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