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