]> git.saurik.com Git - apple/xnu.git/blob - osfmk/man/ledger_create.html
xnu-1504.3.12.tar.gz
[apple/xnu.git] / osfmk / man / ledger_create.html
1 <h2>ledger_create</h2>
2 <hr>
3 <p>
4 <strong>Function</strong> - Create a subordinate ledger.
5 <h3>SYNOPSIS</h3>
6 <pre>
7 <strong>kern_return_t ledger_create</strong>
8 <strong>(ledger_port_t</strong> <var>parent_ledger</var>,
9 <strong>ledger_port_t</strong> <var>ledger_ledger</var>,
10 <strong>ledger_port_t</strong> <var>child_ledger</var>,
11 <strong>ledger_item_t</strong> <var>transfer</var><strong>);</strong>
12 </pre>
13 <h3>PARAMETERS</h3>
14 <dl>
15 <p>
16 <dt> <var>parent_ledger</var>
17 <dd>
18 [in ledger send right]
19 The parent ledger.
20 <p>
21 <dt> <var>ledger_ledger</var>
22 <dd>
23 [in ledger send right]
24 The wired kernel memory ledger providing the
25 space from which the ledger itself is drawn.
26 <p>
27 <dt> <var>child_ledger</var>
28 <dd>
29 [out ledger send right]
30 The new child ledger, of the same resource type
31 as the parent ledger.
32 <p>
33 <dt> <var>transfer</var>
34 <dd>
35 [in scalar]
36 The resource amount to transfer to the new ledger.
37 </dl>
38 <h3>DESCRIPTION</h3>
39 <p>
40 The <strong>ledger_create</strong> function creates a subordinate ledger.
41 Resource limits can be
42 transferred from the parent ledger. The child ledger itself
43 is accounted against
44 the <var>ledger_ledger</var>. A new ledger inherits the remote service port.
45 <h3>NOTES</h3>
46 <p>
47 This interface is not implemented in OSF/1 R1.3.
48 <p>
49 A ledger limit of <strong>LEDGER_ITEM_INFINITE</strong> allows any amount (even
50 infinity) to be withdrawn. The root ledger has such a limit.
51 <h3>RETURN VALUES</h3>
52 <dl>
53 <p>
54 <dt> <strong>KERN_RESOURCE_SHORTAGE</strong>
55 <dd>
56 Transferring the resources would cause the parent ledger to exceed its
57 limits.
58 <p>
59 <dt> <strong>KERN_INVALID_LEDGER</strong>
60 <dd>
61 <var>ledger_ledger</var> is not a wired kernel memory ledger.
62 </dl>
63 <h3>RELATED INFORMATION</h3>
64 <p>
65 Functions:
66 <a href="ledger_transfer.html"><strong>ledger_transfer</strong></a>,
67 <a href="ledger_terminate.html"><strong>ledger_terminate</strong></a>,
68 <a href="ledger_read.html"><strong>ledger_read</strong></a>,
69 <a href="ledger_set_remote.html"><strong>ledger_set_remote</strong></a>.