osfmk/man/mach_port_set_seqno.html

   1 <h2>mach_port_set_seqno</h2>
   2 <hr>
   3 <p>
   4 <strong>Function</strong> - Change the current value of the target port's sequence number.
   5 <h3>SYNOPSIS</h3>
   6 <pre>
   7 <strong>kern_return_t   mach_port_set_seqno</strong>
   8                 <strong>(ipc_space_t</strong>                               <var>task</var>,
   9                  <strong>mach_port_name_t</strong>                          <var>name</var>,
  10                  <strong>mach_port_seqno_t</strong>                        <var>seqno</var><strong>);</strong>
  11 </pre>
  12 <h3>PARAMETERS</h3>
  13 <dl>
  14 <p>
  15 <dt> <var>task</var>
  16 <dd>
  17 [in task send right]
  18 The task owning the receive right.
  19 <p>
  20 <dt> <var>name</var>
  21 <dd>
  22 [in scalar]
  23 <var>task</var>'s name for the receive right.
  24 <p>
  25 <dt> <var>seqno</var>
  26 <dd>
  27 [in scalar]
  28 The sequence number that the next message received from
  29 the port will have.
  30 </dl>
  31 <h3>DESCRIPTION</h3>
  32 <p>
  33 The <strong>mach_port_set_seqno</strong> function changes the sequence
  34 number of <var>task</var>'s
  35 receive right named <var>name</var>.
  36 <p>
  37 (Each port is associated with a sequence number attribute that can be
  38 used to track the order in which messages sent to the port are received.
  39 A port's sequence number is initially set to zero and is incremented each
  40 time a message is received from the port.  A port's sequence number is
  41 automatically reset to zero each time the port's receive right migrates.)
  42 <h3>NOTES</h3>
  43 <p>
  44 This interface is machine word length specific because of the port name
  45 parameter.
  46 <h3>RETURN VALUES</h3>
  47 <dl>
  48 <p>
  49 <dt> <strong>KERN_INVALID_NAME</strong>
  50 <dd>
  51 <var>name</var> did not denote a right.
  52 <p>
  53 <dt> <strong>KERN_INVALID_RIGHT</strong>
  54 <dd>
  55 <var>name</var> denoted a right, but not a receive right.
  56 </dl>
  57 <h3>RELATED INFORMATION</h3>
  58 <p>
  59 Functions:
  60 <a href="mach_port_get_attributes.html"><strong>mach_port_get_attributes</strong></a>.