/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* EVENT FLAG MANAGEMENT
*
* (c) Copyright 2001-2002, 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 */
pgrp->OSFlagFlags |= flags_rdy; /* Set 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;
#endif
default:
OS_EXIT_CRITICAL();
flags_cur = (OS_FLAGS)0;
*err = OS_FLAG_ERR_WAIT_TYPE;
break;
}
return (flags_cur);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CREATE AN EVENT FLAG
*
* Description: This function is called to create an event flag group.
*
* Arguments : flags Contains the initial value to store in the event flag group.
*
* err is a pointer to an error code which will be returned to your application:
* OS_NO_ERR if the call was successful.
* OS_ERR_CREATE_ISR if you attempted to create an Event Flag from an
* ISR.
* OS_FLAG_GRP_DEPLETED if there are no more event flag groups
*
* Returns : A pointer to an event flag group or a NULL pointer if no more groups are available.
*
* Called from: Task ONLY
*********************************************************************************************************
*/
OS_FLAG_GRP *OSFlagCreate (OS_FLAGS flags, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_FLAG_GRP *pgrp;
if (OSIntNesting > 0) { /* See if called from ISR ... */
*err = OS_ERR_CREATE_ISR; /* ... can‘t CREATE from an ISR */
return ((OS_FLAG_GRP *)0);
}
OS_ENTER_CRITICAL();
pgrp = OSFlagFreeList; /* Get next free event flag */
if (pgrp != (OS_FLAG_GRP *)0) { /* See if we have event flag groups available */
/* Adjust free list */
OSFlagFreeList = (OS_FLAG_GRP *)OSFlagFreeList->OSFlagWaitList;
pgrp->OSFlagType = OS_EVENT_TYPE_FLAG; /* Set to event flag group type */
pgrp->OSFlagFlags = flags; /* Set to desired initial value */
pgrp->OSFlagWaitList = (void *)0; /* Clear list of tasks waiting on flags */
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
} else {
OS_EXIT_CRITICAL();
*err = OS_FLAG_GRP_DEPLETED;
}
return (pgrp); /* Return pointer to event flag group */
}
/*$PAGE*/
/*
*********************************************************************************************************
* DELETE AN EVENT FLAG GROUP
*
* Description: This function deletes an event flag group and readies all tasks pending on the event flag
* group.
*
* Arguments : pgrp is a pointer to the desired event flag group.
*
* opt determines delete options as follows:
* 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 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 = (OS_FLAG_NODE *)pgrp->OSFlagWaitList;
while (pnode != (OS_FLAG_NODE *)0) { /* Ready ALL tasks waiting for flags */
OS_FlagTaskRdy(pnode, (OS_FLAGS)0);
pnode = (OS_FLAG_NODE *)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 */
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
*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 */
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
*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 */
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
*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_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 */
pgrp->OSFlagFlags |= flags_rdy; /* Set ONLY the flags that we got */
}
flags_cur = pgrp->OSFlagFlags; /* Will return the state of the group */
OS_EXIT_CRITICAL(); /* Yes, condition met, return to caller */
*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;
#endif
default:
OS_EXIT_CRITICAL();
flags_cur = (OS_FLAGS)0;
*err = OS_FLAG_ERR_WAIT_TYPE;
return (flags_cur);
}
OS_Sched(); /* Find next HPT ready to run */
OS_ENTER_CRITICAL();
if (OSTCBCur->OSTCBStat & OS_STAT_FLAG) { /* Have we timed-out? */
OS_FlagUnlink(&node);
OSTCBCur->OSTCBStat = OS_STAT_RDY; /* Yes, make task ready-to-run */
OS_EXIT_CRITICAL();
flags_cur = (OS_FLAGS)0;
*err = OS_TIMEOUT; /* Indicate that we timed-out waiting */
} else {
if (consume == TRUE) { /* See if we need to consume the flags */
switch (wait_type) {
case OS_FLAG_WAIT_SET_ALL:
case OS_FLAG_WAIT_SET_ANY: /* Clear ONLY the flags we got */
pgrp->OSFlagFlags &= ~OSTCBCur->OSTCBFlagsRdy;
break;
#if OS_FLAG_WAIT_CLR_EN > 0
case OS_FLAG_WAIT_CLR_ALL:
case OS_FLAG_WAIT_CLR_ANY: /* Set ONLY the flags we got */
pgrp->OSFlagFlags |= OSTCBCur->OSTCBFlagsRdy;
break;
#endif
}
}
flags_cur = pgrp->OSFlagFlags;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR; /* Event(s) must have occurred */
}
return (flags_cur);
}
/*$PAGE*/
/*
*********************************************************************************************************
* POST EVENT FLAG BIT(S)
*
* Description: This function is called to set or clear some bits in an event flag group. The bits to
* set or clear are specified by a ‘bit mask‘.
*
* Arguments : pgrp is a pointer to the desired event flag group.
*
* flags If ‘opt‘ (see below) is OS_FLAG_SET, each bit that is set in ‘flags‘ will
* set the corresponding bit in the event flag group. e.g. to set bits 0, 4
* and 5 you would set ‘flags‘ to:
*
* 0x31 (note, bit 0 is least significant bit)
*
* If ‘opt‘ (see below) is OS_FLAG_CLR, each bit that is set in ‘flags‘ will
* CLEAR the corresponding bit in the event flag group. e.g. to clear bits 0,
* 4 and 5 you would specify ‘flags‘ as:
*
* 0x31 (note, bit 0 is least significant bit)
*
* opt indicates whether the flags will be:
* set (OS_FLAG_SET) or
* cleared (OS_FLAG_CLR)
*
* err is a pointer to an error code and can be:
* OS_NO_ERR The call was successfull
* OS_FLAG_INVALID_PGRP You passed a NULL pointer
* OS_ERR_EVENT_TYPE You are not pointing to an event flag group
* OS_FLAG_INVALID_OPT You specified an invalid option
*
* Returns : the new value of the event flags bits that are still set.
*
* Called From: Task or ISR
*
* WARNING(s) : 1) The execution time of this function depends on the number of tasks waiting on the event
* flag group.
* 2) The amount of time interrupts are DISABLED depends on the number of tasks waiting on
* the event flag group.
*********************************************************************************************************
*/
OS_FLAGS OSFlagPost (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U opt, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_FLAG_NODE *pnode;
BOOLEAN sched;
OS_FLAGS flags_cur;
OS_FLAGS flags_rdy;
#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) { /* Make sure we are pointing to an event flag grp */
*err = OS_ERR_EVENT_TYPE;
return ((OS_FLAGS)0);
}
#endif
/*$PAGE*/
OS_ENTER_CRITICAL();
switch (opt) {
case OS_FLAG_CLR:
pgrp->OSFlagFlags &= ~flags; /* Clear the flags specified in the group */
break;
case OS_FLAG_SET:
pgrp->OSFlagFlags |= flags; /* Set the flags specified in the group */
break;
default:
OS_EXIT_CRITICAL(); /* INVALID option */
*err = OS_FLAG_INVALID_OPT;
return ((OS_FLAGS)0);
}
sched = FALSE; /* Indicate that we don‘t need rescheduling */
pnode = (OS_FLAG_NODE *)pgrp->OSFlagWaitList;
while (pnode != (OS_FLAG_NODE *)0) { /* Go through all tasks waiting on event flag(s) */
switch (pnode->OSFlagNodeWaitType) {
case OS_FLAG_WAIT_SET_ALL: /* See if all req. flags are set for current node */
flags_rdy = pgrp->OSFlagFlags & pnode->OSFlagNodeFlags;
if (flags_rdy == pnode->OSFlagNodeFlags) {
if (OS_FlagTaskRdy(pnode, flags_rdy) == TRUE) { /* Make task RTR, event(s) Rx‘d */
sched = TRUE; /* When done we will reschedule */
}
}
break;
case OS_FLAG_WAIT_SET_ANY: /* See if any flag set */
flags_rdy = pgrp->OSFlagFlags & pnode->OSFlagNodeFlags;
if (flags_rdy != (OS_FLAGS)0) {
if (OS_FlagTaskRdy(pnode, flags_rdy) == TRUE) { /* Make task RTR, event(s) Rx‘d */
sched = TRUE; /* When done we will reschedule */
}
}
break;
#if OS_FLAG_WAIT_CLR_EN > 0
case OS_FLAG_WAIT_CLR_ALL: /* See if all req. flags are set for current node */
flags_rdy = ~pgrp->OSFlagFlags & pnode->OSFlagNodeFlags;
if (flags_rdy == pnode->OSFlagNodeFlags) {
if (OS_FlagTaskRdy(pnode, flags_rdy) == TRUE) { /* Make task RTR, event(s) Rx‘d */
sched = TRUE; /* When done we will reschedule */
}
}
break;
case OS_FLAG_WAIT_CLR_ANY: /* See if any flag set */
flags_rdy = ~pgrp->OSFlagFlags & pnode->OSFlagNodeFlags;
if (flags_rdy != (OS_FLAGS)0) {
if (OS_FlagTaskRdy(pnode, flags_rdy) == TRUE) { /* Make task RTR, event(s) Rx‘d */
sched = TRUE; /* When done we will reschedule */
}
}
break;
#endif
}
pnode = (OS_FLAG_NODE *)pnode->OSFlagNodeNext; /* Point to next task waiting for event flag(s) */
}
OS_EXIT_CRITICAL();
if (sched == TRUE) {
OS_Sched();
}
OS_ENTER_CRITICAL();
flags_cur = pgrp->OSFlagFlags;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (flags_cur);
}
/*$PAGE*/
/*
*********************************************************************************************************
* QUERY EVENT FLAG
*
* Description: This function is used to check the value of the event flag group.
*
* Arguments : pgrp is a pointer to the desired event flag group.
*
* err is a pointer to an error code returned to the called:
* OS_NO_ERR The call was successfull
* OS_FLAG_INVALID_PGRP You passed a NULL pointer
* OS_ERR_EVENT_TYPE You are not pointing to an event flag group
*
* Returns : The current value of the event flag group.
*
* Called From: Task or ISR
*********************************************************************************************************
*/
#if OS_FLAG_QUERY_EN > 0
OS_FLAGS OSFlagQuery (OS_FLAG_GRP *pgrp, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_FLAGS flags;
#if OS_ARG_CHK_EN > 0
if (pgrp == (OS_FLAG_GRP *)0) { /* Validate ‘pgrp‘ */
*err = OS_FLAG_INVALID_PGRP;
return ((OS_FLAGS)0);
}
if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) { /* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((OS_FLAGS)0);
}
#endif
OS_ENTER_CRITICAL();
flags = pgrp->OSFlagFlags;
OS_EXIT_CRITICAL();
*err = OS_NO_ERR;
return (flags); /* Return the current value of the event flags */
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* SUSPEND TASK UNTIL EVENT FLAG(s) RECEIVED OR TIMEOUT OCCURS
*
* Description: This function is internal to uC/OS-II and is used to put a task to sleep until the desired
* event flag bit(s) are set.
*
* Arguments : pgrp is a pointer to the desired event flag group.
*
* pnode is a pointer to a structure which contains data about the task waiting for
* event flag bit(s) to be set.
*
* 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 ‘mask‘ to be clear (0)
* OS_FLAG_WAIT_CLR_ANY You will check ANY bit in ‘mask‘ to be clear (0)
* OS_FLAG_WAIT_SET_ALL You will check ALL bits in ‘mask‘ to be set (1)
* OS_FLAG_WAIT_SET_ANY You will check ANY bit in ‘mask‘ to be set (1)
*
* timeout is the desired amount of time that the task will wait for the event flag
* bit(s) to be set.
*
* Returns : none
*
* Called by : OSFlagPend() OS_FLAG.C
*
* Note(s) : This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
static void OS_FlagBlock (OS_FLAG_GRP *pgrp, OS_FLAG_NODE *pnode, OS_FLAGS flags, INT8U wait_type, INT16U timeout)
{
OS_FLAG_NODE *pnode_next;
OSTCBCur->OSTCBStat |= OS_STAT_FLAG;
OSTCBCur->OSTCBDly = timeout; /* Store timeout in task‘s TCB */
#if OS_TASK_DEL_EN > 0
OSTCBCur->OSTCBFlagNode = pnode; /* TCB to link to node */
#endif
pnode->OSFlagNodeFlags = flags; /* Save the flags that we need to wait for */
pnode->OSFlagNodeWaitType = wait_type; /* Save the type of wait we are doing */
pnode->OSFlagNodeTCB = (void *)OSTCBCur; /* Link to task‘s TCB */
pnode->OSFlagNodeNext = pgrp->OSFlagWaitList; /* Add node at beginning of event flag wait list */
pnode->OSFlagNodePrev = (void *)0;
pnode->OSFlagNodeFlagGrp = (void *)pgrp; /* Link to Event Flag Group */
pnode_next = (OS_FLAG_NODE *)pgrp->OSFlagWaitList;
if (pnode_next != (void *)0) { /* Is this the first NODE to insert? */
pnode_next->OSFlagNodePrev = pnode; /* No, link in doubly linked list */
}
pgrp->OSFlagWaitList = (void *)pnode;
/* Suspend current task until flag(s) received */
if ((OSRdyTbl[OSTCBCur->OSTCBY] &= ~OSTCBCur->OSTCBBitX) == 0) {
OSRdyGrp &= ~OSTCBCur->OSTCBBitY;
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* INITIALIZE THE EVENT FLAG MODULE
*
* Description: This function is called by uC/OS-II to initialize the event flag module. Your application
* MUST NOT call this function. In other words, this function is internal to uC/OS-II.
*
* Arguments : none
*
* Returns : none
*
* WARNING : You MUST NOT call this function from your code. This is an INTERNAL function to uC/OS-II.
*********************************************************************************************************
*/
//初始化标志控制块缓冲池
void OS_FlagInit (void)
{
#if OS_MAX_FLAGS == 1
OSFlagFreeList = (OS_FLAG_GRP *)&OSFlagTbl[0]; /* Only ONE event flag group! */
OSFlagFreeList->OSFlagType = OS_EVENT_TYPE_UNUSED;
OSFlagFreeList->OSFlagWaitList = (void *)0;
#endif
#if OS_MAX_FLAGS >= 2
INT8U i;
OS_FLAG_GRP *pgrp1;
OS_FLAG_GRP *pgrp2;
pgrp1 = &OSFlagTbl[0];
pgrp2 = &OSFlagTbl[1];
for (i = 0; i < (OS_MAX_FLAGS - 1); i++) { /* Init. list of free EVENT FLAGS */
pgrp1->OSFlagType = OS_EVENT_TYPE_UNUSED;
pgrp1->OSFlagWaitList = (void *)pgrp2;
pgrp1++;
pgrp2++;
}
pgrp1->OSFlagWaitList = (void *)0;
OSFlagFreeList = (OS_FLAG_GRP *)&OSFlagTbl[0];
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* MAKE TASK READY-TO-RUN, EVENT(s) OCCURRED
*
* Description: This function is internal to uC/OS-II and is used to make a task ready-to-run because the
* desired event flag bits have been set.
*
* Arguments : pnode is a pointer to a structure which contains data about the task waiting for
* event flag bit(s) to be set.
*
* flags_rdy contains the bit pattern of the event flags that cause the task to become
* ready-to-run.
*
* Returns : none
*
* Called by : OSFlagsPost() OS_FLAG.C
*
* Note(s) : 1) This function assumes that interrupts are disabled.
* 2) This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
static BOOLEAN OS_FlagTaskRdy (OS_FLAG_NODE *pnode, OS_FLAGS flags_rdy)
{
OS_TCB *ptcb;
BOOLEAN sched;
ptcb = (OS_TCB *)pnode->OSFlagNodeTCB; /* Point to TCB of waiting task */
ptcb->OSTCBDly = 0;
ptcb->OSTCBFlagsRdy = flags_rdy;
ptcb->OSTCBStat &= ~OS_STAT_FLAG;
if (ptcb->OSTCBStat == OS_STAT_RDY) { /* Put task into ready list */
OSRdyGrp |= ptcb->OSTCBBitY;
OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
sched = TRUE;
} else {
sched = FALSE;
}
OS_FlagUnlink(pnode);
return (sched);
}
/*$PAGE*/
/*
*********************************************************************************************************
* UNLINK EVENT FLAG NODE FROM WAITING LIST
*
* Description: This function is internal to uC/OS-II and is used to unlink an event flag node from a
* list of tasks waiting for the event flag.
*
* Arguments : pnode is a pointer to a structure which contains data about the task waiting for
* event flag bit(s) to be set.
*
* Returns : none
*
* Called by : OS_FlagTaskRdy() OS_FLAG.C
* OSFlagPend() OS_FLAG.C
* OSTaskDel() OS_TASK.C
*
* Note(s) : 1) This function assumes that interrupts are disabled.
* 2) This function is INTERNAL to uC/OS-II and your application should not call it.
*********************************************************************************************************
*/
void OS_FlagUnlink (OS_FLAG_NODE *pnode)
{
#if OS_TASK_DEL_EN > 0
OS_TCB *ptcb;
#endif
OS_FLAG_GRP *pgrp;
OS_FLAG_NODE *pnode_prev;
OS_FLAG_NODE *pnode_next;
pnode_prev = (OS_FLAG_NODE *)pnode->OSFlagNodePrev;
pnode_next = (OS_FLAG_NODE *)pnode->OSFlagNodeNext;
if (pnode_prev == (OS_FLAG_NODE *)0) { /* Is it first node in wait list? */
pgrp = (OS_FLAG_GRP *)pnode->OSFlagNodeFlagGrp;
pgrp->OSFlagWaitList = (void *)pnode_next; /* Update list for new 1st node */
if (pnode_next != (OS_FLAG_NODE *)0) {
pnode_next->OSFlagNodePrev = (OS_FLAG_NODE *)0; /* Link new 1st node PREV to NULL */
}
} else { /* No, A node somewhere in the list */
pnode_prev->OSFlagNodeNext = pnode_next; /* Link around the node to unlink */
if (pnode_next != (OS_FLAG_NODE *)0) { /* Was this the LAST node? */
pnode_next->OSFlagNodePrev = pnode_prev; /* No, Link around current node */
}
}
#if OS_TASK_DEL_EN > 0
ptcb = (OS_TCB *)pnode->OSFlagNodeTCB;
ptcb->OSTCBFlagNode = (OS_FLAG_NODE *)0;
#endif
}
#endif