source: rtems/cpukit/score/src/threadqdequeuepriority.c @ 4e97166

4.104.114.84.95
Last change on this file since 4e97166 was a8eed23, checked in by Ralf Corsepius <ralf.corsepius@…>, on 01/27/05 at 05:57:05

Include config.h.

  • Property mode set to 100644
File size: 3.5 KB
Line 
1/*
2 *  Thread Queue Handler
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#if HAVE_CONFIG_H
16#include "config.h"
17#endif
18
19#include <rtems/system.h>
20#include <rtems/score/chain.h>
21#include <rtems/score/isr.h>
22#include <rtems/score/object.h>
23#include <rtems/score/states.h>
24#include <rtems/score/thread.h>
25#include <rtems/score/threadq.h>
26#include <rtems/score/tqdata.h>
27
28/*PAGE
29 *
30 *  _Thread_queue_Dequeue_priority
31 *
32 *  This routine removes a thread from the specified PRIORITY based
33 *  threadq, unblocks it, and cancels its timeout timer.
34 *
35 *  Input parameters:
36 *    the_thread_queue - pointer to thread queue
37 *
38 *  Output parameters:
39 *    returns - thread dequeued or NULL
40 *
41 *  INTERRUPT LATENCY:
42 *    only case
43 */
44
45Thread_Control *_Thread_queue_Dequeue_priority(
46  Thread_queue_Control *the_thread_queue
47)
48{
49  uint32_t        index;
50  ISR_Level       level;
51  Thread_Control *the_thread = NULL;  /* just to remove warnings */
52  Thread_Control *new_first_thread;
53  Chain_Node     *new_first_node;
54  Chain_Node     *new_second_node;
55  Chain_Node     *last_node;
56  Chain_Node     *next_node;
57  Chain_Node     *previous_node;
58
59  _ISR_Disable( level );
60  for( index=0 ;
61       index < TASK_QUEUE_DATA_NUMBER_OF_PRIORITY_HEADERS ;
62       index++ ) {
63    if ( !_Chain_Is_empty( &the_thread_queue->Queues.Priority[ index ] ) ) {
64      the_thread = (Thread_Control *)
65                    the_thread_queue->Queues.Priority[ index ].first;
66      goto dequeue;
67    }
68  }
69
70  switch ( the_thread_queue->sync_state ) {
71    case THREAD_QUEUE_SYNCHRONIZED:
72    case THREAD_QUEUE_SATISFIED:
73      _ISR_Enable( level );
74      return NULL;
75
76    case THREAD_QUEUE_NOTHING_HAPPENED:
77    case THREAD_QUEUE_TIMEOUT:
78      the_thread_queue->sync_state = THREAD_QUEUE_SATISFIED;
79      _ISR_Enable( level );
80      return _Thread_Executing;
81  }
82
83dequeue:
84  new_first_node   = the_thread->Wait.Block2n.first;
85  new_first_thread = (Thread_Control *) new_first_node;
86  next_node        = the_thread->Object.Node.next;
87  previous_node    = the_thread->Object.Node.previous;
88
89  if ( !_Chain_Is_empty( &the_thread->Wait.Block2n ) ) {
90    last_node       = the_thread->Wait.Block2n.last;
91    new_second_node = new_first_node->next;
92
93    previous_node->next      = new_first_node;
94    next_node->previous      = new_first_node;
95    new_first_node->next     = next_node;
96    new_first_node->previous = previous_node;
97
98    if ( !_Chain_Has_only_one_node( &the_thread->Wait.Block2n ) ) {
99                                                /* > two threads on 2-n */
100      new_second_node->previous =
101                _Chain_Head( &new_first_thread->Wait.Block2n );
102
103      new_first_thread->Wait.Block2n.first = new_second_node;
104      new_first_thread->Wait.Block2n.last  = last_node;
105
106      last_node->next = _Chain_Tail( &new_first_thread->Wait.Block2n );
107    }
108  } else {
109    previous_node->next = next_node;
110    next_node->previous = previous_node;
111  }
112
113  if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
114    _ISR_Enable( level );
115    _Thread_Unblock( the_thread );
116  } else {
117    _Watchdog_Deactivate( &the_thread->Timer );
118    _ISR_Enable( level );
119    (void) _Watchdog_Remove( &the_thread->Timer );
120    _Thread_Unblock( the_thread );
121  }
122
123#if defined(RTEMS_MULTIPROCESSING)
124  if ( !_Objects_Is_local_id( the_thread->Object.id ) )
125    _Thread_MP_Free_proxy( the_thread );
126#endif
127  return( the_thread );
128}
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