diff options
Diffstat (limited to '')
| -rw-r--r-- | cpukit/score/include/rtems/score/schedulerimpl.h | 133 |
1 files changed, 78 insertions, 55 deletions
diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h index edad0d3fd4..11347fe047 100644 --- a/cpukit/score/include/rtems/score/schedulerimpl.h +++ b/cpukit/score/include/rtems/score/schedulerimpl.h @@ -341,12 +341,12 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Block( Thread_Control *the_thread ) /** * @brief Unblocks a thread with respect to the scheduler. * - * This routine adds @a the_thread to the scheduling decision for - * the scheduler. The primary task is to add the thread to the - * ready queue per the schedulering policy and update any appropriate - * scheduling variables, for example the heir thread. + * This operation must fetch the latest thread priority value for this + * scheduler instance and update its internal state if necessary. * * @param[in] the_thread The thread. + * + * @see _Scheduler_Node_get_priority(). */ RTEMS_INLINE_ROUTINE void _Scheduler_Unblock( Thread_Control *the_thread ) { @@ -374,24 +374,18 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Unblock( Thread_Control *the_thread ) /** * @brief Propagates a priority change of a thread to the scheduler. * - * The caller must ensure that the thread is in the ready state. The caller - * must ensure that the priority value actually changed and is not equal to the - * current priority value. + * On uni-processor configurations, this operation must evaluate the thread + * state. In case the thread is not ready, then the priority update should be + * deferred to the next scheduler unblock operation. * * The operation must update the heir and thread dispatch necessary variables * in case the set of scheduled threads changes. * * @param[in] the_thread The thread changing its priority. - * @param[in] new_priority The new thread priority. - * @param[in] prepend_it In case this is true, then enqueue the thread as the - * first of its priority group, otherwise enqueue the thread as the last of its - * priority group. + * + * @see _Scheduler_Node_get_priority(). */ -RTEMS_INLINE_ROUTINE void _Scheduler_Change_priority( - Thread_Control *the_thread, - Priority_Control new_priority, - bool prepend_it -) +RTEMS_INLINE_ROUTINE void _Scheduler_Update_priority( Thread_Control *the_thread ) { const Scheduler_Control *own_scheduler; ISR_lock_Context lock_context; @@ -405,12 +399,7 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Change_priority( #if defined(RTEMS_SMP) needs_help = #endif - ( *own_scheduler->Operations.change_priority )( - own_scheduler, - the_thread, - new_priority, - prepend_it - ); + ( *own_scheduler->Operations.update_priority )( own_scheduler, the_thread ); #if defined(RTEMS_SMP) _Scheduler_Ask_for_help_if_necessary( needs_help ); @@ -466,13 +455,19 @@ RTEMS_INLINE_ROUTINE Priority_Control _Scheduler_Unmap_priority( * * @param[in] scheduler The scheduler instance. * @param[in] the_thread The thread containing the scheduler node. + * @param[in] priority The thread priority. */ RTEMS_INLINE_ROUTINE void _Scheduler_Node_initialize( const Scheduler_Control *scheduler, - Thread_Control *the_thread + Thread_Control *the_thread, + Priority_Control priority ) { - return ( *scheduler->Operations.node_initialize )( scheduler, the_thread ); + ( *scheduler->Operations.node_initialize )( + scheduler, + the_thread, + priority + ); } /** @@ -493,32 +488,6 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Node_destroy( } /** - * @brief Updates the scheduler about a priority change of a not ready thread. - * - * @param[in] the_thread The thread. - * @param[in] new_priority The new priority of the thread. - */ -RTEMS_INLINE_ROUTINE void _Scheduler_Update_priority( - Thread_Control *the_thread, - Priority_Control new_priority -) -{ - const Scheduler_Control *scheduler; - ISR_lock_Context lock_context; - - scheduler = _Scheduler_Get( the_thread ); - _Scheduler_Acquire_critical( scheduler, &lock_context ); - - ( *scheduler->Operations.update_priority )( - scheduler, - the_thread, - new_priority - ); - - _Scheduler_Release_critical( scheduler, &lock_context ); -} - -/** * @brief Releases a job of a thread with respect to the scheduler. * * @param[in] the_thread The thread. @@ -639,8 +608,11 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_Set( _Scheduler_Node_destroy( current_scheduler, the_thread ); the_thread->Scheduler.own_control = scheduler; the_thread->Scheduler.control = scheduler; - _Scheduler_Node_initialize( scheduler, the_thread ); - _Scheduler_Update_priority( the_thread, the_thread->current_priority ); + _Scheduler_Node_initialize( + scheduler, + the_thread, + the_thread->current_priority + ); if ( _States_Is_ready( current_state ) ) { _Scheduler_Unblock( the_thread ); @@ -827,22 +799,73 @@ RTEMS_INLINE_ROUTINE Scheduler_Node *_Scheduler_Thread_get_node( } RTEMS_INLINE_ROUTINE void _Scheduler_Node_do_initialize( - Scheduler_Node *node, - Thread_Control *the_thread + Scheduler_Node *node, + Thread_Control *the_thread, + Priority_Control priority ) { + node->Priority.value = priority; + node->Priority.prepend_it = false; + #if defined(RTEMS_SMP) node->user = the_thread; node->help_state = SCHEDULER_HELP_YOURSELF; node->owner = the_thread; node->idle = NULL; node->accepts_help = the_thread; + _SMP_sequence_lock_Initialize( &node->Priority.Lock ); #else - (void) node; (void) the_thread; #endif } +RTEMS_INLINE_ROUTINE Priority_Control _Scheduler_Node_get_priority( + Scheduler_Node *node, + bool *prepend_it_p +) +{ + Priority_Control priority; + bool prepend_it; + +#if defined(RTEMS_SMP) + unsigned int seq; + + do { + seq = _SMP_sequence_lock_Read_begin( &node->Priority.Lock ); +#endif + + priority = node->Priority.value; + prepend_it = node->Priority.prepend_it; + +#if defined(RTEMS_SMP) + } while ( _SMP_sequence_lock_Read_retry( &node->Priority.Lock, seq ) ); +#endif + + *prepend_it_p = prepend_it; + + return priority; +} + +RTEMS_INLINE_ROUTINE void _Scheduler_Node_set_priority( + Scheduler_Node *node, + Priority_Control new_priority, + bool prepend_it +) +{ +#if defined(RTEMS_SMP) + unsigned int seq; + + seq = _SMP_sequence_lock_Write_begin( &node->Priority.Lock ); +#endif + + node->Priority.value = new_priority; + node->Priority.prepend_it = prepend_it; + +#if defined(RTEMS_SMP) + _SMP_sequence_lock_Write_end( &node->Priority.Lock, seq ); +#endif +} + #if defined(RTEMS_SMP) /** * @brief Gets an idle thread from the scheduler instance. |