gcc/ada/5ftasinf.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) 1992-2000 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 2,  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.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, 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 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  This package contains the definitions and routines associated with the
  36 --  implementation of the Task_Info pragma. It is specialized appropriately
  37 --  for targets that make use of this pragma.
  38
  39 --  Note: the compiler generates direct calls to this interface, via Rtsfind.
  40 --  Any changes to this interface may require corresponding compiler changes.
  41
  42 with Interfaces.C;
  43 with System.OS_Interface;
  44 with Unchecked_Deallocation;
  45
  46 package System.Task_Info is
  47 pragma Elaborate_Body;
  48 --  To ensure that a body is allowed
  49
  50    package OSI renames System.OS_Interface;
  51
  52    -----------------------------------------
  53    -- Implementation of Task_Info Feature --
  54    -----------------------------------------
  55
  56    --  Pragma Task_Info allows an application to set the underlying
  57    --  pthread scheduling attributes for a specific task.
  58
  59    ------------------
  60    -- Declarations --
  61    ------------------
  62
  63    type Thread_Scheduling_Scope is
  64      (PTHREAD_SCOPE_PROCESS, PTHREAD_SCOPE_SYSTEM);
  65
  66    for Thread_Scheduling_Scope'Size use Interfaces.C.int'Size;
  67
  68    type Thread_Scheduling_Inheritance is
  69       (PTHREAD_EXPLICIT_SCHED, PTHREAD_INHERIT_SCHED);
  70
  71    for Thread_Scheduling_Inheritance'Size use Interfaces.C.int'Size;
  72
  73    type Thread_Scheduling_Policy is
  74       (SCHED_FIFO,   --  The first-in-first-out real-time policy
  75        SCHED_RR,     --  The round-robin real-time scheduling policy
  76        SCHED_TS);    --  The timeshare earnings based scheduling policy
  77
  78    for Thread_Scheduling_Policy'Size use Interfaces.C.int'Size;
  79    for Thread_Scheduling_Policy use
  80       (SCHED_FIFO => 1,
  81        SCHED_RR   => 2,
  82        SCHED_TS   => 3);
  83
  84    function SCHED_OTHER return Thread_Scheduling_Policy renames SCHED_TS;
  85
  86    No_Specified_Priority : constant := -1;
  87
  88    subtype Thread_Scheduling_Priority is Integer range
  89      No_Specified_Priority .. 255;
  90
  91    function Min (Policy : Interfaces.C.int) return Interfaces.C.int
  92      renames OSI.sched_get_priority_min;
  93
  94    function Max (Policy : Interfaces.C.int) return Interfaces.C.int
  95      renames OSI.sched_get_priority_max;
  96
  97    subtype FIFO_Priority is Thread_Scheduling_Priority range
  98       Thread_Scheduling_Priority (Min (OSI.SCHED_FIFO)) ..
  99       Thread_Scheduling_Priority (Max (OSI.SCHED_FIFO));
 100
 101    subtype RR_Priority is Thread_Scheduling_Priority range
 102       Thread_Scheduling_Priority (Min (OSI.SCHED_RR)) ..
 103       Thread_Scheduling_Priority (Max (OSI.SCHED_RR));
 104
 105    subtype TS_Priority is Thread_Scheduling_Priority range
 106       Thread_Scheduling_Priority (Min (OSI.SCHED_TS)) ..
 107       Thread_Scheduling_Priority (Max (OSI.SCHED_TS));
 108
 109    subtype OTHER_Priority is Thread_Scheduling_Priority range
 110       Thread_Scheduling_Priority (Min (OSI.SCHED_OTHER)) ..
 111       Thread_Scheduling_Priority (Max (OSI.SCHED_OTHER));
 112
 113    subtype CPU_Number is Integer range -1 .. Integer'Last;
 114    ANY_CPU : constant CPU_Number := CPU_Number'First;
 115
 116    type Thread_Attributes is record
 117       Scope       : Thread_Scheduling_Scope       := PTHREAD_SCOPE_PROCESS;
 118       Inheritance : Thread_Scheduling_Inheritance := PTHREAD_EXPLICIT_SCHED;
 119       Policy      : Thread_Scheduling_Policy      := SCHED_RR;
 120       Priority    : Thread_Scheduling_Priority    := No_Specified_Priority;
 121       Runon_CPU   : CPU_Number                    := ANY_CPU;
 122    end record;
 123
 124    Default_Thread_Attributes : constant Thread_Attributes :=
 125      (PTHREAD_SCOPE_PROCESS, PTHREAD_EXPLICIT_SCHED, SCHED_RR,
 126        No_Specified_Priority, ANY_CPU);
 127
 128    type Task_Info_Type is access all Thread_Attributes;
 129
 130    type Task_Image_Type is access String;
 131    --  Used to generate a meaningful identifier for tasks that are variables
 132    --  and components of variables.
 133
 134    procedure Free_Task_Image is new
 135      Unchecked_Deallocation (String, Task_Image_Type);
 136
 137    Unspecified_Task_Info : constant Task_Info_Type := null;
 138    --  Value passed to task in the absence of a Task_Info pragma
 139
 140 end System.Task_Info;