+
−/*************************************************************************/
+
−/*                                                                       */
+
−/*               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       */
+
−/*                                                                       */
+
−/*      qus.c                                          Nucleus PLUS 1.14 */
+
−/*                                                                       */
+
−/* COMPONENT                                                             */
+
−/*                                                                       */
+
−/*      QU - Queue Management                                            */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This file contains supplemental routines for the Queue           */
+
−/*      Management component.                                            */
+
−/*                                                                       */
+
−/* DATA STRUCTURES                                                       */
+
−/*                                                                       */
+
−/*      None                                                             */
+
−/*                                                                       */
+
−/* FUNCTIONS                                                             */
+
−/*                                                                       */
+
−/*      QUS_Reset_Queue                     Reset a queue                */
+
−/*      QUS_Send_To_Front_Of_Queue          Send message to queue's front*/
+
−/*      QUS_Broadcast_To_Queue              Broadcast a message to queue */
+
−/*                                                                       */
+
−/* DEPENDENCIES                                                          */
+
−/*                                                                       */
+
−/*      cs_extr.h                           Common Service functions     */
+
−/*      tc_extr.h                           Thread Control functions     */
+
−/*      qu_extr.h                           Queue 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        "qu_extr.h"                 /* Queue functions           */
+
−#include        "hi_extr.h"                 /* History functions         */
+
−#include        "profiler.h"                /* ProView interface         */
+
−
+
−
+
−/* Define internal component function prototypes.  */
+
−
+
−VOID    QUC_Cleanup(VOID *information);
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      QUS_Reset_Queue                                                  */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function resets the specified queue back to the original    */
+
−/*      state.  Any messages in the queue are discarded.  Also, any      */
+
−/*      tasks currently suspended on the queue are resumed with the      */
+
−/*      reset status.                                                    */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      QUSE_Reset_Queue                    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 queue data structures*/
+
−/*      TCT_Unprotect                       Release protection           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      queue_ptr                           Queue 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 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  QUS_Reset_Queue(NU_QUEUE *queue_ptr)
+
−{
+
−
+
−R1 QU_QCB      *queue;                      /* Queue control block ptr   */
+
−QU_SUSPEND     *suspend_ptr;                /* Suspend block pointer     */
+
−QU_SUSPEND     *next_ptr;                   /* Next suspend block pointer*/
+
−STATUS          preempt;                    /* Status for resume call    */
+
−NU_SUPERV_USER_VARIABLES
+
−
+
−    /* Move input queue pointer into internal pointer.  */
+
−    queue =  (QU_QCB *) queue_ptr;
+
−
+
−    /* Switch to supervisor mode */
+
−    NU_SUPERVISOR_MODE();
+
−
+
−#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_QUEUE_ID, (UNSIGNED) queue,
+
−                                        (UNSIGNED) 0, (UNSIGNED) 0);
+
−
+
−#endif
+
−
+
−    /* Protect against access to the queue.  */
+
−    TCT_System_Protect();
+
−
+
−    /* Pickup the suspended task suspension list.  */
+
−    suspend_ptr =  queue -> qu_suspension_list;
+
−
+
−    /* Walk the chain task(s) currently suspended on the queue.  */
+
−    preempt =  0;
+
−    while (suspend_ptr)
+
−    {
+
−
+
−        /* Resume the suspended task.  Insure that the status returned is
+
−           NU_QUEUE_RESET.  */
+
−        suspend_ptr -> qu_return_status =  NU_QUEUE_RESET;
+
−
+
−        /* Point to the next suspend structure in the link.  */
+
−        next_ptr =  (QU_SUSPEND *) (suspend_ptr -> qu_suspend_link.cs_next);
+
−
+
−        /* Resume the specified task.  */
+
−        preempt =  preempt |
+
−            TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
+
−                                                NU_QUEUE_SUSPEND);
+
−
+
−        /* Determine if the next is the same as the head pointer.  */
+
−        if (next_ptr == queue -> qu_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;
+
−    }
+
−
+
−    /* Pickup the urgent message suspension list.  */
+
−    suspend_ptr =  queue -> qu_urgent_list;
+
−
+
−    /* Walk the chain task(s) currently suspended on the queue.  */
+
−    while (suspend_ptr)
+
−    {
+
−
+
−        /* Resume the suspended task.  Insure that the status returned is
+
−           NU_QUEUE_RESET.  */
+
−        suspend_ptr -> qu_return_status =  NU_QUEUE_RESET;
+
−
+
−        /* Point to the next suspend structure in the link.  */
+
−        next_ptr =  (QU_SUSPEND *) (suspend_ptr -> qu_suspend_link.cs_next);
+
−
+
−        /* Resume the specified task.  */
+
−        preempt =  preempt |
+
−            TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
+
−                                                NU_QUEUE_SUSPEND);
+
−
+
−        /* Determine if the next is the same as the head pointer.  */
+
−        if (next_ptr == queue -> qu_urgent_list)
+
−
+
−            /* Clear the suspension pointer to signal the end of the list
+
−               traversal.  */
+
−            suspend_ptr =  NU_NULL;
+
−        else
+
−
+
−            /* Position suspend pointer to the next suspend block.  */
+
−            suspend_ptr =  next_ptr;
+
−    }
+
−
+
−    /* Initialize various elements of the queue.  */
+
−    queue -> qu_available =             queue -> qu_end - queue -> qu_start;
+
−    queue -> qu_messages =              0;
+
−    queue -> qu_read =                  queue -> qu_start;
+
−    queue -> qu_write =                 queue -> qu_start;
+
−    queue -> qu_tasks_waiting =         0;
+
−    queue -> qu_suspension_list =       NU_NULL;
+
−    queue -> qu_urgent_list =           NU_NULL;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−    _RTProf_DumpQueue(RT_PROF_RESET_QUEUE,queue,RT_PROF_OK);
+
−#endif
+
−
+
−    /* 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 queue.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return a successful completion.  */
+
−    return(NU_SUCCESS);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      QUS_Send_To_Front_Of_Queue                                       */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function sends a message to the front of the specified      */
+
−/*      message queue.  The message length is determined by the caller.  */
+
−/*      If there are any tasks suspended on the queue 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   */
+
−/*      queue, the message is copied in front of all other messages.     */
+
−/*      If there is not enough room in the queue, suspension of the      */
+
−/*      caller is possible.                                              */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      QUSE_Send_To_Front_Of_Queue         Error checking shell         */
+
−/*                                                                       */
+
−/* CALLS                                                                 */
+
−/*                                                                       */
+
−/*      CSC_Place_On_List                   Place on suspend 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         */
+
−/*      [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 queue                */
+
−/*      TCT_Unprotect                       Release protection           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      queue_ptr                           Queue control block pointer  */
+
−/*      message                             Pointer to message to send   */
+
−/*      size                                Size of message to send      */
+
−/*      suspend                             Suspension option if full    */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                          If service is successful     */
+
−/*      NU_QUEUE_FULL                       If queue is currently full   */
+
−/*      NU_TIMEOUT                          If timeout on service expires*/
+
−/*      NU_QUEUE_DELETED                    If queue was deleted during  */
+
−/*                                            suspension                 */
+
−/*      NU_QUEUE_RESET                      If queue was reset 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 interfaces to                   */
+
−/*                      match those in prototype,                        */
+
−/*                      added register options, changed                  */
+
−/*                      protection logic to reduce                       */
+
−/*                      overhead, optimized copy loop,                   */
+
−/*                      resulting in version 1.1                         */
+
−/*                                                                       */
+
−/*      03-18-1994      Verified version 1.1                             */
+
−/*                                                                       */
+
−/*************************************************************************/
+
−STATUS  QUS_Send_To_Front_Of_Queue(NU_QUEUE *queue_ptr, VOID *message,
+
−                                        UNSIGNED size, UNSIGNED suspend)
+
−{
+
−
+
−R1 QU_QCB      *queue;                      /* Queue control block ptr   */
+
−QU_SUSPEND      suspend_block;              /* Allocate suspension block */
+
−QU_SUSPEND     *suspend_ptr;                /* Pointer to suspend block  */
+
−R3 UNSIGNED_PTR source;                     /* Pointer to source         */
+
−R4 UNSIGNED_PTR destination;                /* Pointer to destination    */
+
−UNSIGNED        copy_size;                  /* Partial copy size         */
+
−R2 INT          i;                          /* Working counter           */
+
−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 queue pointer into internal pointer.  */
+
−    queue =  (QU_QCB *) queue_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_FRONT_OF_QUEUE_ID, (UNSIGNED) queue,
+
−                                        (UNSIGNED) message, (UNSIGNED) size);
+
−
+
−#endif
+
−
+
−    /* Initialize the status as successful.  */
+
−    status =  NU_SUCCESS;
+
−
+
−    /* Protect against simultaneous access to the queue.  */
+
−    TCT_System_Protect();
+
−
+
−    /* Determine if an extra word of overhead needs to be added to the
+
−       calculation.  */
+
−    if (queue -> qu_fixed_size)
+
−
+
−        /* No overhead.  */
+
−        i =  0;
+
−    else
+
−    {
+
−        /* Variable messages have one additional word of overhead.  */
+
−        i =  1;
+
−
+
−        /* Make special check to see if a suspension needs to be
+
−           forced for a variable length message.  */
+
−        if ((queue -> qu_suspension_list) && (queue -> qu_messages))
+
−        {
+
−
+
−            /* Pickup task control block pointer.  */
+
−            task =  (TC_TCB *) TCT_Current_Thread();
+
−
+
−            /* Now we know that there are other task(s) are suspended trying
+
−               to send a variable length message.  Determine whether or not
+
−               a suspension should be forced.  */
+
−            if ((queue -> qu_fifo_suspend) ||
+
−                (suspend == NU_NO_SUSPEND) ||
+
−                ((queue -> qu_suspension_list) -> qu_suspend_link.cs_priority <=
+
−                                                    TCC_Task_Priority(task)))
+
−
+
−                /* Bump the computed size to avoid placing the new variable
+
−                   length message ahead of the suspended tasks.  */
+
−                i =  (INT) queue -> qu_available;
+
−        }
+
−    }
+
−
+
−    /* Determine if there is enough room in the queue for the message.  */
+
−    if (queue -> qu_available < (size + i))
+
−    {
+
−
+
−        /* Queue does not have room for the message.  Determine if
+
−           suspension is required.  */
+
−        if (suspend)
+
−        {
+
−
+
−            /* Suspension is requested.   */
+
−
+
−            /* Increment the number of tasks waiting.  */
+
−            queue -> qu_tasks_waiting++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_SEND_TO_FRONT_OF_QUEUE,queue,RT_PROF_WAIT);
+
−#endif
+
−
+
−            /* Setup the suspend block and suspend the calling task.  */
+
−            suspend_ptr =  &suspend_block;
+
−            suspend_ptr -> qu_queue =                    queue;
+
−            suspend_ptr -> qu_suspend_link.cs_next =     NU_NULL;
+
−            suspend_ptr -> qu_suspend_link.cs_previous = NU_NULL;
+
−            suspend_ptr -> qu_message_area =             (UNSIGNED_PTR) message;
+
−            suspend_ptr -> qu_message_size =             size;
+
−            task =                            (TC_TCB *) TCT_Current_Thread();
+
−            suspend_ptr -> qu_suspended_task =           task;
+
−
+
−            /* Place the task on the urgent message suspension list.  */
+
−            CSC_Place_On_List((CS_NODE **) &(queue -> qu_urgent_list),
+
−                                        &(suspend_ptr -> qu_suspend_link));
+
−
+
−            /* Move the head pointer of the list to make this suspension the
+
−               first in the list.  */
+
−            queue -> qu_urgent_list =  (QU_SUSPEND *)
+
−                (queue -> qu_urgent_list) -> qu_suspend_link.cs_previous;
+
−
+
−            /* Finally, suspend the calling task. Note that the suspension call
+
−               automatically clears the protection on the queue.  */
+
−            TCC_Suspend_Task((NU_TASK *) task, NU_QUEUE_SUSPEND,
+
−                                        QUC_Cleanup, suspend_ptr, suspend);
+
−
+
−            /* Pickup the return status.  */
+
−            status =  suspend_ptr -> qu_return_status;
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Return a status of NU_QUEUE_FULL because there is no
+
−               room in the queue for the message.  */
+
−            status =  NU_QUEUE_FULL;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_SEND_TO_FRONT_OF_QUEUE,queue,RT_PROF_FAIL);
+
−#endif
+
−        }
+
−    }
+
−    else
+
−    {
+
−
+
−        /* Determine if a task is waiting on an empty queue.  */
+
−        if ((queue -> qu_suspension_list) && (queue -> qu_messages == 0))
+
−        {
+
−
+
−            /* Task is waiting on queue for a message.  */
+
−
+
−            /* Decrement the number of tasks waiting on queue.  */
+
−            queue -> qu_tasks_waiting--;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_SEND_TO_FRONT_OF_QUEUE,queue,RT_PROF_OK);
+
−#endif
+
−
+
−            /* Remove the first suspended block from the list.  */
+
−            suspend_ptr =  queue -> qu_suspension_list;
+
−            CSC_Remove_From_List((CS_NODE **) &(queue -> qu_suspension_list),
+
−                                          &(suspend_ptr -> qu_suspend_link));
+
−
+
−            /* Setup the source and destination pointers.  */
+
−            source =       (UNSIGNED_PTR) message;
+
−            destination =  suspend_ptr -> qu_message_area;
+
−
+
−            /* Initialize the return status.  */
+
−            suspend_ptr -> qu_return_status =  NU_SUCCESS;
+
−
+
−            /* Loop to actually copy the message.  */
+
−            i =  (INT) size;
+
−            do
+
−            {
+
−                *(destination++) =  *(source);
+
−                if ((--i) == 0)
+
−                    break;
+
−                source++;
+
−            } while (1);
+
−
+
−            /* Return the size of the message copied.  */
+
−            suspend_ptr -> qu_actual_size =  size;
+
−
+
−            /* Wakeup the waiting task and check for preemption.  */
+
−            preempt =
+
−                TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
+
−                                                           NU_QUEUE_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
+
−        {
+
−
+
−            /* There is enough room in the queue and no task is waiting.  */
+
−
+
−            /* Setup the source pointer.  */
+
−            source =       (UNSIGNED_PTR) message;
+
−            destination =  queue -> qu_read;
+
−
+
−            /* Process according to the type of message supported.  */
+
−            if (queue -> qu_fixed_size)
+
−            {
+
−
+
−                /* Fixed-size message queue.  */
+
−
+
−                /* Determine if the read pointer is at the top of the queue
+
−                   area.  */
+
−                if (destination == queue -> qu_start)
+
−
+
−                    /* Prepare to place the message in the lower part
+
−                       of the queue area.  */
+
−                    destination =  queue -> qu_end - size;
+
−                else
+
−
+
−                    /* Backup the length of a message from the current
+
−                       read pointer.  */
+
−                    destination =  destination - size;
+
−
+
−                /* Adjust the actual read pointer before the copy is done.  */
+
−                queue -> qu_read =  destination;
+
−
+
−                /* Copy the message into the queue area.  */
+
−                i =  (INT) size;
+
−                do
+
−                {
+
−                   *(destination++) =  *(source);
+
−                    if ((--i) == 0)
+
−                        break;
+
−                    source++;
+
−                } while (1);
+
−            }
+
−            else
+
−            {
+
−
+
−                /* Variable-size message queue.  */
+
−
+
−                /* Calculate the number of words remaining at the top of the
+
−                   queue.  */
+
−                copy_size =  destination - queue -> qu_start;
+
−
+
−                /* Determine if part of the message needs to be placed at the
+
−                   bottom of the queue area.  */
+
−                if (copy_size < (size + i))
+
−
+
−                    /* Compute the starting location for the message.  */
+
−                    destination =  queue -> qu_end - ((size +i) - copy_size);
+
−                else
+
−
+
−                    /* Compute the starting location for the message.  */
+
−                    destination =  destination - (size + i);
+
−
+
−                /* Adjust the actual queue read pointer also.  */
+
−                queue -> qu_read =  destination;
+
−
+
−                /* Place message size in first location.  */
+
−                *(destination++) =  size;
+
−
+
−                /* Check for a wrap-around condition on the queue.  */
+
−                if (destination >= queue -> qu_end)
+
−
+
−                    /* Wrap the write pointer back to the top of the queue
+
−                       area.  */
+
−                    destination =  queue -> qu_start;
+
−
+
−                /* Decrement the number of words remaining by 1 for this
+
−                   extra word of overhead.  */
+
−                queue -> qu_available--;
+
−
+
−                /* Calculate the number of words remaining from the
+
−                   destination pointer to the bottom of the queue.  */
+
−                copy_size =  queue -> qu_end - destination;
+
−
+
−                /* Determine if the message needs to be wrapped around the
+
−                   edge of the queue area.  */
+
−                if (copy_size >= size)
+
−                {
+
−
+
−                    /* Copy the whole message at once.  */
+
−                    i =  (INT) size;
+
−                    do
+
−                    {
+
−                        *(destination++) =  *(source);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        source++;
+
−                    } while (1);
+
−                }
+
−                else
+
−                {
+
−
+
−                    /* Copy the first half of the message.  */
+
−                    i =  (INT) copy_size;
+
−                    do
+
−                    {
+
−                        *(destination) =  *(source++);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        destination++;
+
−                    } while (1);
+
−
+
−                    /* Copy the second half of the message.  */
+
−                    destination =  queue -> qu_start;
+
−                    i =  (INT) (size - copy_size);
+
−                    do
+
−                    {
+
−                        *(destination++) =  *(source);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        source++;
+
−                    } while (1);
+
−                }
+
−            }
+
−
+
−            /* Decrement the number of available words.  */
+
−            queue -> qu_available =  queue -> qu_available - size;
+
−
+
−            /* Increment the number of messages in the queue.  */
+
−            queue -> qu_messages++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_SEND_TO_FRONT_OF_QUEUE,queue,RT_PROF_OK);
+
−#endif
+
−
+
−        }
+
−    }
+
−
+
−    /* Release protection against access to the queue.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return the completion status.  */
+
−    return(status);
+
−}
+
−
+
−
+
−/*************************************************************************/
+
−/*                                                                       */
+
−/* FUNCTION                                                              */
+
−/*                                                                       */
+
−/*      QUS_Broadcast_To_Queue                                           */
+
−/*                                                                       */
+
−/* DESCRIPTION                                                           */
+
−/*                                                                       */
+
−/*      This function sends a message to all tasks waiting for a message */
+
−/*      from the specified queue.  If there are no tasks waiting for a   */
+
−/*      message the service performs like a standard send request.       */
+
−/*                                                                       */
+
−/* CALLED BY                                                             */
+
−/*                                                                       */
+
−/*      Application                                                      */
+
−/*      QUSE_Broadcast_To_Queue             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 queue                */
+
−/*      TCT_Unprotect                       Release protection           */
+
−/*                                                                       */
+
−/* INPUTS                                                                */
+
−/*                                                                       */
+
−/*      queue_ptr                           Queue control block pointer  */
+
−/*      message                             Pointer to message to send   */
+
−/*      size                                Size of message to send      */
+
−/*      suspend                             Suspension option if full    */
+
−/*                                                                       */
+
−/* OUTPUTS                                                               */
+
−/*                                                                       */
+
−/*      NU_SUCCESS                          If service is successful     */
+
−/*      NU_QUEUE_FULL                       If queue is currently full   */
+
−/*      NU_TIMEOUT                          If timeout on service expires*/
+
−/*      NU_QUEUE_DELETED                    If queue was deleted during  */
+
−/*                                            suspension                 */
+
−/*      NU_QUEUE_RESET                      If queue was reset 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 interfaces to                   */
+
−/*                      match those in prototype,                        */
+
−/*                      added register options, changed                  */
+
−/*                      protection logic to reduce                       */
+
−/*                      overhead, optimized copy loop,                   */
+
−/*                      resulting in version 1.1                         */
+
−/*                                                                       */
+
−/*      03-18-1994      Verified version 1.1                             */
+
−/*                                                                       */
+
−/*************************************************************************/
+
−STATUS  QUS_Broadcast_To_Queue(NU_QUEUE *queue_ptr, VOID *message,
+
−                                        UNSIGNED size, UNSIGNED suspend)
+
−{
+
−
+
−R1 QU_QCB      *queue;                      /* Queue control block ptr   */
+
−QU_SUSPEND      suspend_block;              /* Allocate suspension block */
+
−QU_SUSPEND     *suspend_ptr;                /* Pointer to suspend block  */
+
−R3 UNSIGNED_PTR source;                     /* Pointer to source         */
+
−R4 UNSIGNED_PTR destination;                /* Pointer to destination    */
+
−UNSIGNED        copy_size;                  /* Partial copy size         */
+
−R2 INT          i;                          /* Working counter           */
+
−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 queue pointer into internal pointer.  */
+
−    queue =  (QU_QCB *) queue_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_BROADCAST_TO_QUEUE_ID, (UNSIGNED) queue,
+
−                                        (UNSIGNED) message, (UNSIGNED) size);
+
−
+
−#endif
+
−
+
−    /* Initialize the status as successful.  */
+
−    status =  NU_SUCCESS;
+
−
+
−    /* Protect against simultaneous access to the queue.  */
+
−    TCT_System_Protect();
+
−
+
−    /* Determine if an extra word of overhead needs to be added to the
+
−       calculation.  */
+
−    if (queue -> qu_fixed_size)
+
−
+
−        /* No overhead.  */
+
−        i =  0;
+
−    else
+
−    {
+
−        /* Variable messages have one additional word of overhead.  */
+
−        i =  1;
+
−
+
−        /* Make special check to see if a suspension needs to be
+
−           forced for a variable length message.  */
+
−        if ((queue -> qu_suspension_list) && (queue -> qu_messages))
+
−        {
+
−
+
−            /* Pickup task control block pointer.  */
+
−            task =  (TC_TCB *) TCT_Current_Thread();
+
−
+
−            /* Now we know that there are other task(s) are suspended trying
+
−               to send a variable length message.  Determine whether or not
+
−               a suspension should be forced.  */
+
−            if ((queue -> qu_fifo_suspend) ||
+
−                (suspend == NU_NO_SUSPEND) ||
+
−                ((queue -> qu_suspension_list) -> qu_suspend_link.cs_priority <=
+
−                                                    TCC_Task_Priority(task)))
+
−
+
−                /* Bump the computed size to avoid placing the new variable
+
−                   length message ahead of the suspended tasks.  */
+
−                i =  (INT) queue -> qu_available;
+
−        }
+
−    }
+
−
+
−    /* Determine if there is enough room in the queue for the message.  */
+
−    if (queue -> qu_available < (size + i))
+
−    {
+
−
+
−        /* Queue does not have room for the message.  Determine if
+
−           suspension is required.  */
+
−        if (suspend)
+
−        {
+
−
+
−            /* Suspension is requested.   */
+
−
+
−            /* Increment the number of tasks waiting.  */
+
−            queue -> qu_tasks_waiting++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_BROADCAST_TO_QUEUE,queue,RT_PROF_WAIT);
+
−#endif
+
−
+
−            /* Setup the suspend block and suspend the calling task.  */
+
−            suspend_ptr = &suspend_block;
+
−            suspend_ptr -> qu_queue =                    queue;
+
−            suspend_ptr -> qu_suspend_link.cs_next =     NU_NULL;
+
−            suspend_ptr -> qu_suspend_link.cs_previous = NU_NULL;
+
−            suspend_ptr -> qu_message_area =           (UNSIGNED_PTR) message;
+
−            suspend_ptr -> qu_message_size =             size;
+
−            task =                            (TC_TCB *) TCT_Current_Thread();
+
−            suspend_ptr -> qu_suspended_task =           task;
+
−
+
−            /* Determine if priority or FIFO suspension is associated with the
+
−               queue.  */
+
−            if (queue -> qu_fifo_suspend)
+
−            {
+
−
+
−                /* FIFO suspension is required.  Link the suspend block into
+
−                   the list of suspended tasks on this queue.  */
+
−                CSC_Place_On_List((CS_NODE **) &(queue -> qu_suspension_list),
+
−                                        &(suspend_ptr -> qu_suspend_link));
+
−            }
+
−            else
+
−            {
+
−
+
−                /* Get the priority of the current thread so the suspend block
+
−                   can be placed in the appropriate place.  */
+
−                suspend_ptr -> qu_suspend_link.cs_priority =
+
−                                                      TCC_Task_Priority(task);
+
−
+
−                CSC_Priority_Place_On_List((CS_NODE **)
+
−                                &(queue -> qu_suspension_list),
+
−                                        &(suspend_ptr -> qu_suspend_link));
+
−            }
+
−
+
−            /* Finally, suspend the calling task. Note that the suspension call
+
−               automatically clears the protection on the queue.  */
+
−            TCC_Suspend_Task((NU_TASK *) task, NU_QUEUE_SUSPEND,
+
−                                        QUC_Cleanup, suspend_ptr, suspend);
+
−
+
−            /* Pickup the return status.  */
+
−            status =  suspend_ptr -> qu_return_status;
+
−        }
+
−        else
+
−        {
+
−
+
−            /* Return a status of NU_QUEUE_FULL because there is no
+
−               room in the queue for the message.  */
+
−            status =  NU_QUEUE_FULL;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−            _RTProf_DumpQueue(RT_PROF_BROADCAST_TO_QUEUE,queue,RT_PROF_FAIL);
+
−#endif
+
−
+
−        }
+
−    }
+
−    else
+
−    {
+
−
+
−        /* Determine if a task is waiting on an empty queue.  */
+
−        if ((queue -> qu_suspension_list) && (queue -> qu_messages == 0))
+
−        {
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−        _RTProf_DumpQueue(RT_PROF_BROADCAST_TO_QUEUE,queue,RT_PROF_OK);
+
−#endif
+
−
+
−            /* Yes, one or more tasks are waiting for a message from this
+
−               queue.  */
+
−            preempt =  0;
+
−            do
+
−            {
+
−
+
−                /* Decrement the number of tasks waiting on queue.  */
+
−                queue -> qu_tasks_waiting--;
+
−
+
−                /* Remove the first suspended block from the list.  */
+
−                suspend_ptr =  queue -> qu_suspension_list;
+
−                CSC_Remove_From_List((CS_NODE **)
+
−                                &(queue -> qu_suspension_list),
+
−                                          &(suspend_ptr -> qu_suspend_link));
+
−
+
−                /* Setup the source and destination pointers.  */
+
−                source =       (UNSIGNED_PTR) message;
+
−                destination =  suspend_ptr -> qu_message_area;
+
−
+
−                /* Initialize the return status.  */
+
−                suspend_ptr -> qu_return_status =  NU_SUCCESS;
+
−
+
−                /* Loop to actually copy the message.  */
+
−                i =  (INT) size;
+
−                do
+
−                {
+
−                    *(destination++) =  *(source);
+
−                    if ((--i) == 0)
+
−                        break;
+
−                    source++;
+
−                } while (1);
+
−
+
−                /* Return the size of the message copied.  */
+
−                suspend_ptr -> qu_actual_size =  size;
+
−
+
−                /* Wakeup the waiting task and check for preemption.  */
+
−                preempt =  preempt |
+
−                 TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
+
−                                                         NU_QUEUE_SUSPEND);
+
−
+
−                /* Move the suspend pointer to the next node, which is now
+
−                   at the head of the list.  */
+
−                suspend_ptr =  queue -> qu_suspension_list;
+
−            } while (suspend_ptr);
+
−
+
−            /* 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
+
−        {
+
−
+
−            /* There is enough room in the queue and no task is waiting.  */
+
−
+
−            /* Setup the source pointer.  */
+
−            source =       (UNSIGNED_PTR) message;
+
−            destination =  queue -> qu_write;
+
−
+
−            /* Process according to the type of message supported.  */
+
−            if (queue -> qu_fixed_size)
+
−            {
+
−
+
−                /* Fixed-size messages are supported by this queue.  */
+
−
+
−                /* Loop to copy the message into the queue area.  */
+
−                i =  (INT) size;
+
−                do
+
−                {
+
−                   *(destination++) =  *(source);
+
−                    if ((--i) == 0)
+
−                        break;
+
−                    source++;
+
−                } while (1);
+
−            }
+
−            else
+
−            {
+
−
+
−                /* Variable-size messages are supported.  Processing must
+
−                   check for queue wrap-around conditions.  */
+
−
+
−                /* Place message size in first location.  */
+
−                *(destination++) =  size;
+
−
+
−                /* Check for a wrap-around condition on the queue.  */
+
−                if (destination >= queue -> qu_end)
+
−
+
−                    /* Wrap the write pointer back to the top of the queue
+
−                       area.  */
+
−                    destination =  queue -> qu_start;
+
−
+
−                /* Decrement the number of words remaining by 1 for this
+
−                   extra word of overhead.  */
+
−                queue -> qu_available--;
+
−
+
−                /* Calculate the number of words remaining from the write
+
−                   pointer to the bottom of the queue.  */
+
−                copy_size =  queue -> qu_end - destination;
+
−
+
−                /* Determine if the message needs to be wrapped around the
+
−                   edge of the queue area.  */
+
−                if (copy_size >= size)
+
−                {
+
−
+
−                    /* Copy the whole message at once.  */
+
−                    i =  (INT) size;
+
−                    do
+
−                    {
+
−                        *(destination++) =  *(source);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        source++;
+
−                    } while(1);
+
−                }
+
−                else
+
−                {
+
−
+
−                    /* Copy the first half of the message.  */
+
−                    i =  (INT) copy_size;
+
−                    do
+
−                    {
+
−                        *(destination) =  *(source++);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        destination++;
+
−                    } while (1);
+
−
+
−                    /* Copy the second half of the message.  */
+
−                    destination =  queue -> qu_start;
+
−                    i =  (INT) (size - copy_size);
+
−                    do
+
−                    {
+
−                        *(destination++) =  *(source);
+
−                        if ((--i) == 0)
+
−                            break;
+
−                        source++;
+
−                    } while (1);
+
−                }
+
−            }
+
−
+
−            /* Check again for wrap-around condition on the write pointer. */
+
−            if (destination >= queue -> qu_end)
+
−
+
−                /* Move the write pointer to the top of the queue area.  */
+
−                queue -> qu_write =  queue -> qu_start;
+
−            else
+
−
+
−                /* Simply copy the last position of the destination pointer
+
−                   into the write pointer.  */
+
−                queue -> qu_write =  destination;
+
−
+
−            /* Decrement the number of available words.  */
+
−            queue -> qu_available =  queue -> qu_available - size;
+
−
+
−            /* Increment the number of messages in the queue.  */
+
−            queue -> qu_messages++;
+
−
+
−#ifdef INCLUDE_PROVIEW
+
−        _RTProf_DumpQueue(RT_PROF_BROADCAST_TO_QUEUE,queue,RT_PROF_OK);
+
−#endif
+
−        }
+
−    }
+
−
+
−    /* Release protection against access to the queue.  */
+
−    TCT_Unprotect();
+
−
+
−    /* Return to user mode */
+
−    NU_USER_MODE();
+
−
+
−    /* Return the completion status.  */
+
−    return(status);
+
−}
+
−
+
−
+
−
+
−