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200 <h1>Use custom allocators for embedded usage
<a class=
"headerlink" href=
"#use-custom-allocators-for-embedded-usage" title=
"Permalink to this headline">¶
</a></h1>
201 <p>Manage memory allocator functions
</p>
202 <div class=
"section" id=
"synopsis">
203 <h2>SYNOPSIS
<a class=
"headerlink" href=
"#synopsis" title=
"Permalink to this headline">¶
</a></h2>
205 <dt>#include
<libmemcached/memcached.h
></dt><dd><p>Compile and link with -lmemcached
</p>
208 <dl class=
"function">
209 <dt id=
"_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv">
210 <span id=
"_CPPv331memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv"></span><span id=
"_CPPv231memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv"></span><span id=
"memcached_set_memory_allocators__memcached_stP.memcached_malloc_fn.memcached_free_fn.memcached_realloc_fn.memcached_calloc_fn.voidP"></span><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> <code class=
"sig-name descname">memcached_set_memory_allocators
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em>,
<a class=
"reference internal" href=
"#_CPPv419memcached_malloc_fn" title=
"memcached_malloc_fn">memcached_malloc_fn
</a> <em>mem_malloc
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_free_fn" title=
"memcached_free_fn">memcached_free_fn
</a> <em>mem_free
</em>,
<a class=
"reference internal" href=
"#_CPPv420memcached_realloc_fn" title=
"memcached_realloc_fn">memcached_realloc_fn
</a> <em>mem_realloc
</em>,
<a class=
"reference internal" href=
"#_CPPv419memcached_calloc_fn" title=
"memcached_calloc_fn">memcached_calloc_fn
</a> <em>mem_calloc
</em>, void *
<em>context
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title=
"Permalink to this definition">¶
</a><br /></dt>
213 <dl class=
"function">
214 <dt id=
"_CPPv431memcached_get_memory_allocatorsP12memcached_stP19memcached_malloc_fnP17memcached_free_fnP20memcached_realloc_fnP19memcached_calloc_fn">
215 <span id=
"_CPPv331memcached_get_memory_allocatorsP12memcached_stP19memcached_malloc_fnP17memcached_free_fnP20memcached_realloc_fnP19memcached_calloc_fn"></span><span id=
"_CPPv231memcached_get_memory_allocatorsP12memcached_stP19memcached_malloc_fnP17memcached_free_fnP20memcached_realloc_fnP19memcached_calloc_fn"></span><span id=
"memcached_get_memory_allocators__memcached_stP.memcached_malloc_fnP.memcached_free_fnP.memcached_realloc_fnP.memcached_calloc_fnP"></span>void
<code class=
"sig-name descname">memcached_get_memory_allocators
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em>,
<a class=
"reference internal" href=
"#_CPPv419memcached_malloc_fn" title=
"memcached_malloc_fn">memcached_malloc_fn
</a> *
<em>mem_malloc
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_free_fn" title=
"memcached_free_fn">memcached_free_fn
</a> *
<em>mem_free
</em>,
<a class=
"reference internal" href=
"#_CPPv420memcached_realloc_fn" title=
"memcached_realloc_fn">memcached_realloc_fn
</a> *
<em>mem_realloc
</em>,
<a class=
"reference internal" href=
"#_CPPv419memcached_calloc_fn" title=
"memcached_calloc_fn">memcached_calloc_fn
</a> *
<em>mem_calloc
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv431memcached_get_memory_allocatorsP12memcached_stP19memcached_malloc_fnP17memcached_free_fnP20memcached_realloc_fnP19memcached_calloc_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
218 <dl class=
"function">
219 <dt id=
"_CPPv439memcached_get_memory_allocators_contextPK12memcached_st">
220 <span id=
"_CPPv339memcached_get_memory_allocators_contextPK12memcached_st"></span><span id=
"_CPPv239memcached_get_memory_allocators_contextPK12memcached_st"></span><span id=
"memcached_get_memory_allocators_context__memcached_stCP"></span>void *
<code class=
"sig-name descname">memcached_get_memory_allocators_context
</code><span class=
"sig-paren">(
</span><em class=
"property">const
</em> <a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv439memcached_get_memory_allocators_contextPK12memcached_st" title=
"Permalink to this definition">¶
</a><br /></dt>
224 <dt id=
"_CPPv419memcached_malloc_fn">
225 <span id=
"_CPPv319memcached_malloc_fn"></span><span id=
"_CPPv219memcached_malloc_fn"></span><span id=
"memcached_malloc_fn"></span><em class=
"property">typedef
</em>void *(*
<code class=
"sig-name descname">memcached_malloc_fn
</code>)
<span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *ptr,
<em class=
"property">const
</em> size_t size, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv419memcached_malloc_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
229 <dt id=
"_CPPv420memcached_realloc_fn">
230 <span id=
"_CPPv320memcached_realloc_fn"></span><span id=
"_CPPv220memcached_realloc_fn"></span><span id=
"memcached_realloc_fn"></span><em class=
"property">typedef
</em>void *(*
<code class=
"sig-name descname">memcached_realloc_fn
</code>)
<span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *ptr, void *mem,
<em class=
"property">const
</em> size_t size, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv420memcached_realloc_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
234 <dt id=
"_CPPv417memcached_free_fn">
235 <span id=
"_CPPv317memcached_free_fn"></span><span id=
"_CPPv217memcached_free_fn"></span><span id=
"memcached_free_fn"></span><em class=
"property">typedef
</em>void (*
<code class=
"sig-name descname">memcached_free_fn
</code>)
<span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *ptr, void *mem, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv417memcached_free_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
239 <dt id=
"_CPPv419memcached_calloc_fn">
240 <span id=
"_CPPv319memcached_calloc_fn"></span><span id=
"_CPPv219memcached_calloc_fn"></span><span id=
"memcached_calloc_fn"></span><em class=
"property">typedef
</em>void *(*
<code class=
"sig-name descname">memcached_calloc_fn
</code>)
<span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *ptr, size_t nelem,
<em class=
"property">const
</em> size_t elsize, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv419memcached_calloc_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
244 <div class=
"section" id=
"description">
245 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
246 <p><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">libmemcached
</span></code> allows you to specify your own memory allocators, optimized for
247 your application. This enables libmemcached to be used inside of applications
248 that have their own malloc implementation.
</p>
249 <p><a class=
"reference internal" href=
"#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title=
"memcached_set_memory_allocators"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_set_memory_allocators()
</span></code></a> is used to set the memory allocators
250 used by the memcached instance specified by ptr. Please note that you cannot
251 override only one of the memory allocators, you have to specify a complete new
252 set if you want to override one of them. All of the memory allocation functions
253 should behave as specified in the C99 standard. Specify NULL as all functions to
254 reset them to the default values.
</p>
255 <p><a class=
"reference internal" href=
"#_CPPv431memcached_get_memory_allocatorsP12memcached_stP19memcached_malloc_fnP17memcached_free_fnP20memcached_realloc_fnP19memcached_calloc_fn" title=
"memcached_get_memory_allocators"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_get_memory_allocators()
</span></code></a> is used to get the currently used memory
256 allocators by a memcached handle.
</p>
257 <p><a class=
"reference internal" href=
"#_CPPv439memcached_get_memory_allocators_contextPK12memcached_st" title=
"memcached_get_memory_allocators_context"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_get_memory_allocators_context()
</span></code></a> returns the void * that was
258 passed in during the call to
<a class=
"reference internal" href=
"#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title=
"memcached_set_memory_allocators"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_set_memory_allocators()
</span></code></a>.
</p>
259 <p>The first argument to the memory allocator functions is a pointer to a memcached
260 structure, the is passed as const and you will need to clone it in order to make
261 use of any operation which would modify it.
</p>
263 <div class=
"section" id=
"notes">
264 <h2>NOTES
<a class=
"headerlink" href=
"#notes" title=
"Permalink to this headline">¶
</a></h2>
265 <p>In version
0.38 all functions were modified to have a context void pointer
266 passed to them. This was so that customer allocators could have their own space
269 <div class=
"section" id=
"return-value">
270 <h2>RETURN VALUE
<a class=
"headerlink" href=
"#return-value" title=
"Permalink to this headline">¶
</a></h2>
271 <p><a class=
"reference internal" href=
"#_CPPv431memcached_set_memory_allocatorsP12memcached_st19memcached_malloc_fn17memcached_free_fn20memcached_realloc_fn19memcached_calloc_fnPv" title=
"memcached_set_memory_allocators"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_set_memory_allocators()
</span></code></a> return
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_SUCCESSE" title=
"MEMCACHED_SUCCESS"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">MEMCACHED_SUCCESS
</span></code></a> upon success,
272 and
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv4N18memcached_return_t17MEMCACHED_FAILUREE" title=
"MEMCACHED_FAILURE"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">MEMCACHED_FAILURE
</span></code></a> if you don’t pass a complete set of function pointers.
</p>
274 <div class=
"section" id=
"see-also">
275 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
277 <li><p><em class=
"manpage"><a class=
"manpage reference external" href=
"http://man7.org/linux/man-pages/man1/memcached.1.html">memcached(
1)
</a></em></p></li>
278 <li><p><a class=
"reference internal" href=
"../libmemcached.html"><span class=
"doc">C/C++ Client Library for memcached
</span></a></p></li>
279 <li><p><a class=
"reference internal" href=
"memcached_strerror.html"><span class=
"doc">Converting Error Codes to Messages
</span></a></p></li>
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"rst-footer-buttons" role=
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"footer navigation">
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