view src/nucleus/pis.c @ 303:f76436d19a7a default tip

!GPRS config: fix long-standing AT+COPS chance hanging bug There has been a long-standing bug in FreeCalypso going back years: sometimes in the AT command bring-up sequence of an ACI-only MS, the AT+COPS command would produce only a power scan followed by cessation of protocol stack activity (only L1 ADC traces), instead of the expected network search sequence. This behaviour was seen in different FC firmware versions going back to Citrine, and seemed to follow some law of chance, not reliably repeatable. This bug has been tracked down and found to be specific to !GPRS configuration, stemming from our TCS2/TCS3 hybrid and reconstruction of !GPRS support that was bitrotten in TCS3.2/LoCosto version. ACI module psa_mms.c, needed only for !GPRS, was missing in the TCS3 version and had to be pulled from TCS2 - but as it turns out, there is a new field in the MMR_REG_REQ primitive that needs to be set correctly, and that psa_mms.c module is the place where this initialization needed to be added.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 08 Jun 2023 08:23:37 +0000
parents 4e78acac3d88
children
line wrap: on
line source

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

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


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


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

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


/* Define internal component function prototypes.  */

VOID    PIC_Cleanup(VOID *information);


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

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

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

    /* Move input pipe pointer into internal pointer.  */
    pipe =  (PI_PCB *) pipe_ptr;


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

#ifdef  NU_ENABLE_HISTORY

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

#endif

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      PIS_Send_To_Front_Of_Pipe                                        */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function sends a message to the front of the specified      */
/*      message pipe.  The message length is determined by the caller.   */
/*      If there are any tasks suspended on the pipe for a message, the  */
/*      message is copied into the message area of the first waiting     */
/*      task and that task is resumed.  If there is enough room in the   */
/*      pipe, the message is copied in front of all other messages.      */
/*      If there is not enough room in the pipe, suspension of the       */
/*      caller is possible.                                              */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      PISE_Send_To_Front_Of_Pipe          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 pipe                 */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pipe_ptr                            Pipe 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_PIPE_FULL                        If pipe is currently full    */
/*      NU_TIMEOUT                          If timeout on service expires*/
/*      NU_PIPE_DELETED                     If pipe was deleted during   */
/*                                            suspension                 */
/*      NU_PIPE_RESET                       If pipe 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  PIS_Send_To_Front_Of_Pipe(NU_PIPE *pipe_ptr, VOID *message,
                                        UNSIGNED size, UNSIGNED suspend)
{

R1 PI_PCB      *pipe;                       /* Pipe control block ptr    */
PI_SUSPEND      suspend_block;              /* Allocate suspension block */
PI_SUSPEND     *suspend_ptr;                /* Pointer to suspend block  */
R2 BYTE_PTR     source;                     /* Pointer to source         */
R3 BYTE_PTR     destination;                /* Pointer to destination    */
UNSIGNED        copy_size;                  /* Partial copy size         */
R4 INT          i;                          /* Working counter           */
UNSIGNED        pad = 0;                    /* Number of pad bytes       */
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 pipe pointer into internal pointer.  */
    pipe =  (PI_PCB *) pipe_ptr;


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

#ifdef  NU_ENABLE_HISTORY

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

#endif

    /* Initialize the status as successful.  */
    status =  NU_SUCCESS;

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

    /* Determine if an extra word of overhead needs to be added to the
       calculation.  */
    if (pipe -> pi_fixed_size)

        /* No overhead.  */
        i =  0;
    else
    {

        /* Variable messages have one additional word of overhead.  */
        i =  sizeof(UNSIGNED);

        /* Calculate the number of pad bytes necessary to keep the pipe
           write pointer on an UNSIGNED data element alignment.  */
        pad =  (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) *
                        sizeof(UNSIGNED)) - size;

        /* Insure that padding is included in the overhead.  */
        i =  i + ((INT) pad);

        /* Make special check to see if a suspension needs to be
           forced for a variable length message.  */
        if ((pipe -> pi_suspension_list) && (pipe -> pi_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 ((pipe -> pi_fifo_suspend) ||
                (suspend == NU_NO_SUSPEND) ||
                ((pipe -> pi_suspension_list) -> pi_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) pipe -> pi_available;
        }
    }

    /* Determine if there is enough room in the pipe for the message.  */
    if (pipe -> pi_available < (size + i))
    {

        /* pipe does not have room for the message.  Determine if
           suspension is required.  */
        if (suspend)
        {

            /* Suspension is requested.   */

            /* Increment the number of tasks waiting.  */
            pipe -> pi_tasks_waiting++;

#ifdef INCLUDE_PROVIEW
            _RTProf_DumpPipe(RT_PROF_SEND_TO_FRONT_OF_PIPE,pipe,RT_PROF_WAIT);
#endif /* INCLUDE_PROVIEW */

            /* Setup the suspend block and suspend the calling task.  */
            suspend_ptr =  &suspend_block;
            suspend_ptr -> pi_pipe =                     pipe;
            suspend_ptr -> pi_suspend_link.cs_next =     NU_NULL;
            suspend_ptr -> pi_suspend_link.cs_previous = NU_NULL;
            suspend_ptr -> pi_message_area =       (BYTE_PTR) message;
            suspend_ptr -> pi_message_size =             size;
            task =                            (TC_TCB *) TCT_Current_Thread();
            suspend_ptr -> pi_suspended_task =           task;

            /* Place the task on the urgent message suspension list.  */
            CSC_Place_On_List((CS_NODE **) &(pipe -> pi_urgent_list),
                                        &(suspend_ptr -> pi_suspend_link));

            /* Move the head pointer of the list to make this suspension the
               first in the list.  */
            pipe -> pi_urgent_list =  (PI_SUSPEND *)
                (pipe -> pi_urgent_list) -> pi_suspend_link.cs_previous;

            /* Finally, suspend the calling task. Note that the suspension call
               automatically clears the protection on the pipe.  */
            TCC_Suspend_Task((NU_TASK *) task, NU_PIPE_SUSPEND,
                                        PIC_Cleanup, suspend_ptr, suspend);

            /* Pickup the return status.  */
            status =  suspend_ptr -> pi_return_status;
        }
        else
        {

            /* Return a status of NU_PIPE_FULL because there is no
               room in the pipe for the message.  */
            status =  NU_PIPE_FULL;

#ifdef INCLUDE_PROVIEW
            _RTProf_DumpPipe(RT_PROF_SEND_TO_FRONT_OF_PIPE,pipe,RT_PROF_FAIL);
#endif /* INCLUDE_PROVIEW */

        }
    }
    else
    {

        /* Determine if a task is waiting on an empty pipe.  */
        if ((pipe -> pi_suspension_list) && (pipe -> pi_messages == 0))
        {

            /* Task is waiting on pipe for a message.  */

            /* Decrement the number of tasks waiting on pipe.  */
            pipe -> pi_tasks_waiting--;

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

            /* Remove the first suspended block from the list.  */
            suspend_ptr =  pipe -> pi_suspension_list;
            CSC_Remove_From_List((CS_NODE **) &(pipe -> pi_suspension_list),
                                          &(suspend_ptr -> pi_suspend_link));

            /* Setup the source and destination pointers.  */
            source =       (BYTE_PTR) message;
            destination =  suspend_ptr -> pi_message_area;

            /* Initialize the return status.  */
            suspend_ptr -> pi_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 -> pi_actual_size =  size;

            /* Wakeup the waiting task and check for preemption.  */
            preempt =
                TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
                                                     NU_PIPE_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 pipe and no task is waiting.  */

            /* Setup the source pointer.  */
            source =       (BYTE_PTR) message;
            destination =  pipe -> pi_read;

            /* Process according to the type of message supported.  */
            if (pipe -> pi_fixed_size)
            {

                /* Fixed-size message pipe.  */

                /* Determine if the read pointer is at the top of the pipe
                   area.  */
                if (destination == pipe -> pi_start)

                    /* Prepare to place the message in the lower part of the
                       pipe area.  */
                    destination =  pipe -> pi_end - size;
                else

                    /* Backup the length of the message from the current
                       read pointer.  */
                    destination =  destination - size;

                /* Adjust the actual read pointer before the copy is done.  */
                pipe -> pi_read =  destination;

                /* Copy the message into the pipe area.  */
                i =  (INT) size;
                do
                {
                    *(destination++) =  *(source);
                    if ((--i) == 0)
                        break;
                    source++;
                } while (1);
            }
            else
            {

                /* Variable-length message pipe.  */

                /* Calculate the number of bytes remaining from the write
                   pointer to the bottom of the pipe.  */
                copy_size =  destination - pipe -> pi_start;

                /* Determine if part of the message needs to be placed at the
                   bottom of the pipe area.  */
                if (copy_size < (size + i))

                    /* Compute the starting location for the message.  */
                    destination =  pipe -> pi_end - ((size + i) - copy_size);
                else

                    /* Compute the starting location for the message.  */
                    destination =  destination - (size + i);

                /* Adjust the actual pipe read pointer also.  */
                pipe -> pi_read =  destination;

                /* Place message size in first location.  */
                *((UNSIGNED *) destination) =  size;
                destination =  destination + sizeof(UNSIGNED);

                /* Check for a wrap-around condition on the pipe.  */
                if (destination >= pipe -> pi_end)

                    /* Wrap the write pointer back to the top of the pipe
                       area.  */
                    destination =  pipe -> pi_start;

                /* Decrement the number of bytes remaining for this
                   extra word of overhead.  */
                pipe -> pi_available =  pipe -> pi_available -
                                                        sizeof(UNSIGNED);

                /* Calculate the number of bytes remaining from the write
                   pointer to the bottom of the pipe.  */
                copy_size =  pipe -> pi_end - destination;

                /* Determine if the message needs to be wrapped around the
                   edge of the pipe area.  */
                if (copy_size >= (size + pad))
                {

                    /* 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 =  pipe -> pi_start;

                    /* Determine if there is anything left to copy.  */
                    if (size > copy_size)
                    {
                        /* Yes, there is something to copy.  */
                        i =  (INT) (size - copy_size);
                        do
                        {
                            *(destination++) =  *(source);
                            if ((--i) == 0)
                                break;
                            source++;
                        } while (1);
                    }
                }
                /* Decrement the number of available bytes.  */
                pipe -> pi_available =  pipe -> pi_available - pad;
            }

            /* Decrement the number of available bytes.  */
            pipe -> pi_available =  pipe -> pi_available - size;

            /* Increment the number of messages in the pipe.  */
            pipe -> pi_messages++;

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

        }
    }

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

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

    /* Return the completion status.  */
    return(status);
}


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      PIS_Broadcast_To_Pipe                                            */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function sends a message to all tasks waiting for a message */
/*      from the specified pipe.  If there are no tasks waiting for a    */
/*      message the service performs like a standard send request.       */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      PISE_Broadcast_To_Pipe              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 pipe                 */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pipe_ptr                            Pipe 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_PIPE_FULL                        If pipe is currently full    */
/*      NU_TIMEOUT                          If timeout on service expires*/
/*      NU_PIPE_DELETED                     If pipe was deleted during   */
/*                                            suspension                 */
/*      NU_PIPE_RESET                       If pipe 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  PIS_Broadcast_To_Pipe(NU_PIPE *pipe_ptr, VOID *message,
                                        UNSIGNED size, UNSIGNED suspend)
{

R1 PI_PCB      *pipe;                       /* Pipe control block ptr    */
PI_SUSPEND      suspend_block;              /* Allocate suspension block */
PI_SUSPEND     *suspend_ptr;                /* Pointer to suspend block  */
R2 BYTE_PTR     source;                     /* Pointer to source         */
R3 BYTE_PTR     destination;                /* Pointer to destination    */
UNSIGNED        copy_size;                  /* Partial copy size         */
UNSIGNED        pad =  0;                   /* Number of pad bytes       */
R4 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 pipe pointer into internal pointer.  */
    pipe =  (PI_PCB *) pipe_ptr;


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

#ifdef  NU_ENABLE_HISTORY

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

#endif

    /* Initialize the status as successful.  */
    status =  NU_SUCCESS;

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

    /* Determine if an extra word of overhead needs to be added to the
       calculation.  */
    if (pipe -> pi_fixed_size)

        /* No overhead.  */
        i =  0;
    else
    {

        /* Variable messages have one additional word of overhead.  */
        i =  sizeof(UNSIGNED);

        /* Calculate the number of pad bytes necessary to keep the pipe
           write pointer on an UNSIGNED data element alignment.  */
        pad =  (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) *
                sizeof(UNSIGNED)) - size;

        /* Insure that padding is included in the overhead.  */
        i =  i + ((INT) pad);

        /* Make special check to see if a suspension needs to be
           forced for a variable length message.  */
        if ((pipe -> pi_suspension_list) && (pipe -> pi_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 ((pipe -> pi_fifo_suspend) ||
                (suspend == NU_NO_SUSPEND) ||
                ((pipe -> pi_suspension_list) -> pi_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) pipe -> pi_available;
        }
    }

    /* Determine if there is enough room in the pipe for the message.  */
    if (pipe -> pi_available < (size + i))
    {

        /* pipe does not have room for the message.  Determine if
           suspension is required.  */
        if (suspend)
        {

            /* Suspension is requested.   */

            /* Increment the number of tasks waiting.  */
            pipe -> pi_tasks_waiting++;

#ifdef INCLUDE_PROVIEW
            _RTProf_DumpPipe(RT_PROF_BROADCAST_TO_PIPE,pipe,RT_PROF_WAIT);
#endif /* INCLUDE_PROVIEW */

            /* Setup the suspend block and suspend the calling task.  */
            suspend_ptr =  &suspend_block;
            suspend_ptr -> pi_pipe =                     pipe;
            suspend_ptr -> pi_suspend_link.cs_next =     NU_NULL;
            suspend_ptr -> pi_suspend_link.cs_previous = NU_NULL;
            suspend_ptr -> pi_message_area =             (BYTE_PTR) message;
            suspend_ptr -> pi_message_size =             size;
            task =                            (TC_TCB *) TCT_Current_Thread();
            suspend_ptr -> pi_suspended_task =           task;

            /* Determine if priority or FIFO suspension is associated with the
               pipe.  */
            if (pipe -> pi_fifo_suspend)
            {

                /* FIFO suspension is required.  Link the suspend block into
                   the list of suspended tasks on this pipe.  */
                CSC_Place_On_List((CS_NODE **) &(pipe -> pi_suspension_list),
                                        &(suspend_ptr -> pi_suspend_link));
            }
            else
            {

                /* Get the priority of the current thread so the suspend block
                   can be placed in the appropriate place.  */
                suspend_ptr -> pi_suspend_link.cs_priority =
                                                    TCC_Task_Priority(task);

                CSC_Priority_Place_On_List((CS_NODE **)
                                &(pipe -> pi_suspension_list),
                                        &(suspend_ptr -> pi_suspend_link));
            }

            /* Finally, suspend the calling task. Note that the suspension call
               automatically clears the protection on the pipe.  */
            TCC_Suspend_Task((NU_TASK *) task, NU_PIPE_SUSPEND,
                                        PIC_Cleanup, suspend_ptr, suspend);

            /* Pickup the return status.  */
            status =  suspend_ptr -> pi_return_status;
        }
        else
        {

            /* Return a status of NU_PIPE_FULL because there is no
               room in the pipe for the message.  */
            status =  NU_PIPE_FULL;


#ifdef INCLUDE_PROVIEW
            _RTProf_DumpPipe(RT_PROF_BROADCAST_TO_PIPE,pipe,RT_PROF_FAIL);
#endif /* INCLUDE_PROVIEW */

        }
    }
    else
    {

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

        /* Determine if a task is waiting on an empty pipe.  */
        if ((pipe -> pi_suspension_list) && (pipe -> pi_messages == 0))
        {

            /* Yes, one or more tasks are waiting for a message from this
               pipe.  */
            preempt =  0;
            do
            {

                /* Decrement the number of tasks waiting on pipe.  */
                pipe -> pi_tasks_waiting--;

                /* Remove the first suspended block from the list.  */
                suspend_ptr =  pipe -> pi_suspension_list;
                CSC_Remove_From_List((CS_NODE **)
                                &(pipe -> pi_suspension_list),
                                          &(suspend_ptr -> pi_suspend_link));

                /* Setup the source and destination pointers.  */
                source =       (BYTE_PTR) message;
                destination =  suspend_ptr -> pi_message_area;

                /* Initialize the return status.  */
                suspend_ptr -> pi_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 -> pi_actual_size =  size;

                /* Wakeup the waiting task and check for preemption.  */
                preempt =  preempt |
                 TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
                                                         NU_PIPE_SUSPEND);

                /* Move the suspend pointer to the next node, which is now
                   at the head of the list.  */
                suspend_ptr =  pipe -> pi_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 pipe and no task is waiting.  */

            /* Setup the source pointer.  */
            source =       (BYTE_PTR) message;
            destination =  pipe -> pi_write;

            /* Process according to the type of message supported.  */
            if (pipe -> pi_fixed_size)
            {

                /* Fixed-size messages are supported by this pipe.  */

                /* Loop to copy the message into the pipe area.  */
                i =  (INT) size;
                do
                {
                    *(destination++) =  *(source);
                    if ((--i) == 0)
                        break;
                    source++;
                } while (1);
            }
            else
            {

                /* Variable-size messages are supported.  Processing must
                   check for pipe wrap-around conditions.  */

                /* Place message size in first location.  */
                *((UNSIGNED *) destination) =  size;
                destination =  destination + sizeof(UNSIGNED);

                /* Check for a wrap-around condition on the pipe.  */
                if (destination >= pipe -> pi_end)

                    /* Wrap the write pointer back to the top of the pipe
                       area.  */
                    destination =  pipe -> pi_start;

                /* Decrement the number of bytes remaining for this
                   extra word of overhead.  */
                pipe -> pi_available =  pipe -> pi_available -
                                                        sizeof(UNSIGNED);

                /* Calculate the number of bytes remaining from the write
                   pointer to the bottom of the pipe.  */
                copy_size =  pipe -> pi_end - destination;

                /* Determine if the message needs to be wrapped around the
                   edge of the pipe 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 =  pipe -> pi_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 >= pipe -> pi_end)

                /* Move the write pointer to the top of the pipe area.  */
                destination =  pipe -> pi_start;

            /* Determine if the pipe supports variable-length messages.  If
               so, pad bytes are needed to keep UNSIGNED alignment.  */
            if (pad)
            {

                /* Variable-size message.  Add pad bytes to the write
                   pointer.  */

                /* Calculate the number of bytes remaining from the write
                   pointer to the bottom of the pipe.  */
                copy_size =  pipe -> pi_end - destination;

                /* If there is not enough room at the bottom of the pipe, the
                   pad bytes must be wrapped around to the top.  */
                if (copy_size <= pad)

                    /* Move write pointer to the top of the pipe and make the
                       necessary adjustment.  */
                    destination =  pipe -> pi_start + (pad - copy_size);
                else

                    /* There is enough room in the pipe to simply add the
                       the pad bytes to the write pointer.  */
                    destination =  destination + pad;

                /* Decrement the number of available bytes.  */
                pipe -> pi_available =  pipe -> pi_available - pad;
            }

            /* Update the actual write pointer.  */
            pipe -> pi_write =  destination;

            /* Decrement the number of available bytes.  */
            pipe -> pi_available =  pipe -> pi_available - size;

            /* Increment the number of messages in the pipe.  */
            pipe -> pi_messages++;
        }
    }

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

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

    /* Return the completion status.  */
    return(status);
}