diff options
Diffstat (limited to 'cpukit/score/src/threadqenqueuepriority.c')
| -rw-r--r-- | cpukit/score/src/threadqenqueuepriority.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/cpukit/score/src/threadqenqueuepriority.c b/cpukit/score/src/threadqenqueuepriority.c new file mode 100644 index 0000000000..0d30529e0f --- /dev/null +++ b/cpukit/score/src/threadqenqueuepriority.c @@ -0,0 +1,197 @@ +/* + * Thread Queue Handler - Enqueue By Priority + * + * COPYRIGHT (c) 1989-2009. + * 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.com/license/LICENSE. + * + * $Id$ + */ + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +#include <rtems/system.h> +#include <rtems/score/chain.h> +#include <rtems/score/isr.h> +#include <rtems/score/object.h> +#include <rtems/score/states.h> +#include <rtems/score/thread.h> +#include <rtems/score/threadq.h> +#include <rtems/score/tqdata.h> + +/* + * Support the user forcing the unrolling to be disabled. + */ +#if __RTEMS_DO_NOT_UNROLL_THREADQ_ENQUEUE_PRIORITY__ + #undef CPU_UNROLL_ENQUEUE_PRIORITY + #define CPU_UNROLL_ENQUEUE_PRIORITY FALSE +#endif + +/*PAGE + * + * _Thread_queue_Enqueue_priority + * + * This routine places a blocked thread on a priority thread queue. + * + * Input parameters: + * the_thread_queue - pointer to threadq + * thread - thread to insert + * + * Output parameters: NONE + * + * INTERRUPT LATENCY: + * forward less than + * forward equal + */ + +Thread_blocking_operation_States _Thread_queue_Enqueue_priority ( + Thread_queue_Control *the_thread_queue, + Thread_Control *the_thread, + ISR_Level *level_p +) +{ + Priority_Control search_priority; + Thread_Control *search_thread; + ISR_Level level; + Chain_Control *header; + uint32_t header_index; + Chain_Node *the_node; + Chain_Node *next_node; + Chain_Node *previous_node; + Chain_Node *search_node; + Priority_Control priority; + States_Control block_state; + + _Chain_Initialize_empty( &the_thread->Wait.Block2n ); + + priority = the_thread->current_priority; + header_index = _Thread_queue_Header_number( priority ); + header = &the_thread_queue->Queues.Priority[ header_index ]; + block_state = the_thread_queue->state; + + if ( _Thread_queue_Is_reverse_search( priority ) ) + goto restart_reverse_search; + +restart_forward_search: + search_priority = PRIORITY_MINIMUM - 1; + _ISR_Disable( level ); + search_thread = (Thread_Control *) _Chain_First( header ); + while ( !_Chain_Is_tail( header, (Chain_Node *)search_thread ) ) { + search_priority = search_thread->current_priority; + if ( priority <= search_priority ) + break; + +#if ( CPU_UNROLL_ENQUEUE_PRIORITY == TRUE ) + search_thread = (Thread_Control *) search_thread->Object.Node.next; + if ( _Chain_Is_tail( header, (Chain_Node *)search_thread ) ) + break; + search_priority = search_thread->current_priority; + if ( priority <= search_priority ) + break; +#endif + _ISR_Flash( level ); + if ( !_States_Are_set( search_thread->current_state, block_state) ) { + _ISR_Enable( level ); + goto restart_forward_search; + } + search_thread = + (Thread_Control *)search_thread->Object.Node.next; + } + + if ( the_thread_queue->sync_state != + THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED ) + goto synchronize; + + the_thread_queue->sync_state = THREAD_BLOCKING_OPERATION_SYNCHRONIZED; + + if ( priority == search_priority ) + goto equal_priority; + + search_node = (Chain_Node *) search_thread; + previous_node = search_node->previous; + the_node = (Chain_Node *) the_thread; + + the_node->next = search_node; + the_node->previous = previous_node; + previous_node->next = the_node; + search_node->previous = the_node; + the_thread->Wait.queue = the_thread_queue; + _ISR_Enable( level ); + return THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED; + +restart_reverse_search: + search_priority = PRIORITY_MAXIMUM + 1; + + _ISR_Disable( level ); + search_thread = (Thread_Control *) _Chain_Last( header ); + while ( !_Chain_Is_head( header, (Chain_Node *)search_thread ) ) { + search_priority = search_thread->current_priority; + if ( priority >= search_priority ) + break; +#if ( CPU_UNROLL_ENQUEUE_PRIORITY == TRUE ) + search_thread = (Thread_Control *) search_thread->Object.Node.previous; + if ( _Chain_Is_head( header, (Chain_Node *)search_thread ) ) + break; + search_priority = search_thread->current_priority; + if ( priority >= search_priority ) + break; +#endif + _ISR_Flash( level ); + if ( !_States_Are_set( search_thread->current_state, block_state) ) { + _ISR_Enable( level ); + goto restart_reverse_search; + } + search_thread = (Thread_Control *) + search_thread->Object.Node.previous; + } + + if ( the_thread_queue->sync_state != + THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED ) + goto synchronize; + + the_thread_queue->sync_state = THREAD_BLOCKING_OPERATION_SYNCHRONIZED; + + if ( priority == search_priority ) + goto equal_priority; + + search_node = (Chain_Node *) search_thread; + next_node = search_node->next; + the_node = (Chain_Node *) the_thread; + + the_node->next = next_node; + the_node->previous = search_node; + search_node->next = the_node; + next_node->previous = the_node; + the_thread->Wait.queue = the_thread_queue; + _ISR_Enable( level ); + return THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED; + +equal_priority: /* add at end of priority group */ + search_node = _Chain_Tail( &search_thread->Wait.Block2n ); + previous_node = search_node->previous; + the_node = (Chain_Node *) the_thread; + + the_node->next = search_node; + the_node->previous = previous_node; + previous_node->next = the_node; + search_node->previous = the_node; + the_thread->Wait.queue = the_thread_queue; + _ISR_Enable( level ); + return THREAD_BLOCKING_OPERATION_NOTHING_HAPPENED; + +synchronize: + /* + * An interrupt completed the thread's blocking request. + * For example, the blocking thread could have been given + * the mutex by an ISR or timed out. + * + * WARNING! Returning with interrupts disabled! + */ + *level_p = level; + return the_thread_queue->sync_state; +} |