📄 os_mbox.lst
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C51 COMPILER V8.17 OS_MBOX 03/26/2009 14:24:24 PAGE 1
C51 COMPILER V8.17, COMPILATION OF MODULE OS_MBOX
OBJECT MODULE PLACED IN .\out-files\os_mbox.obj
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE uCOS II Files\os_mbox.c LARGE BROWSE INCDIR(.\smaRTC;.\SMBus) DEBUG OBJECTE
-XTEND PRINT(.\list-files\os_mbox.lst) TABS(2) OBJECT(.\out-files\os_mbox.obj)
line level source
1 /*
2 *********************************************************************************************************
3 * uC/OS-II
4 * The Real-Time Kernel
5 * MESSAGE MAILBOX MANAGEMENT
6 *
7 * (c) Copyright 1992-2007, Micrium, Weston, FL
8 * All Rights Reserved
9 *
10 * File : OS_MBOX.C
11 * By : Jean J. Labrosse
12 * Version : V2.86
13 *
14 * LICENSING TERMS:
15 * ---------------
16 * uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
-
17 * If you plan on using uC/OS-II in a commercial product you need to contact Micri祄 to properly license
18 * its use in your product. We provide ALL the source code for your convenience and to help you experience
19 * uC/OS-II. The fact that the source is provided does NOT mean that you can use it without paying a
20 * licensing fee.
21 *********************************************************************************************************
22 */
23
24 #ifndef OS_MASTER_FILE
25 #include "..\header files\includes.h"
26 #endif
27
28 #if OS_MBOX_EN > 0
/*
*********************************************************************************************************
* ACCEPT MESSAGE FROM MAILBOX
*
* Description: This function checks the mailbox to see if a message is available. Unlike OSMboxPend(),
* OSMboxAccept() 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 mailbox if one is available. The mailbox is cleared
* so the next time OSMboxAccept() is called, the mailbox will be empty.
* == (void *)0 if the mailbox is empty or,
* if 'pevent' is a NULL pointer or,
* if you didn't pass the proper event pointer.
*********************************************************************************************************
*/
#if OS_MBOX_ACCEPT_EN > 0
void *OSMboxAccept (OS_EVENT *pevent) reentrant
{
void *pmsg;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
C51 COMPILER V8.17 OS_MBOX 03/26/2009 14:24:24 PAGE 2
#if OS_ARG_CHK_EN > 0
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
return ((void *)0);
}
OS_ENTER_CRITICAL();
pmsg = pevent->OSEventPtr;
pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
OS_EXIT_CRITICAL();
return (pmsg); /* Return the message received (or NULL) */
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* CREATE A MESSAGE MAILBOX
*
* Description: This function creates a message mailbox if free event control blocks are available.
*
* Arguments : pmsg is a pointer to a message that you wish to deposit in the mailbox. If
* you set this value to the NULL pointer (i.e. (void *)0) then the mailbox
* will be considered empty.
*
* Returns : != (OS_EVENT *)0 is a pointer to the event control clock (OS_EVENT) associated with the
* created mailbox
* == (OS_EVENT *)0 if no event control blocks were available
*********************************************************************************************************
*/
OS_EVENT *OSMboxCreate (void *pmsg) reentrant
{
OS_EVENT *pevent;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
if (OSIntNesting > 0) { /* See if called from ISR ... */
return ((OS_EVENT *)0); /* ... can't CREATE from an ISR */
}
OS_ENTER_CRITICAL();
pevent = OSEventFreeList; /* Get next free event control block */
if (OSEventFreeList != (OS_EVENT *)0) { /* See if pool of free ECB pool was empty */
OSEventFreeList = (OS_EVENT *)OSEventFreeList->OSEventPtr;
}
OS_EXIT_CRITICAL();
if (pevent != (OS_EVENT *)0) {
pevent->OSEventType = OS_EVENT_TYPE_MBOX;
pevent->OSEventCnt = 0;
pevent->OSEventPtr = pmsg; /* Deposit message in event control block */
#if OS_EVENT_NAME_SIZE > 1
pevent->OSEventName[0] = '?';
pevent->OSEventName[1] = OS_ASCII_NUL;
#endif
OS_EventWaitListInit(pevent);
}
C51 COMPILER V8.17 OS_MBOX 03/26/2009 14:24:24 PAGE 3
return (pevent); /* Return pointer to event control block */
}
/*$PAGE*/
/*
*********************************************************************************************************
* DELETE A MAIBOX
*
* Description: This function deletes a mailbox and readies all tasks pending on the mailbox.
*
* Arguments : pevent is a pointer to the event control block associated with the desired
* mailbox.
*
* opt determines delete options as follows:
* opt == OS_DEL_NO_PEND Delete the mailbox ONLY if no task pending
* opt == OS_DEL_ALWAYS Deletes the mailbox even if tasks are waiting.
* In this case, all the tasks pending will be readied.
*
* perr is a pointer to an error code that can contain one of the following values:
* OS_ERR_NONE The call was successful and the mailbox was deleted
* OS_ERR_DEL_ISR If you attempted to delete the mailbox from an ISR
* OS_ERR_INVALID_OPT An invalid option was specified
* OS_ERR_TASK_WAITING One or more tasks were waiting on the mailbox
* OS_ERR_EVENT_TYPE If you didn't pass a pointer to a mailbox
* OS_ERR_PEVENT_NULL If 'pevent' is a NULL pointer.
*
* Returns : pevent upon error
* (OS_EVENT *)0 if the mailbox was successfully deleted.
*
* Note(s) : 1) This function must be used with care. Tasks that would normally expect the presence of
* the mailbox MUST check the return code of OSMboxPend().
* 2) OSMboxAccept() callers will not know that the intended mailbox has been deleted!
* 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 mailbox.
* 4) Because ALL tasks pending on the mailbox will be readied, you MUST be careful in
* applications where the mailbox is used for mutual exclusion because the resource(s)
* will no longer be guarded by the mailbox.
*********************************************************************************************************
*/
#if OS_MBOX_DEL_EN > 0
OS_EVENT *OSMboxDel (OS_EVENT *pevent, INT8U opt, INT8U *perr) reentrant
{
BOOLEAN tasks_waiting;
OS_EVENT *pevent_return;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0
if (perr == (INT8U *)0) { /* Validate 'perr' */
return (pevent);
}
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);
C51 COMPILER V8.17 OS_MBOX 03/26/2009 14:24:24 PAGE 4
}
if (OSIntNesting > 0) { /* See if called from ISR ... */
*perr = OS_ERR_DEL_ISR; /* ... can't DELETE from an ISR */
return (pevent);
}
OS_ENTER_CRITICAL();
if (pevent->OSEventGrp != 0) { /* 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_SIZE > 1
pevent->OSEventName[0] = '?'; /* Unknown name */
pevent->OSEventName[1] = OS_ASCII_NUL;
#endif
pevent->OSEventType = OS_EVENT_TYPE_UNUSED;
pevent->OSEventPtr = OSEventFreeList; /* Return Event Control Block to free list */
pevent->OSEventCnt = 0;
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;
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