?? os_q.lst
字號:
C51 COMPILER V8.05a OS_Q 04/11/2007 16:19:49 PAGE 1
C51 COMPILER V8.05a, COMPILATION OF MODULE OS_Q
OBJECT MODULE PLACED IN ..\Output\os_q.obj
COMPILER INVOKED BY: D:\Program Files\keil\C51\BIN\C51.EXE ..\SOURCE\os_q.c LARGE BROWSE INCDIR(..\app;..\Main;..\Port;.
-.\SOURCE) DEBUG OBJECTEXTEND PRINT(..\Output\os_q.lst) OBJECT(..\Output\os_q.obj)
line level source
1 /*
2 *********************************************************************************************************
3 * uC/OS-II
4 * The Real-Time Kernel
5 * MESSAGE QUEUE MANAGEMENT
6 *
7 * (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
8 * All Rights Reserved
9 *
10 * File : OS_Q.C
11 * By : Jean J. Labrosse
12 *********************************************************************************************************
13 */
14
15 #ifndef OS_MASTER_FILE
16 #include "includes.h"
17 #endif
18
19 #if (OS_Q_EN > 0) && (OS_MAX_QS > 0)
/*
*********************************************************************************************************
* 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
*
* err is a pointer to where an error message will be deposited. Possible error
* messages are:
*
* OS_NO_ERR The call was successful and your task received a
* message.
* OS_ERR_EVENT_TYPE You didn't pass a pointer to a queue
* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer
* OS_Q_EMPTY The queue did not contain any messages
*
* 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 you received a NULL pointer message
* if the queue is empty or,
* if 'pevent' is a NULL pointer or,
* if you passed an invalid event type
*
* Note(s) : As of V2.60, you can now pass NULL pointers through queues. Because of this, the argument
* 'err' has been added to the API to tell you about the outcome of the call.
*********************************************************************************************************
*/
#if OS_Q_ACCEPT_EN > 0
void *OSQAccept (OS_EVENT *pevent, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
C51 COMPILER V8.05a OS_Q 04/11/2007 16:19:49 PAGE 2
OS_CPU_SR cpu_sr;
#endif
void *msg;
OS_Q *pq;
#if OS_ARG_CHK_EN > 0
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*err = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type */
*err = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
OS_ENTER_CRITICAL();
pq = (OS_Q *)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;
}
*err = OS_NO_ERR;
} else {
*err = OS_Q_EMPTY;
msg = (void *)0; /* Queue is empty */
}
OS_EXIT_CRITICAL();
return (msg); /* Return message received (or NULL) */
}
#endif
/*$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 : != (OS_EVENT *)0 is a pointer to the event control clock (OS_EVENT) associated with the
* created queue
* == (OS_EVENT *)0 if no event control blocks were available or an error was detected
*********************************************************************************************************
*/
OS_EVENT *OSQCreate (void **start, INT16U size)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_EVENT *pevent;
OS_Q *pq;
C51 COMPILER V8.05a OS_Q 04/11/2007 16:19:49 PAGE 3
if (OSIntNesting > 0) { /* 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) { /* See if we have an event control block */
OS_ENTER_CRITICAL();
pq = OSQFreeList; /* Get a free queue control block */
if (pq != (OS_Q *)0) { /* Were we able to get a queue control block ? */
OSQFreeList = OSQFreeList->OSQPtr; /* Yes, Adjust free list pointer to next free*/
OS_EXIT_CRITICAL();
pq->OSQStart = start; /* 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->OSEventCnt = 0;
pevent->OSEventPtr = pq;
#if OS_EVENT_NAME_SIZE > 0
(void)strcpy(pevent->OSEventName, "?");
#endif
OS_EventWaitListInit(pevent); /* Initalize the wait list */
} else {
pevent->OSEventPtr = (void *)OSEventFreeList; /* No, Return event control block on error */
OSEventFreeList = pevent;
OS_EXIT_CRITICAL();
pevent = (OS_EVENT *)0;
}
}
return (pevent);
}
/*$PAGE*/
/*
*********************************************************************************************************
* DELETE A MESSAGE QUEUE
*
* Description: This function deletes a message queue and readies all tasks pending on the queue.
*
* Arguments : pevent is a pointer to the event control block associated with the desired
* queue.
*
* opt determines delete options as follows:
* opt == OS_DEL_NO_PEND Delete the queue ONLY if no task pending
* opt == OS_DEL_ALWAYS Deletes the queue 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 queue was deleted
* OS_ERR_DEL_ISR If you tried to delete the queue from an ISR
* OS_ERR_INVALID_OPT An invalid option was specified
* OS_ERR_TASK_WAITING One or more tasks were waiting on the queue
* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a queue
* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer.
*
* Returns : pevent upon error
* (OS_EVENT *)0 if the queue was successfully deleted.
C51 COMPILER V8.05a OS_Q 04/11/2007 16:19:49 PAGE 4
*
* Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
* the queue MUST check the return code of OSQPend().
* 2) OSQAccept() callers will not know that the intended queue has been deleted unless
* they check 'pevent' to see that it's a NULL pointer.
* 3) 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 queue.
* 4) Because ALL tasks pending on the queue will be readied, you MUST be careful in
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -