source: rtems/cpukit/score/src/corebarrierwait.c @ 620b23e

5
Last change on this file since 620b23e was 620b23e, checked in by Sebastian Huber <sebastian.huber@…>, on 11/24/16 at 05:13:11

score: Optimize _Thread_queue_Enqueue()

Move thread state for _Thread_queue_Enqueue() to the thread queue
context. This reduces the parameter count of _Thread_queue_Enqueue()
from five to four (ARM for example has only four function parameter
registers). Since the thread state is used after several function calls
inside _Thread_queue_Enqueue() this parameter was saved on the stack
previously.

  • Property mode set to 100644
File size: 1.6 KB
Line 
1/**
2 *  @file
3 *
4 *  @brief Wait For The Barrier
5 *  @ingroup ScoreBarrier
6 */
7
8/*
9 *  COPYRIGHT (c) 1989-2006.
10 *  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/corebarrierimpl.h>
22#include <rtems/score/statesimpl.h>
23#include <rtems/score/threadimpl.h>
24
25Status_Control _CORE_barrier_Seize(
26  CORE_barrier_Control *the_barrier,
27  Thread_Control       *executing,
28  bool                  wait,
29  Thread_queue_Context *queue_context
30)
31{
32  uint32_t number_of_waiting_threads;
33
34  _CORE_barrier_Acquire_critical( the_barrier, queue_context );
35
36  number_of_waiting_threads = the_barrier->number_of_waiting_threads;
37  ++number_of_waiting_threads;
38
39  if (
40    _CORE_barrier_Is_automatic( &the_barrier->Attributes )
41      && number_of_waiting_threads == the_barrier->Attributes.maximum_count
42  ) {
43    _CORE_barrier_Surrender( the_barrier, queue_context );
44    return STATUS_BARRIER_AUTOMATICALLY_RELEASED;
45  } else {
46    the_barrier->number_of_waiting_threads = number_of_waiting_threads;
47    _Thread_queue_Context_set_thread_state(
48      queue_context,
49      STATES_WAITING_FOR_BARRIER
50    );
51    _Thread_queue_Context_set_do_nothing_enqueue_callout( queue_context );
52    _Thread_queue_Enqueue(
53      &the_barrier->Wait_queue.Queue,
54      CORE_BARRIER_TQ_OPERATIONS,
55      executing,
56      queue_context
57    );
58    return _Thread_Wait_get_status( executing );
59  }
60}
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