xref: /xnu-10063.121.3/osfmk/man/thread_activation_create.html (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa)
1*2c2f96dcSApple OSS Distributions<h2>thread_activation_create</h2>
2*2c2f96dcSApple OSS Distributions<hr>
3*2c2f96dcSApple OSS Distributions<p>
4*2c2f96dcSApple OSS Distributions<strong>Function</strong> - Create a thread activation.
5*2c2f96dcSApple OSS Distributions<h3>SYNOPSIS</h3>
6*2c2f96dcSApple OSS Distributions<pre>
7*2c2f96dcSApple OSS Distributions<strong>kern_return_t   thread_activation_create</strong>
8*2c2f96dcSApple OSS Distributions                <strong>(task_t</strong>                                    <var>task</var>,
9*2c2f96dcSApple OSS Distributions                 <strong>mach_port_name_t</strong>                      <var>RPC_port</var>,
10*2c2f96dcSApple OSS Distributions                 <strong>vm_offset_t</strong>                         <var>user_stack</var>,
11*2c2f96dcSApple OSS Distributions                 <strong>vm_size_t</strong>                           <var>stack_size</var>,
12*2c2f96dcSApple OSS Distributions                 <strong>thread_act_t</strong>                      <var>thread_act_t</var><strong>);</strong>
13*2c2f96dcSApple OSS Distributions</pre>
14*2c2f96dcSApple OSS Distributions<h3>PARAMETERS</h3>
15*2c2f96dcSApple OSS Distributions<dl>
16*2c2f96dcSApple OSS Distributions<p>
17*2c2f96dcSApple OSS Distributions<dt> <var>task</var>
18*2c2f96dcSApple OSS Distributions<dd>
19*2c2f96dcSApple OSS Distributions[in task send right] The port for the task that is to contain the new
20*2c2f96dcSApple OSS Distributionsthread activation.
21*2c2f96dcSApple OSS Distributions<p>
22*2c2f96dcSApple OSS Distributions<dt> <var>RPC_port</var>
23*2c2f96dcSApple OSS Distributions<dd>
24*2c2f96dcSApple OSS Distributions[in receive right] A receive right held by the task, or a port set in the
25*2c2f96dcSApple OSS Distributionstask.
26*2c2f96dcSApple OSS Distributions<p>
27*2c2f96dcSApple OSS Distributions<dt> <var>user_stack</var>
28*2c2f96dcSApple OSS Distributions<dd>
29*2c2f96dcSApple OSS Distributions[in scalar] The virtual address in the task to be used as the starting ad-
30*2c2f96dcSApple OSS Distributionsdress of the user-level stack.
31*2c2f96dcSApple OSS Distributions<p>
32*2c2f96dcSApple OSS Distributions<dt> <var>new_act</var>
33*2c2f96dcSApple OSS Distributions<dd>
34*2c2f96dcSApple OSS Distributions[out thread send right] The kernel-assigned name for the new thread ac-
35*2c2f96dcSApple OSS Distributionstivation.
36*2c2f96dcSApple OSS Distributions</dl>
37*2c2f96dcSApple OSS Distributions<h3>DESCRIPTION</h3>
38*2c2f96dcSApple OSS Distributions<p>
39*2c2f96dcSApple OSS DistributionsThe thread_activation_create function creates a thread activation, or
40*2c2f96dcSApple OSS Distributions"empty thread", into which a client thread shuttle can migrate during
41*2c2f96dcSApple OSS DistributionsRPC.  The RPC_port must name ei- ther a receive right held by the
42*2c2f96dcSApple OSS Distributionstask, or a port set in the task.  The new thread activation will be
43*2c2f96dcSApple OSS Distributionsadded to a pool of activations attached to this port (or port set).
44*2c2f96dcSApple OSS DistributionsIncoming RPC's targeted at the port (or one of the ports in the set)
45*2c2f96dcSApple OSS Distributionscan use any of the activations in the pool.  That is, the client
46*2c2f96dcSApple OSS Distributionsthread shuttle will migrate into the specified server task, take one
47*2c2f96dcSApple OSS Distributionsof the thread activations out of the pool, and join up with it for the
48*2c2f96dcSApple OSS Distributionsduration of the RPC.  The shuttle will migrate back to the original
49*2c2f96dcSApple OSS Distributionsclient activation at the end of the RPC.  If no thread activations are
50*2c2f96dcSApple OSS Distributionsin the pool, RPC will be blocked until one is created in the pool, or
51*2c2f96dcSApple OSS Distributionsan existing one finishes its RPC and returns to the pool.
52*2c2f96dcSApple OSS DistributionsThe new thread activation will begin each RPC using the stack pointer
53*2c2f96dcSApple OSS Distributionsspecified by user_stack.  The kernel neither knows nor cares how big
54*2c2f96dcSApple OSS Distributionsthe specified stack is.
55*2c2f96dcSApple OSS DistributionsWhen a short-circuited RPC (or mach_rpc) is invoked on a port created
56*2c2f96dcSApple OSS Distributionswith mach_port_allocate_subsystem, the RPC will begin execution in the
57*2c2f96dcSApple OSS Distributionssubsystem server at the work function address specified by the port
58*2c2f96dcSApple OSS Distributionsand routine number and looked up in the associated subsystem data.
59*2c2f96dcSApple OSS Distributions<h3>NOTES</h3>
60*2c2f96dcSApple OSS Distributions<p>
61*2c2f96dcSApple OSS DistributionsThe following calls targeted at a thread_act port may _not_ be called
62*2c2f96dcSApple OSS Distributionson an empty thread_act (and will return KERN_INVALID_ARGUMENT if
63*2c2f96dcSApple OSS Distributionsthey are called with one):
64*2c2f96dcSApple OSS Distributionsthread_abort
65*2c2f96dcSApple OSS Distributionsthread_abort_safely
66*2c2f96dcSApple OSS Distributionsthread_depress_abort
67*2c2f96dcSApple OSS Distributionsthread_info
68*2c2f96dcSApple OSS Distributionsthread_wire
69*2c2f96dcSApple OSS DistributionsIn addition, if thread_switch is called with an empty thread_act as
70*2c2f96dcSApple OSS Distributionsits first argument, the argument will be ignored (i.e., the function
71*2c2f96dcSApple OSS Distributionswill behave as if a zero-valued argument had been given).
72*2c2f96dcSApple OSS Distributions<h3>RETURN VALUES</h3>
73*2c2f96dcSApple OSS Distributions<p>
74*2c2f96dcSApple OSS DistributionsOnly generic errors apply.
75*2c2f96dcSApple OSS Distributions<h3>RELATED INFORMATION</h3>
76*2c2f96dcSApple OSS Distributions<p>
77*2c2f96dcSApple OSS DistributionsFunctions:
78*2c2f96dcSApple OSS Distributions<a href="task_create.html"><strong>task_create</strong></a>,
79*2c2f96dcSApple OSS Distributions<a href="MP_allocate_subsystem.html"><strong>mach_port_allocate_subsystem</strong></a>,
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