1/*
2 * Copyright (c) 2019 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/*
30 *
31 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
32 *
33 * HISTORY
34 *
35 * 2001-01-18 gvdl Made the primary queue pointer public, to be used when
36 * Ownership is clear.
37 * 11/13/2000 CJS Created IOCommand class and implementation
38 *
39 */
40
41/*!
42 * @header IOCommand
43 * @abstract
44 * This header contains the IOCommand class definition.
45 */
46
47#ifndef _IOKIT_IO_COMMAND_H_
48#define _IOKIT_IO_COMMAND_H_
49
50/*
51 * Kernel
52 */
53
54#if defined(KERNEL) && defined(__cplusplus)
55
56#include <kern/queue.h>
57#include <libkern/c++/OSObject.h>
58
59/*!
60 * @class IOCommand
61 * @abstract
62 * This class is an abstract class which represents an I/O command.
63 * @discussion
64 * This class is an abstract class which represents an I/O command passed
65 * from a device driver to a controller. All controller commands (e.g. IOATACommand)
66 * should inherit from this class.
67 */
68
69class IOCommand : public OSObject
70{
71 OSDeclareDefaultStructors(IOCommand);
72
73public:
74 virtual bool init(void) APPLE_KEXT_OVERRIDE;
75
76/*! @var fCommandChain
77 * 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 */
78 queue_chain_t fCommandChain; /* used to queue commands */
79};
80
81#endif /* defined(KERNEL) && defined(__cplusplus) */
82
83#endif /* _IOKIT_IO_COMMAND_H_ */
84