osfmk/man/norma_task_clone.html

   1 <h2>norma_task_clone</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Create a remote task that shares access to parent task's memory regardless of inheritance attributes.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   norma_task_clone</strong>
   8                 <strong>(task_t</strong>                             <var>parent_task</var>,
   9                  <strong>boolean_t</strong>                       <var>inherit_memory</var>,
  10                  <strong>int</strong>                                 <var>child_node</var>,
  11                  <strong>task_t</strong>                              <var>child_task</var><strong>);</strong>
  12 </pre>
  13 <h3>PARAMETERS</h3>
  14 <dl>
  15 <p>
  16 <dt> <var>parent_task</var>
  17 <dd>
  18 [in task send right]
  19 The port for the task from which to draw the child
  20 task's port rights, resource limits, and address space.
  21 <p>
  22 <dt> <var>inherit_memory</var>
  23 <dd>
  24 [in scalar]
  25 Address space inheritance indicator.  If true, the child task
  26 inherits the address space of the parent task.  If false, the kernel assigns
  27 the child task an empty address space.
  28 <p>
  29 <dt> <var>child_node</var>
  30 <dd>
  31 [in scalar]
  32 The node index of the node on which to create the child.
  33 <p>
  34 <dt> <var>child_task</var>
  35 <dd>
  36 [out task send right]
  37 The kernel-assigned port name for the new task.
  38 </dl>
  39 <h3>DESCRIPTION</h3>
  40 <p>
  41 The <strong>norma_task_clone</strong> function "clones" a new task from
  42 <var>parent_task</var> on the specified <var>node</var> and returns the name
  43 of the new task in <var>child_task</var>.  The child
  44 task acquires shared parts of the parent's
  45 address space (see <strong>vm_inherit</strong>)
  46 regardless of the inheritance set for the parent's memory regions, although the
  47 inheritance for the child's regions will be set to that of the
  48 parent's regions.  The child
  49 task initially contains no threads.
  50 <p>
  51 By way of comparison, tasks created by the standard <strong>task_create</strong>
  52 primitive are created on the same node as the parent.
  53 <p>
  54 Other than being created on a different node, the new task has the same
  55 properties as if created by <strong>task_create</strong>.
  56 <h3>NOTES</h3>
  57 <p>
  58 This call differs from <strong>norma_task_create</strong> in that the
  59 inheritance set for the
  60 parent's memory regions is ignored; the child always shares memory with the
  61 parent.
  62 <p>
  63 This call is intended to support process migration, where the inheritance
  64 semantics of <strong>norma_task_create</strong> would break migrated
  65 programs that depended upon
  66 sharing relationships remaining after migration.
  67 <p>
  68 This call is not a true task migration call, in that it does
  69 not migrate the port
  70 space, threads, and other non-address-space attributes of the task.
  71 <h3>RETURN VALUES</h3>
  72 <p>
  73 Only generic errors apply.
  74 <h3>RELATED INFORMATION</h3>
  75 <p>
  76 Functions:
  77 <a href="task_create.html"><strong>task_create</strong></a>,
  78 <a href="norma_task_create.html"><strong>norma_task_create</strong></a>.