source: rtems/cpukit/score/include/rtems/score/corespinlockimpl.h @ c499856

4.115
Last change on this file since c499856 was c499856, checked in by Chris Johns <chrisj@…>, on Mar 20, 2014 at 9:10:47 PM

Change all references of rtems.com to rtems.org.

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File size: 4.1 KB
Line 
1/**
2 * @file
3 *
4 * @brief Inlined Routines Associated with the SuperCore Spinlock
5 *
6 * This include file contains all of the inlined routines associated
7 * with the SuperCore spinlock.
8 */
9
10/*
11 *  COPYRIGHT (c) 1989-2008.
12 *  On-Line Applications Research Corporation (OAR).
13 *
14 *  The license and distribution terms for this file may be
15 *  found in the file LICENSE in this distribution or at
16 *  http://www.rtems.org/license/LICENSE.
17 */
18
19#ifndef _RTEMS_SCORE_CORESPINLOCKIMPL_H
20#define _RTEMS_SCORE_CORESPINLOCKIMPL_H
21
22#include <rtems/score/corespinlock.h>
23#include <rtems/score/watchdog.h>
24
25#ifdef __cplusplus
26extern "C" {
27#endif
28
29/**
30 * @addtogroup ScoreSpinlock
31 */
32/**@{**/
33
34/**
35 *  Core Spinlock handler return statuses.
36 */
37typedef enum {
38  /** This status indicates that the operation completed successfully. */
39  CORE_SPINLOCK_SUCCESSFUL,
40  /** This status indicates that the current thread already holds the spinlock.
41   *  An attempt to relock it will result in deadlock.
42   */
43  CORE_SPINLOCK_HOLDER_RELOCKING,
44  /** This status indicates that the current thread is attempting to unlock a
45   *  spinlock that is held by another thread.
46   */
47  CORE_SPINLOCK_NOT_HOLDER,
48  /** This status indicates that a thread reached the limit of time it
49   *  was willing to wait on the spin lock.
50   */
51  CORE_SPINLOCK_TIMEOUT,
52  /** This status indicates that a thread is currently waiting for this
53   *  spin lock.
54   */
55  CORE_SPINLOCK_IS_BUSY,
56  /** This status indicates that the spinlock is currently locked and thus
57   *  unavailable.
58   */
59  CORE_SPINLOCK_UNAVAILABLE,
60  /** This status indicates that the spinlock is not currently locked and thus
61   *  should not be released.
62   */
63  CORE_SPINLOCK_NOT_LOCKED
64}   CORE_spinlock_Status;
65
66/** This is a shorthand for the last status code. */
67#define CORE_SPINLOCK_STATUS_LAST CORE_SPINLOCK_NOT_LOCKED
68
69/** This indicates the lock is available. */
70#define CORE_SPINLOCK_UNLOCKED 0
71
72/** This indicates the lock is unavailable. */
73#define CORE_SPINLOCK_LOCKED   1
74
75/**
76 *  @brief Initialize the spinlock.
77 *
78 *  This routine initializes the spinlock based on the parameters passed.
79 *
80 *  @param[in] the_spinlock is the spinlock control block to initialize
81 *  @param[in] the_spinlock_attributes define the behavior of this instance
82 */
83void _CORE_spinlock_Initialize(
84  CORE_spinlock_Control       *the_spinlock,
85  CORE_spinlock_Attributes    *the_spinlock_attributes
86);
87
88/**
89 *  @brief Wait for spinlock.
90 *
91 *  This routine wait for the spinlock to be released.  If the spinlock
92 *  is set to automatic and this is the appropriate thread, then it returns
93 *  immediately.  Otherwise, the calling thread is blocked until the spinlock
94 *  is released.
95 *
96 *  @param[in] the_spinlock is the spinlock to wait for
97 *  @param[in] wait is true if willing to wait
98 *  @param[in] timeout is the maximum number of ticks to spin (0 is forever)
99 *
100 * @retval A status is returned which indicates the success or failure of
101 *         this operation.
102 */
103CORE_spinlock_Status _CORE_spinlock_Wait(
104  CORE_spinlock_Control  *the_spinlock,
105  bool                    wait,
106  Watchdog_Interval       timeout
107);
108
109/**
110 * @brief Manually release the spinlock.
111 *
112 *  This routine manually releases the spinlock.  All of the threads waiting
113 *  for the spinlock will be readied.
114 *
115 *  @param[in] the_spinlock is the spinlock to surrender
116 */
117CORE_spinlock_Status _CORE_spinlock_Release(
118  CORE_spinlock_Control *the_spinlock
119);
120
121/**
122 * This method is used to initialize core spinlock attributes.
123 *
124 * @param[in] the_attributes pointer to the attributes to initialize.
125 */
126RTEMS_INLINE_ROUTINE void _CORE_spinlock_Initialize_attributes(
127  CORE_spinlock_Attributes *the_attributes
128)
129{
130  the_attributes->XXX = 0;
131}
132
133/**
134 * This method is used to determine if the spinlock is available or not.
135 *
136 * @param[in] the_spinlock will be checked
137 *
138 * @return This method will return true if the spinlock is busy
139 *         and false otherwise.
140 */
141RTEMS_INLINE_ROUTINE bool _CORE_spinlock_Is_busy(
142  CORE_spinlock_Control  *the_spinlock
143)
144{
145  return (the_spinlock->users != 0);
146}
147
148/** @} */
149
150#ifdef __cplusplus
151}
152#endif
153
154#endif
155/* end of include file */
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