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
|
/**
* @file
*
* @ingroup RTEMSScoreBarrier
*
* @brief This source file contains the implementation of
* _CORE_barrier_Seize().
*/
/*
* COPYRIGHT (c) 1989-2006.
* 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.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/corebarrierimpl.h>
#include <rtems/score/statesimpl.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/threadqops.h>
static void _CORE_barrier_Thread_queue_extract(
Thread_queue_Queue *queue,
Thread_Control *the_thread,
Thread_queue_Context *queue_context
)
{
CORE_barrier_Control *the_barrier;
the_barrier = RTEMS_CONTAINER_OF(
queue,
CORE_barrier_Control,
Wait_queue.Queue
);
--the_barrier->number_of_waiting_threads;
_Thread_queue_FIFO_extract(
&the_barrier->Wait_queue.Queue,
the_thread,
queue_context
);
}
const Thread_queue_Operations _CORE_barrier_Thread_queue_operations = {
.priority_actions = _Thread_queue_Do_nothing_priority_actions,
.enqueue = _Thread_queue_FIFO_enqueue,
.extract = _CORE_barrier_Thread_queue_extract,
.surrender = _Thread_queue_FIFO_surrender,
.first = _Thread_queue_FIFO_first
};
Status_Control _CORE_barrier_Seize(
CORE_barrier_Control *the_barrier,
Thread_Control *executing,
bool wait,
Thread_queue_Context *queue_context
)
{
uint32_t new_number_of_waiting_threads;
_CORE_barrier_Acquire_critical( the_barrier, queue_context );
/*
* In theory, this calculation can overflow. If this happens, then about 4
* billion threads are accidentally released. Currently, the system limit
* for threads is a bit lower with three times OBJECTS_INDEX_MASK - 1.
*/
new_number_of_waiting_threads = the_barrier->number_of_waiting_threads + 1;
if ( new_number_of_waiting_threads == the_barrier->maximum_count ) {
_CORE_barrier_Surrender( the_barrier, queue_context );
return STATUS_BARRIER_AUTOMATICALLY_RELEASED;
} else {
the_barrier->number_of_waiting_threads = new_number_of_waiting_threads;
_Thread_queue_Context_set_thread_state(
queue_context,
STATES_WAITING_FOR_BARRIER
);
_Thread_queue_Enqueue(
&the_barrier->Wait_queue.Queue,
&_CORE_barrier_Thread_queue_operations,
executing,
queue_context
);
return _Thread_Wait_get_status( executing );
}
}
|
