C51 COMPILER V7.10   OS_MEM                                                                10/17/2005 15:48:31 PAGE 1   


C51 COMPILER V7.10, COMPILATION OF MODULE OS_MEM
OBJECT MODULE PLACED IN .\OS_MEM.obj
COMPILER INVOKED BY: D:\Program Files\keil\C51\BIN\C51.EXE ..\uc_os_II\OS_MEM.C BROWSE DEBUG OBJECTEXTEND PRINT(.\OS_MEM
                    -.lst) OBJECT(.\OS_MEM.obj)

line level    source

   1          /*
   2          *********************************************************************************************************
   3          *                                                uC/OS-II
   4          *                                          The Real-Time Kernel
   5          *                                            MEMORY MANAGEMENT
   6          *
   7          *                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
   8          *                                           All Rights Reserved
   9          *
  10          *                                                  V2.00
  11          *
  12          * File : OS_MEM.C
  13          * By   : Jean J. Labrosse
  14          *********************************************************************************************************
  15          */
  16          
  17          #ifndef  OS_MASTER_FILE
  18          #include "includes.h"
  19          #endif
  20          
  21          #if OS_MEM_EN && OS_MAX_MEM_PART >= 2
              /*
              *********************************************************************************************************
              *                                         LOCAL GLOBAL VARIABLES
              *********************************************************************************************************
              */
              
              static  OS_MEM  DT_XDATA        *       DT_XDATA        OSMemFreeList;            /* Pointer to free list of memory partitions 
             -           */
              static  OS_MEM  DT_XDATA        OSMemTbl[OS_MAX_MEM_PART];/* Storage for memory partition manager                 
             -*/
              /*$PAGE*/
              /*
              *********************************************************************************************************
              *                                        CREATE A MEMORY PARTITION
              *
              * Description : Create a fixed-sized memory partition that will be managed by uC/OS-II.
              *
              * Arguments   : addr     is the starting address of the memory partition
              *
              *               nblks    is the number of memory blocks to create from the partition.
              *
              *               blksize  is the size (in bytes) of each block in the memory partition.
              *
              *               err      is a pointer to a variable containing an error message which will be set by
              *                        this function to either:
              *             
              *                        OS_NO_ERR            if the memory partition has been created correctly.
              *                        OS_MEM_INVALID_PART  no free partitions available
              *                        OS_MEM_INVALID_BLKS  user specified an invalid number of blocks (must be >= 2)
              *                        OS_MEM_INVALID_SIZE  user specified an invalid block size 
              *                                             (must be greater than the size of a pointer)
              * Returns    : != (OS_MEM *)0  is the partition was created 
              *              == (OS_MEM *)0  if the partition was not created because of invalid arguments or, no
C51 COMPILER V7.10   OS_MEM                                                                10/17/2005 15:48:31 PAGE 2   

              *                              free partition is available.
              *********************************************************************************************************
              */
              
              OS_MEM DT_XDATA *OSMemCreate (void DT_XDATA *addr, INT32U nblks, INT32U blksize, INT8U DT_XDATA *err) REEN
             -TRANT
              {
                  OS_MEM DT_XDATA *pmem;
                  INT8U  DT_XDATA *pblk;
                  void    DT_XDATA *  DT_XDATA * plink;
                  INT32U   i;
              
              
                  if (nblks < 2) {                                  /* Must have at least 2 blocks per partition      */
                      *err = OS_MEM_INVALID_BLKS;
                      return ((OS_MEM DT_XDATA *)0);
                  }
                  if (blksize < sizeof(void DT_XDATA *)) {                   /* Must contain space for at least a pointe
             -r      */
                      *err = OS_MEM_INVALID_SIZE;
                      return ((OS_MEM DT_XDATA *)0);
                  }
                  OS_ENTER_CRITICAL();
                  pmem = OSMemFreeList;                             /* Get next free memory partition                */
                  if (OSMemFreeList != (OS_MEM DT_XDATA *)0) {               /* See if pool of free partitions was empty
             -      */
                      OSMemFreeList = (OS_MEM DT_XDATA *)OSMemFreeList->OSMemFreeList;
                  }
                  OS_EXIT_CRITICAL();
                  if (pmem == (OS_MEM DT_XDATA *)0) {                        /* See if we have a memory partition       
             -      */
                      *err = OS_MEM_INVALID_PART;
                      return ((OS_MEM DT_XDATA *)0);
                  }
                  plink = (void DT_XDATA * DT_XDATA *)addr;                            /* Create linked list of free mem
             -ory blocks      */
                  pblk  = (INT8U DT_XDATA *)addr + blksize;
                  for (i = 0; i < (nblks - 1); i++) {
                      *plink = (void DT_XDATA *)pblk;
                      plink  = (void DT_XDATA * DT_XDATA *)pblk;
                      pblk   = pblk + blksize;
                  }
                  *plink = (void DT_XDATA *)0;                               /* Last memory block points to NULL        
             -      */
                  OS_ENTER_CRITICAL();
                  pmem->OSMemAddr     = addr;                       /* Store start address of memory partition       */
                  pmem->OSMemFreeList = addr;                       /* Initialize pointer to pool of free blocks     */
                  pmem->OSMemNFree    = nblks;                      /* Store number of free blocks in MCB            */
                  pmem->OSMemNBlks    = nblks;
                  pmem->OSMemBlkSize  = blksize;                    /* Store block size of each memory blocks        */
                  OS_EXIT_CRITICAL();
                  *err   = OS_NO_ERR;
                  return (pmem);
              }
              /*$PAGE*/
              /*
              *********************************************************************************************************
              *                                          GET A MEMORY BLOCK
              *
              * Description : Get a memory block from a partition
              *
              * Arguments   : pmem    is a pointer to the memory partition control block
C51 COMPILER V7.10   OS_MEM                                                                10/17/2005 15:48:31 PAGE 3   

              *
              *               err     is a pointer to a variable containing an error message which will be set by this
              *                       function to either:
              *
              *                       OS_NO_ERR           if the memory partition has been created correctly.
              *                       OS_MEM_NO_FREE_BLKS if there are no more free memory blocks to allocate to caller
              *
              * Returns     : A pointer to a memory block if no error is detected
              *               A pointer to NULL if an error is detected