xref: /xnu-10002.61.3/osfmk/man/memory_object_data_error.html (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1*0f4c859eSApple OSS Distributions<h2>memory_object_data_error</h2>
2*0f4c859eSApple OSS Distributions<hr>
3*0f4c859eSApple OSS Distributions<p>
4*0f4c859eSApple OSS Distributions<strong>Function</strong> - An error prevents the supply of previously requested data.
5*0f4c859eSApple OSS Distributions<h3>SYNOPSIS</h3>
6*0f4c859eSApple OSS Distributions<pre>
7*0f4c859eSApple OSS Distributions<strong>kern_return_t   memory_object_data_error</strong>
8*0f4c859eSApple OSS Distributions                <strong>(memory_object_control_t</strong>         <var>memory_control</var>,
9*0f4c859eSApple OSS Distributions                 <strong>vm_offset_t</strong>                             <var>offset</var>,
10*0f4c859eSApple OSS Distributions                 <strong>vm_size_t</strong>                                 <var>size</var>,
11*0f4c859eSApple OSS Distributions                 <strong>kern_return_t</strong>                           <var>reason</var><strong>);</strong>
12*0f4c859eSApple OSS Distributions</pre>
13*0f4c859eSApple OSS Distributions<h3>PARAMETERS</h3>
14*0f4c859eSApple OSS Distributions<dl>
15*0f4c859eSApple OSS Distributions<p>
16*0f4c859eSApple OSS Distributions<dt> <var>memory_control</var>
17*0f4c859eSApple OSS Distributions<dd>
18*0f4c859eSApple OSS Distributions[in memory-cache-control send right]
19*0f4c859eSApple OSS DistributionsThe memory cache control port
20*0f4c859eSApple OSS Distributionsto be used by the memory manager for cache management requests.
21*0f4c859eSApple OSS DistributionsThis port is provided by the kernel in a <strong>memory_object_create</strong> call.
22*0f4c859eSApple OSS Distributions<p>
23*0f4c859eSApple OSS Distributions<dt> <var>offset</var>
24*0f4c859eSApple OSS Distributions<dd>
25*0f4c859eSApple OSS Distributions[in scalar]
26*0f4c859eSApple OSS DistributionsThe offset within the memory object, in bytes.
27*0f4c859eSApple OSS Distributions<p>
28*0f4c859eSApple OSS Distributions<dt> <var>size</var>
29*0f4c859eSApple OSS Distributions<dd>
30*0f4c859eSApple OSS Distributions[in scalar]
31*0f4c859eSApple OSS DistributionsThe number of bytes of data (starting at <var>offset</var>).  The number
32*0f4c859eSApple OSS Distributionsmust convert to an integral number of memory object pages.
33*0f4c859eSApple OSS Distributions<p>
34*0f4c859eSApple OSS Distributions<dt> <var>reason</var>
35*0f4c859eSApple OSS Distributions<dd>
36*0f4c859eSApple OSS Distributions[in scalar]
37*0f4c859eSApple OSS DistributionsReason for the error.
38*0f4c859eSApple OSS Distributions</dl>
39*0f4c859eSApple OSS Distributions<h3>DESCRIPTION</h3>
40*0f4c859eSApple OSS Distributions<p>
41*0f4c859eSApple OSS DistributionsThe <strong>memory_object_data_error</strong> function indicates that
42*0f4c859eSApple OSS Distributionsthe memory manager
43*0f4c859eSApple OSS Distributionscannot provide the kernel with the data requested for the given region,
44*0f4c859eSApple OSS Distributionsspecifying a reason for the error.
45*0f4c859eSApple OSS Distributions<p>
46*0f4c859eSApple OSS DistributionsWhen the kernel issues a <strong>memory_object_data_request</strong> call, the memory
47*0f4c859eSApple OSS Distributionsmanager can respond with a <strong>memory_object_data_error</strong>
48*0f4c859eSApple OSS Distributionscall to indicate that the
49*0f4c859eSApple OSS Distributionspage cannot be retrieved, and that a memory failure exception should be raised
50*0f4c859eSApple OSS Distributionsin any client threads that are waiting for the page.  Clients
51*0f4c859eSApple OSS Distributionsare permitted to catch
52*0f4c859eSApple OSS Distributionsthese exceptions and retry their page faults.  As a result, this
53*0f4c859eSApple OSS Distributionscall can be used to
54*0f4c859eSApple OSS Distributionsreport transient errors as well as permanent ones.  A memory manager can use
55*0f4c859eSApple OSS Distributionsthis call for both hardware errors (for example, disk failures) and software
56*0f4c859eSApple OSS Distributionserrors (for example, accessing data that does not exist or is protected).
57*0f4c859eSApple OSS Distributions<h3>NOTES</h3>
58*0f4c859eSApple OSS Distributions<p>
59*0f4c859eSApple OSS DistributionsIf reason has a system code of <var>err_kern</var>, the kernel will substitute
60*0f4c859eSApple OSS Distributionsan error value
61*0f4c859eSApple OSS Distributionsof <strong>KERN_MEMORY_ERROR</strong>.
62*0f4c859eSApple OSS Distributions<h3>RETURN VALUES</h3>
63*0f4c859eSApple OSS Distributions<p>
64*0f4c859eSApple OSS DistributionsOnly generic errors apply.
65*0f4c859eSApple OSS Distributions<h3>RELATED INFORMATION</h3>
66*0f4c859eSApple OSS Distributions<p>
67*0f4c859eSApple OSS DistributionsFunctions:
68*0f4c859eSApple OSS Distributions<a href="memory_object_data_request.html"><strong>memory_object_data_request</strong></a>,
69*0f4c859eSApple OSS Distributions<a href="memory_object_data_supply.html"><strong>memory_object_data_supply</strong></a>,
70*0f4c859eSApple OSS Distributions<a href="MO_data_unavailable.html"><strong>memory_object_data_unavailable</strong></a>.
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