[apple/xnu.git] / osfmk / man / ledger_get_remote.html

<h2>ledger_get_remote</h2>\r<hr>\r<p>\r<strong>Function</strong> - Return send right to specified host's remote ledger port.\r<h3>SYNOPSIS</h3>\r<pre>\r<strong>kern_return_t   ledger_get_remote</strong>\r                <strong>(ledger_port_t</strong>                           <var>ledger</var>,\r                 <strong>host_t</strong>                               <var>host_name</var>,\r                 <strong>ledger</strong>                            <var>service_port</var><strong>);</strong>\r\r\r<strong>kern_return_t   ledger_return_remote</strong>\r                <strong>(ledger_port_t</strong>                           <var>ledger</var>,\r                 <strong>host_t</strong>                               <var>host_name</var>,\r                 <strong>ledger</strong>                            <var>service_port</var><strong>);</strong>\r</pre>\r<h3>PARAMETERS</h3>\r<dl>\r<p>\r<dt> <var>ledger</var> \r<dd>\r[in ledger send right]\rThe ledger whose service port is desired.\r<p>\r<dt> <var>host_name</var> \r<dd>\r[in host-name send right]\rThe name for the host requesting the service \rport.\r<p>\r<dt> <var>service_port</var> \r<dd>\r[out ledger-service send right]\rThe ledger service port.\r</dl>\r<h3>DESCRIPTION</h3>\r<p>\rThe <strong>ledger_get_remote</strong> function returns the remote ledger\rservice port for the \rledger\r<h3>NOTES</h3>\r<p>\rThis interface is not implemented in OSF/1 R1.3.\r<p>\rThis mechanism supports distributed resource ledgers in the following way:\r<dl>\r<dd>\rWith <strong>ledger_set_remote</strong>, a ledger is assigned a remote\rledger service port.\r<dd>\rThis ledger is used as the ledger for a create operation.  \rIf the ledger is local to the target kernel, all is fine.\r<dd>\rFor a non-local creation, the target kernel sees that the supplied\rledger is not \ra local ledger.  The kernel sends a <strong>ledger_get_remote</strong> message to it,\rincluding the host name.\r<dd>\rThe (remote) ledger receives this message, ignores the host name and returns \rthe remote ledger service port.\r<dd>\rAssuming that the remote ledger service port is not a local ledger, the kernel \rsends a <strong>ledger_get_remote</strong> message to this service port.\r<dd>\rA server receives this request (with the <strong>ledger_return_remote</strong>\rserver interface) \rand uses the identity of the service port as well as the host name of the \rtarget kernel to locate or create a suitable ledger on that kernel.\r<dd>\rThe port for a ledger on the target kernel is sent to that kernel and used.\r</dl>\r<h3>RETURN VALUES</h3>\r<p>\rOnly generic errors apply.\r<h3>RELATED INFORMATION</h3>\r<p>\rFunctions:\r<a href="ledger_create.html"><strong>ledger_create</strong></a>,\r<a href="ledger_set_remote.html"><strong>ledger_set_remote</strong></a>.\r