mbs.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       */
/*                                                                       */
/*      mbs.c                                          Nucleus PLUS 1.14 */
/*                                                                       */
/* COMPONENT                                                             */
/*                                                                       */
/*      MB - Mailbox Management                                          */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This file contains the core routines for the Mailbox management  */
/*      component.                                                       */
/*                                                                       */
/* DATA STRUCTURES                                                       */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* FUNCTIONS                                                             */
/*                                                                       */
/*      MBS_Reset_Mailbox                   Reset a mailbox              */
/*      MBS_Broadcast_To_Mailbox            Broadcast a mailbox message  */
/*                                                                       */
/* DEPENDENCIES                                                          */
/*                                                                       */
/*      cs_extr.h                           Common Service functions     */
/*      tc_extr.h                           Thread Control functions     */
/*      mb_extr.h                           Mailbox functions            */
/*      hi_extr.h                           History functions            */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*        DATE                    REMARKS                                */
/*                                                                       */
/*      03-01-1994      Initial version of supplemental                  */
/*                      mailbox service file,                            */
/*                      version 1.1                                      */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*      04-17-1996      updated to version 1.2                           */
/*      03-24-1998      Released version 1.3                             */
/*      03-26-1999      Released 1.11m (new release                      */
/*                        numbering scheme)                              */
/*      04-23-2001      Fixed problem with resuming task in              */
/*                        MBS_Broadcast_To_Mailbox                       */
/*      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        "mb_extr.h"                 /* Mailbox functions         */
#include        "hi_extr.h"                 /* History functions         */
#include        "profiler.h"                /* ProView interface         */


/* Define internal component function prototypes.  */

VOID    MBC_Cleanup(VOID *information);


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      MBS_Reset_Mailbox                                                */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function resets a mailbox back to the initial state.  Any   */
/*      message in the mailbox is discarded.  Also, all tasks suspended  */
/*      on the mailbox are resumed with the reset completion status.     */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      MBSE_Reset_Mailbox                  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 mailbox              */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      mailbox_ptr                         Mailbox 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 interface to                    */
/*                      match the prototype, added                       */
/*                      register variable logic,                         */
/*                      optimized protection logic,                      */
/*                      resulting in version 1.1                         */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*                                                                       */
/*************************************************************************/
STATUS  MBS_Reset_Mailbox(NU_MAILBOX *mailbox_ptr)
{

R1 MB_MCB      *mailbox;                    /* Mailbox control block ptr */
R2 MB_SUSPEND  *suspend_ptr;                /* Suspend block pointer     */
MB_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 mailbox pointer into internal pointer.  */
    mailbox =  (MB_MCB *) mailbox_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_MAILBOX_ID, (UNSIGNED) mailbox,
                                        (UNSIGNED) 0, (UNSIGNED) 0);

#endif

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

    /* Pickup the suspended task pointer list.  */
    suspend_ptr =  mailbox -> mb_suspension_list;

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

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

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

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

        /* Determine if the next is the same as the head pointer.  */
        if (next_ptr == mailbox -> mb_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 suspend block.  */
            suspend_ptr =  next_ptr;
    }

    /* Initialize the mailbox.  */
    mailbox -> mb_message_present =  NU_FALSE;
    mailbox -> mb_tasks_waiting =    0;
    mailbox -> mb_suspension_list =  NU_NULL;

#ifdef INCLUDE_PROVIEW
    _RTProf_DumpMailBox(RT_PROF_RESET_MAILBOX,mailbox,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.  */
    TCT_Unprotect();

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

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


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      MBS_Broadcast_To_Mailbox                                         */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function sends a message to all tasks currently waiting for */
/*      a message from the mailbox.  If no tasks are waiting, this       */
/*      service behaves like a normal send message.                      */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      MBSE_Broadcast_To_Mailbox           Broadcast to a mailbox       */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      CSC_Place_On_List                   Place on suspend list        */
/*      CSC_Priority_Place_On_List          Place on priority list       */
/*      CSC_Remove_From_List                Remove from suspend list     */
/*      [HIC_Make_History_Entry]            Make entry in history log    */
/*      TCC_Resume_Task                     Resume a suspended task      */
/*      TCC_Suspend_Task                    Suspend calling task         */
/*      TCC_Task_Priority                   Priority of specified task   */
/*      [TCT_Check_Stack]                   Stack checking function      */
/*      TCT_Control_To_System               Transfer control to system   */
/*      TCT_Current_Thread                  Pickup current thread pointer*/
/*      TCT_System_Protect                  Protect mailbox              */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */