/** * @file rtems/rtems/event.h */ /* * This include file contains the information pertaining to the Event * Manager. This manager provides a high performance method of communication * and synchronization. * * Directives provided are: * * + send an event set to a task * + receive event condition * * * 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.rtems.com/license/LICENSE. * * $Id: event.h,v 1.19 2005/01/28 05:00:20 ralf Exp $ */ #ifndef _RTEMS_RTEMS_EVENT_H #define _RTEMS_RTEMS_EVENT_H #ifdef __cplusplus extern "C" { #endif #include #include #include #include #include #include /* * This constant is passed as the event_in to the * rtems_event_receive directive to determine which events are pending. */ #define EVENT_CURRENT 0 /* * The following enumerated types indicate what happened while the event * manager was in the synchronization window. */ typedef enum { EVENT_SYNC_SYNCHRONIZED, EVENT_SYNC_NOTHING_HAPPENED, EVENT_SYNC_TIMEOUT, EVENT_SYNC_SATISFIED } Event_Sync_states; /* * Event_Manager_initialization * * DESCRIPTION: * * This routine performs the initialization necessary for this manager. */ void _Event_Manager_initialization( void ); /* * rtems_event_send * * DESCRIPTION: * * This routine implements the rtems_event_send directive. It sends * event_in to the task specified by ID. If the task is blocked * waiting to receive events and the posting of event_in satisfies * the task's event condition, then it is unblocked. */ rtems_status_code rtems_event_send ( Objects_Id id, rtems_event_set event_in ); /* * rtems_event_receive * * DESCRIPTION: * * This routine implements the rtems_event_receive directive. This * directive is invoked when the calling task wishes to receive * the event_in event condition. One of the fields in the option_set * parameter determines whether the receive request is satisfied if * any or all of the events are pending. If the event condition * is not satisfied immediately, then the task may block with an * optional timeout of TICKS clock ticks or return immediately. * This determination is based on another field in the option_set * parameter. This directive returns the events received in the * event_out parameter. */ rtems_status_code rtems_event_receive ( rtems_event_set event_in, rtems_option option_set, rtems_interval ticks, rtems_event_set *event_out ); /* * _Event_Seize * * DESCRIPTION: * * This routine determines if the event condition event_in is * satisfied. If so or if the no_wait option is enabled in option_set, * then the procedure returns immediately. If neither of these * conditions is true, then the calling task is blocked with an * optional timeout of ticks clock ticks. */ void _Event_Seize ( rtems_event_set event_in, rtems_option option_set, rtems_interval ticks, rtems_event_set *event_out ); /* * _Event_Surrender * * DESCRIPTION: * * This routine determines if the event condition of the_thread * has been satisfied. If so, it unblocks the_thread. */ void _Event_Surrender ( Thread_Control *the_thread ); /* * _Event_Timeout * * DESCRIPTION: * * This routine is invoked when a task's event receive request * has not been satisfied after the specified timeout interval. * The task represented by ID will be unblocked and its status * code will be set in it's control block to indicate that a timeout * has occurred. */ void _Event_Timeout ( Objects_Id id, void *ignored ); /* * The following defines the synchronization flag used by the * Event Manager to insure that signals sent to the currently * executing thread are received properly. */ RTEMS_EXTERN volatile Event_Sync_states _Event_Sync_state; #if defined(RTEMS_MULTIPROCESSING) #include #endif #ifndef __RTEMS_APPLICATION__ #include #endif #ifdef __cplusplus } #endif #endif /* end of include file */
