3 /* gras/datadesc.h - Describing the data you want to exchange */
5 /* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved. */
7 /* This program is free software; you can redistribute it and/or modify it
8 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #ifndef GRAS_DATADESC_H
11 #define GRAS_DATADESC_H
13 #include "xbt/misc.h" /* SG_BEGIN_DECL */
14 #include "xbt/dynar.h" /* void_f_pvoid_t */
18 /** @addtogroup GRAS_dd Data description
19 * @brief Describing data to be exchanged
21 * Since GRAS takes care of potential representation conversion when the platform is heterogeneous,
22 * any data which transits on the network must be described beforehand.
24 * There is several possible interfaces for this, ranging from the really completely automatic parsing to
25 * completely manual. Let's study each of them from the simplest to the more advanced:
27 * - Section \ref GRAS_dd_basic presents how to retrieve and use an already described type.
28 * - Section \ref GRAS_dd_auto shows how to get GRAS parsing your type description automagically. This
29 * is unfortunately not always possible (only works for some structures), but if it is for your data,
30 * this is definitly the way to go.
31 * - Section \ref GRAS_dd_manual presents how to build a description manually. This is useful when you want
32 * to describe an array or a pointer of pre-defined structures.
33 * - You sometimes need to exchange informations between descriptions at send or receive time. This is
34 * for example useful when your structure contains an array which size is given by another field of the
36 * - Section \ref GRAS_dd_cb_simple provides a simple interface to do so, allowing to share integers stored on a stack.
37 * - Section \ref GRAS_dd_cb_full provides a full featured interface to do so, but it may reveal somehow difficult to use.
39 /** @defgroup GRAS_dd_basic Basic operations on data descriptions
41 * \htmlonly <!-- DOXYGEN_NAVBAR_LABEL="Basics" --> \endhtmlonly
43 * If you only want to send pre-existing types, simply retrieve the pre-defined description with
44 * the \ref gras_datadesc_by_name function. Existing types entail:
45 * - char (both signed and unsigned)
46 * - int (short, regular, long and long long, both signed and unsigned)
48 * - string (which is indeed a reference to a dynamically sized array of char, strlen being used to retrieve the size)
50 * Example:\verbatim gras_datadesc_type_t i = gras_datadesc_by_name("int");
51 gras_datadesc_type_t uc = gras_datadesc_by_name("unsigned char");
52 gras_datadesc_type_t str = gras_datadesc_by_name("string");\endverbatim
56 /** @brief Opaque type describing a type description. */
57 typedef struct s_gras_datadesc_type *gras_datadesc_type_t;
59 /** \brief Search a type description from its name */
60 XBT_PUBLIC(gras_datadesc_type_t) gras_datadesc_by_name(const char *name);
61 XBT_PUBLIC(gras_datadesc_type_t) gras_datadesc_by_name_or_null(const char
66 /** @defgroup GRAS_dd_auto Automatic parsing of data descriptions
68 * \htmlonly <!-- DOXYGEN_NAVBAR_LABEL="Automatic parsing" --> \endhtmlonly
70 * If you need to declare a new datatype, this is the simplest way to describe it to GRAS. Simply
71 * enclose its type definition into a \ref GRAS_DEFINE_TYPE macro call, and you're set. Here is
72 * an type declaration example: \verbatim GRAS_DEFINE_TYPE(mytype,struct mytype {
76 * The type is then both copied verbatim into your source file and stored for further parsing. This allows
77 * you to let GRAS parse the exact version you are actually using in your program.
78 * You can then retrieve the corresponding type description with \ref gras_datadesc_by_symbol.
79 * Don't worry too much for the performances, the type is only parsed once and a binary representation
80 * is stored and used in any subsequent calls.
82 * If your structure contains any pointer, you have to explain GRAS the size of the pointed array. This
83 * can be 1 in the case of simple references, or more in the case of regular arrays. For that, use the
84 * \ref GRAS_ANNOTE macro within the type declaration you are passing to \ref GRAS_DEFINE_TYPE. This macro
85 * rewrites itself to nothing in the declaration (so they won't pollute the type definition copied verbatim
86 * into your code), and give some information to GRAS about your pointer.
88 * GRAS_ANNOTE takes two arguments being the key name and the key value. For now, the only accepted key name
89 * is "size", to specify the length of the pointed array. It can either be:
90 * - the string "1" (without the quote),
91 * - the name of another field of the structure
92 * - a sort of computed expression for multidimensional arrays (see below -- pay attention to the warnings below).
94 * Here is an example:\verbatim GRAS_DEFINE_TYPE(s_clause,
97 struct s_array *father GRAS_ANNOTE(size,1);
99 int *data GRAS_ANNOTE(size,length);
102 int *matrix GRAS_ANNOTE(size,rows*cols);
105 * It specifies that the structure s_array contains six fields, that the \a name field is a classical null-terminated
106 * char* string (#xbt_string_t is just an helper type defined exactly to help the parsing macro to specify the semantic of the pointer),
107 * that \a father field is a simple reference, that the size of the array pointed by \a data is the \a length field, and that the
108 * \a matrix field is an arraywhich size is the result of \a rows times \a cols.
110 * \warning Since GRAS_DEFINE_TYPE is a macro, you shouldn't put any comma in your type definition
111 * (comma separates macro args). For example, change \verbatim int a, b;\endverbatim to \verbatim int a;
114 * \section gras_dd_define \#define and fixed size array
116 * If you want to exchange arrays which size is given at compilation time by a
117 * \#defined constant, you need to keep GRAS informed. It would be done the
120 \verbatim #define BLOCK_SIZE 32
121 GRAS_DEFINE_TYPE(s_toto,
123 double data[BLOCK_SIZE];
126 void register_messages() {
127 gras_datadesc_type_t toto_type;
129 gras_datadesc_set_const("BLOCK_SIZE",BLOCK_SIZE);
130 toto_type = gras_datadesc_by_symbol(s_toto);
133 * The form <tt>gras_datadesc_set_const("BLOCK_SIZE",BLOCK_SIZE);</tt> ensures
134 * that when you change the definition of the constant, GRAS keeps informed of
135 * the right value. Passing the numerical value of the constant as second
136 * argument would be a bad idea to that regard. Of course, the call to
137 * gras_datadesc_set_const() should come before any gras_datadesc_by_symbol()
138 * containing references to it.
140 * \section GRAS_dd_multidim Defining multidimentional arrays
142 * The mecanism for multidimensional arrays is known to be fragile and cumbersome. If you want to use it,
143 * you have to understand how it is implemented: the multiplication is performed using the sizes stack. In previous example,
144 * a \ref gras_datadesc_cb_push_int callback is added to the \a rows field and a \ref gras_datadesc_cb_push_int_mult one is
145 * added to \a cols. So, when the structure is sent, the \a rows field push its value onto the stack, then the \a cols field
146 * retrieve this value from the stack, compute (and push) the multiplication value. The \a matrix field can then retrieve this
147 * value by poping the array. There is several ways for this to go wrong:
148 * - if the matrix field is placed before the sizes, the right value won't get pushed into the stack soon enough.
149 * Reorder your structure fields if needed.
150 * - if you write GRAS_ANNOTE(size,cols*rows); in previous example (inverting rows and cols in annotation),
151 * \a rows will be given a \ref gras_datadesc_cb_push_int_mult. This cannot work since it will try to
152 * pop the value which will be pushed by \a cols <i>afterward</i>.
153 * - if you have more than one matrix in your structure, don't interleave the size. They are pushed/poped in the structure order.
154 * - if some of the sizes are used in more than one matrix, you cannot use this mecanism -- sorry.
156 * If you cannot express your datadescs with this mechanism, you'll have to use the more advanced
157 * (and somehow complex) one described in the \ref GRAS_dd_cb_full.
159 * \section GRAS_dd_multifile Projects spanning over multiple files
161 * GRAS_DEFINE_TYPE declares some symbols to work, it needs some special
162 * care when used in several files. In such case, you want the regular type
163 * definition in all files, but the gras specific symbol defined in only
164 * one file. For example, consider the following gras project sketch.
166 \verbatim #include <gras.h>
168 GRAS_DEFINE_TYPE(my_type,struct my_type {
174 int client(int argc, char *argv[]) {
178 int server(int argc, char *argv[]) {
182 * If you want to split this in two files (one for each kind of processes),
183 * you need to put the GRAS_DEFINE_TYPE block in a separate header (so that
184 * each process kind see the associated C type definition). But
185 * then you cannot include this right away in all files because the extra
186 * symbols containing the GRAS definition would be dupplicated.
188 * You thus have to decide in which C file the symbols will live. In that
189 * file, include the header without restriction:
191 \verbatim #include "my_header.h"
193 int client(int argc, char *argv[]) {
197 * And in the other files needing the C definitions without the extra GRAS
198 * symbols, declare the symbol GRAS_DEFINE_TYPE_EXTERN before loading gras.h:
200 \verbatim #define GRAS_DEFINE_TYPE_EXTERN
202 #include "my_header.h"
204 int server(int argc, char *argv[]) {
209 * Sometimes, the situation is even more complicated: There is some shared
210 * messages that you want to see from every file, and some private messages
211 * that you want to be defined only in one C file.
212 * In that case, use the previous trick for common messages, and use
213 * #GRAS_DEFINE_TYPE_LOCAL for the private messages.
215 * For now, there is no way to have semi-private symbols (for example shared
216 * in all files of a library), sorry. Use functions as interface to your
217 * library instead of publishing directly the messages.
223 /** @brief Automatically parse C code
226 #define GRAS_DEFINE_TYPE(name,def) \
227 const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
229 #ifndef DOXYGEN_SKIP /* doxygen don't like macro fun too much */
230 # ifdef GRAS_DEFINE_TYPE_EXTERN
231 # undef GRAS_DEFINE_TYPE
232 # define GRAS_DEFINE_TYPE(name,def) def
233 # undef GRAS_DEFINE_TYPE_EXTERN
237 /** @brief if this symbol is defined, the \a GRAS_DEFINE_TYPE symbols live in another file.
240 #define GRAS_DEFINE_TYPE_EXTERN 1
241 /* leave the fun of declaring this to the user */
242 #undef GRAS_DEFINE_TYPE_EXTERN
244 /** @brief Define a symbol to be automatically parsed, disregarding #GRAS_DEFINE_TYPE_EXTERN
247 * Call this macro instead of #GRAS_DEFINE_TYPE if you had to define #GRAS_DEFINE_TYPE_EXTERN
248 * to load some external symbols, but if you now want to automatically parse the content of
249 * your private messages.
251 #define GRAS_DEFINE_TYPE_LOCAL(name, def) \
252 const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
254 /** @brief Retrieve a datadesc which was previously parsed
257 #define gras_datadesc_by_symbol(name) \
258 (gras_datadesc_by_name_or_null(#name) ? \
259 gras_datadesc_by_name_or_null(#name) : \
260 gras_datadesc_parse(#name, \
261 _gras_this_type_symbol_does_not_exist__##name) \
265 * @brief Add an annotation to a type to be automatically parsed
267 #define GRAS_ANNOTE(key,val)
269 /** @brief Defines the value of a define to the datatype parsing infrastructure
271 XBT_PUBLIC(void) gras_datadesc_set_const(const char *name, int value);
275 XBT_PUBLIC(gras_datadesc_type_t)
276 gras_datadesc_parse(const char *name, const char *C_statement);
278 /** @defgroup GRAS_dd_manual Simple manual data description
281 * Here are the functions to use if you want to declare your description manually.
282 * The function names should be self-explanatory in most cases.
284 * You can add callbacks to the datatypes doing any kind of action you may want. Usually,
285 * pre-send callbacks are used to prepare the type expedition while post-receive callbacks
286 * are used to fix any issue after the receive.
288 * If your types are dynamic, you'll need to add some extra callback. For example, there is a
289 * specific callback for the string type which is in charge of computing the length of the char
290 * array. This is done with the cbps mechanism, explained in next section.
292 * If your types may contain pointer cycle, you must specify it to GRAS using the @ref gras_datadesc_cycle_set.
297 unsigned long int l1;
299 unsigned long int l2;
302 my_type=gras_datadesc_struct("mystruct");
303 gras_datadesc_struct_append(my_type,"c1", gras_datadesc_by_name("unsigned char"));
304 gras_datadesc_struct_append(my_type,"l1", gras_datadesc_by_name("unsigned long"));
305 gras_datadesc_struct_append(my_type,"c2", gras_datadesc_by_name("unsigned char"));
306 gras_datadesc_struct_append(my_type,"l2", gras_datadesc_by_name("unsigned long int"));
307 gras_datadesc_struct_close(my_type);
309 my_type=gras_datadesc_ref("mystruct*", gras_datadesc_by_name("mystruct"));
311 [Use my_type to send pointers to mystruct data]\endverbatim
316 /** \brief Opaque type describing a type description callback persistant state. */
317 typedef struct s_gras_cbps *gras_cbps_t;
319 /* callbacks prototypes */
320 /** \brief Prototype of type callbacks returning nothing. */
321 typedef void (*gras_datadesc_type_cb_void_t) (gras_datadesc_type_t
322 typedesc, gras_cbps_t vars,
324 /** \brief Prototype of type callbacks returning an int. */
325 typedef int (*gras_datadesc_type_cb_int_t) (gras_datadesc_type_t
326 typedesc, gras_cbps_t vars,
328 /** \brief Prototype of type callbacks selecting a type. */
330 gras_datadesc_type_t(*gras_datadesc_selector_t) (gras_datadesc_type_t
336 /******************************************
337 **** Declare datadescription yourself ****
338 ******************************************/
340 XBT_PUBLIC(gras_datadesc_type_t) gras_datadesc_struct(const char *name);
341 XBT_PUBLIC(void) gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
343 gras_datadesc_type_t field_type);
344 XBT_PUBLIC(void) gras_datadesc_struct_close(gras_datadesc_type_t struct_type);
347 XBT_PUBLIC(gras_datadesc_type_t) gras_datadesc_union(const char *name,
348 gras_datadesc_type_cb_int_t
350 XBT_PUBLIC(void) gras_datadesc_union_append(gras_datadesc_type_t union_type,
352 gras_datadesc_type_t field_type);
353 XBT_PUBLIC(void) gras_datadesc_union_close(gras_datadesc_type_t union_type);
356 XBT_PUBLIC(gras_datadesc_type_t)
357 gras_datadesc_ref(const char *name, gras_datadesc_type_t referenced_type);
358 XBT_PUBLIC(gras_datadesc_type_t)
359 gras_datadesc_copy(const char *name, gras_datadesc_type_t copied_type);
360 XBT_PUBLIC(gras_datadesc_type_t)
361 gras_datadesc_ref_generic(const char *name,
362 gras_datadesc_selector_t selector);
364 XBT_PUBLIC(gras_datadesc_type_t)
365 gras_datadesc_array_fixed(const char *name,
366 gras_datadesc_type_t element_type,
367 long int fixed_size);
368 XBT_PUBLIC(gras_datadesc_type_t)
369 gras_datadesc_array_dyn(const char *name,
370 gras_datadesc_type_t element_type,
371 gras_datadesc_type_cb_int_t dynamic_size);
372 XBT_PUBLIC(gras_datadesc_type_t)
373 gras_datadesc_ref_pop_arr(gras_datadesc_type_t element_type);
375 XBT_PUBLIC(gras_datadesc_type_t)
376 gras_datadesc_dynar(gras_datadesc_type_t elm_t, void_f_pvoid_t free_func);
377 XBT_PUBLIC(gras_datadesc_type_t)
378 gras_datadesc_matrix(gras_datadesc_type_t elm_t, void_f_pvoid_t const free_f);
380 /*********************************
381 * Change stuff within datadescs *
382 *********************************/
384 /** \brief Specify that this type may contain cycles */
385 XBT_PUBLIC(void) gras_datadesc_cycle_set(gras_datadesc_type_t type);
386 /** \brief Specify that this type do not contain any cycles (default) */
387 XBT_PUBLIC(void) gras_datadesc_cycle_unset(gras_datadesc_type_t type);
388 /** \brief Add a pre-send callback to this datadesc. */
389 XBT_PUBLIC(void) gras_datadesc_cb_send(gras_datadesc_type_t type,
390 gras_datadesc_type_cb_void_t pre);
391 /** \brief Add a post-receive callback to this datadesc.*/
392 XBT_PUBLIC(void) gras_datadesc_cb_recv(gras_datadesc_type_t type,
393 gras_datadesc_type_cb_void_t post);
394 /** \brief Add a pre-send callback to the given field of the datadesc */
395 XBT_PUBLIC(void) gras_datadesc_cb_field_send(gras_datadesc_type_t type,
396 const char *field_name,
397 gras_datadesc_type_cb_void_t
399 /** \brief Add a post-receive callback to the given field of the datadesc */
400 XBT_PUBLIC(void) gras_datadesc_cb_field_recv(gras_datadesc_type_t type,
401 const char *field_name,
402 gras_datadesc_type_cb_void_t
404 /** \brief Add a pre-send callback to the given field resulting in its value to be pushed */
405 XBT_PUBLIC(void) gras_datadesc_cb_field_push(gras_datadesc_type_t type,
406 const char *field_name);
407 /** \brief Add a pre-send callback to the given field resulting in its value multiplied to any previously pushed value and then pushed back */
408 XBT_PUBLIC(void) gras_datadesc_cb_field_push_multiplier(gras_datadesc_type_t
412 /******************************
413 * Get stuff within datadescs *
414 ******************************/
415 /** \brief Returns the name of a datadescription */
416 XBT_PUBLIC(const char *) gras_datadesc_get_name(gras_datadesc_type_t ddt);
417 /** \brief Returns the identifier of a datadescription */
418 XBT_PUBLIC(int) gras_datadesc_get_id(gras_datadesc_type_t ddt);
422 /** @defgroup GRAS_dd_cb_simple Data description with Callback Persistant State: Simple push/pop mechanism
425 * Sometimes, one of the callbacks need to leave information for the next ones. If this is a simple integer (such as
426 * an array size), you can use the functions described here. If not, you'll have to play with the complete cbps interface.
428 * \htmlonly <!-- DOXYGEN_NAVBAR_LABEL="Simple push/pop Callback State" -->\endhtmlonly
430 * Here is an example:\verbatim
436 my_type=gras_datadesc_struct("s_array");
437 gras_datadesc_struct_append(my_type,"length", gras_datadesc_by_name("int"));
438 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
440 gras_datadesc_struct_append(my_type,"data",
441 gras_datadesc_array_dyn ("s_array::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
442 gras_datadesc_struct_close(my_type);
446 * The *_mult versions are intended for multi-dimensional arrays: They multiply their value to the previously pushed one
447 * (by another field callback) and push the result of the multiplication back. An example of use follows. Please note
448 * that the first field needs a regular push callback, not a multiplier one. Think of it as a stacked calculator (man dc(1)).\verbatim
455 my_type=gras_datadesc_struct("s_matrix");
456 gras_datadesc_struct_append(my_type,"row", gras_datadesc_by_name("int"));
457 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
458 gras_datadesc_struct_append(my_type,"col", gras_datadesc_by_name("int"));
459 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int_mult);
461 gras_datadesc_struct_append(my_type,"data",
462 gras_datadesc_array_dyn ("s_matrix::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
463 gras_datadesc_struct_close(my_type);
469 XBT_PUBLIC(void) gras_cbps_i_push(gras_cbps_t ps, int val);
470 XBT_PUBLIC(int) gras_cbps_i_pop(gras_cbps_t ps);
472 XBT_PUBLIC(int) gras_datadesc_cb_pop(gras_datadesc_type_t typedesc,
473 gras_cbps_t vars, void *data);
475 XBT_PUBLIC(void) gras_datadesc_cb_push_int(gras_datadesc_type_t typedesc,
476 gras_cbps_t vars, void *data);
477 XBT_PUBLIC(void) gras_datadesc_cb_push_uint(gras_datadesc_type_t typedesc,
478 gras_cbps_t vars, void *data);
479 XBT_PUBLIC(void) gras_datadesc_cb_push_lint(gras_datadesc_type_t typedesc,
480 gras_cbps_t vars, void *data);
481 XBT_PUBLIC(void) gras_datadesc_cb_push_ulint(gras_datadesc_type_t typedesc,
482 gras_cbps_t vars, void *data);
484 XBT_PUBLIC(void) gras_datadesc_cb_push_int_mult(gras_datadesc_type_t typedesc,
485 gras_cbps_t vars, void *data);
486 XBT_PUBLIC(void) gras_datadesc_cb_push_uint_mult(gras_datadesc_type_t
487 typedesc, gras_cbps_t vars,
489 XBT_PUBLIC(void) gras_datadesc_cb_push_lint_mult(gras_datadesc_type_t
490 typedesc, gras_cbps_t vars,
492 XBT_PUBLIC(void) gras_datadesc_cb_push_ulint_mult(gras_datadesc_type_t
493 typedesc, gras_cbps_t vars,
499 /** @defgroup GRAS_dd_cb_full Data description with Callback Persistant State: Full featured interface
502 * Sometimes, one of the callbacks need to leave information for the next
503 * ones. If the simple push/pop mechanism introduced in previous section
504 * isn't enough, you can always use this full featured one. The bad point is
505 * that it is quite badly documented...
507 * \htmlonly <!-- DOXYGEN_NAVBAR_LABEL="Full featured Callback State" -->\endhtmlonly
513 XBT_PUBLIC(void) gras_cbps_v_pop(gras_cbps_t ps, const char *name,
514 /* OUT */ gras_datadesc_type_t * ddt,
515 /* OUT */ void **res);
516 XBT_PUBLIC(void) gras_cbps_v_push(gras_cbps_t ps,
518 void *data, gras_datadesc_type_t ddt);
519 XBT_PUBLIC(void) gras_cbps_v_set(gras_cbps_t ps,
521 void *data, gras_datadesc_type_t ddt);
523 XBT_PUBLIC(void *) gras_cbps_v_get(gras_cbps_t ps, const char *name,
524 /* OUT */ gras_datadesc_type_t * ddt);
526 XBT_PUBLIC(void) gras_cbps_block_begin(gras_cbps_t ps);
527 XBT_PUBLIC(void) gras_cbps_block_end(gras_cbps_t ps);
533 /*******************************
534 **** About data convertion ****
535 *******************************/
536 XBT_PUBLIC(int) gras_arch_selfid(void); /* ID of this arch */
539 /*****************************
540 **** NWS datadescription * FIXME: obsolete?
541 *****************************/
544 * Basic types we can embeed in DataDescriptors.
547 { CHAR_TYPE, DOUBLE_TYPE, FLOAT_TYPE, INT_TYPE, LONG_TYPE, SHORT_TYPE,
548 UNSIGNED_INT_TYPE, UNSIGNED_LONG_TYPE, UNSIGNED_SHORT_TYPE, STRUCT_TYPE
550 #define SIMPLE_TYPE_COUNT 9
552 /** \brief Describe a collection of data.
554 ** A description of a collection of \a type data. \a repetitions is used only
555 ** for arrays; it contains the number of elements. \a offset is used only for
556 ** struct members in host format; it contains the offset of the member from the
557 ** beginning of the struct, taking into account internal padding added by the
558 ** compiler for alignment purposes. \a members, \a length, and \a tailPadding are
559 ** used only for STRUCT_TYPE data; the \a length -long array \a members describes
560 ** the members of the nested struct, and \a tailPadding indicates how many
561 ** padding bytes the compiler adds to the end of the structure.
564 typedef struct DataDescriptorStruct {
568 /*@null@ */ struct DataDescriptorStruct *members;
572 /** DataDescriptor for an array */
573 #define SIMPLE_DATA(type,repetitions) \
574 {type, repetitions, 0, NULL, 0, 0}
575 /** DataDescriptor for an structure member */
576 #define SIMPLE_MEMBER(type,repetitions,offset) \
577 {type, repetitions, offset, NULL, 0, 0}
578 /** DataDescriptor for padding bytes */
579 #define PAD_BYTES(structType,lastMember,memberType,repetitions) \
580 sizeof(structType) - offsetof(structType, lastMember) - \
581 sizeof(memberType) * repetitions
583 XBT_PUBLIC(gras_datadesc_type_t)
584 gras_datadesc_import_nws(const char *name,
585 const DataDescriptor * desc, unsigned long howmany);
589 #endif /* GRAS_DATADESC_H */