src/glsl/ralloc.h

   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 /**
  25  * \file ralloc.h
  26  *
  27  * ralloc: a recursive memory allocator
  28  *
  29  * The ralloc memory allocator creates a hierarchy of allocated
  30  * objects. Every allocation is in reference to some parent, and
  31  * every allocated object can in turn be used as the parent of a
  32  * subsequent allocation. This allows for extremely convenient
  33  * discarding of an entire tree/sub-tree of allocations by calling
  34  * ralloc_free on any particular object to free it and all of its
  35  * children.
  36  *
  37  * The conceptual working of ralloc was directly inspired by Andrew
  38  * Tridgell's talloc, but ralloc is an independent implementation
  39  * released under the MIT license and tuned for Mesa.
  40  *
  41  * The talloc implementation is available under the GNU Lesser
  42  * General Public License (GNU LGPL), version 3 or later. It is
  43  * more sophisticated than ralloc in that it includes reference
  44  * counting and debugging features. See: http://talloc.samba.org/
  45  */
  46
  47 #ifndef RALLOC_H
  48 #define RALLOC_H
  49
  50 #ifdef __cplusplus
  51 extern "C" {
  52 #endif
  53
  54 #include <stddef.h>
  55 #include <stdarg.h>
  56 #include <stdbool.h>
  57 #include "main/compiler.h"
  58
  59 /**
  60  * \def ralloc(ctx, type)
  61  * Allocate a new object chained off of the given context.
  62  *
  63  * This is equivalent to:
  64  * \code
  65  * ((type *) ralloc_size(ctx, sizeof(type))
  66  * \endcode
  67  */
  68 #define ralloc(ctx, type)  ((type *) ralloc_size(ctx, sizeof(type)))
  69
  70 /**
  71  * \def rzalloc(ctx, type)
  72  * Allocate a new object out of the given context and initialize it to zero.
  73  *
  74  * This is equivalent to:
  75  * \code
  76  * ((type *) rzalloc_size(ctx, sizeof(type))
  77  * \endcode
  78  */
  79 #define rzalloc(ctx, type) ((type *) rzalloc_size(ctx, sizeof(type)))
  80
  81 /**
  82  * Allocate a new ralloc context.
  83  *
  84  * While any ralloc'd pointer can be used as a context, sometimes it is useful
  85  * to simply allocate a context with no associated memory.
  86  *
  87  * It is equivalent to:
  88  * \code
  89  * ((type *) ralloc_size(ctx, 0)
  90  * \endcode
  91  */
  92 void *ralloc_context(const void *ctx);
  93
  94 /**
  95  * Allocate memory chained off of the given context.
  96  *
  97  * This is the core allocation routine which is used by all others.  It
  98  * simply allocates storage for \p size bytes and returns the pointer,
  99  * similar to \c malloc.
 100  */
 101 void *ralloc_size(const void *ctx, size_t size);
 102
 103 /**
 104  * Allocate zero-initialized memory chained off of the given context.
 105  *
 106  * This is similar to \c calloc with a size of 1.
 107  */
 108 void *rzalloc_size(const void *ctx, size_t size);
 109
 110 /**
 111  * Resize a piece of ralloc-managed memory, preserving data.
 112  *
 113  * Similar to \c realloc.  Unlike C89, passing 0 for \p size does not free the
 114  * memory.  Instead, it resizes it to a 0-byte ralloc context, just like
 115  * calling ralloc_size(ctx, 0).  This is different from talloc.
 116  *
 117  * \param ctx  The context to use for new allocation.  If \p ptr != NULL,
 118  *             it must be the same as ralloc_parent(\p ptr).
 119  * \param ptr  Pointer to the memory to be resized.  May be NULL.
 120  * \param size The amount of memory to allocate, in bytes.
 121  */
 122 void *reralloc_size(const void *ctx, void *ptr, size_t size);
 123
 124 /// \defgroup array Array Allocators @{
 125
 126 /**
 127  * \def ralloc_array(ctx, type, count)
 128  * Allocate an array of objects chained off the given context.
 129  *
 130  * Similar to \c calloc, but does not initialize the memory to zero.
 131  *
 132  * More than a convenience function, this also checks for integer overflow when
 133  * multiplying \c sizeof(type) and \p count.  This is necessary for security.
 134  *
 135  * This is equivalent to:
 136  * \code
 137  * ((type *) ralloc_array_size(ctx, sizeof(type), count)
 138  * \endcode
 139  */
 140 #define ralloc_array(ctx, type, count) \
 141    ((type *) ralloc_array_size(ctx, sizeof(type), count))
 142
 143 /**
 144  * \def rzalloc_array(ctx, type, count)
 145  * Allocate a zero-initialized array chained off the given context.
 146  *
 147  * Similar to \c calloc.
 148  *
 149  * More than a convenience function, this also checks for integer overflow when
 150  * multiplying \c sizeof(type) and \p count.  This is necessary for security.
 151  *
 152  * This is equivalent to:
 153  * \code
 154  * ((type *) rzalloc_array_size(ctx, sizeof(type), count)
 155  * \endcode
 156  */
 157 #define rzalloc_array(ctx, type, count) \
 158    ((type *) rzalloc_array_size(ctx, sizeof(type), count))
 159
 160 /**
 161  * \def reralloc(ctx, ptr, type, count)
 162  * Resize a ralloc-managed array, preserving data.
 163  *
 164  * Similar to \c realloc.  Unlike C89, passing 0 for \p size does not free the
 165  * memory.  Instead, it resizes it to a 0-byte ralloc context, just like
 166  * calling ralloc_size(ctx, 0).  This is different from talloc.
 167  *
 168  * More than a convenience function, this also checks for integer overflow when
 169  * multiplying \c sizeof(type) and \p count.  This is necessary for security.
 170  *
 171  * \param ctx   The context to use for new allocation.  If \p ptr != NULL,
 172  *              it must be the same as ralloc_parent(\p ptr).
 173  * \param ptr   Pointer to the array to be resized.  May be NULL.
 174  * \param type  The element type.
 175  * \param count The number of elements to allocate.
 176  */
 177 #define reralloc(ctx, ptr, type, count) \
 178    ((type *) reralloc_array_size(ctx, ptr, sizeof(type), count))
 179
 180 /**
 181  * Allocate memory for an array chained off the given context.
 182  *
 183  * Similar to \c calloc, but does not initialize the memory to zero.
 184  *
 185  * More than a convenience function, this also checks for integer overflow when
 186  * multiplying \p size and \p count.  This is necessary for security.
 187  */
 188 void *ralloc_array_size(const void *ctx, size_t size, unsigned count);
 189
 190 /**
 191  * Allocate a zero-initialized array chained off the given context.
 192  *
 193  * Similar to \c calloc.
 194  *
 195  * More than a convenience function, this also checks for integer overflow when
 196  * multiplying \p size and \p count.  This is necessary for security.
 197  */
 198 void *rzalloc_array_size(const void *ctx, size_t size, unsigned count);
 199
 200 /**
 201  * Resize a ralloc-managed array, preserving data.
 202  *
 203  * Similar to \c realloc.  Unlike C89, passing 0 for \p size does not free the
 204  * memory.  Instead, it resizes it to a 0-byte ralloc context, just like
 205  * calling ralloc_size(ctx, 0).  This is different from talloc.
 206  *
 207  * More than a convenience function, this also checks for integer overflow when
 208  * multiplying \c sizeof(type) and \p count.  This is necessary for security.
 209  *
 210  * \param ctx   The context to use for new allocation.  If \p ptr != NULL,
 211  *              it must be the same as ralloc_parent(\p ptr).
 212  * \param ptr   Pointer to the array to be resized.  May be NULL.
 213  * \param size  The size of an individual element.
 214  * \param count The number of elements to allocate.
 215  *
 216  * \return True unless allocation failed.
 217  */
 218 void *reralloc_array_size(const void *ctx, void *ptr, size_t size,
 219                           unsigned count);
 220 /// @}
 221
 222 /**
 223  * Free a piece of ralloc-managed memory.
 224  *
 225  * This will also free the memory of any children allocated this context.
 226  */
 227 void ralloc_free(void *ptr);
 228
 229 /**
 230  * "Steal" memory from one context, changing it to another.
 231  *
 232  * This changes \p ptr's context to \p new_ctx.  This is quite useful if
 233  * memory is allocated out of a temporary context.
 234  */
 235 void ralloc_steal(const void *new_ctx, void *ptr);
 236
 237 /**
 238  * Return the given pointer's ralloc context.
 239  */
 240 void *ralloc_parent(const void *ptr);
 241
 242 /**
 243  * Return a context whose memory will be automatically freed at program exit.
 244  *
 245  * The first call to this function creates a context and registers a handler
 246  * to free it using \c atexit.  This may cause trouble if used in a library
 247  * loaded with \c dlopen.
 248  */
 249 void *ralloc_autofree_context(void);
 250
 251 /**
 252  * Set a callback to occur just before an object is freed.
 253  */
 254 void ralloc_set_destructor(const void *ptr, void(*destructor)(void *));
 255
 256 /// \defgroup array String Functions @{
 257 /**
 258  * Duplicate a string, allocating the memory from the given context.
 259  */
 260 char *ralloc_strdup(const void *ctx, const char *str);
 261
 262 /**
 263  * Duplicate a string, allocating the memory from the given context.
 264  *
 265  * Like \c strndup, at most \p n characters are copied.  If \p str is longer
 266  * than \p n characters, \p n are copied, and a termining \c '\0' byte is added.
 267  */
 268 char *ralloc_strndup(const void *ctx, const char *str, size_t n);
 269
 270 /**
 271  * Concatenate two strings, allocating the necessary space.
 272  *
 273  * This appends \p str to \p *dest, similar to \c strcat, using ralloc_resize
 274  * to expand \p *dest to the appropriate size.  \p dest will be updated to the
 275  * new pointer unless allocation fails.
 276  *
 277  * The result will always be null-terminated.
 278  *
 279  * \return True unless allocation failed.
 280  */
 281 bool ralloc_strcat(char **dest, const char *str);
 282
 283 /**
 284  * Concatenate two strings, allocating the necessary space.
 285  *
 286  * This appends at most \p n bytes of \p str to \p *dest, using ralloc_resize
 287  * to expand \p *dest to the appropriate size.  \p dest will be updated to the
 288  * new pointer unless allocation fails.
 289  *
 290  * The result will always be null-terminated; \p str does not need to be null
 291  * terminated if it is longer than \p n.
 292  *
 293  * \return True unless allocation failed.
 294  */
 295 bool ralloc_strncat(char **dest, const char *str, size_t n);
 296
 297 /**
 298  * Print to a string.
 299  *
 300  * This is analogous to \c sprintf, but allocates enough space (using \p ctx
 301  * as the context) for the resulting string.
 302  *
 303  * \return The newly allocated string.
 304  */
 305 char *ralloc_asprintf (const void *ctx, const char *fmt, ...) PRINTFLIKE(2, 3);
 306
 307 /**
 308  * Print to a string, given a va_list.
 309  *
 310  * This is analogous to \c vsprintf, but allocates enough space (using \p ctx
 311  * as the context) for the resulting string.
 312  *
 313  * \return The newly allocated string.
 314  */
 315 char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args);
 316
 317 /**
 318  * Rewrite the tail of an existing string, starting at a given index.
 319  *
 320  * Overwrites the contents of *str starting at \p start with newly formatted
 321  * text, including a new null-terminator.  Allocates more memory as necessary.
 322  *
 323  * This can be used to append formatted text when the length of the existing
 324  * string is already known, saving a strlen() call.
 325  *
 326  * \sa ralloc_asprintf_append
 327  *
 328  * \param str   The string to be updated.
 329  * \param start The index to start appending new data at.
 330  * \param fmt   A printf-style formatting string
 331  *
 332  * \p str will be updated to the new pointer unless allocation fails.
 333  * \p start will be increased by the length of the newly formatted text.
 334  *
 335  * \return True unless allocation failed.
 336  */
 337 bool ralloc_asprintf_rewrite_tail(char **str, size_t *start,
 338                                   const char *fmt, ...)
 339                                   PRINTFLIKE(3, 4);
 340
 341 /**
 342  * Rewrite the tail of an existing string, starting at a given index.
 343  *
 344  * Overwrites the contents of *str starting at \p start with newly formatted
 345  * text, including a new null-terminator.  Allocates more memory as necessary.
 346  *
 347  * This can be used to append formatted text when the length of the existing
 348  * string is already known, saving a strlen() call.
 349  *
 350  * \sa ralloc_vasprintf_append
 351  *
 352  * \param str   The string to be updated.
 353  * \param start The index to start appending new data at.
 354  * \param fmt   A printf-style formatting string
 355  * \param args  A va_list containing the data to be formatted
 356  *
 357  * \p str will be updated to the new pointer unless allocation fails.
 358  * \p start will be increased by the length of the newly formatted text.
 359  *
 360  * \return True unless allocation failed.
 361  */
 362 bool ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt,
 363                                    va_list args);
 364
 365 /**
 366  * Append formatted text to the supplied string.
 367  *
 368  * This is equivalent to
 369  * \code
 370  * ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...)
 371  * \endcode
 372  *
 373  * \sa ralloc_asprintf
 374  * \sa ralloc_asprintf_rewrite_tail
 375  * \sa ralloc_strcat
 376  *
 377  * \p str will be updated to the new pointer unless allocation fails.
 378  *
 379  * \return True unless allocation failed.
 380  */
 381 bool ralloc_asprintf_append (char **str, const char *fmt, ...)
 382                              PRINTFLIKE(2, 3);
 383
 384 /**
 385  * Append formatted text to the supplied string, given a va_list.
 386  *
 387  * This is equivalent to
 388  * \code
 389  * ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args)
 390  * \endcode
 391  *
 392  * \sa ralloc_vasprintf
 393  * \sa ralloc_vasprintf_rewrite_tail
 394  * \sa ralloc_strcat
 395  *
 396  * \p str will be updated to the new pointer unless allocation fails.
 397  *
 398  * \return True unless allocation failed.
 399  */
 400 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args);
 401 /// @}
 402
 403 #ifdef __cplusplus
 404 } /* end of extern "C" */
 405 #endif
 406
 407 /**
 408  * Declare C++ new and delete operators which use ralloc.
 409  *
 410  * Placing this macro in the body of a class makes it possible to do:
 411  *
 412  * TYPE *var = new(mem_ctx) TYPE(...);
 413  * delete var;
 414  *
 415  * which is more idiomatic in C++ than calling ralloc.
 416  */
 417 #define DECLARE_RALLOC_CXX_OPERATORS(TYPE)                               \
 418    static void* operator new(size_t size, void *mem_ctx)                 \
 419    {                                                                     \
 420       void *p = ralloc_size(mem_ctx, size);                              \
 421       assert(p != NULL);                                                 \
 422       return p;                                                          \
 423    }                                                                     \
 424                                                                          \
 425    static void operator delete(void *p)                                  \
 426    {                                                                     \
 427       ralloc_free(p);                                                    \
 428    }
 429
 430
 431 #endif