gcc/ada/s-tasinf-tru64.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M . T A S K _ I N F O                      --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                           (Compiler Interface)                           --
   9 --                                                                          --
  10 --         Copyright (C) 1998-2009, Free Software Foundation, Inc.          --
  11 --                                                                          --
  12 -- GNAT 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- --
  14 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  18 --                                                                          --
  19 -- As a special exception under Section 7 of GPL version 3, you are granted --
  20 -- additional permissions described in the GCC Runtime Library Exception,   --
  21 -- version 3.1, as published by the Free Software Foundation.               --
  22 --                                                                          --
  23 -- You should have received a copy of the GNU General Public License and    --
  24 -- a copy of the GCC Runtime Library Exception along with this program;     --
  25 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  26 -- <http://www.gnu.org/licenses/>.                                          --
  27 --                                                                          --
  28 -- GNAT was originally developed  by the GNAT team at  New York University. --
  29 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  30 --                                                                          --
  31 ------------------------------------------------------------------------------
  32
  33 --  This package contains the definitions and routines associated with the
  34 --  implementation and use of the Task_Info pragma. It is specialized
  35 --  appropriately for targets that make use of this pragma.
  36
  37 --  Note: the compiler generates direct calls to this interface, via Rtsfind.
  38 --  Any changes to this interface may require corresponding compiler changes.
  39
  40 --  This unit may be used directly from an application program by providing
  41 --  an appropriate WITH, and the interface can be expected to remain stable.
  42
  43 --  This is a DEC Unix 4.0d version of this package
  44
  45 package System.Task_Info is
  46    pragma Preelaborate;
  47    pragma Elaborate_Body;
  48    --  To ensure that a body is allowed
  49
  50    -----------------------------------------
  51    -- Implementation of Task_Info Feature --
  52    -----------------------------------------
  53
  54    --  The Task_Info pragma:
  55
  56    --    pragma Task_Info (EXPRESSION);
  57
  58    --  allows the specification on a task by task basis of a value of type
  59    --  System.Task_Info.Task_Info_Type to be passed to a task when it is
  60    --  created. The specification of this type, and the effect on the task
  61    --  that is created is target dependent.
  62
  63    --  The Task_Info pragma appears within a task definition (compare the
  64    --  definition and implementation of pragma Priority). If no such pragma
  65    --  appears, then the value Unspecified_Task_Info is passed. If a pragma
  66    --  is present, then it supplies an alternative value. If the argument of
  67    --  the pragma is a discriminant reference, then the value can be set on
  68    --  a task by task basis by supplying the appropriate discriminant value.
  69
  70    --  Note that this means that the type used for Task_Info_Type must be
  71    --  suitable for use as a discriminant (i.e. a scalar or access type).
  72
  73    ------------------
  74    -- Declarations --
  75    ------------------
  76
  77    type Scope_Type is
  78      (Process_Scope,
  79       --  Contend only with threads in same process
  80
  81       System_Scope,
  82       --  Contend with all threads on same CPU
  83
  84       Default_Scope);
  85
  86    type Thread_Attributes is record
  87       Bind_To_Cpu_Number : Integer;
  88       --   -1: Do nothing
  89       --    0: Unbind
  90       --  1-N: Bind all unbound threads to this CPU
  91
  92       Contention_Scope   : Scope_Type;
  93    end record;
  94
  95    type Task_Info_Type is access all Thread_Attributes;
  96    --  Type used for passing information to task create call, using the
  97    --  Task_Info pragma. This type may be specialized for individual
  98    --  implementations, but it must be a type that can be used as a
  99    --  discriminant (i.e. a scalar or access type).
 100
 101    Unspecified_Thread_Attribute : aliased Thread_Attributes :=
 102      Thread_Attributes'(-1, Default_Scope);
 103
 104    Unspecified_Task_Info : constant Task_Info_Type :=
 105      Unspecified_Thread_Attribute'Access;
 106    --  Value passed to task in the absence of a Task_Info pragma
 107    --  Don't call new here because the tasking run time has not been
 108    --  elaborated yet, so calling Task_Lock is unsafe.
 109
 110 end System.Task_Info;