diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-11-02 21:48:15 +0000 |
---|---|---|
committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 1999-11-02 21:48:15 +0000 |
commit | 7cc8d6c3b1a207684892d207055ceff9f37d5731 (patch) | |
tree | 3da2f9ee0425a6b49a32df5c8298789de0672add /cpukit/score/src/coremutexseize.c | |
parent | Split core message queue and watchdog handler objects into separate files. (diff) | |
download | rtems-7cc8d6c3b1a207684892d207055ceff9f37d5731.tar.bz2 |
Split core mutex and semaphore handlers into separate files.
Diffstat (limited to 'cpukit/score/src/coremutexseize.c')
-rw-r--r-- | cpukit/score/src/coremutexseize.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/cpukit/score/src/coremutexseize.c b/cpukit/score/src/coremutexseize.c new file mode 100644 index 0000000000..a2c8a37d71 --- /dev/null +++ b/cpukit/score/src/coremutexseize.c @@ -0,0 +1,156 @@ +/* + * Mutex Handler + * + * DESCRIPTION: + * + * This package is the implementation of the Mutex Handler. + * This handler provides synchronization and mutual exclusion capabilities. + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * 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. + * + * $Id$ + */ + +#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 + ); + } + } + return; + } + + if ( _Objects_Are_ids_equal( + _Thread_Executing->Object.id, the_mutex->holder_id ) ) { + if ( _CORE_mutex_Is_nesting_allowed( &the_mutex->Attributes ) ) + the_mutex->nest_count++; + else + executing->Wait.return_code = CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED; + + _ISR_Enable( level ); + return; + } + + 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; + } + } +} + |