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