nufp.c

基于nucleus操作系统的GPRS无线数据传输终端全套源文件。包括支持ARM7的BSP,操作系统

/************************************************************************
*                                                                       
*       Copyright (c) 2001 by Accelerated Technology, Inc.              
*                                                                       
*  PROPRIETARY RIGHTS of Accelerated Technology are  involved in        
*  the subject matter of this material.  All manufacturing,             
*  reproduction, use, and sales rights pertaining to this subject       
*  matter are  governed by the license agreement.  The recipient of     
*     this software implicitly accepts the terms of the license.        
*                                                                       
*                                                                       
*************************************************************************

*************************************************************************
* FILE NAME                                     VERSION                 
*                                                                       
*       NUFP.C                                  FILE  2.3              
*                                                                       
* COMPONENT                                                             
*                                                                       
*       Nucleus File                                                    
*                                                                       
* DESCRIPTION                                                           
*                                                                       
*       This file contains the routines necessary to intitialize        
*       the Nucleus PLUS environment for file system usage.             
*                                                                       
* DATA STRUCTURES                                                       
*                                                                       
*       NUFP_TASK_POINTER                    Task ID list.              
*                                                                       
* FUNCTIONS                                                             
*                                                                       
*       NUFP_Current_Task_ID                Replaces the Nucleus PLUS   
*                                            Task Pointer to a Task ID. 
*       NUFP_Remove_User                    Responsible from removing a 
*                                            user from the              
*                                            NUFP_TASK_POINTER table.   
*                                                                       
* DEPENDENCIES                                                          
*                                                                       
*       nucleus.h                           System definitions          
*       pcdisk.h                            File common definitions     
*                                                                       
*************************************************************************/

#include        "plus\nucleus.h"
#include        "file\pcdisk.h"
#if (RAMDISK)
#if (!RAMDISK_FROMPOOL)
#include        <malloc.h>
#endif
#endif

/*  The following table maintains a mapping between Nucleus PLUS pointers
    and Task IDs.  */
NU_TASK         *NUFP_TASK_POINTER[NUM_USERS];

/*  The following declarations are used for intialization of the Nucleus
    PLUS tasking environment for the Nucleus FILE system.  */


/************************************************************************
*  FUNCTION                                                             
*                                                                       
*       NUFP_Current_Task_ID                                            
*                                                                       
*  DESCRIPTION                                                          
*                                                                       
*       This function convert a Task Pointer to a Task ID.              
*                                                                       
*                                                                       
*  AUTHOR                                                               
*                                                                       
*       Neil F. Henderson, Accelerated Technology, Inc.                 
*                                                                       
*  INPUTS                                                               
*                                                                       
*       None.                                                           
*                                                                       
*  OUTPUTS                                                              
*                                                                       
*       task_id                             The id of the task that     
*                                           represents the task pointer.
*                                                                       
*************************************************************************/
INT NUFP_Current_Task_ID(VOID)
{
NU_TASK     *current_task_ptr;
INT         task_id;


    /*  Intialize the task_id. */
    task_id = 0;

    /*  Get the Task Pointer to the current task. */
    current_task_ptr = NU_Current_Task_Pointer();

    /*  Search for the Task Pointer.  */
    for (task_id = 0; task_id < NUM_USERS; task_id++)
    {
        /*  If we found the entry, then return the ID.  */
        if (NUFP_TASK_POINTER[task_id] == current_task_ptr)
            return(task_id);
    }

    /*  There is not one already established, so find a blank spot,
        set up the pointer, and return the ID. */
    for (task_id = 0; task_id < NUM_USERS; task_id++)
    {
        /*  If we found a blank entry, then return the ID.  */
        if (NUFP_TASK_POINTER[task_id] == NU_NULL)
        {
            /*  Save the entry so that we find it next time.  */
            NUFP_TASK_POINTER[task_id] = current_task_ptr;

            /*  Return the associated ID.  */
            return(task_id);
        }
    }

    /*  We did not find an empty entry for a new task.  That means that the
        user did a no no.  We need to invoke some kind of error handler here. */
    return(-1);

}   /*  end of NUFP_Current_Task_ID.  */


/************************************************************************
*  FUNCTION                                                             
*                                                                       
*       NUFP_Remove_User                                                
*                                                                       
*  DESCRIPTION                                                          
*                                                                       
*       This function is responsible from removing a user from the      
*       NUFP_TASK_POINTER table.                                        
*                                                                       
*  AUTHOR                                                               
*                                                                       
*       Neil F. Henderson, Accelerated Technology, Inc.                 
*                                                                       
*  INPUTS                                                               
*                                                                       
*       task_id                             Converted task ID from PLUS 
*                                            task pointer               
*                                                                       
*  OUTPUTS                                                              
*                                                                       
*       NUFP_TASK_POINTER                   Updated to remove the task  
*                                            pointed to by the ID.      
*                                                                       
*************************************************************************/
VOID NUFP_Remove_User(INT task_id)
{

    /*  Remove the task pointer.  */
    NUFP_TASK_POINTER[task_id] = NU_NULL;

}