diff options
Diffstat (limited to 'cpukit/score/src/threadchangepriority.c')
| -rw-r--r-- | cpukit/score/src/threadchangepriority.c | 57 |
1 files changed, 37 insertions, 20 deletions
diff --git a/cpukit/score/src/threadchangepriority.c b/cpukit/score/src/threadchangepriority.c index 89d0d2cd5f..9847f54f80 100644 --- a/cpukit/score/src/threadchangepriority.c +++ b/cpukit/score/src/threadchangepriority.c @@ -2,7 +2,7 @@ * Thread Handler * * - * COPYRIGHT (c) 1989-1999. + * COPYRIGHT (c) 1989-2006. * On-Line Applications Research Corporation (OAR). * * The license and distribution terms for this file may be @@ -55,8 +55,8 @@ void _Thread_Change_priority( boolean prepend_it ) { - ISR_Level level; - /* boolean do_prepend = FALSE; */ + ISR_Level level; + States_Control state; /* * If this is a case where prepending the task to its priority is @@ -66,13 +66,6 @@ void _Thread_Change_priority( * change calls (e.g. rtems_task_set_priority) should always do an * append not a prepend. */ - - /* - * Techically, the prepend should conditional on the thread lowering - * its priority but that does allow cxd2004 of the acvc 2.0.1 to - * pass with rtems 4.0.0. This should change when gnat redoes its - * priority scheme. - */ /* if ( prepend_it && _Thread_Is_executing( the_thread ) && @@ -80,26 +73,46 @@ void _Thread_Change_priority( prepend_it = TRUE; */ + /* + * Set a transient state for the thread so it is pulled off the Ready chains. + * This will prevent it from being scheduled no matter what happens in an + * ISR. + */ _Thread_Set_transient( the_thread ); - if ( the_thread->current_priority != new_priority ) + /* + * Do not bother recomputing all the priority related information if + * we are not REALLY changing priority. + */ + if ( the_thread->current_priority != new_priority ) _Thread_Set_priority( the_thread, new_priority ); _ISR_Disable( level ); - the_thread->current_state = - _States_Clear( STATES_TRANSIENT, the_thread->current_state ); - - if ( ! _States_Is_ready( the_thread->current_state ) ) { - /* - * XXX If a task is to be reordered while blocked on a priority - * XXX priority ordered thread queue, then this is where that - * XXX should occur. - */ + /* + * If the thread has more than STATES_TRANSIENT set, then it is blocked, + * If it is blocked on a thread queue, then we need to requeue it. + */ + state = the_thread->current_state; + if ( state != STATES_TRANSIENT ) { + if ( _States_Is_waiting_on_thread_queue( state ) ) { + _ISR_Enable( level ); + _Thread_queue_Requeue( the_thread->Wait.queue, the_thread ); + _ISR_Disable( level ); /* redisable so state is cleared with ISR off */ + } + the_thread->current_state = _States_Clear( STATES_TRANSIENT, state ); _ISR_Enable( level ); return; } + /* + * Interrupts are STILL disabled. + * We now know the thread will be in the READY state when we remove + * the TRANSIENT state. So we have to place it on the appropriate + * Ready Queue with interrupts off. + */ + the_thread->current_state = _States_Clear( STATES_TRANSIENT, state ); + _Priority_Add_to_bit_map( &the_thread->Priority_map ); if ( prepend_it ) _Chain_Prepend_unprotected( the_thread->ready, &the_thread->Object.Node ); @@ -108,6 +121,10 @@ void _Thread_Change_priority( _ISR_Flash( level ); + /* + * We altered the set of thread priorities. So let's figure out + * who is the heir and if we need to switch to them. + */ _Thread_Calculate_heir(); if ( !_Thread_Is_executing_also_the_heir() && |