COS-II_MSP430F2013程序

/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * MESSAGE QUEUE MANAGEMENT * * (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL * All Rights Reserved * * V2.00 * * File : OS_Q.C * By : Jean J. Labrosse ********************************************************************************************************* */ #ifndef OS_MASTER_FILE #include "includes.h" #endif #if OS_Q_EN && (OS_MAX_QS >= 2) /* ********************************************************************************************************* * LOCAL DATA TYPES ********************************************************************************************************* */ typedef struct os_q { /* QUEUE CONTROL BLOCK */ struct os_q *OSQPtr; /* Link to next queue control block in list of free blocks */ void **OSQStart; /* Pointer to start of queue data */ void **OSQEnd; /* Pointer to end of queue data */ void **OSQIn; /* Pointer to where next message will be inserted in the Q */ void **OSQOut; /* Pointer to where next message will be extracted from the Q */ INT16U OSQSize; /* Size of queue (maximum number of entries) */ INT16U OSQEntries; /* Current number of entries in the queue */ } OS_Q; /* ********************************************************************************************************* * LOCAL GLOBAL VARIABLES ********************************************************************************************************* */ static OS_Q *OSQFreeList; /* Pointer to list of free QUEUE control blocks */ static OS_Q OSQTbl[OS_MAX_QS]; /* Table of QUEUE control blocks */ /*$PAGE*/ /* ********************************************************************************************************* * ACCEPT MESSAGE FROM QUEUE * * Description: This function checks the queue to see if a message is available. Unlike OSQPend(), * OSQAccept() does not suspend the calling task if a message is not available. * * Arguments : pevent is a pointer to the event control block * * Returns : != (void *)0 is the message in the queue if one is available. The message is removed * from the so the next time OSQAccept() is called, the queue will contain * one less entry. * == (void *)0 if the queue is empty * if you passed an invalid event type ********************************************************************************************************* */ void *OSQAccept (OS_EVENT *pevent) { void *msg; OS_Q *pq; OS_ENTER_CRITICAL(); if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */ OS_EXIT_CRITICAL(); return ((void *)0); } pq = pevent->OSEventPtr; /* Point at queue control block */ if (pq->OSQEntries != 0) { /* See if any messages in the queue */ msg = *pq->OSQOut++; /* Yes, extract oldest message from the queue */ pq->OSQEntries--; /* Update the number of entries in the queue */ if (pq->OSQOut == pq->OSQEnd) { /* Wrap OUT pointer if we are at the end of the queue */ pq->OSQOut = pq->OSQStart; } } else { msg = (void *)0; /* Queue is empty */ } OS_EXIT_CRITICAL(); return (msg); /* Return message received (or NULL) */ } /*$PAGE*/ /* ********************************************************************************************************* * CREATE A MESSAGE QUEUE * * Description: This function creates a message queue if free event control blocks are available. * * Arguments : start is a pointer to the base address of the message queue storage area. The * storage area MUST be declared as an array of pointers to 'void' as follows * * void *MessageStorage[size] * * size is the number of elements in the storage area * * Returns : != (void *)0 is a pointer to the event control clock (OS_EVENT) associated with the * created queue * == (void *)0 if no event control blocks were available ********************************************************************************************************* */ OS_EVENT *OSQCreate (void **start, INT16U size) { OS_EVENT *pevent; OS_Q *pq; 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) { /* See if we have an event control block */ OS_ENTER_CRITICAL(); /* Get a free queue control block */ pq = OSQFreeList; if (OSQFreeList != (OS_Q *)0) { OSQFreeList = OSQFreeList->OSQPtr; } OS_EXIT_CRITICAL(); if (pq != (OS_Q *)0) { /* See if we were able to get a queue control block */ pq->OSQStart = start; /* Yes, initialize the queue */ pq->OSQEnd = &start[size]; pq->OSQIn = start; pq->OSQOut = start; pq->OSQSize = size; pq->OSQEntries = 0; pevent->OSEventType = OS_EVENT_TYPE_Q; pevent->OSEventPtr = pq; OSEventWaitListInit(pevent); } else { /* No, since we couldn't get a queue control block */ OS_ENTER_CRITICAL(); /* Return event control block on error */ pevent->OSEventPtr = (void *)OSEventFreeList; OSEventFreeList = pevent; OS_EXIT_CRITICAL(); pevent = (OS_EVENT *)0; } } return (pevent); } /*$PAGE*/ /* ********************************************************************************************************* * FLUSH QUEUE * * Description : This function is used to flush the contents of the message queue. * * Arguments : none * * Returns : OS_NO_ERR upon success * OS_ERR_EVENT_TYPE If you didn't pass a pointer to a queue ********************************************************************************************************* */ INT8U OSQFlush (OS_EVENT *pevent) { OS_Q *pq; OS_ENTER_CRITICAL(); if (pevent->OSEventType != OS_EVENT_TYPE_Q) { /* Validate event block type */ OS_EXIT_C