source: rtems/cpukit/rtems/src/regiongetsegment.c @ 626ace4

4.104.114.84.95
Last change on this file since 626ace4 was 626ace4, checked in by Joel Sherrill <joel.sherrill@…>, on Oct 15, 2004 at 9:05:07 PM

2004-10-15 Joel Sherrill <joel@…>

PR 692/rtems

  • rtems/src/regiongetsegment.c, rtems/src/regionreturnsegment.c: The Region Manager did not follow the proper protocol when blocking and unblocking tasks waiting on buffers. This was a bug introduced with the transition to an Allocation Mutex.
  • Property mode set to 100644
File size: 3.2 KB
Line 
1/*
2 *  Region Manager
3 *
4 *
5 *  COPYRIGHT (c) 1989-1999.
6 *  On-Line Applications Research Corporation (OAR).
7 *
8 *  The license and distribution terms for this file may be
9 *  found in the file LICENSE in this distribution or at
10 *  http://www.rtems.com/license/LICENSE.
11 *
12 *  $Id$
13 */
14
15#include <rtems/system.h>
16#include <rtems/rtems/status.h>
17#include <rtems/rtems/support.h>
18#include <rtems/score/object.h>
19#include <rtems/rtems/options.h>
20#include <rtems/rtems/region.h>
21#include <rtems/score/states.h>
22#include <rtems/score/thread.h>
23#include <rtems/score/apimutex.h>
24
25/*PAGE
26 *
27 *  rtems_region_get_segment
28 *
29 *  This directive will obtain a segment from the given region.
30 *
31 *  Input parameters:
32 *    id         - region id
33 *    size       - segment size in bytes
34 *    option_set - wait option
35 *    timeout    - number of ticks to wait (0 means wait forever)
36 *    segment    - pointer to segment address
37 *
38 *  Output parameters:
39 *    segment    - pointer to segment address filled in
40 *    RTEMS_SUCCESSFUL - if successful
41 *    error code - if unsuccessful
42 */
43
44rtems_status_code rtems_region_get_segment(
45  Objects_Id         id,
46  uint32_t           size,
47  rtems_option       option_set,
48  rtems_interval     timeout,
49  void              **segment
50)
51{
52  register Region_Control *the_region;
53  Objects_Locations        location;
54  Thread_Control          *executing;
55  void                    *the_segment;
56
57  if ( !segment )
58    return RTEMS_INVALID_ADDRESS;
59
60  *segment = NULL;
61
62  if ( size == 0 )
63    return RTEMS_INVALID_SIZE;
64
65  _RTEMS_Lock_allocator();
66  executing  = _Thread_Executing;
67  the_region = _Region_Get( id, &location );
68  switch ( location ) {
69    case OBJECTS_REMOTE:        /* this error cannot be returned */
70      _RTEMS_Unlock_allocator();
71      return RTEMS_INTERNAL_ERROR;
72
73    case OBJECTS_ERROR:
74      _RTEMS_Unlock_allocator();
75      return RTEMS_INVALID_ID;
76
77    case OBJECTS_LOCAL:
78      if ( size > the_region->maximum_segment_size ) {
79        _RTEMS_Unlock_allocator();
80        return RTEMS_INVALID_SIZE;
81      }
82
83      _Region_Debug_Walk( the_region, 1 );
84
85      the_segment = _Region_Allocate_segment( the_region, size );
86
87      _Region_Debug_Walk( the_region, 2 );
88
89      if ( the_segment ) {
90        the_region->number_of_used_blocks += 1;
91        _RTEMS_Unlock_allocator();
92        *segment = the_segment;
93        return RTEMS_SUCCESSFUL;
94      }
95
96      if ( _Options_Is_no_wait( option_set ) ) {
97        _RTEMS_Unlock_allocator();
98        return RTEMS_UNSATISFIED;
99      }
100
101      /*
102       *  Switch from using the memory allocation mutex to using a
103       *  dispatching disabled critical section.  We have to do this
104       *  because this thread is going to block.
105       */
106      _Thread_Disable_dispatch();
107      _RTEMS_Unlock_allocator();
108
109      executing->Wait.queue           = &the_region->Wait_queue;
110      executing->Wait.id              = id;
111      executing->Wait.count           = size;
112      executing->Wait.return_argument = segment;
113
114      _Thread_queue_Enter_critical_section( &the_region->Wait_queue );
115
116      _Thread_queue_Enqueue( &the_region->Wait_queue, timeout );
117
118      _Thread_Enable_dispatch();
119
120      return (rtems_status_code) executing->Wait.return_code;
121  }
122
123  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */
124}
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