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/**
* @file
*
* @brief Thread Dispatch Disable Functions
*
* @ingroup ScoreThread
*/
/*
* COPYRIGHT (c) 1989-2011.
* 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.
*/
#include <rtems/score/threaddispatch.h>
#include <rtems/score/assert.h>
#include <rtems/score/profiling.h>
#include <rtems/score/sysstate.h>
#define NO_OWNER_CPU NULL
typedef struct {
SMP_lock_Control lock;
Per_CPU_Control *owner_cpu;
uint32_t nest_level;
} Giant_Control;
static Giant_Control _Giant = {
.lock = SMP_LOCK_INITIALIZER("Giant"),
.owner_cpu = NO_OWNER_CPU,
.nest_level = 0
};
static void _Giant_Do_acquire( Per_CPU_Control *cpu_self )
{
Giant_Control *giant = &_Giant;
if ( giant->owner_cpu != cpu_self ) {
_SMP_lock_Acquire( &giant->lock, &cpu_self->Giant_lock_context );
giant->owner_cpu = cpu_self;
giant->nest_level = 1;
} else {
++giant->nest_level;
}
}
static void _Giant_Do_release( Per_CPU_Control *cpu_self )
{
Giant_Control *giant = &_Giant;
--giant->nest_level;
if ( giant->nest_level == 0 ) {
giant->owner_cpu = NO_OWNER_CPU;
_SMP_lock_Release( &giant->lock, &cpu_self->Giant_lock_context );
}
}
void _Giant_Drop( Per_CPU_Control *cpu_self )
{
Giant_Control *giant = &_Giant;
_Assert( _ISR_Get_level() != 0 );
if ( giant->owner_cpu == cpu_self ) {
giant->nest_level = 0;
giant->owner_cpu = NO_OWNER_CPU;
_SMP_lock_Release( &giant->lock, &cpu_self->Giant_lock_context );
}
}
uint32_t _Thread_Dispatch_increment_disable_level( void )
{
ISR_Level isr_level;
uint32_t disable_level;
Per_CPU_Control *cpu_self;
_ISR_Disable_without_giant( isr_level );
/*
* We must obtain the processor after interrupts are disabled to prevent
* thread migration.
*/
cpu_self = _Per_CPU_Get();
_Giant_Do_acquire( cpu_self );
disable_level = cpu_self->thread_dispatch_disable_level;
_Profiling_Thread_dispatch_disable( cpu_self, disable_level );
++disable_level;
cpu_self->thread_dispatch_disable_level = disable_level;
_ISR_Enable_without_giant( isr_level );
return disable_level;
}
uint32_t _Thread_Dispatch_decrement_disable_level( void )
{
ISR_Level isr_level;
uint32_t disable_level;
Per_CPU_Control *cpu_self;
_ISR_Disable_without_giant( isr_level );
cpu_self = _Per_CPU_Get();
disable_level = cpu_self->thread_dispatch_disable_level;
_Assert( disable_level > 0);
--disable_level;
cpu_self->thread_dispatch_disable_level = disable_level;
_Giant_Do_release( cpu_self );
_Profiling_Thread_dispatch_enable( cpu_self, disable_level );
_ISR_Enable_without_giant( isr_level );
return disable_level;
}
void _Giant_Acquire( Per_CPU_Control *cpu_self )
{
ISR_Level isr_level;
_ISR_Disable_without_giant( isr_level );
_Assert( _Thread_Dispatch_disable_level != 0 );
_Giant_Do_acquire( cpu_self );
_ISR_Enable_without_giant( isr_level );
}
void _Giant_Release( Per_CPU_Control *cpu_self )
{
ISR_Level isr_level;
_ISR_Disable_without_giant( isr_level );
_Assert( _Thread_Dispatch_disable_level != 0 );
_Giant_Do_release( cpu_self );
_ISR_Enable_without_giant( isr_level );
}
#if defined( RTEMS_DEBUG )
bool _Debug_Is_owner_of_giant( void )
{
Giant_Control *giant = &_Giant;
return giant->owner_cpu == _Per_CPU_Get_snapshot()
|| !_System_state_Is_up( _System_state_Get() );
}
#endif
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