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 (Communication facility)
23 * Since GRAS takes care of potential representation conversion when the platform is heterogeneous,
24 * any data which transits on the network must be described beforehand.
26 * There is several possible interfaces for this, ranging from the really completely automatic parsing to
27 * completely manual. Let's study each of them from the simplest to the more advanced.
29 * \warning At least, I would like to present those sections in the right order, but doxygen prevents me
30 * from doing so. There is a weird bug I fail to circumvent here. The right order is naturally:
32 * -# Automatic parsing
33 * -# Simple manual definitions
34 * -# Callback Persistant State: Simple push/pop mechanism
35 * -# Callback Persistant State: Full featured mechanism
39 /** @name 1. basic operations
41 * If you only want to send pre-existing types, simply retrieve the pre-defined description with
42 * the \ref gras_datadesc_by_name function. Existing types entail:
43 * - char (both signed and unsigned)
44 * - int (short, regular, long and long long, both signed and unsigned)
46 * - string (which is indeed a reference to a dynamically sized array of char, strlen being used to retrive the size)
48 * Example:\verbatim gras_datadesc_type_t i = gras_datadesc_by_name("int");
49 gras_datadesc_type_t uc = gras_datadesc_by_name("unsigned char");
50 gras_datadesc_type_t str = gras_datadesc_by_name("string");\endverbatim
54 /** @brief Opaque type describing a type description. */
55 typedef struct s_gras_datadesc_type *gras_datadesc_type_t;
57 /** \brief Search a type description from its name */
58 gras_datadesc_type_t gras_datadesc_by_name(const char *name);
62 /** @name 2. Automatic parsing
64 * If you need to declare a new datatype, this is the simplest way to describe it to GRAS. Simply
65 * enclose its type definition into a \ref GRAS_DEFINE_TYPE macro call, and you're set. Here is
66 * an type declaration example: \verbatim GRAS_DEFINE_TYPE(mytype,struct mytype {
70 * The type is then both copied verbatim into your source file and stored for further parsing. This allows
71 * you to let GRAS parse the exact version you are actually using in your program.
72 * You can then retrieve the corresponding type description with \ref gras_datadesc_by_symbol.
73 * Don't worry too much for the performances, the type is only parsed once and a binary representation
74 * is stored and used in any subsequent calls.
76 * If your structure contains any pointer, you have to explain GRAS the size of the pointed array. This
77 * can be 1 in the case of simple references, or more in the case of regular arrays. For that, use the
78 * \ref GRAS_ANNOTE macro within the type declaration you are passing to \ref GRAS_DEFINE_TYPE. This macro
79 * rewrites itself to nothing in the declaration (so they won't pollute the type definition copied verbatim
80 * into your code), and give some information to GRAS about your pointer.
82 * GRAS_ANNOTE takes two arguments being the key name and the key value. For now, the only accepted key name
83 * is "size", to specify the length of the pointed array. It can either be:
84 * - the string "1" (without the quote),
85 * - the name of another field of the structure
86 * - a sort of computed expression for multidimensional arrays (see below -- pay attention to the warnings below).
88 * Here is an example:\verbatim GRAS_DEFINE_TYPE(s_clause,
90 struct s_array *father GRAS_ANNOTE(size,1);
92 int *data GRAS_ANNOTE(size,length);
95 int *matrix GRAS_ANNOTE(size,rows*cols);
98 * It specifies that the structure s_array contains five fields, that the \a father field is a simple reference,
99 * that the size of the array pointed by \a data is the \a length field, and that the \a matrix field is an array
100 * which size is the result of \a rows times \a cols.
102 * \warning The mecanism for multidimensional arrays is known to be fragile and cumbersome. If you want to use it,
103 * you have to understand how it is implemented: the multiplication is performed using the sizes stack. In previous example,
104 * 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
105 * added to \a cols. So, when the structure is sent, the rows field push its value onto the stack, then the \a cols field
106 * retrieve this value from the stack, compute (and push) the multiplication value. The \a matrix field can then retrive this
107 * value by poping the array. There is several ways for this to go wrong:
108 * - if the matrix field is placed before the sizes, the right value won't get pushed into the stack soon enough. Reorder your structure fields if needed.
109 * - if you write GRAS_ANNOTE(size,cols*rows); in previous example (inverting rows and cols in annotation),
110 * \a rows will be given a \ref gras_datadesc_cb_push_int_mult. This cannot work since it will try to
111 * pop the value which will be pushed by \a cols <i>afterward</i>.
112 * - if you have more than one matrix in your structure, don't interleave the size. They are pushed/poped in the structure order.
113 * - if some of the sizes are used in more than one matrix, you cannot use this mecanism -- sorry.
115 * If you cannot express your datadescs with this mechanism, you'll have to use the more advanced
116 * (and somehow complex) one described below.
118 * \warning Since GRAS_DEFINE_TYPE is a macro, you shouldn't put any comma in your type definition
119 * (comma separates macro args). For example, change \verbatim int a, b;\endverbatim to \verbatim int a;
125 /** @brief Automatically parse C code
128 #define GRAS_DEFINE_TYPE(name,def) \
129 static const char * _gras_this_type_symbol_does_not_exist__##name=#def; def
131 /** @brief Retrieve a datadesc which was previously parsed
134 #define gras_datadesc_by_symbol(name) \
135 (gras_datadesc_by_name(#name) ? \
136 gras_datadesc_by_name(#name) : \
137 gras_datadesc_parse(#name, \
138 _gras_this_type_symbol_does_not_exist__##name) \
142 * @brief Add an annotation to a type to be automatically parsed
144 #define GRAS_ANNOTE(key,val)
149 gras_datadesc_parse(const char *name, const char *C_statement);
151 /** @name 3. Simple manual definitions
153 * Here are the functions to use if you want to declare your description manually.
154 * The function names should be self-explanatory in most cases.
156 * You can add callbacks to the datatypes doing any kind of action you may want. Usually,
157 * pre-send callbacks are used to prepare the type expedition while post-receive callbacks
158 * are used to fix any issue after the receive.
160 * If your types are dynamic, you'll need to add some extra callback. For example, there is a
161 * specific callback for the string type which is in charge of computing the length of the char
162 * array. This is done with the cbps mechanism, explained in next section.
164 * If your types may contain pointer cycle, you must specify it to GRAS using the @ref gras_datadesc_cycle_set.
169 unsigned long int l1;
171 unsigned long int l2;
174 my_type=gras_datadesc_struct("mystruct");
175 gras_datadesc_struct_append(my_type,"c1", gras_datadesc_by_name("unsigned char"));
176 gras_datadesc_struct_append(my_type,"l1", gras_datadesc_by_name("unsigned long"));
177 gras_datadesc_struct_append(my_type,"c2", gras_datadesc_by_name("unsigned char"));
178 gras_datadesc_struct_append(my_type,"l2", gras_datadesc_by_name("unsigned long int"));
179 gras_datadesc_struct_close(my_type);
181 my_type=gras_datadesc_ref("mystruct*", gras_datadesc_by_name("mystruct"));
183 [Use my_type to send pointers to mystruct data]\endverbatim
188 /** \brief Opaque type describing a type description callback persistant state. */
189 typedef struct s_gras_cbps *gras_cbps_t;
191 /* callbacks prototypes */
192 /** \brief Prototype of type callbacks returning nothing. */
193 typedef void (*gras_datadesc_type_cb_void_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
194 /** \brief Prototype of type callbacks returning an int. */
195 typedef int (*gras_datadesc_type_cb_int_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
196 /** \brief Prototype of type callbacks selecting a type. */
197 typedef gras_datadesc_type_t (*gras_datadesc_selector_t)(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
200 /******************************************
201 **** Declare datadescription yourself ****
202 ******************************************/
204 gras_datadesc_type_t gras_datadesc_struct(const char *name);
205 void gras_datadesc_struct_append(gras_datadesc_type_t struct_type,
207 gras_datadesc_type_t field_type);
208 void gras_datadesc_struct_close(gras_datadesc_type_t struct_type);
211 gras_datadesc_type_t gras_datadesc_union(const char *name,
212 gras_datadesc_type_cb_int_t selector);
213 void gras_datadesc_union_append(gras_datadesc_type_t union_type,
215 gras_datadesc_type_t field_type);
216 void gras_datadesc_union_close(gras_datadesc_type_t union_type);
220 gras_datadesc_ref(const char *name,
221 gras_datadesc_type_t referenced_type);
223 gras_datadesc_ref_generic(const char *name,
224 gras_datadesc_selector_t selector);
227 gras_datadesc_array_fixed(const char *name,
228 gras_datadesc_type_t element_type,
229 long int fixed_size);
231 gras_datadesc_array_dyn(const char *name,
232 gras_datadesc_type_t element_type,
233 gras_datadesc_type_cb_int_t dynamic_size);
235 gras_datadesc_ref_pop_arr(gras_datadesc_type_t element_type);
238 gras_datadesc_dynar(gras_datadesc_type_t elm_t,
239 void_f_pvoid_t *free_func);
241 /*********************************
242 * Change stuff within datadescs *
243 *********************************/
245 /** \brief Specify that this type may contain cycles */
246 void gras_datadesc_cycle_set(gras_datadesc_type_t type);
247 /** \brief Specify that this type do not contain any cycles (default) */
248 void gras_datadesc_cycle_unset(gras_datadesc_type_t type);
249 /** \brief Add a pre-send callback to this datadesc. */
250 void gras_datadesc_cb_send (gras_datadesc_type_t type,
251 gras_datadesc_type_cb_void_t pre);
252 /** \brief Add a post-receive callback to this datadesc.*/
253 void gras_datadesc_cb_recv(gras_datadesc_type_t type,
254 gras_datadesc_type_cb_void_t post);
255 /** \brief Add a pre-send callback to the given field of the datadesc */
256 void gras_datadesc_cb_field_send (gras_datadesc_type_t type,
257 const char *field_name,
258 gras_datadesc_type_cb_void_t pre);
259 /** \brief Add a post-receive callback to the given field of the datadesc */
260 void gras_datadesc_cb_field_recv(gras_datadesc_type_t type,
261 const char *field_name,
262 gras_datadesc_type_cb_void_t post);
263 /** \brief Add a pre-send callback to the given field resulting in its value to be pushed */
264 void gras_datadesc_cb_field_push (gras_datadesc_type_t type,
265 const char *field_name);
266 /** \brief Add a pre-send callback to the given field resulting in its value multiplied to any previously pushed value and then pushed back */
267 void gras_datadesc_cb_field_push_multiplier (gras_datadesc_type_t type,
268 const char *field_name);
270 /******************************
271 * Get stuff within datadescs *
272 ******************************/
273 /** \brief Returns the name of a datadescription */
274 const char * gras_datadesc_get_name(gras_datadesc_type_t ddt);
275 /** \brief Returns the identifier of a datadescription */
276 int gras_datadesc_get_id(gras_datadesc_type_t ddt);
280 /** @name 4. Callback Persistant State: Simple push/pop mechanism
282 * Sometimes, one of the callbacks need to leave information for the next ones. If this is a simple integer (such as
283 * an array size), you can use the functions described here. If not, you'll have to play with the complete cbps interface.
286 * Here is an example:\verbatim
292 my_type=gras_datadesc_struct("s_array");
293 gras_datadesc_struct_append(my_type,"length", gras_datadesc_by_name("int"));
294 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
296 gras_datadesc_struct_append(my_type,"data",
297 gras_datadesc_array_dyn ("s_array::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
298 gras_datadesc_struct_close(my_type);
302 * The *_mult versions are intended for multi-dimensional arrays: They multiply their value to the previously pushed one
303 * (by another field callback) and push the result of the multiplication back. An example of use follows. Please note
304 * that the first field needs a regular push callback, not a multiplier one. Think of it as a stacked calculator (man dc(1)).\verbatim
311 my_type=gras_datadesc_struct("s_matrix");
312 gras_datadesc_struct_append(my_type,"row", gras_datadesc_by_name("int"));
313 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int);
314 gras_datadesc_struct_append(my_type,"col", gras_datadesc_by_name("int"));
315 gras_datadesc_cb_field_send (my_type, "length", gras_datadesc_cb_push_int_mult);
317 gras_datadesc_struct_append(my_type,"data",
318 gras_datadesc_array_dyn ("s_matrix::data",gras_datadesc_by_name("int"), gras_datadesc_cb_pop));
319 gras_datadesc_struct_close(my_type);
326 gras_cbps_i_push(gras_cbps_t ps, int val);
328 gras_cbps_i_pop(gras_cbps_t ps);
330 int gras_datadesc_cb_pop(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
332 void gras_datadesc_cb_push_int(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
333 void gras_datadesc_cb_push_uint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
334 void gras_datadesc_cb_push_lint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
335 void gras_datadesc_cb_push_ulint(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
337 void gras_datadesc_cb_push_int_mult(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
338 void gras_datadesc_cb_push_uint_mult(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
339 void gras_datadesc_cb_push_lint_mult(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
340 void gras_datadesc_cb_push_ulint_mult(gras_datadesc_type_t typedesc, gras_cbps_t vars, void *data);
345 /** @name 5. Callback Persistant State: Full featured mechanism
347 * Sometimes, one of the callbacks need to leave information for the next ones. If the simple push/pop mechanism
348 * introduced in previous section isn't enough, you can always use this full featured one.
353 void gras_cbps_v_pop (gras_cbps_t ps,
355 /* OUT */ gras_datadesc_type_t *ddt,
356 /* OUT */ void **res);
357 void gras_cbps_v_push(gras_cbps_t ps,
360 gras_datadesc_type_t ddt);
361 void gras_cbps_v_set (gras_cbps_t ps,
364 gras_datadesc_type_t ddt);
366 void * gras_cbps_v_get (gras_cbps_t ps,
368 /* OUT */ gras_datadesc_type_t *ddt);
370 void gras_cbps_block_begin(gras_cbps_t ps);
371 void gras_cbps_block_end(gras_cbps_t ps);
377 /*******************************
378 **** About data convertion ****
379 *******************************/
380 int gras_arch_selfid(void); /* ID of this arch */
383 /*****************************
384 **** NWS datadescription * FIXME: obsolete?
385 *****************************/
388 * Basic types we can embeed in DataDescriptors.
391 {CHAR_TYPE, DOUBLE_TYPE, FLOAT_TYPE, INT_TYPE, LONG_TYPE, SHORT_TYPE,
392 UNSIGNED_INT_TYPE, UNSIGNED_LONG_TYPE, UNSIGNED_SHORT_TYPE, STRUCT_TYPE}
394 #define SIMPLE_TYPE_COUNT 9
396 /** \brief Describe a collection of data.
398 ** A description of a collection of \a type data. \a repetitions is used only
399 ** for arrays; it contains the number of elements. \a offset is used only for
400 ** struct members in host format; it contains the offset of the member from the
401 ** beginning of the struct, taking into account internal padding added by the
402 ** compiler for alignment purposes. \a members, \a length, and \a tailPadding are
403 ** used only for STRUCT_TYPE data; the \a length -long array \a members describes
404 ** the members of the nested struct, and \a tailPadding indicates how many
405 ** padding bytes the compiler adds to the end of the structure.
408 typedef struct DataDescriptorStruct {
412 /*@null@*/ struct DataDescriptorStruct *members;
416 /** DataDescriptor for an array */
417 #define SIMPLE_DATA(type,repetitions) \
418 {type, repetitions, 0, NULL, 0, 0}
419 /** DataDescriptor for an structure member */
420 #define SIMPLE_MEMBER(type,repetitions,offset) \
421 {type, repetitions, offset, NULL, 0, 0}
422 /** DataDescriptor for padding bytes */
423 #define PAD_BYTES(structType,lastMember,memberType,repetitions) \
424 sizeof(structType) - offsetof(structType, lastMember) - \
425 sizeof(memberType) * repetitions
428 gras_datadesc_import_nws(const char *name,
429 const DataDescriptor *desc,
430 unsigned long howmany);
435 #endif /* GRAS_DATADESC_H */