xref: /xnu-11215.41.3/osfmk/man/memory_object_data_error.html (revision 33de042d024d46de5ff4e89f2471de6608e37fa4)
1*33de042dSApple OSS Distributions<h2>memory_object_data_error</h2>
2*33de042dSApple OSS Distributions<hr>
3*33de042dSApple OSS Distributions<p>
4*33de042dSApple OSS Distributions<strong>Function</strong> - An error prevents the supply of previously requested data.
5*33de042dSApple OSS Distributions<h3>SYNOPSIS</h3>
6*33de042dSApple OSS Distributions<pre>
7*33de042dSApple OSS Distributions<strong>kern_return_t   memory_object_data_error</strong>
8*33de042dSApple OSS Distributions                <strong>(memory_object_control_t</strong>         <var>memory_control</var>,
9*33de042dSApple OSS Distributions                 <strong>vm_offset_t</strong>                             <var>offset</var>,
10*33de042dSApple OSS Distributions                 <strong>vm_size_t</strong>                                 <var>size</var>,
11*33de042dSApple OSS Distributions                 <strong>kern_return_t</strong>                           <var>reason</var><strong>);</strong>
12*33de042dSApple OSS Distributions</pre>
13*33de042dSApple OSS Distributions<h3>PARAMETERS</h3>
14*33de042dSApple OSS Distributions<dl>
15*33de042dSApple OSS Distributions<p>
16*33de042dSApple OSS Distributions<dt> <var>memory_control</var>
17*33de042dSApple OSS Distributions<dd>
18*33de042dSApple OSS Distributions[in memory-cache-control send right]
19*33de042dSApple OSS DistributionsThe memory cache control port
20*33de042dSApple OSS Distributionsto be used by the memory manager for cache management requests.
21*33de042dSApple OSS DistributionsThis port is provided by the kernel in a <strong>memory_object_create</strong> call.
22*33de042dSApple OSS Distributions<p>
23*33de042dSApple OSS Distributions<dt> <var>offset</var>
24*33de042dSApple OSS Distributions<dd>
25*33de042dSApple OSS Distributions[in scalar]
26*33de042dSApple OSS DistributionsThe offset within the memory object, in bytes.
27*33de042dSApple OSS Distributions<p>
28*33de042dSApple OSS Distributions<dt> <var>size</var>
29*33de042dSApple OSS Distributions<dd>
30*33de042dSApple OSS Distributions[in scalar]
31*33de042dSApple OSS DistributionsThe number of bytes of data (starting at <var>offset</var>).  The number
32*33de042dSApple OSS Distributionsmust convert to an integral number of memory object pages.
33*33de042dSApple OSS Distributions<p>
34*33de042dSApple OSS Distributions<dt> <var>reason</var>
35*33de042dSApple OSS Distributions<dd>
36*33de042dSApple OSS Distributions[in scalar]
37*33de042dSApple OSS DistributionsReason for the error.
38*33de042dSApple OSS Distributions</dl>
39*33de042dSApple OSS Distributions<h3>DESCRIPTION</h3>
40*33de042dSApple OSS Distributions<p>
41*33de042dSApple OSS DistributionsThe <strong>memory_object_data_error</strong> function indicates that
42*33de042dSApple OSS Distributionsthe memory manager
43*33de042dSApple OSS Distributionscannot provide the kernel with the data requested for the given region,
44*33de042dSApple OSS Distributionsspecifying a reason for the error.
45*33de042dSApple OSS Distributions<p>
46*33de042dSApple OSS DistributionsWhen the kernel issues a <strong>memory_object_data_request</strong> call, the memory
47*33de042dSApple OSS Distributionsmanager can respond with a <strong>memory_object_data_error</strong>
48*33de042dSApple OSS Distributionscall to indicate that the
49*33de042dSApple OSS Distributionspage cannot be retrieved, and that a memory failure exception should be raised
50*33de042dSApple OSS Distributionsin any client threads that are waiting for the page.  Clients
51*33de042dSApple OSS Distributionsare permitted to catch
52*33de042dSApple OSS Distributionsthese exceptions and retry their page faults.  As a result, this
53*33de042dSApple OSS Distributionscall can be used to
54*33de042dSApple OSS Distributionsreport transient errors as well as permanent ones.  A memory manager can use
55*33de042dSApple OSS Distributionsthis call for both hardware errors (for example, disk failures) and software
56*33de042dSApple OSS Distributionserrors (for example, accessing data that does not exist or is protected).
57*33de042dSApple OSS Distributions<h3>NOTES</h3>
58*33de042dSApple OSS Distributions<p>
59*33de042dSApple OSS DistributionsIf reason has a system code of <var>err_kern</var>, the kernel will substitute
60*33de042dSApple OSS Distributionsan error value
61*33de042dSApple OSS Distributionsof <strong>KERN_MEMORY_ERROR</strong>.
62*33de042dSApple OSS Distributions<h3>RETURN VALUES</h3>
63*33de042dSApple OSS Distributions<p>
64*33de042dSApple OSS DistributionsOnly generic errors apply.
65*33de042dSApple OSS Distributions<h3>RELATED INFORMATION</h3>
66*33de042dSApple OSS Distributions<p>
67*33de042dSApple OSS DistributionsFunctions:
68*33de042dSApple OSS Distributions<a href="memory_object_data_request.html"><strong>memory_object_data_request</strong></a>,
69*33de042dSApple OSS Distributions<a href="memory_object_data_supply.html"><strong>memory_object_data_supply</strong></a>,
70*33de042dSApple OSS Distributions<a href="MO_data_unavailable.html"><strong>memory_object_data_unavailable</strong></a>.
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