URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [exec/] [score/] [src/] [coremutexseize.c] - Rev 227
Go to most recent revision | Compare with Previous | Blame | View Log
/* * Mutex Handler * * DESCRIPTION: * * This package is the implementation of the Mutex Handler. * This handler provides synchronization and mutual exclusion capabilities. * * COPYRIGHT (c) 1989-1999. * On-Line Applications Research Corporation (OAR). * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.OARcorp.com/rtems/license.html. * * $Id: coremutexseize.c,v 1.2 2001-09-27 11:59:34 chris Exp $ */ #include <rtems/system.h> #include <rtems/score/isr.h> #include <rtems/score/coremutex.h> #include <rtems/score/states.h> #include <rtems/score/thread.h> #include <rtems/score/threadq.h> /*PAGE * * _CORE_mutex_Seize * * This routine attempts to allocate a mutex to the calling thread. * * Input parameters: * the_mutex - pointer to mutex control block * id - id of object to wait on * wait - TRUE if wait is allowed, FALSE otherwise * timeout - number of ticks to wait (0 means forever) * * Output parameters: NONE * * INTERRUPT LATENCY: * available * wait */ void _CORE_mutex_Seize( CORE_mutex_Control *the_mutex, Objects_Id id, boolean wait, Watchdog_Interval timeout ) { Thread_Control *executing; ISR_Level level; executing = _Thread_Executing; switch ( the_mutex->Attributes.discipline ) { case CORE_MUTEX_DISCIPLINES_FIFO: case CORE_MUTEX_DISCIPLINES_PRIORITY: case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: break; case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: if ( executing->current_priority < the_mutex->Attributes.priority_ceiling) { executing->Wait.return_code = CORE_MUTEX_STATUS_CEILING_VIOLATED; return; } } executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL; _ISR_Disable( level ); if ( ! _CORE_mutex_Is_locked( the_mutex ) ) { the_mutex->lock = CORE_MUTEX_LOCKED; the_mutex->holder = executing; the_mutex->holder_id = executing->Object.id; the_mutex->nest_count = 1; executing->resource_count++; _ISR_Enable( level ); switch ( the_mutex->Attributes.discipline ) { case CORE_MUTEX_DISCIPLINES_FIFO: case CORE_MUTEX_DISCIPLINES_PRIORITY: case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: /* already the highest priority */ break; case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: if ( the_mutex->Attributes.priority_ceiling < executing->current_priority ) { _Thread_Change_priority( the_mutex->holder, the_mutex->Attributes.priority_ceiling, FALSE ); } } executing->Wait.return_code = CORE_MUTEX_STATUS_SUCCESSFUL; return; } if ( _Thread_Is_executing( the_mutex->holder ) ) { switch ( the_mutex->Attributes.lock_nesting_behavior ) { case CORE_MUTEX_NESTING_ACQUIRES: the_mutex->nest_count++; _ISR_Enable( level ); return; case CORE_MUTEX_NESTING_IS_ERROR: executing->Wait.return_code = CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED; _ISR_Enable( level ); return; case CORE_MUTEX_NESTING_BLOCKS: break; } } if ( !wait ) { _ISR_Enable( level ); executing->Wait.return_code = CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT; return; } _Thread_queue_Enter_critical_section( &the_mutex->Wait_queue ); executing->Wait.queue = &the_mutex->Wait_queue; executing->Wait.id = id; _ISR_Enable( level ); switch ( the_mutex->Attributes.discipline ) { case CORE_MUTEX_DISCIPLINES_FIFO: case CORE_MUTEX_DISCIPLINES_PRIORITY: case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: break; case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: if ( the_mutex->holder->current_priority > executing->current_priority ) { _Thread_Change_priority( the_mutex->holder, executing->current_priority, FALSE ); } break; } _Thread_queue_Enqueue( &the_mutex->Wait_queue, timeout ); if ( _Thread_Executing->Wait.return_code == CORE_MUTEX_STATUS_SUCCESSFUL ) { switch ( the_mutex->Attributes.discipline ) { case CORE_MUTEX_DISCIPLINES_FIFO: case CORE_MUTEX_DISCIPLINES_PRIORITY: case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT: break; case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING: if ( the_mutex->Attributes.priority_ceiling < executing->current_priority ) { _Thread_Change_priority( executing, the_mutex->Attributes.priority_ceiling, FALSE ); }; break; } } }
Go to most recent revision | Compare with Previous | Blame | View Log