gcc/ada/4hexcpol.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
   4 --                                                                          --
   5 --                   A D A . E X C E P T I O N S . P O L L                  --
   6 --       (version supporting asynchronous abort test and time slicing)      --
   7 --                                                                          --
   8 --                                  B o d y                                 --
   9 --                                                                          --
  10 --                                                                          --
  11 --          Copyright (C) 1992-2000, Free Software Foundation, Inc.         --
  12 --                                                                          --
  13 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
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  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
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  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNARL was developed by the GNARL team at Florida State University. It is --
  32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
  33 -- State University (http://www.gnat.com).                                  --
  34 --                                                                          --
  35 ------------------------------------------------------------------------------
  36
  37 --  This version is for targets that do not support per-thread asynchronous
  38 --  signals or that do not handle async timers properly. On such targets, we
  39 --  require compilation with the -gnatP switch that activates periodic polling.
  40 --  Then in the body of the polling routine we test for asynchronous abort and
  41 --  yield periodically.
  42
  43 --  HP-UX and SCO currently use this file
  44
  45 with System.Soft_Links;
  46 --  used for Check_Abort_Status
  47
  48 separate (Ada.Exceptions)
  49
  50 ----------
  51 -- Poll --
  52 ----------
  53
  54 procedure Poll is
  55 begin
  56    if Counter = 10000 then
  57       Counter := 0;
  58       delay 0.0;
  59    else
  60       Counter := Counter + 1;
  61    end if;
  62
  63    --  Test for asynchronous abort on each poll
  64
  65    if System.Soft_Links.Check_Abort_Status.all /= 0 then
  66       raise Standard'Abort_Signal;
  67    end if;
  68 end Poll;