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 * @OSF_COPYRIGHT@
30 */
31 /*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or [email protected]
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56 /*
57 */
58
59 #ifndef _KERN_TIMER_H_
60 #define _KERN_TIMER_H_
61
62 #include <kern/kern_types.h>
63
64 /*
65 * Definitions for high resolution timers.
66 */
67
68 #if __LP64__
69 #define TIMER_ALIGNMENT
70 #else
71 #define TIMER_ALIGNMENT __attribute__((packed, aligned(4)))
72 #endif
73
74 struct timer {
75 uint64_t tstamp;
76 #if defined(__LP64__)
77 uint64_t all_bits;
78 #else /* defined(__LP64__) */
79 /* A check word on the high portion allows atomic updates. */
80 uint32_t low_bits;
81 uint32_t high_bits;
82 uint32_t high_bits_check;
83 #endif /* !defined(__LP64__) */
84 } TIMER_ALIGNMENT;
85
86 typedef struct timer timer_data_t, *timer_t;
87
88 /*
89 * Initialize the `timer`.
90 */
91 void timer_init(timer_t timer);
92
93 /*
94 * Start the `timer` at time `tstamp`.
95 */
96 void timer_start(timer_t timer, uint64_t tstamp);
97
98 /*
99 * Stop the `timer` and update it with time `tstamp`.
100 */
101 void timer_stop(timer_t timer, uint64_t tstamp);
102
103 /*
104 * Update the `timer` at time `tstamp`, leaving it running.
105 */
106 void timer_update(timer_t timer, uint64_t tstamp);
107
108 /*
109 * Read the accumulated time of `timer`.
110 */
111 #if defined(__LP64__)
112 static inline
113 uint64_t
timer_grab(timer_t timer)114 timer_grab(timer_t timer)
115 {
116 return timer->all_bits;
117 }
118 #else /* defined(__LP64__) */
119 uint64_t timer_grab(timer_t timer);
120 #endif /* !defined(__LP64__) */
121
122 #endif /* _KERN_TIMER_H_ */
123