📄 tx_efg.c
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/**************************************************************************/
/* */
/* Copyright (c) 1996-2000 by Express Logic Inc. */
/* */
/* This software is copyrighted by and is the sole property of Express */
/* Logic, Inc. All rights, title, ownership, or other interests */
/* in the software remain the property of Express Logic, Inc. This */
/* software may only be used in accordance with the corresponding */
/* license agreement. Any unauthorized use, duplication, transmission, */
/* distribution, or disclosure of this software is expressly forbidden. */
/* */
/* This Copyright notice may not be removed or modified without prior */
/* written consent of Express Logic, Inc. */
/* */
/* Express Logic, Inc. reserves the right to modify this software */
/* without notice. */
/* */
/* Express Logic, Inc. */
/* 11440 West Bernardo Court info@expresslogic.com */
/* Suite 366 http://www.expresslogic.com */
/* San Diego, CA 92127 */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Event Flags (EVE) */
/** */
/**************************************************************************/
/**************************************************************************/
#define TX_SOURCE_CODE
/* Include necessary system files. */
#include "tx_api.h"
#include "tx_thr.h"
#include "tx_tim.h"
#include "tx_eve.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_event_flags_get PORTABLE C */
/* 3.0f */
/* AUTHOR */
/* */
/* William E. Lamie, Express Logic, Inc. */
/* */
/* DESCRIPTION */
/* */
/* This function gets the specified event flags from the group, */
/* acording to the get option. The get option also specifies whether */
/* or not the retrieved flags are cleared. */
/* */
/* INPUT */
/* */
/* group_ptr Pointer to group control block */
/* requested_event_flags Event flags requested */
/* get_option Specifies and/or and clear options*/
/* actual_flags_ptr Pointer to place the actual flags */
/* the service retrieved */
/* wait_option Suspension option */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _tx_timer_activate Activate timer routine */
/* _tx_thread_suspend Suspend thread service */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 12-31-1996 William E. Lamie Initial Version 3.0 */
/* 11-11-1997 William E. Lamie Modified comment(s), */
/* resulting in version 3.0b. */
/* 03-01-1998 William E. Lamie Optimized post RESTORE */
/* processing, resulting in */
/* version 3.0d. */
/* 01-01-1999 William E. Lamie Modified comment(s), */
/* resulting in version 3.0e. */
/* 11-01-1999 William E. Lamie Modified comment(s), */
/* added logic to track events,*/
/* resulting in version 3.0f. */
/* */
/**************************************************************************/
UINT _tx_event_flags_get(TX_EVENT_FLAGS_GROUP *group_ptr, ULONG requested_flags,
UINT get_option, ULONG *actual_flags_ptr, ULONG wait_option)
{
TX_INTERRUPT_SAVE_AREA
REG_1 UINT status; /* Return status */
REG_2 TX_THREAD *thread_ptr; /* Working thread pointer */
/* Disable interrupts to examine the event flags group. */
TX_DISABLE
/* Log this kernel call. */
TX_EL_EVENT_FLAGS_GET_INSERT
/* Determine if the event flags are present, based on the get option. */
if (get_option & TX_EVENT_FLAGS_AND_MASK)
{
/* All flags must be present to satisfy request. */
if ((group_ptr -> tx_event_flags_current & requested_flags) == requested_flags)
/* Yes, all the events are present. */
status = TX_SUCCESS;
else
/* No, not all the events are present. */
status = TX_NO_EVENTS;
}
else
{
/* Any of the events will satisfy the request. */
if (group_ptr -> tx_event_flags_current & requested_flags)
/* Yes, one or more of the requested events are set. */
status = TX_SUCCESS;
else
/* No, none of the events are currently set. */
status = TX_NO_EVENTS;
}
/* Now determine if the request can be satisfied immediately. */
if (status == TX_SUCCESS)
{
/* Yes, this request can be handled immediately. */
/* Return the actual event flags that satisfied the request. */
*actual_flags_ptr = group_ptr -> tx_event_flags_current;
/* Determine whether or not clearing needs to take place. */
if (get_option & TX_EVENT_FLAGS_CLEAR_MASK)
/* Yes, clear the flags that satisfied this request. */
group_ptr -> tx_event_flags_current =
group_ptr -> tx_event_flags_current & ~requested_flags;
}
else
{
/* Determine if the request specifies suspension. */
if (wait_option)
{
/* Prepare for suspension of this thread. */
/* Pickup thread pointer. */
thread_ptr = _tx_thread_current_ptr;
/* Setup cleanup routine pointer. */
thread_ptr -> tx_suspend_cleanup = _tx_event_flags_cleanup;
/* Remember which event flags we are looking for. */
thread_ptr -> tx_suspend_info = requested_flags;
/* Save the get option as well. */
thread_ptr -> tx_suspend_option = get_option;
/* Save the destination for the current events. */
thread_ptr -> tx_additional_suspend_info = (VOID_PTR) actual_flags_ptr;
/* Setup cleanup information, i.e. this event flags group control
block. */
thread_ptr -> tx_suspend_control_block = (VOID_PTR) group_ptr;
/* Setup suspension list. */
if (group_ptr -> tx_event_flags_suspension_list)
{
/* This list is not NULL, add current thread to the end. */
thread_ptr -> tx_suspended_next =
group_ptr -> tx_event_flags_suspension_list;
thread_ptr -> tx_suspended_previous =
(group_ptr -> tx_event_flags_suspension_list) -> tx_suspended_previous;
((group_ptr -> tx_event_flags_suspension_list) -> tx_suspended_previous) -> tx_suspended_next =
thread_ptr;
(group_ptr -> tx_event_flags_suspension_list) -> tx_suspended_previous = thread_ptr;
}
else
{
/* No other threads are suspended. Setup the head pointer and
just setup this threads pointers to itself. */
group_ptr -> tx_event_flags_suspension_list = thread_ptr;
thread_ptr -> tx_suspended_next = thread_ptr;
thread_ptr -> tx_suspended_previous = thread_ptr;
}
/* Increment the suspended thread count. */
group_ptr -> tx_event_flags_suspended_count++;
/* Set the state to suspended. */
thread_ptr -> tx_state = TX_EVENT_FLAG;
/* Set the suspending flag. */
thread_ptr -> tx_suspending = TX_TRUE;
/* Temporarily disable preemption. */
_tx_thread_preempt_disable++;
/* Save the timeout value. */
thread_ptr -> tx_thread_timer.tx_remaining_ticks = wait_option;
/* Restore interrupts. */
TX_RESTORE
/* See if we need to start a timer. */
if (wait_option != TX_WAIT_FOREVER)
{
/* A timeout is required. */
/* Activate the thread timer for the timeout. */
_tx_timer_activate(&(thread_ptr -> tx_thread_timer));
}
/* Call actual thread suspension routine. */
_tx_thread_suspend(thread_ptr);
/* Return the completion status. */
return(thread_ptr -> tx_suspend_status);
}
else
/* Immediate return, return error completion. */
status = TX_NO_EVENTS;
}
/* Restore interrupts. */
TX_RESTORE
/* Return completion status. */
return(status);
}
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