source: rtems/cpukit/score/src/schedulercbsnodeinit.c @ dafa5d88

5
Last change on this file since dafa5d88 was 5c3d250, checked in by Sebastian Huber <sebastian.huber@…>, on 07/04/14 at 12:34:23

score: Implement scheduler helping protocol

The following scheduler operations return a thread in need for help

  • unblock,
  • change priority, and
  • yield.

A thread in need for help is a thread that encounters a scheduler state
change from scheduled to ready or a thread that cannot be scheduled in
an unblock operation. Such a thread can ask threads which depend on
resources owned by this thread for help.

Add a new ask for help scheduler operation. This operation is used by
_Scheduler_Ask_for_help() to help threads in need for help returned by
the operations mentioned above. This operation is also used by
_Scheduler_Thread_change_resource_root() in case the root of a resource
sub-tree changes. A use case is the ownership change of a resource.

In case it is not possible to schedule a thread in need for help, then
the corresponding scheduler node will be placed into the set of ready
scheduler nodes of the scheduler instance. Once a state change from
ready to scheduled happens for this scheduler node it may be used to
schedule the thread in need for help.
  • Property mode set to 100644
File size: 861 bytes
Line 
1/*
2 *  @file
3 *
4 *  @brief Scheduler CBS Allocate
5 *  @ingroup ScoreScheduler
6 */
7
8/*
9 *  Copyright (C) 2011 Petr Benes.
10 *  Copyright (C) 2011 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.rtems.org/license/LICENSE.
15 */
16
17#if HAVE_CONFIG_H
18#include "config.h"
19#endif
20
21#include <rtems/score/schedulercbsimpl.h>
22
23void _Scheduler_CBS_Node_initialize(
24  const Scheduler_Control *scheduler,
25  Thread_Control          *the_thread
26)
27{
28  Scheduler_CBS_Node *node = _Scheduler_CBS_Thread_get_node( the_thread );
29
30  (void) scheduler;
31
32  _Scheduler_Node_do_initialize( &node->Base.Base, the_thread );
33
34  node->Base.thread = the_thread;
35  node->Base.queue_state = SCHEDULER_EDF_QUEUE_STATE_NEVER_HAS_BEEN;
36  node->cbs_server = NULL;
37}
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