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diff --git a/talloc/talloc_guide.txt b/talloc/talloc_guide.txt deleted file mode 100644 index 3201fe6f0..000000000 --- a/talloc/talloc_guide.txt +++ /dev/null @@ -1,694 +0,0 @@ -Using talloc in Samba4 -====================== - -.. contents:: - -Andrew Tridgell -September 2004 - -The most current version of this document is available at - http://samba.org/ftp/unpacked/samba4/source/lib/talloc/talloc_guide.txt - -If you are used to the "old" talloc from Samba3 before 3.0.20 then please read -this carefully, as talloc has changed a lot. With 3.0.20 (or 3.0.14?) the -Samba4 talloc has been ported back to Samba3, so this guide applies to both. - -The new 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 change from Samba3 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:: - - struct foo *X = talloc(mem_ctx, struct foo); - X->name = talloc_strdup(X, "foo"); - -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(). - -If you find this confusing, then I suggest you run the testsuite to -watch talloc in action. You may also like to add your own tests to -testsuite.c to clarify how some particular situation is handled. - - -Performance ------------ - -All the additional features of talloc() over malloc() do come at a -price. We have a simple performance test in Samba4 that measures -talloc() versus malloc() performance, and it seems that talloc() is -about 4% slower than malloc() on my x86 Debian Linux box. For Samba, -the great reduction in code complexity that we get by using talloc -makes this worthwhile, especially as the total overhead of -talloc/malloc in Samba is already quite small. - - -talloc API ----------- - -The following is a complete guide to the talloc API. Read it all at -least twice. - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(type *)talloc(const void *context, type); - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_size(const void *context, size_t size); - -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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(typeof(ptr)) talloc_ptrtype(const void *ctx, ptr); - -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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -int talloc_free(void *ptr); - -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_children(void *ptr); - -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_reference(const void *context, const void *ptr); - -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() - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -int talloc_unlink(const void *context, const void *ptr); - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_set_destructor(const void *ptr, int (*destructor)(void *)); - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -int talloc_increase_ref_count(const void *ptr); - -The talloc_increase_ref_count(ptr) function is exactly equivalent to: - - talloc_reference(NULL, ptr); - -You can use either syntax, depending on which you think is clearer in -your code. - -It returns 0 on success and -1 on failure. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -size_t talloc_reference_count(const void *ptr); - -Return the number of references to the pointer. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_set_name(const void *ptr, const char *fmt, ...); - -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: - talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...)); - -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(). - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_set_name_const(const void *ptr, const char *name); - -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_named(const void *context, size_t size, const char *fmt, ...); - -The talloc_named() function creates a named talloc pointer. It is -equivalent to: - - ptr = talloc_size(context, size); - talloc_set_name(ptr, fmt, ....); - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_named_const(const void *context, size_t size, const char *name); - -This is equivalent to:: - - ptr = talloc_size(context, size); - talloc_set_name_const(ptr, name); - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -const char *talloc_get_name(const void *ptr); - -This returns the current name for the given talloc pointer. See -talloc_set_name() for details. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_init(const char *fmt, ...); - -This function creates a zero length named talloc context as a top -level context. It is equivalent to:: - - talloc_named(NULL, 0, fmt, ...); - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_new(void *ctx); - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(type *)talloc_realloc(const void *context, void *ptr, type, count); - -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:: - - 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); - -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()). - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_realloc_size(const void *context, void *ptr, size_t size); - -the talloc_realloc_size() function is useful when the type is not -known so the typesafe talloc_realloc() cannot be used. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_steal(const void *new_ctx, const void *ptr); - -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. - -talloc_steal (new_ctx, NULL) will return NULL with no sideeffects. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -size_t talloc_total_size(const void *ptr); - -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_blocks(const void *ptr); - -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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -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 *priv), - void *priv); - -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_file(const void *ptr, int depth, int max_depth, FILE *f); - -This provides a more flexible reports than talloc_report(). It -will let you specify the depth and max_depth. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_report(const void *ptr, FILE *f); - -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_full(const void *ptr, FILE *f); - -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_enable_leak_report(void); - -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: - -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 - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_enable_leak_report_full(void); - -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: - -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) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void talloc_enable_null_tracking(void); - -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_disable_null_tracking(void); - -This disables tracking of the NULL memory context. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(type *)talloc_zero(const void *ctx, type); - -The talloc_zero() macro is equivalent to:: - - ptr = talloc(ctx, type); - if (ptr) memset(ptr, 0, sizeof(type)); - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_zero_size(const void *ctx, size_t size) - -The talloc_zero_size() function is useful when you don't have a known type - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_memdup(const void *ctx, const void *p, size_t size); - -The talloc_memdup() function is equivalent to:: - - ptr = talloc_size(ctx, size); - if (ptr) memcpy(ptr, p, size); - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_strdup(const void *ctx, const char *p); - -The talloc_strdup() function is equivalent to:: - - ptr = talloc_size(ctx, strlen(p)+1); - if (ptr) memcpy(ptr, p, strlen(p)+1); - -This functions sets the name of the new pointer to the passed -string. This is equivalent to:: - - talloc_set_name_const(ptr, ptr) - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_strndup(const void *t, const char *p, size_t n); - -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: - talloc_set_name_const(ptr, ptr) - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_append_string(const void *t, char *orig, const char *append); - -The talloc_append_string() function appends the given formatted -string to the given string. - -This function sets the name of the new pointer to the new -string. This is equivalent to:: - - talloc_set_name_const(ptr, ptr) - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_vasprintf(const void *t, const char *fmt, va_list ap); - -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:: - - talloc_set_name_const(ptr, ptr) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_asprintf(const void *t, const char *fmt, ...); - -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:: - - talloc_set_name_const(ptr, ptr) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_asprintf_append(char *s, const char *fmt, ...); - -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:: - - talloc_set_name_const(ptr, ptr) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...); - -The talloc_asprintf_append() function appends the given formatted -string to the end of the currently allocated talloc buffer. -Use this varient when the string in the current talloc buffer has -not been changed. - -This functions sets the name of the new pointer to the new -string. This is equivalent to:: - - talloc_set_name_const(ptr, ptr) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -((type *)talloc_array(const void *ctx, type, uint_t count); - -The talloc_array() macro is equivalent to:: - - (type *)talloc_size(ctx, sizeof(type) * count); - -except that it provides integer overflow protection for the multiply, -returning NULL if the multiply overflows. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_array_size(const void *ctx, size_t size, uint_t count); - -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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(typeof(ptr)) talloc_array_ptrtype(const void *ctx, ptr, uint_t count); - -The talloc_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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_realloc_fn(const void *ctx, void *ptr, size_t 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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_autofree_context(void); - -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_check_name(const void *ptr, const char *name); - -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. - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(type *)talloc_get_type(const void *ptr, type); - -This macro allows you to do type checking on talloc pointers. It is -particularly useful for void* private pointers. It is equivalent to -this:: - - (type *)talloc_check_name(ptr, #type) - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -talloc_set_type(const void *ptr, type); - -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:: - - talloc_set_name_const(ptr, #type) - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -talloc_get_size(const void *ctx); - -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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -void *talloc_find_parent_byname(const void *ctx, const char *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. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -(type *)talloc_find_parent_bytype(ctx, type); - -Like talloc_find_parent_byname() but takes a type, making it typesafe. - |