chschd.h
8.55 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
---
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes ChibiOS/RT, without being obliged to provide
the source code for any proprietary components. See the file exception.txt
for full details of how and when the exception can be applied.
*/
/**
* @file chschd.h
* @brief Scheduler macros and structures.
*
* @addtogroup scheduler
* @{
*/
#ifndef _CHSCHD_H_
#define _CHSCHD_H_
/**
* @name Wakeup status codes
* @{
*/
#define RDY_OK 0 /**< @brief Normal wakeup message. */
#define RDY_TIMEOUT -1 /**< @brief Wakeup caused by a timeout
condition. */
#define RDY_RESET -2 /**< @brief Wakeup caused by a reset
condition. */
/** @} */
/**
* @name Priority constants
* @{
*/
#define NOPRIO 0 /**< @brief Ready list header priority. */
#define IDLEPRIO 1 /**< @brief Idle thread priority. */
#define LOWPRIO 2 /**< @brief Lowest user priority. */
#define NORMALPRIO 64 /**< @brief Normal user priority. */
#define HIGHPRIO 127 /**< @brief Highest user priority. */
#define ABSPRIO 255 /**< @brief Greatest possible priority. */
/** @} */
/**
* @name Special time constants
* @{
*/
/**
* @brief Zero time specification for some functions with a timeout
* specification.
* @note Not all functions accept @p TIME_IMMEDIATE as timeout parameter,
* see the specific function documentation.
*/
#define TIME_IMMEDIATE ((systime_t)0)
/**
* @brief Infinite time specification for all functions with a timeout
* specification.
*/
#define TIME_INFINITE ((systime_t)-1)
/** @} */
/**
* @brief Returns the priority of the first thread on the given ready list.
*
* @notapi
*/
#define firstprio(rlp) ((rlp)->p_next->p_prio)
/**
* @extends ThreadsQueue
*
* @brief Ready list header.
*/
#if !defined(PORT_OPTIMIZED_READYLIST_STRUCT) || defined(__DOXYGEN__)
typedef struct {
ThreadsQueue r_queue; /**< @brief Threads queue. */
tprio_t r_prio; /**< @brief This field must be
initialized to zero. */
struct context r_ctx; /**< @brief Not used, present because
offsets. */
#if CH_USE_REGISTRY || defined(__DOXYGEN__)
Thread *r_newer; /**< @brief Newer registry element. */
Thread *r_older; /**< @brief Older registry element. */
#endif
/* End of the fields shared with the Thread structure.*/
#if (CH_TIME_QUANTUM > 0) || defined(__DOXYGEN__)
cnt_t r_preempt; /**< @brief Round robin counter. */
#endif
Thread *r_current; /**< @brief The currently running
thread. */
} ReadyList;
#endif /* !defined(PORT_OPTIMIZED_READYLIST_STRUCT) */
#if !defined(PORT_OPTIMIZED_RLIST_EXT) && !defined(__DOXYGEN__)
extern ReadyList rlist;
#endif /* !defined(PORT_OPTIMIZED_RLIST_EXT) */
/**
* @brief Current thread pointer access macro.
* @note This macro is not meant to be used in the application code but
* only from within the kernel, use the @p chThdSelf() API instead.
* @note It is forbidden to use this macro in order to change the pointer
* (currp = something), use @p setcurrp() instead.
*/
#if !defined(PORT_OPTIMIZED_CURRP) || defined(__DOXYGEN__)
#define currp rlist.r_current
#endif /* !defined(PORT_OPTIMIZED_CURRP) */
/**
* @brief Current thread pointer change macro.
* @note This macro is not meant to be used in the application code but
* only from within the kernel.
*
* @notapi
*/
#if !defined(PORT_OPTIMIZED_SETCURRP) || defined(__DOXYGEN__)
#define setcurrp(tp) (currp = (tp))
#endif /* !defined(PORT_OPTIMIZED_SETCURRP) */
/*
* Scheduler APIs.
*/
#ifdef __cplusplus
extern "C" {
#endif
void _scheduler_init(void);
#if !defined(PORT_OPTIMIZED_READYI)
Thread *chSchReadyI(Thread *tp);
#endif
#if !defined(PORT_OPTIMIZED_GOSLEEPS)
void chSchGoSleepS(tstate_t newstate);
#endif
#if !defined(PORT_OPTIMIZED_GOSLEEPTIMEOUTS)
msg_t chSchGoSleepTimeoutS(tstate_t newstate, systime_t time);
#endif
#if !defined(PORT_OPTIMIZED_WAKEUPS)
void chSchWakeupS(Thread *tp, msg_t msg);
#endif
#if !defined(PORT_OPTIMIZED_RESCHEDULES)
void chSchRescheduleS(void);
#endif
#if !defined(PORT_OPTIMIZED_ISPREEMPTIONREQUIRED)
bool_t chSchIsPreemptionRequired(void);
#endif
#if !defined(PORT_OPTIMIZED_DORESCHEDULE)
void chSchDoReschedule(void);
#endif
#ifdef __cplusplus
}
#endif
/**
* @name Macro Functions
* @{
*/
/**
* @brief Determines if the current thread must reschedule.
* @details This function returns @p TRUE if there is a ready thread with
* higher priority.
*
* @iclass
*/
#if !defined(PORT_OPTIMIZED_ISRESCHREQUIREDI) || defined(__DOXYGEN__)
#define chSchIsRescRequiredI() (firstprio(&rlist.r_queue) > currp->p_prio)
#endif /* !defined(PORT_OPTIMIZED_ISRESCHREQUIREDI) */
/**
* @brief Determines if yielding is possible.
* @details This function returns @p TRUE if there is a ready thread with
* equal or higher priority.
*
* @sclass
*/
#if !defined(PORT_OPTIMIZED_CANYIELDS) || defined(__DOXYGEN__)
#define chSchCanYieldS() (firstprio(&rlist.r_queue) >= currp->p_prio)
#endif /* !defined(PORT_OPTIMIZED_CANYIELDS) */
/**
* @brief Yields the time slot.
* @details Yields the CPU control to the next thread in the ready list with
* equal or higher priority, if any.
*
* @sclass
*/
#if !defined(PORT_OPTIMIZED_DOYIELDS) || defined(__DOXYGEN__)
#define chSchDoYieldS() { \
if (chSchCanYieldS()) \
chSchDoReschedule(); \
}
#endif /* !defined(PORT_OPTIMIZED_DOYIELDS) */
/**
* @brief Inline-able preemption code.
* @details This is the common preemption code, this function must be invoked
* exclusively from the port layer.
*
* @special
*/
#if (CH_TIME_QUANTUM > 0) || defined(__DOXYGEN__)
#define chSchPreemption() { \
tprio_t p1 = firstprio(&rlist.r_queue); \
tprio_t p2 = currp->p_prio; \
if (rlist.r_preempt) { \
if (p1 > p2) \
chSchDoReschedule(); \
} \
else { \
if (p1 >= p2) \
chSchDoReschedule(); \
} \
}
#else /* CH_TIME_QUANTUM == 0 */
#define chSchPreemption() { \
if (p1 >= p2) \
chSchDoReschedule(); \
}
#endif /* CH_TIME_QUANTUM == 0 */
/** @} */
#endif /* _CHSCHD_H_ */
/** @} */