diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2000-01-05 22:19:21 +0000 |
---|---|---|
committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2000-01-05 22:19:21 +0000 |
commit | 5870ac55678115857215a4199f519263599ee341 (patch) | |
tree | 8b6f044ae7cccc3da9a3bd69b2468c2ca77acff8 /cpukit/score/src/coremutexsurrender.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 '')
-rw-r--r-- | cpukit/score/src/coremutexsurrender.c | 39 |
1 files changed, 17 insertions, 22 deletions
diff --git a/cpukit/score/src/coremutexsurrender.c b/cpukit/score/src/coremutexsurrender.c index 447a5421e8..d64badae1f 100644 --- a/cpukit/score/src/coremutexsurrender.c +++ b/cpukit/score/src/coremutexsurrender.c @@ -49,9 +49,9 @@ CORE_mutex_Status _CORE_mutex_Surrender( ) { Thread_Control *the_thread; - Thread_Control *executing; + Thread_Control *holder; - executing = _Thread_Executing; + holder = the_mutex->holder; /* * The following code allows a thread (or ISR) other than the thread @@ -61,20 +61,9 @@ CORE_mutex_Status _CORE_mutex_Surrender( * must be released by the thread which acquired them. */ - if ( the_mutex->Attributes.allow_nesting ) { - if ( !_Objects_Are_ids_equal( - _Thread_Executing->Object.id, the_mutex->holder_id ) ) { - - switch ( the_mutex->Attributes.discipline ) { - case CORE_MUTEX_DISCIPLINES_FIFO: - case CORE_MUTEX_DISCIPLINES_PRIORITY: - break; - case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: - case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: - return( CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE ); - break; - } - } + if ( the_mutex->Attributes.only_owner_release ) { + if ( !_Thread_Is_executing( holder ) ) + return( CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE ); } /* XXX already unlocked -- not right status */ @@ -85,9 +74,15 @@ CORE_mutex_Status _CORE_mutex_Surrender( the_mutex->nest_count--; if ( the_mutex->nest_count != 0 ) { - if ( the_mutex->Attributes.allow_nesting ) - return( CORE_MUTEX_STATUS_SUCCESSFUL ); - return( CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED ); + switch ( the_mutex->Attributes.lock_nesting_behavior ) { + case CORE_MUTEX_NESTING_ACQUIRES: + return CORE_MUTEX_STATUS_SUCCESSFUL; + case CORE_MUTEX_NESTING_IS_ERROR: + /* should never occur */ + return CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED; + case CORE_MUTEX_NESTING_BLOCKS: + break; + } } _Thread_Executing->resource_count--; @@ -106,9 +101,9 @@ CORE_mutex_Status _CORE_mutex_Surrender( break; case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: - if ( executing->resource_count == 0 && - executing->real_priority != executing->current_priority ) { - _Thread_Change_priority( executing, executing->real_priority, TRUE ); + if ( holder->resource_count == 0 && + holder->real_priority != holder->current_priority ) { + _Thread_Change_priority( holder, holder->real_priority, TRUE ); } break; } |