[apple/xnu.git] / osfmk / man / DP_backing_store_info.html

<h2>default_pager_backing_store_info</h2>\r<hr>\r<p>\r<strong>Server Interface</strong> - Return information about a backing storage object.\r<h3>SYNOPSIS</h3>\r<pre>\r<strong>#include&lt default_pager/mach/default_pager_types.h&gt</strong>\r\r<strong>kern_return_t   default_pager_backing_store_info</strong>\r                <strong>(mach_port_t</strong>                      <var>backing_store</var>,\r                 <strong>backing_store_flavor_t</strong>                  <var>flavor</var>,\r                 <strong>backing_store_info_t</strong>                      <var>info</var>,\r                 <strong>mach_msg_type_number_t</strong>                    <var>size</var><strong>);</strong>\r</pre>\r<h3>PARAMETERS</h3>\r<dl>\r<p>\r<dt> <var>backing_store</var>\r<dd>\r[in backing store (receive) right] The backing store port for which\rinformation is desired.\r<p>\r<dt> <var>flavor</var>\r<dd>\r[in scalar] The type of information to be returned. Valid values are:\r<p>\r<dt> <var>BACKING_STORE_BASIC_INFO</var>\r<dd>\rStatistical and space used/available information. It includes \rthe priority and cluster size that was provided in the \rdefault_pager_backing_store_create call.\r<p>\r<dt> <var>info</var>\r<dd>\r[pointer to in structure] The data structure that will be filled in with the \rinformation provided for the requested flavor.\r<p>\r<dt> <var>size</var>\r<dd>\r[pointer to in/out scalar] On input, the maximum size of the info data \rstructure; on output, the actual size of the returned data.\r</dl>\r<h3>DESCRIPTION</h3>\r<p>\rThe <strong>default_pager_backing_store_info</strong> function is called to obtain\rinformation about a backing storage object created by\r<strong>default_pager_backing_store_create</strong>. The kernel does not make this call\ritself (which is why it can be a synchronous call); this request is\ronly issued by tasks holding the backing store port, created with\r<strong>default_pager_backing_store_create</strong>, for a default memory manager.\r<h3>RETURN VALUES</h3>\r<dl>\r<p>\r<dt> <strong>KERN_FAILURE</strong>\r<dd>\rThe default pager does not support this operation.\r<p>\r<dt> <strong>KERN_INVALID_ARGUMENT</strong>\r<dd>\rThe backing_store port does not represent a valid backing store, flavor \ris not valid, or size is not the size for the requested flavor.\r<p>\r<dt> <strong>KERN_SUCCESS</strong>\r<dd>\rThe operation was successful.\r</dl>\r<h3>RELATED INFORMATION</h3>\r<p>\rFunctions:\r<a href="DP_backing_store_create.html"><strong>default_pager_backing_store_create</strong></a>,\r<a href="DP_backing_store_delete.html"><strong>default_pager_backing_store_delete</strong></a>.\r<p>\rData Structures:\rbacking_store_basic_info.\r