src/glsl/ralloc.c

   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 #include <assert.h>
  25 #include <stdlib.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29 #include <stdint.h>
  30
  31 /* Android defines SIZE_MAX in limits.h, instead of the standard stdint.h */
  32 #ifdef ANDROID
  33 #include <limits.h>
  34 #endif
  35
  36 /* Some versions of MinGW are missing _vscprintf's declaration, although they
  37  * still provide the symbol in the import library. */
  38 #ifdef __MINGW32__
  39 _CRTIMP int _vscprintf(const char *format, va_list argptr);
  40 #endif
  41
  42 #include "ralloc.h"
  43
  44 #ifndef va_copy
  45 #ifdef __va_copy
  46 #define va_copy(dest, src) __va_copy((dest), (src))
  47 #else
  48 #define va_copy(dest, src) (dest) = (src)
  49 #endif
  50 #endif
  51
  52 #define CANARY 0x5A1106
  53
  54 struct ralloc_header
  55 {
  56 #ifdef DEBUG
  57    /* A canary value used to determine whether a pointer is ralloc'd. */
  58    unsigned canary;
  59 #endif
  60
  61    struct ralloc_header *parent;
  62
  63    /* The first child (head of a linked list) */
  64    struct ralloc_header *child;
  65
  66    /* Linked list of siblings */
  67    struct ralloc_header *prev;
  68    struct ralloc_header *next;
  69
  70    void (*destructor)(void *);
  71 };
  72
  73 typedef struct ralloc_header ralloc_header;
  74
  75 static void unlink_block(ralloc_header *info);
  76 static void unsafe_free(ralloc_header *info);
  77
  78 static ralloc_header *
  79 get_header(const void *ptr)
  80 {
  81    ralloc_header *info = (ralloc_header *) (((char *) ptr) -
  82                                             sizeof(ralloc_header));
  83 #ifdef DEBUG
  84    assert(info->canary == CANARY);
  85 #endif
  86    return info;
  87 }
  88
  89 #define PTR_FROM_HEADER(info) (((char *) info) + sizeof(ralloc_header))
  90
  91 static void
  92 add_child(ralloc_header *parent, ralloc_header *info)
  93 {
  94    if (parent != NULL) {
  95       info->parent = parent;
  96       info->next = parent->child;
  97       parent->child = info;
  98
  99       if (info->next != NULL)
 100          info->next->prev = info;
 101    }
 102 }
 103
 104 void *
 105 ralloc_context(const void *ctx)
 106 {
 107    return ralloc_size(ctx, 0);
 108 }
 109
 110 void *
 111 ralloc_size(const void *ctx, size_t size)
 112 {
 113    void *block = calloc(1, size + sizeof(ralloc_header));
 114    ralloc_header *info;
 115    ralloc_header *parent;
 116
 117    if (unlikely(block == NULL))
 118       return NULL;
 119    info = (ralloc_header *) block;
 120    parent = ctx != NULL ? get_header(ctx) : NULL;
 121
 122    add_child(parent, info);
 123
 124 #ifdef DEBUG
 125    info->canary = CANARY;
 126 #endif
 127
 128    return PTR_FROM_HEADER(info);
 129 }
 130
 131 void *
 132 rzalloc_size(const void *ctx, size_t size)
 133 {
 134    void *ptr = ralloc_size(ctx, size);
 135    if (likely(ptr != NULL))
 136       memset(ptr, 0, size);
 137    return ptr;
 138 }
 139
 140 /* helper function - assumes ptr != NULL */
 141 static void *
 142 resize(void *ptr, size_t size)
 143 {
 144    ralloc_header *child, *old, *info;
 145
 146    old = get_header(ptr);
 147    info = realloc(old, size + sizeof(ralloc_header));
 148
 149    if (info == NULL)
 150       return NULL;
 151
 152    /* Update parent and sibling's links to the reallocated node. */
 153    if (info != old && info->parent != NULL) {
 154       if (info->parent->child == old)
 155          info->parent->child = info;
 156
 157       if (info->prev != NULL)
 158          info->prev->next = info;
 159
 160       if (info->next != NULL)
 161          info->next->prev = info;
 162    }
 163
 164    /* Update child->parent links for all children */
 165    for (child = info->child; child != NULL; child = child->next)
 166       child->parent = info;
 167
 168    return PTR_FROM_HEADER(info);
 169 }
 170
 171 void *
 172 reralloc_size(const void *ctx, void *ptr, size_t size)
 173 {
 174    if (unlikely(ptr == NULL))
 175       return ralloc_size(ctx, size);
 176
 177    assert(ralloc_parent(ptr) == ctx);
 178    return resize(ptr, size);
 179 }
 180
 181 void *
 182 ralloc_array_size(const void *ctx, size_t size, unsigned count)
 183 {
 184    if (count > SIZE_MAX/size)
 185       return NULL;
 186
 187    return ralloc_size(ctx, size * count);
 188 }
 189
 190 void *
 191 rzalloc_array_size(const void *ctx, size_t size, unsigned count)
 192 {
 193    if (count > SIZE_MAX/size)
 194       return NULL;
 195
 196    return rzalloc_size(ctx, size * count);
 197 }
 198
 199 void *
 200 reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count)
 201 {
 202    if (count > SIZE_MAX/size)
 203       return NULL;
 204
 205    return reralloc_size(ctx, ptr, size * count);
 206 }
 207
 208 void
 209 ralloc_free(void *ptr)
 210 {
 211    ralloc_header *info;
 212
 213    if (ptr == NULL)
 214       return;
 215
 216    info = get_header(ptr);
 217    unlink_block(info);
 218    unsafe_free(info);
 219 }
 220
 221 static void
 222 unlink_block(ralloc_header *info)
 223 {
 224    /* Unlink from parent & siblings */
 225    if (info->parent != NULL) {
 226       if (info->parent->child == info)
 227          info->parent->child = info->next;
 228
 229       if (info->prev != NULL)
 230          info->prev->next = info->next;
 231
 232       if (info->next != NULL)
 233          info->next->prev = info->prev;
 234    }
 235    info->parent = NULL;
 236    info->prev = NULL;
 237    info->next = NULL;
 238 }
 239
 240 static void
 241 unsafe_free(ralloc_header *info)
 242 {
 243    /* Recursively free any children...don't waste time unlinking them. */
 244    ralloc_header *temp;
 245    while (info->child != NULL) {
 246       temp = info->child;
 247       info->child = temp->next;
 248       unsafe_free(temp);
 249    }
 250
 251    /* Free the block itself.  Call the destructor first, if any. */
 252    if (info->destructor != NULL)
 253       info->destructor(PTR_FROM_HEADER(info));
 254
 255    free(info);
 256 }
 257
 258 void
 259 ralloc_steal(const void *new_ctx, void *ptr)
 260 {
 261    ralloc_header *info, *parent;
 262
 263    if (unlikely(ptr == NULL))
 264       return;
 265
 266    info = get_header(ptr);
 267    parent = get_header(new_ctx);
 268
 269    unlink_block(info);
 270
 271    add_child(parent, info);
 272 }
 273
 274 void *
 275 ralloc_parent(const void *ptr)
 276 {
 277    ralloc_header *info;
 278
 279    if (unlikely(ptr == NULL))
 280       return NULL;
 281
 282    info = get_header(ptr);
 283    return info->parent ? PTR_FROM_HEADER(info->parent) : NULL;
 284 }
 285
 286 static void *autofree_context = NULL;
 287
 288 static void
 289 autofree(void)
 290 {
 291    ralloc_free(autofree_context);
 292 }
 293
 294 void *
 295 ralloc_autofree_context(void)
 296 {
 297    if (unlikely(autofree_context == NULL)) {
 298       autofree_context = ralloc_context(NULL);
 299       atexit(autofree);
 300    }
 301    return autofree_context;
 302 }
 303
 304 void
 305 ralloc_set_destructor(const void *ptr, void(*destructor)(void *))
 306 {
 307    ralloc_header *info = get_header(ptr);
 308    info->destructor = destructor;
 309 }
 310
 311 char *
 312 ralloc_strdup(const void *ctx, const char *str)
 313 {
 314    size_t n;
 315    char *ptr;
 316
 317    if (unlikely(str == NULL))
 318       return NULL;
 319
 320    n = strlen(str);
 321    ptr = ralloc_array(ctx, char, n + 1);
 322    memcpy(ptr, str, n);
 323    ptr[n] = '\0';
 324    return ptr;
 325 }
 326
 327 char *
 328 ralloc_strndup(const void *ctx, const char *str, size_t max)
 329 {
 330    size_t n;
 331    char *ptr;
 332
 333    if (unlikely(str == NULL))
 334       return NULL;
 335
 336    n = strlen(str);
 337    if (n > max)
 338       n = max;
 339
 340    ptr = ralloc_array(ctx, char, n + 1);
 341    memcpy(ptr, str, n);
 342    ptr[n] = '\0';
 343    return ptr;
 344 }
 345
 346 /* helper routine for strcat/strncat - n is the exact amount to copy */
 347 static bool
 348 cat(char **dest, const char *str, size_t n)
 349 {
 350    char *both;
 351    size_t existing_length;
 352    assert(dest != NULL && *dest != NULL);
 353
 354    existing_length = strlen(*dest);
 355    both = resize(*dest, existing_length + n + 1);
 356    if (unlikely(both == NULL))
 357       return false;
 358
 359    memcpy(both + existing_length, str, n);
 360    both[existing_length + n] = '\0';
 361
 362    *dest = both;
 363    return true;
 364 }
 365
 366
 367 bool
 368 ralloc_strcat(char **dest, const char *str)
 369 {
 370    return cat(dest, str, strlen(str));
 371 }
 372
 373 bool
 374 ralloc_strncat(char **dest, const char *str, size_t n)
 375 {
 376    /* Clamp n to the string length */
 377    size_t str_length = strlen(str);
 378    if (str_length < n)
 379       n = str_length;
 380
 381    return cat(dest, str, n);
 382 }
 383
 384 char *
 385 ralloc_asprintf(const void *ctx, const char *fmt, ...)
 386 {
 387    char *ptr;
 388    va_list args;
 389    va_start(args, fmt);
 390    ptr = ralloc_vasprintf(ctx, fmt, args);
 391    va_end(args);
 392    return ptr;
 393 }
 394
 395 /* Return the length of the string that would be generated by a printf-style
 396  * format and argument list, not including the \0 byte.
 397  */
 398 static size_t
 399 printf_length(const char *fmt, va_list untouched_args)
 400 {
 401    int size;
 402    char junk;
 403
 404    /* Make a copy of the va_list so the original caller can still use it */
 405    va_list args;
 406    va_copy(args, untouched_args);
 407
 408 #ifdef _WIN32
 409    /* We need to use _vcsprintf to calculate the size as vsnprintf returns -1
 410     * if the number of characters to write is greater than count.
 411     */
 412    size = _vscprintf(fmt, args);
 413    (void)junk;
 414 #else
 415    size = vsnprintf(&junk, 1, fmt, args);
 416 #endif
 417    assert(size >= 0);
 418
 419    va_end(args);
 420
 421    return size;
 422 }
 423
 424 char *
 425 ralloc_vasprintf(const void *ctx, const char *fmt, va_list args)
 426 {
 427    size_t size = printf_length(fmt, args) + 1;
 428
 429    char *ptr = ralloc_size(ctx, size);
 430    if (ptr != NULL)
 431       vsnprintf(ptr, size, fmt, args);
 432
 433    return ptr;
 434 }
 435
 436 bool
 437 ralloc_asprintf_append(char **str, const char *fmt, ...)
 438 {
 439    bool success;
 440    va_list args;
 441    va_start(args, fmt);
 442    success = ralloc_vasprintf_append(str, fmt, args);
 443    va_end(args);
 444    return success;
 445 }
 446
 447 bool
 448 ralloc_vasprintf_append(char **str, const char *fmt, va_list args)
 449 {
 450    size_t existing_length;
 451    assert(str != NULL);
 452    existing_length = *str ? strlen(*str) : 0;
 453    return ralloc_vasprintf_rewrite_tail(str, &existing_length, fmt, args);
 454 }
 455
 456 bool
 457 ralloc_asprintf_rewrite_tail(char **str, size_t *start, const char *fmt, ...)
 458 {
 459    bool success;
 460    va_list args;
 461    va_start(args, fmt);
 462    success = ralloc_vasprintf_rewrite_tail(str, start, fmt, args);
 463    va_end(args);
 464    return success;
 465 }
 466
 467 bool
 468 ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt,
 469                               va_list args)
 470 {
 471    size_t new_length;
 472    char *ptr;
 473
 474    assert(str != NULL);
 475
 476    if (unlikely(*str == NULL)) {
 477       // Assuming a NULL context is probably bad, but it's expected behavior.
 478       *str = ralloc_vasprintf(NULL, fmt, args);
 479       return true;
 480    }
 481
 482    new_length = printf_length(fmt, args);
 483
 484    ptr = resize(*str, *start + new_length + 1);
 485    if (unlikely(ptr == NULL))
 486       return false;
 487
 488    vsnprintf(ptr + *start, new_length + 1, fmt, args);
 489    *str = ptr;
 490    *start += new_length;
 491    return true;
 492 }