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