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Diffstat (limited to 'cpukit/rtems/src/semobtain.c')
-rw-r--r-- | cpukit/rtems/src/semobtain.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/cpukit/rtems/src/semobtain.c b/cpukit/rtems/src/semobtain.c new file mode 100644 index 0000000000..c73d84a6da --- /dev/null +++ b/cpukit/rtems/src/semobtain.c @@ -0,0 +1,120 @@ +/* + * Semaphore Manager + * + * DESCRIPTION: + * + * This package is the implementation of the Semaphore Manager. + * This manager utilizes standard Dijkstra counting semaphores to provide + * synchronization and mutual exclusion capabilities. + * + * Directives provided are: + * + * + create a semaphore + * + get an ID of a semaphore + * + delete a semaphore + * + acquire a semaphore + * + release a semaphore + * + * 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/rtems/status.h> +#include <rtems/rtems/support.h> +#include <rtems/rtems/attr.h> +#include <rtems/score/isr.h> +#include <rtems/score/object.h> +#include <rtems/rtems/options.h> +#include <rtems/rtems/sem.h> +#include <rtems/score/coremutex.h> +#include <rtems/score/coresem.h> +#include <rtems/score/states.h> +#include <rtems/score/thread.h> +#include <rtems/score/threadq.h> +#if defined(RTEMS_MULTIPROCESSING) +#include <rtems/score/mpci.h> +#endif +#include <rtems/score/sysstate.h> + +#include <rtems/score/interr.h> + +/*PAGE + * + * rtems_semaphore_obtain + * + * This directive allows a thread to acquire a semaphore. + * + * Input parameters: + * id - semaphore id + * option_set - wait option + * timeout - number of ticks to wait (0 means wait forever) + * + * Output parameters: + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_obtain( + Objects_Id id, + unsigned32 option_set, + rtems_interval timeout +) +{ + register Semaphore_Control *the_semaphore; + Objects_Locations location; + boolean wait; + + the_semaphore = _Semaphore_Get( id, &location ); + switch ( location ) { + case OBJECTS_REMOTE: +#if defined(RTEMS_MULTIPROCESSING) + return _Semaphore_MP_Send_request_packet( + SEMAPHORE_MP_OBTAIN_REQUEST, + id, + option_set, + timeout + ); +#endif + + case OBJECTS_ERROR: + return RTEMS_INVALID_ID; + + case OBJECTS_LOCAL: + if ( _Options_Is_no_wait( option_set ) ) + wait = FALSE; + else + wait = TRUE; + + if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) { + _CORE_mutex_Seize( + &the_semaphore->Core_control.mutex, + id, + wait, + timeout + ); + _Thread_Enable_dispatch(); + return _Semaphore_Translate_core_mutex_return_code( + _Thread_Executing->Wait.return_code ); + } else { + _CORE_semaphore_Seize( + &the_semaphore->Core_control.semaphore, + id, + wait, + timeout + ); + _Thread_Enable_dispatch(); + return _Semaphore_Translate_core_semaphore_return_code( + _Thread_Executing->Wait.return_code ); + } + } + + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} |