#ifndef _TALLOC_H_ #define _TALLOC_H_ /* Unix SMB/CIFS implementation. Samba temporary memory allocation functions Copyright (C) Andrew Tridgell 2004-2005 Copyright (C) Stefan Metzmacher 2006 ** NOTE! The following LGPL license applies to the talloc ** library. This does NOT imply that all of Samba is released ** under the LGPL This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, see <http://www.gnu.org/licenses/>. */ #include <stdlib.h> #include <stdio.h> #include <stdarg.h> #ifdef __cplusplus extern "C" { #endif /** * @defgroup talloc The talloc API * * talloc is a hierarchical, reference counted memory pool system with * destructors. It is the core memory allocator used in Samba. * * @{ */ #define TALLOC_VERSION_MAJOR 2 #define TALLOC_VERSION_MINOR 0 int talloc_version_major(void); int talloc_version_minor(void); /** * @brief Define a talloc parent type * * As talloc is a hierarchial memory allocator, every talloc chunk is a * potential parent to other talloc chunks. So defining a separate type for a * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless, * as it provides an indicator for function arguments. You will frequently * write code like * * @code * struct foo *foo_create(TALLOC_CTX *mem_ctx) * { * struct foo *result; * result = talloc(mem_ctx, struct foo); * if (result == NULL) return NULL; * ... initialize foo ... * return result; * } * @endcode * * In this type of allocating functions it is handy to have a general * TALLOC_CTX type to indicate which parent to put allocated structures on. */ typedef void TALLOC_CTX; /* this uses a little trick to allow __LINE__ to be stringified */ #ifndef __location__ #define __TALLOC_STRING_LINE1__(s) #s #define __TALLOC_STRING_LINE2__(s) __TALLOC_STRING_LINE1__(s) #define __TALLOC_STRING_LINE3__ __TALLOC_STRING_LINE2__(__LINE__) #define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__ #endif #ifndef TALLOC_DEPRECATED #define TALLOC_DEPRECATED 0 #endif #ifndef PRINTF_ATTRIBUTE #if (__GNUC__ >= 3) /** Use gcc attribute to check printf fns. a1 is the 1-based index of * the parameter containing the format, and a2 the index of the first * argument. Note that some gcc 2.x versions don't handle this * properly **/ #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2))) #else #define PRINTF_ATTRIBUTE(a1, a2) #endif #endif #ifdef DOXYGEN /** * @brief Create a new talloc context. * * The talloc() macro is the core of the talloc library. It takes a memory * context and a type, and returns a pointer to a new area of memory of the * given type. * * The returned pointer is itself a talloc context, so you can use it as the * context argument to more calls to talloc if you wish. * * The returned pointer is a "child" of the supplied context. This means that if * you talloc_free() the context then the new child disappears as well. * Alternatively you can free just the child. * * @param[in] ctx A talloc context to create a new reference on or NULL to * create a new top level context. * * @param[in] type The type of memory to allocate. * * @return A type casted talloc context or NULL on error. * * @code * unsigned int *a, *b; * * a = talloc(NULL, unsigned int); * b = talloc(a, unsigned int); * @endcode * * @see talloc_zero * @see talloc_array * @see talloc_steal * @see talloc_free */ void *talloc(const void *ctx, #type); #else #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type) void *_talloc(const void *context, size_t size); #endif /** * @brief Create a new top level talloc context. * * This function creates a zero length named talloc context as a top level * context. It is equivalent to: * * @code * talloc_named(NULL, 0, fmt, ...); * @endcode * @param[in] fmt Format string for the name. * * @param[in] ... Additional printf-style arguments. * * @return The allocated memory chunk, NULL on error. * * @see talloc_named() */ void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2); #ifdef DOXYGEN /** * @brief Free a chunk of talloc memory. * * The talloc_free() function frees a piece of talloc memory, and all its * children. You can call talloc_free() on any pointer returned by * talloc(). * * The return value of talloc_free() indicates success or failure, with 0 * returned for success and -1 for failure. A possible failure condition * is if the pointer had a destructor attached to it and the destructor * returned -1. See talloc_set_destructor() for details on * destructors. Likewise, if "ptr" is NULL, then the function will make * no modifications and return -1. * * If this pointer has an additional parent when talloc_free() is called * then the memory is not actually released, but instead the most * recently established parent is destroyed. See talloc_reference() for * details on establishing additional parents. * * For more control on which parent is removed, see talloc_unlink() * * talloc_free() operates recursively on its children. * * From the 2.0 version of talloc, as a special case, talloc_free() is * refused on pointers that have more than one parent, as talloc would * have no way of knowing which parent should be removed. To free a * pointer that has more than one parent please use talloc_unlink(). * * To help you find problems in your code caused by this behaviour, if * you do try and free a pointer with more than one parent then the * talloc logging function will be called to give output like this: * * @code * ERROR: talloc_free with references at some_dir/source/foo.c:123 * reference at some_dir/source/other.c:325 * reference at some_dir/source/third.c:121 * @endcode * * Please see the documentation for talloc_set_log_fn() and * talloc_set_log_stderr() for more information on talloc logging * functions. * * @param[in] ptr The chunk to be freed. * * @return Returns 0 on success and -1 on error. A possible * failure condition is if the pointer had a destructor * attached to it and the destructor returned -1. Likewise, * if "ptr" is NULL, then the function will make no * modifications and returns -1. * * Example: * @code * unsigned int *a, *b; * a = talloc(NULL, unsigned int); * b = talloc(a, unsigned int); * * talloc_free(a); // Frees a and b * @endcode * * @see talloc_set_destructor() * @see talloc_unlink() */ int talloc_free(void *ptr); #else #define talloc_free(ctx) _talloc_free(ctx, __location__) int _talloc_free(void *ptr, const char *location); #endif /** * @brief Free a talloc chunk's children. * * The function walks along the list of all children of a talloc context and * talloc_free()s only the children, not the context itself. * * @param[in] ptr The chunk that you want to free the children of. */ void talloc_free_children(void *ptr); #ifdef DOXYGEN /** * @brief Assign a destructor function to be called when a chunk is freed. * * The function talloc_set_destructor() sets the "destructor" for the pointer * "ptr". A destructor is a function that is called when the memory used by a * pointer is about to be released. The destructor receives the pointer as an * argument, and should return 0 for success and -1 for failure. * * The destructor can do anything it wants to, including freeing other pieces * of memory. A common use for destructors is to clean up operating system * resources (such as open file descriptors) contained in the structure the * destructor is placed on. * * You can only place one destructor on a pointer. If you need more than one * destructor then you can create a zero-length child of the pointer and place * an additional destructor on that. * * To remove a destructor call talloc_set_destructor() with NULL for the * destructor. * * If your destructor attempts to talloc_free() the pointer that it is the * destructor for then talloc_free() will return -1 and the free will be * ignored. This would be a pointless operation anyway, as the destructor is * only called when the memory is just about to go away. * * @param[in] ptr The talloc chunk to add a destructor to. * * @param[in] destructor The destructor function to be called. NULL to remove * it. * * Example: * @code * static int destroy_fd(int *fd) { * close(*fd); * return 0; * } * * int *open_file(const char *filename) { * int *fd = talloc(NULL, int); * *fd = open(filename, O_RDONLY); * if (*fd < 0) { * talloc_free(fd); * return NULL; * } * // Whenever they free this, we close the file. * talloc_set_destructor(fd, destroy_fd); * return fd; * } * @endcode * * @see talloc() * @see talloc_free() */ void talloc_set_destructor(const void *ptr, int (*destructor)(void *)); /** * @brief Change a talloc chunk's parent. * * The talloc_steal() function changes the parent context of a talloc * pointer. It is typically used when the context that the pointer is * currently a child of is going to be freed and you wish to keep the * memory for a longer time. * * To make the changed hierarchy less error-prone, you might consider to use * talloc_move(). * * If you try and call talloc_steal() on a pointer that has more than one * parent then the result is ambiguous. Talloc will choose to remove the * parent that is currently indicated by talloc_parent() and replace it with * the chosen parent. You will also get a message like this via the talloc * logging functions: * * @code * WARNING: talloc_steal with references at some_dir/source/foo.c:123 * reference at some_dir/source/other.c:325 * reference at some_dir/source/third.c:121 * @endcode * * To unambiguously change the parent of a pointer please see the function * talloc_reparent(). See the talloc_set_log_fn() documentation for more * information on talloc logging. * * @param[in] new_ctx The new parent context. * * @param[in] ptr The talloc chunk to move. * * @return Returns the pointer that you pass it. It does not have * any failure modes. * * @note It is possible to produce loops in the parent/child relationship * if you are not careful with talloc_steal(). No guarantees are provided * as to your sanity or the safety of your data if you do this. */ void *talloc_steal(const void *new_ctx, const void *ptr); #else /* DOXYGEN */ /* try to make talloc_set_destructor() and talloc_steal() type safe, if we have a recent gcc */ #if (__GNUC__ >= 3) #define _TALLOC_TYPEOF(ptr) __typeof__(ptr) #define talloc_set_destructor(ptr, function) \ do { \ int (*_talloc_destructor_fn)(_TALLOC_TYPEOF(ptr)) = (function); \ _talloc_set_destructor((ptr), (int (*)(void *))_talloc_destructor_fn); \ } while(0) /* this extremely strange macro is to avoid some braindamaged warning stupidity in gcc 4.1.x */ #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__); __talloc_steal_ret; }) #else /* __GNUC__ >= 3 */ #define talloc_set_destructor(ptr, function) \ _talloc_set_destructor((ptr), (int (*)(void *))(function)) #define _TALLOC_TYPEOF(ptr) void * #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__) #endif /* __GNUC__ >= 3 */ void _talloc_set_destructor(const void *ptr, int (*_destructor)(void *)); void *_talloc_steal_loc(const void *new_ctx, const void *ptr, const char *location); #endif /* DOXYGEN */ /** * @brief Assign a name to a talloc chunk. * * Each talloc pointer has a "name". The name is used principally for * debugging purposes, although it is also possible to set and get the name on * a pointer in as a way of "marking" pointers in your code. * * The main use for names on pointer is for "talloc reports". See * talloc_report() and talloc_report_full() for details. Also see * talloc_enable_leak_report() and talloc_enable_leak_report_full(). * * The talloc_set_name() function allocates memory as a child of the * pointer. It is logically equivalent to: * * @code * talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...)); * @endcode * * @param[in] ptr The talloc chunk to assign a name to. * * @param[in] fmt Format string for the name. * * @param[in] ... Add printf-style additional arguments. * * @return The assigned name, NULL on error. * * @note Multiple calls to talloc_set_name() will allocate more memory without * releasing the name. All of the memory is released when the ptr is freed * using talloc_free(). */ const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); #ifdef DOXYGEN /** * @brief Change a talloc chunk's parent. * * This function has the same effect as talloc_steal(), and additionally sets * the source pointer to NULL. You would use it like this: * * @code * struct foo *X = talloc(tmp_ctx, struct foo); * struct foo *Y; * Y = talloc_move(new_ctx, &X); * @endcode * * @param[in] new_ctx The new parent context. * * @param[in] ptr Pointer to the talloc chunk to move. * * @return The pointer of the talloc chunk it has been moved to, * NULL on error. */ void *talloc_move(const void *new_ctx, const void *ptr); #else #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr)) void *_talloc_move(const void *new_ctx, const void *pptr); #endif /** * @brief Assign a name to a talloc chunk. * * The function is just like talloc_set_name(), but it takes a string constant, * and is much faster. It is extensively used by the "auto naming" macros, such * as talloc_p(). * * This function does not allocate any memory. It just copies the supplied * pointer into the internal representation of the talloc ptr. This means you * must not pass a name pointer to memory that will disappear before the ptr * is freed with talloc_free(). * * @param[in] ptr The talloc chunk to assign a name to. * * @param[in] name Format string for the name. */ void talloc_set_name_const(const void *ptr, const char *name); /** * @brief Create a named talloc chunk. * * The talloc_named() function creates a named talloc pointer. It is * equivalent to: * * @code * ptr = talloc_size(context, size); * talloc_set_name(ptr, fmt, ....); * @endcode * * @param[in] context The talloc context to hang the result off. * * @param[in] size Number of char's that you want to allocate. * * @param[in] fmt Format string for the name. * * @param[in] ... Additional printf-style arguments. * * @return The allocated memory chunk, NULL on error. * * @see talloc_set_name() */ void *talloc_named(const void *context, size_t size, const char *fmt, ...) PRINTF_ATTRIBUTE(3,4); /** * @brief Basic routine to allocate a chunk of memory. * * This is equivalent to: * * @code * ptr = talloc_size(context, size); * talloc_set_name_const(ptr, name); * @endcode * * @param[in] context The parent context. * * @param[in] size The number of char's that we want to allocate. * * @param[in] name The name the talloc block has. * * @return The allocated memory chunk, NULL on error. */ void *talloc_named_const(const void *context, size_t size, const char *name); #ifdef DOXYGEN /** * @brief Untyped allocation. * * The function should be used when you don't have a convenient type to pass to * talloc(). Unlike talloc(), it is not type safe (as it returns a void *), so * you are on your own for type checking. * * Best to use talloc() or talloc_array() instead. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] size Number of char's that you want to allocate. * * @return The allocated memory chunk, NULL on error. * * Example: * @code * void *mem = talloc_size(NULL, 100); * @endcode */ void *talloc_size(const void *ctx, size_t size); #else #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__) #endif #ifdef DOXYGEN /** * @brief Allocate into a typed pointer. * * The talloc_ptrtype() macro should be used when you have a pointer and want * to allocate memory to point at with this pointer. When compiling with * gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size() and * talloc_get_name() will return the current location in the source file and * not the type. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] type The pointer you want to assign the result to. * * @return The properly casted allocated memory chunk, NULL on * error. * * Example: * @code * unsigned int *a = talloc_ptrtype(NULL, a); * @endcode */ void *talloc_ptrtype(const void *ctx, #type); #else #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr))) #endif #ifdef DOXYGEN /** * @brief Allocate a new 0-sized talloc chunk. * * This is a utility macro that creates a new memory context hanging off an * existing context, automatically naming it "talloc_new: __location__" where * __location__ is the source line it is called from. It is particularly * useful for creating a new temporary working context. * * @param[in] ctx The talloc parent context. * * @return A new talloc chunk, NULL on error. */ void *talloc_new(const void *ctx); #else #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__) #endif #ifdef DOXYGEN /** * @brief Allocate a 0-initizialized structure. * * The macro is equivalent to: * * @code * ptr = talloc(ctx, type); * if (ptr) memset(ptr, 0, sizeof(type)); * @endcode * * @param[in] ctx The talloc context to hang the result off. * * @param[in] type The type that we want to allocate. * * @return Pointer to a piece of memory, properly cast to 'type *', * NULL on error. * * Example: * @code * unsigned int *a, *b; * a = talloc_zero(NULL, unsigned int); * b = talloc_zero(a, unsigned int); * @endcode * * @see talloc() * @see talloc_zero_size() * @see talloc_zero_array() */ void *talloc_zero(const void *ctx, #type); /** * @brief Allocate untyped, 0-initialized memory. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] size Number of char's that you want to allocate. * * @return The allocated memory chunk. */ void *talloc_zero_size(const void *ctx, size_t size); #else #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type) #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__) void *_talloc_zero(const void *ctx, size_t size, const char *name); #endif /** * @brief Return the name of a talloc chunk. * * @param[in] ptr The talloc chunk. * * @return The current name for the given talloc pointer. * * @see talloc_set_name() */ const char *talloc_get_name(const void *ptr); /** * @brief Verify that a talloc chunk carries a specified name. * * This function checks if a pointer has the specified name. If it does * then the pointer is returned. * * @param[in] ptr The talloc chunk to check. * * @param[in] name The name to check against. * * @return The pointer if the name matches, NULL if it doesn't. */ void *talloc_check_name(const void *ptr, const char *name); /** * @brief Get the parent chunk of a pointer. * * @param[in] ptr The talloc pointer to inspect. * * @return The talloc parent of ptr, NULL on error. */ void *talloc_parent(const void *ptr); /** * @brief Get a talloc chunk's parent name. * * @param[in] ptr The talloc pointer to inspect. * * @return The name of ptr's parent chunk. */ const char *talloc_parent_name(const void *ptr); /** * @brief Get the total size of a talloc chunk including its children. * * The function returns the total size in bytes used by this pointer and all * child pointers. Mostly useful for debugging. * * Passing NULL is allowed, but it will only give a meaningful result if * talloc_enable_leak_report() or talloc_enable_leak_report_full() has * been called. * * @param[in] ptr The talloc chunk. * * @return The total size. */ size_t talloc_total_size(const void *ptr); /** * @brief Get the number of talloc chunks hanging off a chunk. * * The talloc_total_blocks() function returns the total memory block * count used by this pointer and all child pointers. Mostly useful for * debugging. * * Passing NULL is allowed, but it will only give a meaningful result if * talloc_enable_leak_report() or talloc_enable_leak_report_full() has * been called. * * @param[in] ptr The talloc chunk. * * @return The total size. */ size_t talloc_total_blocks(const void *ptr); #ifdef DOXYGEN /** * @brief Duplicate a memory area into a talloc chunk. * * The function is equivalent to: * * @code * ptr = talloc_size(ctx, size); * if (ptr) memcpy(ptr, p, size); * @endcode * * @param[in] t The talloc context to hang the result off. * * @param[in] p The memory chunk you want to duplicate. * * @param[in] size Number of char's that you want copy. * * @return The allocated memory chunk. * * @see talloc_size() */ void *talloc_memdup(const void *t, const void *p, size_t size); #else #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__) void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name); #endif #ifdef DOXYGEN /** * @brief Assign a type to a talloc chunk. * * This macro allows you to force the name of a pointer to be a particular type. * This can be used in conjunction with talloc_get_type() to do type checking on * void* pointers. * * It is equivalent to this: * * @code * talloc_set_name_const(ptr, #type) * @endcode * * @param[in] ptr The talloc chunk to assign the type to. * * @param[in] type The type to assign. */ void talloc_set_type(const char *ptr, #type); /** * @brief Get a typed pointer out of a talloc pointer. * * This macro allows you to do type checking on talloc pointers. It is * particularly useful for void* private pointers. It is equivalent to * this: * * @code * (type *)talloc_check_name(ptr, #type) * @endcode * * @param[in] ptr The talloc pointer to check. * * @param[in] type The type to check against. * * @return The properly casted pointer given by ptr, NULL on error. */ type *talloc_get_type(const void *ptr, #type); #else #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type) #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type) #endif #ifdef DOXYGEN /** * @brief Safely turn a void pointer into a typed pointer. * * This macro is used together with talloc(mem_ctx, struct foo). If you had to * assing the talloc chunk pointer to some void pointer variable, * talloc_get_type_abort() is the recommended way to get the convert the void * pointer back to a typed pointer. * * @param[in] ptr The void pointer to convert. * * @param[in] type The type that this chunk contains * * @return The same value as ptr, type-checked and properly cast. */ void *talloc_get_type_abort(const void *ptr, #type); #else #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__) void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location); #endif /** * @brief Find a parent context by name. * * Find a parent memory context of the current context that has the given * name. This can be very useful in complex programs where it may be * difficult to pass all information down to the level you need, but you * know the structure you want is a parent of another context. * * @param[in] ctx The talloc chunk to start from. * * @param[in] name The name of the parent we look for. * * @return The memory context we are looking for, NULL if not * found. */ void *talloc_find_parent_byname(const void *ctx, const char *name); #ifdef DOXYGEN /** * @brief Find a parent context by type. * * Find a parent memory context of the current context that has the given * name. This can be very useful in complex programs where it may be * difficult to pass all information down to the level you need, but you * know the structure you want is a parent of another context. * * Like talloc_find_parent_byname() but takes a type, making it typesafe. * * @param[in] ptr The talloc chunk to start from. * * @param[in] type The type of the parent to look for. * * @return The memory context we are looking for, NULL if not * found. */ void *talloc_find_parent_bytype(const void *ptr, #type); #else #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type) #endif /** * @brief Allocate a talloc pool. * * A talloc pool is a pure optimization for specific situations. In the * release process for Samba 3.2 we found out that we had become considerably * slower than Samba 3.0 was. Profiling showed that malloc(3) was a large CPU * consumer in benchmarks. For Samba 3.2 we have internally converted many * static buffers to dynamically allocated ones, so malloc(3) being beaten * more was no surprise. But it made us slower. * * talloc_pool() is an optimization to call malloc(3) a lot less for the use * pattern Samba has: The SMB protocol is mainly a request/response protocol * where we have to allocate a certain amount of memory per request and free * that after the SMB reply is sent to the client. * * talloc_pool() creates a talloc chunk that you can use as a talloc parent * exactly as you would use any other ::TALLOC_CTX. The difference is that * when you talloc a child of this pool, no malloc(3) is done. Instead, talloc * just increments a pointer inside the talloc_pool. This also works * recursively. If you use the child of the talloc pool as a parent for * grand-children, their memory is also taken from the talloc pool. * * If you talloc_free() children of a talloc pool, the memory is not given * back to the system. Instead, free(3) is only called if the talloc_pool() * itself is released with talloc_free(). * * The downside of a talloc pool is that if you talloc_move() a child of a * talloc pool to a talloc parent outside the pool, the whole pool memory is * not free(3)'ed until that moved chunk is also talloc_free()ed. * * @param[in] context The talloc context to hang the result off. * * @param[in] size Size of the talloc pool. * * @return The allocated talloc pool, NULL on error. */ void *talloc_pool(const void *context, size_t size); /** * @brief Free a talloc chunk and NULL out the pointer. * * TALLOC_FREE() frees a pointer and sets it to NULL. Use this if you want * immediate feedback (i.e. crash) if you use a pointer after having free'ed * it. * * @param[in] ctx The chunk to be freed. */ #define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0) /* @} ******************************************************************/ /** * \defgroup talloc_ref The talloc reference function. * @ingroup talloc * * This module contains the definitions around talloc references * * @{ */ /** * @brief Increase the reference count of a talloc chunk. * * The talloc_increase_ref_count(ptr) function is exactly equivalent to: * * @code * talloc_reference(NULL, ptr); * @endcode * * You can use either syntax, depending on which you think is clearer in * your code. * * @param[in] ptr The pointer to increase the reference count. * * @return 0 on success, -1 on error. */ int talloc_increase_ref_count(const void *ptr); /** * @brief Get the number of references to a talloc chunk. * * @param[in] ptr The pointer to retrieve the reference count from. * * @return The number of references. */ size_t talloc_reference_count(const void *ptr); #ifdef DOXYGEN /** * @brief Create an additional talloc parent to a pointer. * * The talloc_reference() function makes "context" an additional parent of * ptr. Each additional reference consumes around 48 bytes of memory on intel * x86 platforms. * * If ptr is NULL, then the function is a no-op, and simply returns NULL. * * After creating a reference you can free it in one of the following ways: * * - you can talloc_free() any parent of the original pointer. That * will reduce the number of parents of this pointer by 1, and will * cause this pointer to be freed if it runs out of parents. * * - you can talloc_free() the pointer itself. That will destroy the * most recently established parent to the pointer and leave the * pointer as a child of its current parent. * * For more control on which parent to remove, see talloc_unlink() * @param[in] ctx The additional parent. * * @param[in] ptr The pointer you want to create an additional parent for. * * @return The original pointer 'ptr', NULL if talloc ran out of * memory in creating the reference. * * Example: * @code * unsigned int *a, *b, *c; * a = talloc(NULL, unsigned int); * b = talloc(NULL, unsigned int); * c = talloc(a, unsigned int); * // b also serves as a parent of c. * talloc_reference(b, c); * @endcode * * @see talloc_unlink() */ void *talloc_reference(const void *ctx, const void *ptr); #else #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference_loc((ctx),(ptr), __location__) void *_talloc_reference_loc(const void *context, const void *ptr, const char *location); #endif /** * @brief Remove a specific parent from a talloc chunk. * * The function removes a specific parent from ptr. The context passed must * either be a context used in talloc_reference() with this pointer, or must be * a direct parent of ptr. * * Usually you can just use talloc_free() instead of talloc_unlink(), but * sometimes it is useful to have the additional control on which parent is * removed. * * @param[in] context The talloc parent to remove. * * @param[in] ptr The talloc ptr you want to remove the parent from. * * @return 0 on success, -1 on error. * * @note If the parent has already been removed using talloc_free() then * this function will fail and will return -1. Likewise, if ptr is NULL, * then the function will make no modifications and return -1. * * Example: * @code * unsigned int *a, *b, *c; * a = talloc(NULL, unsigned int); * b = talloc(NULL, unsigned int); * c = talloc(a, unsigned int); * // b also serves as a parent of c. * talloc_reference(b, c); * talloc_unlink(b, c); * @endcode */ int talloc_unlink(const void *context, void *ptr); /** * @brief Provide a talloc context that is freed at program exit. * * This is a handy utility function that returns a talloc context * which will be automatically freed on program exit. This can be used * to reduce the noise in memory leak reports. * * Never use this in code that might be used in objects loaded with * dlopen and unloaded with dlclose. talloc_autofree_context() * internally uses atexit(3). Some platforms like modern Linux handles * this fine, but for example FreeBSD does not deal well with dlopen() * and atexit() used simultaneously: dlclose() does not clean up the * list of atexit-handlers, so when the program exits the code that * was registered from within talloc_autofree_context() is gone, the * program crashes at exit. * * @return A talloc context, NULL on error. */ void *talloc_autofree_context(void); /** * @brief Get the size of a talloc chunk. * * This function lets you know the amount of memory alloced so far by * this context. It does NOT account for subcontext memory. * This can be used to calculate the size of an array. * * @param[in] ctx The talloc chunk. * * @return The size of the talloc chunk. */ size_t talloc_get_size(const void *ctx); /** * @brief Show the parentage of a context. * * @param[in] context The talloc context to look at. * * @param[in] file The output to use, a file, stdout or stderr. */ void talloc_show_parents(const void *context, FILE *file); /** * @brief Check if a context is parent of a talloc chunk. * * This checks if context is referenced in the talloc hierarchy above ptr. * * @param[in] context The assumed talloc context. * * @param[in] ptr The talloc chunk to check. * * @return Return 1 if this is the case, 0 if not. */ int talloc_is_parent(const void *context, const void *ptr); /** * @brief Change the parent context of a talloc pointer. * * The function changes the parent context of a talloc pointer. It is typically * used when the context that the pointer is currently a child of is going to be * freed and you wish to keep the memory for a longer time. * * The difference between talloc_reparent() and talloc_steal() is that * talloc_reparent() can specify which parent you wish to change. This is * useful when a pointer has multiple parents via references. * * @param[in] old_parent * @param[in] new_parent * @param[in] ptr * * @return Return the pointer you passed. It does not have any * failure modes. */ void *talloc_reparent(const void *old_parent, const void *new_parent, const void *ptr); /* @} ******************************************************************/ /** * @defgroup talloc_array The talloc array functions * @ingroup talloc * * Talloc contains some handy helpers for handling Arrays conveniently * * @{ */ #ifdef DOXYGEN /** * @brief Allocate an array. * * The macro is equivalent to: * * @code * (type *)talloc_size(ctx, sizeof(type) * count); * @endcode * * except that it provides integer overflow protection for the multiply, * returning NULL if the multiply overflows. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] type The type that we want to allocate. * * @param[in] count The number of 'type' elements you want to allocate. * * @return The allocated result, properly cast to 'type *', NULL on * error. * * Example: * @code * unsigned int *a, *b; * a = talloc_zero(NULL, unsigned int); * b = talloc_array(a, unsigned int, 100); * @endcode * * @see talloc() * @see talloc_zero_array() */ void *talloc_array(const void *ctx, #type, unsigned count); #else #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type) void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name); #endif #ifdef DOXYGEN /** * @brief Allocate an array. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] size The size of an array element. * * @param[in] count The number of elements you want to allocate. * * @return The allocated result, NULL on error. */ void *talloc_array_size(const void *ctx, size_t size, unsigned count); #else #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__) #endif #ifdef DOXYGEN /** * @brief Allocate an array into a typed pointer. * * The macro should be used when you have a pointer to an array and want to * allocate memory of an array to point at with this pointer. When compiling * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_array_size() * and talloc_get_name() will return the current location in the source file * and not the type. * * @param[in] ctx The talloc context to hang the result off. * * @param[in] ptr The pointer you want to assign the result to. * * @param[in] count The number of elements you want to allocate. * * @return The allocated memory chunk, properly casted. NULL on * error. */ void *talloc_array_ptrtype(const void *ctx, const void *ptr, unsigned count); #else #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count) #endif #ifdef DOXYGEN /** * @brief Get the number of elements in a talloc'ed array. * * A talloc chunk carries its own size, so for talloc'ed arrays it is not * necessary to store the number of elements explicitly. * * @param[in] ctx The allocated array. * * @return The number of elements in ctx. */ size_t talloc_array_length(const void *ctx); #else #define talloc_array_length(ctx) (talloc_get_size(ctx)/sizeof(*ctx)) #endif #ifdef DOXYGEN /** * @brief Allocate a zero-initialized array * * @param[in] ctx The talloc context to hang the result off. * * @param[in] type The type that we want to allocate. * * @param[in] count The number of "type" elements you want to allocate. * * @return The allocated result casted to "type *", NULL on error. * * The talloc_zero_array() macro is equivalent to: * * @code * ptr = talloc_array(ctx, type, count); * if (ptr) memset(ptr, sizeof(type) * count); * @endcode */ void *talloc_zero_array(const void *ctx, #type, unsigned count); #else #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type) void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name); #endif #ifdef DOXYGEN /** * @brief Change the size of a talloc array. * * The macro changes the size of a talloc pointer. The 'count' argument is the * number of elements of type 'type' that you want the resulting pointer to * hold. * * talloc_realloc() has the following equivalences: * * @code * talloc_realloc(ctx, NULL, type, 1) ==> talloc(ctx, type); * talloc_realloc(ctx, NULL, type, N) ==> talloc_array(ctx, type, N); * talloc_realloc(ctx, ptr, type, 0) ==> talloc_free(ptr); * @endcode * * The "context" argument is only used if "ptr" is NULL, otherwise it is * ignored. * * @param[in] ctx The parent context used if ptr is NULL. * * @param[in] ptr The chunk to be resized. * * @param[in] type The type of the array element inside ptr. * * @param[in] count The intended number of array elements. * * @return The new array, NULL on error. The call will fail either * due to a lack of memory, or because the pointer has more * than one parent (see talloc_reference()). */ void *talloc_realloc(const void *ctx, void *ptr, #type, size_t count); #else #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type) void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name); #endif #ifdef DOXYGEN /** * @brief Untyped realloc to change the size of a talloc array. * * The macro is useful when the type is not known so the typesafe * talloc_realloc() cannot be used. * * @param[in] ctx The parent context used if 'ptr' is NULL. * * @param[in] ptr The chunk to be resized. * * @param[in] size The new chunk size. * * @return The new array, NULL on error. */ void *talloc_realloc_size(const void *ctx, void *ptr, size_t size); #else #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__) void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name); #endif /** * @brief Provide a function version of talloc_realloc_size. * * This is a non-macro version of talloc_realloc(), which is useful as * libraries sometimes want a ralloc function pointer. A realloc() * implementation encapsulates the functionality of malloc(), free() and * realloc() in one call, which is why it is useful to be able to pass around * a single function pointer. * * @param[in] context The parent context used if ptr is NULL. * * @param[in] ptr The chunk to be resized. * * @param[in] size The new chunk size. * * @return The new chunk, NULL on error. */ void *talloc_realloc_fn(const void *context, void *ptr, size_t size); /* @} ******************************************************************/ /** * @defgroup talloc_string The talloc string functions. * @ingroup talloc * * talloc string allocation and manipulation functions. * @{ */ /** * @brief Duplicate a string into a talloc chunk. * * This function is equivalent to: * * @code * ptr = talloc_size(ctx, strlen(p)+1); * if (ptr) memcpy(ptr, p, strlen(p)+1); * @endcode * * This functions sets the name of the new pointer to the passed * string. This is equivalent to: * * @code * talloc_set_name_const(ptr, ptr) * @endcode * * @param[in] t The talloc context to hang the result off. * * @param[in] p The string you want to duplicate. * * @return The duplicated string, NULL on error. */ char *talloc_strdup(const void *t, const char *p); /** * @brief Append a string to given string and duplicate the result. * * @param[in] s The destination to append to. * * @param[in] a The string you want to append. * * @return The duplicated string, NULL on error. * * @see talloc_strdup() */ char *talloc_strdup_append(char *s, const char *a); /** * @brief Append a string to a given buffer and duplicate the result. * * @param[in] s The destination buffer to append to. * * @param[in] a The string you want to append. * * @return The duplicated string, NULL on error. * * @see talloc_strdup() */ char *talloc_strdup_append_buffer(char *s, const char *a); /** * @brief Duplicate a length-limited string into a talloc chunk. * * This function is the talloc equivalent of the C library function strndup(3). * * This functions sets the name of the new pointer to the passed string. This is * equivalent to: * * @code * talloc_set_name_const(ptr, ptr) * @endcode * * @param[in] t The talloc context to hang the result off. * * @param[in] p The string you want to duplicate. * * @param[in] n The maximum string length to duplicate. * * @return The duplicated string, NULL on error. */ char *talloc_strndup(const void *t, const char *p, size_t n); /** * @brief Append at most n characters of a string to given string and duplicate * the result. * * @param[in] s The destination string to append to. * * @param[in] a The source string you want to append. * * @param[in] n The number of characters you want to append from the * string. * * @return The duplicated string, NULL on error. * * @see talloc_strndup() */ char *talloc_strndup_append(char *s, const char *a, size_t n); /** * @brief Append at most n characters of a string to given buffer and duplicate * the result. * * @param[in] s The destination buffer to append to. * * @param[in] a The source string you want to append. * * @param[in] n The number of characters you want to append from the * string. * * @return The duplicated string, NULL on error. * * @see talloc_strndup() */ char *talloc_strndup_append_buffer(char *s, const char *a, size_t n); /** * @brief Format a string given a va_list. * * This function is the talloc equivalent of the C library function * vasprintf(3). * * This functions sets the name of the new pointer to the new string. This is * equivalent to: * * @code * talloc_set_name_const(ptr, ptr) * @endcode * * @param[in] t The talloc context to hang the result off. * * @param[in] fmt The format string. * * @param[in] ap The parameters used to fill fmt. * * @return The formatted string, NULL on error. */ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); /** * @brief Format a string given a va_list and append it to the given destination * string. * * @param[in] s The destination string to append to. * * @param[in] fmt The format string. * * @param[in] ap The parameters used to fill fmt. * * @return The formatted string, NULL on error. * * @see talloc_vasprintf() */ char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); /** * @brief Format a string given a va_list and append it to the given destination * buffer. * * @param[in] s The destination buffer to append to. * * @param[in] fmt The format string. * * @param[in] ap The parameters used to fill fmt. * * @return The formatted string, NULL on error. * * @see talloc_vasprintf() */ char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); /** * @brief Format a string. * * This function is the talloc equivalent of the C library function asprintf(3). * * This functions sets the name of the new pointer to the new string. This is * equivalent to: * * @code * talloc_set_name_const(ptr, ptr) * @endcode * * @param[in] t The talloc context to hang the result off. * * @param[in] fmt The format string. * * @param[in] ... The parameters used to fill fmt. * * @return The formatted string, NULL on error. */ char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); /** * @brief Append a formatted string to another string. * * This function appends the given formatted string to the given string. Use * this varient when the string in the current talloc buffer may have been * truncated in length. * * This functions sets the name of the new pointer to the new * string. This is equivalent to: * * @code * talloc_set_name_const(ptr, ptr) * @endcode * * @param[in] s The string to append to. * * @param[in] fmt The format string. * * @param[in] ... The parameters used to fill fmt. * * @return The formatted string, NULL on error. */ char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); /** * @brief Append a formatted string to another string. * * @param[in] s The string to append to * * @param[in] fmt The format string. * * @param[in] ... The parameters used to fill fmt. * * @return The formatted string, NULL on error. */ char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); /* @} ******************************************************************/ /** * @defgroup talloc_debug The talloc debugging support functions * @ingroup talloc * * To aid memory debugging, talloc contains routines to inspect the currently * allocated memory hierarchy. * * @{ */ /** * @brief Walk a complete talloc hierarchy. * * This provides a more flexible reports than talloc_report(). It * will recursively call the callback for the entire tree of memory * referenced by the pointer. References in the tree are passed with * is_ref = 1 and the pointer that is referenced. * * You can pass NULL for the pointer, in which case a report is * printed for the top level memory context, but only if * talloc_enable_leak_report() or talloc_enable_leak_report_full() * has been called. * * The recursion is stopped when depth >= max_depth. * max_depth = -1 means only stop at leaf nodes. * * @param[in] ptr The talloc chunk. * * @param[in] depth Internal parameter to control recursion. Call with 0. * * @param[in] max_depth Maximum recursion level. * * @param[in] callback Function to be called on every chunk. * * @param[in] private_data Private pointer passed to callback. */ void talloc_report_depth_cb(const void *ptr, int depth, int max_depth, void (*callback)(const void *ptr, int depth, int max_depth, int is_ref, void *private_data), void *private_data); /** * @brief Print a talloc hierarchy. * * This provides a more flexible reports than talloc_report(). It * will let you specify the depth and max_depth. * * @param[in] ptr The talloc chunk. * * @param[in] depth Internal parameter to control recursion. Call with 0. * * @param[in] max_depth Maximum recursion level. * * @param[in] f The file handle to print to. */ void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f); /** * @brief Print a summary report of all memory used by ptr. * * This provides a more detailed report than talloc_report(). It will * recursively print the ensire tree of memory referenced by the * pointer. References in the tree are shown by giving the name of the * pointer that is referenced. * * You can pass NULL for the pointer, in which case a report is printed * for the top level memory context, but only if * talloc_enable_leak_report() or talloc_enable_leak_report_full() has * been called. * * @param[in] ptr The talloc chunk. * * @param[in] f The file handle to print to. * * Example: * @code * unsigned int *a, *b; * a = talloc(NULL, unsigned int); * b = talloc(a, unsigned int); * fprintf(stderr, "Dumping memory tree for a:\n"); * talloc_report_full(a, stderr); * @endcode * * @see talloc_report() */ void talloc_report_full(const void *ptr, FILE *f); /** * @brief Print a summary report of all memory used by ptr. * * This function prints a summary report of all memory used by ptr. One line of * report is printed for each immediate child of ptr, showing the total memory * and number of blocks used by that child. * * You can pass NULL for the pointer, in which case a report is printed * for the top level memory context, but only if talloc_enable_leak_report() * or talloc_enable_leak_report_full() has been called. * * @param[in] ptr The talloc chunk. * * @param[in] f The file handle to print to. * * Example: * @code * unsigned int *a, *b; * a = talloc(NULL, unsigned int); * b = talloc(a, unsigned int); * fprintf(stderr, "Summary of memory tree for a:\n"); * talloc_report(a, stderr); * @endcode * * @see talloc_report_full() */ void talloc_report(const void *ptr, FILE *f); /** * @brief Enable tracking the use of NULL memory contexts. * * This enables tracking of the NULL memory context without enabling leak * reporting on exit. Useful for when you want to do your own leak * reporting call via talloc_report_null_full(); */ void talloc_enable_null_tracking(void); /** * @brief Enable tracking the use of NULL memory contexts. * * This enables tracking of the NULL memory context without enabling leak * reporting on exit. Useful for when you want to do your own leak * reporting call via talloc_report_null_full(); */ void talloc_enable_null_tracking_no_autofree(void); /** * @brief Disable tracking of the NULL memory context. * * This disables tracking of the NULL memory context. */ void talloc_disable_null_tracking(void); /** * @brief Enable leak report when a program exits. * * This enables calling of talloc_report(NULL, stderr) when the program * exits. In Samba4 this is enabled by using the --leak-report command * line option. * * For it to be useful, this function must be called before any other * talloc function as it establishes a "null context" that acts as the * top of the tree. If you don't call this function first then passing * NULL to talloc_report() or talloc_report_full() won't give you the * full tree printout. * * Here is a typical talloc report: * * @code * talloc report on 'null_context' (total 267 bytes in 15 blocks) * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks * iconv(UTF8,CP850) contains 42 bytes in 2 blocks * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks * iconv(CP850,UTF8) contains 42 bytes in 2 blocks * iconv(UTF8,UTF-16LE) contains 45 bytes in 2 blocks * iconv(UTF-16LE,UTF8) contains 45 bytes in 2 blocks * @endcode */ void talloc_enable_leak_report(void); /** * @brief Enable full leak report when a program exits. * * This enables calling of talloc_report_full(NULL, stderr) when the * program exits. In Samba4 this is enabled by using the * --leak-report-full command line option. * * For it to be useful, this function must be called before any other * talloc function as it establishes a "null context" that acts as the * top of the tree. If you don't call this function first then passing * NULL to talloc_report() or talloc_report_full() won't give you the * full tree printout. * * Here is a typical full report: * * @code * full talloc report on 'root' (total 18 bytes in 8 blocks) * p1 contains 18 bytes in 7 blocks (ref 0) * r1 contains 13 bytes in 2 blocks (ref 0) * reference to: p2 * p2 contains 1 bytes in 1 blocks (ref 1) * x3 contains 1 bytes in 1 blocks (ref 0) * x2 contains 1 bytes in 1 blocks (ref 0) * x1 contains 1 bytes in 1 blocks (ref 0) * @endcode */ void talloc_enable_leak_report_full(void); /* @} ******************************************************************/ void talloc_set_abort_fn(void (*abort_fn)(const char *reason)); void talloc_set_log_fn(void (*log_fn)(const char *message)); void talloc_set_log_stderr(void); #if TALLOC_DEPRECATED #define talloc_zero_p(ctx, type) talloc_zero(ctx, type) #define talloc_p(ctx, type) talloc(ctx, type) #define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count) #define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count) #define talloc_destroy(ctx) talloc_free(ctx) #define talloc_append_string(c, s, a) (s?talloc_strdup_append(s,a):talloc_strdup(c, a)) #endif #ifndef TALLOC_MAX_DEPTH #define TALLOC_MAX_DEPTH 10000 #endif #ifdef __cplusplus } /* end of extern "C" */ #endif #endif