OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [exec/] [score/] [src/] [coremutexseize.c] - Blame information for rev 279

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 30 unneback 
/*
2 
 *  Mutex Handler
3 
 *
4 
 *  DESCRIPTION:
5 
 *
6 
 *  This package is the implementation of the Mutex Handler.
7 
 *  This handler provides synchronization and mutual exclusion capabilities.
8 
 *
9 
 *  COPYRIGHT (c) 1989-1999.
10 
 *  On-Line Applications Research Corporation (OAR).
11 
 *
12 
 *  The license and distribution terms for this file may be
13 
 *  found in the file LICENSE in this distribution or at
14 
 *  http://www.OARcorp.com/rtems/license.html.
15 
 *
16 
 *  $Id: coremutexseize.c,v 1.2 2001-09-27 11:59:34 chris Exp $
17 
 */
18 
 
19 
#include <rtems/system.h>
20 
#include <rtems/score/isr.h>
21 
#include <rtems/score/coremutex.h>
22 
#include <rtems/score/states.h>
23 
#include <rtems/score/thread.h>
24 
#include <rtems/score/threadq.h>
25 
 
26 
/*PAGE
27 
 *
28 
 *  _CORE_mutex_Seize
29 
 *
30 
 *  This routine attempts to allocate a mutex to the calling thread.
31 
 *
32 
 *  Input parameters:
33 
 *    the_mutex - pointer to mutex control block
34 
 *    id        - id of object to wait on
35 
 *    wait      - TRUE if wait is allowed, FALSE otherwise
36 
 *    timeout   - number of ticks to wait (0 means forever)
37 
 *
38 
 *  Output parameters:  NONE
39 
 *
40 
 *  INTERRUPT LATENCY:
41 
 *    available
42 
 *    wait
43 
 */
44 
 
45 
void _CORE_mutex_Seize(
46 
  CORE_mutex_Control  *the_mutex,
47 
  Objects_Id           id,
48 
  boolean              wait,
49 
  Watchdog_Interval    timeout
50 
)
51 
{
52 
  Thread_Control *executing;
53 
  ISR_Level       level;
54 
 
55 
  executing = _Thread_Executing;
56 
  switch ( the_mutex->Attributes.discipline ) {
57 
    case CORE_MUTEX_DISCIPLINES_FIFO:
58 
    case CORE_MUTEX_DISCIPLINES_PRIORITY:
59 
    case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
60 
      break;
61 
    case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
62 
      if ( executing->current_priority <
63 
                              the_mutex->Attributes.priority_ceiling) {
64 
        executing->Wait.return_code = CORE_MUTEX_STATUS_CEILING_VIOLATED;
65 
        return;
66 
      }
67 
  }
68 
  executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL;
69 
  _ISR_Disable( level );
70 
  if ( ! _CORE_mutex_Is_locked( the_mutex ) ) {
71 
    the_mutex->lock       = CORE_MUTEX_LOCKED;
72 
    the_mutex->holder     = executing;
73 
    the_mutex->holder_id  = executing->Object.id;
74 
    the_mutex->nest_count = 1;
75 
    executing->resource_count++;
76 
    _ISR_Enable( level );
77 
    switch ( the_mutex->Attributes.discipline ) {
78 
      case CORE_MUTEX_DISCIPLINES_FIFO:
79 
      case CORE_MUTEX_DISCIPLINES_PRIORITY:
80 
      case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
81 
        /* already the highest priority */
82 
        break;
83 
      case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
84 
      if ( the_mutex->Attributes.priority_ceiling <
85 
                                           executing->current_priority ) {
86 
        _Thread_Change_priority(
87 
          the_mutex->holder,
88 
          the_mutex->Attributes.priority_ceiling,
89 
          FALSE
90 
        );
91 
      }
92 
    }
93 
    executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL;
94 
    return;
95 
  }
96 
 
97 
  if ( _Thread_Is_executing( the_mutex->holder ) ) {
98 
    switch ( the_mutex->Attributes.lock_nesting_behavior ) {
99 
      case CORE_MUTEX_NESTING_ACQUIRES:
100 
        the_mutex->nest_count++;
101 
        _ISR_Enable( level );
102 
        return;
103 
      case CORE_MUTEX_NESTING_IS_ERROR:
104 
        executing->Wait.return_code = CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED;
105 
        _ISR_Enable( level );
106 
        return;
107 
      case CORE_MUTEX_NESTING_BLOCKS:
108 
        break;
109 
    }
110 
  }
111 
 
112 
  if ( !wait ) {
113 
    _ISR_Enable( level );
114 
    executing->Wait.return_code = CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT;
115 
    return;
116 
  }
117 
 
118 
  _Thread_queue_Enter_critical_section( &the_mutex->Wait_queue );
119 
  executing->Wait.queue = &the_mutex->Wait_queue;
120 
  executing->Wait.id    = id;
121 
  _ISR_Enable( level );
122 
 
123 
  switch ( the_mutex->Attributes.discipline ) {
124 
    case CORE_MUTEX_DISCIPLINES_FIFO:
125 
    case CORE_MUTEX_DISCIPLINES_PRIORITY:
126 
    case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
127 
      break;
128 
    case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
129 
      if ( the_mutex->holder->current_priority > executing->current_priority ) {
130 
        _Thread_Change_priority(
131 
          the_mutex->holder,
132 
          executing->current_priority,
133 
          FALSE
134 
        );
135 
      }
136 
      break;
137 
  }
138 
 
139 
  _Thread_queue_Enqueue( &the_mutex->Wait_queue, timeout );
140 
 
141 
  if ( _Thread_Executing->Wait.return_code == CORE_MUTEX_STATUS_SUCCESSFUL ) {
142 
    switch ( the_mutex->Attributes.discipline ) {
143 
      case CORE_MUTEX_DISCIPLINES_FIFO:
144 
      case CORE_MUTEX_DISCIPLINES_PRIORITY:
145 
      case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
146 
        break;
147 
      case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
148 
        if ( the_mutex->Attributes.priority_ceiling <
149 
                                           executing->current_priority ) {
150 
          _Thread_Change_priority(
151 
            executing,
152 
            the_mutex->Attributes.priority_ceiling,
153 
            FALSE
154 
          );
155 
        };
156 
        break;
157 
    }
158 
  }
159 
}
160 
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.