diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2000-01-05 22:19:21 +0000 |
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committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2000-01-05 22:19:21 +0000 |
commit | 5870ac55678115857215a4199f519263599ee341 (patch) | |
tree | 8b6f044ae7cccc3da9a3bd69b2468c2ca77acff8 /cpukit/rtems/src/semcreate.c | |
parent | Updated to reflect a time that had previously been left out due to (diff) | |
download | rtems-5870ac55678115857215a4199f519263599ee341.tar.bz2 |
Added support for simple binary semaphores in addition to the high
power binary/mutex style semaphores already supported by RTEMS. This
was done at the request of Eric Norum <eric@cls.usask.ca> in support
of his effort to port EPICS to RTEMS. This change consisted of
changing the nesting_allowed boolean into a lock_nesting_behavior
enumerated value as well as allowing the core mutex object to optionally
support ensuring that the holder of a binary semaphore released it.
Finally, a more subtle enhancement was to allow the non-holder to release
a priority inheritance/ceiling mutex and still allow the holding task
to return to its original priority.
Diffstat (limited to 'cpukit/rtems/src/semcreate.c')
-rw-r--r-- | cpukit/rtems/src/semcreate.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/cpukit/rtems/src/semcreate.c b/cpukit/rtems/src/semcreate.c index a63814acfe..3ffbfc39c0 100644 --- a/cpukit/rtems/src/semcreate.c +++ b/cpukit/rtems/src/semcreate.c @@ -96,13 +96,15 @@ rtems_status_code rtems_semaphore_create( if ( _Attributes_Is_inherit_priority( attribute_set ) || _Attributes_Is_priority_ceiling( attribute_set ) ) { - if ( ! ( _Attributes_Is_binary_semaphore( attribute_set ) && + if ( ! ( (_Attributes_Is_binary_semaphore( attribute_set ) || + _Attributes_Is_simple_binary_semaphore( attribute_set )) && + _Attributes_Is_priority( attribute_set ) ) ) return RTEMS_NOT_DEFINED; } - if ( _Attributes_Is_binary_semaphore( attribute_set ) && ( count > 1 ) ) + if ( !_Attributes_Is_counting_semaphore( attribute_set ) && ( count > 1 ) ) return RTEMS_INVALID_NUMBER; _Thread_Disable_dispatch(); /* prevents deletion */ @@ -126,7 +128,13 @@ rtems_status_code rtems_semaphore_create( the_semaphore->attribute_set = attribute_set; - if ( _Attributes_Is_binary_semaphore( attribute_set ) ) { + /* + * If it is not a counting, semaphore, then it is either a + * simple binary semaphore or a more powerful lmutex style binary + * semaphore. + */ + + if ( !_Attributes_Is_counting_semaphore( attribute_set ) ) { if ( _Attributes_Is_inherit_priority( attribute_set ) ) the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT; else if ( _Attributes_Is_priority_ceiling( attribute_set ) ) @@ -136,12 +144,24 @@ rtems_status_code rtems_semaphore_create( else the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_FIFO; - if ( _Attributes_Is_nesting_allowed( attribute_set ) ) - the_mutex_attributes.allow_nesting = TRUE; - else - the_mutex_attributes.allow_nesting = FALSE; - /* Add priority ceiling code here ????? */ + if ( _Attributes_Is_binary_semaphore( attribute_set ) ) { + the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES; + + switch ( the_mutex_attributes.discipline ) { + case CORE_MUTEX_DISCIPLINES_FIFO: + case CORE_MUTEX_DISCIPLINES_PRIORITY: + the_mutex_attributes.only_owner_release = FALSE; + break; + case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: + case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: + the_mutex_attributes.only_owner_release = TRUE; + break; + } + } else { + the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS; + the_mutex_attributes.only_owner_release = FALSE; + } the_mutex_attributes.priority_ceiling = priority_ceiling; @@ -161,8 +181,7 @@ rtems_status_code rtems_semaphore_create( NULL #endif ); - } - else { + } else { if ( _Attributes_Is_priority( attribute_set ) ) the_semaphore_attributes.discipline = CORE_SEMAPHORE_DISCIPLINES_PRIORITY; else @@ -178,7 +197,7 @@ rtems_status_code rtems_semaphore_create( * The following are just to make Purify happy. */ - the_mutex_attributes.allow_nesting = TRUE; + the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES; the_mutex_attributes.priority_ceiling = PRIORITY_MINIMUM; _CORE_semaphore_Initialize( |