Revision control
Copy as Markdown
Other Tools
/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file ralloc.h
*
* ralloc: a recursive memory allocator
*
* The ralloc memory allocator creates a hierarchy of allocated
* objects. Every allocation is in reference to some parent, and
* every allocated object can in turn be used as the parent of a
* subsequent allocation. This allows for extremely convenient
* discarding of an entire tree/sub-tree of allocations by calling
* ralloc_free on any particular object to free it and all of its
* children.
*
* The conceptual working of ralloc was directly inspired by Andrew
* Tridgell's talloc, but ralloc is an independent implementation
* released under the MIT license and tuned for Mesa.
*
* talloc is more sophisticated than ralloc in that it includes reference
* counting and useful debugging features. However, it is released under
* a non-permissive open source license.
*/
#ifndef RALLOC_H
#define RALLOC_H
#include <stddef.h>
#include <stdarg.h>
#include <stdbool.h>
#include "macros.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* \def ralloc(ctx, type)
* Allocate a new object chained off of the given context.
*
* This is equivalent to:
* \code
* ((type *) ralloc_size(ctx, sizeof(type))
* \endcode
*/
#define ralloc(ctx, type) ((type *) ralloc_size(ctx, sizeof(type)))
/**
* \def rzalloc(ctx, type)
* Allocate a new object out of the given context and initialize it to zero.
*
* This is equivalent to:
* \code
* ((type *) rzalloc_size(ctx, sizeof(type))
* \endcode
*/
#define rzalloc(ctx, type) ((type *) rzalloc_size(ctx, sizeof(type)))
/**
* Allocate a new ralloc context.
*
* While any ralloc'd pointer can be used as a context, sometimes it is useful
* to simply allocate a context with no associated memory.
*
* It is equivalent to:
* \code
* ((type *) ralloc_size(ctx, 0)
* \endcode
*/
void *ralloc_context(const void *ctx);
/**
* Allocate memory chained off of the given context.
*
* This is the core allocation routine which is used by all others. It
* simply allocates storage for \p size bytes and returns the pointer,
* similar to \c malloc.
*/
void *ralloc_size(const void *ctx, size_t size) MALLOCLIKE;
/**
* Allocate zero-initialized memory chained off of the given context.
*
* This is similar to \c calloc with a size of 1.
*/
void *rzalloc_size(const void *ctx, size_t size) MALLOCLIKE;
/**
* Resize a piece of ralloc-managed memory, preserving data.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the memory to be resized. May be NULL.
* \param size The amount of memory to allocate, in bytes.
*/
void *reralloc_size(const void *ctx, void *ptr, size_t size);
/**
* Resize a ralloc-managed array, preserving data and initializing any newly
* allocated data to zero.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the memory to be resized. May be NULL.
* \param old_size The amount of memory in the previous allocation, in bytes.
* \param new_size The amount of memory to allocate, in bytes.
*/
void *rerzalloc_size(const void *ctx, void *ptr,
size_t old_size, size_t new_size);
/// \defgroup array Array Allocators @{
/**
* \def ralloc_array(ctx, type, count)
* Allocate an array of objects chained off the given context.
*
* Similar to \c calloc, but does not initialize the memory to zero.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* This is equivalent to:
* \code
* ((type *) ralloc_array_size(ctx, sizeof(type), count)
* \endcode
*/
#define ralloc_array(ctx, type, count) \
((type *) ralloc_array_size(ctx, sizeof(type), count))
/**
* \def rzalloc_array(ctx, type, count)
* Allocate a zero-initialized array chained off the given context.
*
* Similar to \c calloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* This is equivalent to:
* \code
* ((type *) rzalloc_array_size(ctx, sizeof(type), count)
* \endcode
*/
#define rzalloc_array(ctx, type, count) \
((type *) rzalloc_array_size(ctx, sizeof(type), count))
/**
* \def reralloc(ctx, ptr, type, count)
* Resize a ralloc-managed array, preserving data.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the array to be resized. May be NULL.
* \param type The element type.
* \param count The number of elements to allocate.
*/
#define reralloc(ctx, ptr, type, count) \
((type *) reralloc_array_size(ctx, ptr, sizeof(type), count))
/**
* \def rerzalloc(ctx, ptr, type, count)
* Resize a ralloc-managed array, preserving data and initializing any newly
* allocated data to zero.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the array to be resized. May be NULL.
* \param type The element type.
* \param old_count The number of elements in the previous allocation.
* \param new_count The number of elements to allocate.
*/
#define rerzalloc(ctx, ptr, type, old_count, new_count) \
((type *) rerzalloc_array_size(ctx, ptr, sizeof(type), old_count, new_count))
/**
* Allocate memory for an array chained off the given context.
*
* Similar to \c calloc, but does not initialize the memory to zero.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \p size and \p count. This is necessary for security.
*/
void *ralloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE;
/**
* Allocate a zero-initialized array chained off the given context.
*
* Similar to \c calloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \p size and \p count. This is necessary for security.
*/
void *rzalloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIKE;
/**
* Resize a ralloc-managed array, preserving data.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the array to be resized. May be NULL.
* \param size The size of an individual element.
* \param count The number of elements to allocate.
*
* \return True unless allocation failed.
*/
void *reralloc_array_size(const void *ctx, void *ptr, size_t size,
unsigned count);
/**
* Resize a ralloc-managed array, preserving data and initializing any newly
* allocated data to zero.
*
* Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the
* memory. Instead, it resizes it to a 0-byte ralloc context, just like
* calling ralloc_size(ctx, 0). This is different from talloc.
*
* More than a convenience function, this also checks for integer overflow when
* multiplying \c sizeof(type) and \p count. This is necessary for security.
*
* \param ctx The context to use for new allocation. If \p ptr != NULL,
* it must be the same as ralloc_parent(\p ptr).
* \param ptr Pointer to the array to be resized. May be NULL.
* \param size The size of an individual element.
* \param old_count The number of elements in the previous allocation.
* \param new_count The number of elements to allocate.
*
* \return True unless allocation failed.
*/
void *rerzalloc_array_size(const void *ctx, void *ptr, size_t size,
unsigned old_count, unsigned new_count);
/// @}
/**
* Free a piece of ralloc-managed memory.
*
* This will also free the memory of any children allocated this context.
*/
void ralloc_free(void *ptr);
/**
* "Steal" memory from one context, changing it to another.
*
* This changes \p ptr's context to \p new_ctx. This is quite useful if
* memory is allocated out of a temporary context.
*/
void ralloc_steal(const void *new_ctx, void *ptr);
/**
* Reparent all children from one context to another.
*
* This effectively calls ralloc_steal(new_ctx, child) for all children of \p old_ctx.
*/
void ralloc_adopt(const void *new_ctx, void *old_ctx);
/**
* Return the given pointer's ralloc context.
*/
void *ralloc_parent(const void *ptr);
/**
* Set a callback to occur just before an object is freed.
*/
void ralloc_set_destructor(const void *ptr, void(*destructor)(void *));
/// \defgroup array String Functions @{
/**
* Duplicate a string, allocating the memory from the given context.
*/
char *ralloc_strdup(const void *ctx, const char *str) MALLOCLIKE;
/**
* Duplicate a string, allocating the memory from the given context.
*
* Like \c strndup, at most \p n characters are copied. If \p str is longer
* than \p n characters, \p n are copied, and a termining \c '\0' byte is added.
*/
char *ralloc_strndup(const void *ctx, const char *str, size_t n) MALLOCLIKE;
/**
* Concatenate two strings, allocating the necessary space.
*
* This appends \p str to \p *dest, similar to \c strcat, using ralloc_resize
* to expand \p *dest to the appropriate size. \p dest will be updated to the
* new pointer unless allocation fails.
*
* The result will always be null-terminated.
*
* \return True unless allocation failed.
*/
bool ralloc_strcat(char **dest, const char *str);
/**
* Concatenate two strings, allocating the necessary space.
*
* This appends at most \p n bytes of \p str to \p *dest, using ralloc_resize
* to expand \p *dest to the appropriate size. \p dest will be updated to the
* new pointer unless allocation fails.
*
* The result will always be null-terminated; \p str does not need to be null
* terminated if it is longer than \p n.
*
* \return True unless allocation failed.
*/
bool ralloc_strncat(char **dest, const char *str, size_t n);
/**
* Concatenate two strings, allocating the necessary space.
*
* This appends \p n bytes of \p str to \p *dest, using ralloc_resize
* to expand \p *dest to the appropriate size. \p dest will be updated to the
* new pointer unless allocation fails.
*
* The result will always be null-terminated.
*
* This function differs from ralloc_strcat() and ralloc_strncat() in that it
* does not do any strlen() calls which can become costly on large strings.
*
* \return True unless allocation failed.
*/
bool
ralloc_str_append(char **dest, const char *str,
size_t existing_length, size_t str_size);
/**
* Print to a string.
*
* This is analogous to \c sprintf, but allocates enough space (using \p ctx
* as the context) for the resulting string.
*
* \return The newly allocated string.
*/
char *ralloc_asprintf (const void *ctx, const char *fmt, ...) PRINTFLIKE(2, 3) MALLOCLIKE;
/* Return the length of the string that would be generated by a printf-style
* format and argument list, not including the \0 byte.
*/
size_t printf_length(const char *fmt, va_list untouched_args);
/**
* Print to a string, given a va_list.
*
* This is analogous to \c vsprintf, but allocates enough space (using \p ctx
* as the context) for the resulting string.
*
* \return The newly allocated string.
*/
char *ralloc_vasprintf(const void *ctx, const char *fmt, va_list args) MALLOCLIKE;
/**
* Rewrite the tail of an existing string, starting at a given index.
*
* Overwrites the contents of *str starting at \p start with newly formatted
* text, including a new null-terminator. Allocates more memory as necessary.
*
* This can be used to append formatted text when the length of the existing
* string is already known, saving a strlen() call.
*
* \sa ralloc_asprintf_append
*
* \param str The string to be updated.
* \param start The index to start appending new data at.
* \param fmt A printf-style formatting string
*
* \p str will be updated to the new pointer unless allocation fails.
* \p start will be increased by the length of the newly formatted text.
*
* \return True unless allocation failed.
*/
bool ralloc_asprintf_rewrite_tail(char **str, size_t *start,
const char *fmt, ...)
PRINTFLIKE(3, 4);
/**
* Rewrite the tail of an existing string, starting at a given index.
*
* Overwrites the contents of *str starting at \p start with newly formatted
* text, including a new null-terminator. Allocates more memory as necessary.
*
* This can be used to append formatted text when the length of the existing
* string is already known, saving a strlen() call.
*
* \sa ralloc_vasprintf_append
*
* \param str The string to be updated.
* \param start The index to start appending new data at.
* \param fmt A printf-style formatting string
* \param args A va_list containing the data to be formatted
*
* \p str will be updated to the new pointer unless allocation fails.
* \p start will be increased by the length of the newly formatted text.
*
* \return True unless allocation failed.
*/
bool ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt,
va_list args);
/**
* Append formatted text to the supplied string.
*
* This is equivalent to
* \code
* ralloc_asprintf_rewrite_tail(str, strlen(*str), fmt, ...)
* \endcode
*
* \sa ralloc_asprintf
* \sa ralloc_asprintf_rewrite_tail
* \sa ralloc_strcat
*
* \p str will be updated to the new pointer unless allocation fails.
*
* \return True unless allocation failed.
*/
bool ralloc_asprintf_append (char **str, const char *fmt, ...)
PRINTFLIKE(2, 3);
/**
* Append formatted text to the supplied string, given a va_list.
*
* This is equivalent to
* \code
* ralloc_vasprintf_rewrite_tail(str, strlen(*str), fmt, args)
* \endcode
*
* \sa ralloc_vasprintf
* \sa ralloc_vasprintf_rewrite_tail
* \sa ralloc_strcat
*
* \p str will be updated to the new pointer unless allocation fails.
*
* \return True unless allocation failed.
*/
bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args);
/// @}
/**
* Declare C++ new and delete operators which use ralloc.
*
* Placing this macro in the body of a class makes it possible to do:
*
* TYPE *var = new(mem_ctx) TYPE(...);
* delete var;
*
* which is more idiomatic in C++ than calling ralloc.
*/
#define DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(TYPE, ALLOC_FUNC) \
private: \
static void _ralloc_destructor(void *p) \
{ \
reinterpret_cast<TYPE *>(p)->TYPE::~TYPE(); \
} \
public: \
static void* operator new(size_t size, void *mem_ctx) \
{ \
void *p = ALLOC_FUNC(mem_ctx, size); \
assert(p != NULL); \
if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \
ralloc_set_destructor(p, _ralloc_destructor); \
return p; \
} \
\
static void operator delete(void *p) \
{ \
/* The object's destructor is guaranteed to have already been \
* called by the delete operator at this point -- Make sure it's \
* not called again. \
*/ \
if (!HAS_TRIVIAL_DESTRUCTOR(TYPE)) \
ralloc_set_destructor(p, NULL); \
ralloc_free(p); \
}
#define DECLARE_RALLOC_CXX_OPERATORS(type) \
DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, ralloc_size)
#define DECLARE_RZALLOC_CXX_OPERATORS(type) \
DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, rzalloc_size)
#define DECLARE_LINEAR_ALLOC_CXX_OPERATORS(type) \
DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_alloc_child)
#define DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(type) \
DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_zalloc_child)
/**
* Do a fast allocation from the linear buffer, also known as the child node
* from the allocator's point of view. It can't be freed directly. You have
* to free the parent or the ralloc parent.
*
* \param parent parent node of the linear allocator
* \param size size to allocate (max 32 bits)
*/
void *linear_alloc_child(void *parent, unsigned size);
/**
* Allocate a parent node that will hold linear buffers. The returned
* allocation is actually the first child node, but it's also the handle
* of the parent node. Use it for all child node allocations.
*
* \param ralloc_ctx ralloc context, must not be NULL
* \param size size to allocate (max 32 bits)
*/
void *linear_alloc_parent(void *ralloc_ctx, unsigned size);
/**
* Same as linear_alloc_child, but also clears memory.
*/
void *linear_zalloc_child(void *parent, unsigned size);
/**
* Same as linear_alloc_parent, but also clears memory.
*/
void *linear_zalloc_parent(void *ralloc_ctx, unsigned size);
/**
* Free the linear parent node. This will free all child nodes too.
* Freeing the ralloc parent will also free this.
*/
void linear_free_parent(void *ptr);
/**
* Same as ralloc_steal, but steals the linear parent node.
*/
void ralloc_steal_linear_parent(void *new_ralloc_ctx, void *ptr);
/**
* Return the ralloc parent of the linear parent node.
*/
void *ralloc_parent_of_linear_parent(void *ptr);
/**
* Same as realloc except that the linear allocator doesn't free child nodes,
* so it's reduced to memory duplication. It's used in places where
* reallocation is required. Don't use it often. It's much slower than
* realloc.
*/
void *linear_realloc(void *parent, void *old, unsigned new_size);
/* The functions below have the same semantics as their ralloc counterparts,
* except that they always allocate a linear child node.
*/
char *linear_strdup(void *parent, const char *str);
char *linear_asprintf(void *parent, const char *fmt, ...);
char *linear_vasprintf(void *parent, const char *fmt, va_list args);
bool linear_asprintf_append(void *parent, char **str, const char *fmt, ...);
bool linear_vasprintf_append(void *parent, char **str, const char *fmt,
va_list args);
bool linear_asprintf_rewrite_tail(void *parent, char **str, size_t *start,
const char *fmt, ...);
bool linear_vasprintf_rewrite_tail(void *parent, char **str, size_t *start,
const char *fmt, va_list args);
bool linear_strcat(void *parent, char **dest, const char *str);
#ifdef __cplusplus
} /* end of extern "C" */
#endif
#endif