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/**
* @file
*
* @brief Initialize a Core Mutex
* @ingroup ScoreMutex
*/
/*
* COPYRIGHT (c) 1989-1999.
* 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/system.h>
#include <rtems/score/isr.h>
#include <rtems/score/coremuteximpl.h>
#include <rtems/score/thread.h>
Status_Control _CORE_mutex_Initialize(
CORE_mutex_Control *the_mutex,
Thread_Control *executing,
const CORE_mutex_Attributes *the_mutex_attributes,
bool initially_locked
)
{
/* Add this to the RTEMS environment later ?????????
rtems_assert( initial_lock == CORE_MUTEX_LOCKED ||
initial_lock == CORE_MUTEX_UNLOCKED );
*/
the_mutex->Attributes = *the_mutex_attributes;
if ( initially_locked ) {
bool is_priority_ceiling;
Priority_Control ceiling;
Per_CPU_Control *cpu_self;
the_mutex->nest_count = 1;
the_mutex->holder = executing;
/* The mutex initialization is only protected by the allocator lock */
cpu_self = _Thread_Dispatch_disable();
is_priority_ceiling =
_CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes );
ceiling = the_mutex->Attributes.priority_ceiling;
/*
* The test to check for a ceiling violation is a bit arbitrary. In case
* this thread is the owner of a priority inheritance mutex, then it may
* get a higher priority later or anytime on SMP configurations.
*/
if ( is_priority_ceiling && executing->current_priority < ceiling ) {
/*
* There is no need to undo the previous work since this error aborts
* the object creation.
*/
_Thread_Dispatch_enable( cpu_self );
return STATUS_MUTEX_CEILING_VIOLATED;
}
executing->resource_count++;
if ( is_priority_ceiling ) {
_Thread_Raise_priority( executing, ceiling );
}
_Thread_Dispatch_enable( cpu_self );
} else {
the_mutex->nest_count = 0;
the_mutex->holder = NULL;
}
_Thread_queue_Initialize( &the_mutex->Wait_queue );
return STATUS_SUCCESSFUL;
}
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