📄 os_flag.c
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* opt == OS_DEL_NO_PEND Deletes the event flag group ONLY if no task pending
* opt == OS_DEL_ALWAYS Deletes the event flag group even if tasks are
* waiting. In this case, all the tasks pending will be
* readied.
*
* err is a pointer to an error code that can contain one of the following values:
* OS_NO_ERR The call was successful and the event flag group was
* deleted
* OS_ERR_DEL_ISR If you attempted to delete the event flag group from
* an ISR
* OS_FLAG_INVALID_PGRP If 'pgrp' is a NULL pointer.
* OS_ERR_EVENT_TYPE You are not pointing to an event flag group
* OS_ERR_EVENT_TYPE If you didn't pass a pointer to an event flag group
* OS_ERR_INVALID_OPT An invalid option was specified
* OS_ERR_TASK_WAITING One or more tasks were waiting on the event flag
* group.
*
* Returns : pevent upon error
* (OS_EVENT *)0 if the semaphore was successfully deleted.
*
* Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
* the event flag group MUST check the return code of OSFlagAccept() and OSFlagPend().
* 2) This call can potentially disable interrupts for a long time. The interrupt disable
* time is directly proportional to the number of tasks waiting on the event flag group.
*********************************************************************************************************
*/
#if OS_FLAG_DEL_EN > 0
OS_FLAG_GRP *OSFlagDel (OS_FLAG_GRP *pgrp, INT8U opt, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
BOOLEAN tasks_waiting;
OS_FLAG_NODE *pnode;
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
return (pgrp);
}
#if OS_ARG_CHK_EN > 0
if (pgrp == (OS_FLAG_GRP *)0) { /* Validate 'pgrp' */
*err = OS_FLAG_INVALID_PGRP;
return (pgrp);
}
if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) { /* Validate event group type */
*err = OS_ERR_EVENT_TYPE;
return (pgrp);
}
#endif
OS_ENTER_CRITICAL();
if (pgrp->OSFlagWaitList != (void *)0) { /* See if any tasks waiting on event flags */
tasks_waiting = TRUE; /* Yes */
} else {
tasks_waiting = FALSE; /* No */
}
switch (opt) {
case OS_DEL_NO_PEND: /* Delete group if no task waiting */
if (tasks_waiting == FALSE) {
pgrp->OSFlagType = OS_EVENT_TYPE_UNUSED;
pgrp->OSFlagWaitList = (void *)OSFlagFreeList; /* Return group to free list */
OSFlagFreeList = pgrp;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return ((OS_FLAG_GRP *)0); /* Event Flag Group has been deleted */
} else {
OS_EXIT_CRITICAL();
*err = OS_ERR_TASK_WAITING;
return (pgrp);
}
case OS_DEL_ALWAYS: /* Always delete the event flag group */
pnode = pgrp->OSFlagWaitList;
while (pnode != (OS_FLAG_NODE *)0) { /* Ready ALL tasks waiting for flags */
OS_FlagTaskRdy(pnode, (OS_FLAGS)0);
pnode = pnode->OSFlagNodeNext;
}
pgrp->OSFlagType = OS_EVENT_TYPE_UNUSED;
pgrp->OSFlagWaitList = (void *)OSFlagFreeList;/* Return group to free list */
OSFlagFreeList = pgrp;
OS_EXIT_CRITICAL();
if (tasks_waiting == TRUE) { /* Reschedule only if task(s) were waiting */
OS_Sched(); /* Find highest priority task ready to run */
}
*err = OS_NO_ERR;
return ((OS_FLAG_GRP *)0); /* Event Flag Group has been deleted */
default:
OS_EXIT_CRITICAL();
*err = OS_ERR_INVALID_OPT;
return (pgrp);
}
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* WAIT ON AN EVENT FLAG GROUP
*
* Description: This function is called to wait for a combination of bits to be set in an event flag
* group. Your application can wait for ANY bit to be set or ALL bits to be set.
*
* 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 wait for.
* 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 or ANY of the bits to be set.
* You can specify the following argument:
*
* OS_FLAG_WAIT_CLR_ALL You will wait for ALL bits in 'mask' to be clear (0)
* OS_FLAG_WAIT_SET_ALL You will wait for ALL bits in 'mask' to be set (1)
* OS_FLAG_WAIT_CLR_ANY You will wait for ANY bit in 'mask' to be clear (0)
* OS_FLAG_WAIT_SET_ANY You will wait for ANY bit in 'mask' 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
*
* timeout is an optional timeout (in clock ticks) that your task will wait for the
* desired bit combination. If you specify 0, however, your task will wait
* forever at the specified event flag group or, until a message arrives.
*
* err is a pointer to an error code and can be:
* OS_NO_ERR The desired bits have been set within the specified
* 'timeout'.
* OS_ERR_PEND_ISR If you tried to PEND from an ISR
* OS_FLAG_INVALID_PGRP If 'pgrp' is a NULL pointer.
* OS_ERR_EVENT_TYPE You are not pointing to an event flag group
* OS_TIMEOUT The bit(s) have not been set in the specified
* 'timeout'.
* OS_FLAG_ERR_WAIT_TYPE You didn't specify a proper 'wait_type' argument.
*
* Returns : The new state of the flags in the event flag group when the task is resumed or,
* 0 if a timeout or an error occurred.
*
* Called from: Task ONLY
*********************************************************************************************************
*/
OS_FLAGS OSFlagPend (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U wait_type, INT16U timeout, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_FLAG_NODE node;
OS_FLAGS flags_cur;
OS_FLAGS flags_rdy;
BOOLEAN consume;
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((OS_FLAGS)0);
}
#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*/
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 */
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
#if OS_TASKGROUP_EN > 0
OSTaskGroupTbl[OSTCBCur->OSTaskGroup] = 0xFF; /* Clear Task Group (yaxon add) */
#endif
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
#if OS_TASKGROUP_EN > 0
OS_Sched(); /* Find next highest priority task ready */
#endif
*err = OS_NO_ERR;
return (flags_cur);
} else { /* Block task until events occur or timeout */
OS_FlagBlock(pgrp, &node, flags, wait_type, timeout);
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 */
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
#if OS_TASKGROUP_EN > 0
OSTaskGroupTbl[OSTCBCur->OSTaskGroup] = 0xFF; /* Clear Task Group (yaxon add) */
#endif
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
#if OS_TASKGROUP_EN > 0
OS_Sched(); /* Find next highest priority task ready */
#endif
*err = OS_NO_ERR;
return (flags_cur);
} else { /* Block task until events occur or timeout */
OS_FlagBlock(pgrp, &node, flags, wait_type, timeout);
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 */
}
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