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1.1 root 1: /*
2: * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
7: * Reserved. This file contains Original Code and/or Modifications of
8: * Original Code as defined in and that are subject to the Apple Public
9: * Source License Version 1.1 (the "License"). You may not use this file
10: * except in compliance with the License. Please obtain a copy of the
11: * License at http://www.apple.com/publicsource and read it before using
12: * this file.
13: *
14: * The Original Code and all software distributed under the License are
15: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
19: * License for the specific language governing rights and limitations
20: * under the License.
21: *
22: * @APPLE_LICENSE_HEADER_END@
23: */
24:
25: /*
26: * Mach Operating System
27: * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
28: * All Rights Reserved.
29: *
30: * Permission to use, copy, modify and distribute this software and its
31: * documentation is hereby granted, provided that both the copyright
32: * notice and this permission notice appear in all copies of the
33: * software, derivative works or modified versions, and any portions
34: * thereof, and that both notices appear in supporting documentation.
35: *
36: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
37: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
38: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
39: *
40: * Carnegie Mellon requests users of this software to return to
41: *
42: * Software Distribution Coordinator or [email protected]
43: * School of Computer Science
44: * Carnegie Mellon University
45: * Pittsburgh PA 15213-3890
46: *
47: * any improvements or extensions that they make and grant Carnegie Mellon
48: * the rights to redistribute these changes.
49: */
50: /*
51: * File: sched.h
52: * Author: Avadis Tevanian, Jr.
53: * Date: 1985
54: *
55: * Header file for scheduler.
56: *
57: */
58:
59: #ifndef _KERN_SCHED_H_
60: #define _KERN_SCHED_H_
61:
62: #ifdef KERNEL_BUILD
63: #include <cpus.h>
64: #include <mach_fixpri.h>
65: #include <simple_clock.h>
66: #include <stat_time.h>
67: #else /* KERNEL_BUILD */
68: #include <mach/features.h>
69: #endif /* KERNEL_BUILD */
70:
71: #include <kern/queue.h>
72: #include <kern/lock.h>
73: #include <kern/macro_help.h>
74:
75: #if STAT_TIME
76:
77: /*
78: * Statistical timing uses microseconds as timer units. 18 bit shift
79: * yields priorities. PRI_SHIFT_2 isn't needed.
80: */
81: #define PRI_SHIFT 18
82:
83: #else /* STAT_TIME */
84:
85: /*
86: * Otherwise machine provides shift(s) based on time units it uses.
87: */
88: #include <machine/sched_param.h>
89:
90: #endif /* STAT_TIME */
91: #define NRQS 32 /* 32 run queues per cpu */
92:
93: struct run_queue {
94: queue_head_t runq[NRQS]; /* one for each priority */
95: decl_simple_lock_data(, lock) /* one lock for all queues */
96: int high; /* high queue value */
97: int count; /* count of threads runable */
98: };
99:
100: typedef struct run_queue *run_queue_t;
101: #define RUN_QUEUE_NULL ((run_queue_t) 0)
102:
103: #define csw_needed(thread, processor) ( \
104: ((thread)->state & TH_SUSP) || \
105: ((processor)->runq.count > 0) || \
106: (((processor)->processor_set->runq.count > 0) && \
107: ((processor)->first_quantum? \
108: (processor)->processor_set->runq.high > (thread)->sched_pri : \
109: (processor)->processor_set->runq.high >= (thread)->sched_pri)))
110:
111: /*
112: * Scheduler routines.
113: */
114:
115: extern struct run_queue *rem_runq();
116: extern struct thread *choose_thread();
117: extern queue_head_t action_queue; /* assign/shutdown queue */
118: decl_simple_lock_data(extern,action_lock);
119:
120: extern int min_quantum; /* defines max context switch rate */
121:
122: /*
123: * Default base priorities for threads.
124: */
125: #define BASEPRI_SYSTEM 24
126: #define MAXPRI_USER 18
127: #define BASEPRI_USER 10
128:
129: /*
130: * Macro to check for invalid priorities.
131: */
132:
133: #define invalid_pri(pri) (((pri) < 0) || ((pri) >= NRQS))
134:
135: /*
136: * Shift structures for holding update shifts. Actual computation
137: * is usage = (usage >> shift1) +/- (usage >> abs(shift2)) where the
138: * +/- is determined by the sign of shift 2.
139: */
140: struct shift {
141: int shift1;
142: int shift2;
143: };
144:
145: typedef struct shift *shift_t, shift_data_t;
146:
147: /*
148: * sched_tick increments once a second. Used to age priorities.
149: */
150:
151: extern unsigned sched_tick;
152:
153: #define SCHED_SCALE 128
154: #define SCHED_SHIFT 7
155:
156: /*
157: * thread_timer_delta macro takes care of both thread timers.
158: */
159:
160: #define thread_timer_delta(thread) \
161: MACRO_BEGIN \
162: register unsigned delta; \
163: \
164: delta = 0; \
165: TIMER_DELTA((thread)->system_timer, \
166: (thread)->system_timer_save, delta); \
167: TIMER_DELTA((thread)->user_timer, \
168: (thread)->user_timer_save, delta); \
169: (thread)->cpu_delta += delta; \
170: (thread)->sched_delta += delta * \
171: (thread)->processor_set->sched_load; \
172: MACRO_END
173:
174: #if SIMPLE_CLOCK
175: /*
176: * sched_usec is an exponential average of number of microseconds
177: * in a second for clock drift compensation.
178: */
179:
180: extern int sched_usec;
181: #endif /* SIMPLE_CLOCK */
182:
183: #endif /* _KERN_SCHED_H_ */
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