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Diffstat (limited to 'cpukit/score/include/rtems/score/coresemimpl.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/coresemimpl.h | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/cpukit/score/include/rtems/score/coresemimpl.h b/cpukit/score/include/rtems/score/coresemimpl.h new file mode 100644 index 0000000000..241ca41461 --- /dev/null +++ b/cpukit/score/include/rtems/score/coresemimpl.h @@ -0,0 +1,255 @@ +/** + * @file + * + * @brief Inlined Routines Associated with the SuperCore Semaphore + * + * This include file contains all of the inlined routines associated + * with the SuperCore semaphore. + */ + +/* + * COPYRIGHT (c) 1989-2006. + * 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.rtems.com/license/LICENSE. + */ + +#ifndef _RTEMS_SCORE_CORESEMIMPL_H +#define _RTEMS_SCORE_CORESEMIMPL_H + +#include <rtems/score/coresem.h> +#include <rtems/score/thread.h> +#include <rtems/score/threaddispatch.h> +#include <rtems/score/threadq.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @addtogroup ScoreSemaphore + */ +/**@{**/ + +#if defined(RTEMS_POSIX_API) || defined(RTEMS_MULTIPROCESSING) + #define RTEMS_SCORE_CORESEM_ENABLE_SEIZE_BODY +#endif + +/** + * Core Semaphore handler return statuses. + */ +typedef enum { + /** This status indicates that the operation completed successfully. */ + CORE_SEMAPHORE_STATUS_SUCCESSFUL, + /** This status indicates that the calling task did not want to block + * and the operation was unable to complete immediately because the + * resource was unavailable. + */ + CORE_SEMAPHORE_STATUS_UNSATISFIED_NOWAIT, + /** This status indicates that the thread was blocked waiting for an + * operation to complete and the semaphore was deleted. + */ + CORE_SEMAPHORE_WAS_DELETED, + /** This status indicates that the calling task was willing to block + * but the operation was unable to complete within the time allotted + * because the resource never became available. + */ + CORE_SEMAPHORE_TIMEOUT, + /** This status indicates that an attempt was made to unlock the semaphore + * and this would have made its count greater than that allowed. + */ + CORE_SEMAPHORE_MAXIMUM_COUNT_EXCEEDED +} CORE_semaphore_Status; + +/** + * @brief Core semaphore last status value. + * + * This is the last status value. + */ +#define CORE_SEMAPHORE_STATUS_LAST CORE_SEMAPHORE_MAXIMUM_COUNT_EXCEEDED + +/** + * The following type defines the callout which the API provides + * to support global/multiprocessor operations on semaphores. + */ +typedef void ( *CORE_semaphore_API_mp_support_callout )( + Thread_Control *, + Objects_Id + ); + +/** + * @brief Initialize the semaphore based on the parameters passed. + * + * DESCRIPTION: + * + * This package is the implementation of the CORE Semaphore Handler. + * This core object utilizes standard Dijkstra counting semaphores to provide + * synchronization and mutual exclusion capabilities. + * + * This routine initializes the semaphore based on the parameters passed. + * + * @param[in] the_semaphore is the semaphore to initialize + * @param[in] the_semaphore_attributes define the behavior of this instance + * @param[in] initial_value is the initial count of the semaphore + */ +void _CORE_semaphore_Initialize( + CORE_semaphore_Control *the_semaphore, + CORE_semaphore_Attributes *the_semaphore_attributes, + uint32_t initial_value +); + +#if defined(RTEMS_SCORE_CORESEM_ENABLE_SEIZE_BODY) + /** + * This routine attempts to receive a unit from @a the_semaphore. + * If a unit is available or if the wait flag is false, then the routine + * returns. Otherwise, the calling task is blocked until a unit becomes + * available. + * + * @param[in] the_semaphore is the semaphore to seize + * @param[in] id is the Id of the API level Semaphore object associated + * with this instance of a SuperCore Semaphore + * @param[in] wait indicates if the caller is willing to block + * @param[in] timeout is the number of ticks the calling thread is willing + * to wait if @a wait is true. + */ + void _CORE_semaphore_Seize( + CORE_semaphore_Control *the_semaphore, + Objects_Id id, + bool wait, + Watchdog_Interval timeout + ); +#endif + +/** + * @brief Surrender a unit to a semaphore. + * + * This routine frees a unit to the semaphore. If a task was blocked waiting + * for a unit from this semaphore, then that task will be readied and the unit + * given to that task. Otherwise, the unit will be returned to the semaphore. + * + * @param[in] the_semaphore is the semaphore to surrender + * @param[in] id is the Id of the API level Semaphore object associated + * with this instance of a SuperCore Semaphore + * @param[in] api_semaphore_mp_support is the routine to invoke if the + * thread unblocked is remote + * + * @retval an indication of whether the routine succeeded or failed + */ +CORE_semaphore_Status _CORE_semaphore_Surrender( + CORE_semaphore_Control *the_semaphore, + Objects_Id id, + CORE_semaphore_API_mp_support_callout api_semaphore_mp_support +); + +/** + * @brief Core semaphore flush. + * + * DESCRIPTION: + * This package is the implementation of the CORE Semaphore Handler. + * This core object utilizes standard Dijkstra counting semaphores to provide + * synchronization and mutual exclusion capabilities. + * + * This routine assists in the deletion of a semaphore by flushing the + * associated wait queue. + * + * @param[in] the_semaphore is the semaphore to flush + * @param[in] remote_extract_callout is the routine to invoke if the + * thread unblocked is remote + * @param[in] status is the status to be returned to the unblocked thread + */ +void _CORE_semaphore_Flush( + CORE_semaphore_Control *the_semaphore, + Thread_queue_Flush_callout remote_extract_callout, + uint32_t status +); + +/** + * This function returns true if the priority attribute is + * enabled in the @a attribute_set and false otherwise. + * + * @param[in] the_attribute is the attribute set to test + * + * @return true if the priority attribute is enabled + */ +RTEMS_INLINE_ROUTINE bool _CORE_semaphore_Is_priority( + CORE_semaphore_Attributes *the_attribute +) +{ + return ( the_attribute->discipline == CORE_SEMAPHORE_DISCIPLINES_PRIORITY ); +} + +/** + * This routine returns the current count associated with the semaphore. + * + * @param[in] the_semaphore is the semaphore to obtain the count of + * + * @return the current count of this semaphore + */ +RTEMS_INLINE_ROUTINE uint32_t _CORE_semaphore_Get_count( + CORE_semaphore_Control *the_semaphore +) +{ + return the_semaphore->count; +} + +/** + * This routine attempts to receive a unit from the_semaphore. + * If a unit is available or if the wait flag is false, then the routine + * returns. Otherwise, the calling task is blocked until a unit becomes + * available. + * + * @param[in] the_semaphore is the semaphore to obtain + * @param[in] id is the Id of the owning API level Semaphore object + * @param[in] wait is true if the thread is willing to wait + * @param[in] timeout is the maximum number of ticks to block + * @param[in] level is a temporary variable used to contain the ISR + * disable level cookie + * + * @note There is currently no MACRO version of this routine. + */ +RTEMS_INLINE_ROUTINE void _CORE_semaphore_Seize_isr_disable( + CORE_semaphore_Control *the_semaphore, + Objects_Id id, + bool wait, + Watchdog_Interval timeout, + ISR_Level level +) +{ + Thread_Control *executing; + + /* disabled when you get here */ + + executing = _Thread_Executing; + executing->Wait.return_code = CORE_SEMAPHORE_STATUS_SUCCESSFUL; + if ( the_semaphore->count != 0 ) { + the_semaphore->count -= 1; + _ISR_Enable( level ); + return; + } + + if ( !wait ) { + _ISR_Enable( level ); + executing->Wait.return_code = CORE_SEMAPHORE_STATUS_UNSATISFIED_NOWAIT; + return; + } + + _Thread_Disable_dispatch(); + _Thread_queue_Enter_critical_section( &the_semaphore->Wait_queue ); + executing->Wait.queue = &the_semaphore->Wait_queue; + executing->Wait.id = id; + _ISR_Enable( level ); + + _Thread_queue_Enqueue( &the_semaphore->Wait_queue, timeout ); + _Thread_Enable_dispatch(); +} + +/** @} */ + +#ifdef __cplusplus +} +#endif + +#endif +/* end of include file */ |