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<a href="#func-members">Functions</a> </div>
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<h1>Pool Debugging functions.</h1> </div>
<div class="ingroups"><a class="el" href="group__apr__pools.html">Memory Pool Functions</a></div></div>
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<table class="memberdecls">
<tr><td colspan="2"><h2><a name="func-members"></a>
Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group___pool_debug.html#gaecd956092f81c70117507ad8cbca8ea7">apr_pool_join</a> (<a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> *p, <a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> *sub)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="group___pool_debug.html#ga0bc40d9069709020e3643492dae2ccb0">apr_pool_find</a> (const void *mem)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">apr_size_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group___pool_debug.html#ga22462da23d70dfde389a370b131cd351">apr_pool_num_bytes</a> (<a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> *p, int recurse)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group___pool_debug.html#ga24f8f0287478fa71f77d0ce4ec035e4a">apr_pool_lock</a> (<a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> *pool, int flag)</td></tr>
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<hr/><a name="_details"></a><h2>Detailed Description</h2>
<p>pools have nested lifetimes -- sub_pools are destroyed when the parent pool is cleared. We allow certain liberties with operations on things such as tables (and on other structures in a more general sense) where we allow the caller to insert values into a table which were not allocated from the table's pool. The table's data will remain valid as long as all the pools from which its values are allocated remain valid.</p>
<p>For example, if B is a sub pool of A, and you build a table T in pool B, then it's safe to insert data allocated in A or B into T (because B lives at most as long as A does, and T is destroyed when B is cleared/destroyed). On the other hand, if S is a table in pool A, it is safe to insert data allocated in A into S, but it is *not safe* to insert data allocated from B into S... because B can be cleared/destroyed before A is (which would leave dangling pointers in T's data structures).</p>
<p>In general we say that it is safe to insert data into a table T if the data is allocated in any ancestor of T's pool. This is the basis on which the APR_POOL_DEBUG code works -- it tests these ancestor relationships for all data inserted into tables. APR_POOL_DEBUG also provides tools (apr_pool_find, and apr_pool_is_ancestor) for other folks to implement similar restrictions for their own data structures.</p>
<p>However, sometimes this ancestor requirement is inconvenient -- sometimes it's necessary to create a sub pool where the sub pool is guaranteed to have the same lifetime as the parent pool. This is a guarantee implemented by the *caller*, not by the pool code. That is, the caller guarantees they won't destroy the sub pool individually prior to destroying the parent pool.</p>
<p>In this case the caller must call <a class="el" href="group___pool_debug.html#gaecd956092f81c70117507ad8cbca8ea7">apr_pool_join()</a> to indicate this guarantee to the APR_POOL_DEBUG code.</p>
<p>These functions are only implemented when <a class="el" href="group__apr__pools.html#gad898431056ee6f544e0632f2cf5706c4">APR_POOL_DEBUG</a> is set. </p>
<hr/><h2>Function Documentation</h2>
<a class="anchor" id="ga0bc40d9069709020e3643492dae2ccb0"></a><!-- doxytag: member="apr_pools.h::apr_pool_find" ref="ga0bc40d9069709020e3643492dae2ccb0" args="(const void *mem)" -->
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<td class="memname"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a>* apr_pool_find </td>
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<p>Find a pool from something allocated in it. </p>
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>The thing allocated in the pool </td></tr>
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</dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>The pool it is allocated in </dd></dl>
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<a class="anchor" id="gaecd956092f81c70117507ad8cbca8ea7"></a><!-- doxytag: member="apr_pools.h::apr_pool_join" ref="gaecd956092f81c70117507ad8cbca8ea7" args="(apr_pool_t *p, apr_pool_t *sub)" -->
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<td class="memname">void apr_pool_join </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td>
<td class="paramname"><em>p</em>, </td>
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<td class="paramtype"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td>
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<p>Guarantee that a subpool has the same lifetime as the parent. </p>
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">p</td><td>The parent pool </td></tr>
<tr><td class="paramname">sub</td><td>The subpool </td></tr>
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</dd>
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</div>
<a class="anchor" id="ga24f8f0287478fa71f77d0ce4ec035e4a"></a><!-- doxytag: member="apr_pools.h::apr_pool_lock" ref="ga24f8f0287478fa71f77d0ce4ec035e4a" args="(apr_pool_t *pool, int flag)" -->
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<td class="memname">void apr_pool_lock </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td>
<td class="paramname"><em>pool</em>, </td>
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<td class="paramtype">int </td>
<td class="paramname"><em>flag</em> </td>
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<td>)</td>
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<p>Lock a pool </p>
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">pool</td><td>The pool to lock </td></tr>
<tr><td class="paramname">flag</td><td>The flag </td></tr>
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</dd>
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<a class="anchor" id="ga22462da23d70dfde389a370b131cd351"></a><!-- doxytag: member="apr_pools.h::apr_pool_num_bytes" ref="ga22462da23d70dfde389a370b131cd351" args="(apr_pool_t *p, int recurse)" -->
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<td class="memname">apr_size_t apr_pool_num_bytes </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td>
<td class="paramname"><em>p</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>recurse</em> </td>
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<td></td>
<td>)</td>
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<p>Report the number of bytes currently in the pool </p>
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">p</td><td>The pool to inspect </td></tr>
<tr><td class="paramname">recurse</td><td>Recurse/include the subpools' sizes </td></tr>
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</dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>The number of bytes </dd></dl>
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