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Diffstat (limited to 'cpukit/score/src/schedulerpriorityyield.c')
-rw-r--r-- | cpukit/score/src/schedulerpriorityyield.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/cpukit/score/src/schedulerpriorityyield.c b/cpukit/score/src/schedulerpriorityyield.c new file mode 100644 index 0000000000..1a13a4e318 --- /dev/null +++ b/cpukit/score/src/schedulerpriorityyield.c @@ -0,0 +1,77 @@ +/* + * Scheduler Handler + * + * Copyright (C) 2010 Gedare Bloom. + * + * The license and distribution terms for this file may be + * found in 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/apiext.h> +#include <rtems/score/context.h> +#include <rtems/score/interr.h> +#include <rtems/score/isr.h> +#include <rtems/score/object.h> +#include <rtems/score/priority.h> +#include <rtems/score/scheduler.h> +#include <rtems/score/states.h> +#include <rtems/score/sysstate.h> +#include <rtems/score/thread.h> +#include <rtems/score/threadq.h> +#include <rtems/score/userext.h> +#include <rtems/score/wkspace.h> + +/* + * _Scheduler_priority_Yield + * + * This kernel routine will remove the running THREAD from the ready queue + * and place it immediately at the rear of this chain. Reset timeslice + * and yield the processor functions both use this routine, therefore if + * reset is true and this is the only thread on the queue then the + * timeslice counter is reset. The heir THREAD will be updated if the + * running is also the currently the heir. + * + * Input parameters: + * the_scheduler - pointer to scheduler control + * + * Output parameters: NONE + * + * INTERRUPT LATENCY: + * ready chain + * select heir + */ + +void _Scheduler_priority_Yield( + Scheduler_Control *the_scheduler +) +{ + ISR_Level level; + Thread_Control *executing; + Chain_Control *ready; + + executing = _Thread_Executing; + ready = executing->scheduler.priority->ready_chain; + _ISR_Disable( level ); + if ( !_Chain_Has_only_one_node( ready ) ) { + _Chain_Extract_unprotected( &executing->Object.Node ); + _Chain_Append_unprotected( ready, &executing->Object.Node ); + + _ISR_Flash( level ); + + if ( _Thread_Is_heir( executing ) ) + _Thread_Heir = (Thread_Control *) ready->first; + _Thread_Dispatch_necessary = true; + } + else if ( !_Thread_Is_heir( executing ) ) + _Thread_Dispatch_necessary = true; + + _ISR_Enable( level ); +} |