diff options
| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2014-05-21 10:33:43 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2014-05-28 10:50:41 +0200 |
| commit | 8fcafdd553f3a564ecb5ab5093d01b29971418da (patch) | |
| tree | 7807b3a4ae28e62f0218f8e20051b1b7e0143206 /cpukit/rtems/src/semrelease.c | |
| parent | bsps/sparc: Change tabs to spaces. (diff) | |
| download | rtems-8fcafdd553f3a564ecb5ab5093d01b29971418da.tar.bz2 | |
score: Multiprocessor Resource Sharing Protocol
Add basic support for the Multiprocessor Resource Sharing Protocol
(MrsP).
The Multiprocessor Resource Sharing Protocol (MrsP) is defined in A.
Burns and A.J. Wellings, A Schedulability Compatible Multiprocessor
Resource Sharing Protocol - MrsP, Proceedings of the 25th Euromicro
Conference on Real-Time Systems (ECRTS 2013), July 2013. It is a
generalization of the Priority Ceiling Protocol to SMP systems. Each
MrsP semaphore uses a ceiling priority per scheduler instance. These
ceiling priorities can be specified with rtems_semaphore_set_priority().
A task obtaining or owning a MrsP semaphore will execute with the
ceiling priority for its scheduler instance as specified by the MrsP
semaphore object. Tasks waiting to get ownership of a MrsP semaphore
will not relinquish the processor voluntarily. In case the owner of a
MrsP semaphore gets preempted it can ask all tasks waiting for this
semaphore to help out and temporarily borrow the right to execute on one
of their assigned processors.
The help out feature is not implemented with this patch.
Diffstat (limited to 'cpukit/rtems/src/semrelease.c')
| -rw-r--r-- | cpukit/rtems/src/semrelease.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/cpukit/rtems/src/semrelease.c b/cpukit/rtems/src/semrelease.c index ff4e792b92..2c4be04c78 100644 --- a/cpukit/rtems/src/semrelease.c +++ b/cpukit/rtems/src/semrelease.c @@ -73,12 +73,24 @@ rtems_status_code rtems_semaphore_release( Objects_Locations location; CORE_mutex_Status mutex_status; CORE_semaphore_Status semaphore_status; + rtems_attribute attribute_set; the_semaphore = _Semaphore_Get( id, &location ); switch ( location ) { case OBJECTS_LOCAL: - if ( !_Attributes_Is_counting_semaphore(the_semaphore->attribute_set) ) { + attribute_set = the_semaphore->attribute_set; +#if defined(RTEMS_SMP) + if ( _Attributes_Is_multiprocessor_resource_sharing( attribute_set ) ) { + MRSP_Status mrsp_status = _MRSP_Release( + &the_semaphore->Core_control.mrsp, + _Thread_Get_executing() + ); + _Objects_Put( &the_semaphore->Object ); + return _Semaphore_Translate_MRSP_status_code( mrsp_status ); + } else +#endif + if ( !_Attributes_Is_counting_semaphore( attribute_set ) ) { mutex_status = _CORE_mutex_Surrender( &the_semaphore->Core_control.mutex, id, |