blob: a4aadb7410b8b4cb5d3f74d1a4b66945a7d9e5b8 (
plain) (
blame)
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
|
/*
* Mutex Handler
*
* DESCRIPTION:
*
* This package is the implementation of the Mutex Handler.
* This handler provides synchronization and mutual exclusion capabilities.
*
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include <rtems/system.h>
#include <rtems/score/isr.h>
#include <rtems/score/coremutex.h>
#include <rtems/score/states.h>
#include <rtems/score/thread.h>
#include <rtems/score/threadq.h>
/*PAGE
*
* _CORE_mutex_Seize (interrupt blocking support)
*
* This routine blocks the caller thread after an attempt attempts to obtain
* the specified mutex has failed.
*
* Input parameters:
* the_mutex - pointer to mutex control block
* timeout - number of ticks to wait (0 means forever)
*/
void _CORE_mutex_Seize_interrupt_blocking(
CORE_mutex_Control *the_mutex,
Watchdog_Interval timeout
)
{
Thread_Control *executing;
executing = _Thread_Executing;
switch ( the_mutex->Attributes.discipline ) {
case CORE_MUTEX_DISCIPLINES_FIFO:
case CORE_MUTEX_DISCIPLINES_PRIORITY:
case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
break;
case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
if ( the_mutex->holder->current_priority > executing->current_priority ) {
_Thread_Change_priority(
the_mutex->holder,
executing->current_priority,
FALSE
);
}
break;
}
the_mutex->blocked_count++;
_Thread_queue_Enqueue( &the_mutex->Wait_queue, timeout );
if ( _Thread_Executing->Wait.return_code == CORE_MUTEX_STATUS_SUCCESSFUL ) {
switch ( the_mutex->Attributes.discipline ) {
case CORE_MUTEX_DISCIPLINES_FIFO:
case CORE_MUTEX_DISCIPLINES_PRIORITY:
case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
break;
case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
if ( the_mutex->Attributes.priority_ceiling <
executing->current_priority ) {
_Thread_Change_priority(
executing,
the_mutex->Attributes.priority_ceiling,
FALSE
);
};
break;
}
}
_Thread_Enable_dispatch();
}
#if !defined(USE_INLINES)
int _CORE_mutex_Seize_interrupt_trylock(
CORE_mutex_Control *the_mutex,
ISR_Level *level_p
)
{
Thread_Control *executing;
ISR_Level level = *level_p;
/* disabled when you get here */
executing = _Thread_Executing;
executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL;
if ( !_CORE_mutex_Is_locked( the_mutex ) ) {
the_mutex->lock = CORE_MUTEX_LOCKED;
the_mutex->holder = executing;
the_mutex->holder_id = executing->Object.id;
the_mutex->nest_count = 1;
executing->resource_count++;
if ( the_mutex->Attributes.discipline !=
CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING ) {
_ISR_Enable( level );
return 0;
}
/* else must be CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING */
{
Priority_Control ceiling;
Priority_Control current;
ceiling = the_mutex->Attributes.priority_ceiling;
current = executing->current_priority;
if ( current == ceiling ) {
_ISR_Enable( level );
return 0;
}
if ( current > ceiling ) {
_Thread_Disable_dispatch();
_ISR_Enable( level );
_Thread_Change_priority(
the_mutex->holder,
the_mutex->Attributes.priority_ceiling,
FALSE
);
_Thread_Enable_dispatch();
return 0;
}
/* if ( current < ceiling ) */ {
executing->Wait.return_code = CORE_MUTEX_STATUS_CEILING_VIOLATED;
the_mutex->nest_count = 0; /* undo locking above */
executing->resource_count--; /* undo locking above */
_ISR_Enable( level );
return 0;
}
}
return 0;
}
return 1;
}
#endif
|
