/**
* @file
*
* @brief SMP Scheduler Implementation
*
* @ingroup ScoreSchedulerSMP
*/
/*
* Copyright (c) 2013, 2017 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* 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.
*/
#ifndef _RTEMS_SCORE_SCHEDULERSMPIMPL_H
#define _RTEMS_SCORE_SCHEDULERSMPIMPL_H
#include <rtems/score/schedulersmp.h>
#include <rtems/score/assert.h>
#include <rtems/score/chainimpl.h>
#include <rtems/score/schedulersimpleimpl.h>
#include <rtems/bspIo.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @addtogroup ScoreSchedulerSMP
*
* The scheduler nodes can be in four states
* - @ref SCHEDULER_SMP_NODE_BLOCKED,
* - @ref SCHEDULER_SMP_NODE_SCHEDULED, and
* - @ref SCHEDULER_SMP_NODE_READY.
*
* State transitions are triggered via basic operations
* - _Scheduler_SMP_Enqueue(),
* - _Scheduler_SMP_Enqueue_scheduled(), and
* - _Scheduler_SMP_Block().
*
* @dot
* digraph {
* node [style="filled"];
*
* bs [label="BLOCKED"];
* ss [label="SCHEDULED", fillcolor="green"];
* rs [label="READY", fillcolor="red"];
*
* edge [label="enqueue"];
* edge [fontcolor="darkgreen", color="darkgreen"];
*
* bs -> ss;
*
* edge [fontcolor="red", color="red"];
*
* bs -> rs;
*
* edge [label="enqueue other"];
*
* ss -> rs;
*
* edge [label="block"];
* edge [fontcolor="black", color="black"];
*
* ss -> bs;
* rs -> bs;
*
* edge [label="block other"];
* edge [fontcolor="darkgreen", color="darkgreen"];
*
* rs -> ss;
* }
* @enddot
*
* During system initialization each processor of the scheduler instance starts
* with an idle thread assigned to it. Lets have a look at an example with two
* idle threads I and J with priority 5. We also have blocked threads A, B and
* C with priorities 1, 2 and 3 respectively. The scheduler nodes are ordered
* with respect to the thread priority from left to right in the below
* diagrams. The highest priority node (lowest priority number) is the
* leftmost node. Since the processor assignment is independent of the thread
* priority the processor indices may move from one state to the other.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
* subgraph {
* rank = same;
*
* i [label="I (5)", fillcolor="green"];
* j [label="J (5)", fillcolor="green"];
* a [label="A (1)"];
* b [label="B (2)"];
* c [label="C (3)"];
* i -> j;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* i -> p0;
* j -> p1;
* }
* @enddot
*
* Lets start A. For this an enqueue operation is performed.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
*
* subgraph {
* rank = same;
*
* i [label="I (5)", fillcolor="green"];
* j [label="J (5)", fillcolor="red"];
* a [label="A (1)", fillcolor="green"];
* b [label="B (2)"];
* c [label="C (3)"];
* a -> i;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* i -> p0;
* a -> p1;
* }
* @enddot
*
* Lets start C.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
*
* subgraph {
* rank = same;
*
* a [label="A (1)", fillcolor="green"];
* c [label="C (3)", fillcolor="green"];
* i [label="I (5)", fillcolor="red"];
* j [label="J (5)", fillcolor="red"];
* b [label="B (2)"];
* a -> c;
* i -> j;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* c -> p0;
* a -> p1;
* }
* @enddot
*
* Lets start B.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
*
* subgraph {
* rank = same;
*
* a [label="A (1)", fillcolor="green"];
* b [label="B (2)", fillcolor="green"];
* c [label="C (3)", fillcolor="red"];
* i [label="I (5)", fillcolor="red"];
* j [label="J (5)", fillcolor="red"];
* a -> b;
* c -> i -> j;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* b -> p0;
* a -> p1;
* }
* @enddot
*
* Lets change the priority of thread A to 4.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
*
* subgraph {
* rank = same;
*
* b [label="B (2)", fillcolor="green"];
* c [label="C (3)", fillcolor="green"];
* a [label="A (4)", fillcolor="red"];
* i [label="I (5)", fillcolor="red"];
* j [label="J (5)", fillcolor="red"];
* b -> c;
* a -> i -> j;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* b -> p0;
* c -> p1;
* }
* @enddot
*
* Now perform a blocking operation with thread B. Please note that thread A
* migrated now from processor 0 to processor 1 and thread C still executes on
* processor 1.
*
* @dot
* digraph {
* node [style="filled"];
* edge [dir="none"];
*
* subgraph {
* rank = same;
*
* c [label="C (3)", fillcolor="green"];
* a [label="A (4)", fillcolor="green"];
* i [label="I (5)", fillcolor="red"];
* j [label="J (5)", fillcolor="red"];
* b [label="B (2)"];
* c -> a;
* i -> j;
* }
*
* subgraph {
* rank = same;
*
* p0 [label="PROCESSOR 0", shape="box"];
* p1 [label="PROCESSOR 1", shape="box"];
* }
*
* a -> p0;
* c -> p1;
* }
* @enddot
*
* @{
*/
typedef bool ( *Scheduler_SMP_Has_ready )(
Scheduler_Context *context
);
typedef Scheduler_Node *( *Scheduler_SMP_Get_highest_ready )(
Scheduler_Context *context,
Scheduler_Node *node
);
typedef Scheduler_Node *( *Scheduler_SMP_Get_lowest_scheduled )(
Scheduler_Context *context,
Scheduler_Node *filter
);
typedef void ( *Scheduler_SMP_Extract )(
Scheduler_Context *context,
Scheduler_Node *node_to_extract
);
typedef void ( *Scheduler_SMP_Insert )(
Scheduler_Context *context,
Scheduler_Node *node_to_insert,
Priority_Control insert_priority
);
typedef void ( *Scheduler_SMP_Move )(
Scheduler_Context *context,
Scheduler_Node *node_to_move
);
typedef bool ( *Scheduler_SMP_Ask_for_help )(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node
);
typedef void ( *Scheduler_SMP_Update )(
Scheduler_Context *context,
Scheduler_Node *node_to_update,
Priority_Control new_priority
);
typedef void ( *Scheduler_SMP_Set_affinity )(
Scheduler_Context *context,
Scheduler_Node *node,
void *arg
);
typedef bool ( *Scheduler_SMP_Enqueue )(
Scheduler_Context *context,
Scheduler_Node *node_to_enqueue,
Priority_Control priority
);
typedef void ( *Scheduler_SMP_Allocate_processor )(
Scheduler_Context *context,
Scheduler_Node *scheduled,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu
);
typedef void ( *Scheduler_SMP_Register_idle )(
Scheduler_Context *context,
Scheduler_Node *idle,
Per_CPU_Control *cpu
);
static inline void _Scheduler_SMP_Do_nothing_register_idle(
Scheduler_Context *context,
Scheduler_Node *idle,
Per_CPU_Control *cpu
)
{
(void) context;
(void) idle;
(void) cpu;
}
static inline bool _Scheduler_SMP_Priority_less_equal(
const void *to_insert,
const Chain_Node *next
)
{
const Priority_Control *priority_to_insert;
const Scheduler_SMP_Node *node_next;
priority_to_insert = (const Priority_Control *) to_insert;
node_next = (const Scheduler_SMP_Node *) next;
return *priority_to_insert <= node_next->priority;
}
static inline Scheduler_SMP_Context *_Scheduler_SMP_Get_self(
Scheduler_Context *context
)
{
return (Scheduler_SMP_Context *) context;
}
static inline void _Scheduler_SMP_Initialize(
Scheduler_SMP_Context *self
)
{
_Chain_Initialize_empty( &self->Scheduled );
_Chain_Initialize_empty( &self->Idle_threads );
}
static inline Scheduler_SMP_Node *_Scheduler_SMP_Thread_get_node(
Thread_Control *thread
)
{
return (Scheduler_SMP_Node *) _Thread_Scheduler_get_home_node( thread );
}
static inline Scheduler_SMP_Node *_Scheduler_SMP_Thread_get_own_node(
Thread_Control *thread
)
{
return (Scheduler_SMP_Node *) _Thread_Scheduler_get_home_node( thread );
}
static inline Scheduler_SMP_Node *_Scheduler_SMP_Node_downcast(
Scheduler_Node *node
)
{
return (Scheduler_SMP_Node *) node;
}
static inline Scheduler_SMP_Node_state _Scheduler_SMP_Node_state(
const Scheduler_Node *node
)
{
return ( (const Scheduler_SMP_Node *) node )->state;
}
static inline Priority_Control _Scheduler_SMP_Node_priority(
const Scheduler_Node *node
)
{
return ( (const Scheduler_SMP_Node *) node )->priority;
}
static inline void _Scheduler_SMP_Node_initialize(
const Scheduler_Control *scheduler,
Scheduler_SMP_Node *node,
Thread_Control *thread,
Priority_Control priority
)
{
_Scheduler_Node_do_initialize( scheduler, &node->Base, thread, priority );
node->state = SCHEDULER_SMP_NODE_BLOCKED;
node->priority = priority;
}
static inline void _Scheduler_SMP_Node_update_priority(
Scheduler_SMP_Node *node,
Priority_Control new_priority
)
{
node->priority = new_priority;
}
static inline void _Scheduler_SMP_Node_change_state(
Scheduler_Node *node,
Scheduler_SMP_Node_state new_state
)
{
Scheduler_SMP_Node *the_node;
the_node = _Scheduler_SMP_Node_downcast( node );
the_node->state = new_state;
}
static inline bool _Scheduler_SMP_Is_processor_owned_by_us(
const Scheduler_Context *context,
const Per_CPU_Control *cpu
)
{
return cpu->Scheduler.context == context;
}
static inline Thread_Control *_Scheduler_SMP_Get_idle_thread(
Scheduler_Context *context
)
{
Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context );
Thread_Control *idle = (Thread_Control *)
_Chain_Get_first_unprotected( &self->Idle_threads );
_Assert( &idle->Object.Node != _Chain_Tail( &self->Idle_threads ) );
return idle;
}
static inline void _Scheduler_SMP_Release_idle_thread(
Scheduler_Context *context,
Thread_Control *idle
)
{
Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context );
_Chain_Prepend_unprotected( &self->Idle_threads, &idle->Object.Node );
}
static inline void _Scheduler_SMP_Exctract_idle_thread(
Thread_Control *idle
)
{
_Chain_Extract_unprotected( &idle->Object.Node );
}
static inline void _Scheduler_SMP_Allocate_processor_lazy(
Scheduler_Context *context,
Scheduler_Node *scheduled,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu
)
{
Thread_Control *scheduled_thread = _Scheduler_Node_get_user( scheduled );
Thread_Control *victim_thread = _Scheduler_Node_get_user( victim );
Per_CPU_Control *scheduled_cpu = _Thread_Get_CPU( scheduled_thread );
Per_CPU_Control *cpu_self = _Per_CPU_Get();
Thread_Control *heir;
_Assert( _ISR_Get_level() != 0 );
if ( _Thread_Is_executing_on_a_processor( scheduled_thread ) ) {
if ( _Scheduler_SMP_Is_processor_owned_by_us( context, scheduled_cpu ) ) {
heir = scheduled_cpu->heir;
_Thread_Dispatch_update_heir(
cpu_self,
scheduled_cpu,
scheduled_thread
);
} else {
/* We have to force a migration to our processor set */
heir = scheduled_thread;
}
} else {
heir = scheduled_thread;
}
if ( heir != victim_thread ) {
_Thread_Set_CPU( heir, victim_cpu );
_Thread_Dispatch_update_heir( cpu_self, victim_cpu, heir );
}
}
/*
* This method is slightly different from
* _Scheduler_SMP_Allocate_processor_lazy() in that it does what it is asked to
* do. _Scheduler_SMP_Allocate_processor_lazy() attempts to prevent migrations
* but does not take into account affinity.
*/
static inline void _Scheduler_SMP_Allocate_processor_exact(
Scheduler_Context *context,
Scheduler_Node *scheduled,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu
)
{
Thread_Control *scheduled_thread = _Scheduler_Node_get_user( scheduled );
Per_CPU_Control *cpu_self = _Per_CPU_Get();
(void) context;
(void) victim;
_Thread_Set_CPU( scheduled_thread, victim_cpu );
_Thread_Dispatch_update_heir( cpu_self, victim_cpu, scheduled_thread );
}
static inline void _Scheduler_SMP_Allocate_processor(
Scheduler_Context *context,
Scheduler_Node *scheduled,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
_Scheduler_SMP_Node_change_state( scheduled, SCHEDULER_SMP_NODE_SCHEDULED );
( *allocate_processor )( context, scheduled, victim, victim_cpu );
}
static inline Thread_Control *_Scheduler_SMP_Preempt(
Scheduler_Context *context,
Scheduler_Node *scheduled,
Scheduler_Node *victim,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Thread_Control *victim_thread;
ISR_lock_Context lock_context;
Per_CPU_Control *victim_cpu;
victim_thread = _Scheduler_Node_get_user( victim );
_Scheduler_SMP_Node_change_state( victim, SCHEDULER_SMP_NODE_READY );
_Thread_Scheduler_acquire_critical( victim_thread, &lock_context );
victim_cpu = _Thread_Get_CPU( victim_thread );
if ( victim_thread->Scheduler.state == THREAD_SCHEDULER_SCHEDULED ) {
_Scheduler_Thread_change_state( victim_thread, THREAD_SCHEDULER_READY );
if ( victim_thread->Scheduler.helping_nodes > 0 ) {
_Per_CPU_Acquire( victim_cpu );
_Chain_Append_unprotected(
&victim_cpu->Threads_in_need_for_help,
&victim_thread->Scheduler.Help_node
);
_Per_CPU_Release( victim_cpu );
}
}
_Thread_Scheduler_release_critical( victim_thread, &lock_context );
_Scheduler_SMP_Allocate_processor(
context,
scheduled,
victim,
victim_cpu,
allocate_processor
);
return victim_thread;
}
static inline Scheduler_Node *_Scheduler_SMP_Get_lowest_scheduled(
Scheduler_Context *context,
Scheduler_Node *filter
)
{
Scheduler_SMP_Context *self = _Scheduler_SMP_Get_self( context );
Chain_Control *scheduled = &self->Scheduled;
Scheduler_Node *lowest_scheduled =
(Scheduler_Node *) _Chain_Last( scheduled );
(void) filter;
_Assert( &lowest_scheduled->Node.Chain != _Chain_Tail( scheduled ) );
_Assert(
_Chain_Next( &lowest_scheduled->Node.Chain ) == _Chain_Tail( scheduled )
);
return lowest_scheduled;
}
static inline void _Scheduler_SMP_Enqueue_to_scheduled(
Scheduler_Context *context,
Scheduler_Node *node,
Priority_Control priority,
Scheduler_Node *lowest_scheduled,
Scheduler_SMP_Insert insert_scheduled,
Scheduler_SMP_Move move_from_scheduled_to_ready,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_Try_to_schedule_action action;
action = _Scheduler_Try_to_schedule_node(
context,
node,
_Scheduler_Node_get_idle( lowest_scheduled ),
_Scheduler_SMP_Get_idle_thread
);
if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_SCHEDULE ) {
_Scheduler_SMP_Preempt(
context,
node,
lowest_scheduled,
allocate_processor
);
( *insert_scheduled )( context, node, priority );
( *move_from_scheduled_to_ready )( context, lowest_scheduled );
_Scheduler_Release_idle_thread(
context,
lowest_scheduled,
_Scheduler_SMP_Release_idle_thread
);
} else if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_IDLE_EXCHANGE ) {
_Scheduler_SMP_Node_change_state(
lowest_scheduled,
SCHEDULER_SMP_NODE_READY
);
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_SCHEDULED );
( *insert_scheduled )( context, node, priority );
( *move_from_scheduled_to_ready )( context, lowest_scheduled );
_Scheduler_Exchange_idle_thread(
node,
lowest_scheduled,
_Scheduler_Node_get_idle( lowest_scheduled )
);
} else {
_Assert( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_BLOCKED );
}
}
/**
* @brief Enqueues a node according to the specified order function.
*
* The node must not be in the scheduled state.
*
* @param[in] context The scheduler instance context.
* @param[in] node The node to enqueue.
* @param[in] priority The node insert priority.
* @param[in] order The order function.
* @param[in] insert_ready Function to insert a node into the set of ready
* nodes.
* @param[in] insert_scheduled Function to insert a node into the set of
* scheduled nodes.
* @param[in] move_from_scheduled_to_ready Function to move a node from the set
* of scheduled nodes to the set of ready nodes.
* @param[in] get_lowest_scheduled Function to select the node from the
* scheduled nodes to replace. It may not be possible to find one, in this
* case a pointer must be returned so that the order functions returns false
* if this pointer is passed as the second argument to the order function.
* @param[in] allocate_processor Function to allocate a processor to a node
* based on the rules of the scheduler.
*/
static inline bool _Scheduler_SMP_Enqueue(
Scheduler_Context *context,
Scheduler_Node *node,
Priority_Control insert_priority,
Chain_Node_order order,
Scheduler_SMP_Insert insert_ready,
Scheduler_SMP_Insert insert_scheduled,
Scheduler_SMP_Move move_from_scheduled_to_ready,
Scheduler_SMP_Get_lowest_scheduled get_lowest_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
bool needs_help;
Scheduler_Node *lowest_scheduled;
lowest_scheduled = ( *get_lowest_scheduled )( context, node );
if ( ( *order )( &insert_priority, &lowest_scheduled->Node.Chain ) ) {
_Scheduler_SMP_Enqueue_to_scheduled(
context,
node,
insert_priority,
lowest_scheduled,
insert_scheduled,
move_from_scheduled_to_ready,
allocate_processor
);
needs_help = false;
} else {
( *insert_ready )( context, node, insert_priority );
needs_help = true;
}
return needs_help;
}
/**
* @brief Enqueues a scheduled node according to the specified order
* function.
*
* @param[in] context The scheduler instance context.
* @param[in] node The node to enqueue.
* @param[in] order The order function.
* @param[in] extract_from_ready Function to extract a node from the set of
* ready nodes.
* @param[in] get_highest_ready Function to get the highest ready node.
* @param[in] insert_ready Function to insert a node into the set of ready
* nodes.
* @param[in] insert_scheduled Function to insert a node into the set of
* scheduled nodes.
* @param[in] move_from_ready_to_scheduled Function to move a node from the set
* of ready nodes to the set of scheduled nodes.
* @param[in] allocate_processor Function to allocate a processor to a node
* based on the rules of the scheduler.
*/
static inline bool _Scheduler_SMP_Enqueue_scheduled(
Scheduler_Context *context,
Scheduler_Node *const node,
Priority_Control insert_priority,
Chain_Node_order order,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Insert insert_ready,
Scheduler_SMP_Insert insert_scheduled,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
while ( true ) {
Scheduler_Node *highest_ready;
Scheduler_Try_to_schedule_action action;
highest_ready = ( *get_highest_ready )( context, node );
/*
* The node has been extracted from the scheduled chain. We have to place
* it now on the scheduled or ready set.
*/
if (
node->sticky_level > 0
&& ( *order )( &insert_priority, &highest_ready->Node.Chain )
) {
( *insert_scheduled )( context, node, insert_priority );
if ( _Scheduler_Node_get_idle( node ) != NULL ) {
Thread_Control *owner;
ISR_lock_Context lock_context;
owner = _Scheduler_Node_get_owner( node );
_Thread_Scheduler_acquire_critical( owner, &lock_context );
if ( owner->Scheduler.state == THREAD_SCHEDULER_READY ) {
_Thread_Scheduler_cancel_need_for_help(
owner,
_Thread_Get_CPU( owner )
);
_Scheduler_Discard_idle_thread(
context,
owner,
node,
_Scheduler_SMP_Release_idle_thread
);
_Scheduler_Thread_change_state( owner, THREAD_SCHEDULER_SCHEDULED );
}
_Thread_Scheduler_release_critical( owner, &lock_context );
}
return false;
}
action = _Scheduler_Try_to_schedule_node(
context,
highest_ready,
_Scheduler_Node_get_idle( node ),
_Scheduler_SMP_Get_idle_thread
);
if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_SCHEDULE ) {
Thread_Control *idle;
_Scheduler_SMP_Preempt(
context,
highest_ready,
node,
allocate_processor
);
( *insert_ready )( context, node, insert_priority );
( *move_from_ready_to_scheduled )( context, highest_ready );
idle = _Scheduler_Release_idle_thread(
context,
node,
_Scheduler_SMP_Release_idle_thread
);
return ( idle == NULL );
} else if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_IDLE_EXCHANGE ) {
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_READY );
_Scheduler_SMP_Node_change_state(
highest_ready,
SCHEDULER_SMP_NODE_SCHEDULED
);
( *insert_ready )( context, node, insert_priority );
( *move_from_ready_to_scheduled )( context, highest_ready );
_Scheduler_Exchange_idle_thread(
highest_ready,
node,
_Scheduler_Node_get_idle( node )
);
return false;
} else {
_Assert( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
_Scheduler_SMP_Node_change_state(
highest_ready,
SCHEDULER_SMP_NODE_BLOCKED
);
( *extract_from_ready )( context, highest_ready );
}
}
}
static inline void _Scheduler_SMP_Extract_from_scheduled(
Scheduler_Node *node
)
{
_Chain_Extract_unprotected( &node->Node.Chain );
}
static inline void _Scheduler_SMP_Schedule_highest_ready(
Scheduler_Context *context,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_Try_to_schedule_action action;
do {
Scheduler_Node *highest_ready = ( *get_highest_ready )( context, victim );
action = _Scheduler_Try_to_schedule_node(
context,
highest_ready,
NULL,
_Scheduler_SMP_Get_idle_thread
);
if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_SCHEDULE ) {
_Scheduler_SMP_Allocate_processor(
context,
highest_ready,
victim,
victim_cpu,
allocate_processor
);
( *move_from_ready_to_scheduled )( context, highest_ready );
} else {
_Assert( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
_Scheduler_SMP_Node_change_state(
highest_ready,
SCHEDULER_SMP_NODE_BLOCKED
);
( *extract_from_ready )( context, highest_ready );
}
} while ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
}
static inline void _Scheduler_SMP_Preempt_and_schedule_highest_ready(
Scheduler_Context *context,
Scheduler_Node *victim,
Per_CPU_Control *victim_cpu,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_Try_to_schedule_action action;
do {
Scheduler_Node *highest_ready = ( *get_highest_ready )( context, victim );
action = _Scheduler_Try_to_schedule_node(
context,
highest_ready,
NULL,
_Scheduler_SMP_Get_idle_thread
);
if ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_SCHEDULE ) {
_Scheduler_SMP_Preempt(
context,
highest_ready,
victim,
allocate_processor
);
( *move_from_ready_to_scheduled )( context, highest_ready );
} else {
_Assert( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
_Scheduler_SMP_Node_change_state(
highest_ready,
SCHEDULER_SMP_NODE_BLOCKED
);
( *extract_from_ready )( context, highest_ready );
}
} while ( action == SCHEDULER_TRY_TO_SCHEDULE_DO_BLOCK );
}
/**
* @brief Blocks a thread.
*
* @param[in] context The scheduler instance context.
* @param[in] thread The thread of the scheduling operation.
* @param[in] node The scheduler node of the thread to block.
* @param[in] extract_from_ready Function to extract a node from the set of
* ready nodes.
* @param[in] get_highest_ready Function to get the highest ready node.
* @param[in] move_from_ready_to_scheduled Function to move a node from the set
* of ready nodes to the set of scheduled nodes.
*/
static inline void _Scheduler_SMP_Block(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_SMP_Node_state node_state;
Per_CPU_Control *thread_cpu;
node_state = _Scheduler_SMP_Node_state( node );
thread_cpu = _Scheduler_Block_node(
context,
thread,
node,
node_state == SCHEDULER_SMP_NODE_SCHEDULED,
_Scheduler_SMP_Get_idle_thread
);
if ( thread_cpu != NULL ) {
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_BLOCKED );
if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
_Scheduler_SMP_Extract_from_scheduled( node );
_Scheduler_SMP_Schedule_highest_ready(
context,
node,
thread_cpu,
extract_from_ready,
get_highest_ready,
move_from_ready_to_scheduled,
allocate_processor
);
} else if ( node_state == SCHEDULER_SMP_NODE_READY ) {
( *extract_from_ready )( context, node );
}
}
}
static inline void _Scheduler_SMP_Unblock(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Scheduler_SMP_Update update,
Scheduler_SMP_Enqueue enqueue
)
{
Scheduler_SMP_Node_state node_state;
bool unblock;
node_state = _Scheduler_SMP_Node_state( node );
unblock = _Scheduler_Unblock_node(
context,
thread,
node,
node_state == SCHEDULER_SMP_NODE_SCHEDULED,
_Scheduler_SMP_Release_idle_thread
);
if ( unblock ) {
Priority_Control priority;
bool needs_help;
priority = _Scheduler_Node_get_priority( node );
priority = SCHEDULER_PRIORITY_PURIFY( priority );
if ( priority != _Scheduler_SMP_Node_priority( node ) ) {
( *update )( context, node, priority );
}
if ( node_state == SCHEDULER_SMP_NODE_BLOCKED ) {
Priority_Control insert_priority;
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_READY );
insert_priority = SCHEDULER_PRIORITY_APPEND( priority );
needs_help = ( *enqueue )( context, node, insert_priority );
} else {
_Assert( node_state == SCHEDULER_SMP_NODE_READY );
_Assert( node->sticky_level > 0 );
_Assert( node->idle == NULL );
needs_help = true;
}
if ( needs_help ) {
_Scheduler_Ask_for_help( thread );
}
}
}
static inline void _Scheduler_SMP_Update_priority(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Update update,
Scheduler_SMP_Enqueue enqueue,
Scheduler_SMP_Enqueue enqueue_scheduled,
Scheduler_SMP_Ask_for_help ask_for_help
)
{
Priority_Control priority;
Priority_Control insert_priority;
Scheduler_SMP_Node_state node_state;
insert_priority = _Scheduler_Node_get_priority( node );
priority = SCHEDULER_PRIORITY_PURIFY( insert_priority );
if ( priority == _Scheduler_SMP_Node_priority( node ) ) {
if ( _Thread_Is_ready( thread ) ) {
( *ask_for_help )( context, thread, node );
}
return;
}
node_state = _Scheduler_SMP_Node_state( node );
if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
_Scheduler_SMP_Extract_from_scheduled( node );
( *update )( context, node, priority );
( *enqueue_scheduled )( context, node, insert_priority );
} else if ( node_state == SCHEDULER_SMP_NODE_READY ) {
( *extract_from_ready )( context, node );
( *update )( context, node, priority );
( *enqueue )( context, node, insert_priority );
} else {
( *update )( context, node, priority );
if ( _Thread_Is_ready( thread ) ) {
( *ask_for_help )( context, thread, node );
}
}
}
static inline void _Scheduler_SMP_Yield(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Enqueue enqueue,
Scheduler_SMP_Enqueue enqueue_scheduled
)
{
bool needs_help;
Scheduler_SMP_Node_state node_state;
Priority_Control insert_priority;
node_state = _Scheduler_SMP_Node_state( node );
insert_priority = _Scheduler_SMP_Node_priority( node );
insert_priority = SCHEDULER_PRIORITY_APPEND( insert_priority );
if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
_Scheduler_SMP_Extract_from_scheduled( node );
( *enqueue_scheduled )( context, node, insert_priority );
needs_help = false;
} else if ( node_state == SCHEDULER_SMP_NODE_READY ) {
( *extract_from_ready )( context, node );
needs_help = ( *enqueue )( context, node, insert_priority );
} else {
needs_help = true;
}
if ( needs_help ) {
_Scheduler_Ask_for_help( thread );
}
}
static inline void _Scheduler_SMP_Insert_scheduled(
Scheduler_Context *context,
Scheduler_Node *node_to_insert,
Priority_Control priority_to_insert
)
{
Scheduler_SMP_Context *self;
self = _Scheduler_SMP_Get_self( context );
_Chain_Insert_ordered_unprotected(
&self->Scheduled,
&node_to_insert->Node.Chain,
&priority_to_insert,
_Scheduler_SMP_Priority_less_equal
);
}
static inline bool _Scheduler_SMP_Ask_for_help(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Chain_Node_order order,
Scheduler_SMP_Insert insert_ready,
Scheduler_SMP_Insert insert_scheduled,
Scheduler_SMP_Move move_from_scheduled_to_ready,
Scheduler_SMP_Get_lowest_scheduled get_lowest_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_Node *lowest_scheduled;
ISR_lock_Context lock_context;
bool success;
lowest_scheduled = ( *get_lowest_scheduled )( context, node );
_Thread_Scheduler_acquire_critical( thread, &lock_context );
if ( thread->Scheduler.state == THREAD_SCHEDULER_READY ) {
Scheduler_SMP_Node_state node_state;
node_state = _Scheduler_SMP_Node_state( node );
if ( node_state == SCHEDULER_SMP_NODE_BLOCKED ) {
Priority_Control insert_priority;
insert_priority = _Scheduler_SMP_Node_priority( node );
if ( ( *order )( &insert_priority, &lowest_scheduled->Node.Chain ) ) {
_Thread_Scheduler_cancel_need_for_help(
thread,
_Thread_Get_CPU( thread )
);
_Scheduler_Thread_change_state( thread, THREAD_SCHEDULER_SCHEDULED );
_Thread_Scheduler_release_critical( thread, &lock_context );
_Scheduler_SMP_Preempt(
context,
node,
lowest_scheduled,
allocate_processor
);
( *insert_scheduled )( context, node, insert_priority );
( *move_from_scheduled_to_ready )( context, lowest_scheduled );
_Scheduler_Release_idle_thread(
context,
lowest_scheduled,
_Scheduler_SMP_Release_idle_thread
);
success = true;
} else {
_Thread_Scheduler_release_critical( thread, &lock_context );
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_READY );
( *insert_ready )( context, node, insert_priority );
success = false;
}
} else if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
_Thread_Scheduler_cancel_need_for_help(
thread,
_Thread_Get_CPU( thread )
);
_Scheduler_Discard_idle_thread(
context,
thread,
node,
_Scheduler_SMP_Release_idle_thread
);
_Scheduler_Thread_change_state( thread, THREAD_SCHEDULER_SCHEDULED );
_Thread_Scheduler_release_critical( thread, &lock_context );
success = true;
} else {
_Thread_Scheduler_release_critical( thread, &lock_context );
success = false;
}
} else {
_Thread_Scheduler_release_critical( thread, &lock_context );
success = false;
}
return success;
}
static inline void _Scheduler_SMP_Reconsider_help_request(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Scheduler_SMP_Extract extract_from_ready
)
{
ISR_lock_Context lock_context;
_Thread_Scheduler_acquire_critical( thread, &lock_context );
if (
thread->Scheduler.state == THREAD_SCHEDULER_SCHEDULED
&& _Scheduler_SMP_Node_state( node ) == SCHEDULER_SMP_NODE_READY
&& node->sticky_level == 1
) {
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_BLOCKED );
( *extract_from_ready )( context, node );
}
_Thread_Scheduler_release_critical( thread, &lock_context );
}
static inline void _Scheduler_SMP_Withdraw_node(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
Thread_Scheduler_state next_state,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
ISR_lock_Context lock_context;
Scheduler_SMP_Node_state node_state;
_Thread_Scheduler_acquire_critical( thread, &lock_context );
node_state = _Scheduler_SMP_Node_state( node );
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_BLOCKED );
if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
Per_CPU_Control *thread_cpu;
thread_cpu = _Thread_Get_CPU( thread );
_Scheduler_Thread_change_state( thread, next_state );
_Thread_Scheduler_release_critical( thread, &lock_context );
_Scheduler_SMP_Extract_from_scheduled( node );
_Scheduler_SMP_Schedule_highest_ready(
context,
node,
thread_cpu,
extract_from_ready,
get_highest_ready,
move_from_ready_to_scheduled,
allocate_processor
);
} else if ( node_state == SCHEDULER_SMP_NODE_READY ) {
_Thread_Scheduler_release_critical( thread, &lock_context );
( *extract_from_ready )( context, node );
} else {
_Assert( node_state == SCHEDULER_SMP_NODE_BLOCKED );
_Thread_Scheduler_release_critical( thread, &lock_context );
}
}
static inline void _Scheduler_SMP_Do_start_idle(
Scheduler_Context *context,
Thread_Control *idle,
Per_CPU_Control *cpu,
Scheduler_SMP_Register_idle register_idle
)
{
Scheduler_SMP_Context *self;
Scheduler_SMP_Node *node;
self = _Scheduler_SMP_Get_self( context );
node = _Scheduler_SMP_Thread_get_node( idle );
_Scheduler_Thread_change_state( idle, THREAD_SCHEDULER_SCHEDULED );
node->state = SCHEDULER_SMP_NODE_SCHEDULED;
_Thread_Set_CPU( idle, cpu );
( *register_idle )( context, &node->Base, cpu );
_Chain_Append_unprotected( &self->Scheduled, &node->Base.Node.Chain );
_Scheduler_SMP_Release_idle_thread( &self->Base, idle );
}
static inline void _Scheduler_SMP_Add_processor(
Scheduler_Context *context,
Thread_Control *idle,
Scheduler_SMP_Has_ready has_ready,
Scheduler_SMP_Enqueue enqueue_scheduled,
Scheduler_SMP_Register_idle register_idle
)
{
Scheduler_SMP_Context *self;
Scheduler_Node *node;
self = _Scheduler_SMP_Get_self( context );
idle->Scheduler.state = THREAD_SCHEDULER_SCHEDULED;
_Scheduler_SMP_Release_idle_thread( &self->Base, idle );
node = _Thread_Scheduler_get_home_node( idle );
_Scheduler_SMP_Node_change_state( node, SCHEDULER_SMP_NODE_SCHEDULED );
( *register_idle )( context, node, _Thread_Get_CPU( idle ) );
if ( ( *has_ready )( &self->Base ) ) {
Priority_Control insert_priority;
insert_priority = _Scheduler_SMP_Node_priority( node );
insert_priority = SCHEDULER_PRIORITY_APPEND( insert_priority );
( *enqueue_scheduled )( &self->Base, node, insert_priority );
} else {
_Chain_Append_unprotected( &self->Scheduled, &node->Node.Chain );
}
}
static inline Thread_Control *_Scheduler_SMP_Remove_processor(
Scheduler_Context *context,
Per_CPU_Control *cpu,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Enqueue enqueue
)
{
Scheduler_SMP_Context *self;
Chain_Node *chain_node;
Scheduler_Node *victim_node;
Thread_Control *victim_user;
Thread_Control *victim_owner;
Thread_Control *idle;
self = _Scheduler_SMP_Get_self( context );
chain_node = _Chain_First( &self->Scheduled );
do {
_Assert( chain_node != _Chain_Immutable_tail( &self->Scheduled ) );
victim_node = (Scheduler_Node *) chain_node;
victim_user = _Scheduler_Node_get_user( victim_node );
chain_node = _Chain_Next( chain_node );
} while ( _Thread_Get_CPU( victim_user ) != cpu );
_Scheduler_SMP_Extract_from_scheduled( victim_node );
victim_owner = _Scheduler_Node_get_owner( victim_node );
if ( !victim_owner->is_idle ) {
Scheduler_Node *idle_node;
_Scheduler_Release_idle_thread(
&self->Base,
victim_node,
_Scheduler_SMP_Release_idle_thread
);
idle = _Scheduler_SMP_Get_idle_thread( &self->Base );
idle_node = _Thread_Scheduler_get_home_node( idle );
( *extract_from_ready )( &self->Base, idle_node );
_Scheduler_SMP_Preempt(
&self->Base,
idle_node,
victim_node,
_Scheduler_SMP_Allocate_processor_exact
);
if ( !_Chain_Is_empty( &self->Scheduled ) ) {
Priority_Control insert_priority;
insert_priority = _Scheduler_SMP_Node_priority( victim_node );
insert_priority = SCHEDULER_PRIORITY_APPEND( insert_priority );
( *enqueue )( context, victim_node, insert_priority );
}
} else {
_Assert( victim_owner == victim_user );
_Assert( _Scheduler_Node_get_idle( victim_node ) == NULL );
idle = victim_owner;
_Scheduler_SMP_Exctract_idle_thread( idle );
}
return idle;
}
static inline void _Scheduler_SMP_Set_affinity(
Scheduler_Context *context,
Thread_Control *thread,
Scheduler_Node *node,
void *arg,
Scheduler_SMP_Set_affinity set_affinity,
Scheduler_SMP_Extract extract_from_ready,
Scheduler_SMP_Get_highest_ready get_highest_ready,
Scheduler_SMP_Move move_from_ready_to_scheduled,
Scheduler_SMP_Enqueue enqueue,
Scheduler_SMP_Allocate_processor allocate_processor
)
{
Scheduler_SMP_Node_state node_state;
Priority_Control insert_priority;
node_state = _Scheduler_SMP_Node_state( node );
insert_priority = _Scheduler_SMP_Node_priority( node );
insert_priority = SCHEDULER_PRIORITY_APPEND( insert_priority );
if ( node_state == SCHEDULER_SMP_NODE_SCHEDULED ) {
_Scheduler_SMP_Extract_from_scheduled( node );
_Scheduler_SMP_Preempt_and_schedule_highest_ready(
context,
node,
_Thread_Get_CPU( thread ),
extract_from_ready,
get_highest_ready,
move_from_ready_to_scheduled,
allocate_processor
);
( *set_affinity )( context, node, arg );
( *enqueue )( context, node, insert_priority );
} else if ( node_state == SCHEDULER_SMP_NODE_READY ) {
( *extract_from_ready )( context, node );
( *set_affinity )( context, node, arg );
( *enqueue )( context, node, insert_priority );
} else {
( *set_affinity )( context, node, arg );
}
}
/** @} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _RTEMS_SCORE_SCHEDULERSMPIMPL_H */