diff nuc-fw/nucleus/qus.c @ 79:947b1f473960

beginning of nuc-fw
author Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
date Sun, 11 Aug 2013 07:17:25 +0000
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nuc-fw/nucleus/qus.c	Sun Aug 11 07:17:25 2013 +0000
@@ -0,0 +1,1062 @@
+/*************************************************************************/
+/*                                                                       */
+/*               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);
+}
+
+
+
+