source: rtems/cpukit/score/src/threadmp.c @ 5e9b32b

4.104.114.84.95
Last change on this file since 5e9b32b was 5e9b32b, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 26, 1995 at 7:27:15 PM

posix support initially added

  • Property mode set to 100644
File size: 3.7 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/score/priority.h>
18#include <rtems/score/thread.h>
19#include <rtems/score/wkspace.h>
20#include <rtems/score/isr.h>
21
22/*PAGE
23 *
24 *  _Thread_MP_Handler_initialization
25 *
26 */
27
28void _Thread_MP_Handler_initialization (
29  unsigned32  maximum_proxies
30)
31{
32
33  _Chain_Initialize_empty( &_Thread_MP_Active_proxies );
34
35  if ( maximum_proxies == 0 ) {
36    _Chain_Initialize_empty( &_Thread_MP_Inactive_proxies );
37    return;
38  }
39
40
41  _Chain_Initialize(
42    &_Thread_MP_Inactive_proxies,
43    _Workspace_Allocate_or_fatal_error(
44      maximum_proxies * sizeof( Thread_Proxy_control )
45    ),
46    maximum_proxies,
47    sizeof( Thread_Proxy_control )
48  );
49
50}
51
52/*PAGE
53 *
54 *  _Thread_MP_Allocate_proxy
55 *
56 */
57
58Thread_Control *_Thread_MP_Allocate_proxy (
59  States_Control  the_state
60)
61{
62  Thread_Control       *the_thread;
63  Thread_Proxy_control *the_proxy;
64
65  the_thread = (Thread_Control *)_Chain_Get( &_Thread_MP_Inactive_proxies );
66
67  if ( !_Thread_Is_null( the_thread ) ) {
68
69    the_proxy = (Thread_Proxy_control *) the_thread;
70
71    _Thread_Executing->Wait.return_code = THREAD_STATUS_PROXY_BLOCKING;
72
73    the_proxy->receive_packet = _Thread_MP_Receive->receive_packet;
74
75    the_proxy->Object.id = _Thread_MP_Receive->receive_packet->source_tid;
76
77    the_proxy->current_priority =
78      _Thread_MP_Receive->receive_packet->source_priority;
79
80    the_proxy->current_state = _States_Set( STATES_DORMANT, the_state );
81
82    the_proxy->Wait = _Thread_Executing->Wait;
83
84    _Chain_Append( &_Thread_MP_Active_proxies, &the_proxy->Active );
85
86    return the_thread;
87  }
88
89  _Internal_error_Occurred(
90    INTERNAL_ERROR_CORE,
91    TRUE,
92    INTERNAL_ERROR_OUT_OF_PROXIES
93  );
94
95  /*
96   *  NOTE: The following return insures that the compiler will
97   *        think that all paths return a value.
98   */
99
100  return NULL;
101}
102
103/*PAGE
104 *
105 *  _Thread_MP_Find_proxy
106 *
107 */
108
109/*
110 *  The following macro provides the offset of the Active element
111 *  in the Thread_Proxy_control structure.  This is the logical
112 *  equivalent of the POSITION attribute in Ada.
113 */
114
115#define _Thread_MP_Proxy_Active_offset \
116     ((unsigned32)&(((Thread_Proxy_control *)0))->Active)
117
118Thread_Control *_Thread_MP_Find_proxy (
119  Objects_Id  the_id
120)
121{
122
123  Chain_Node           *proxy_node;
124  Thread_Control       *the_thread;
125  ISR_Level             level;
126
127restart:
128
129  _ISR_Disable( level );
130
131    for (  proxy_node = _Thread_MP_Active_proxies.first;
132           !_Chain_Is_tail( &_Thread_MP_Active_proxies, proxy_node ) ;
133        ) {
134
135      the_thread = _Addresses_Subtract_offset(
136                     proxy_node,
137                     _Thread_MP_Proxy_Active_offset
138                   );
139
140      if ( _Objects_Are_ids_equal( the_thread->Object.id, the_id ) ) {
141        _ISR_Enable( level );
142        return the_thread;
143      }
144
145      _ISR_Flash( level );
146
147      proxy_node = proxy_node->next;
148
149      /*
150       *  A proxy which is only dormant is not in a blocking state.
151       *  Therefore, we are looking at proxy which has been moved from
152       *  active to inactive chain (by an ISR) and need to restart
153       *  the search.
154       */
155
156      if ( _States_Is_only_dormant( the_thread->current_state ) ) {
157        _ISR_Enable( level );
158        goto restart;
159      }
160    }
161
162  _ISR_Enable( level );
163  return NULL;
164}
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