1/*
2 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#ifndef _MACH_THREAD_POLICY_H_
30#define _MACH_THREAD_POLICY_H_
31
32#include <mach/mach_types.h>
33
34/*
35 * These are the calls for accessing the policy parameters
36 * of a particular thread.
37 *
38 * The extra 'get_default' parameter to the second call is
39 * IN/OUT as follows:
40 * 1) if asserted on the way in it indicates that the default
41 * values should be returned, not the ones currently set, in
42 * this case 'get_default' will always be asserted on return;
43 * 2) if unasserted on the way in, the current settings are
44 * desired and if still unasserted on return, then the info
45 * returned reflects the current settings, otherwise if
46 * 'get_default' returns asserted, it means that there are no
47 * current settings due to other parameters taking precedence,
48 * and the default ones are being returned instead.
49 */
50
51typedef natural_t	thread_policy_flavor_t;
52typedef integer_t	*thread_policy_t;
53
54/*
55kern_return_t	thread_policy_set(
56					thread_t					thread,
57					thread_policy_flavor_t		flavor,
58					thread_policy_t				policy_info,
59					mach_msg_type_number_t		count);
60
61kern_return_t	thread_policy_get(
62					thread_t					thread,
63					thread_policy_flavor_t		flavor,
64					thread_policy_t				policy_info,
65					mach_msg_type_number_t		*count,
66					boolean_t					*get_default);
67*/
68
69/*
70 * Defined flavors.
71 */
72/*
73 * THREAD_STANDARD_POLICY:
74 *
75 * This is the standard (fair) scheduling mode, assigned to new
76 * threads.  The thread will be given processor time in a manner
77 * which apportions approximately equal share to long running
78 * computations.
79 *
80 * Parameters:
81 *	[none]
82 */
83
84#define THREAD_STANDARD_POLICY			1
85
86struct thread_standard_policy {
87	natural_t		no_data;
88};
89
90typedef struct thread_standard_policy	thread_standard_policy_data_t;
91typedef struct thread_standard_policy	*thread_standard_policy_t;
92
93#define THREAD_STANDARD_POLICY_COUNT	0
94
95/*
96 * THREAD_EXTENDED_POLICY:
97 *
98 * Extended form of THREAD_STANDARD_POLICY, which supplies a
99 * hint indicating whether this is a long running computation.
100 *
101 * Parameters:
102 *
103 * timeshare: TRUE (the default) results in identical scheduling
104 * behavior as THREAD_STANDARD_POLICY.
105 */
106
107#define THREAD_EXTENDED_POLICY			1
108
109struct thread_extended_policy {
110	boolean_t		timeshare;
111};
112
113typedef struct thread_extended_policy	thread_extended_policy_data_t;
114typedef struct thread_extended_policy	*thread_extended_policy_t;
115
116#define THREAD_EXTENDED_POLICY_COUNT	((mach_msg_type_number_t) \
117	(sizeof (thread_extended_policy_data_t) / sizeof (integer_t)))
118
119/*
120 * THREAD_TIME_CONSTRAINT_POLICY:
121 *
122 * This scheduling mode is for threads which have real time
123 * constraints on their execution.
124 *
125 * Parameters:
126 *
127 * period: This is the nominal amount of time between separate
128 * processing arrivals, specified in absolute time units.  A
129 * value of 0 indicates that there is no inherent periodicity in
130 * the computation.
131 *
132 * computation: This is the nominal amount of computation
133 * time needed during a separate processing arrival, specified
134 * in absolute time units.
135 *
136 * constraint: This is the maximum amount of real time that
137 * may elapse from the start of a separate processing arrival
138 * to the end of computation for logically correct functioning,
139 * specified in absolute time units.  Must be (>= computation).
140 * Note that latency = (constraint - computation).
141 *
142 * preemptible: This indicates that the computation may be
143 * interrupted, subject to the constraint specified above.
144 */
145
146#define THREAD_TIME_CONSTRAINT_POLICY	2
147
148struct thread_time_constraint_policy {
149	uint32_t		period;
150	uint32_t		computation;
151	uint32_t		constraint;
152	boolean_t		preemptible;
153};
154
155typedef struct thread_time_constraint_policy	\
156									thread_time_constraint_policy_data_t;
157typedef struct thread_time_constraint_policy	\
158									*thread_time_constraint_policy_t;
159
160#define THREAD_TIME_CONSTRAINT_POLICY_COUNT	((mach_msg_type_number_t) \
161	(sizeof (thread_time_constraint_policy_data_t) / sizeof (integer_t)))
162
163/*
164 * THREAD_PRECEDENCE_POLICY:
165 *
166 * This may be used to indicate the relative value of the
167 * computation compared to the other threads in the task.
168 *
169 * Parameters:
170 *
171 * importance: The importance is specified as a signed value.
172 */
173
174#define THREAD_PRECEDENCE_POLICY		3
175
176struct thread_precedence_policy {
177	integer_t		importance;
178};
179
180typedef struct thread_precedence_policy		thread_precedence_policy_data_t;
181typedef struct thread_precedence_policy		*thread_precedence_policy_t;
182
183#define THREAD_PRECEDENCE_POLICY_COUNT	((mach_msg_type_number_t) \
184	(sizeof (thread_precedence_policy_data_t) / sizeof (integer_t)))
185
186/*
187 * THREAD_AFFINITY_POLICY:
188 *
189 * This policy is experimental.
190 * This may be used to express affinity relationships
191 * between threads in the task. Threads with the same affinity tag will
192 * be scheduled to share an L2 cache if possible. That is, affinity tags
193 * are a hint to the scheduler for thread placement.
194 *
195 * The namespace of affinity tags is generally local to one task. However,
196 * a child task created after the assignment of affinity tags by its parent
197 * will share that namespace. In particular, a family of forked processes
198 * may be created with a shared affinity namespace.
199 *
200 * Parameters:
201 * tag: The affinity set identifier.
202 */
203
204#define THREAD_AFFINITY_POLICY		4
205
206struct thread_affinity_policy {
207	integer_t	affinity_tag;
208};
209
210#define THREAD_AFFINITY_TAG_NULL		0
211
212typedef struct thread_affinity_policy		thread_affinity_policy_data_t;
213typedef struct thread_affinity_policy		*thread_affinity_policy_t;
214
215#define THREAD_AFFINITY_POLICY_COUNT	((mach_msg_type_number_t) \
216	(sizeof (thread_affinity_policy_data_t) / sizeof (integer_t)))
217
218/*
219 * THREAD_BACKGROUND_POLICY:
220 */
221
222#define THREAD_BACKGROUND_POLICY	5
223
224struct thread_background_policy {
225	integer_t	priority;
226};
227
228typedef struct thread_background_policy		thread_background_policy_data_t;
229typedef struct thread_background_policy 	*thread_background_policy_t;
230
231#define THREAD_BACKGROUND_POLICY_COUNT	((mach_msg_type_number_t) \
232	(sizeof (thread_background_policy_data_t) / sizeof (integer_t)))
233
234
235
236#ifdef PRIVATE
237
238/*
239 * THREAD_POLICY_STATE:
240 */
241#define THREAD_POLICY_STATE		6
242
243struct thread_policy_state {
244	integer_t requested;
245	integer_t effective;
246	integer_t pending;
247	integer_t reserved[13];
248};
249
250typedef struct thread_policy_state		thread_policy_state_data_t;
251typedef struct thread_policy_state		*thread_policy_state_t;
252
253#define THREAD_POLICY_STATE_COUNT	((mach_msg_type_number_t) \
254	(sizeof (thread_policy_state_data_t) / sizeof (integer_t)))
255
256#endif /* PRIVATE */
257
258#endif	/* _MACH_THREAD_POLICY_H_ */
259