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1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
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6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
1c79356b 11 *
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12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
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19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22
23/*
24 *
25 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
26 *
27 * HISTORY
28 *
29 * 2001-01-18 gvdl Made the primary queue pointer public, to be used when
30 * Ownership is clear.
31 * 11/13/2000 CJS Created IOCommand class and implementation
32 *
33 */
34
35/*!
36 * @header IOCommand
37 * @abstract
38 * This header contains the IOCommand class definition.
39 */
40
41#ifndef _IOKIT_IO_COMMAND_H_
42#define _IOKIT_IO_COMMAND_H_
43
44/*
45 * Kernel
46 */
47
48#if defined(KERNEL) && defined(__cplusplus)
49
50#include <kern/queue.h>
51#include <libkern/c++/OSObject.h>
52
53class IOCommandPool;
54
55/*!
56 * @class IOCommand
57 * @abstract
58 * This class is an abstract class which represents an I/O command.
59 * @discussion
60 * This class is an abstract class which represents an I/O command passed
61 * from a device driver to a controller. All controller commands (e.g. IOATACommand)
62 * should inherit from this class.
63 */
64
65class IOCommand : public OSObject
66{
67 OSDeclareAbstractStructors(IOCommand)
68
69protected:
70 virtual bool init(void);
71
72public:
73/*! @var fCommandChain
74 This variable is used by the current 'owner' to queue the command. During the life cycle of a command it moves through a series of queues. This is the queue pointer for it. Only valid while 'ownership' is clear. For instance a IOCommandPool uses this pointer to maintain its list of free commands. May be manipulated using the kern/queue.h macros */
75 queue_chain_t fCommandChain; /* used to queue commands */
76};
77
78#endif /* defined(KERNEL) && defined(__cplusplus) */
79
80#endif /* _IOKIT_IO_COMMAND_H_ */