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/*
* Thread Queue Handler - Process Timeout Handler
*
*
* 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.com/license/LICENSE.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/system.h>
#include <rtems/score/chain.h>
#include <rtems/score/isr.h>
#include <rtems/score/object.h>
#include <rtems/score/states.h>
#include <rtems/score/thread.h>
#include <rtems/score/threadq.h>
#include <rtems/score/tqdata.h>
void _Thread_queue_Process_timeout(
Thread_Control *the_thread
)
{
Thread_queue_Control *the_thread_queue;
ISR_Level level;
/*
* If the_thread_queue is not synchronized, then it is either
* "nothing happened", "timeout", or "satisfied". If the_thread
* is the executing thread, then it is in the process of blocking
* and it is the thread which is responsible for the synchronization
* process.
*
* If it is not satisfied, then it is "nothing happened" and
* this is the "timeout" transition. After a request is satisfied,
* a timeout is not allowed to occur.
*/
_ISR_Disable( level );
the_thread_queue = the_thread->Wait.queue;
if ( the_thread_queue != NULL ) {
if ( the_thread_queue->sync_state != THREAD_BLOCKING_OPERATION_SYNCHRONIZED &&
_Thread_Is_executing( the_thread ) ) {
if ( the_thread_queue->sync_state != THREAD_BLOCKING_OPERATION_SATISFIED ) {
the_thread->Wait.return_code = the_thread_queue->timeout_status;
the_thread_queue->sync_state = THREAD_BLOCKING_OPERATION_TIMEOUT;
}
_ISR_Enable( level );
} else {
bool we_did_it;
_ISR_Enable( level );
/*
* After we enable interrupts here, a lot may happen in the meantime,
* e.g. nested interrupts may release the resource that times out here.
* So we enter _Thread_queue_Extract() speculatively. Inside this
* function we check the actual status under ISR disable protection.
* This ensures that exactly one executing context performs the extract
* operation (other parties may call _Thread_queue_Dequeue()). If this
* context won, then we have a timeout.
*
* We can use the_thread_queue pointer here even if
* the_thread->Wait.queue is already set to NULL since the extract
* operation will only use the thread queue discipline to select the
* right extract operation. The timeout status is set during thread
* queue initialization.
*/
we_did_it = _Thread_queue_Extract( the_thread_queue, the_thread );
if ( we_did_it ) {
the_thread->Wait.return_code = the_thread_queue->timeout_status;
}
}
} else {
_ISR_Enable( level );
}
}
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