source: rtems/cpukit/score/src/threadmp.c @ ac7d5ef0

4.104.114.84.95
Last change on this file since ac7d5ef0 was ac7d5ef0, checked in by Joel Sherrill <joel.sherrill@…>, on May 11, 1995 at 5:39:37 PM

Initial revision

  • Property mode set to 100644
File size: 4.7 KB
Line 
1/*
2 *  Multiprocessing Support for the Thread Handler
3 *
4 *
5 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
6 *  On-Line Applications Research Corporation (OAR).
7 *  All rights assigned to U.S. Government, 1994.
8 *
9 *  This material may be reproduced by or for the U.S. Government pursuant
10 *  to the copyright license under the clause at DFARS 252.227-7013.  This
11 *  notice must appear in all copies of this file and its derivatives.
12 *
13 *  $Id$
14 */
15
16#include <rtems/system.h>
17#include <rtems/priority.h>
18#include <rtems/thread.h>
19#include <rtems/wkspace.h>
20
21/*PAGE
22 *
23 *  _Thread_MP_Handler_initialization
24 *
25 */
26
27void _Thread_MP_Handler_initialization (
28  unsigned32  maximum_proxies
29)
30{
31
32  _Chain_Initialize_empty( &_Thread_MP_Active_proxies );
33
34  if ( maximum_proxies == 0 ) {
35    _Chain_Initialize_empty( &_Thread_MP_Inactive_proxies );
36    return;
37  }
38
39
40  _Chain_Initialize(
41    &_Thread_MP_Inactive_proxies,
42    _Workspace_Allocate_or_fatal_error(
43      maximum_proxies * sizeof( Thread_Proxy_control )
44    ),
45    maximum_proxies,
46    sizeof( Thread_Proxy_control )
47  );
48
49}
50
51/*PAGE
52 *
53 *  _Thread_MP_Allocate_proxy
54 *
55 */
56
57Thread_Control *_Thread_MP_Allocate_proxy (
58  States_Control  the_state
59)
60{
61  Thread_Control       *the_thread;
62  Thread_Proxy_control *the_proxy;
63
64  the_thread = (Thread_Control *)_Chain_Get( &_Thread_MP_Inactive_proxies );
65
66  if ( !_Thread_Is_null( the_thread ) ) {
67
68    the_proxy = (Thread_Proxy_control *) the_thread;
69
70    _Thread_Executing->Wait.return_code = RTEMS_PROXY_BLOCKING;
71
72    the_proxy->receive_packet = _Thread_MP_Receive->receive_packet;
73
74    the_proxy->Object.id = _Thread_MP_Receive->receive_packet->source_tid;
75
76    the_proxy->current_priority =
77      _Thread_MP_Receive->receive_packet->source_priority;
78
79    the_proxy->current_state = _States_Set( STATES_DORMANT, the_state );
80
81    the_proxy->Wait = _Thread_Executing->Wait;
82
83    _Chain_Append( &_Thread_MP_Active_proxies, &the_proxy->Active );
84
85    return the_thread;
86  }
87
88  rtems_fatal_error_occurred( RTEMS_TOO_MANY );
89
90  /*
91   *  NOTE: The following return insures that the compiler will
92   *        think that all paths return a value.
93   */
94
95  return NULL;
96}
97
98/*PAGE
99 *
100 *  _Thread_MP_Find_proxy
101 *
102 */
103
104/*
105 *  The following macro provides the offset of the Active element
106 *  in the Thread_Proxy_control structure.  This is the logical
107 *  equivalent of the POSITION attribute in Ada.
108 */
109
110#define _Thread_MP_Proxy_Active_offset \
111     ((unsigned32)&(((Thread_Proxy_control *)0))->Active)
112
113Thread_Control *_Thread_MP_Find_proxy (
114  Objects_Id  the_id
115)
116{
117
118  Chain_Node           *proxy_node;
119  Thread_Control       *the_thread;
120  ISR_Level             level;
121
122restart:
123
124  _ISR_Disable( level );
125
126    for (  proxy_node = _Thread_MP_Active_proxies.first;
127           !_Chain_Is_tail( &_Thread_MP_Active_proxies, proxy_node ) ;
128        ) {
129
130      the_thread = _Addresses_Subtract_offset(
131                     proxy_node,
132                     _Thread_MP_Proxy_Active_offset
133                   );
134
135      if ( _Objects_Are_ids_equal( the_thread->Object.id, the_id ) ) {
136        _ISR_Enable( level );
137        return the_thread;
138      }
139
140      _ISR_Flash( level );
141
142      proxy_node = proxy_node->next;
143
144      /*
145       *  A proxy which is only dormant is not in a blocking state.
146       *  Therefore, we are looking at proxy which has been moved from
147       *  active to inactive chain (by an ISR) and need to restart
148       *  the search.
149       */
150
151      if ( _States_Is_only_dormant( the_thread->current_state ) ) {
152        _ISR_Enable( level );
153        goto restart;
154      }
155    }
156
157  _ISR_Enable( level );
158  return NULL;
159}
160
161/*PAGE
162 *
163 *  _Thread_MP_Block
164 *
165 */
166
167void _Thread_MP_Block( void )
168{
169  ISR_Level   level;
170
171  _ISR_Disable( level );
172
173    if ( _Thread_MP_Receive->Notepads[ 0 ] != 0 ) {
174      _Priority_Remove_from_bit_map( &_Thread_MP_Receive->Priority_map );
175
176      _Thread_MP_Receive->current_state = STATES_SUSPENDED;
177
178      _ISR_Flash( level );
179
180      _Thread_Calculate_heir();
181
182      _Context_Switch_necessary = TRUE;
183
184      _ISR_Enable( level );
185
186      _Thread_Dispatch_disable_level = 0;
187
188      _Thread_Dispatch();
189
190      return;
191
192    }
193  _ISR_Enable( level );
194
195}
196
197/*PAGE
198 *
199 *  _Thread_MP_Ready
200 *
201 */
202
203void _Thread_MP_Ready( void )
204{
205  ISR_Level   level;
206
207  _ISR_Disable( level );
208
209    if ( _States_Is_suspended( _Thread_MP_Receive->current_state ) ) {
210      _Priority_Add_to_bit_map( &_Thread_MP_Receive->Priority_map );
211
212      _Thread_MP_Receive->current_state = STATES_READY;
213
214      _Thread_Heir = _Thread_MP_Receive;
215
216      _Context_Switch_necessary = TRUE;
217
218      _ISR_Enable( level );
219
220      if ( _Thread_Is_dispatching_enabled() )
221        _Thread_Dispatch();
222
223    } else {
224
225      _Thread_MP_Receive->Notepads[ 0 ] = 0;
226      _ISR_Enable( level );
227
228    }
229}
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