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/**
* @file
*
* @brief Thread Queue Dequeue Priority
* @ingroup ScoreThreadQ
*/
/*
* COPYRIGHT (c) 1989-2008.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/threadqimpl.h>
#include <rtems/score/chainimpl.h>
#include <rtems/score/isrlevel.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/watchdogimpl.h>
Thread_Control *_Thread_queue_Dequeue_priority(
Thread_queue_Control *the_thread_queue
)
{
uint32_t index;
ISR_Level level;
Thread_Control *the_thread = NULL; /* just to remove warnings */
Thread_Control *new_first_thread;
Chain_Node *head;
Chain_Node *tail;
Chain_Node *new_first_node;
Chain_Node *new_second_node;
Chain_Node *last_node;
Chain_Node *next_node;
Chain_Node *previous_node;
_ISR_Disable( level );
for( index=0 ;
index < TASK_QUEUE_DATA_NUMBER_OF_PRIORITY_HEADERS ;
index++ ) {
if ( !_Chain_Is_empty( &the_thread_queue->Queues.Priority[ index ] ) ) {
the_thread = (Thread_Control *) _Chain_First(
&the_thread_queue->Queues.Priority[ index ]
);
goto dequeue;
}
}
/*
* We did not find a thread to unblock.
*/
_ISR_Enable( level );
return NULL;
dequeue:
the_thread->Wait.queue = NULL;
new_first_node = _Chain_First( &the_thread->Wait.Block2n );
new_first_thread = (Thread_Control *) new_first_node;
next_node = the_thread->Object.Node.next;
previous_node = the_thread->Object.Node.previous;
if ( !_Chain_Is_empty( &the_thread->Wait.Block2n ) ) {
last_node = _Chain_Last( &the_thread->Wait.Block2n );
new_second_node = new_first_node->next;
previous_node->next = new_first_node;
next_node->previous = new_first_node;
new_first_node->next = next_node;
new_first_node->previous = previous_node;
if ( !_Chain_Has_only_one_node( &the_thread->Wait.Block2n ) ) {
/* > two threads on 2-n */
head = _Chain_Head( &new_first_thread->Wait.Block2n );
tail = _Chain_Tail( &new_first_thread->Wait.Block2n );
new_second_node->previous = head;
head->next = new_second_node;
tail->previous = last_node;
last_node->next = tail;
}
} else {
previous_node->next = next_node;
next_node->previous = previous_node;
}
if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
_ISR_Enable( level );
} else {
_Watchdog_Deactivate( &the_thread->Timer );
_ISR_Enable( level );
(void) _Watchdog_Remove( &the_thread->Timer );
}
_Thread_Unblock( the_thread );
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
_Thread_MP_Free_proxy( the_thread );
#endif
return( the_thread );
}
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