1 /* 2 * Copyright © 2010 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 21 * DEALINGS IN THE SOFTWARE. 22 */ 23 24 /** 25 * \file ralloc.h 26 * 27 * ralloc: a recursive memory allocator 28 * 29 * The ralloc memory allocator creates a hierarchy of allocated 30 * objects. Every allocation is in reference to some parent, and 31 * every allocated object can in turn be used as the parent of a 32 * subsequent allocation. This allows for extremely convenient 33 * discarding of an entire tree/sub-tree of allocations by calling 34 * ralloc_free on any particular object to free it and all of its 35 * children. 36 * 37 * The conceptual working of ralloc was directly inspired by Andrew 38 * Tridgell's talloc, but ralloc is an independent implementation 39 * released under the MIT license and tuned for Mesa. 40 * 41 * talloc is more sophisticated than ralloc in that it includes reference 42 * counting and useful debugging features. However, it is released under 43 * a non-permissive open source license. 44 */ 45 46 #ifndef RALLOC_H 47 #define RALLOC_H 48 49 #include <stddef.h> 50 #include <stdarg.h> 51 #include <stdbool.h> 52 53 #include "macros.h" 54 55 #ifdef __cplusplus 56 extern "C" { 57 #endif 58 59 /** 60 * \def ralloc(ctx, type) 61 * Allocate a new object chained off of the given context. 62 * 63 * This is equivalent to: 64 * \code 65 * ((type *) ralloc_size(ctx, sizeof(type)) 66 * \endcode 67 */ 68 #define ralloc(ctx, type) ((type *) ralloc_size(ctx, sizeof(type))) 69 70 /** 71 * \def rzalloc(ctx, type) 72 * Allocate a new object out of the given context and initialize it to zero. 73 * 74 * This is equivalent to: 75 * \code 76 * ((type *) rzalloc_size(ctx, sizeof(type)) 77 * \endcode 78 */ 79 #define rzalloc(ctx, type) ((type *) rzalloc_size(ctx, sizeof(type))) 80 81 /** 82 * Allocate a new ralloc context. 83 * 84 * While any ralloc'd pointer can be used as a context, sometimes it is useful 85 * to simply allocate a context with no associated memory. 86 * 87 * It is equivalent to: 88 * \code 89 * ((type *) ralloc_size(ctx, 0) 90 * \endcode 91 */ 92 void *ralloc_context(const void *ctx); 93 94 /** 95 * Allocate memory chained off of the given context. 96 * 97 * This is the core allocation routine which is used by all others. It 98 * simply allocates storage for \p size bytes and returns the pointer, 99 * similar to \c malloc. 100 */ 101 void *ralloc_size(const void *ctx, size_t size) MALLOCLIKE; 102 103 /** 104 * Allocate zero-initialized memory chained off of the given context. 105 * 106 * This is similar to \c calloc with a size of 1. 107 */ 108 void *rzalloc_size(const void *ctx, size_t size) MALLOCLIKE; 109 110 /** 111 * Resize a piece of ralloc-managed memory, preserving data. 112 * 113 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 114 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 115 * calling ralloc_size(ctx, 0). This is different from talloc. 116 * 117 * \param ctx The context to use for new allocation. If \p ptr != NULL, 118 * it must be the same as ralloc_parent(\p ptr). 119 * \param ptr Pointer to the memory to be resized. May be NULL. 120 * \param size The amount of memory to allocate, in bytes. 121 */ 122 void *reralloc_size(const void *ctx, void *ptr, size_t size); 123 124 /** 125 * Resize a ralloc-managed array, preserving data and initializing any newly 126 * allocated data to zero. 127 * 128 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 129 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 130 * calling ralloc_size(ctx, 0). This is different from talloc. 131 * 132 * \param ctx The context to use for new allocation. If \p ptr != NULL, 133 * it must be the same as ralloc_parent(\p ptr). 134 * \param ptr Pointer to the memory to be resized. May be NULL. 135 * \param old_size The amount of memory in the previous allocation, in bytes. 136 * \param new_size The amount of memory to allocate, in bytes. 137 */ 138 void *rerzalloc_size(const void *ctx, void *ptr, 139 size_t old_size, size_t new_size); 140 141 /// \defgroup array Array Allocators @{ 142 143 /** 144 * \def ralloc_array(ctx, type, count) 145 * Allocate an array of objects chained off the given context. 146 * 147 * Similar to \c calloc, but does not initialize the memory to zero. 148 * 149 * More than a convenience function, this also checks for integer overflow when 150 * multiplying \c sizeof(type) and \p count. This is necessary for security. 151 * 152 * This is equivalent to: 153 * \code 154 * ((type *) ralloc_array_size(ctx, sizeof(type), count) 155 * \endcode 156 */ 157 #define ralloc_array(ctx, type, count) \ 158 ((type *) ralloc_array_size(ctx, sizeof(type), count)) 159 160 /** 161 * \def rzalloc_array(ctx, type, count) 162 * Allocate a zero-initialized array chained off the given context. 163 * 164 * Similar to \c calloc. 165 * 166 * More than a convenience function, this also checks for integer overflow when 167 * multiplying \c sizeof(type) and \p count. This is necessary for security. 168 * 169 * This is equivalent to: 170 * \code 171 * ((type *) rzalloc_array_size(ctx, sizeof(type), count) 172 * \endcode 173 */ 174 #define rzalloc_array(ctx, type, count) \ 175 ((type *) rzalloc_array_size(ctx, sizeof(type), count)) 176 177 /** 178 * \def reralloc(ctx, ptr, type, count) 179 * Resize a ralloc-managed array, preserving data. 180 * 181 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 182 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 183 * calling ralloc_size(ctx, 0). This is different from talloc. 184 * 185 * More than a convenience function, this also checks for integer overflow when 186 * multiplying \c sizeof(type) and \p count. This is necessary for security. 187 * 188 * \param ctx The context to use for new allocation. If \p ptr != NULL, 189 * it must be the same as ralloc_parent(\p ptr). 190 * \param ptr Pointer to the array to be resized. May be NULL. 191 * \param type The element type. 192 * \param count The number of elements to allocate. 193 */ 194 #define reralloc(ctx, ptr, type, count) \ 195 ((type *) reralloc_array_size(ctx, ptr, sizeof(type), count)) 196 197 /** 198 * \def rerzalloc(ctx, ptr, type, count) 199 * Resize a ralloc-managed array, preserving data and initializing any newly 200 * allocated data to zero. 201 * 202 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 203 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 204 * calling ralloc_size(ctx, 0). This is different from talloc. 205 * 206 * More than a convenience function, this also checks for integer overflow when 207 * multiplying \c sizeof(type) and \p count. This is necessary for security. 208 * 209 * \param ctx The context to use for new allocation. If \p ptr != NULL, 210 * it must be the same as ralloc_parent(\p ptr). 211 * \param ptr Pointer to the array to be resized. May be NULL. 212 * \param type The element type. 213 * \param old_count The number of elements in the previous allocation. 214 * \param new_count The number of elements to allocate. 215 */ 216 #define rerzalloc(ctx, ptr, type, old_count, new_count) \ 217 ((type *) rerzalloc_array_size(ctx, ptr, sizeof(type), old_count, new_count)) 218 219 /** 220 * Allocate memory for an array chained off the given context. 221 * 222 * Similar to \c calloc, but does not initialize the memory to zero. 223 * 224 * More than a convenience function, this also checks for integer overflow when 225 * multiplying \p size and \p count. This is necessary for security. 226 */ 227 void *ralloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE; 228 229 /** 230 * Allocate a zero-initialized array chained off the given context. 231 * 232 * Similar to \c calloc. 233 * 234 * More than a convenience function, this also checks for integer overflow when 235 * multiplying \p size and \p count. This is necessary for security. 236 */ 237 void *rzalloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE; 238 239 /** 240 * Resize a ralloc-managed array, preserving data. 241 * 242 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 243 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 244 * calling ralloc_size(ctx, 0). This is different from talloc. 245 * 246 * More than a convenience function, this also checks for integer overflow when 247 * multiplying \c sizeof(type) and \p count. This is necessary for security. 248 * 249 * \param ctx The context to use for new allocation. If \p ptr != NULL, 250 * it must be the same as ralloc_parent(\p ptr). 251 * \param ptr Pointer to the array to be resized. May be NULL. 252 * \param size The size of an individual element. 253 * \param count The number of elements to allocate. 254 * 255 * \return True unless allocation failed. 256 */ 257 void *reralloc_array_size(const void *ctx, void *ptr, size_t size, 258 unsigned count); 259 260 /** 261 * Resize a ralloc-managed array, preserving data and initializing any newly 262 * allocated data to zero. 263 * 264 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 265 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 266 * calling ralloc_size(ctx, 0). This is different from talloc. 267 * 268 * More than a convenience function, this also checks for integer overflow when 269 * multiplying \c sizeof(type) and \p count. This is necessary for security. 270 * 271 * \param ctx The context to use for new allocation. If \p ptr != NULL, 272 * it must be the same as ralloc_parent(\p ptr). 273 * \param ptr Pointer to the array to be resized. May be NULL. 274 * \param size The size of an individual element. 275 * \param old_count The number of elements in the previous allocation. 276 * \param new_count The number of elements to allocate. 277 * 278 * \return True unless allocation failed. 279 */ 280 void *rerzalloc_array_size(const void *ctx, void *ptr, size_t size, 281 unsigned old_count, unsigned new_count); 282 /// @} 283 284 /** 285 * Free a piece of ralloc-managed memory. 286 * 287 * This will also free the memory of any children allocated this context. 288 */ 289 void ralloc_free(void *ptr); 290 291 /** 292 * "Steal" memory from one context, changing it to another. 293 * 294 * This changes \p ptr's context to \p new_ctx. This is quite useful if 295 * memory is allocated out of a temporary context. 296 */ 297 void ralloc_steal(const void *new_ctx, void *ptr); 298 299 /** 300 * Reparent all children from one context to another. 301 * 302 * This effectively calls ralloc_steal(new_ctx, child) for all children of \p old_ctx. 303 */ 304 void ralloc_adopt(const void *new_ctx, void *old_ctx); 305 306 /** 307 * Return the given pointer's ralloc context. 308 */ 309 void *ralloc_parent(const void *ptr); 310 311 /** 312 * Set a callback to occur just before an object is freed. 313 */ 314 void ralloc_set_destructor(const void *ptr, void(*destructor)(void *)); 315 316 /// \defgroup array String Functions @{ 317 /** 318 * Duplicate a string, allocating the memory from the given context. 319 */ 320 char *ralloc_strdup(const void *ctx, const char *str) MALLOCLIKE; 321 322 /** 323 * Duplicate a string, allocating the memory from the given context. 324 * 325 * Like \c strndup, at most \p n characters are copied. If \p str is longer 326 * than \p n characters, \p n are copied, and a termining \c '\0' byte is added. 327 */ 328 char *ralloc_strndup(const void *ctx, const char *str, size_t n) MALLOCLIKE; 329 330 /** 331 * Concatenate two strings, allocating the necessary space. 332 * 333 * This appends \p str to \p *dest, similar to \c strcat, using ralloc_resize 334 * to expand \p *dest to the appropriate size. \p dest will be updated to the 335 * new pointer unless allocation fails. 336 * 337 * The result will always be null-terminated. 338 * 339 * \return True unless allocation failed. 340 */ 341 bool ralloc_strcat(char **dest, const char *str); 342 343 /** 344 * Concatenate two strings, allocating the necessary space. 345 * 346 * This appends at most \p n bytes of \p str to \p *dest, using ralloc_resize 347 * to expand \p *dest to the appropriate size. \p dest will be updated to the 348 * new pointer unless allocation fails. 349 * 350 * The result will always be null-terminated; \p str does not need to be null 351 * terminated if it is longer than \p n. 352 * 353 * \return True unless allocation failed. 354 */ 355 bool ralloc_strncat(char **dest, const char *str, size_t n); 356 357 /** 358 * Concatenate two strings, allocating the necessary space. 359 * 360 * This appends \p n bytes of \p str to \p *dest, using ralloc_resize 361 * to expand \p *dest to the appropriate size. \p dest will be updated to the 362 * new pointer unless allocation fails. 363 * 364 * The result will always be null-terminated. 365 * 366 * This function differs from ralloc_strcat() and ralloc_strncat() in that it 367 * does not do any strlen() calls which can become costly on large strings. 368 * 369 * \return True unless allocation failed. 370 */ 371 bool 372 ralloc_str_append(char **dest, const char *str, 373 size_t existing_length, size_t str_size); 374 375 /** 376 * Print to a string. 377 * 378 * This is analogous to \c sprintf, but allocates enough space (using \p ctx 379 * as the context) for the resulting string. 380 * 381 * \return The newly allocated string. 382 */ 383 char *ralloc_asprintf (const void *ctx, const char *fmt, ...) PRINTFLIKE(2, 3) MALLOCLIKE; 384 385 /** 386 * Print to a string, given a va_list. 387 * 388 * This is analogous to \c vsprintf, but allocates enough space (using \p ctx 389 * as the context) for the resulting string. 390 * 391 * \return The newly allocated string. 392 */ 393 char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args) MALLOCLIKE; 394 395 /** 396 * Rewrite the tail of an existing string, starting at a given index. 397 * 398 * Overwrites the contents of *str starting at \p start with newly formatted 399 * text, including a new null-terminator. Allocates more memory as necessary. 400 * 401 * This can be used to append formatted text when the length of the existing 402 * string is already known, saving a strlen() call. 403 * 404 * \sa ralloc_asprintf_append 405 * 406 * \param str The string to be updated. 407 * \param start The index to start appending new data at. 408 * \param fmt A printf-style formatting string 409 * 410 * \p str will be updated to the new pointer unless allocation fails. 411 * \p start will be increased by the length of the newly formatted text. 412 * 413 * \return True unless allocation failed. 414 */ 415 bool ralloc_asprintf_rewrite_tail(char **str, size_t *start, 416 const char *fmt, ...) 417 PRINTFLIKE(3, 4); 418 419 /** 420 * Rewrite the tail of an existing string, starting at a given index. 421 * 422 * Overwrites the contents of *str starting at \p start with newly formatted 423 * text, including a new null-terminator. Allocates more memory as necessary. 424 * 425 * This can be used to append formatted text when the length of the existing 426 * string is already known, saving a strlen() call. 427 * 428 * \sa ralloc_vasprintf_append 429 * 430 * \param str The string to be updated. 431 * \param start The index to start appending new data at. 432 * \param fmt A printf-style formatting string 433 * \param args A va_list containing the data to be formatted 434 * 435 * \p str will be updated to the new pointer unless allocation fails. 436 * \p start will be increased by the length of the newly formatted text. 437 * 438 * \return True unless allocation failed. 439 */ 440 bool ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt, 441 va_list args); 442 443 /** 444 * Append formatted text to the supplied string. 445 * 446 * This is equivalent to 447 * \code 448 * ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...) 449 * \endcode 450 * 451 * \sa ralloc_asprintf 452 * \sa ralloc_asprintf_rewrite_tail 453 * \sa ralloc_strcat 454 * 455 * \p str will be updated to the new pointer unless allocation fails. 456 * 457 * \return True unless allocation failed. 458 */ 459 bool ralloc_asprintf_append (char **str, const char *fmt, ...) 460 PRINTFLIKE(2, 3); 461 462 /** 463 * Append formatted text to the supplied string, given a va_list. 464 * 465 * This is equivalent to 466 * \code 467 * ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args) 468 * \endcode 469 * 470 * \sa ralloc_vasprintf 471 * \sa ralloc_vasprintf_rewrite_tail 472 * \sa ralloc_strcat 473 * 474 * \p str will be updated to the new pointer unless allocation fails. 475 * 476 * \return True unless allocation failed. 477 */ 478 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args); 479 /// @} 480 481 /** 482 * Declare C++ new and delete operators which use ralloc. 483 * 484 * Placing this macro in the body of a class makes it possible to do: 485 * 486 * TYPE *var = new(mem_ctx) TYPE(...); 487 * delete var; 488 * 489 * which is more idiomatic in C++ than calling ralloc. 490 */ 491 #define DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(TYPE, ALLOC_FUNC) \ 492 private: \ 493 static void _ralloc_destructor(void *p) \ 494 { \ 495 reinterpret_cast<TYPE *>(p)->TYPE::~TYPE(); \ 496 } \ 497 public: \ 498 static void* operator new(size_t size, void *mem_ctx) \ 499 { \ 500 void *p = ALLOC_FUNC(mem_ctx, size); \ 501 assert(p != NULL); \ 502 if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \ 503 ralloc_set_destructor(p, _ralloc_destructor); \ 504 return p; \ 505 } \ 506 \ 507 static void operator delete(void *p) \ 508 { \ 509 /* The object's destructor is guaranteed to have already been \ 510 * called by the delete operator at this point -- Make sure it's \ 511 * not called again. \ 512 */ \ 513 if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \ 514 ralloc_set_destructor(p, NULL); \ 515 ralloc_free(p); \ 516 } 517 518 #define DECLARE_RALLOC_CXX_OPERATORS(type) \ 519 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, ralloc_size) 520 521 #define DECLARE_RZALLOC_CXX_OPERATORS(type) \ 522 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, rzalloc_size) 523 524 #define DECLARE_LINEAR_ALLOC_CXX_OPERATORS(type) \ 525 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_alloc_child) 526 527 #define DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(type) \ 528 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_zalloc_child) 529 530 531 /** 532 * Do a fast allocation from the linear buffer, also known as the child node 533 * from the allocator's point of view. It can't be freed directly. You have 534 * to free the parent or the ralloc parent. 535 * 536 * \param parent parent node of the linear allocator 537 * \param size size to allocate (max 32 bits) 538 */ 539 void *linear_alloc_child(void *parent, unsigned size); 540 541 /** 542 * Allocate a parent node that will hold linear buffers. The returned 543 * allocation is actually the first child node, but it's also the handle 544 * of the parent node. Use it for all child node allocations. 545 * 546 * \param ralloc_ctx ralloc context, must not be NULL 547 * \param size size to allocate (max 32 bits) 548 */ 549 void *linear_alloc_parent(void *ralloc_ctx, unsigned size); 550 551 /** 552 * Same as linear_alloc_child, but also clears memory. 553 */ 554 void *linear_zalloc_child(void *parent, unsigned size); 555 556 /** 557 * Same as linear_alloc_parent, but also clears memory. 558 */ 559 void *linear_zalloc_parent(void *ralloc_ctx, unsigned size); 560 561 /** 562 * Free the linear parent node. This will free all child nodes too. 563 * Freeing the ralloc parent will also free this. 564 */ 565 void linear_free_parent(void *ptr); 566 567 /** 568 * Same as ralloc_steal, but steals the linear parent node. 569 */ 570 void ralloc_steal_linear_parent(void *new_ralloc_ctx, void *ptr); 571 572 /** 573 * Return the ralloc parent of the linear parent node. 574 */ 575 void *ralloc_parent_of_linear_parent(void *ptr); 576 577 /** 578 * Same as realloc except that the linear allocator doesn't free child nodes, 579 * so it's reduced to memory duplication. It's used in places where 580 * reallocation is required. Don't use it often. It's much slower than 581 * realloc. 582 */ 583 void *linear_realloc(void *parent, void *old, unsigned new_size); 584 585 /* The functions below have the same semantics as their ralloc counterparts, 586 * except that they always allocate a linear child node. 587 */ 588 char *linear_strdup(void *parent, const char *str); 589 char *linear_asprintf(void *parent, const char *fmt, ...); 590 char *linear_vasprintf(void *parent, const char *fmt, va_list args); 591 bool linear_asprintf_append(void *parent, char **str, const char *fmt, ...); 592 bool linear_vasprintf_append(void *parent, char **str, const char *fmt, 593 va_list args); 594 bool linear_asprintf_rewrite_tail(void *parent, char **str, size_t *start, 595 const char *fmt, ...); 596 bool linear_vasprintf_rewrite_tail(void *parent, char **str, size_t *start, 597 const char *fmt, va_list args); 598 bool linear_strcat(void *parent, char **dest, const char *str); 599 600 #ifdef __cplusplus 601 } /* end of extern "C" */ 602 #endif 603 604 #endif 605