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diff --git a/talloc/talloc.3.xml b/talloc/talloc.3.xml deleted file mode 100644 index 67de15bfc..000000000 --- a/talloc/talloc.3.xml +++ /dev/null @@ -1,738 +0,0 @@ -<?xml version="1.0"?> -<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> -<refentry> - <refmeta> - <refentrytitle>talloc</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - <refnamediv> - <refname>talloc</refname> -<refpurpose>hierarchical reference counted memory pool system with destructors</refpurpose> - </refnamediv> - <refsynopsisdiv> -<synopsis>#include <talloc/talloc.h></synopsis> - </refsynopsisdiv> - <refsect1><title>DESCRIPTION</title> - <para> - If you are used to talloc from Samba3 then please read this - carefully, as talloc has changed a lot. - </para> - <para> - 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. - </para> - <para> - 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: - </para> - <programlisting> - struct foo *X = talloc(mem_ctx, struct foo); - X->name = talloc_strdup(X, "foo"); - </programlisting> - <para> - and the pointer <literal role="code">X->name</literal> - would be a "child" of the talloc context <literal - role="code">X</literal> which is itself a child of - <literal role="code">mem_ctx</literal>. So if you do - <literal role="code">talloc_free(mem_ctx)</literal> then - it is all destroyed, whereas if you do <literal - role="code">talloc_free(X)</literal> then just <literal - role="code">X</literal> and <literal - role="code">X->name</literal> are destroyed, and if - you do <literal - role="code">talloc_free(X->name)</literal> then just - the name element of <literal role="code">X</literal> is - destroyed. - </para> - <para> - 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(). - </para> - <para> - If you find this confusing, then I suggest you run the <literal - role="code">testsuite</literal> program to watch talloc - in action. You may also like to add your own tests to <literal - role="code">testsuite.c</literal> to clarify how some - particular situation is handled. - </para> - </refsect1> - <refsect1><title>TALLOC API</title> - <para> - The following is a complete guide to the talloc API. Read it all at - least twice. - </para> - <refsect2><title>(type *)talloc(const void *ctx, type);</title> - <para> - The talloc() macro is the core of the talloc library. It takes a - memory <emphasis role="italic">ctx</emphasis> and a <emphasis - role="italic">type</emphasis>, and returns a pointer to a new - area of memory of the given <emphasis - role="italic">type</emphasis>. - </para> - <para> - The returned pointer is itself a talloc context, so you can use - it as the <emphasis role="italic">ctx</emphasis> argument to more - calls to talloc() if you wish. - </para> - <para> - The returned pointer is a "child" of the supplied context. This - means that if you talloc_free() the <emphasis - role="italic">ctx</emphasis> then the new child disappears as - well. Alternatively you can free just the child. - </para> - <para> - The <emphasis role="italic">ctx</emphasis> argument to talloc() - can be NULL, in which case a new top level context is created. - </para> - </refsect2> - <refsect2><title>void *talloc_size(const void *ctx, size_t size);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>(typeof(ptr)) talloc_ptrtype(const void *ctx, ptr);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>int talloc_free(void *ptr);</title> - <para> - 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(). - </para> - <para> - 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 <emphasis - role="italic">ptr</emphasis> had a destructor attached to it and - the destructor returned -1. See <link - linkend="talloc_set_destructor"><quote>talloc_set_destructor()</quote></link> - for details on destructors. - </para> - <para> - 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 <link - linkend="talloc_reference"><quote>talloc_reference()</quote></link> - for details on establishing additional parents. - </para> - <para> - For more control on which parent is removed, see <link - linkend="talloc_unlink"><quote>talloc_unlink()</quote></link>. - </para> - <para> - talloc_free() operates recursively on its children. - </para> - </refsect2> - <refsect2 id="talloc_reference"><title>void *talloc_reference(const void *ctx, const void *ptr);</title> - <para> - The talloc_reference() function makes <emphasis - role="italic">ctx</emphasis> an additional parent of <emphasis - role="italic">ptr</emphasis>. - </para> - <para> - The return value of talloc_reference() is always the original - pointer <emphasis role="italic">ptr</emphasis>, 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). - </para> - <para> - If <emphasis role="italic">ptr</emphasis> is NULL, then the - function is a no-op, and simply returns NULL. - </para> - <para> - After creating a reference you can free it in one of the - following ways: - </para> - <para> - <itemizedlist> - <listitem> - <para> - 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. - </para> - </listitem> - <listitem> - <para> - 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. - </para> - </listitem> - </itemizedlist> - </para> - <para> - For more control on which parent to remove, see <link - linkend="talloc_unlink"><quote>talloc_unlink()</quote></link>. - </para> - </refsect2> - <refsect2 id="talloc_unlink"><title>int talloc_unlink(const void *ctx, const void *ptr);</title> - <para> - The talloc_unlink() function removes a specific parent from - <emphasis role="italic">ptr</emphasis>. The <emphasis - role="italic">ctx</emphasis> passed must either be a context used - in talloc_reference() with this pointer, or must be a direct - parent of ptr. - </para> - <para> - Note that if the parent has already been removed using - talloc_free() then this function will fail and will return -1. - Likewise, if <emphasis role="italic">ptr</emphasis> is NULL, then - the function will make no modifications and return -1. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2 id="talloc_set_destructor"><title>void talloc_set_destructor(const void *ptr, int (*destructor)(void *));</title> - <para> - The function talloc_set_destructor() sets the <emphasis - role="italic">destructor</emphasis> for the pointer <emphasis - role="italic">ptr</emphasis>. A <emphasis - role="italic">destructor</emphasis> is a function that is called - when the memory used by a pointer is about to be released. The - destructor receives <emphasis role="italic">ptr</emphasis> as an - argument, and should return 0 for success and -1 for failure. - </para> - <para> - The <emphasis role="italic">destructor</emphasis> 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. - </para> - <para> - 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. - </para> - <para> - To remove a destructor call talloc_set_destructor() with NULL for - the destructor. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2><title>int talloc_increase_ref_count(const void *<emphasis role="italic">ptr</emphasis>);</title> - <para> - The talloc_increase_ref_count(<emphasis - role="italic">ptr</emphasis>) function is exactly equivalent to: - </para> - <programlisting>talloc_reference(NULL, ptr);</programlisting> - <para> - You can use either syntax, depending on which you think is - clearer in your code. - </para> - <para> - It returns 0 on success and -1 on failure. - </para> - </refsect2> - <refsect2><title>size_t talloc_reference_count(const void *<emphasis role="italic">ptr</emphasis>);</title> - <para> - Return the number of references to the pointer. - </para> - </refsect2> - <refsect2 id="talloc_set_name"><title>void talloc_set_name(const void *ptr, const char *fmt, ...);</title> - <para> - 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. - </para> - <para> - The main use for names on pointer is for "talloc reports". See - <link - linkend="talloc_report"><quote>talloc_report_depth_cb()</quote></link>, - <link - linkend="talloc_report"><quote>talloc_report_depth_file()</quote></link>, - <link - linkend="talloc_report"><quote>talloc_report()</quote></link> - <link - linkend="talloc_report"><quote>talloc_report()</quote></link> - and <link - linkend="talloc_report_full"><quote>talloc_report_full()</quote></link> - for details. Also see <link - linkend="talloc_enable_leak_report"><quote>talloc_enable_leak_report()</quote></link> - and <link - linkend="talloc_enable_leak_report_full"><quote>talloc_enable_leak_report_full()</quote></link>. - </para> - <para> - The talloc_set_name() function allocates memory as a child of the - pointer. It is logically equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));</programlisting> - <para> - 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(). - </para> - </refsect2> - <refsect2><title>void talloc_set_name_const(const void *<emphasis role="italic">ptr</emphasis>, const char *<emphasis role="italic">name</emphasis>);</title> - <para> - 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(). - </para> - <para> - 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 <emphasis - role="italic">name</emphasis> pointer to memory that will - disappear before <emphasis role="italic">ptr</emphasis> is freed - with talloc_free(). - </para> - </refsect2> - <refsect2><title>void *talloc_named(const void *<emphasis role="italic">ctx</emphasis>, size_t <emphasis role="italic">size</emphasis>, const char *<emphasis role="italic">fmt</emphasis>, ...);</title> - <para> - The talloc_named() function creates a named talloc pointer. It - is equivalent to: - </para> - <programlisting>ptr = talloc_size(ctx, size); -talloc_set_name(ptr, fmt, ....);</programlisting> - </refsect2> - <refsect2><title>void *talloc_named_const(const void *<emphasis role="italic">ctx</emphasis>, size_t <emphasis role="italic">size</emphasis>, const char *<emphasis role="italic">name</emphasis>);</title> - <para> - This is equivalent to: - </para> - <programlisting>ptr = talloc_size(ctx, size); -talloc_set_name_const(ptr, name);</programlisting> - </refsect2> - <refsect2><title>const char *talloc_get_name(const void *<emphasis role="italic">ptr</emphasis>);</title> - <para> - This returns the current name for the given talloc pointer, - <emphasis role="italic">ptr</emphasis>. See <link - linkend="talloc_set_name"><quote>talloc_set_name()</quote></link> - for details. - </para> - </refsect2> - <refsect2><title>void *talloc_init(const char *<emphasis role="italic">fmt</emphasis>, ...);</title> - <para> - This function creates a zero length named talloc context as a top - level context. It is equivalent to: - </para> - <programlisting>talloc_named(NULL, 0, fmt, ...);</programlisting> - </refsect2> - <refsect2><title>void *talloc_new(void *<emphasis role="italic">ctx</emphasis>);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>(<emphasis role="italic">type</emphasis> *)talloc_realloc(const void *<emphasis role="italic">ctx</emphasis>, void *<emphasis role="italic">ptr</emphasis>, <emphasis role="italic">type</emphasis>, <emphasis role="italic">count</emphasis>);</title> - <para> - The talloc_realloc() macro changes the size of a talloc pointer. - It has the following equivalences: - </para> - <programlisting>talloc_realloc(ctx, NULL, type, 1) ==> talloc(ctx, type); -talloc_realloc(ctx, ptr, type, 0) ==> talloc_free(ptr);</programlisting> - <para> - The <emphasis role="italic">ctx</emphasis> argument is only used - if <emphasis role="italic">ptr</emphasis> is not NULL, otherwise - it is ignored. - </para> - <para> - 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 <link - linkend="talloc_reference"><quote>talloc_reference()</quote></link>). - </para> - </refsect2> - <refsect2><title>void *talloc_realloc_size(const void *ctx, void *ptr, size_t size);</title> - <para> - the talloc_realloc_size() function is useful when the type is not - known so the type-safe talloc_realloc() cannot be used. - </para> - </refsect2> - <refsect2><title>TYPE *talloc_steal(const void *<emphasis role="italic">new_ctx</emphasis>, const TYPE *<emphasis role="italic">ptr</emphasis>);</title> - <para> - 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. - </para> - <para> - The talloc_steal() function returns the pointer that you pass it. - It does not have any failure modes. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2><title>TYPE *talloc_move(const void *<emphasis role="italic">new_ctx</emphasis>, TYPE **<emphasis role="italic">ptr</emphasis>);</title> - <para> - The talloc_move() function is a wrapper around - talloc_steal() which zeros the source pointer after the - move. This avoids a potential source of bugs where a - programmer leaves a pointer in two structures, and uses the - pointer from the old structure after it has been moved to a - new one. - </para> - </refsect2> - <refsect2><title>size_t talloc_total_size(const void *<emphasis role="italic">ptr</emphasis>);</title> - <para> - The talloc_total_size() function returns the total size in bytes - used by this pointer and all child pointers. Mostly useful for - debugging. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2><title>size_t talloc_total_blocks(const void *<emphasis role="italic">ptr</emphasis>);</title> - <para> - The talloc_total_blocks() function returns the total memory block - count used by this pointer and all child pointers. Mostly useful - for debugging. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2 id="talloc_report"><title>void talloc_report(const void *ptr, FILE *f);</title> - <para> - The talloc_report() function prints a summary report of all - memory used by <emphasis role="italic">ptr</emphasis>. One line - of report is printed for each immediate child of ptr, showing the - total memory and number of blocks used by that child. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2 id="talloc_report_full"><title>void talloc_report_full(const void *<emphasis role="italic">ptr</emphasis>, FILE *<emphasis role="italic">f</emphasis>);</title> - <para> - This provides a more detailed report than talloc_report(). It - will recursively print the entire tree of memory referenced by - the pointer. References in the tree are shown by giving the name - of the pointer that is referenced. - </para> - <para> - 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. - </para> - </refsect2> - <refsect2 id="talloc_report_depth_cb"> - <funcsynopsis><funcprototype> - <funcdef>void <function>talloc_report_depth_cb</function></funcdef> - <paramdef><parameter>const void *ptr</parameter></paramdef> - <paramdef><parameter>int depth</parameter></paramdef> - <paramdef><parameter>int max_depth</parameter></paramdef> - <paramdef><parameter>void (*callback)(const void *ptr, int depth, int max_depth, int is_ref, void *priv)</parameter></paramdef> - <paramdef><parameter>void *priv</parameter></paramdef> - </funcprototype></funcsynopsis> - <para> - 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 - <emphasis role="italic">is_ref = 1</emphasis> and the pointer that is referenced. - </para> - <para> - 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. - </para> - <para> - The recursion is stopped when depth >= max_depth. - max_depth = -1 means only stop at leaf nodes. - </para> - </refsect2> - <refsect2 id="talloc_report_depth_file"> - <funcsynopsis><funcprototype> - <funcdef>void <function>talloc_report_depth_file</function></funcdef> - <paramdef><parameter>const void *ptr</parameter></paramdef> - <paramdef><parameter>int depth</parameter></paramdef> - <paramdef><parameter>int max_depth</parameter></paramdef> - <paramdef><parameter>FILE *f</parameter></paramdef> - </funcprototype></funcsynopsis> - <para> - This provides a more flexible reports than talloc_report(). It - will let you specify the depth and max_depth. - </para> - </refsect2> - <refsect2 id="talloc_enable_leak_report"><title>void talloc_enable_leak_report(void);</title> - <para> - 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. - </para> - <para> - 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. - </para> - <para> - Here is a typical talloc report: - </para> - <screen format="linespecific">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 - </screen> - </refsect2> - <refsect2 id="talloc_enable_leak_report_full"><title>void talloc_enable_leak_report_full(void);</title> - <para> - 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. - </para> - <para> - 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. - </para> - <para> - Here is a typical full report: - </para> - <screen format="linespecific">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) - </screen> - </refsect2> - <refsect2><title>(<emphasis role="italic">type</emphasis> *)talloc_zero(const void *<emphasis role="italic">ctx</emphasis>, <emphasis role="italic">type</emphasis>);</title> - <para> - The talloc_zero() macro is equivalent to: - </para> - <programlisting>ptr = talloc(ctx, type); -if (ptr) memset(ptr, 0, sizeof(type));</programlisting> - </refsect2> - <refsect2><title>void *talloc_zero_size(const void *<emphasis role="italic">ctx</emphasis>, size_t <emphasis role="italic">size</emphasis>)</title> - <para> - The talloc_zero_size() function is useful when you don't have a - known type. - </para> - </refsect2> - <refsect2><title>void *talloc_memdup(const void *<emphasis role="italic">ctx</emphasis>, const void *<emphasis role="italic">p</emphasis>, size_t size);</title> - <para> - The talloc_memdup() function is equivalent to: - </para> - <programlisting>ptr = talloc_size(ctx, size); -if (ptr) memcpy(ptr, p, size);</programlisting> - </refsect2> - <refsect2><title>char *talloc_strdup(const void *<emphasis role="italic">ctx</emphasis>, const char *<emphasis role="italic">p</emphasis>);</title> - <para> - The talloc_strdup() function is equivalent to: - </para> - <programlisting>ptr = talloc_size(ctx, strlen(p)+1); -if (ptr) memcpy(ptr, p, strlen(p)+1);</programlisting> - <para> - This function sets the name of the new pointer to the passed - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>char *talloc_strndup(const void *<emphasis role="italic">t</emphasis>, const char *<emphasis role="italic">p</emphasis>, size_t <emphasis role="italic">n</emphasis>);</title> - <para> - The talloc_strndup() function is the talloc equivalent of the C - library function strndup(3). - </para> - <para> - This function sets the name of the new pointer to the passed - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>char *talloc_append_string(const void *<emphasis role="italic">t</emphasis>, char *<emphasis role="italic">orig</emphasis>, const char *<emphasis role="italic">append</emphasis>);</title> - <para> - The talloc_append_string() function appends the given formatted - string to the given string. - </para> - <para> - This function sets the name of the new pointer to the new - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>char *talloc_vasprintf(const void *<emphasis role="italic">t</emphasis>, const char *<emphasis role="italic">fmt</emphasis>, va_list <emphasis role="italic">ap</emphasis>);</title> - <para> - The talloc_vasprintf() function is the talloc equivalent of the C - library function vasprintf(3). - </para> - <para> - This function sets the name of the new pointer to the new - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>char *talloc_asprintf(const void *<emphasis role="italic">t</emphasis>, const char *<emphasis role="italic">fmt</emphasis>, ...);</title> - <para> - The talloc_asprintf() function is the talloc equivalent of the C - library function asprintf(3). - </para> - <para> - This function sets the name of the new pointer to the passed - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>char *talloc_asprintf_append(char *s, const char *fmt, ...);</title> - <para> - The talloc_asprintf_append() function appends the given formatted - string to the given string. - </para> - <para> - This function sets the name of the new pointer to the new - string. This is equivalent to: - </para> - <programlisting>talloc_set_name_const(ptr, ptr)</programlisting> - </refsect2> - <refsect2><title>(type *)talloc_array(const void *ctx, type, uint_t count);</title> - <para> - The talloc_array() macro is equivalent to: - </para> - <programlisting>(type *)talloc_size(ctx, sizeof(type) * count);</programlisting> - <para> - except that it provides integer overflow protection for the - multiply, returning NULL if the multiply overflows. - </para> - </refsect2> - <refsect2><title>void *talloc_array_size(const void *ctx, size_t size, uint_t count);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>(typeof(ptr)) talloc_array_ptrtype(const void *ctx, ptr, uint_t count);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>void *talloc_realloc_fn(const void *ctx, void *ptr, size_t size)</title> - <para> - This is a non-macro version of talloc_realloc(), which is useful - as libraries sometimes want a realloc function pointer. A - realloc(3) implementation encapsulates the functionality of - malloc(3), free(3) and realloc(3) in one call, which is why it is - useful to be able to pass around a single function pointer. - </para> - </refsect2> - <refsect2><title>void *talloc_autofree_context(void);</title> - <para> - 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. - </para> - </refsect2> - <refsect2><title>void *talloc_check_name(const void *ptr, const char *name);</title> - <para> - This function checks if a pointer has the specified <emphasis - role="italic">name</emphasis>. If it does then the pointer is - returned. It it doesn't then NULL is returned. - </para> - </refsect2> - <refsect2><title>(type *)talloc_get_type(const void *ptr, type);</title> - <para> - This macro allows you to do type checking on talloc pointers. It - is particularly useful for void* private pointers. It is - equivalent to this: - </para> - <programlisting>(type *)talloc_check_name(ptr, #type)</programlisting> - </refsect2> - <refsect2><title>talloc_set_type(const void *ptr, type);</title> - <para> - This macro allows you to force the name of a pointer to be a - particular <emphasis>type</emphasis>. This can be - used in conjunction with talloc_get_type() to do type checking on - void* pointers. - </para> - <para> - It is equivalent to this: - </para> - <programlisting>talloc_set_name_const(ptr, #type)</programlisting> - </refsect2> - </refsect1> - <refsect1><title>PERFORMANCE</title> - <para> - All the additional features of talloc(3) over malloc(3) 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 10% 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. - </para> - </refsect1> - <refsect1><title>SEE ALSO</title> - <para> - malloc(3), strndup(3), vasprintf(3), asprintf(3), - <ulink url="http://talloc.samba.org/"/> - </para> - </refsect1> - <refsect1><title>COPYRIGHT/LICENSE</title> - <para> - Copyright (C) Andrew Tridgell 2004 - </para> - <para> - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or (at - your option) any later version. - </para> - <para> - This program 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 - General Public License for more details. - </para> - <para> - You should have received a copy of the GNU General Public License - along with this program; if not, see http://www.gnu.org/licenses/. - </para> - </refsect1> -</refentry> |