glib-Memory-Chunks.html [plain text]
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Memory Chunks</title><meta name="generator" content="DocBook XSL Stylesheets V1.65.1"><link rel="home" href="index.html" title="GLib Reference Manual"><link rel="up" href="glib-data-types.html" title="GLib Data Types"><link rel="previous" href="glib-data-types.html" title="GLib Data Types"><link rel="next" href="glib-Doubly-Linked-Lists.html" title="Doubly-Linked Lists"><link rel="chapter" href="glib.html" title="GLib Overview"><link rel="refentry" href="glib-building.html" title="Compiling the GLib package"><link rel="refentry" href="glib-cross-compiling.html" title="Cross-compiling the GLib package"><link rel="refentry" href="glib-compiling.html" title="Compiling GLib Applications"><link rel="refentry" href="glib-running.html" title="Running GLib Applications"><link rel="refentry" href="glib-changes.html" title="Changes to GLib"><link rel="refentry" href="glib-resources.html" title="Mailing lists and bug reports"><link rel="chapter" href="glib-fundamentals.html" title="GLib Fundamentals"><link rel="refentry" href="glib-Basic-Types.html" title="Basic Types"><link rel="refentry" href="glib-Limits-of-Basic-Types.html" title="Limits of Basic Types"><link rel="refentry" href="glib-Standard-Macros.html" title="Standard Macros"><link rel="refentry" href="glib-Type-Conversion-Macros.html" title="Type Conversion Macros"><link rel="refentry" href="glib-Byte-Order-Macros.html" title="Byte Order Macros"><link rel="refentry" href="glib-Numerical-Definitions.html" title="Numerical Definitions"><link rel="refentry" href="glib-Miscellaneous-Macros.html" title="Miscellaneous Macros"><link rel="refentry" href="glib-Atomic-Operations.html" title="Atomic Operations"><link rel="chapter" href="glib-core.html" title="GLib Core Application Support"><link rel="refentry" href="glib-The-Main-Event-Loop.html" title="The Main Event Loop"><link rel="refentry" href="glib-Threads.html" title="
Threads"><link rel="refentry" href="glib-Thread-Pools.html" title="Thread Pools"><link rel="refentry" href="glib-Asynchronous-Queues.html" title="Asynchronous Queues"><link rel="refentry" href="glib-Dynamic-Loading-of-Modules.html" title="Dynamic Loading of Modules"><link rel="refentry" href="glib-Memory-Allocation.html" title="Memory Allocation"><link rel="refentry" href="glib-IO-Channels.html" title="IO Channels"><link rel="refentry" href="glib-Error-Reporting.html" title="Error Reporting"><link rel="refentry" href="glib-Warnings-and-Assertions.html" title="Message Output and Debugging Functions"><link rel="refentry" href="glib-Message-Logging.html" title="Message Logging"><link rel="chapter" href="glib-utilities.html" title="GLib Utilities"><link rel="refentry" href="glib-String-Utility-Functions.html" title="String Utility Functions"><link rel="refentry" href="glib-Character-Set-Conversion.html" title="Character Set Conversion"><link rel="refentry" href="glib-Unicode-Manipulation.html" title="Unicode Manipulation"><link rel="refentry" href="glib-I18N.html" title="Internationalization"><link rel="refentry" href="glib-Date-and-Time-Functions.html" title="Date and Time Functions"><link rel="refentry" href="glib-Random-Numbers.html" title="Random Numbers"><link rel="refentry" href="glib-Hook-Functions.html" title="Hook Functions"><link rel="refentry" href="glib-Miscellaneous-Utility-Functions.html" title="Miscellaneous Utility Functions"><link rel="refentry" href="glib-Lexical-Scanner.html" title="Lexical Scanner"><link rel="refentry" href="glib-Automatic-String-Completion.html" title="Automatic String Completion"><link rel="refentry" href="glib-Timers.html" title="Timers"><link rel="refentry" href="glib-Spawning-Processes.html" title="Spawning Processes"><link rel="refentry" href="glib-File-Utilities.html" title="File Utilities"><link rel="refentry" href="glib-Shell-related-Utilities.html" title="Shell-related Utilities"><link rel="refentry" href="glib-Glob-style-pattern-matching.html" title="Glob-style pattern matching"><link rel="refentry" href="glib-Simple-XML-Subset-Parser.html" title="Simple XML Subset Parser"><link rel="refentry" href="glib-Windows-Compatability-Functions.html" title="Windows Compatibility Functions"><link rel="chapter" href="glib-data-types.html" title="GLib Data Types"><link rel="refentry" href="glib-Memory-Chunks.html" title="Memory Chunks"><link rel="refentry" href="glib-Doubly-Linked-Lists.html" title="Doubly-Linked Lists"><link rel="refentry" href="glib-Singly-Linked-Lists.html" title="Singly-Linked Lists"><link rel="refentry" href="glib-Double-ended-Queues.html" title="Double-ended Queues"><link rel="refentry" href="glib-Trash-Stacks.html" title="Trash Stacks"><link rel="refentry" href="glib-Hash-Tables.html" title="Hash Tables"><link rel="refentry" href="glib-Strings.html" title="Strings"><link rel="refentry" href="glib-String-Chunks.html" title="String Chunks"><link rel="refentry" href="glib-Arrays.html" title="Arrays"><link rel="refentry" href="glib-Pointer-Arrays.html" title="Pointer Arrays"><link rel="refentry" href="glib-Byte-Arrays.html" title="Byte Arrays"><link rel="refentry" href="glib-Balanced-Binary-Trees.html" title="Balanced Binary Trees"><link rel="refentry" href="glib-N-ary-Trees.html" title="N-ary Trees"><link rel="refentry" href="glib-Quarks.html" title="Quarks"><link rel="refentry" href="glib-Keyed-Data-Lists.html" title="Keyed Data Lists"><link rel="refentry" href="glib-Datasets.html" title="Datasets"><link rel="refentry" href="glib-Relations-and-Tuples.html" title="Relations and Tuples"><link rel="refentry" href="glib-Caches.html" title="Caches"><link rel="refentry" href="glib-Memory-Allocators.html" title="Memory Allocators"><link rel="chapter" href="tools.html" title="GLib Tools"><link rel="refentry" href="glib-gettextize.html" title="glib-gettextize"><link rel="index" href="ix01.html" title="Index"><link rel="section" href="glib-Memory-Chunks.html#id3230143" title="Description"><link rel="section" href="glib-Memory-Chunks.html#id3229685" title="Details"><meta name="generator" content="GTK-Doc V1.2 (XML mode)"><link rel="stylesheet" href="style.css" type="text/css"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table class="navigation" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"><td><a accesskey="p" href="glib-data-types.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td><td><a accesskey="u" href="glib-data-types.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td><td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td><th width="100%" align="center">GLib Reference Manual</th><td><a accesskey="n" href="glib-Doubly-Linked-Lists.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td></tr></table><div class="refentry" lang="en"><a name="glib-Memory-Chunks"></a><div class="titlepage"><div></div><div></div></div><div class="refnamediv"><h2><span class="refentrytitle">Memory Chunks</span></h2><p>Memory Chunks — efficient way to allocate groups of equal-sized chunks of memory.</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
#include <glib.h>
struct <a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a>;
#define <a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS">G_ALLOC_AND_FREE</a>
#define <a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS">G_ALLOC_ONLY</a>
<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a>* <a href="glib-Memory-Chunks.html#g-mem-chunk-new">g_mem_chunk_new</a> (const <a href="glib-Basic-Types.html#gchar">gchar</a> *name,
<a href="glib-Basic-Types.html#gint">gint</a> atom_size,
<a href="glib-Basic-Types.html#gulong">gulong</a> area_size,
<a href="glib-Basic-Types.html#gint">gint</a> type);
<a href="glib-Basic-Types.html#gpointer">gpointer</a> <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc">g_mem_chunk_alloc</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
<a href="glib-Basic-Types.html#gpointer">gpointer</a> <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc0">g_mem_chunk_alloc0</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
void <a href="glib-Memory-Chunks.html#g-mem-chunk-free">g_mem_chunk_free</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk,
<a href="glib-Basic-Types.html#gpointer">gpointer</a> mem);
void <a href="glib-Memory-Chunks.html#g-mem-chunk-destroy">g_mem_chunk_destroy</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
#define <a href="glib-Memory-Chunks.html#g-mem-chunk-create">g_mem_chunk_create</a> (type, pre_alloc, alloc_type)
#define <a href="glib-Memory-Chunks.html#g-chunk-new">g_chunk_new</a> (type, chunk)
#define <a href="glib-Memory-Chunks.html#g-chunk-new0">g_chunk_new0</a> (type, chunk)
#define <a href="glib-Memory-Chunks.html#g-chunk-free">g_chunk_free</a> (mem, mem_chunk)
void <a href="glib-Memory-Chunks.html#g-mem-chunk-reset">g_mem_chunk_reset</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
void <a href="glib-Memory-Chunks.html#g-mem-chunk-clean">g_mem_chunk_clean</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
void <a href="glib-Memory-Chunks.html#g-blow-chunks">g_blow_chunks</a> (void);
void <a href="glib-Memory-Chunks.html#g-mem-chunk-info">g_mem_chunk_info</a> (void);
void <a href="glib-Memory-Chunks.html#g-mem-chunk-print">g_mem_chunk_print</a> (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);
</pre></div><div class="refsect1" lang="en"><a name="id3230143"></a><h2>Description</h2><p>
Memory chunks provide an efficient way to allocate equal-sized pieces of
memory, called atoms. They are used extensively within GLib itself.
For example, the
Doubly Linked Lists
use memory chunks to allocate space for elements of the lists.
</p><p>
There are two types of memory chunks, <a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a>, and <a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a>.
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a> chunks only allow allocation of atoms. The atoms can never
be freed individually. The memory chunk can only be free in its entirety.
</p></li><li><p>
<a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a> chunks do allow atoms to be freed individually.
The disadvantage of this is that the memory chunk has to keep track of which
atoms have been freed. This results in more memory being used and a slight
degradation in performance.
</p></li></ul></div><p>
</p><p>
To create a memory chunk use <a href="glib-Memory-Chunks.html#g-mem-chunk-new"><tt class="function">g_mem_chunk_new()</tt></a> or the convenience macro
<a href="glib-Memory-Chunks.html#g-mem-chunk-create"><tt class="function">g_mem_chunk_create()</tt></a>.
</p><p>
To allocate a new atom use <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc"><tt class="function">g_mem_chunk_alloc()</tt></a>, <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc0"><tt class="function">g_mem_chunk_alloc0()</tt></a>,
or the convenience macros <a href="glib-Memory-Chunks.html#g-chunk-new"><tt class="function">g_chunk_new()</tt></a> or <a href="glib-Memory-Chunks.html#g-chunk-new0"><tt class="function">g_chunk_new0()</tt></a>.
</p><p>
To free an atom use <a href="glib-Memory-Chunks.html#g-mem-chunk-free"><tt class="function">g_mem_chunk_free()</tt></a>, or the convenience macro
<a href="glib-Memory-Chunks.html#g-chunk-free"><tt class="function">g_chunk_free()</tt></a>. (Atoms can only be freed if the memory chunk is created
with the type set to <a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a>.)
</p><p>
To free any blocks of memory which are no longer being used, use
<a href="glib-Memory-Chunks.html#g-mem-chunk-clean"><tt class="function">g_mem_chunk_clean()</tt></a>. To clean all memory chunks, use <a href="glib-Memory-Chunks.html#g-blow-chunks"><tt class="function">g_blow_chunks()</tt></a>.
</p><p>
To reset the memory chunk, freeing all of the atoms, use <a href="glib-Memory-Chunks.html#g-mem-chunk-reset"><tt class="function">g_mem_chunk_reset()</tt></a>.
</p><p>
To destroy a memory chunk, use <a href="glib-Memory-Chunks.html#g-mem-chunk-destroy"><tt class="function">g_mem_chunk_destroy()</tt></a>.
</p><p>
To help debug memory chunks, use <a href="glib-Memory-Chunks.html#g-mem-chunk-info"><tt class="function">g_mem_chunk_info()</tt></a> and <a href="glib-Memory-Chunks.html#g-mem-chunk-print"><tt class="function">g_mem_chunk_print()</tt></a>.
</p><div class="example"><a name="id3230407"></a><p class="title"><b>Example 1. Using a <span class="structname">GMemChunk</span></b></p><pre class="programlisting">
GMemChunk *mem_chunk;
gchar *mem[10000];
gint i;
/* Create a GMemChunk with atoms 50 bytes long, and memory blocks holding
100 bytes. Note that this means that only 2 atoms fit into each memory
block and so isn't very efficient. */
mem_chunk = g_mem_chunk_new ("test mem chunk", 50, 100, G_ALLOC_AND_FREE);
/* Now allocate 10000 atoms. */
for (i = 0; i < 10000; i++)
{
mem[i] = g_chunk_new (gchar, mem_chunk);
/* Fill in the atom memory with some junk. */
for (j = 0; j < 50; j++)
mem[i][j] = i * j;
}
/* Now free all of the atoms. Note that since we are going to destroy the
GMemChunk, this wouldn't normally be used. */
for (i = 0; i < 10000; i++)
{
g_mem_chunk_free (mem_chunk, mem[i]);
}
/* We are finished with the GMemChunk, so we destroy it. */
g_mem_chunk_destroy (mem_chunk);
</pre></div><div class="example"><a name="id3230452"></a><p class="title"><b>Example 2. Using a <span class="structname">GMemChunk</span> with data structures</b></p><pre class="programlisting">
GMemChunk *array_mem_chunk;
GRealArray *array;
/* Create a GMemChunk to hold GRealArray structures, using the
g_mem_chunk_create() convenience macro. We want 1024 atoms in each
memory block, and we want to be able to free individual atoms. */
array_mem_chunk = g_mem_chunk_create (GRealArray, 1024, G_ALLOC_AND_FREE);
/* Allocate one atom, using the g_chunk_new() convenience macro. */
array = g_chunk_new (GRealArray, array_mem_chunk);
/* We can now use array just like a normal pointer to a structure. */
array->data = NULL;
array->len = 0;
array->alloc = 0;
array->zero_terminated = (zero_terminated ? 1 : 0);
array->clear = (clear ? 1 : 0);
array->elt_size = elt_size;
/* We can free the element, so it can be reused. */
g_chunk_free (array, array_mem_chunk);
/* We destroy the GMemChunk when we are finished with it. */
g_mem_chunk_destroy (array_mem_chunk);
</pre></div></div><div class="refsect1" lang="en"><a name="id3229685"></a><h2>Details</h2><div class="refsect2" lang="en"><a name="id3229691"></a><h3><a name="GMemChunk"></a>struct GMemChunk</h3><a class="indexterm" name="id2919283"></a><pre class="programlisting">struct GMemChunk;</pre><p>
The <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> struct is an opaque data structure representing a memory
chunk. It should be accessed only through the use of the following functions.
</p></div><hr><div class="refsect2" lang="en"><a name="id2919308"></a><h3><a name="G-ALLOC-AND-FREE-CAPS"></a>G_ALLOC_AND_FREE</h3><a class="indexterm" name="id2919317"></a><pre class="programlisting">#define G_ALLOC_AND_FREE 2
</pre><p>
Specifies the type of a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
Used in <a href="glib-Memory-Chunks.html#g-mem-chunk-new"><tt class="function">g_mem_chunk_new()</tt></a> and <a href="glib-Memory-Chunks.html#g-mem-chunk-create"><tt class="function">g_mem_chunk_create()</tt></a> to specify that atoms
will be freed individually.
</p></div><hr><div class="refsect2" lang="en"><a name="id2919362"></a><h3><a name="G-ALLOC-ONLY-CAPS"></a>G_ALLOC_ONLY</h3><a class="indexterm" name="id2919371"></a><pre class="programlisting">#define G_ALLOC_ONLY 1
</pre><p>
Specifies the type of a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
Used in <a href="glib-Memory-Chunks.html#g-mem-chunk-new"><tt class="function">g_mem_chunk_new()</tt></a> and <a href="glib-Memory-Chunks.html#g-mem-chunk-create"><tt class="function">g_mem_chunk_create()</tt></a> to specify that atoms
will never be freed individually.
</p></div><hr><div class="refsect2" lang="en"><a name="id3229733"></a><h3><a name="g-mem-chunk-new"></a>g_mem_chunk_new ()</h3><a class="indexterm" name="id3229742"></a><pre class="programlisting"><a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a>* g_mem_chunk_new (const <a href="glib-Basic-Types.html#gchar">gchar</a> *name,
<a href="glib-Basic-Types.html#gint">gint</a> atom_size,
<a href="glib-Basic-Types.html#gulong">gulong</a> area_size,
<a href="glib-Basic-Types.html#gint">gint</a> type);</pre><p>
Creates a new <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>name</tt></i> :</span></td><td>a string to identify the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>. It is not copied so it
should be valid for the lifetime of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>. It is only used in
<a href="glib-Memory-Chunks.html#g-mem-chunk-print"><tt class="function">g_mem_chunk_print()</tt></a>, which is used for debugging.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>atom_size</tt></i> :</span></td><td>the size, in bytes, of each element in the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>area_size</tt></i> :</span></td><td>the size, in bytes, of each block of memory allocated to contain
the atoms.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>type</tt></i> :</span></td><td>the type of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
<a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a> is used if the atoms will be freed individually.
<a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a> should be used if atoms will never be freed individually.
<a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a> is quicker, since it does not need to track free atoms,
but it obviously wastes memory if you no longer need many of the atoms.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>the new <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3231712"></a><h3><a name="g-mem-chunk-alloc"></a>g_mem_chunk_alloc ()</h3><a class="indexterm" name="id3231722"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gpointer">gpointer</a> g_mem_chunk_alloc (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Allocates an atom of memory from a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a pointer to the allocated atom.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3231794"></a><h3><a name="g-mem-chunk-alloc0"></a>g_mem_chunk_alloc0 ()</h3><a class="indexterm" name="id3231804"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gpointer">gpointer</a> g_mem_chunk_alloc0 (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Allocates an atom of memory from a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>, setting the memory to 0.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a pointer to the allocated atom.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3231877"></a><h3><a name="g-mem-chunk-free"></a>g_mem_chunk_free ()</h3><a class="indexterm" name="id3231887"></a><pre class="programlisting">void g_mem_chunk_free (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk,
<a href="glib-Basic-Types.html#gpointer">gpointer</a> mem);</pre><p>
Frees an atom in a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
This should only be called if the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> was created with
<a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a>. Otherwise it will simply return.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>mem</tt></i> :</span></td><td>a pointer to the atom to free.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3231986"></a><h3><a name="g-mem-chunk-destroy"></a>g_mem_chunk_destroy ()</h3><a class="indexterm" name="id3231996"></a><pre class="programlisting">void g_mem_chunk_destroy (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Frees all of the memory allocated for a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232059"></a><h3><a name="g-mem-chunk-create"></a>g_mem_chunk_create()</h3><a class="indexterm" name="id3232069"></a><pre class="programlisting">#define g_mem_chunk_create(type, pre_alloc, alloc_type)</pre><p>
A convenience macro for creating a new <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
It calls <a href="glib-Memory-Chunks.html#g-mem-chunk-new"><tt class="function">g_mem_chunk_new()</tt></a>, using the given type to create the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>
name. The atom size is determined using <tt class="function"><tt class="function">sizeof()</tt></tt>, and the
area size is calculated by multiplying the <i class="parameter"><tt>pre_alloc</tt></i> parameter with
the atom size.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>type</tt></i> :</span></td><td>the type of the atoms, typically a structure name.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>pre_alloc</tt></i> :</span></td><td>the number of atoms to store in each block of memory.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>alloc_type</tt></i> :</span></td><td>the type of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
<a href="glib-Memory-Chunks.html#G-ALLOC-AND-FREE-CAPS"><span class="type">G_ALLOC_AND_FREE</span></a> is used if the atoms will be freed individually.
<a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a> should be used if atoms will never be freed individually.
<a href="glib-Memory-Chunks.html#G-ALLOC-ONLY-CAPS"><span class="type">G_ALLOC_ONLY</span></a> is quicker, since it does not need to track free atoms,
but it obviously wastes memory if you no longer need many of the atoms.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>the new <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232235"></a><h3><a name="g-chunk-new"></a>g_chunk_new()</h3><a class="indexterm" name="id3232245"></a><pre class="programlisting">#define g_chunk_new(type, chunk)</pre><p>
A convenience macro to allocate an atom of memory from a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
It calls <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc"><tt class="function">g_mem_chunk_alloc()</tt></a> and casts the returned atom to a pointer to
the given type, avoiding a type cast in the source code.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>type</tt></i> :</span></td><td>the type of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> atoms, typically a structure name.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a pointer to the allocated atom, cast to a pointer to <i class="parameter"><tt>type</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232346"></a><h3><a name="g-chunk-new0"></a>g_chunk_new0()</h3><a class="indexterm" name="id3232356"></a><pre class="programlisting">#define g_chunk_new0(type, chunk)</pre><p>
A convenience macro to allocate an atom of memory from a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
It calls <a href="glib-Memory-Chunks.html#g-mem-chunk-alloc0"><tt class="function">g_mem_chunk_alloc0()</tt></a> and casts the returned atom to a pointer to
the given type, avoiding a type cast in the source code.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>type</tt></i> :</span></td><td>the type of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> atoms, typically a structure name.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a pointer to the allocated atom, cast to a pointer to <i class="parameter"><tt>type</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232458"></a><h3><a name="g-chunk-free"></a>g_chunk_free()</h3><a class="indexterm" name="id3232468"></a><pre class="programlisting">#define g_chunk_free(mem, mem_chunk)</pre><p>
A convenience macro to free an atom of memory from a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
It simply switches the arguments and calls <a href="glib-Memory-Chunks.html#g-mem-chunk-free"><tt class="function">g_mem_chunk_free()</tt></a>
It is included simply to complement the other convenience macros, <a href="glib-Memory-Chunks.html#g-chunk-new"><tt class="function">g_chunk_new()</tt></a>
and <a href="glib-Memory-Chunks.html#g-chunk-new0"><tt class="function">g_chunk_new0()</tt></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem</tt></i> :</span></td><td>a pointer to the atom to be freed.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232565"></a><h3><a name="g-mem-chunk-reset"></a>g_mem_chunk_reset ()</h3><a class="indexterm" name="id3232575"></a><pre class="programlisting">void g_mem_chunk_reset (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Resets a GMemChunk to its initial state.
It frees all of the currently allocated blocks of memory.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232630"></a><h3><a name="g-mem-chunk-clean"></a>g_mem_chunk_clean ()</h3><a class="indexterm" name="id3232640"></a><pre class="programlisting">void g_mem_chunk_clean (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Frees any blocks in a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> which are no longer being used.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3232702"></a><h3><a name="g-blow-chunks"></a>g_blow_chunks ()</h3><a class="indexterm" name="id3232712"></a><pre class="programlisting">void g_blow_chunks (void);</pre><p>
Calls <a href="glib-Memory-Chunks.html#g-mem-chunk-clean"><tt class="function">g_mem_chunk_clean()</tt></a> on all <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> objects.
</p></div><hr><div class="refsect2" lang="en"><a name="id3232752"></a><h3><a name="g-mem-chunk-info"></a>g_mem_chunk_info ()</h3><a class="indexterm" name="id3232762"></a><pre class="programlisting">void g_mem_chunk_info (void);</pre><p>
Outputs debugging information for all <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> objects currently in use.
It outputs the number of <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> objects currently allocated,
and calls <a href="glib-Memory-Chunks.html#g-mem-chunk-print"><tt class="function">g_mem_chunk_print()</tt></a> to output information on each one.
</p></div><hr><div class="refsect2" lang="en"><a name="id3232813"></a><h3><a name="g-mem-chunk-print"></a>g_mem_chunk_print ()</h3><a class="indexterm" name="id3232823"></a><pre class="programlisting">void g_mem_chunk_print (<a href="glib-Memory-Chunks.html#GMemChunk">GMemChunk</a> *mem_chunk);</pre><p>
Outputs debugging information for a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
It outputs the name of the <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a> (set with <a href="glib-Memory-Chunks.html#g-mem-chunk-new"><tt class="function">g_mem_chunk_new()</tt></a>),
the number of bytes used, and the number of blocks of memory allocated.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>mem_chunk</tt></i> :</span></td><td>a <a href="glib-Memory-Chunks.html#GMemChunk"><span class="type">GMemChunk</span></a>.
</td></tr></tbody></table></div></div></div></div><table class="navigation" width="100%" summary="Navigation footer" cellpadding="2" cellspacing="0"><tr valign="middle"><td align="left"><a accesskey="p" href="glib-data-types.html"><b><< GLib Data Types</b></a></td><td align="right"><a accesskey="n" href="glib-Doubly-Linked-Lists.html"><b>Doubly-Linked Lists >></b></a></td></tr></table></body></html>