目录
消息邮箱创建
cpp
OS_EVENT *OSMboxCreate (void *pmsg)
{
OS_EVENT *pevent;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL_IEC61508
if (OSSafetyCriticalStartFlag == OS_TRUE)
{
OS_SAFETY_CRITICAL_EXCEPTION();
return ((OS_EVENT *)0);
}
#endif
if (OSIntNesting > 0u) /* See if called from ISR ... */
{
return ((OS_EVENT *)0); /* ... can't CREATE from an ISR */
}
OS_ENTER_CRITICAL();
pevent = OSEventFreeList; /* Get next free event control block */
if (OSEventFreeList != (OS_EVENT *)0) /* See if pool of free ECB pool was empty */
{
OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr;
}
OS_EXIT_CRITICAL();
if (pevent != (OS_EVENT *)0)
{
pevent->OSEventType = OS_EVENT_TYPE_MBOX;
pevent->OSEventCnt = 0u;
pevent->OSEventPtr = pmsg; /* Deposit message in event control block */
#if OS_EVENT_NAME_EN > 0u
pevent->OSEventName = (INT8U *) (void *)"?";
#endif
OS_EventWaitListInit (pevent);
}
return (pevent); /* Return pointer to event control block */
}消息邮箱删除
cpp
#if OS_MBOX_DEL_EN > 0u
OS_EVENT *OSMboxDel (OS_EVENT *pevent,
INT8U opt,
INT8U *perr)
{
BOOLEAN tasks_waiting;
OS_EVENT *pevent_return;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0)
{
OS_SAFETY_CRITICAL_EXCEPTION();
return ((OS_EVENT *)0);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (pevent == (OS_EVENT *)0) /* Validate 'pevent' */
{
*perr = OS_ERR_PEVENT_NULL;
return (pevent);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) /* Validate event block type */
{
*perr = OS_ERR_EVENT_TYPE;
return (pevent);
}
if (OSIntNesting > 0u) /* See if called from ISR ... */
{
*perr = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
return (pevent);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0u) /* See if any tasks waiting on mailbox */
{
tasks_waiting = OS_TRUE; /* Yes */
}
else
{
tasks_waiting = OS_FALSE; /* No */
}
switch (opt)
{
case OS_DEL_NO_PEND: /* Delete mailbox only if no task waiting */
if (tasks_waiting == OS_FALSE)
{
#if OS_EVENT_NAME_EN > 0u
pevent->OSEventName = (INT8U *) (void *)"?";
#endif
pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
pevent->OSEventCnt = 0u;
OSEventFreeList = pevent; /* Get next free event control block */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
pevent_return = (OS_EVENT *)0; /* Mailbox has been deleted */
}
else
{
OS_EXIT_CRITICAL();
*perr = OS_ERR_TASK_WAITING;
pevent_return = pevent;
}
break;
case OS_DEL_ALWAYS: /* Always delete the mailbox */
while (pevent->OSEventGrp != 0u) /* Ready ALL tasks waiting for mailbox */
{
(void)OS_EventTaskRdy (pevent, (void *)0, OS_STAT_MBOX, OS_STAT_PEND_ABORT);
}
#if OS_EVENT_NAME_EN > 0u
pevent->OSEventName = (INT8U *) (void *)"?";
#endif
pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
pevent->OSEventCnt = 0u;
OSEventFreeList = pevent; /* Get next free event control block */
OS_EXIT_CRITICAL();
if (tasks_waiting == OS_TRUE) /* Reschedule only if task(s) were waiting */
{
OS_Sched(); /* Find highest priority task ready to run */
}
*perr = OS_ERR_NONE;
pevent_return = (OS_EVENT *)0; /* Mailbox has been deleted */
break;
default:
OS_EXIT_CRITICAL();
*perr = OS_ERR_INVALID_OPT;
pevent_return = pevent;
break;
}
return (pevent_return);
}
#endif等待邮箱中的消息
cpp
void *OSMboxPend (OS_EVENT *pevent,
INT32U timeout,
INT8U *perr)
{
void *pmsg;
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#ifdef OS_SAFETY_CRITICAL
if (perr == (INT8U *)0)
{
OS_SAFETY_CRITICAL_EXCEPTION();
return ((void *)0);
}
#endif
#if OS_ARG_CHK_EN > 0u
if (pevent == (OS_EVENT *)0) /* Validate 'pevent' */
{
*perr = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) /* Validate event block type */
{
*perr = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
if (OSIntNesting > 0u) /* See if called from ISR ... */
{
*perr = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
if (OSLockNesting > 0u) /* See if called with scheduler locked ... */
{
*perr = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return ((void *)0);
}
OS_ENTER_CRITICAL();
pmsg = pevent->OSEventPtr;
if (pmsg != (void *)0) /* See if there is already a message */
{
pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (pmsg); /* Return the message received (or NULL) */
}
OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBDly = timeout; /* Load timeout in TCB */
OS_EventTaskWait (pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
OS_Sched(); /* Find next highest priority task ready to run */
OS_ENTER_CRITICAL();
switch (OSTCBCur->OSTCBStatPend) /* See if we timed-out or aborted */
{
case OS_STAT_PEND_OK:
pmsg = OSTCBCur->OSTCBMsg;
*perr = OS_ERR_NONE;
break;
case OS_STAT_PEND_ABORT:
pmsg = (void *)0;
*perr = OS_ERR_PEND_ABORT; /* Indicate that we aborted */
break;
case OS_STAT_PEND_TO:
default:
OS_EventTaskRemove (OSTCBCur, pevent);
pmsg = (void *)0;
*perr = OS_ERR_TIMEOUT; /* Indicate that we didn't get event within TO */
break;
}
OSTCBCur->OSTCBStat = OS_STAT_RDY; /* Set task status to ready */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK; /* Clear pend status */
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* Clear event pointers */
#if (OS_EVENT_MULTI_EN > 0u)
OSTCBCur->OSTCBEventMultiPtr = (OS_EVENT **)0;
#endif
OSTCBCur->OSTCBMsg = (void *)0; /* Clear received message */
OS_EXIT_CRITICAL();
return (pmsg); /* Return received message */
}向邮箱发送一则消息
cpp
#if OS_MBOX_POST_EN > 0u
INT8U OSMboxPost (OS_EVENT *pevent,
void *pmsg)
{
#if OS_CRITICAL_METHOD == 3u /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0u;
#endif
#if OS_ARG_CHK_EN > 0u
if (pevent == (OS_EVENT *)0) /* Validate 'pevent' */
{
return (OS_ERR_PEVENT_NULL);
}
if (pmsg == (void *)0) /* Make sure we are not posting a NULL pointer */
{
return (OS_ERR_POST_NULL_PTR);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) /* Validate event block type */
{
return (OS_ERR_EVENT_TYPE);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0u) /* See if any task pending on mailbox */
{
/* Ready HPT waiting on event */
(void)OS_EventTaskRdy (pevent, pmsg, OS_STAT_MBOX, OS_STAT_PEND_OK);
OS_EXIT_CRITICAL();
OS_Sched(); /* Find highest priority task ready to run */
return (OS_ERR_NONE);
}
if (pevent->OSEventPtr != (void *)0) /* Make sure mailbox doesn't already have a msg */
{
OS_EXIT_CRITICAL();
return (OS_ERR_MBOX_FULL);
}
pevent->OSEventPtr = pmsg; /* Place message in mailbox */
OS_EXIT_CRITICAL();
return (OS_ERR_NONE);
}
#endif