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/**
* @file
*
* @brief RTEMS Get Region Segment
* @ingroup ClassicRegion
*/
/*
* COPYRIGHT (c) 1989-2007.
* 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/rtems/regionimpl.h>
#include <rtems/rtems/optionsimpl.h>
#include <rtems/rtems/statusimpl.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/score/statesimpl.h>
rtems_status_code rtems_region_get_segment(
rtems_id id,
uintptr_t size,
rtems_option option_set,
rtems_interval timeout,
void **segment
)
{
rtems_status_code status;
Region_Control *the_region;
if ( segment == NULL ) {
return RTEMS_INVALID_ADDRESS;
}
*segment = NULL;
if ( size == 0 ) {
return RTEMS_INVALID_SIZE;
}
the_region = _Region_Get_and_lock( id );
if ( the_region == NULL ) {
return RTEMS_INVALID_ID;
}
if ( size > the_region->maximum_segment_size ) {
status = RTEMS_INVALID_SIZE;
} else {
void *the_segment;
the_segment = _Region_Allocate_segment( the_region, size );
if ( the_segment != NULL ) {
*segment = the_segment;
status = RTEMS_SUCCESSFUL;
} else if ( _Options_Is_no_wait( option_set ) ) {
status = RTEMS_UNSATISFIED;
} else {
Per_CPU_Control *cpu_self;
Thread_Control *executing;
/*
* Switch from using the memory allocation mutex to using a
* dispatching disabled critical section. We have to do this
* because this thread is going to block.
*/
/* FIXME: This is a home grown condition variable */
cpu_self = _Thread_Dispatch_disable();
_Region_Unlock( the_region );
executing = _Per_CPU_Get_executing( cpu_self );
executing->Wait.count = size;
executing->Wait.return_argument = segment;
_Thread_queue_Enqueue(
&the_region->Wait_queue,
the_region->wait_operations,
executing,
STATES_WAITING_FOR_SEGMENT,
timeout,
2
);
_Thread_Dispatch_enable( cpu_self );
return _Status_Get_after_wait( executing );
}
}
_Region_Unlock( the_region );
return status;
}
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