C51 COMPILER V7.06   OS_MBOX                                                               03/04/2005 14:28:18 PAGE 1   


C51 COMPILER V7.06, COMPILATION OF MODULE OS_MBOX
OBJECT MODULE PLACED IN .\OS_MBOX.obj
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE ..\uc_os_II\OS_MBOX.C BROWSE DEBUG OBJECTEXTEND PRINT(.\OS_MBOX.lst) OBJECT
                    -(.\OS_MBOX.obj)

stmt level    source

   1          /*
   2          *********************************************************************************************************
   3          *                                                uC/OS-II
   4          *                                          The Real-Time Kernel
   5          *                                       MESSAGE MAILBOX MANAGEMENT
   6          *
   7          *                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
   8          *                                           All Rights Reserved
   9          *
  10          *                                                  V2.00
  11          *
  12          * File : OS_MBOX.C
  13          * By   : Jean J. Labrosse
  14          *********************************************************************************************************
  15          */
  16          
  17          #ifndef  OS_MASTER_FILE
  18          #include "includes.h"
  19          #endif
  20          
  21          #if OS_MBOX_EN
              /*
              *********************************************************************************************************
              *                                     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 you didn't pass the proper event pointer.
              *********************************************************************************************************
              */
              
              void DT_XDATA *OSMboxAccept (OS_EVENT DT_XDATA * pevent) REENTRANT
              {
                  void DT_XDATA * msg;
              
              
                  OS_ENTER_CRITICAL();
                  if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {      /* Validate event block type                 */
                      OS_EXIT_CRITICAL();
                      return ((void DT_XDATA *)0);
                  }
                  msg = pevent->OSEventPtr; 
                  if (msg != (void DT_XDATA *)0) {                               /* See if there is already a message   
             -      */
                      pevent->OSEventPtr = (void DT_XDATA *)0;                   /* Clear the mailbox                   
             -      */
                  }
                  OS_EXIT_CRITICAL();
                  return (msg);                                         /* Return the message received (or NULL)     */
C51 COMPILER V7.06   OS_MBOX                                                               03/04/2005 14:28:18 PAGE 2   

              }
              /*$PAGE*/
              /*
              *********************************************************************************************************
              *                                        CREATE A MESSAGE MAILBOX
              *
              * Description: This function creates a message mailbox if free event control blocks are available.
              *
              * Arguments  : msg           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    : != (void *)0  is a pointer to the event control clock (OS_EVENT) associated with the
              *                            created mailbox
              *              == (void *)0  if no event control blocks were available
              *********************************************************************************************************
              */
              
              OS_EVENT DT_XDATA *OSMboxCreate (void DT_XDATA * msg) REENTRANT
              {
                  OS_EVENT DT_XDATA *pevent;
              
              
                  OS_ENTER_CRITICAL();
                  pevent = OSEventFreeList;                    /* Get next free event control block                  */
                  if (OSEventFreeList != (OS_EVENT DT_XDATA *)0) {      /* See if pool of free ECB pool was empty       
             -      */
                      OSEventFreeList = (OS_EVENT DT_XDATA *)OSEventFreeList->OSEventPtr;
                  }
                  OS_EXIT_CRITICAL();
                  if (pevent != (OS_EVENT DT_XDATA *)0) {
                      pevent->OSEventType = OS_EVENT_TYPE_MBOX;
                      pevent->OSEventPtr  = msg;               /* Deposit message in event control block             */
                      OSEventWaitListInit(pevent);
                  }
                  return (pevent);                             /* Return pointer to event control block              */
              }
              /*$PAGE*/
              /*
              *********************************************************************************************************
              *                                      PEND ON MAILBOX FOR A MESSAGE
              *
              * Description: This function waits for a message to be sent to a mailbox
              *
              * Arguments  : pevent        is a pointer to the event control block associated with the desired mailbox
              *
              *              timeout       is an optional timeout period (in clock ticks).  If non-zero, your task will
              *                            wait for a message to arrive at the mailbox up to the amount of time 
              *                            specified by this argument.  If you specify 0, however, your task will wait 
              *                            forever at the specified mailbox or, until a message arrives.
              *
              *              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_TIMEOUT        A message was not received within the specified timeout
              *                            OS_ERR_EVENT_TYPE Invalid event type
              *                            OS_ERR_PEND_ISR   If you called this function from an ISR and the result
              *                                              would lead to a suspension.
              *
              * Returns    : != (void *)0  is a pointer to the message received
              *              == (void *)0  if no message was received or you didn't pass the proper pointer to the
C51 COMPILER V7.06   OS_MBOX                                                               03/04/2005 14:28:18 PAGE 3   

              *                            event control block.
              *********************************************************************************************************
              */
              
              void DT_XDATA *OSMboxPend (OS_EVENT DT_XDATA *pevent, INT16U timeout, INT8U DT_XDATA *err) REENTRANT
              {
                  void DT_XDATA *msg;
              
              
                  OS_ENTER_CRITICAL();
                  if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) {  /* Validate event block type                     */
                      OS_EXIT_CRITICAL();
                      *err = OS_ERR_EVENT_TYPE;
                      return ((void DT_XDATA *)0);
                  }