/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* EVENT FLAG MANAGEMENT
*
* (c) Copyright 2001, Jean J. Labrosse, Weston, FL
* All Rights Reserved
*
* File : OS_FLAG.C
* By : Jean J. Labrosse
*********************************************************************************************************
*/
#ifndef OS_MASTER_FILE
#include "includes.h"
#endif
#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
/*
*********************************************************************************************************
* LOCAL PROTOTYPES
*********************************************************************************************************
*/
static void OS_FlagBlock(OS_FLAG_GRP *pgrp, OS_FLAG_NODE *pnode, OS_FLAGS flags, INT8U wait_type, INT16U timeout);
static BOOLEAN OS_FlagTaskRdy(OS_FLAG_NODE *pnode, OS_FLAGS flags_rdy);
/*$PAGE*/
/*
*********************************************************************************************************
* CHECK THE STATUS OF FLAGS IN AN EVENT FLAG GROUP
*
* Description: This function is called to check the status of a combination of bits to be set or cleared
* in an event flag group. Your application can check for ANY bit to be set/cleared or ALL
* bits to be set/cleared.
*
* This call does not block if the desired flags are not present.
*
* Arguments : pgrp is a pointer to the desired event flag group.
*
* flags Is a bit pattern indicating which bit(s) (i.e. flags) you wish to check.
* The bits you want are specified by setting the corresponding bits in
* 'flags'. e.g. if your application wants to wait for bits 0 and 1 then
* 'flags' would contain 0x03.
*
* wait_type specifies whether you want ALL bits to be set/cleared or ANY of the bits
* to be set/cleared.
* You can specify the following argument:
*
* OS_FLAG_WAIT_CLR_ALL You will check ALL bits in 'flags' to be clear (0)
* OS_FLAG_WAIT_CLR_ANY You will check ANY bit in 'flags' to be clear (0)
* OS_FLAG_WAIT_SET_ALL You will check ALL bits in 'flags' to be set (1)
* OS_FLAG_WAIT_SET_ANY You will check ANY bit in 'flags' to be set (1)
*
* NOTE: Add OS_FLAG_CONSUME if you want the event flag to be 'consumed' by
* the call. Example, to wait for any flag in a group AND then clear
* the flags that are present, set 'wait_type' to:
*
* OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME
*
* err is a pointer to an error code and can be:
* OS_NO_ERR No error
* OS_ERR_EVENT_TYPE You are not pointing to an event flag group
* OS_FLAG_ERR_WAIT_TYPE You didn't specify a proper 'wait_type' argument.
* OS_FLAG_INVALID_PGRP You passed a NULL pointer instead of the event flag
* group handle.
* OS_FLAG_ERR_NOT_RDY The desired flags you are waiting for are not
* available.
*
* Returns : The state of the flags in the event flag group.
*
* Called from: Task or ISR
*********************************************************************************************************
*/
#if OS_FLAG_ACCEPT_EN > 0
OS_FLAGS OSFlagAccept (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U wait_type, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_FLAGS flags_cur;
OS_FLAGS flags_rdy;
BOOLEAN consume;
#if OS_ARG_CHK_EN > 0
if (pgrp == (OS_FLAG_GRP *)0) { /* Validate 'pgrp' */
*err = OS_FLAG_INVALID_PGRP;
return ((OS_FLAGS)0);
}
if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((OS_FLAGS)0);
}
#endif
if (wait_type & OS_FLAG_CONSUME) { /* See if we need to consume the flags */
wait_type &= ~OS_FLAG_CONSUME;
consume = TRUE;
} else {
consume = FALSE;
}
/*$PAGE*/
*err = OS_NO_ERR; /* Assume NO error until proven otherwise. */
OS_ENTER_CRITICAL();
switch (wait_type) {
case OS_FLAG_WAIT_SET_ALL: /* See if all required flags are set */
flags_rdy = pgrp->OSFlagFlags & flags; /* Extract only the bits we want */
if (flags_rdy == flags) { /* Must match ALL the bits that we want */
if (consume == TRUE) { /* See if we need to consume the flags */
pgrp->OSFlagFlags &= ~flags_rdy; /* Clear ONLY the flags that we wanted */
}
} else {
*err = OS_FLAG_ERR_NOT_RDY;
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
OS_EXIT_CRITICAL();
break;
case OS_FLAG_WAIT_SET_ANY:
flags_rdy = pgrp->OSFlagFlags & flags; /* Extract only the bits we want */
if (flags_rdy != (OS_FLAGS)0) { /* See if any flag set */
if (consume == TRUE) { /* See if we need to consume the flags */
pgrp->OSFlagFlags &= ~flags_rdy; /* Clear ONLY the flags that we got */
}
} else {
*err = OS_FLAG_ERR_NOT_RDY;
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
OS_EXIT_CRITICAL();
break;
#if OS_FLAG_WAIT_CLR_EN > 0
case OS_FLAG_WAIT_CLR_ALL: /* See if all required flags are cleared */
flags_rdy = ~pgrp->OSFlagFlags & flags; /* Extract only the bits we want */
if (flags_rdy == flags) { /* Must match ALL the bits that we want */
if (consume == TRUE) { /* See if we need to consume the flags */
pgrp->OSFlagFlags |= flags_rdy; /* Set ONLY the flags that we wanted */
}
} else {
*err = OS_FLAG_ERR_NOT_RDY;
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
OS_EXIT_CRITICAL();
break;
case OS_FLAG_WAIT_CLR_ANY:
flags_rdy = ~pgrp->OSFlagFlags & flags; /* Extract only the bits we want */
if (flags_rdy != (OS_FLAGS)0) { /* See if any flag cleared */
if (consume == TRUE) { /* See if we need to consume the flags */