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1 ------------------------------------------------------------------------------
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2 -- --
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3 -- GNAT RUN-TIME COMPONENTS --
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4 -- --
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5 -- A D A . D I S P A T C H I N G --
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6 -- --
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7 -- B o d y --
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8 -- --
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9 -- Copyright (C) 2015-2017, Free Software Foundation, Inc. --
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10 -- --
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11 -- GNAT is free software; you can redistribute it and/or modify it under --
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12 -- terms of the GNU General Public License as published by the Free Soft- --
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13 -- ware Foundation; either version 3, or (at your option) any later ver- --
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14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
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17 -- --
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18 -- As a special exception under Section 7 of GPL version 3, you are granted --
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19 -- additional permissions described in the GCC Runtime Library Exception, --
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20 -- version 3.1, as published by the Free Software Foundation. --
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21 -- --
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22 -- You should have received a copy of the GNU General Public License and --
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23 -- a copy of the GCC Runtime Library Exception along with this program; --
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24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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25 -- <http://www.gnu.org/licenses/>. --
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26 -- --
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27 -- GNAT was originally developed by the GNAT team at New York University. --
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28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
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29 -- --
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30 ------------------------------------------------------------------------------
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31
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32 with Ada.Exceptions;
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33 with System.Tasking;
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34 with System.Task_Primitives.Operations;
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35
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36 package body Ada.Dispatching is
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37
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38 procedure Yield is
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39 Self_Id : constant System.Tasking.Task_Id :=
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40 System.Task_Primitives.Operations.Self;
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41
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42 begin
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43 -- If pragma Detect_Blocking is active, Program_Error must be
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44 -- raised if this potentially blocking operation is called from a
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45 -- protected action.
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46
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47 if System.Tasking.Detect_Blocking
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48 and then Self_Id.Common.Protected_Action_Nesting > 0
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49 then
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50 Ada.Exceptions.Raise_Exception
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51 (Program_Error'Identity, "potentially blocking operation");
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52 else
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53 System.Task_Primitives.Operations.Yield;
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54 end if;
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55 end Yield;
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56
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57 end Ada.Dispatching;
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