os_mem.c - This C code implements a memory partition manage…

/src/compiler/ucos-vs2008/UCOS_SIM/src/ucosii/os_mem.c

http://ftk.googlecode.com/ · C · 416 lines · 236 code · 33 blank · 147 comment · 47 complexity · 4ede0aceb00ba5b25452cacc4c96986d MD5 · raw file

/*

*********************************************************************************************************

*                                                uC/OS-II

*                                          The Real-Time Kernel

*                                            MEMORY MANAGEMENT

*

*                          (c) Copyright 1992-2005, Jean J. Labrosse, Weston, FL

*                                           All Rights Reserved

*

* File    : OS_MEM.C

* By      : Jean J. Labrosse

* Version : V2.80

*********************************************************************************************************

*/



#ifndef  OS_MASTER_FILE

#include <ucos_ii.h>

#endif



#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)

/*

*********************************************************************************************************

*                                        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_ADDR  you are specifying an invalid address for the memory

*                                             storage of the partition.

*                        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

*                              free partition is available.

*********************************************************************************************************

*/



OS_MEM  *OSMemCreate (void *addr, INT32U nblks, INT32U blksize, INT8U *err)

{

    OS_MEM    *pmem;

    INT8U     *pblk;

    void     **plink;

    INT32U     i;

#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 (err == (INT8U *)0) {                          /* Validate 'err'                                */

        return ((OS_MEM *)0);

    }

    if (addr == (void *)0) {                          /* Must pass a valid address for the memory part.*/

        *err = OS_MEM_INVALID_ADDR;

        return ((OS_MEM *)0);

    }

    if (nblks < 2) {                                  /* Must have at least 2 blocks per partition     */

        *err = OS_MEM_INVALID_BLKS;

        return ((OS_MEM *)0);

    }

    if (blksize < sizeof(void *)) {                   /* Must contain space for at least a pointer     */

        *err = OS_MEM_INVALID_SIZE;

        return ((OS_MEM *)0);

    }

#endif

    OS_ENTER_CRITICAL();

    pmem = OSMemFreeList;                             /* Get next free memory partition                */

    if (OSMemFreeList != (OS_MEM *)0) {               /* See if pool of free partitions was empty      */

        OSMemFreeList = (OS_MEM *)OSMemFreeList->OSMemFreeList;

    }

    OS_EXIT_CRITICAL();

    if (pmem == (OS_MEM *)0) {                        /* See if we have a memory partition             */

        *err = OS_MEM_INVALID_PART;

        return ((OS_MEM *)0);

    }

    plink = (void **)addr;                            /* Create linked list of free memory blocks      */

    pblk  = (INT8U *)((INT32U)addr + blksize);

    for (i = 0; i < (nblks - 1); i++) {

       *plink = (void *)pblk;                         /* Save pointer to NEXT block in CURRENT block   */

        plink = (void **)pblk;                        /* Position to  NEXT      block                  */

        pblk  = (INT8U *)((INT32U)pblk + blksize);    /* Point to the FOLLOWING block                  */

    }

    *plink              = (void *)0;                  /* Last memory block points to NULL              */

    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        */

    *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

*

*               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

*                       OS_MEM_INVALID_PMEM if you passed a NULL pointer for 'pmem'

*

* Returns     : A pointer to a memory block if no error is detected

*               A pointer to NULL if an error is detected

*********************************************************************************************************

*/



void  *OSMemGet (OS_MEM *pmem, INT8U *err)

{

    void      *pblk;

#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 (err == (INT8U *)0) {                          /* Validate 'err'                                */

        return ((void *)0);

    }

    if (pmem == (OS_MEM *)0) {                        /* Must point to a valid memory partition        */

        *err = OS_MEM_INVALID_PMEM;

        return ((void *)0);

    }

#endif

    OS_ENTER_CRITICAL();

    if (pmem->OSMemNFree > 0) {                       /* See if there are any free memory blocks       */

        pblk                = pmem->OSMemFreeList;    /* Yes, point to next free memory block          */

        pmem->OSMemFreeList = *(void **)pblk;         /*      Adjust pointer to new free list          */

        pmem->OSMemNFree--;                           /*      One less memory block in this partition  */

        OS_EXIT_CRITICAL();

        *err = OS_NO_ERR;                             /*      No error                                 */

        return (pblk);                                /*      Return memory block to caller            */

    }

    OS_EXIT_CRITICAL();

    *err = OS_MEM_NO_FREE_BLKS;                       /* No,  Notify caller of empty memory partition  */

    return ((void *)0);                               /*      Return NULL pointer to caller            */

}

/*$PAGE*/

/*

*********************************************************************************************************

*                                   GET THE NAME OF A MEMORY PARTITION

*

* Description: This function is used to obtain the name assigned to a memory partition.

*

* Arguments  : pmem      is a pointer to the memory partition

*

*              pname     is a pointer to an ASCII string that will receive the name of the memory partition.

*

*              err       is a pointer to an error code that can contain one of the following values:

*

*                        OS_NO_ERR                  if the name was copied to 'pname'

*                        OS_MEM_INVALID_PMEM        if you passed a NULL pointer for 'pmem'

*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'

*

* Returns    : The length of the string or 0 if 'pmem' is a NULL pointer.

*********************************************************************************************************

*/



#if OS_MEM_NAME_SIZE > 1

INT8U  OSMemNameGet (OS_MEM *pmem, INT8U *pname, INT8U *err)

{

    INT8U      len;

#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */

    OS_CPU_SR  cpu_sr = 0;

#endif







    OS_ENTER_CRITICAL();

#if OS_ARG_CHK_EN > 0

    if (err == (INT8U *)0) {                     /* Validate 'err'                                     */

        OS_EXIT_CRITICAL();

        return (0);

    }

    if (pmem == (OS_MEM *)0) {                   /* Is 'pmem' a NULL pointer?                          */

        OS_EXIT_CRITICAL();                      /* Yes                                                */

        *err = OS_MEM_INVALID_PMEM;

        return (0);

    }

    if (pname == (INT8U *)0) {                    /* Is 'pname' a NULL pointer?                         */

        OS_EXIT_CRITICAL();                      /* Yes                                                */

        *err = OS_ERR_PNAME_NULL;

        return (0);

    }

#endif

    len  = OS_StrCopy(pname, pmem->OSMemName);   /* Copy name from OS_MEM                              */

    OS_EXIT_CRITICAL();

    *err = OS_NO_ERR;

    return (len);

}

#endif



/*$PAGE*/

/*

*********************************************************************************************************

*                                 ASSIGN A NAME TO A MEMORY PARTITION

*

* Description: This function assigns a name to a memory partition.

*

* Arguments  : pmem      is a pointer to the memory partition

*

*              pname     is a pointer to an ASCII string that contains the name of the memory partition.

*

*              err       is a pointer to an error code that can contain one of the following values:

*

*                        OS_NO_ERR                  if the name was copied to 'pname'

*                        OS_MEM_INVALID_PMEM        if you passed a NULL pointer for 'pmem'

*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'

*						 OS_MEM_NAME_TOO_LONG       if the name doesn't fit in the storage area

*

* Returns    : None

*********************************************************************************************************

*/



#if OS_MEM_NAME_SIZE > 1

void  OSMemNameSet (OS_MEM *pmem, INT8U *pname, INT8U *err)

{

    INT8U      len;

#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */

    OS_CPU_SR  cpu_sr = 0;

#endif







    OS_ENTER_CRITICAL();

#if OS_ARG_CHK_EN > 0

    if (err == (INT8U *)0) {                     /* Validate 'err'                                     */

        OS_EXIT_CRITICAL();

        return;

    }

    if (pmem == (OS_MEM *)0) {                   /* Is 'pmem' a NULL pointer?                          */

        OS_EXIT_CRITICAL();                      /* Yes                                                */

        *err = OS_MEM_INVALID_PMEM;

        return;

    }

    if (pname == (INT8U *)0) {                    /* Is 'pname' a NULL pointer?                         */

        OS_EXIT_CRITICAL();                      /* Yes                                                */

        *err = OS_ERR_PNAME_NULL;

        return;

    }

#endif

    len = OS_StrLen(pname);                      /* Can we fit the string in the storage area?         */

    if (len > (OS_MEM_NAME_SIZE - 1)) {          /* No                                                 */

        OS_EXIT_CRITICAL();

        *err = OS_MEM_NAME_TOO_LONG;

        return;

    }

    (void)OS_StrCopy(pmem->OSMemName, pname);    /* Yes, copy name to the memory partition header      */

    OS_EXIT_CRITICAL();

    *err = OS_NO_ERR;

}

#endif



/*$PAGE*/

/*

*********************************************************************************************************

*                                         RELEASE A MEMORY BLOCK

*

* Description : Returns a memory block to a partition

*

* Arguments   : pmem    is a pointer to the memory partition control block

*

*               pblk    is a pointer to the memory block being released.

*

* Returns     : OS_NO_ERR            if the memory block was inserted into the partition

*               OS_MEM_FULL          if you are returning a memory block to an already FULL memory

*                                    partition (You freed more blocks than you allocated!)

*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'

*               OS_MEM_INVALID_PBLK  if you passed a NULL pointer for the block to release.

*********************************************************************************************************

*/



INT8U  OSMemPut (OS_MEM *pmem, void *pblk)

{

#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 (pmem == (OS_MEM *)0) {                   /* Must point to a valid memory partition             */

        return (OS_MEM_INVALID_PMEM);

    }

    if (pblk == (void *)0) {                     /* Must release a valid block                         */

        return (OS_MEM_INVALID_PBLK);

    }

#endif

    OS_ENTER_CRITICAL();

    if (pmem->OSMemNFree >= pmem->OSMemNBlks) {  /* Make sure all blocks not already returned          */

        OS_EXIT_CRITICAL();

        return (OS_MEM_FULL);

    }

    *(void **)pblk      = pmem->OSMemFreeList;   /* Insert released block into free block list         */

    pmem->OSMemFreeList = pblk;

    pmem->OSMemNFree++;                          /* One more memory block in this partition            */

    OS_EXIT_CRITICAL();

    return (OS_NO_ERR);                          /* Notify caller that memory block was released       */

}

/*$PAGE*/

/*

*********************************************************************************************************

*                                          QUERY MEMORY PARTITION

*

* Description : This function is used to determine the number of free memory blocks and the number of

*               used memory blocks from a memory partition.

*

* Arguments   : pmem        is a pointer to the memory partition control block

*

*               p_mem_data  is a pointer to a structure that will contain information about the memory

*                           partition.

*

* Returns     : OS_NO_ERR            If no errors were found.

*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'

*               OS_MEM_INVALID_PDATA if you passed a NULL pointer to the data recipient.

*********************************************************************************************************

*/



#if OS_MEM_QUERY_EN > 0

INT8U  OSMemQuery (OS_MEM *pmem, OS_MEM_DATA *p_mem_data)

{

#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 (pmem == (OS_MEM *)0) {                   /* Must point to a valid memory partition             */

        return (OS_MEM_INVALID_PMEM);

    }

    if (p_mem_data == (OS_MEM_DATA *)0) {        /* Must release a valid storage area for the data     */

        return (OS_MEM_INVALID_PDATA);

    }

#endif

    OS_ENTER_CRITICAL();

    p_mem_data->OSAddr     = pmem->OSMemAddr;

    p_mem_data->OSFreeList = pmem->OSMemFreeList;

    p_mem_data->OSBlkSize  = pmem->OSMemBlkSize;

    p_mem_data->OSNBlks    = pmem->OSMemNBlks;

    p_mem_data->OSNFree    = pmem->OSMemNFree;

    OS_EXIT_CRITICAL();

    p_mem_data->OSNUsed    = p_mem_data->OSNBlks - p_mem_data->OSNFree;

    return (OS_NO_ERR);

}

#endif                                           /* OS_MEM_QUERY_EN                                    */

/*$PAGE*/

/*

*********************************************************************************************************

*                                    INITIALIZE MEMORY PARTITION MANAGER

*

* Description : This function is called by uC/OS-II to initialize the memory partition manager.  Your

*               application MUST NOT call this function.

*

* Arguments   : none

*

* Returns     : none

*

* Note(s)    : This function is INTERNAL to uC/OS-II and your application should not call it.

*********************************************************************************************************

*/



void  OS_MemInit (void)

{

#if OS_MAX_MEM_PART == 1

    OS_MemClr((INT8U *)&OSMemTbl[0], sizeof(OSMemTbl));   /* Clear the memory partition table          */

    OSMemFreeList               = (OS_MEM *)&OSMemTbl[0]; /* Point to beginning of free list           */

#if OS_MEM_NAME_SIZE > 1

    OSMemFreeList->OSMemName[0] = '?';                    /* Unknown name                              */

    OSMemFreeList->OSMemName[1] = OS_ASCII_NUL;

#endif

#endif



#if OS_MAX_MEM_PART >= 2

    OS_MEM  *pmem;

    INT16U   i;





    OS_MemClr((INT8U *)&OSMemTbl[0], sizeof(OSMemTbl));   /* Clear the memory partition table          */

    pmem = &OSMemTbl[0];                                  /* Point to memory control block (MCB)       */

    for (i = 0; i < (OS_MAX_MEM_PART - 1); i++) {         /* Init. list of free memory partitions      */

        pmem->OSMemFreeList = (void *)&OSMemTbl[i+1];     /* Chain list of free partitions             */

#if OS_MEM_NAME_SIZE > 1

        pmem->OSMemName[0]  = '?';                        /* Unknown name                              */

        pmem->OSMemName[1]  = OS_ASCII_NUL;

#endif

        pmem++;

    }

    pmem->OSMemFreeList = (void *)0;                      /* Initialize last node                      */

#if OS_MEM_NAME_SIZE > 1

    pmem->OSMemName[0]  = '?';                            /* Unknown name                              */

    pmem->OSMemName[1]  = OS_ASCII_NUL;

#endif



    OSMemFreeList       = &OSMemTbl[0];                   /* Point to beginning of free list           */

#endif

}

#endif                                                    /* OS_MEM_EN                                 */