From 0b713f8940d90b480f8cd36663c11aa0688587d8 Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 30 May 2016 06:59:55 +0200 Subject: score: Rework CORE inherit priority mutex Provide dedicated seize and surrender methods for inherit priority mutexes. This eliminates CORE_mutex_Attributes. --- cpukit/score/src/coremutexsurrender.c | 127 ++++++---------------------------- 1 file changed, 22 insertions(+), 105 deletions(-) (limited to 'cpukit/score/src/coremutexsurrender.c') diff --git a/cpukit/score/src/coremutexsurrender.c b/cpukit/score/src/coremutexsurrender.c index 5075e204c9..6604be89da 100644 --- a/cpukit/score/src/coremutexsurrender.c +++ b/cpukit/score/src/coremutexsurrender.c @@ -18,141 +18,58 @@ #include "config.h" #endif -#include -#include #include -#include -Status_Control _CORE_mutex_Surrender( +Status_Control _CORE_mutex_Surrender_slow( CORE_mutex_Control *the_mutex, + Thread_Control *executing, + Thread_queue_Heads *heads, + bool keep_priority, Thread_queue_Context *queue_context ) { - Thread_Control *the_thread; - Thread_Control *holder; + if ( heads != NULL ) { + const Thread_queue_Operations *operations; + Thread_Control *new_owner; + bool unblock; - holder = the_mutex->holder; + operations = CORE_MUTEX_TQ_OPERATIONS; + new_owner = ( *operations->first )( heads ); - /* - * Priority Ceiling or Priority Inheritance mutexes must be released by the - * thread which acquired them. - */ - if ( !_Thread_Is_executing( holder ) ) { - _ISR_lock_ISR_enable( &queue_context->Lock_context ); - return STATUS_NOT_OWNER; - } - - _CORE_mutex_Acquire_critical( the_mutex, queue_context ); - - /* XXX already unlocked -- not right status */ - - if ( !the_mutex->nest_count ) { - _CORE_mutex_Release( the_mutex, queue_context ); - return STATUS_SUCCESSFUL; - } - - the_mutex->nest_count--; + _CORE_mutex_Set_owner( the_mutex, new_owner ); - if ( the_mutex->nest_count != 0 ) { - /* - * All error checking is on the locking side, so if the lock was - * allowed to acquired multiple times, then we should just deal with - * that. The RTEMS_DEBUG is just a validation. - */ - #if defined(RTEMS_DEBUG) - switch ( the_mutex->Attributes.lock_nesting_behavior ) { - case CORE_MUTEX_NESTING_ACQUIRES: - _CORE_mutex_Release( the_mutex, queue_context ); - return STATUS_SUCCESSFUL; - #if defined(RTEMS_POSIX_API) - case CORE_MUTEX_NESTING_IS_ERROR: - /* should never occur */ - _CORE_mutex_Release( the_mutex, queue_context ); - return STATUS_NESTING_NOT_ALLOWED; - #endif - } - #else - _CORE_mutex_Release( the_mutex, queue_context ); - /* must be CORE_MUTEX_NESTING_ACQUIRES or we wouldn't be here */ - return STATUS_SUCCESSFUL; - #endif - } - - /* - * Formally release the mutex before possibly transferring it to a - * blocked thread. - */ - holder->resource_count--; - the_mutex->holder = NULL; - - /* - * Now we check if another thread was waiting for this mutex. If so, - * transfer the mutex to that thread. - */ - if ( - ( the_thread = _Thread_queue_First_locked( - &the_mutex->Wait_queue, - CORE_MUTEX_TQ_OPERATIONS - ) - ) - ) { - bool unblock; - - the_mutex->holder = the_thread; - the_mutex->nest_count = 1; - - /* - * We must extract the thread now since this will restore its default - * thread lock. This is necessary to avoid a deadlock in the - * _Thread_Change_priority() below due to a recursive thread queue lock - * acquire. - */ unblock = _Thread_queue_Extract_locked( &the_mutex->Wait_queue.Queue, - CORE_MUTEX_TQ_OPERATIONS, - the_thread, + operations, + new_owner, queue_context ); #if defined(RTEMS_MULTIPROCESSING) - if ( _Objects_Is_local_id( the_thread->Object.id ) ) + if ( _Objects_Is_local_id( new_owner->Object.id ) ) #endif { - the_thread->resource_count++; - _Thread_queue_Boost_priority( &the_mutex->Wait_queue.Queue, the_thread ); + ++new_owner->resource_count; + _Thread_queue_Boost_priority( &the_mutex->Wait_queue.Queue, new_owner ); } _Thread_queue_Unblock_critical( unblock, &the_mutex->Wait_queue.Queue, - the_thread, + new_owner, &queue_context->Lock_context ); } else { _CORE_mutex_Release( the_mutex, queue_context ); } - /* - * Whether or not someone is waiting for the mutex, an - * inherited priority must be lowered if this is the last - * mutex (i.e. resource) this task has. - */ - if ( !_Thread_Owns_resources( holder ) ) { - /* - * Ensure that the holder resource count is visible to all other processors - * and that we read the latest priority restore hint. - */ - _Atomic_Fence( ATOMIC_ORDER_ACQ_REL ); - - if ( holder->priority_restore_hint ) { - Per_CPU_Control *cpu_self; + if ( !keep_priority ) { + Per_CPU_Control *cpu_self; - cpu_self = _Thread_Dispatch_disable(); - _Thread_Restore_priority( holder ); - _Thread_Dispatch_enable( cpu_self ); - } + cpu_self = _Thread_Dispatch_disable(); + _Thread_Restore_priority( executing ); + _Thread_Dispatch_enable( cpu_self ); } - _CORE_mutex_Restore_priority( holder ); return STATUS_SUCCESSFUL; } -- cgit v1.2.3