HPlogo 900 Series HP 3000 Computer Systems: MPE/iX Architected Interface Facility: Operating System Reference Manual > Appendix C Programming Examples

Example 4 - ASYNC2, asynchronous ports

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$standard_level 'ext_modcal'$

{-----------------------------------------------------------------------

   program ASYNC2

------------------------------------------------------------------------



PURPOSE:



This is a simple program to illustrate the use of asynchronous ports.



1.  Call GETPRIVMODE to gain user privilege level 2

2.  Open a synchronous port named 'aifport2' for receive access.

3.  Call AIFPORTRECEIVE on 'aifport2' to wait for message to open

    asynchronous port 'aifport1'.

4.  After message arrives, AIFPORTOPEN the asynchronous port named

    'aifport1' for send access.

5.  Use AIFPORTSEND to send multiple messages to 'aifport1'.

6.  Close the ports.

7.  Call GETUSERMODE.



PARAMETERS: None.



------------------------------------------------------------------------}



program ASYNC2 (input,output);



type



              status_type = record

                               case boolean of

                                  true  : (all    : integer);

                                  false : (info   : shortint;

                                           subsys : shortint);

                               end;



   item_array_type        = array [1..3] of globalanyptr;

   itemnum_array_type     = array [1..3] of integer;

   item_status_array_type = array [1..3] of status_type;

   name_type              = packed array [1..16] of char;

   message_buffer_type    = packed array [1..80] of char;
{-----------------------------------------------------------------------

  declare structured constants to initialize arrays used in various

  AIF procedure calls

------------------------------------------------------------------------}



const

   Init_Item_Array        = item_array_type

                               [3 of nil];



   Init_Itemnum_Array     = itemnum_array_type

                               [3 of 0];



   Init_Item_Status_Array = item_status_array_type

                               [3 of status_type

                                  [info   : 0,

                                   subsys : 0]];



var

   accessmode             : integer;

   base                   : integer;

   count_string           : string[6];

   envelope_code          : integer;

   index                  : integer;

   interval               : real;

   itemnum_ports          : itemnum_array_type;

   item_ports             : item_array_type;

   item_status_ports      : item_status_array_type;

   maxmsgsize             : integer;

   message_buffer         : message_buffer_type;

   message_id             : integer;

   message_length         : integer;

   message_string         : string[40];

   numchar                : shortint;

   overall_status         : status_type;

   portid1                : integer;

   portid2                : integer;

   portname               : name_type;

   portpass               : name_type;

   timeoutseconds         : integer;

   user_id                : integer;
function  ASCII         : shortint; intrinsic;

procedure GETPRIVMODE;    intrinsic;

procedure GETUSERMODE;    intrinsic;

procedure PAUSE;          intrinsic;

procedure QUIT;           intrinsic;

$sysintr 'aifintr'$

procedure AIFPORTCLOSE;   intrinsic;

function  AIFPORTOPEN   : integer; intrinsic;

procedure AIFPORTRECEIVE; intrinsic;

procedure AIFPORTSEND;    intrinsic;



{-----------------------------------------------------------------------

   procedure ERROR_IN_CALL

------------------------------------------------------------------------



   PURPOSE:

     This procedure will accept an intrinsic call name and status

     variable. It will output a message naming the offending call

     and status information and subsystem parameters. It will call

     QUIT to terminate the calling program and child processes.



   PARAMETERS:

    name   - name of erroring AIF or intrinsic call

    status - status of call

    item_status_array - array of status values for item list



-----------------------------------------------------------------------}

procedure ERROR_IN_CALL (     name              : name_type;

                              status            : status_type;

                          var item_status_array : item_status_array_type)

option extensible 2;



var

   index   : shortint;

   quitnum : integer;



begin { ERROR_IN_CALL }

   writeln ('Error in ',name);

   writeln ('Overall status info =',status.info, ' subsys =',

             status.subsys);

   if status.info > 0 then

      for index := 1 to status.info do

         writeln ('Index: ',index,' info =',item_status_array[index].info,

                  ' subsys =',item_status_array[index].subsys);

   quitnum := 516;

   QUIT (quitnum);

end; { ERROR_IN_CALL }
begin    {ASYNC2 body}

{-----------------------------------------------------------------------

1.  Call GETPRIVMODE to gain user privilege level 2

------------------------------------------------------------------------}

GETPRIVMODE;



{-----------------------------------------------------------------------

2.  Open a synchronous port named 'aifport2' for receive access.

------------------------------------------------------------------------}

writeln ('Enter a valid user ID:');

readln(user_id);



portname          := 'aifport2        ';

portpass          := 'aifpass2        ';

accessmode        := 1;                    { receive access }

itemnum_ports     := Init_Itemnum_Array;   { zero array }

item_ports        := Init_Item_Array;

item_status_ports := Init_Item_Status_Array;

maxmsgsize        := 80;                   { message size   }

itemnum_ports [1] := 11202;                { next element initialized to 0 }

item_ports [1]    := addr(maxmsgsize);



portid2 := AIFPORTOPEN(overall_status,

                       portname,

                       portpass,

                       accessmode,

                       user_id,

                       itemnum_ports,

                       item_ports,

                       item_status_ports);

if overall_status.all <> 0 then

   ERROR_IN_CALL('AIFPORTOPEN #2',overall_status,item_status_ports);



{-----------------------------------------------------------------------

3.  Call AIFPORTRECEIVE on 'aifport2' to wait for message to open

    asynchronous port 'aifport1'. Defaults to waited receive.

------------------------------------------------------------------------}

message_buffer    := ' ';

message_length    := 80;

itemnum_ports     := Init_Itemnum_Array;   { zero array }

item_ports        := Init_Item_Array;

item_status_ports := Init_Item_Status_Array;

AIFPORTRECEIVE ( overall_status,

                 portid2,

                 message_buffer,

                 message_length);

if overall_status.all <> 0 then

   ERROR_IN_CALL('AIFPORTRECEIVE',overall_status,item_status_ports);



writeln ('AIFPORTRECEIVE (complete) - ', message_buffer );
{-----------------------------------------------------------------------

4.  After message arrives, AIFPORTOPEN the asynchronous port named

    'aifport1' for send access.

------------------------------------------------------------------------}

portname          := 'aifport1        ';

portpass          := 'aifpass1        ';

accessmode        := 2;                    { send access    }

user_id           := 555;

itemnum_ports     := Init_Itemnum_Array;   { zero array }

item_ports        := Init_Item_Array;

item_status_ports := Init_Item_Status_Array;

maxmsgsize        := 80;                   { message size   }

itemnum_ports [1] := 11202;                { next element initialized to 0 }

item_ports [1]    := addr(maxmsgsize);



portid1 := AIFPORTOPEN(overall_status,

                       portname,

                       portpass,

                       accessmode,

                       user_id,

                       itemnum_ports,

                       item_ports,

                       item_status_ports);

if overall_status.all <> 0 then

   ERROR_IN_CALL('AIFPORTOPEN #1',overall_status,item_status_ports);



for index := 1 to 32 do

  begin { for repeat send messages }

    message_buffer    := '';

    message_string    := '';

    base              := 10;

    numchar           := ASCII(index,base,count_string);

    SETSTRLEN(count_string,numchar);

    message_string    := 'AIFPORT1 send message # ' + count_string;

    STRMOVE (STRLEN(message_string),message_string,1,message_buffer,1);

    message_length    := 40;

    itemnum_ports     := Init_Itemnum_Array;   { zero array }

    item_ports        := Init_Item_Array;

    item_status_ports := Init_Item_Status_Array;

    timeoutseconds    := -1;            { nowait send }

    itemnum_ports[1]  := 11101;         { next element initialized to 0 }

    item_ports[1]     := ADDR(timeoutseconds);

    AIFPORTSEND       ( overall_status,

                        portid1,

                        message_buffer,

                        message_length,

                        ,

                        ,

                        itemnum_ports,

                        item_ports,

                        item_status_ports);

    if overall_status.all <> 0 then

      ERROR_IN_CALL('AIFPORTSEND',overall_status);

  end;  { for repeat send messages }



{-----------------------------------------------------------------------

6.  Close the ports.

-----------------------------------------------------------------------}

AIFPORTCLOSE ( portid2,

               accessmode,

               overall_status);

if overall_status.all <> 0 then

   ERROR_IN_CALL('AIFPORTCLOSE',overall_status);

AIFPORTCLOSE ( portid1,

               accessmode,

               overall_status);

if overall_status.all <> 0 then

   ERROR_IN_CALL('AIFPORTCLOSE #2',overall_status);



{-----------------------------------------------------------------------

7.  Call GETUSERMODE

------------------------------------------------------------------------}

GETUSERMODE;

writeln ('ASYNC2 terminated')

end.
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