pif.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

UNSIGNED         pointers;                  /* Number of pointers in list*/


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

    /* Initialize the number of pointers returned.  */
    pointers =  0;
    
    /* Protect against access to the list of created pipes.  */
    TCT_Protect(&PID_List_Protect);

    /* Loop until all pipe pointers are in the list or until the maximum 
       list size is reached.  */
    node_ptr =  PID_Created_Pipes_List;
    while ((node_ptr) && (pointers < maximum_pointers))
    {
    
        /* Place the node into the destination list.  */
        *pointer_list++ =  (NU_PIPE *) node_ptr;
        
        /* Increment the pointers variable.  */
        pointers++;

        /* Position the node pointer to the next node.  */
        node_ptr =  node_ptr -> cs_next;
        
        /* Determine if the pointer is at the head of the list.  */
        if (node_ptr == PID_Created_Pipes_List)
        
            /* The list search is complete.  */
            node_ptr =  NU_NULL;
    } 
                
    /* Release protection against access to the list of created pipes.  */
    TCT_Unprotect();

    /* Return the number of pointers in the list.  */
    return(pointers);
}


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      PIF_Pipe_Information                                             */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function returns information about the specified pipe.      */
/*      However, if the supplied pipe pointer is invalid, the            */
/*      function simply returns an error status.                         */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      William E. Lamie, Accelerated Technology, Inc.                   */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      [TCT_Check_Stack]                   Stack checking function      */
/*      TCT_System_Protect                  Protect pipe                 */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pipe_ptr                            Pointer to the pipe          */
/*      name                                Destination for the name     */
/*      start_address                       Destination for the start    */
/*                                            address of the pipe        */
/*      pipe_size                           Destination for pipe size    */
/*      available                           Destination for available    */
/*                                            room in pipe               */
/*      messages                            Destination for number of    */
/*                                            messages piped             */
/*      message_type                        Destination for message type */
/*      message_size                        Destination for message size */
/*      suspend_type                        Destination for suspension   */
/*                                            type                       */
/*      tasks_waiting                       Destination for the tasks    */
/*                                            waiting count              */
/*      first_task                          Destination for the pointer  */
/*                                            to the first task waiting  */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      NU_SUCCESS                          If a valid pipe pointer      */
/*                                            is supplied                */
/*      NU_INVALID_PIPE                     If pipe pointer invalid      */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*      W. Lamie        03-01-1993      Created initial version 1.0      */
/*      D. Lamie        04-19-1993      Verified version 1.0             */
/*      W. Lamie        03-01-1994      Modified function interface,     */
/*                                        resulting in version 1.1       */
/*      R. Pfaff -                                                       */
/*      D. Lamie        03-18-1994      Verified version 1.1             */
/*      M. Trippi       11-18-1996      Corrected SPR220.                */
/*                                                                       */
/*************************************************************************/
STATUS  PIF_Pipe_Information(NU_PIPE *pipe_ptr, CHAR *name, 
                  VOID **start_address, UNSIGNED *pipe_size, 
                  UNSIGNED *available, UNSIGNED *messages, 
                  OPTION *message_type, UNSIGNED *message_size,
                  OPTION *suspend_type, UNSIGNED *tasks_waiting,
                  NU_TASK **first_task)
{

PI_PCB         *pipe;                       /* Pipe control block ptr    */
INT             i;                          /* Working integer variable  */
STATUS          completion;                 /* Completion status         */



    /* Move input pipe pointer into internal pointer.  */
    pipe =  (PI_PCB *) pipe_ptr;


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

    /* Determine if this pipe id is valid.  */
    if ((pipe != NU_NULL) && (pipe -> pi_id == PI_PIPE_ID))
    {
    
        /* Setup protection of the pipe.  */
        TCT_System_Protect();

        /* The pipe pointer is valid.  Reflect this in the completion
           status and fill in the actual information.  */
        completion =  NU_SUCCESS;
        
        /* Copy the pipe's name.  */
        for (i = 0; i < NU_MAX_NAME; i++)
            *name++ =  pipe -> pi_name[i];

        /* Determine the suspension type.  */
        if (pipe -> pi_fifo_suspend)
            *suspend_type =  NU_FIFO;
        else
            *suspend_type =  NU_PRIORITY;
            
        /* Determine the message type.  */
        if (pipe -> pi_fixed_size)
            *message_type =  NU_FIXED_SIZE;
        else
            *message_type =  NU_VARIABLE_SIZE; 

        /* Get various information about the pipe.  */
        *start_address =  (VOID *) pipe -> pi_start;
        *pipe_size =      pipe -> pi_pipe_size;
        *available =      pipe -> pi_available;
        *messages =       pipe -> pi_messages;
        *message_size =   pipe -> pi_message_size;
        
        /* Retrieve the number of tasks waiting and the pointer to the 
           first task waiting.  */
        *tasks_waiting =  pipe -> pi_tasks_waiting;
        if (pipe -> pi_suspension_list)
    
            /* There is a task waiting.  */
            *first_task =  (NU_TASK *)
                (pipe -> pi_suspension_list) -> pi_suspended_task;
        else
        
            /* There are no tasks waiting.  */
            *first_task =  NU_NULL;
    
        /* Release protection of the pipe.  */
        TCT_Unprotect();
    }
    else
    
        /* Indicate that the pipe pointer is invalid.   */
        completion =  NU_INVALID_PIPE;

    /* Return the appropriate completion status.  */
    return(completion);
}