1<h2>memory_object_data_unlock</h2>
2<hr>
3<p>
4<strong>Server Interface</strong> - Request that the memory manager change current access permission on the specified memory object's data.
5<h3>SYNOPSIS</h3>
6<pre>
7<strong>kern_return_t   memory_object_data_unlock</strong>
8                <strong>(memory_object_t</strong>                  <var>memory_object</var>,
9                 <strong>memory_object_control_t</strong>         <var>memory_control</var>,
10                 <strong>vm_offset_t</strong>                             <var>offset</var>,
11                 <strong>vm_size_t</strong>                               <var>length</var>,
12                 <strong>vm_prot_t</strong>                       <var>desired_access</var><strong>);</strong>
13
14
15<strong>kern_return_t   seqnos_memory_object_data_unlock</strong>
16                <strong>(memory_object_t</strong>                  <var>memory_object</var>,
17                 <strong>mach_port_seqno_t</strong>                        <var>seqno</var>,
18                 <strong>memory_object_control_t</strong>         <var>memory_control</var>,
19                 <strong>vm_offset_t</strong>                             <var>offset</var>,
20                 <strong>vm_size_t</strong>                               <var>length</var>,
21                 <strong>vm_prot_t</strong>                       <var>desired_access</var><strong>);</strong>
22</pre>
23<h3>PARAMETERS</h3>
24<dl>
25<p>
26<dt> <var>memory_object</var> 
27<dd>
28[in abstract-memory-object (receive) right]
29The abstract memory
30object port that represents the memory object data.
31<p>
32<dt> <var>seqno</var> 
33<dd>
34[in scalar]
35The sequence number of this message relative to the abstract 
36memory object port.
37<p>
38<dt> <var>memory_control</var> 
39<dd>
40[in memory-cache-control send right]
41The memory cache control port 
42to be used for a response by the memory manager.  If the memory
43object has been supplied to more than one kernel, this parameter
44identifies the kernel that is making the call.
45<p>
46<dt> <var>offset</var> 
47<dd>
48[in scalar]
49The offset within the memory object.
50<p>
51<dt> <var>length</var> 
52<dd>
53[in scalar]
54The number of bytes to which the access applies, starting at 
55<var>offset</var>.  The number converts to an integral number of memory object 
56pages.
57<p>
58<dt> <var>desired_access</var> 
59<dd>
60[in scalar]
61The memory access modes requested for the cached data. 
62Possible values are obtained by or'ing together the following values:
63<dl>
64<p>
65<dt> <strong>VM_PROT_READ</strong>
66<dd>
67Allows read access.
68<p>
69<dt> <strong>VM_PROT_WRITE</strong>
70<dd>
71Allows write access.
72<p>
73<dt> <strong>VM_PROT_EXECUTE</strong>
74<dd>
75Allows execute access.
76</dl>
77</dl>
78<h3>DESCRIPTION</h3>
79<p>
80A <strong>memory_object_data_unlock</strong> function is called as the
81result of a kernel
82message requesting the memory manager to permit at least the
83desired access to the 
84specified data cached by the kernel.  The memory manager is expected
85to use the 
86<strong>memory_object_lock_request</strong> call in response.
87<h3>RETURN VALUES</h3>
88<p>
89Only generic errors apply.
90<h3>RELATED INFORMATION</h3>
91<p>
92Functions:
93<a href="MO_lock_completed.html"><strong>memory_object_lock_completed</strong></a>,
94<a href="memory_object_lock_request.html"><strong>memory_object_lock_request</strong></a>,
95<a href="memory_object_server.html"><strong>memory_object_server</strong></a>,
96<a href="SMO_server.html"><strong>seqnos_memory_object_server</strong></a>.
97