pis.c

test file nucleus source

/*************************************************************************/
/*                                                                       */
/*               Copyright Mentor Graphics Corporation 2002              */
/*                         All Rights Reserved.                          */
/*                                                                       */
/* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS  */
/* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS   */
/* SUBJECT TO LICENSE TERMS.                                             */
/*                                                                       */
/*************************************************************************/

/*************************************************************************/
/*                                                                       */
/* FILE NAME                                               VERSION       */
/*                                                                       */
/*      pis.c                                          Nucleus PLUS 1.14 */
/*                                                                       */
/* COMPONENT                                                             */
/*                                                                       */
/*      PI - Pipe Management                                             */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This file contains the supplemental routines for the pipe        */
/*      management component.                                            */
/*                                                                       */
/* DATA STRUCTURES                                                       */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* FUNCTIONS                                                             */
/*                                                                       */
/*      PIS_Reset_Pipe                      Reset a pipe                 */
/*      PIS_Send_To_Front_Of_Pipe           Send message to pipe's front */
/*      PIS_Broadcast_To_Pipe               Broadcast a message to pipe  */
/*                                                                       */
/* DEPENDENCIES                                                          */
/*                                                                       */
/*      cs_extr.h                           Common Service functions     */
/*      tc_extr.h                           Thread Control functions     */
/*      pi_extr.h                           Pipe functions               */
/*      hi_extr.h                           History functions            */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         DATE                    REMARKS                               */
/*                                                                       */
/*      03-01-1994      Created initial version 1.1 from                 */
/*                      routines originally in core                      */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*      04-17-1996      updated to version 1.2                           */
/*      02-04-1998      Corrected SPR434 resulting in                    */
/*                      version 1.2a.                                    */
/*      03-24-1998      Released version 1.3                             */
/*      03-26-1999      Released 1.11m (new release                      */
/*                        numbering scheme)                              */
/*      04-17-2002      Released version 1.13m                           */
/*      11-07-2002      Released version 1.14                            */
/*************************************************************************/
#define         NU_SOURCE_FILE


#include        "cs_extr.h"                 /* Common service functions  */
#include        "tc_extr.h"                 /* Thread control functions  */
#include        "pi_extr.h"                 /* Pipe functions            */
#include        "hi_extr.h"                 /* History functions         */
#include        "profiler.h"                /* ProView interface         */


/* Define external inner-component global data references.  */

extern CS_NODE         *PID_Created_Pipes_List;
extern UNSIGNED         PID_Total_Pipes;
extern TC_PROTECT       PID_List_Protect;


/* Define internal component function prototypes.  */

VOID    PIC_Cleanup(VOID *information);


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      PIS_Reset_Pipe                                                   */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function resets the specified pipe back to the original     */
/*      state.  Any messages in the pipe are discarded.  Also, any       */
/*      tasks currently suspended on the pipe are resumed with the       */
/*      reset status.                                                    */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      PISE_Reset_Pipe                     Error checking shell         */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      [HIC_Make_History_Entry]            Make entry in history log    */
/*      TCC_Resume_Task                     Resume a suspended task      */
/*      [TCT_Check_Stack]                   Stack checking function      */
/*      TCT_Control_To_System               Transfer control to system   */
/*      TCT_System_Protect                  Protect against system access*/
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pipe_ptr                            Pipe control block pointer   */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      NU_SUCCESS                                                       */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*      03-01-1993      Created initial version 1.0                      */
/*      04-19-1993      Verified version 1.0                             */
/*      03-01-1994      Changed function interfaces to                   */
/*                      match those in prototype,                        */
/*                      added register options, changed                  */
/*                      protection logic to reduce                       */
/*                      overhead, fixed read and write                   */
/*                      pointers to both point at the                    */
/*                      start, resulting in version 1.1                  */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*      02-04-1998      Corrected SPR434.                                */
/*                                                                       */
/*************************************************************************/
STATUS  PIS_Reset_Pipe(NU_PIPE *pipe_ptr)
{

R1 PI_PCB      *pipe;                       /* Pipe control block ptr    */
PI_SUSPEND     *suspend_ptr;                /* Suspend block pointer     */
PI_SUSPEND     *next_ptr;                   /* Next suspend block pointer*/
STATUS          preempt;                    /* Status for resume call    */
NU_SUPERV_USER_VARIABLES

    /* Switch to supervisor mode */
    NU_SUPERVISOR_MODE();

    /* 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

#ifdef  NU_ENABLE_HISTORY

    /* Make an entry that corresponds to this function in the system history
       log.  */
    HIC_Make_History_Entry(NU_RESET_PIPE_ID, (UNSIGNED) pipe,
                                        (UNSIGNED) 0, (UNSIGNED) 0);

#endif

    /* Protect against access to the pipe.  */
    TCT_System_Protect();

    /* Pickup the suspended task suspension list.  */
    suspend_ptr =  pipe -> pi_suspension_list;

    /* Walk the chain task(s) currently suspended on the pipe.  */
    preempt =  0;
    while (suspend_ptr)
    {

        /* Resume the suspended task.  Insure that the status returned is
           NU_PIPE_RESET.  */
        suspend_ptr -> pi_return_status =  NU_PIPE_RESET;

        /* Point to the next suspend structure in the link.  */
        next_ptr =  (PI_SUSPEND *) (suspend_ptr -> pi_suspend_link.cs_next);

        /* Resume the specified task.  */
        preempt =  preempt |
            TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
                                                NU_PIPE_SUSPEND);

        /* Determine if the next is the same as the head pointer.  */
        if (next_ptr == pipe -> pi_suspension_list)

            /* Clear the suspension pointer to signal the end of the list
               traversal.  */
            suspend_ptr =  NU_NULL;
        else

            /* Position the suspend pointer to the next block.  */
            suspend_ptr =  next_ptr;
    }

    /* Pickup the urgent message suspension list.  */
    suspend_ptr =  pipe -> pi_urgent_list;

    /* Walk the chain task(s) currently suspended on the pipe.  */
    while (suspend_ptr)
    {

        /* Resume the suspended task.  Insure that the status returned is
           NU_PIPE_RESET.  */
        suspend_ptr -> pi_return_status =  NU_PIPE_RESET;

        /* Point to the next suspend structure in the link.  */
        next_ptr =  (PI_SUSPEND *) (suspend_ptr -> pi_suspend_link.cs_next);

        /* Resume the specified task.  */
        preempt =  preempt |
            TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
                                                NU_PIPE_SUSPEND);

        /* Determine if the next is the same as the head pointer.  */
        if (next_ptr == pipe -> pi_urgent_list)

            /* Clear the suspension pointer to signal the end of the list
               traversal.  */
            suspend_ptr =  NU_NULL;
        else

            /* Position the suspend pointer to the next active block.  */
            suspend_ptr =  next_ptr;
    }

    /* Initialize various elements of the pipe.  */
    pipe -> pi_available =             pipe -> pi_end - pipe -> pi_start;
    pipe -> pi_messages =              0;
    pipe -> pi_read =                  pipe -> pi_start;
    pipe -> pi_write =                 pipe -> pi_start;
    pipe -> pi_tasks_waiting =         0;
    pipe -> pi_suspension_list =       NU_NULL;
    pipe -> pi_urgent_list =           NU_NULL;

#ifdef INCLUDE_PROVIEW
    _RTProf_DumpPipe(RT_PROF_RESET_PIPE,pipe,RT_PROF_OK);
#endif /* INCLUDE_PROVIEW */

    /* Determine if preemption needs to occur.  */
    if (preempt)

        /* Transfer control to system to facilitate preemption.  */
        TCT_Control_To_System();

    /* Release protection against access to the pipe.  */
    TCT_Unprotect();

    /* Return to user mode */
    NU_USER_MODE();

    /* Return a successful completion.  */
    return(NU_SUCCESS);
}


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      PIS_Send_To_Front_Of_Pipe                                        */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function sends a message to the front of the specified      */
/*      message pipe.  The message length is determined by the caller.   */
/*      If there are any tasks suspended on the pipe for a message, the  */
/*      message is copied into the message area of the first waiting     */
/*      task and that task is resumed.  If there is enough room in the   */
/*      pipe, the message is copied in front of all other messages.      */
/*      If there is not enough room in the pipe, suspension of the       */
/*      caller is possible.                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */