mono/sgen/sgen-cardtable.c

   1 /**
   2  * \file
   3  * Card table implementation for sgen
   4  *
   5  * Author:
   6  *      Rodrigo Kumpera (rkumpera@novell.com)
   7  *
   8  * Copyright 2001-2003 Ximian, Inc
   9  * Copyright 2003-2010 Novell, Inc.
  10  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
  11  * Copyright (C) 2012 Xamarin Inc
  12  *
  13  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  14  */
  15
  16 #include "config.h"
  17 #ifdef HAVE_SGEN_GC
  18
  19 #include <string.h>
  20
  21 #include "mono/sgen/sgen-gc.h"
  22 #include "mono/sgen/sgen-cardtable.h"
  23 #include "mono/sgen/sgen-memory-governor.h"
  24 #include "mono/sgen/sgen-protocol.h"
  25 #include "mono/sgen/sgen-layout-stats.h"
  26 #include "mono/sgen/sgen-client.h"
  27 #include "mono/sgen/gc-internal-agnostic.h"
  28 #include "mono/utils/mono-memory-model.h"
  29
  30 //#define CARDTABLE_STATS
  31
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35 #ifdef HAVE_SYS_MMAN_H
  36 #include <sys/mman.h>
  37 #endif
  38 #include <sys/types.h>
  39
  40 guint8 *sgen_cardtable;
  41
  42 static gboolean need_mod_union;
  43
  44 #ifdef HEAVY_STATISTICS
  45 guint64 marked_cards;
  46 guint64 scanned_cards;
  47 guint64 scanned_objects;
  48 guint64 remarked_cards;
  49 static guint64 large_objects;
  50 static guint64 bloby_objects;
  51 #endif
  52
  53 mword
  54 sgen_card_table_number_of_cards_in_range (mword address, mword size)
  55 {
  56         mword end = address + MAX (1, size) - 1;
  57         return (end >> CARD_BITS) - (address >> CARD_BITS) + 1;
  58 }
  59
  60 static void
  61 sgen_card_table_wbarrier_set_field (GCObject *obj, gpointer field_ptr, GCObject* value)
  62 {
  63         *(void**)field_ptr = value;
  64         if (need_mod_union || sgen_ptr_in_nursery (value))
  65                 sgen_card_table_mark_address ((mword)field_ptr);
  66         sgen_dummy_use (value);
  67 }
  68
  69 static void
  70 sgen_card_table_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
  71 {
  72         gpointer *dest = (gpointer *)dest_ptr;
  73         gpointer *src = (gpointer *)src_ptr;
  74
  75         /*overlapping that required backward copying*/
  76         if (src < dest && (src + count) > dest) {
  77                 gpointer *start = dest;
  78                 dest += count - 1;
  79                 src += count - 1;
  80
  81                 for (; dest >= start; --src, --dest) {
  82                         gpointer value = *src;
  83                         SGEN_UPDATE_REFERENCE_ALLOW_NULL (dest, value);
  84                         if (need_mod_union || sgen_ptr_in_nursery (value))
  85                                 sgen_card_table_mark_address ((mword)dest);
  86                         sgen_dummy_use (value);
  87                 }
  88         } else {
  89                 gpointer *end = dest + count;
  90                 for (; dest < end; ++src, ++dest) {
  91                         gpointer value = *src;
  92                         SGEN_UPDATE_REFERENCE_ALLOW_NULL (dest, value);
  93                         if (need_mod_union || sgen_ptr_in_nursery (value))
  94                                 sgen_card_table_mark_address ((mword)dest);
  95                         sgen_dummy_use (value);
  96                 }
  97         }
  98 }
  99
 100 static void
 101 sgen_card_table_wbarrier_value_copy (gpointer dest, gpointer src, int count, size_t element_size)
 102 {
 103         size_t size = count * element_size;
 104
 105         TLAB_ACCESS_INIT;
 106         ENTER_CRITICAL_REGION;
 107
 108         mono_gc_memmove_atomic (dest, src, size);
 109         sgen_card_table_mark_range ((mword)dest, size);
 110
 111         EXIT_CRITICAL_REGION;
 112 }
 113
 114 static void
 115 sgen_card_table_wbarrier_object_copy (GCObject* obj, GCObject *src)
 116 {
 117         size_t size = sgen_client_par_object_get_size (SGEN_LOAD_VTABLE_UNCHECKED (obj), obj);
 118
 119         TLAB_ACCESS_INIT;
 120         ENTER_CRITICAL_REGION;
 121
 122         mono_gc_memmove_aligned ((char*)obj + SGEN_CLIENT_OBJECT_HEADER_SIZE, (char*)src + SGEN_CLIENT_OBJECT_HEADER_SIZE,
 123                         size - SGEN_CLIENT_OBJECT_HEADER_SIZE);
 124         sgen_card_table_mark_range ((mword)obj, size);
 125
 126         EXIT_CRITICAL_REGION;
 127 }
 128
 129 static void
 130 sgen_card_table_wbarrier_generic_nostore (gpointer ptr)
 131 {
 132         sgen_card_table_mark_address ((mword)ptr);
 133 }
 134
 135 static void
 136 sgen_card_table_wbarrier_range_copy (gpointer _dest, gpointer _src, int size)
 137 {
 138         GCObject **dest = (GCObject **)_dest;
 139         GCObject **src = (GCObject **)_src;
 140
 141         size_t nursery_bits = sgen_nursery_bits;
 142         char *start = sgen_nursery_start;
 143         G_GNUC_UNUSED char *end = sgen_nursery_end;
 144
 145         /*
 146          * It's cardtable theory time!
 147          * Our cardtable scanning code supports marking any card that an object/valuetype belongs to.
 148          * This function is supposed to be used to copy a range that fully belongs to a single type.
 149          * It must not be used, for example, to copy 2 adjacent VTs in an array.
 150         */
 151         volatile guint8 *card_address = (volatile guint8 *)sgen_card_table_get_card_address ((mword)dest);
 152         while (size) {
 153                 GCObject *value = *src;
 154                 *dest = value;
 155                 if (SGEN_PTR_IN_NURSERY (value, nursery_bits, start, end) || sgen_concurrent_collection_in_progress) {
 156                         *card_address = 1;
 157                         sgen_dummy_use (value);
 158                 }
 159                 ++src;
 160                 ++dest;
 161                 size -= SIZEOF_VOID_P;
 162         }
 163 }
 164
 165 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 166
 167 guint8 *sgen_shadow_cardtable;
 168
 169 #define SGEN_CARDTABLE_END (sgen_cardtable + CARD_COUNT_IN_BYTES)
 170
 171 static gboolean
 172 sgen_card_table_region_begin_scanning (mword start, mword size)
 173 {
 174         mword end = start + size;
 175         /*XXX this can be improved to work on words and have a single loop induction var */
 176         while (start < end) {
 177                 if (sgen_card_table_card_begin_scanning (start))
 178                         return TRUE;
 179                 start += CARD_SIZE_IN_BYTES;
 180         }
 181         return FALSE;
 182 }
 183
 184 #else
 185
 186 static gboolean
 187 sgen_card_table_region_begin_scanning (mword start, mword size)
 188 {
 189         gboolean res = FALSE;
 190         guint8 *card = sgen_card_table_get_card_address (start);
 191         guint8 *end = card + sgen_card_table_number_of_cards_in_range (start, size);
 192
 193         /*XXX this can be improved to work on words and have a branchless body */
 194         while (card != end) {
 195                 if (*card++) {
 196                         res = TRUE;
 197                         break;
 198                 }
 199         }
 200
 201         memset (sgen_card_table_get_card_address (start), 0, size >> CARD_BITS);
 202
 203         return res;
 204 }
 205
 206 #endif
 207
 208 /*FIXME this assumes that major blocks are multiple of 4K which is pretty reasonable */
 209 gboolean
 210 sgen_card_table_get_card_data (guint8 *data_dest, mword address, mword cards)
 211 {
 212         mword *start = (mword*)sgen_card_table_get_card_scan_address (address);
 213         mword *dest = (mword*)data_dest;
 214         mword *end = (mword*)(data_dest + cards);
 215         mword mask = 0;
 216
 217         for (; dest < end; ++dest, ++start) {
 218                 mword v = *start;
 219                 *dest = v;
 220                 mask |= v;
 221
 222 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
 223                 *start = 0;
 224 #endif
 225         }
 226
 227         return mask != 0;
 228 }
 229
 230 void*
 231 sgen_card_table_align_pointer (void *ptr)
 232 {
 233         return (void*)((mword)ptr & ~(CARD_SIZE_IN_BYTES - 1));
 234 }
 235
 236 void
 237 sgen_card_table_mark_range (mword address, mword size)
 238 {
 239         mword num_cards = sgen_card_table_number_of_cards_in_range (address, size);
 240         guint8 *start = sgen_card_table_get_card_address (address);
 241
 242 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 243         /*
 244          * FIXME: There's a theoretical bug here, namely that the card table is allocated so
 245          * far toward the end of the address space that start + num_cards overflows.
 246          */
 247         guint8 *end = start + num_cards;
 248         SGEN_ASSERT (0, num_cards <= CARD_COUNT_IN_BYTES, "How did we get an object larger than the card table?");
 249         if (end > SGEN_CARDTABLE_END) {
 250                 memset (start, 1, SGEN_CARDTABLE_END - start);
 251                 memset (sgen_cardtable, 1, end - SGEN_CARDTABLE_END);
 252                 return;
 253         }
 254 #endif
 255
 256         memset (start, 1, num_cards);
 257 }
 258
 259 static gboolean
 260 sgen_card_table_is_range_marked (guint8 *cards, mword address, mword size)
 261 {
 262         guint8 *end = cards + sgen_card_table_number_of_cards_in_range (address, size);
 263
 264         /*This is safe since this function is only called by code that only passes continuous card blocks*/
 265         while (cards != end) {
 266                 if (*cards++)
 267                         return TRUE;
 268         }
 269         return FALSE;
 270
 271 }
 272
 273 static void
 274 sgen_card_table_record_pointer (gpointer address)
 275 {
 276         *sgen_card_table_get_card_address ((mword)address) = 1;
 277 }
 278
 279 static gboolean
 280 sgen_card_table_find_address (char *addr)
 281 {
 282         return sgen_card_table_address_is_marked ((mword)addr);
 283 }
 284
 285 static gboolean
 286 sgen_card_table_find_address_with_cards (char *cards_start, guint8 *cards, char *addr)
 287 {
 288         cards_start = (char *)sgen_card_table_align_pointer (cards_start);
 289         return cards [(addr - cards_start) >> CARD_BITS];
 290 }
 291
 292 static void
 293 update_mod_union (guint8 *dest, guint8 *start_card, size_t num_cards)
 294 {
 295         int i;
 296         /* Marking from another thread can happen while we mark here */
 297         for (i = 0; i < num_cards; ++i) {
 298                 if (start_card [i])
 299                         dest [i] = 1;
 300         }
 301 }
 302
 303 guint8*
 304 sgen_card_table_alloc_mod_union (char *obj, mword obj_size)
 305 {
 306         size_t num_cards = sgen_card_table_number_of_cards_in_range ((mword) obj, obj_size);
 307         guint8 *mod_union = (guint8 *)sgen_alloc_internal_dynamic (num_cards, INTERNAL_MEM_CARDTABLE_MOD_UNION, TRUE);
 308         memset (mod_union, 0, num_cards);
 309         return mod_union;
 310 }
 311
 312 void
 313 sgen_card_table_free_mod_union (guint8 *mod_union, char *obj, mword obj_size)
 314 {
 315         size_t num_cards = sgen_card_table_number_of_cards_in_range ((mword) obj, obj_size);
 316         sgen_free_internal_dynamic (mod_union, num_cards, INTERNAL_MEM_CARDTABLE_MOD_UNION);
 317 }
 318
 319 void
 320 sgen_card_table_update_mod_union_from_cards (guint8 *dest, guint8 *start_card, size_t num_cards)
 321 {
 322         SGEN_ASSERT (0, dest, "Why don't we have a mod union?");
 323         update_mod_union (dest, start_card, num_cards);
 324 }
 325
 326 void
 327 sgen_card_table_update_mod_union (guint8 *dest, char *obj, mword obj_size, size_t *out_num_cards)
 328 {
 329         guint8 *start_card = sgen_card_table_get_card_address ((mword)obj);
 330 #ifndef SGEN_HAVE_OVERLAPPING_CARDS
 331         guint8 *end_card = sgen_card_table_get_card_address ((mword)obj + obj_size - 1) + 1;
 332 #endif
 333         size_t num_cards;
 334
 335 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 336         size_t rest;
 337
 338         rest = num_cards = sgen_card_table_number_of_cards_in_range ((mword) obj, obj_size);
 339
 340         while (start_card + rest > SGEN_CARDTABLE_END) {
 341                 size_t count = SGEN_CARDTABLE_END - start_card;
 342                 sgen_card_table_update_mod_union_from_cards (dest, start_card, count);
 343                 dest += count;
 344                 rest -= count;
 345                 start_card = sgen_cardtable;
 346         }
 347         num_cards = rest;
 348 #else
 349         num_cards = end_card - start_card;
 350 #endif
 351
 352         sgen_card_table_update_mod_union_from_cards (dest, start_card, num_cards);
 353
 354         if (out_num_cards)
 355                 *out_num_cards = num_cards;
 356 }
 357
 358 /* Preclean cards and saves the cards that need to be scanned afterwards in cards_preclean */
 359 void
 360 sgen_card_table_preclean_mod_union (guint8 *cards, guint8 *cards_preclean, size_t num_cards)
 361 {
 362         size_t i;
 363
 364         memcpy (cards_preclean, cards, num_cards);
 365         for (i = 0; i < num_cards; i++) {
 366                 if (cards_preclean [i]) {
 367                         cards [i] = 0;
 368                 }
 369         }
 370         /*
 371          * When precleaning we need to make sure the card cleaning
 372          * takes place before the object is scanned. If we don't
 373          * do this we could finish scanning the object and, before
 374          * the cleaning of the card takes place, another thread
 375          * could dirty the object, mark the mod_union card only for
 376          * us to clean it back, without scanning the object again.
 377          */
 378         mono_memory_barrier ();
 379 }
 380
 381 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 382
 383 static void
 384 move_cards_to_shadow_table (mword start, mword size)
 385 {
 386         guint8 *from = sgen_card_table_get_card_address (start);
 387         guint8 *to = sgen_card_table_get_shadow_card_address (start);
 388         size_t bytes = sgen_card_table_number_of_cards_in_range (start, size);
 389
 390         if (bytes >= CARD_COUNT_IN_BYTES) {
 391                 memcpy (sgen_shadow_cardtable, sgen_cardtable, CARD_COUNT_IN_BYTES);
 392         } else if (to + bytes > SGEN_SHADOW_CARDTABLE_END) {
 393                 size_t first_chunk = SGEN_SHADOW_CARDTABLE_END - to;
 394                 size_t second_chunk = MIN (CARD_COUNT_IN_BYTES, bytes) - first_chunk;
 395
 396                 memcpy (to, from, first_chunk);
 397                 memcpy (sgen_shadow_cardtable, sgen_cardtable, second_chunk);
 398         } else {
 399                 memcpy (to, from, bytes);
 400         }
 401 }
 402
 403 static void
 404 clear_cards (mword start, mword size)
 405 {
 406         guint8 *addr = sgen_card_table_get_card_address (start);
 407         size_t bytes = sgen_card_table_number_of_cards_in_range (start, size);
 408
 409         if (bytes >= CARD_COUNT_IN_BYTES) {
 410                 memset (sgen_cardtable, 0, CARD_COUNT_IN_BYTES);
 411         } else if (addr + bytes > SGEN_CARDTABLE_END) {
 412                 size_t first_chunk = SGEN_CARDTABLE_END - addr;
 413
 414                 memset (addr, 0, first_chunk);
 415                 memset (sgen_cardtable, 0, bytes - first_chunk);
 416         } else {
 417                 memset (addr, 0, bytes);
 418         }
 419 }
 420
 421
 422 #else
 423
 424 static void
 425 clear_cards (mword start, mword size)
 426 {
 427         memset (sgen_card_table_get_card_address (start), 0, sgen_card_table_number_of_cards_in_range (start, size));
 428 }
 429
 430
 431 #endif
 432
 433 static void
 434 sgen_card_table_clear_cards (void)
 435 {
 436         /*XXX we could do this in 2 ways. using mincore or iterating over all sections/los objects */
 437         sgen_major_collector_iterate_block_ranges (clear_cards);
 438         sgen_los_iterate_live_block_ranges (clear_cards);
 439         sgen_wbroots_iterate_live_block_ranges (clear_cards);
 440 }
 441
 442 static void
 443 sgen_card_table_start_scan_remsets (void)
 444 {
 445 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 446         /*FIXME we should have a bit on each block/los object telling if the object have marked cards.*/
 447         /*First we copy*/
 448         sgen_major_collector_iterate_block_ranges (move_cards_to_shadow_table);
 449         sgen_los_iterate_live_block_ranges (move_cards_to_shadow_table);
 450         sgen_wbroots_iterate_live_block_ranges (move_cards_to_shadow_table);
 451
 452         /*Then we clear*/
 453         sgen_card_table_clear_cards ();
 454 #endif
 455 }
 456
 457 guint8*
 458 sgen_get_card_table_configuration (int *shift_bits, gpointer *mask)
 459 {
 460 #ifndef MANAGED_WBARRIER
 461         return NULL;
 462 #else
 463         if (!sgen_cardtable)
 464                 return NULL;
 465
 466         *shift_bits = CARD_BITS;
 467 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 468         *mask = (gpointer)CARD_MASK;
 469 #else
 470         *mask = NULL;
 471 #endif
 472
 473         return sgen_cardtable;
 474 #endif
 475 }
 476
 477 #if 0
 478 void
 479 sgen_card_table_dump_obj_card (GCObject *object, size_t size, void *dummy)
 480 {
 481         guint8 *start = sgen_card_table_get_card_scan_address (object);
 482         guint8 *end = start + sgen_card_table_number_of_cards_in_range (object, size);
 483         int cnt = 0;
 484         printf ("--obj %p %d cards [%p %p]--", object, size, start, end);
 485         for (; start < end; ++start) {
 486                 if (cnt == 0)
 487                         printf ("\n\t[%p] ", start);
 488                 printf ("%x ", *start);
 489                 ++cnt;
 490                 if (cnt == 8)
 491                         cnt = 0;
 492         }
 493         printf ("\n");
 494 }
 495 #endif
 496
 497 /*
 498  * Cardtable scanning
 499  */
 500
 501 #define MWORD_MASK (sizeof (mword) - 1)
 502
 503 static inline int
 504 find_card_offset (mword card)
 505 {
 506 /*XXX Use assembly as this generates some pretty bad code */
 507 #if (defined(__i386__) || defined(__arm__)) && defined(__GNUC__)
 508         return  (__builtin_ffs (card) - 1) / 8;
 509 #elif (defined(__x86_64__) || defined(__aarch64__)) && defined(__GNUC__)
 510         return (__builtin_ffsll (card) - 1) / 8;
 511 #elif defined(__s390x__)
 512         return (__builtin_ffsll (GUINT64_TO_LE(card)) - 1) / 8;
 513 #else
 514         int i;
 515         guint8 *ptr = (guint8 *) &card;
 516         for (i = 0; i < sizeof (mword); ++i) {
 517                 if (ptr[i])
 518                         return i;
 519         }
 520         return 0;
 521 #endif
 522 }
 523
 524 guint8*
 525 sgen_find_next_card (guint8 *card_data, guint8 *end)
 526 {
 527         mword *cards, *cards_end;
 528         mword card;
 529
 530         while ((((mword)card_data) & MWORD_MASK) && card_data < end) {
 531                 if (*card_data)
 532                         return card_data;
 533                 ++card_data;
 534         }
 535
 536         if (card_data == end)
 537                 return end;
 538
 539         cards = (mword*)card_data;
 540         cards_end = (mword*)((mword)end & ~MWORD_MASK);
 541         while (cards < cards_end) {
 542                 card = *cards;
 543                 if (card)
 544                         return (guint8*)cards + find_card_offset (card);
 545                 ++cards;
 546         }
 547
 548         card_data = (guint8*)cards_end;
 549         while (card_data < end) {
 550                 if (*card_data)
 551                         return card_data;
 552                 ++card_data;
 553         }
 554
 555         return end;
 556 }
 557
 558 void
 559 sgen_cardtable_scan_object (GCObject *obj, mword block_obj_size, guint8 *cards, ScanCopyContext ctx)
 560 {
 561         HEAVY_STAT (++large_objects);
 562
 563         if (sgen_client_cardtable_scan_object (obj, cards, ctx))
 564                 return;
 565
 566         HEAVY_STAT (++bloby_objects);
 567         if (cards) {
 568                 if (sgen_card_table_is_range_marked (cards, (mword)obj, block_obj_size))
 569                         ctx.ops->scan_object (obj, sgen_obj_get_descriptor (obj), ctx.queue);
 570         } else if (sgen_card_table_region_begin_scanning ((mword)obj, block_obj_size)) {
 571                 ctx.ops->scan_object (obj, sgen_obj_get_descriptor (obj), ctx.queue);
 572         }
 573
 574         sgen_binary_protocol_card_scan (obj, sgen_safe_object_get_size (obj));
 575 }
 576
 577 void
 578 sgen_card_table_init (SgenRememberedSet *remset)
 579 {
 580         sgen_cardtable = (guint8 *)sgen_alloc_os_memory (CARD_COUNT_IN_BYTES, (SgenAllocFlags)(SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE), "card table", MONO_MEM_ACCOUNT_SGEN_CARD_TABLE);
 581
 582 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
 583         sgen_shadow_cardtable = (guint8 *)sgen_alloc_os_memory (CARD_COUNT_IN_BYTES, (SgenAllocFlags)(SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE), "shadow card table", MONO_MEM_ACCOUNT_SGEN_SHADOW_CARD_TABLE);
 584 #endif
 585
 586 #ifdef HEAVY_STATISTICS
 587         mono_counters_register ("marked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &marked_cards);
 588         mono_counters_register ("scanned cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &scanned_cards);
 589         mono_counters_register ("remarked cards", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &remarked_cards);
 590
 591         mono_counters_register ("cardtable scanned objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &scanned_objects);
 592         mono_counters_register ("cardtable large objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &large_objects);
 593         mono_counters_register ("cardtable bloby objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &bloby_objects);
 594 #endif
 595
 596         remset->wbarrier_set_field = sgen_card_table_wbarrier_set_field;
 597         remset->wbarrier_arrayref_copy = sgen_card_table_wbarrier_arrayref_copy;
 598         remset->wbarrier_value_copy = sgen_card_table_wbarrier_value_copy;
 599         remset->wbarrier_object_copy = sgen_card_table_wbarrier_object_copy;
 600         remset->wbarrier_generic_nostore = sgen_card_table_wbarrier_generic_nostore;
 601         remset->record_pointer = sgen_card_table_record_pointer;
 602
 603         remset->start_scan_remsets = sgen_card_table_start_scan_remsets;
 604
 605         remset->clear_cards = sgen_card_table_clear_cards;
 606
 607         remset->find_address = sgen_card_table_find_address;
 608         remset->find_address_with_cards = sgen_card_table_find_address_with_cards;
 609         remset->wbarrier_range_copy = sgen_card_table_wbarrier_range_copy;
 610
 611         need_mod_union = sgen_get_major_collector ()->is_concurrent;
 612 }
 613
 614 #endif /*HAVE_SGEN_GC*/