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<div id="preamble"><h1>Apache Module mod_slotmem_shm</h1>
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<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Slot-based shared memory provider.</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>slotmem_shm_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_slotmem_shm.c</td></tr></table>
<h3>Summary</h3>

    <p><code class="module"><a href="../mod/mod_slotmem_shm.html">mod_slotmem_shm</a></code> is a memory provider which
    provides for creation and access to a shared memory segment
    in which the datasets are organized in "slots."
    </p>

    <p>All shared memory is cleared and cleaned with each
    restart, whether graceful or not. The data itself is
    stored and restored within a file noted by the <code>name</code>
    parameter in the <code>create</code> and <code>attach</code>
    calls. If not specified with an absolute path, the file will be
    created relative to the path specified by the
    <code class="directive"><a href="../mod/core.html#defaultruntimedir">DefaultRuntimeDir</a></code> directive.
    </p>

    <p><code class="module"><a href="../mod/mod_slotmem_shm.html">mod_slotmem_shm</a></code> provides the following API functions:
    </p>

<pre class="prettyprint lang-c">/* call the callback on all worker slots */
apr_status_t doall(ap_slotmem_instance_t *s, ap_slotmem_callback_fn_t *func, void *data, apr_pool_t *pool)

/* create a new slotmem with each item size is item_size. 'name' is used to generate a filename for the persistent
   store of the shared memory if configured. Values are:
      "none"                - Anonymous shared memory and no persistent store
      "file-name"           - [DefaultRuntimeDir]/file-name
      "/absolute-file-name" - Absolute file name */
apr_status_t create(ap_slotmem_instance_t **new, const char *name, apr_size_t item_size, unsigned int item_num, ap_slotmem_type_t type, apr_pool_t *pool)

/* attach to an existing slotmem. See 'create()' for description of 'name' parameter */
apr_status_t attach(ap_slotmem_instance_t **new, const char *name, apr_size_t *item_size, unsigned int *item_num, apr_pool_t *pool)

/* get the direct pointer to the memory associated with this worker slot */
apr_status_t dptr(ap_slotmem_instance_t *s, unsigned int item_id, void **mem)

/* get/read the memory from this slot to dest */
apr_status_t get(ap_slotmem_instance_t *s, unsigned int item_id, unsigned char *dest, apr_size_t dest_len)

/* put/write the data from src to this slot */
apr_status_t put(ap_slotmem_instance_t *slot, unsigned int item_id, unsigned char *src, apr_size_t src_len)

/* return the total number of slots in the segment */
unsigned int num_slots(ap_slotmem_instance_t *s)

/* return the total data size, in bytes, of a slot in the segment */
apr_size_t slot_size(ap_slotmem_instance_t *s)

/* grab or allocate the first free slot and mark as in-use (does not do any data copying) */
apr_status_t grab(ap_slotmem_instance_t *s, unsigned int *item_id)

/* forced grab or allocate the specified slot and mark as in-use (does not do any data copying) */
apr_status_t fgrab(ap_slotmem_instance_t *s, unsigned int item_id)

/* release or free a slot and mark as not in-use (does not do any data copying) */
apr_status_t release(ap_slotmem_instance_t *s, unsigned int item_id)</pre>


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<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><h3 class="directives">Directives</h3>
<p>This module provides no
            directives.</p>
<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&amp;list_id=144532&amp;product=Apache%20httpd-2&amp;query_format=specific&amp;order=changeddate%20DESC%2Cpriority%2Cbug_severity&amp;component=mod_slotmem_shm">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&amp;component=mod_slotmem_shm">Report a bug</a></li></ul><h3>See also</h3>
<ul class="seealso">
<li><a href="#comments_section">Comments</a></li></ul></div>

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