From 91e7b0c5ae837c055fd67d77d8db26bfb648261b Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Thu, 27 Mar 2014 09:04:47 +0100 Subject: score: PR2172: _Thread_queue_Extract() Add _Thread_queue_Extract_with_return_code(). On SMP this sequence in _Thread_queue_Process_timeout() was broken: [...] /* * After we enable interrupts here, a lot may happen in the * meantime, e.g. nested interrupts may release the resource that * times out here. So we enter _Thread_queue_Extract() * speculatively. Inside this function we check the actual status * under ISR disable protection. This ensures that exactly one * executing context performs the extract operation (other parties * may call _Thread_queue_Dequeue()). If this context won, then * we have a timeout. * * We can use the_thread_queue pointer here even if * the_thread->Wait.queue is already set to NULL since the extract * operation will only use the thread queue discipline to select * the right extract operation. The timeout status is set during * thread queue initialization. */ we_did_it = _Thread_queue_Extract( the_thread_queue, the_thread ); if ( we_did_it ) { the_thread->Wait.return_code = the_thread_queue->timeout_status; } [...] In case _Thread_queue_Extract() successfully extracted a thread, then this thread may start execution on a remote processor immediately and read the the_thread->Wait.return_code before we update it here with the timeout status. Thus it observes a successful operation even if it timed out. --- cpukit/score/include/rtems/score/threadqimpl.h | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'cpukit/score/include/rtems/score/threadqimpl.h') diff --git a/cpukit/score/include/rtems/score/threadqimpl.h b/cpukit/score/include/rtems/score/threadqimpl.h index 040e16bc07..9d248121ac 100644 --- a/cpukit/score/include/rtems/score/threadqimpl.h +++ b/cpukit/score/include/rtems/score/threadqimpl.h @@ -135,15 +135,18 @@ void _Thread_queue_Requeue( * * @param[in] the_thread_queue is the pointer to the ThreadQ header * @param[in] the_thread is the pointer to a thread control block that is to be removed - * - * @retval true The extract operation was performed by the executing context. - * @retval false Otherwise. */ -bool _Thread_queue_Extract( +void _Thread_queue_Extract( Thread_queue_Control *the_thread_queue, Thread_Control *the_thread ); +void _Thread_queue_Extract_with_return_code( + Thread_queue_Control *the_thread_queue, + Thread_Control *the_thread, + uint32_t return_code +); + /** * @brief Extracts the_thread from the_thread_queue. * @@ -265,8 +268,9 @@ Thread_blocking_operation_States _Thread_queue_Enqueue_priority ( * @retval true The extract operation was performed by the executing context. * @retval false Otherwise. */ -bool _Thread_queue_Extract_priority_helper( +void _Thread_queue_Extract_priority_helper( Thread_Control *the_thread, + uint32_t return_code, bool requeuing ); @@ -276,8 +280,8 @@ bool _Thread_queue_Extract_priority_helper( * This macro wraps the underlying call and hides the requeuing argument. */ -#define _Thread_queue_Extract_priority( _the_thread ) \ - _Thread_queue_Extract_priority_helper( _the_thread, false ) +#define _Thread_queue_Extract_priority( _the_thread, _return_code ) \ + _Thread_queue_Extract_priority_helper( _the_thread, _return_code, false ) /** * @brief Get highest priority thread on the_thread_queue. * @@ -337,8 +341,9 @@ Thread_blocking_operation_States _Thread_queue_Enqueue_fifo ( * This routine removes the_thread from the_thread_queue * and cancels any timeouts associated with this blocking. */ -bool _Thread_queue_Extract_fifo( - Thread_Control *the_thread +void _Thread_queue_Extract_fifo( + Thread_Control *the_thread, + uint32_t return_code ); /** -- cgit v1.2.3