osfmk/man/DP_object_create.html

   1 <h2>default_pager_object_create</h2>
   2 <hr>
   3 <p>
   4 <strong>Server Interface</strong> - Initialize a non-persistent memory object suitable for sharing between tasks.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   default_pager_object_create</strong>
   8                 <strong>(mach_port_t</strong>                              <var>pager</var>,
   9                  <strong>memory_object_t</strong>                 <var>*memory_object</var>,
  10                  <strong>vm_size_t</strong>                          <var>object_size</var><strong>);</strong>
  11
  12
  13 <strong>kern_return_t   seqnos_default_pager_object_create</strong>
  14                 <strong>(mach_port_t</strong>                              <var>pager</var>,
  15                  <strong>mach_port_seqno_t</strong>                        <var>seqno</var>,
  16                  <strong>memory_object_t</strong>                 <var>*memory_object</var>,
  17                  <strong>vm_size_t</strong>                          <var>object_size</var><strong>);</strong>
  18 </pre>
  19 <h3>PARAMETERS</h3>
  20 <dl>
  21 <p>
  22 <dt> <var>pager</var>
  23 <dd>
  24 [in default-pager (receive) right]
  25 The default memory manager service
  26 port.
  27 <p>
  28 <dt> <var>seqno</var>
  29 <dd>
  30 [in scalar]
  31 The sequence number of this message relative to the <var>pager</var>
  32 port.
  33 <p>
  34 <dt> <var>memory_object</var>
  35 <dd>
  36 [out memory-object send right]
  37 A memory object port (with full access) for the memory object.
  38 <p>
  39 <dt> <var>object_size</var>
  40 <dd>
  41 [in scalar]
  42 The maximum size for the memory object.
  43 </dl>
  44 <h3>DESCRIPTION</h3>
  45 <p>
  46 A <strong>default_pager_object_create</strong> function is called as
  47 the result of a message
  48 requesting that the default memory manager create and return a (shared) memory
  49 object which is suitable for use with <strong>vm_map</strong>.  This memory object has
  50 the same properties as does a memory object provided by
  51 <strong>vm_allocate</strong>: its initial
  52 contents are zero and the backing contents are temporary in that they do not
  53 persist after the memory object is destroyed.  The memory object
  54 is suitable for use
  55 as non-permanent shared memory.  The kernel does not make this call itself
  56 (which is why it can be a synchronous call); this request is only issued by
  57 (privileged) tasks holding the default memory manager port.
  58 This call should be
  59 contrasted with the kernel's <strong>memory_object_create</strong> message, in which
  60 the memory cache object is already created and the identity of the abstract
  61 memory object is made known to the default manager.
  62 <h3>RETURN VALUES</h3>
  63 <p>
  64 Only generic errors apply.
  65 <h3>RELATED INFORMATION</h3>
  66 <p>
  67 Functions:
  68 <a href="vm_map.html"><strong>vm_map</strong></a>,
  69 <a href="HD_memory_manager.html"><strong>host_default_memory_manager</strong></a>,
  70 <a href="memory_object_create.html"><strong>memory_object_create</strong></a>,
  71 <a href="MO_default_server.html"><strong>memory_object_default_server</strong></a>,
  72 <a href="SMO_default_server.html"><strong>seqnos_memory_object_default_server</strong></a>.