gcc/ada/a-excpol-interix.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                 GNAT 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 --          Copyright (C) 1992-2005, Free Software Foundation, Inc.         --
  11 --                                                                          --
  12 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
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  18 -- for  more details.  You should have  received  a copy of the GNU General --
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  21 -- Boston, MA 02110-1301, USA.                                              --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNARL was developed by the GNARL team at Florida State University.       --
  31 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  This version is for targets that do not support per-thread asynchronous
  36 --  signals or that do not handle async timers properly. On such targets, we
  37 --  require compilation with the -gnatP switch that activates periodic polling.
  38 --  Then in the body of the polling routine we test for asynchronous abort and
  39 --  yield periodically.
  40
  41 --  This is currently used only by Interix
  42
  43 pragma Warnings (Off);
  44 --  Allow withing of non-Preelaborated units in Ada 2005 mode where this
  45 --  package will be categorized as Preelaborate. See AI-362 for details.
  46 --  It is safe in the context of the run-time to violate the rules!
  47
  48 with System.Soft_Links;
  49 --  used for Check_Abort_Status
  50
  51 pragma Warnings (On);
  52
  53 separate (Ada.Exceptions)
  54
  55 ----------
  56 -- Poll --
  57 ----------
  58
  59 procedure Poll is
  60 begin
  61    if Counter = 10000 then
  62       Counter := 0;
  63       delay 0.0;
  64    else
  65       Counter := Counter + 1;
  66    end if;
  67
  68    --  Test for asynchronous abort on each poll
  69
  70    if System.Soft_Links.Check_Abort_Status.all /= 0 then
  71       raise Standard'Abort_Signal;
  72    end if;
  73 end Poll;