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 /// \defgroup array Array Allocators @{ 125 126 /** 127 * \def ralloc_array(ctx, type, count) 128 * Allocate an array of objects chained off the given context. 129 * 130 * Similar to \c calloc, but does not initialize the memory to zero. 131 * 132 * More than a convenience function, this also checks for integer overflow when 133 * multiplying \c sizeof(type) and \p count. This is necessary for security. 134 * 135 * This is equivalent to: 136 * \code 137 * ((type *) ralloc_array_size(ctx, sizeof(type), count) 138 * \endcode 139 */ 140 #define ralloc_array(ctx, type, count) \ 141 ((type *) ralloc_array_size(ctx, sizeof(type), count)) 142 143 /** 144 * \def rzalloc_array(ctx, type, count) 145 * Allocate a zero-initialized array chained off the given context. 146 * 147 * Similar to \c calloc. 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 *) rzalloc_array_size(ctx, sizeof(type), count) 155 * \endcode 156 */ 157 #define rzalloc_array(ctx, type, count) \ 158 ((type *) rzalloc_array_size(ctx, sizeof(type), count)) 159 160 /** 161 * \def reralloc(ctx, ptr, type, count) 162 * Resize a ralloc-managed array, preserving data. 163 * 164 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 165 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 166 * calling ralloc_size(ctx, 0). This is different from talloc. 167 * 168 * More than a convenience function, this also checks for integer overflow when 169 * multiplying \c sizeof(type) and \p count. This is necessary for security. 170 * 171 * \param ctx The context to use for new allocation. If \p ptr != NULL, 172 * it must be the same as ralloc_parent(\p ptr). 173 * \param ptr Pointer to the array to be resized. May be NULL. 174 * \param type The element type. 175 * \param count The number of elements to allocate. 176 */ 177 #define reralloc(ctx, ptr, type, count) \ 178 ((type *) reralloc_array_size(ctx, ptr, sizeof(type), count)) 179 180 /** 181 * Allocate memory for an array chained off the given context. 182 * 183 * Similar to \c calloc, but does not initialize the memory to zero. 184 * 185 * More than a convenience function, this also checks for integer overflow when 186 * multiplying \p size and \p count. This is necessary for security. 187 */ 188 void *ralloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE; 189 190 /** 191 * Allocate a zero-initialized array chained off the given context. 192 * 193 * Similar to \c calloc. 194 * 195 * More than a convenience function, this also checks for integer overflow when 196 * multiplying \p size and \p count. This is necessary for security. 197 */ 198 void *rzalloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE; 199 200 /** 201 * Resize a ralloc-managed array, preserving data. 202 * 203 * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the 204 * memory. Instead, it resizes it to a 0-byte ralloc context, just like 205 * calling ralloc_size(ctx, 0). This is different from talloc. 206 * 207 * More than a convenience function, this also checks for integer overflow when 208 * multiplying \c sizeof(type) and \p count. This is necessary for security. 209 * 210 * \param ctx The context to use for new allocation. If \p ptr != NULL, 211 * it must be the same as ralloc_parent(\p ptr). 212 * \param ptr Pointer to the array to be resized. May be NULL. 213 * \param size The size of an individual element. 214 * \param count The number of elements to allocate. 215 * 216 * \return True unless allocation failed. 217 */ 218 void *reralloc_array_size(const void *ctx, void *ptr, size_t size, 219 unsigned count); 220 /// @} 221 222 /** 223 * Free a piece of ralloc-managed memory. 224 * 225 * This will also free the memory of any children allocated this context. 226 */ 227 void ralloc_free(void *ptr); 228 229 /** 230 * "Steal" memory from one context, changing it to another. 231 * 232 * This changes \p ptr's context to \p new_ctx. This is quite useful if 233 * memory is allocated out of a temporary context. 234 */ 235 void ralloc_steal(const void *new_ctx, void *ptr); 236 237 /** 238 * Reparent all children from one context to another. 239 * 240 * This effectively calls ralloc_steal(new_ctx, child) for all children of \p old_ctx. 241 */ 242 void ralloc_adopt(const void *new_ctx, void *old_ctx); 243 244 /** 245 * Return the given pointer's ralloc context. 246 */ 247 void *ralloc_parent(const void *ptr); 248 249 /** 250 * Return a context whose memory will be automatically freed at program exit. 251 * 252 * The first call to this function creates a context and registers a handler 253 * to free it using \c atexit. This may cause trouble if used in a library 254 * loaded with \c dlopen. 255 */ 256 void *ralloc_autofree_context(void); 257 258 /** 259 * Set a callback to occur just before an object is freed. 260 */ 261 void ralloc_set_destructor(const void *ptr, void(*destructor)(void *)); 262 263 /// \defgroup array String Functions @{ 264 /** 265 * Duplicate a string, allocating the memory from the given context. 266 */ 267 char *ralloc_strdup(const void *ctx, const char *str) MALLOCLIKE; 268 269 /** 270 * Duplicate a string, allocating the memory from the given context. 271 * 272 * Like \c strndup, at most \p n characters are copied. If \p str is longer 273 * than \p n characters, \p n are copied, and a termining \c '\0' byte is added. 274 */ 275 char *ralloc_strndup(const void *ctx, const char *str, size_t n) MALLOCLIKE; 276 277 /** 278 * Concatenate two strings, allocating the necessary space. 279 * 280 * This appends \p str to \p *dest, similar to \c strcat, using ralloc_resize 281 * to expand \p *dest to the appropriate size. \p dest will be updated to the 282 * new pointer unless allocation fails. 283 * 284 * The result will always be null-terminated. 285 * 286 * \return True unless allocation failed. 287 */ 288 bool ralloc_strcat(char **dest, const char *str); 289 290 /** 291 * Concatenate two strings, allocating the necessary space. 292 * 293 * This appends at most \p n bytes of \p str to \p *dest, using ralloc_resize 294 * to expand \p *dest to the appropriate size. \p dest will be updated to the 295 * new pointer unless allocation fails. 296 * 297 * The result will always be null-terminated; \p str does not need to be null 298 * terminated if it is longer than \p n. 299 * 300 * \return True unless allocation failed. 301 */ 302 bool ralloc_strncat(char **dest, const char *str, size_t n); 303 304 /** 305 * Print to a string. 306 * 307 * This is analogous to \c sprintf, but allocates enough space (using \p ctx 308 * as the context) for the resulting string. 309 * 310 * \return The newly allocated string. 311 */ 312 char *ralloc_asprintf (const void *ctx, const char *fmt, ...) PRINTFLIKE(2, 3) MALLOCLIKE; 313 314 /** 315 * Print to a string, given a va_list. 316 * 317 * This is analogous to \c vsprintf, but allocates enough space (using \p ctx 318 * as the context) for the resulting string. 319 * 320 * \return The newly allocated string. 321 */ 322 char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args) MALLOCLIKE; 323 324 /** 325 * Rewrite the tail of an existing string, starting at a given index. 326 * 327 * Overwrites the contents of *str starting at \p start with newly formatted 328 * text, including a new null-terminator. Allocates more memory as necessary. 329 * 330 * This can be used to append formatted text when the length of the existing 331 * string is already known, saving a strlen() call. 332 * 333 * \sa ralloc_asprintf_append 334 * 335 * \param str The string to be updated. 336 * \param start The index to start appending new data at. 337 * \param fmt A printf-style formatting string 338 * 339 * \p str will be updated to the new pointer unless allocation fails. 340 * \p start will be increased by the length of the newly formatted text. 341 * 342 * \return True unless allocation failed. 343 */ 344 bool ralloc_asprintf_rewrite_tail(char **str, size_t *start, 345 const char *fmt, ...) 346 PRINTFLIKE(3, 4); 347 348 /** 349 * Rewrite the tail of an existing string, starting at a given index. 350 * 351 * Overwrites the contents of *str starting at \p start with newly formatted 352 * text, including a new null-terminator. Allocates more memory as necessary. 353 * 354 * This can be used to append formatted text when the length of the existing 355 * string is already known, saving a strlen() call. 356 * 357 * \sa ralloc_vasprintf_append 358 * 359 * \param str The string to be updated. 360 * \param start The index to start appending new data at. 361 * \param fmt A printf-style formatting string 362 * \param args A va_list containing the data to be formatted 363 * 364 * \p str will be updated to the new pointer unless allocation fails. 365 * \p start will be increased by the length of the newly formatted text. 366 * 367 * \return True unless allocation failed. 368 */ 369 bool ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt, 370 va_list args); 371 372 /** 373 * Append formatted text to the supplied string. 374 * 375 * This is equivalent to 376 * \code 377 * ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...) 378 * \endcode 379 * 380 * \sa ralloc_asprintf 381 * \sa ralloc_asprintf_rewrite_tail 382 * \sa ralloc_strcat 383 * 384 * \p str will be updated to the new pointer unless allocation fails. 385 * 386 * \return True unless allocation failed. 387 */ 388 bool ralloc_asprintf_append (char **str, const char *fmt, ...) 389 PRINTFLIKE(2, 3); 390 391 /** 392 * Append formatted text to the supplied string, given a va_list. 393 * 394 * This is equivalent to 395 * \code 396 * ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args) 397 * \endcode 398 * 399 * \sa ralloc_vasprintf 400 * \sa ralloc_vasprintf_rewrite_tail 401 * \sa ralloc_strcat 402 * 403 * \p str will be updated to the new pointer unless allocation fails. 404 * 405 * \return True unless allocation failed. 406 */ 407 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args); 408 /// @} 409 410 /** 411 * Declare C++ new and delete operators which use ralloc. 412 * 413 * Placing this macro in the body of a class makes it possible to do: 414 * 415 * TYPE *var = new(mem_ctx) TYPE(...); 416 * delete var; 417 * 418 * which is more idiomatic in C++ than calling ralloc. 419 */ 420 #define DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(TYPE, ALLOC_FUNC) \ 421 private: \ 422 static void _ralloc_destructor(void *p) \ 423 { \ 424 reinterpret_cast<TYPE *>(p)->~TYPE(); \ 425 } \ 426 public: \ 427 static void* operator new(size_t size, void *mem_ctx) \ 428 { \ 429 void *p = ALLOC_FUNC(mem_ctx, size); \ 430 assert(p != NULL); \ 431 if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \ 432 ralloc_set_destructor(p, _ralloc_destructor); \ 433 return p; \ 434 } \ 435 \ 436 static void operator delete(void *p) \ 437 { \ 438 /* The object's destructor is guaranteed to have already been \ 439 * called by the delete operator at this point -- Make sure it's \ 440 * not called again. \ 441 */ \ 442 if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \ 443 ralloc_set_destructor(p, NULL); \ 444 ralloc_free(p); \ 445 } 446 447 #define DECLARE_RALLOC_CXX_OPERATORS(type) \ 448 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, ralloc_size) 449 450 #define DECLARE_RZALLOC_CXX_OPERATORS(type) \ 451 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, rzalloc_size) 452 453 #define DECLARE_LINEAR_ALLOC_CXX_OPERATORS(type) \ 454 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_alloc_child) 455 456 #define DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(type) \ 457 DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_zalloc_child) 458 459 460 /** 461 * Do a fast allocation from the linear buffer, also known as the child node 462 * from the allocator's point of view. It can't be freed directly. You have 463 * to free the parent or the ralloc parent. 464 * 465 * \param parent parent node of the linear allocator 466 * \param size size to allocate (max 32 bits) 467 */ 468 void *linear_alloc_child(void *parent, unsigned size); 469 470 /** 471 * Allocate a parent node that will hold linear buffers. The returned 472 * allocation is actually the first child node, but it's also the handle 473 * of the parent node. Use it for all child node allocations. 474 * 475 * \param ralloc_ctx ralloc context, must not be NULL 476 * \param size size to allocate (max 32 bits) 477 */ 478 void *linear_alloc_parent(void *ralloc_ctx, unsigned size); 479 480 /** 481 * Same as linear_alloc_child, but also clears memory. 482 */ 483 void *linear_zalloc_child(void *parent, unsigned size); 484 485 /** 486 * Same as linear_alloc_parent, but also clears memory. 487 */ 488 void *linear_zalloc_parent(void *ralloc_ctx, unsigned size); 489 490 /** 491 * Free the linear parent node. This will free all child nodes too. 492 * Freeing the ralloc parent will also free this. 493 */ 494 void linear_free_parent(void *ptr); 495 496 /** 497 * Same as ralloc_steal, but steals the linear parent node. 498 */ 499 void ralloc_steal_linear_parent(void *new_ralloc_ctx, void *ptr); 500 501 /** 502 * Return the ralloc parent of the linear parent node. 503 */ 504 void *ralloc_parent_of_linear_parent(void *ptr); 505 506 /** 507 * Same as realloc except that the linear allocator doesn't free child nodes, 508 * so it's reduced to memory duplication. It's used in places where 509 * reallocation is required. Don't use it often. It's much slower than 510 * realloc. 511 */ 512 void *linear_realloc(void *parent, void *old, unsigned new_size); 513 514 /* The functions below have the same semantics as their ralloc counterparts, 515 * except that they always allocate a linear child node. 516 */ 517 char *linear_strdup(void *parent, const char *str); 518 char *linear_asprintf(void *parent, const char *fmt, ...); 519 char *linear_vasprintf(void *parent, const char *fmt, va_list args); 520 bool linear_asprintf_append(void *parent, char **str, const char *fmt, ...); 521 bool linear_vasprintf_append(void *parent, char **str, const char *fmt, 522 va_list args); 523 bool linear_asprintf_rewrite_tail(void *parent, char **str, size_t *start, 524 const char *fmt, ...); 525 bool linear_vasprintf_rewrite_tail(void *parent, char **str, size_t *start, 526 const char *fmt, va_list args); 527 bool linear_strcat(void *parent, char **dest, const char *str); 528 529 #ifdef __cplusplus 530 } /* end of extern "C" */ 531 #endif 532 533 #endif 534