diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/talloc/talloc.h | 1024 |
1 files changed, 1023 insertions, 1 deletions
diff --git a/lib/talloc/talloc.h b/lib/talloc/talloc.h index 5c8d5c5fe2..4b50ba99c2 100644 --- a/lib/talloc/talloc.h +++ b/lib/talloc/talloc.h @@ -29,7 +29,119 @@ #include <stdio.h> #include <stdarg.h> -/* this is only needed for compatibility with the old talloc */ +/** \mainpage + * + * \section intro_sec Introduction + * + * Talloc is a hierarchical, reference counted memory pool system with + * destructors. Quite a mouthful really, but not too bad once you get used to + * it. + * + * Perhaps the biggest difference from other memory pool systems is that there + * is no distinction between a "talloc context" and a "talloc pointer". Any + * pointer returned from talloc() is itself a valid talloc context. This means + * you can do this: + * + * \code + * struct foo *X = talloc(mem_ctx, struct foo); + * X->name = talloc_strdup(X, "foo"); + * \endcode + * + * and the pointer X->name would be a "child" of the talloc context "X" which + * is itself a child of mem_ctx. So if you do talloc_free(mem_ctx) then it is + * all destroyed, whereas if you do talloc_free(X) then just X and X->name are + * destroyed, and if you do talloc_free(X->name) then just the name element of + * X is destroyed. + * + * If you think about this, then what this effectively gives you is an n-ary + * tree, where you can free any part of the tree with talloc_free(). + * + * \section named_blocks Named blocks + * + * Every talloc chunk has a name that can be used as a dynamic type-checking + * system. If for some reason like a callback function you had to cast a + * "struct foo *" to a "void *" variable, later you can safely reassign the + * "void *" pointer to a "struct foo *" by using the talloc_get_type() or + * talloc_get_type_abort() macros. + * + * \code + * struct foo *X = talloc_get_type_abort(ptr, struct foo); + * \endcode + * + * This will abort if "ptr" does not contain a pointer that has been created + * with talloc(mem_ctx, struct foo). + * + * \section multi_threading Multi-Threading + * + * talloc itself does not deal with threads. It is thread-safe (assuming the + * underlying "malloc" is), as long as each thread uses different memory + * contexts. + * + * If two threads uses the same context then they need to synchronize in order + * to be safe. In particular: + * + * + * - when using talloc_enable_leak_report(), giving directly NULL as a + * parent context implicitly refers to a hidden "null context" global + * variable, so this should not be used in a multi-threaded environment + * without proper synchronization + * - the context returned by talloc_autofree_context() is also global so + * shouldn't be used by several threads simultaneously without + * synchronization. + */ + +/** \defgroup talloc_basic Basic Talloc Routines + * + * This module contains the basic talloc routines that are used in everyday + * programming. + */ + +/** \defgroup talloc_ref Talloc References + * + * This module contains the definitions around talloc references + */ + +/** \defgroup talloc_array Array routines + * + * Talloc contains some handy helpers for handling Arrays conveniently + */ + +/** \defgroup talloc_string String handling routines + * + * Talloc contains some handy string handling functions + */ + +/** \defgroup talloc_debug Debugging support routines + * + * To aid memory debugging, talloc contains routines to inspect the currently + * allocated memory hierarchy. + */ + +/** + * \typedef TALLOC_CTX + * \brief Define a talloc parent type + * \ingroup talloc_basic + * + * 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; /* @@ -58,6 +170,62 @@ typedef void TALLOC_CTX; #endif #endif +/** + * \def talloc_set_destructor + * \brief Assign a function to be called when a chunk is freed + * \param ptr The talloc chunk to add a destructor to + * \param function The destructor function to be called + * \ingroup talloc_basic + * + * 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. + */ + +/** + * \def talloc_steal(ctx, ptr) + * \brief Change a talloc chunk's parent + * \param ctx The new parent context + * \param ptr The talloc chunk to move + * \return ptr + * \ingroup talloc_basic + * + * 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. + * + * The talloc_steal() function 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. + * + * To make the changed hierarchy less error-prone, you might consider to use + * talloc_move(). + * + * talloc_steal (ctx, NULL) will return NULL with no sideeffects. + */ + /* try to make talloc_set_destructor() and talloc_steal() type safe, if we have a recent gcc */ #if (__GNUC__ >= 3) @@ -77,34 +245,359 @@ typedef void TALLOC_CTX; #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr)) #endif +/** + * \def talloc_reference(ctx, ptr) + * \brief Create an additional talloc parent to a pointer + * \param ctx The additional parent + * \param ptr The pointer you want to create an additional parent for + * \return ptr + * \ingroup talloc_ref + * + * The talloc_reference() function makes "context" an additional parent of + * "ptr". + * + * The return value of talloc_reference() is always the original pointer + * "ptr", unless talloc ran out of memory in creating the reference in which + * case it will return NULL (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() + */ #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr)) + + +/** + * \def talloc_move(ctx, ptr) + * \brief Change a talloc chunk's parent + * \param ctx The new parent context + * \param ptr Pointer to the talloc chunk to move + * \return ptr + * \ingroup talloc_basic + * + * talloc_move() 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 + */ #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr)) /* useful macros for creating type checked pointers */ + +/** + * \def talloc(ctx, type) + * \brief Main entry point to allocate structures + * \param ctx The talloc context to hang the result off + * \param type The type that we want to allocate + * \return Pointer to a piece of memory, properly cast to "type *" + * \ingroup talloc_basic + * + * 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. + * + * The context argument to talloc() can be NULL, in which case a new top + * level context is created. + */ #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type) + +/** + * \def talloc_size(ctx, size) + * \brief Untyped allocation + * \param ctx The talloc context to hang the result off + * \param size Number of char's that you want to allocate + * \return The allocated memory chunk + * \ingroup talloc_basic + * + * The function talloc_size() 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. + */ #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__) + +/** + * \def talloc_ptrtype(ctx, ptr) + * \brief Allocate into a typed pointer + * \param ctx The talloc context to hang the result off + * \param ptr The pointer you want to assign the result to + * \result The allocated memory chunk, properly cast + * \ingroup talloc_basic + * + * 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. + */ #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr))) +/** + * \def talloc_new(ctx) + * \brief Allocate a new 0-sized talloc chunk + * \param ctx The talloc parent context + * \return A new talloc chunk + * \ingroup talloc_basic + * + * This is a utility macro that creates a new memory context hanging off an + * exiting 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. + */ #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__) +/** + * \def talloc_zero(ctx, type) + * \brief Allocate a 0-initizialized structure + * \param ctx The talloc context to hang the result off + * \param type The type that we want to allocate + * \return Pointer to a piece of memory, properly cast to "type *" + * \ingroup talloc_basic + * + * The talloc_zero() macro is equivalent to: + * + * \code + * ptr = talloc(ctx, type); + * if (ptr) memset(ptr, 0, sizeof(type)); + * \endcode + */ #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type) + +/** + * \def talloc_zero_size(ctx, size) + * \brief Untyped, 0-initialized allocation + * \param ctx The talloc context to hang the result off + * \param size Number of char's that you want to allocate + * \return The allocated memory chunk + * \ingroup talloc_basic + * + * The talloc_zero_size() macro is equivalent to: + * + * \code + * ptr = talloc_size(ctx, size); + * if (ptr) memset(ptr, 0, size); + * \endcode + */ + #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__) #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type) + +/** + * \def talloc_array(ctx, type, count) + * \brief Allocate an array + * \param ctx The talloc context to hang the result off + * \param type The type that we want to allocate + * \param count The number of "type" elements you want to allocate + * \return The allocated result, properly cast to "type *" + * \ingroup talloc_array + * + * The talloc_array() 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. + */ #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type) + +/** + * \def talloc_array_size(ctx, size, count) + * \brief Allocate an array + * \param ctx The talloc context to hang the result off + * \param size The size of an array element + * \param count The number of "type" elements you want to allocate + * \return The allocated result, properly cast to "type *" + * \ingroup talloc_array + * + * The talloc_array_size() function is useful when the type is not + * known. It operates in the same way as talloc_array(), but takes a size + * instead of a type. + */ #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__) + +/** + * \def talloc_array_ptrtype(ctx, ptr, count) + * \brief Allocate an array into a typed pointer + * \param ctx The talloc context to hang the result off + * \param ptr The pointer you want to assign the result to + * \param count The number of elements you want to allocate + * \result The allocated memory chunk, properly cast + * \ingroup talloc_array + * + * The talloc_array_ptrtype() 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. + */ #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count) + +/** + * \def talloc_array_length(ctx) + * \brief Return the number of elements in a talloc'ed array + * \param ctx The talloc'ed array + * \return The number of elements in ctx + * \ingroup talloc_array + * + * A talloc chunk carries its own size, so for talloc'ed arrays it is not + * necessary to store the number of elements explicitly. + */ #define talloc_array_length(ctx) ((ctx) ? talloc_get_size(ctx)/sizeof(*ctx) : 0) +/** + * \def talloc_realloc(ctx, p, type, count) + * \brief Change the size of a talloc array + * \param ctx The parent context used if "p" is NULL + * \param p The chunk to be resized + * \param type The type of the array element inside p + * \param count The intended number of array elements + * \return The new array + * \ingroup talloc_array + * + * The talloc_realloc() 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(context, NULL, type, 1) ==> talloc(context, type); + * talloc_realloc(context, NULL, type, N) ==> talloc_array(context, type, N); + * talloc_realloc(context, ptr, type, 0) ==> talloc_free(ptr); + * \endcode + * + * The "context" argument is only used if "ptr" is NULL, otherwise it is + * ignored. + * + * talloc_realloc() returns the new pointer, or NULL on failure. The call + * will fail either due to a lack of memory, or because the pointer has + * more than one parent (see talloc_reference()). + */ #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type) + +/** + * \def talloc_realloc_size(ctx, ptr, size) + * \brief Untyped realloc + * \param ctx The parent context used if "ptr" is NULL + * \param ptr The chunk to be resized + * \param size The new chunk size + * \return The new chunk + * \ingroup talloc_array + * + * The talloc_realloc_size() function is useful when the type is not known so + * the typesafe talloc_realloc() cannot be used. + */ #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__) +/** + * \def talloc_memdup(t, p, size) + * \brief Duplicate a memory area into a talloc chunk + * \param t The talloc context to hang the result off + * \param p The memory chunk you want to duplicate + * \param size Number of char's that you want copy + * \return The allocated memory chunk + * \ingroup talloc_basic + * + * The talloc_memdup() function is equivalent to:: + * + * \code + * ptr = talloc_size(ctx, size); + * if (ptr) memcpy(ptr, p, size); + * \endcode + */ #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__) +/** + * \def talloc_set_type(ptr, type) + * \brief Assign a type to a talloc chunk + * \param ptr The talloc chunk to assign the type to + * \param type The type to assign + * \ingroup talloc_basic + * + * 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 + */ #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type) + +/** + * \def talloc_get_type(ptr, type) + * \brief Get a typed pointer out of a talloc pointer + * \param ptr The talloc pointer to check + * \param type The type to check against + * \return ptr, properly cast, or NULL + * \ingroup talloc_basic + * + * 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 + */ + #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type) + +/** + * \def talloc_get_type_abort(ptr, type) + * \brief Helper macro to safely turn a void * into a typed pointer + * \param ptr The void * to convert + * \param type The type that this chunk contains + * \return Same value as ptr, type-checked and properly cast + * \ingroup talloc_basic + * + * This macro is used together with talloc(mem_ctx, struct foo). If you had to + * assing the talloc chunk pointer to some void * variable, + * talloc_get_type_abort() is the recommended way to get the convert the void + * pointer back to a typed pointer. + */ #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__) +/** + * \def talloc_find_parent_bytype(ptr, type) + * \brief Find a parent context by type + * \param ptr The talloc chunk to start from + * \param type The type of the parent to look for + * \ingroup talloc_basic + * + * 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. + */ #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type) #if TALLOC_DEPRECATED @@ -122,67 +615,596 @@ typedef void TALLOC_CTX; void *_talloc(const void *context, size_t size); void *talloc_pool(const void *context, size_t size); void _talloc_set_destructor(const void *ptr, int (*destructor)(void *)); + +/** + * \brief Increase the reference count of a talloc chunk + * \param ptr + * \return success? + * \ingroup talloc_ref + * + * 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. + * + * It returns 0 on success and -1 on failure. + */ int talloc_increase_ref_count(const void *ptr); + +/** + * \brief Return the number of references to a talloc chunk + * \param ptr The chunk you are interested in + * \return Number of refs + * \ingroup talloc_ref + */ size_t talloc_reference_count(const void *ptr); void *_talloc_reference(const void *context, const void *ptr); + +/** + * \brief Remove a specific parent from a talloc chunk + * \param context The talloc parent to remove + * \param ptr The talloc ptr you want to remove the parent from + * \ingroup talloc_ref + * + * The talloc_unlink() 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. + * + * Note that 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. + * + * 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. + */ int talloc_unlink(const void *context, void *ptr); + +/** + * \brief Assign a name to a talloc chunk + * \param ptr The talloc chunk to assign a name to + * \param fmt Format string for the name + * \param ... printf-style additional arguments + * \return The assigned name + * \ingroup talloc_basic + * + * 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 + * + * Note that 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); + +/** + * \brief Assign a name to a talloc chunk + * \param ptr The talloc chunk to assign a name to + * \param name Format string for the name + * \ingroup talloc_basic + * + * The function talloc_set_name_const() 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(). + */ void talloc_set_name_const(const void *ptr, const char *name); + +/** + * \brief Create a named talloc chunk + * \param context The talloc context to hang the result off + * \param size Number of char's that you want to allocate + * \param fmt Format string for the name + * \param ... printf-style additional arguments + * \return The allocated memory chunk + * \ingroup talloc_basic + * + * 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 + * + */ 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 + * \param context The parent context + * \param size The number of char's that we want to allocate + * \param name The name the talloc block has + * \return The allocated chunk + * \ingroup talloc_basic + * + * This is equivalent to: + * + * \code + * ptr = talloc_size(context, size); + * talloc_set_name_const(ptr, name); + * \endcode + */ void *talloc_named_const(const void *context, size_t size, const char *name); + +/** + * \brief Return the name of a talloc chunk + * \param ptr The talloc chunk + * \return The name + * \ingroup talloc_basic + * + * This returns the current name for the given talloc pointer. See + * talloc_set_name() for details. + */ const char *talloc_get_name(const void *ptr); + +/** + * \brief Verify that a talloc chunk carries a specified name + * \param ptr The talloc chunk to check + * \param name The name to check agains + * \ingroup talloc_basic + * + * This function checks if a pointer has the specified name. If it does + * then the pointer is returned. It it doesn't then NULL is returned. + */ void *talloc_check_name(const void *ptr, const char *name); + void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location); void *talloc_parent(const void *ptr); const char *talloc_parent_name(const void *ptr); + +/** + * \brief Create a new top level talloc context + * \param fmt Format string for the name + * \param ... printf-style additional arguments + * \return The allocated memory chunk + * \ingroup talloc_basic + * + * 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 + */ void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2); + +/** + * \brief Free a chunk of talloc memory + * \param ptr The chunk to be freed + * \return success? + * \ingroup talloc_basic + * + * 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. The only 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. + * + * 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. + */ int talloc_free(void *ptr); + +/** + * \brief Free a talloc chunk's children + * \param ptr The chunk that you want to free the children of + * \return success? + * \ingroup talloc_basic + * + * The talloc_free_children() walks along the list of all children of a talloc + * context and talloc_free()s only the children, not the context itself. + */ void talloc_free_children(void *ptr); void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name); void *_talloc_steal(const void *new_ctx, const void *ptr); void *_talloc_move(const void *new_ctx, const void *pptr); + +/** + * \brief Return the total size of a talloc chunk including its children + * \param ptr The talloc chunk + * \return The total size + * \ingroup talloc_basic + * + * The talloc_total_size() 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. + */ size_t talloc_total_size(const void *ptr); + +/** + * \brief Return the number of talloc chunks hanging off a chunk + * \param ptr The talloc chunk + * \return The total size + * \ingroup talloc_basic + * + * 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. + */ size_t talloc_total_blocks(const void *ptr); + +/** + * \brief Walk a complete talloc hierarchy + * \param ptr The talloc chunk + * \param depth Internal parameter to control recursion. Call with 0. + * \param max_depth Maximum recursion level. + * \param callback Function to be called on every chunk + * \param private_data Private pointer passed to callback + * \ingroup talloc_debug + * + * 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. + */ 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 + * \param ptr The talloc chunk + * \param depth Internal parameter to control recursion. Call with 0. + * \param max_depth Maximum recursion level. + * \param f The file handle to print to + * \ingroup talloc_debug + * + * This provides a more flexible reports than talloc_report(). It + * will let you specify the depth and max_depth. + */ 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 + * \param ptr The talloc chunk + * \param f The file handle to print to + * \ingroup talloc_debug + * + * 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. + */ void talloc_report_full(const void *ptr, FILE *f); + +/** + * \brief Print a summary report of all memory used by ptr + * \param ptr The talloc chunk + * \param f The file handle to print to + * \ingroup talloc_debug + * + * The talloc_report() 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. + */ void talloc_report(const void *ptr, FILE *f); + +/** + * \brief Enable tracking the use of NULL memory contexts + * \ingroup talloc_debug + * + * 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 Disable tracking of the NULL memory context + * \ingroup talloc_debug + * + * This disables tracking of the NULL memory context. + */ + void talloc_disable_null_tracking(void); + +/** + * \brief Enable calling of talloc_report(NULL, stderr) when a program exits + * \ingroup talloc_debug + * + * 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: + * +\verbatim +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 +\endverbatim + */ void talloc_enable_leak_report(void); + +/** + * \brief Enable calling of talloc_report(NULL, stderr) when a program exits + * \ingroup talloc_debug + * + * 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: +\verbatim +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) +\endverbatim +*/ void talloc_enable_leak_report_full(void); void *_talloc_zero(const void *ctx, size_t size, const char *name); void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name); void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name); void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name); void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name); + +/** + * \brief Provide a function version of talloc_realloc_size + * \param context The parent context used if "ptr" is NULL + * \param ptr The chunk to be resized + * \param size The new chunk size + * \return The new chunk + * \ingroup talloc_array + * + * 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. +*/ void *talloc_realloc_fn(const void *context, void *ptr, size_t size); + +/** + * \brief Provide a talloc context that is freed at program exit + * \return A talloc context + * \ingroup talloc_basic + * + * 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. + */ void *talloc_autofree_context(void); + +/** + * \brief Get the size of a talloc chunk + * \param ctx The talloc chunk + * \return The size + * \ingroup talloc_basic + * + * 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. + */ size_t talloc_get_size(const void *ctx); + +/** + * \brief Find a parent context by name + * \param ctx The talloc chunk to start from + * \param name The name of the parent we look for + * \ingroup talloc_basic + * + * 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. + */ void *talloc_find_parent_byname(const void *ctx, const char *name); void talloc_show_parents(const void *context, FILE *file); int talloc_is_parent(const void *context, const void *ptr); +/** + * \brief Duplicate a string into a talloc chunk + * \param t The talloc context to hang the result off + * \param p The string you want to duplicate + * \return The duplicated string + * \ingroup talloc_string + * + * The talloc_strdup() 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 + */ char *talloc_strdup(const void *t, const char *p); char *talloc_strdup_append(char *s, const char *a); char *talloc_strdup_append_buffer(char *s, const char *a); +/** + * \brief Duplicate a length-limited string into a talloc chunk + * \param t The talloc context to hang the result off + * \param p The string you want to duplicate + * \param n The maximum string length to duplicate + * \return The duplicated string + * \ingroup talloc_string + * + * The talloc_strndup() function is the talloc equivalent of the C + * library function strndup() + * + * 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 + */ char *talloc_strndup(const void *t, const char *p, size_t n); char *talloc_strndup_append(char *s, const char *a, size_t n); char *talloc_strndup_append_buffer(char *s, const char *a, size_t n); +/** + * \brief Format a string given a va_list + * \param t The talloc context to hang the result off + * \param fmt The format string + * \param ap The parameters used to fill fmt + * \return The formatted string + * \ingroup talloc_string + * + * The talloc_vasprintf() function is the talloc equivalent of the C + * library function vasprintf() + * + * 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 + */ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0); +/** + * \brief Format a string + * \param t The talloc context to hang the result off + * \param fmt The format string + * \param ... The parameters used to fill fmt + * \return The formatted string + * \ingroup talloc_string + * + * The talloc_asprintf() function is the talloc equivalent of the C + * library function asprintf() + * + * 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 + */ char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); + +/** + * \brief Append a formatted string to another string + * \param s The string to append to + * \param fmt The format string + * \param ... The parameters used to fill fmt + * \return The formatted string + * \ingroup talloc_string + * + * The talloc_asprintf_append() 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 + */ char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); + +/** + * \brief Append a formatted string to another string + * \param s The string to append to + * \param fmt The format string + * \param ... The parameters used to fill fmt + * \return The formatted string + * \ingroup talloc_string + * + * The talloc_asprintf_append() function appends the given formatted string to + * the end of the currently allocated talloc buffer. This routine should be + * used if you create a large string step by step. talloc_asprintf() or + * talloc_asprintf_append() call strlen() at every + * step. talloc_asprintf_append_buffer() uses the existing buffer size of the + * talloc chunk to calculate where to append the string. + * + * 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 + */ char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3); void talloc_set_abort_fn(void (*abort_fn)(const char *reason)); |