-<h2>vm_inherit</h2>
\r<hr>
\r<p>
\r<strong>Function</strong> - Set a VM region's inheritance attribute.
\r<p>
\r<h3>SYNOPSIS</h3>
\r<pre>
\r<strong>kern_return_t vm_inherit</strong>
\r <strong>(vm_task_t</strong> <var>target_task</var>,
\r <strong>vm_address_t</strong> <var>address</var>,
\r <strong>vm_size_t</strong> <var>size</var>,
\r <strong>vm_inherit_t</strong> <var>new_inheritance</var><strong>);</strong>
\r</pre>
\r<h3>PARAMETERS</h3>
\r<dl>
\r<p>
\r<dt> <var>target_task</var>
\r<dd>
\r[in task send right]
\rThe port for the task whose address space contains
\rthe region.
\r<p>
\r<dt> <var>address</var>
\r<dd>
\r[in scalar]
\rThe starting address for the region.
\r<p>
\r<dt> <var>size</var>
\r<dd>
\r[in scalar]
\rThe number of bytes in the region.
\r<p>
\r<dt> <var>new_inheritance</var>
\r<dd>
\r[in scalar]
\rThe new inheritance attribute for the region. Valid values are:
\r<dl>
\r<p>
\r<dt> <strong>VM_INHERIT_SHARE</strong>
\r<dd>
\rAllows child tasks to share the region.
\r<p>
\r<dt> <strong>VM_INHERIT_COPY</strong>
\r<dd>
\rGives child tasks a copy of the region.
\r<p>
\r<dt> <strong>VM_INHERIT_NONE</strong>
\r<dd>
\rProvides no access to the region for child tasks.
\r</dl>
\r</dl>
\r<h3>DESCRIPTION</h3>
\r<p>
\rThe <strong>vm_inherit</strong> function sets the inheritance attribute
\rfor a region within the
\rspecified task's address space. The inheritance attribute determines
\rthe type of
\raccess established for child tasks at task creation.
\r<p>
\rBecause inheritance applies to virtual pages, the specified <var>address</var>
\rand <var>size</var> are
\rrounded to page boundaries, as follows: the region starts at
\rthe beginning of the
\rvirtual page containing <var>address</var>; it ends at the end of the virtual
\rpage containing
\r<var>address</var> + <var>size</var> - 1.
\rBecause of this rounding to virtual page boundaries, the
\ramount of memory affected may be greater than <var>size</var>. Use
\r<strong>host_page_size</strong> to find the current virtual page size.
\r<p>
\rA parent and a child task can share the same physical memory only if the
\rinheritance for the memory is set to <strong>VM_INHERIT_SHARE</strong> before
\rthe child task is
\rcreated. Other than through the use of an external memory manager (see
\r<strong>vm_map</strong>), this is the only way that two tasks can share memory.
\r<p>
\rNote that all the threads within a task share the task's memory.
\r<h3>NOTES</h3>
\r<p>
\rThis interface is machine word length specific because of the virtual address
\rparameter.
\r<h3>RETURN VALUES</h3>
\r<dl>
\r<p>
\r<dt> <strong>KERN_INVALID_ADDRESS</strong>
\r<dd>
\rThe address is illegal or specifies a non-allocated region.
\r</dl>
\r<h3>RELATED INFORMATION</h3>
\r<p>
\rFunctions:
\r<a href="task_create.html"><strong>task_create</strong></a>,
\r<a href="vm_map.html"><strong>vm_map</strong></a>,
\r<a href="vm_region.html"><strong>vm_region</strong></a>,
\r<a href="norma_task_clone.html"><strong>norma_task_create</strong></a>.
\r\ No newline at end of file
+<h2>vm_inherit</h2>
+<hr>
+<p>
+<strong>Function</strong> - Set a VM region's inheritance attribute.
+<p>
+<h3>SYNOPSIS</h3>
+<pre>
+<strong>kern_return_t vm_inherit</strong>
+ <strong>(vm_task_t</strong> <var>target_task</var>,
+ <strong>vm_address_t</strong> <var>address</var>,
+ <strong>vm_size_t</strong> <var>size</var>,
+ <strong>vm_inherit_t</strong> <var>new_inheritance</var><strong>);</strong>
+</pre>
+<h3>PARAMETERS</h3>
+<dl>
+<p>
+<dt> <var>target_task</var>
+<dd>
+[in task send right]
+The port for the task whose address space contains
+the region.
+<p>
+<dt> <var>address</var>
+<dd>
+[in scalar]
+The starting address for the region.
+<p>
+<dt> <var>size</var>
+<dd>
+[in scalar]
+The number of bytes in the region.
+<p>
+<dt> <var>new_inheritance</var>
+<dd>
+[in scalar]
+The new inheritance attribute for the region. Valid values are:
+<dl>
+<p>
+<dt> <strong>VM_INHERIT_SHARE</strong>
+<dd>
+Allows child tasks to share the region.
+<p>
+<dt> <strong>VM_INHERIT_COPY</strong>
+<dd>
+Gives child tasks a copy of the region.
+<p>
+<dt> <strong>VM_INHERIT_NONE</strong>
+<dd>
+Provides no access to the region for child tasks.
+</dl>
+</dl>
+<h3>DESCRIPTION</h3>
+<p>
+The <strong>vm_inherit</strong> function sets the inheritance attribute
+for a region within the
+specified task's address space. The inheritance attribute determines
+the type of
+access established for child tasks at task creation.
+<p>
+Because inheritance applies to virtual pages, the specified <var>address</var>
+and <var>size</var> are
+rounded to page boundaries, as follows: the region starts at
+the beginning of the
+virtual page containing <var>address</var>; it ends at the end of the virtual
+page containing
+<var>address</var> + <var>size</var> - 1.
+Because of this rounding to virtual page boundaries, the
+amount of memory affected may be greater than <var>size</var>. Use
+<strong>host_page_size</strong> to find the current virtual page size.
+<p>
+A parent and a child task can share the same physical memory only if the
+inheritance for the memory is set to <strong>VM_INHERIT_SHARE</strong> before
+the child task is
+created. Other than through the use of an external memory manager (see
+<strong>vm_map</strong>), this is the only way that two tasks can share memory.
+<p>
+Note that all the threads within a task share the task's memory.
+<h3>NOTES</h3>
+<p>
+This interface is machine word length specific because of the virtual address
+parameter.
+<h3>RETURN VALUES</h3>
+<dl>
+<p>
+<dt> <strong>KERN_INVALID_ADDRESS</strong>
+<dd>
+The address is illegal or specifies a non-allocated region.
+</dl>
+<h3>RELATED INFORMATION</h3>
+<p>
+Functions:
+<a href="task_create.html"><strong>task_create</strong></a>,
+<a href="vm_map.html"><strong>vm_map</strong></a>,
+<a href="vm_region.html"><strong>vm_region</strong></a>,
+<a href="norma_task_clone.html"><strong>norma_task_create</strong></a>.
projects / apple / xnu.git / blobdiff