+
−/*************************************************************************/
+
−/*                                                                       */
+
−/*               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       */
+
−/*                                                                       */
+
−/*      mbc.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                                                             */
+
−/*                                                                       */
+
−/*      MBC_Create_Mailbox                  Create a mailbox             */
+
−/*      MBC_Delete_Mailbox                  Delete a mailbox             */
+
−/*      MBC_Send_To_Mailbox                 Send a mailbox message       */
+
−/*      MBC_Receive_From_Mailbox            Receive a mailbox message    */
+
−/*      MBC_Cleanup                         Cleanup on timeout or a      */
+
−/*                                          terminate condition          */
+
−/*                                                                       */
+
−/* 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                               */
+
−/*                                                                       */
+
−/*      03-01-1993      Created initial version 1.0                      */
+
−/*      04-19-1993      Verified version 1.0                             */
+
−/*      08-09-1993      Corrected pointer retrieval                      */
+
−/*                      loop, resulting in version 1.0a                  */
+
−/*      08-09-1993      Verified version 1.0a                            */
+
−/*      03-01-1994      Moved non-core functions into                    */
+
−/*                      supplemental files, changed                      */
+
−/*                      function interfaces to match                     */
+
−/*                      those in prototype, added                        */
+
−/*                      register options, changed                        */
+
−/*                      protection logic to reduce                       */
+
−/*                      overhead, resulting in                           */
+
−/*                      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)                              */
+
−/*      04-17-2002      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 external inner-component global data references.  */
+
−
+
−extern CS_NODE         *MBD_Created_Mailboxes_List;
+
−extern UNSIGNED         MBD_Total_Mailboxes;
+
−extern TC_PROTECT       MBD_List_Protect;
+
−
+
−
+
−/* Define internal component function prototypes.  */
+
−
+
−VOID    MBC_Cleanup(VOID *information);
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      MBC_Create_Mailbox                                               */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function creates a mailbox and then places it on the list   */
+
−/*      of created mailboxes.                                            */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      MBCE_Create_Mailbox                 Error checking shell         */
+
−/*                                                                       */
+
−/* CALLS                                                                 */
+
−/*                                                                       */
+
−/*      CSC_Place_On_List                   Add node to linked-list      */
+
−/*      [HIC_Make_History_Entry]            Make entry in history log    */
+
−/*      [TCT_Check_Stack]                   Stack checking function      */
+
−/*      TCT_Protect                         Data structure protect       */
+
−/*      TCT_Unprotect                       Un-protect data structure    */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      mailbox_ptr                         Mailbox control block pointer*/
+
−/*      name                                Mailbox name                 */
+
−/*      suspend_type                        Suspension type              */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                                                       */
+
−/*                                                                       */
+
−/* HISTORY                                                               */
+
−/*                                                                       */
+
−/*        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,                         */
+
−/*                      resulting in version 1.1                         */
+
−/*                                                                       */
+
−/*      03-18-1994      Verified version 1.1                             */
+
−/*                                                                       */
+
−/*************************************************************************/
+
−STATUS  MBC_Create_Mailbox(NU_MAILBOX *mailbox_ptr, CHAR *name,
+
−                                                OPTION suspend_type)
+
−{
+
−
+
−R1 MB_MCB      *mailbox;                    /* Mailbox control block ptr */
+
−INT             i;                          /* Working index variable    */
+
−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_CREATE_MAILBOX_ID, (UNSIGNED) mailbox,
+
−                                (UNSIGNED) name, (UNSIGNED) suspend_type);
+
−
+
−#endif
+
−
+
−    /* First, clear the mailbox ID just in case it is an old Mailbox
+
−       Control Block.  */
+
−    mailbox -> mb_id =             0;
+
−
+
−    /* Fill in the mailbox name.  */
+
−    for (i = 0; i < NU_MAX_NAME; i++)
+
−        mailbox -> mb_name[i] =  name[i];
+
−
+
−    /* Clear the message present flag- initial it to "no message present." */
+
−    mailbox -> mb_message_present =  NU_FALSE;
+
−
+
−    /* Setup the mailbox suspension type.  */
+
−    if (suspend_type == NU_FIFO)
+
−
+
−        /* FIFO suspension is selected, setup the flag accordingly.  */
+
−        mailbox -> mb_fifo_suspend =  NU_TRUE;
+
−    else
+
−
+
−        /* Priority suspension is selected.  */
+
−        mailbox -> mb_fifo_suspend =  NU_FALSE;
+
−
+
−    /* Clear the suspension list pointer.  */
+
−    mailbox -> mb_suspension_list =  NU_NULL;
+
−
+
−    /* Clear the number of tasks waiting on the mailbox counter.  */
+
−    mailbox -> mb_tasks_waiting =  0;
+
−
+
−    /* Initialize link pointers.  */
+
−    mailbox -> mb_created.cs_previous =    NU_NULL;
+
−    mailbox -> mb_created.cs_next =        NU_NULL;
+
−
+
−    /* Protect against access to the list of created mailboxes.  */
+
−    TCT_Protect(&MBD_List_Protect);
+
−
+
−    /* At this point the mailbox is completely built.  The ID can now be
+
−       set and it can be linked into the created mailbox list.  */
+
−    mailbox -> mb_id =                     MB_MAILBOX_ID;
+
−
+
−    /* Link the mailbox into the list of created mailboxes and increment the
+
−       total number of mailboxes in the system.  */
+
−    CSC_Place_On_List(&MBD_Created_Mailboxes_List, &(mailbox -> mb_created));
+
−    MBD_Total_Mailboxes++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−    _RTProf_DumpMailBox(RT_PROF_CREATE_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−    /* Release protection against access to the list of created mailboxes.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return successful completion.  */
+
−    return(NU_SUCCESS);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      MBC_Delete_Mailbox                                               */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function deletes a mailbox and removes it from the list of  */
+
−/*      created mailboxes.  All tasks suspended on the mailbox are       */
+
−/*      resumed.  Note that this function does not free the memory       */
+
−/*      associated with the mailbox control block.                       */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      MBCE_Delete_Mailbox                 Error checking shell         */
+
−/*                                                                       */
+
−/* CALLS                                                                 */
+
−/*                                                                       */
+
−/*      CSC_Remove_From_List                Remove node from list        */
+
−/*      [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_Protect                         Protect created list         */
+
−/*      TCT_Set_Current_Protect             Setup current protection ptr */
+
−/*      TCT_System_Protect                  Protect against system access*/
+
−/*      TCT_System_Unprotect                Release system protection    */
+
−/*      TCT_Unprotect                       Release protection           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      mailbox_ptr                         Mailbox control block pointer*/
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                                                       */
+
−/*                                                                       */
+
−/* HISTORY                                                               */
+
−/*                                                                       */
+
−/*         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  MBC_Delete_Mailbox(NU_MAILBOX *mailbox_ptr)
+
−{
+
−
+
−R1 MB_MCB      *mailbox;                    /* Mailbox control block ptr */
+
−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_DELETE_MAILBOX_ID, (UNSIGNED) mailbox,
+
−                                        (UNSIGNED) 0, (UNSIGNED) 0);
+
−
+
−#endif
+
−
+
−    /* Call protection just in case another thread is using the mailbox.  */
+
−    TCT_System_Protect();
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−    _RTProf_DumpMailBox(RT_PROF_DELETE_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−    /* Clear the mailbox ID.  */
+
−    mailbox -> mb_id =  0;
+
−
+
−    /* Clear protection.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Protect against access to the list of created mailboxes.  */
+
−    TCT_Protect(&MBD_List_Protect);
+
−
+
−    /* Remove the mailbox from the list of created mailboxes.  */
+
−    CSC_Remove_From_List(&MBD_Created_Mailboxes_List,
+
−                                        &(mailbox -> mb_created));
+
−
+
−    /* Decrement the total number of created mailboxes.  */
+
−    MBD_Total_Mailboxes--;
+
−
+
−    /* 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)
+
−    {
+
−
+
−        /* Protect against system access.  */
+
−        TCT_System_Protect();
+
−
+
−        /* Resume the suspended task.  Insure that the status returned is
+
−           NU_MAILBOX_DELETED.  */
+
−        suspend_ptr -> mb_return_status =  NU_MAILBOX_DELETED;
+
−
+
−        /* 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;
+
−
+
−            /* Setup current protection pointer.  */
+
−        TCT_Set_Current_Protect(&MBD_List_Protect);
+
−
+
−        /* Unprotect the system protection.  */
+
−        TCT_System_Unprotect();
+
−    }
+
−
+
−    /* 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 list of created mailboxes.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return a successful completion.  */
+
−    return(NU_SUCCESS);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      MBC_Send_To_Mailbox                                              */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function sends a 4-word message to the specified mailbox.   */
+
−/*      If there are one or more tasks suspended on the mailbox for a    */
+
−/*      message, the message is copied into the message area of the      */
+
−/*      first task waiting and that task is resumed.  If the mailbox     */
+
−/*      is full, suspension of the calling task is possible.             */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      MBCE_Send_To_Mailbox                Error checking shell         */
+
−/*                                                                       */
+
−/* 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                   Pickup task's priority       */
+
−/*      [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 against system access*/
+
−/*      TCT_Unprotect                       Release protection           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      mailbox_ptr                         Mailbox control block pointer*/
+
−/*      message                             Pointer to message to send   */
+
−/*      suspend                             Suspension option if full    */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                          If service is successful     */
+
−/*      NU_MAILBOX_FULL                     If mailbox is currently full */
+
−/*      NU_TIMEOUT                          If timeout on service expires*/
+
−/*      NU_MAILBOX_DELETED                  If mailbox is deleted during */
+
−/*                                            suspension                 */
+
−/*      NU_MAILBOX_RESET                    If mailbox is deleted during */
+
−/*                                            suspension                 */
+
−/*                                                                       */
+
−/* HISTORY                                                               */
+
−/*                                                                       */
+
−/*         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  MBC_Send_To_Mailbox(NU_MAILBOX *mailbox_ptr, VOID *message,
+
−                                                        UNSIGNED suspend)
+
−{
+
−
+
−R1 MB_MCB      *mailbox;                    /* Mailbox control block ptr */
+
−MB_SUSPEND      suspend_block;              /* Allocate suspension block */
+
−R2 MB_SUSPEND  *suspend_ptr;                /* Pointer to suspend block  */
+
−R3 UNSIGNED    *source_ptr;                 /* Pointer to source         */
+
−R4 UNSIGNED    *destination_ptr;            /* Pointer to destination    */
+
−TC_TCB         *task;                       /* Task pointer              */
+
−STATUS          preempt;                    /* Preempt flag              */
+
−STATUS          status;                     /* Completion status         */
+
−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_SEND_TO_MAILBOX_ID, (UNSIGNED) mailbox,
+
−                                       (UNSIGNED) message, (UNSIGNED) suspend);
+
−
+
−#endif
+
−
+
−    /* Initialize the status as successful.  */
+
−    status =  NU_SUCCESS;
+
−
+
−    /* Protect against simultaneous access to the mailbox.  */
+
−    TCT_System_Protect();
+
−
+
−    /* Determine if the mailbox is empty or full.  */
+
−    if (mailbox -> mb_message_present)
+
−    {
+
−
+
−        /* Mailbox already has a message.  Determine if suspension is
+
−           required.  */
+
−        if (suspend)
+
−        {
+
−
+
−            /* Suspension is requested.   */
+
−
+
−            /* Increment the number of tasks waiting.  */
+
−            mailbox -> mb_tasks_waiting++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−    _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_WAIT);
+
−#endif /* INCLUDE_PROVIEW */
+
−
+
−            /* Setup the suspend block and suspend the calling task.  */
+
−            suspend_ptr =  &suspend_block;
+
−            suspend_ptr -> mb_mailbox =                  mailbox;
+
−            suspend_ptr -> mb_suspend_link.cs_next =     NU_NULL;
+
−            suspend_ptr -> mb_suspend_link.cs_previous = NU_NULL;
+
−            suspend_ptr -> mb_message_area =             (UNSIGNED *) message;
+
−            task =                           (TC_TCB *)  TCT_Current_Thread();
+
−            suspend_ptr -> mb_suspended_task =           task;
+
−
+
−            /* Determine if priority or FIFO suspension is associated with the
+
−               mailbox.  */
+
−            if (mailbox -> mb_fifo_suspend)
+
−            {
+
−
+
−                /* FIFO suspension is required.  Link the suspend block into
+
−                   the list of suspended tasks on this mailbox.  */
+
−                CSC_Place_On_List((CS_NODE **) &(mailbox ->mb_suspension_list),
+
−                                        &(suspend_ptr -> mb_suspend_link));
+
−            }
+
−            else
+
−            {
+
−
+
−                /* Get the priority of the current thread so the suspend block
+
−                   can be placed in the appropriate place.  */
+
−                suspend_ptr -> mb_suspend_link.cs_priority =
+
−                                                     TCC_Task_Priority(task);
+
−
+
−                CSC_Priority_Place_On_List((CS_NODE **)
+
−                        &(mailbox -> mb_suspension_list),
+
−                                        &(suspend_ptr -> mb_suspend_link));
+
−            }
+
−
+
−            /* Finally, suspend the calling task. Note that the suspension call
+
−               automatically clears the protection on the mailbox.  */
+
−            TCC_Suspend_Task((NU_TASK *) task, NU_MAILBOX_SUSPEND,
+
−                                MBC_Cleanup, suspend_ptr, suspend);
+
−
+
−            /* Pickup the return status.  */
+
−            status =  suspend_ptr -> mb_return_status;
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Return a status of NU_MAILBOX_FULL because there is no
+
−               room in the mailbox for the message.  */
+
−            status =  NU_MAILBOX_FULL;
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_FAIL);
+
−#endif /* INCLUDE_PROVIEW */
+
−
+
−        }
+
−    }
+
−    else
+
−    {
+
−
+
−        /* Determine if a task is waiting on the mailbox.  */
+
−        if (mailbox -> mb_suspension_list)
+
−        {
+
−
+
−            /* Task is waiting on mailbox for a message.  */
+
−
+
−            /* Decrement the number of tasks waiting on mailbox.  */
+
−            mailbox -> mb_tasks_waiting--;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−
+
−            /* Remove the first suspended block from the list.  */
+
−            suspend_ptr =  mailbox -> mb_suspension_list;
+
−            CSC_Remove_From_List((CS_NODE **)
+
−                &(mailbox -> mb_suspension_list),
+
−                                &(suspend_ptr -> mb_suspend_link));
+
−
+
−            /* Setup the source and destination pointers.  */
+
−            source_ptr =       (UNSIGNED *) message;
+
−            destination_ptr =  suspend_ptr -> mb_message_area;
+
−
+
−            /* Copy the message directly into the waiting task's
+
−               destination.  */
+
−            *destination_ptr       =  *source_ptr;
+
−            *(destination_ptr + 1) =  *(source_ptr + 1);
+
−            *(destination_ptr + 2) =  *(source_ptr + 2);
+
−            *(destination_ptr + 3) =  *(source_ptr + 3);
+
−
+
−            /* Setup the appropriate return value.  */
+
−            suspend_ptr -> mb_return_status =  NU_SUCCESS;
+
−
+
−            /* Wakeup the waiting task and check for preemption.  */
+
−            preempt =
+
−               TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task,
+
−                                                NU_MAILBOX_SUSPEND);
+
−
+
−            /* Determine if preemption needs to take place. */
+
−            if (preempt)
+
−
+
−                 /* Transfer control to the system if the resumed task function
+
−                   detects a preemption condition.  */
+
−                TCT_Control_To_System();
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Mailbox is empty and no task is waiting.  */
+
−
+
−            /* Setup the source and destination pointers.  */
+
−            source_ptr =       (UNSIGNED *) message;
+
−            destination_ptr =  &(mailbox -> mb_message_area[0]);
+
−
+
−            /* Place the message in the mailbox. */
+
−            *destination_ptr =        *source_ptr;
+
−            *(destination_ptr + 1) =  *(source_ptr + 1);
+
−            *(destination_ptr + 2) =  *(source_ptr + 2);
+
−            *(destination_ptr + 3) =  *(source_ptr + 3);
+
−
+
−            /* Indicate that the mailbox has a message.  */
+
−            mailbox -> mb_message_present =  NU_TRUE;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−        }
+
−    }
+
−
+
−    /* Release protection.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return the completion status.  */
+
−    return(status);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      MBC_Receive_From_Mailbox                                         */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function receives a message from the specified mailbox.     */
+
−/*      If there is a message currently in the mailbox, the message is   */
+
−/*      removed from the mailbox and placed in the caller's area.        */
+
−/*      Otherwise, if no message is present in the mailbox, suspension   */
+
−/*      of the calling task is possible.                                 */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      MBCE_Receive_From_Mailbox           Error checking shell         */
+
−/*                                                                       */
+
−/* 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                   Pickup task priority         */
+
−/*      [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           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      mailbox_ptr                         Mailbox control block pointer*/
+
−/*      message                             Pointer to message to send   */
+
−/*      suspend                             Suspension option if empty   */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                          If service is successful     */
+
−/*      NU_MAILBOX_EMPTY                    If mailbox is currently empty*/
+
−/*      NU_TIMEOUT                          If timeout on service expires*/
+
−/*      NU_MAILBOX_DELETED                  If mailbox is deleted during */
+
−/*                                            suspension                 */
+
−/*      NU_MAILBOX_RESET                    If mailbox is deleted during */
+
−/*                                            suspension                 */
+
−/*                                                                       */
+
−/* HISTORY                                                               */
+
−/*                                                                       */
+
−/*         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  MBC_Receive_From_Mailbox(NU_MAILBOX *mailbox_ptr, VOID *message,
+
−                                                        UNSIGNED suspend)
+
−{
+
−
+
−R1 MB_MCB      *mailbox;                    /* Mailbox control block ptr */
+
−MB_SUSPEND      suspend_block;              /* Allocate suspension block */
+
−R2 MB_SUSPEND  *suspend_ptr;                /* Pointer to suspend block  */
+
−R3 UNSIGNED    *source_ptr;                 /* Pointer to source         */
+
−R4 UNSIGNED    *destination_ptr;            /* Pointer to destination    */
+
−TC_TCB         *task;                       /* Task pointer              */
+
−STATUS          preempt;                    /* Preemption flag           */
+
−STATUS          status;                     /* Completion status         */
+
−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_RECEIVE_FROM_MAILBOX_ID, (UNSIGNED) mailbox,
+
−                                       (UNSIGNED) message, (UNSIGNED) suspend);
+
−
+
−#endif
+
−
+
−    /* Initialize the status as successful.  */
+
−    status =  NU_SUCCESS;
+
−
+
−    /* Protect against simultaneous access to the mailbox.  */
+
−    TCT_System_Protect();
+
−
+
−    /* Determine if the mailbox is empty or full.  */
+
−    if (mailbox -> mb_message_present)
+
−    {
+
−
+
−        /* Copy message from mailbox into the caller's area.  */
+
−
+
−        /* Setup the source and destination pointers.  */
+
−        source_ptr =       &(mailbox -> mb_message_area[0]);
+
−        destination_ptr =  (UNSIGNED *) message;
+
−
+
−        /* Copy the message directly into the waiting task's
+
−           destination.  */
+
−        *destination_ptr =        *source_ptr;
+
−        *(destination_ptr + 1) =  *(source_ptr + 1);
+
−        *(destination_ptr + 2) =  *(source_ptr + 2);
+
−        *(destination_ptr + 3) =  *(source_ptr + 3);
+
−
+
−        /* Determine if another task is waiting to place something into the
+
−           mailbox.  */
+
−        if (mailbox -> mb_suspension_list)
+
−        {
+
−
+
−            /* Yes, another task is waiting to send something to the
+
−               mailbox.  */
+
−
+
−            /* Decrement the number of tasks waiting counter.  */
+
−            mailbox -> mb_tasks_waiting--;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−            /* Remove the first suspended block from the list.  */
+
−            suspend_ptr =  mailbox -> mb_suspension_list;
+
−            CSC_Remove_From_List((CS_NODE **)
+
−                &(mailbox -> mb_suspension_list),
+
−                                &(suspend_ptr -> mb_suspend_link));
+
−
+
−            /* Setup the source and destination pointers.  */
+
−            source_ptr =       suspend_ptr -> mb_message_area;
+
−            destination_ptr =  &(mailbox -> mb_message_area[0]);
+
−
+
−            /* Copy the message directly into the waiting task's
+
−               destination.  */
+
−            *destination_ptr =        *source_ptr;
+
−            *(destination_ptr + 1) =  *(source_ptr + 1);
+
−            *(destination_ptr + 2) =  *(source_ptr + 2);
+
−            *(destination_ptr + 3) =  *(source_ptr + 3);
+
−
+
−            /* Setup the appropriate return value.  */
+
−            suspend_ptr -> mb_return_status =  NU_SUCCESS;
+
−
+
−            /* Resume the suspended task.  */
+
−            preempt =
+
−               TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task,
+
−                                                       NU_MAILBOX_SUSPEND);
+
−
+
−            /* Determine if a preempt condition is present.  */
+
−            if (preempt)
+
−
+
−                /* Transfer control to the system if the resumed task function
+
−                   detects a preemption condition.  */
+
−                TCT_Control_To_System();
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Clear the message present flag.  */
+
−            mailbox -> mb_message_present =  NU_FALSE;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_OK);
+
−#endif /* INCLUDE_PROVIEW */
+
−
+
−        }
+
−
+
−    }
+
−    else
+
−    {
+
−
+
−        /* Mailbox is empty.  Determine if suspension is required.  */
+
−        if (suspend)
+
−        {
+
−
+
−            /* Suspension is required.  */
+
−
+
−            /* Increment the number of tasks waiting on the mailbox counter. */
+
−            mailbox -> mb_tasks_waiting++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_WAIT);
+
−#endif /* INCLUDE_PROVIEW */
+
−
+
−            /* Setup the suspend block and suspend the calling task.  */
+
−            suspend_ptr =  &suspend_block;
+
−            suspend_ptr -> mb_mailbox =                  mailbox;
+
−            suspend_ptr -> mb_suspend_link.cs_next =     NU_NULL;
+
−            suspend_ptr -> mb_suspend_link.cs_previous = NU_NULL;
+
−            suspend_ptr -> mb_message_area =             (UNSIGNED *) message;
+
−            task =                            (TC_TCB *) TCT_Current_Thread();
+
−            suspend_ptr -> mb_suspended_task =           task;
+
−
+
−            /* Determine if priority or FIFO suspension is associated with the
+
−               mailbox.  */
+
−            if (mailbox -> mb_fifo_suspend)
+
−            {
+
−
+
−                /* FIFO suspension is required.  Link the suspend block into
+
−                   the list of suspended tasks on this mailbox.  */
+
−                CSC_Place_On_List((CS_NODE **) &(mailbox ->mb_suspension_list),
+
−                                        &(suspend_ptr -> mb_suspend_link));
+
−            }
+
−            else
+
−            {
+
−
+
−                /* Get the priority of the current thread so the suspend block
+
−                   can be placed in the appropriate place.  */
+
−                suspend_ptr -> mb_suspend_link.cs_priority =
+
−                                                       TCC_Task_Priority(task);
+
−
+
−                CSC_Priority_Place_On_List((CS_NODE **)
+
−                        &(mailbox -> mb_suspension_list),
+
−                                        &(suspend_block.mb_suspend_link));
+
−            }
+
−
+
−            /* Finally, suspend the calling task. Note that the suspension call
+
−               automatically clears the protection on the mailbox.  */
+
−            TCC_Suspend_Task((NU_TASK *) task, NU_MAILBOX_SUSPEND,
+
−                                        MBC_Cleanup, &suspend_block, suspend);
+
−
+
−            /* Pickup the return status.  */
+
−            status =  suspend_ptr -> mb_return_status;
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Return a status of NU_MAILBOX_EMPTY because there is
+
−               nothing in the mailbox.  */
+
−            status =  NU_MAILBOX_EMPTY;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_FAIL);
+
−#endif /* INCLUDE_PROVIEW */
+
−        }
+
−
+
−    }
+
−
+
−    /* Release protection.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return the completion status.  */
+
−    return(status);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      MBC_Cleanup                                                      */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function is responsible for removing a suspension block     */
+
−/*      from a mailbox.  It is not called unless a timeout or a task     */
+
−/*      terminate is in progress.  Note that protection is already in    */
+
−/*      effect - the same protection at suspension time.                 */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      TCC_Timeout                         Task timeout                 */
+
−/*      TCC_Terminate                       Task terminate               */
+
−/*                                                                       */
+
−/* CALLS                                                                 */
+
−/*                                                                       */
+
−/*      CSC_Remove_From_List                Remove suspend block from    */
+
−/*                                            the suspension list        */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      information                         Pointer to suspend block     */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      None                                                             */
+
−/*                                                                       */
+
−/* HISTORY                                                               */
+
−/*                                                                       */
+
−/*         DATE                    REMARKS                               */
+
−/*                                                                       */
+
−/*      03-01-1993      Created initial version 1.0                      */
+
−/*      04-19-1993      Verified version 1.0                             */
+
−/*                                                                       */
+
−/*************************************************************************/
+
−VOID  MBC_Cleanup(VOID *information)
+
−{
+
−
+
−MB_SUSPEND      *suspend_ptr;               /* Suspension block pointer  */
+
−NU_SUPERV_USER_VARIABLES
+
−
+
−    /* Switch to supervisor mode */
+
−    NU_SUPERVISOR_MODE();
+
−
+
−    /* Use the information pointer as a suspend pointer.  */
+
−    suspend_ptr =  (MB_SUSPEND *) information;
+
−
+
−    /* By default, indicate that the service timed-out.  It really does not
+
−       matter if this function is called from a terminate request since
+
−       the task does not resume.  */
+
−    suspend_ptr -> mb_return_status =  NU_TIMEOUT;
+
−
+
−    /* Decrement the number of tasks waiting counter.  */
+
−    (suspend_ptr -> mb_mailbox) -> mb_tasks_waiting--;
+
−
+
−    /* Unlink the suspend block from the suspension list.  */
+
−    CSC_Remove_From_List((CS_NODE **)
+
−                &((suspend_ptr -> mb_mailbox) -> mb_suspension_list),
+
−                                &(suspend_ptr -> mb_suspend_link));
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−}
+
−
+
−
+
−
+
−
+
−
+
−
+
−