
+ * 
+ * No new field can be added afterward, and it is mandatory to close the structure before using it.
+ */
 void
 gras_datadesc_struct_close(gras_datadesc_type_t struct_type) {
   XBT_IN;
@@ -284,8 +239,8 @@ gras_datadesc_struct_close(gras_datadesc_type_t struct_type) {
 /**
  * gras_datadesc_cycle_set:
  * 
- * Tell GRAS that the pointers of the type described by @ddt may present
- * some loop, and that the cycle detection mecanism is needed.
+ * Tell GRAS that the pointers of the type described by ddt may present
+ * some loop, and that the cycle detection mechanism is needed.
  *
  * Note that setting this option when not needed have a rather bad effect 
  * on the performance (several times slower on big data).
@@ -294,11 +249,12 @@ void
 gras_datadesc_cycle_set(gras_datadesc_type_t ddt) {
   ddt->cycle = 1;
 }
+
 /**
  * gras_datadesc_cycle_unset:
  * 
- * Tell GRAS that the pointers of the type described by @ddt do not present
- * any loop and that cycle detection mecanism are not needed.
+ * Tell GRAS that the pointers of the type described by ddt do not present
+ * any loop and that cycle detection mechanism are not needed.
  * (default)
  */
 void
@@ -306,14 +262,10 @@ gras_datadesc_cycle_unset(gras_datadesc_type_t ddt) {
   ddt->cycle = 0;
 }
 
-/**
- * gras_datadesc_union:
- *
- * Create a new union and give a pointer to it 
- */
+/** \brief Declare a new union description */
 gras_datadesc_type_t 
-gras_datadesc_union(const char                   *name,
-		    gras_datadesc_type_cb_int_t   selector) {
+  gras_datadesc_union(const char                   *name,
+		      gras_datadesc_type_cb_int_t   selector) {
 
   gras_datadesc_type_t res;
   int arch;
@@ -350,15 +302,10 @@ gras_datadesc_union(const char                   *name,
   return res;
 }
 
-/**
- * gras_datadesc_union_append:
- *
- * Append a field to the union
- */
-void
-gras_datadesc_union_append(gras_datadesc_type_t  union_type,
-			   const char           *name,
-			   gras_datadesc_type_t  field_type) {
+/** \brief Append a new field to an union description */
+void gras_datadesc_union_append(gras_datadesc_type_t  union_type,
+				const char           *name,
+				gras_datadesc_type_t  field_type) {
 
   gras_dd_cat_field_t field;
   int arch;
@@ -392,15 +339,17 @@ gras_datadesc_union_append(gras_datadesc_type_t  union_type,
   }
 }
 
+
+/** \brief Close an union description 
+ *
+ * No new field can be added afterward, and it is mandatory to close the union before using it.
+ */
 void
 gras_datadesc_union_close(gras_datadesc_type_t union_type) {
    union_type->category.union_data.closed = 1;
 }
-/**
- * gras_datadesc_ref:
- *
- * Create a new ref to a fixed type and give a pointer to it 
- */
+
+/** \brief Declare a new type being a reference to the one passed in arg */
 gras_datadesc_type_t 
   gras_datadesc_ref(const char           *name,
 		    gras_datadesc_type_t  referenced_type) {
@@ -438,10 +387,11 @@ gras_datadesc_type_t
 
   return res;
 }
-/**
- * gras_datadesc_ref_generic:
- *
- * Create a new ref to a type given at use time, and give a pointer to it 
+/** \brief Declare a new type being a generic reference.
+ * 
+ * The callback passed in argument is to be used to select which type is currently used.
+ * So, when GRAS wants to send a generic reference, it passes the current data to the selector 
+ * callback and expects it to return the type description to use. 
  */
 gras_datadesc_type_t 
   gras_datadesc_ref_generic(const char                *name,
@@ -481,11 +431,7 @@ gras_datadesc_type_t
   return res;
 }
 
-/**
- * gras_datadesc_array_fixed:
- *
- * Create a new array and give a pointer to it 
- */
+/** \brief Declare a new type being an array of fixed size and content */
 gras_datadesc_type_t 
   gras_datadesc_array_fixed(const char           *name,
 			    gras_datadesc_type_t  element_type,
@@ -499,8 +445,13 @@ gras_datadesc_type_t
   if (res) {
     xbt_assert1(res->category_code == e_gras_datadesc_type_cat_array,
 		 "Redefinition of type %s does not match", name);
-    xbt_assert1(res->category.array_data.type == element_type,
-		 "Redefinition of type %s does not match", name);
+     
+    if (res->category.array_data.type != element_type) {
+       ERROR1("Redefinition of type %s does not match: array elements differ", name);
+       gras_datadesc_type_dump(res->category.array_data.type);
+       gras_datadesc_type_dump(element_type);
+    }
+     
     xbt_assert1(res->category.array_data.fixed_size == fixed_size,
 		 "Redefinition of type %s does not match", name);
     xbt_assert1(res->category.array_data.dynamic_size == NULL,
@@ -526,15 +477,11 @@ gras_datadesc_type_t
 
   return res;
 }
-/**
- * gras_datadesc_array_dyn:
- *
- * Create a new array and give a pointer to it 
- */
-gras_datadesc_type_t 
-  gras_datadesc_array_dyn(const char                  *name,
-			  gras_datadesc_type_t         element_type,
-			  gras_datadesc_type_cb_int_t  dynamic_size) {
+
+/** \brief Declare a new type being an array of fixed size, but accepting several content types. */
+gras_datadesc_type_t gras_datadesc_array_dyn(const char                 *name,
+					     gras_datadesc_type_t        element_type,
+					     gras_datadesc_type_cb_int_t dynamic_size) {
 
   gras_datadesc_type_t res;
   int arch;
@@ -576,9 +523,8 @@ gras_datadesc_type_t
   return res;
 }
 
-/**
- * gras_datadesc_ref_pop_arr:
- *
+/** \brief Declare a new type being an array which size can be found with \ref gras_cbps_i_pop 
+ * 
  * Most of the time, you want to include a reference in your structure which
  * is a pointer to a dynamic array whose size is fixed by another field of 
  * your structure.
@@ -613,10 +559,66 @@ gras_datadesc_type_t
   sprintf(name,"%s[]*",element_type->name);
   res = gras_datadesc_ref(name,res);
 
-  xbt_free(name);
+  free(name);
 
   return res;
 }
+
+#include "xbt/dynar_private.h"
+static void gras_datadesc_dynar_cb(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data) {
+  gras_datadesc_type_t subtype;
+  xbt_dynar_t dynar=(xbt_dynar_t)data;
+   
+  memcpy(&dynar->free_f, &typedesc->extra, sizeof(dynar->free_f));
+
+  /* search for the elemsize in what we have. If elements are "int", typedesc got is "int[]*" */
+  subtype = gras_dd_find_field(typedesc,"data")->type;
+  
+  /* this is now a ref to array of what we're looking for */
+  subtype = subtype->category.ref_data.type;
+  subtype = subtype->category.array_data.type;
+   
+  DEBUG1("subtype is %s",subtype->name);
+
+  dynar->elmsize = subtype->size[GRAS_THISARCH];
+  dynar->size = dynar->used;
+}
+
+gras_datadesc_type_t
+gras_datadesc_dynar(gras_datadesc_type_t elm_t,
+		    void_f_pvoid_t *free_func) {
+   
+  char *buffname;
+  gras_datadesc_type_t res;
+  
+  buffname=xbt_new0(char, strlen(elm_t->name)+10);
+  sprintf(buffname,"dynar(%s)_s",elm_t->name);
+   
+  res = gras_datadesc_struct(buffname);
+  
+  gras_datadesc_struct_append(res, "size",    gras_datadesc_by_name("unsigned long int"));
+   
+  gras_datadesc_struct_append(res, "used",    gras_datadesc_by_name("unsigned long int"));
+  gras_datadesc_cb_field_push(res, "used");
+   
+  gras_datadesc_struct_append(res, "elmsize", gras_datadesc_by_name("unsigned long int"));
+   
+  gras_datadesc_struct_append(res, "data",    gras_datadesc_ref_pop_arr (elm_t));
+
+  gras_datadesc_struct_append(res, "free_f",  gras_datadesc_by_name("function pointer"));
+  memcpy(res->extra,&free_func,sizeof(free_func));
+      
+  gras_datadesc_struct_close(res);
+   
+  gras_datadesc_cb_recv(res,  &gras_datadesc_dynar_cb);
+
+  /* build a ref to it */
+  sprintf(buffname,"dynar(%s)",elm_t->name);
+  res=gras_datadesc_ref(buffname,res);
+  free(buffname);
+  return res;
+}
+
 xbt_error_t
 gras_datadesc_import_nws(const char           *name,
 			 const DataDescriptor *desc,
@@ -626,9 +628,6 @@ gras_datadesc_import_nws(const char           *name,
 }
 
 /**
- * gras_datadesc_cb_send:
- *
- * Add a pre-send callback to this datadesc.
  * (useful to push the sizes of the upcoming arrays, for example)
  */
 void gras_datadesc_cb_send (gras_datadesc_type_t          type,
@@ -636,21 +635,18 @@ void gras_datadesc_cb_send (gras_datadesc_type_t          type,
   type->send = send;
 }
 /**
- * gras_datadesc_cb_recv:
- *
- * Add a post-receive callback to this datadesc.
  * (useful to put the function pointers to the rigth value, for example)
  */
 void gras_datadesc_cb_recv(gras_datadesc_type_t          type,
 			   gras_datadesc_type_cb_void_t  recv) {
   type->recv = recv;
 }
-/**
+/*
  * gras_dd_find_field:
  * 
  * Returns the type descriptor of the given field. Abort on error.
  */
-static gras_datadesc_type_t 
+static gras_dd_cat_field_t
   gras_dd_find_field(gras_datadesc_type_t  type,
 		     const char           *field_name) {
    xbt_dynar_t         field_array;
@@ -668,7 +664,7 @@ static gras_datadesc_type_t
    }
    xbt_dynar_foreach(field_array,field_num,field) {
       if (!strcmp(field_name,field->name)) {
-	 return field->type;
+	 return field;
       }
    }
    ERROR2("No field nammed %s in %s",field_name,type->name);
@@ -677,37 +673,38 @@ static gras_datadesc_type_t
 }
 				  
 /**
- * gras_datadesc_cb_field_send:
- *
- * Add a pre-send callback to the given field of the datadesc (which must be a struct or union).
+ * The given datadesc must be a struct or union (abort if not).
  * (useful to push the sizes of the upcoming arrays, for example)
  */
 void gras_datadesc_cb_field_send (gras_datadesc_type_t          type,
 				  const char                   *field_name,
 				  gras_datadesc_type_cb_void_t  send) {
    
-   gras_datadesc_type_t sub_type=gras_dd_find_field(type,field_name);   
-   sub_type->send = send;
+   gras_dd_cat_field_t field=gras_dd_find_field(type,field_name);   
+   field->send = send;
 }
 
 /**
- * gras_datadesc_cb_field_push:
- *
- * Add a pre-send callback to the given field resulting in its value to be pushed to
- * the stack of sizes. It must be a int, unsigned int, long int or unsigned long int.
+ * The value, which must be an int, unsigned int, long int or unsigned long int
+ * is pushed to the stacks of sizes and can then be retrieved with 
+ * \ref gras_datadesc_ref_pop_arr or directly with \ref gras_cbps_i_pop.
  */
 void gras_datadesc_cb_field_push (gras_datadesc_type_t  type,
 				  const char           *field_name) {
    
-   gras_datadesc_type_t sub_type=gras_dd_find_field(type,field_name);
+   gras_dd_cat_field_t  field=gras_dd_find_field(type,field_name);
+   gras_datadesc_type_t sub_type=field->type;
+   
+   DEBUG3("add a PUSHy cb to '%s' field (type '%s') of '%s'",
+	  field_name,sub_type->name,type->name);
    if (!strcmp("int",sub_type->name)) {
-      sub_type->send = gras_datadesc_cb_push_int;
+      field->send = gras_datadesc_cb_push_int;
    } else if (!strcmp("unsigned int",sub_type->name)) {
-      sub_type->send = gras_datadesc_cb_push_uint;
+      field->send = gras_datadesc_cb_push_uint;
    } else if (!strcmp("long int",sub_type->name)) {
-      sub_type->send = gras_datadesc_cb_push_lint;
+      field->send = gras_datadesc_cb_push_lint;
    } else if (!strcmp("unsigned long int",sub_type->name)) {
-      sub_type->send = gras_datadesc_cb_push_ulint;
+      field->send = gras_datadesc_cb_push_ulint;
    } else {
       ERROR1("Field %s is not an int, unsigned int, long int neither unsigned long int",
 	     sub_type->name);
@@ -715,22 +712,18 @@ void gras_datadesc_cb_field_push (gras_datadesc_type_t  type,
    }
 }
 /**
- * gras_datadesc_cb_field_recv:
- *
- * Add a post-receive callback to the given field of the datadesc (which must be a struct or union).
+ * The given datadesc must be a struct or union (abort if not).
  * (useful to put the function pointers to the right value, for example)
  */
 void gras_datadesc_cb_field_recv(gras_datadesc_type_t          type,
 				 const char                   *field_name,
 				 gras_datadesc_type_cb_void_t  recv) {
    
-   gras_datadesc_type_t sub_type=gras_dd_find_field(type,field_name);   
-   sub_type->recv = recv;
+   gras_dd_cat_field_t field=gras_dd_find_field(type,field_name);   
+   field->recv = recv;
 }
 
-/**
- * gras_datadesc_free:
- *
+/*
  * Free a datadesc. Should only be called at xbt_exit. 
  */
 void gras_datadesc_free(gras_datadesc_type_t *type) {
@@ -744,13 +737,6 @@ void gras_datadesc_free(gras_datadesc_type_t *type) {
     /* nothing to free in there */
     break;
     
-  case e_gras_datadesc_type_cat_ignored:
-    if ((*type)->category.ignored_data.free_func) {
-      (*type)->category.ignored_data.free_func
-	((*type)->category.ignored_data.default_value);
-    }
-    break;
-    
   case e_gras_datadesc_type_cat_struct:
     xbt_dynar_free(&( (*type)->category.struct_data.fields ));
     break;
@@ -763,7 +749,162 @@ void gras_datadesc_free(gras_datadesc_type_t *type) {
     /* datadesc was invalid. Killing it is like euthanasy, I guess */
     break;
   }
-  xbt_free((*type)->name);
-  xbt_free(*type);
+  free((*type)->name);
+  free(*type);
   type=NULL;
 }
+
+/**
+ * gras_datadesc_type_cmp:
+ *
+ * Compares two datadesc types with the same semantic than strcmp.
+ *
+ * This comparison does not take the set headers into account (name and ID), 
+ * but only the payload (actual type description).
+ */
+int gras_datadesc_type_cmp(const gras_datadesc_type_t d1,
+			   const gras_datadesc_type_t d2) {
+  int ret,cpt;
+  gras_dd_cat_field_t field1,field2;
+  gras_datadesc_type_t field_desc_1,field_desc_2;
+
+  if (d1 == d2) return 0; /* easy optimization */
+
+  if (!d1 && d2) {
+    DEBUG0("ddt_cmp: !d1 && d2 => 1");
+    return 1;
+  }
+  if (!d1 && !d2) {
+    DEBUG0("ddt_cmp: !d1 && !d2 => 0");
+    return 0;
+  }
+  if ( d1 && !d2) {
+    DEBUG0("ddt_cmp: d1 && !d2 => -1");
+    return -1;
+  }
+
+  for (cpt=0; cpt<gras_arch_count; cpt++) {
+    if (d1->size[cpt] != d2->size[cpt]) {
+      DEBUG5("ddt_cmp: %s->size=%ld  !=  %s->size=%ld (on %s)",
+	     d1->name,d1->size[cpt],d2->name,d2->size[cpt],
+	     gras_arches[cpt].name);
+      return d1->size[cpt] >  d2->size[cpt] ? 1 : -1;
+    }
+
+    if (d1->alignment[cpt] != d2->alignment[cpt]) {
+      DEBUG5("ddt_cmp: %s->alignment=%ld  !=  %s->alignment=%ld (on %s)",
+	     d1->name,d1->alignment[cpt],d2->name,d2->alignment[cpt],
+	     gras_arches[cpt].name);
+      return d1->alignment[cpt] > d2->alignment[cpt] ? 1 : -1;
+    }
+
+    if (d1->aligned_size[cpt] != d2->aligned_size[cpt]) {
+      DEBUG5("ddt_cmp: %s->aligned_size=%ld  !=  %s->aligned_size=%ld (on %s)",
+	     d1->name,d1->aligned_size[cpt],d2->name,d2->aligned_size[cpt],
+	     gras_arches[cpt].name);
+      return d1->aligned_size[cpt] > d2->aligned_size[cpt] ? 1 : -1;
+    }
+  }
+
+  if (d1->category_code != d2->category_code) {
+    DEBUG4("ddt_cmp: %s->cat=%s  !=  %s->cat=%s",
+	   d1->name,gras_datadesc_cat_names[d1->category_code],
+	   d2->name,gras_datadesc_cat_names[d2->category_code]);
+    return d1->category_code > d2->category_code ? 1 : -1;
+  }
+
+  if (d1->send != d2->send) {
+    DEBUG4("ddt_cmp: %s->send=%p  !=  %s->send=%p",
+	   d1->name,(void*)d1->send, d2->name,(void*)d2->send);
+    return 1; /* ISO C forbids ordered comparisons of pointers to functions */
+  }
+
+  if (d1->recv != d2->recv) {
+    DEBUG4("ddt_cmp: %s->recv=%p  !=  %s->recv=%p",
+	   d1->name,(void*)d1->recv, d2->name,(void*)d2->recv);
+    return 1; /* ISO C forbids ordered comparisons of pointers to functions */
+  }
+
+  switch (d1->category_code) {
+  case e_gras_datadesc_type_cat_scalar:
+    if (d1->category.scalar_data.encoding != d2->category.scalar_data.encoding)
+      return d1->category.scalar_data.encoding > d2->category.scalar_data.encoding ? 1 : -1 ;
+    break;
+    
+  case e_gras_datadesc_type_cat_struct:    
+    if (xbt_dynar_length(d1->category.struct_data.fields) != 
+	xbt_dynar_length(d2->category.struct_data.fields)) {
+      DEBUG4("ddt_cmp: %s (having %lu fields) !=  %s (having %lu fields)",
+	     d1->name, xbt_dynar_length(d1->category.struct_data.fields),
+	     d2->name, xbt_dynar_length(d2->category.struct_data.fields));
+      
+      return xbt_dynar_length(d1->category.struct_data.fields) >
+	xbt_dynar_length(d2->category.struct_data.fields) ?
+	1 : -1;
+    }
+    xbt_dynar_foreach(d1->category.struct_data.fields, cpt, field1) {
+      
+      field2 = xbt_dynar_get_as(d2->category.struct_data.fields, cpt, gras_dd_cat_field_t);
+      field_desc_1 = field1->type;
+      field_desc_2 = field2->type;
+      ret = gras_datadesc_type_cmp(field_desc_1,field_desc_2);
+      if (ret) {
+	DEBUG6("%s->field[%d]=%s != %s->field[%d]=%s",
+	       d1->name,cpt,field1->name, 	       
+	       d2->name,cpt,field2->name);
+	return ret;
+      }
+      
+    }
+    break;
+    
+  case e_gras_datadesc_type_cat_union:
+    if (d1->category.union_data.selector != d2->category.union_data.selector) 
+      return 1;  /* ISO C forbids ordered comparisons of pointers to functions */
+    
+    if (xbt_dynar_length(d1->category.union_data.fields) != 
+	xbt_dynar_length(d2->category.union_data.fields))
+      return xbt_dynar_length(d1->category.union_data.fields) >
+	     xbt_dynar_length(d2->category.union_data.fields) ?
+	1 : -1;
+    
+    xbt_dynar_foreach(d1->category.union_data.fields, cpt, field1) {
+      
+      field2 = xbt_dynar_get_as(d2->category.union_data.fields, cpt, gras_dd_cat_field_t);
+      field_desc_1 = field1->type;
+      field_desc_2 = field2->type;
+      ret = gras_datadesc_type_cmp(field_desc_1,field_desc_2);
+      if (ret)
+	return ret;
+      
+    }
+    break;
+    
+    
+  case e_gras_datadesc_type_cat_ref:
+    if (d1->category.ref_data.selector != d2->category.ref_data.selector) 
+      return 1; /* ISO C forbids ordered comparisons of pointers to functions */
+    
+    if (d1->category.ref_data.type != d2->category.ref_data.type) 
+      return d1->category.ref_data.type > d2->category.ref_data.type ? 1 : -1;
+    break;
+    
+  case e_gras_datadesc_type_cat_array:
+    if (d1->category.array_data.type != d2->category.array_data.type) 
+      return d1->category.array_data.type > d2->category.array_data.type ? 1 : -1;
+    
+    if (d1->category.array_data.fixed_size != d2->category.array_data.fixed_size) 
+      return d1->category.array_data.fixed_size > d2->category.array_data.fixed_size ? 1 : -1;
+    
+    if (d1->category.array_data.dynamic_size != d2->category.array_data.dynamic_size) 
+      return 1; /* ISO C forbids ordered comparisons of pointers to functions */
+    
+    break;
+    
+  default:
+    /* two stupidly created ddt are equally stupid ;) */
+    break;
+  }
+  return 0;
+  
+}