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 --                                                                          --
  11 --          Copyright (C) 1992-2000 Free Software Foundation, Inc.          --
  12 --                                                                          --
  13 -- GNAT 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- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  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 --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 --  This package contains the definitions and routines associated with the
  37 --  implementation of the Task_Info pragma. It is specialized appropriately
  38 --  for targets that make use of this pragma.
  39
  40 --  Note: the compiler generates direct calls to this interface, via Rtsfind.
  41 --  Any changes to this interface may require corresponding compiler changes.
  42
  43 with Interfaces.C;
  44 with System.OS_Interface;
  45 with Unchecked_Deallocation;
  46
  47 package System.Task_Info is
  48 pragma Elaborate_Body;
  49 --  To ensure that a body is allowed
  50
  51    package OSI renames System.OS_Interface;
  52
  53    -----------------------------------------
  54    -- Implementation of Task_Info Feature --
  55    -----------------------------------------
  56
  57    --  Pragma Task_Info allows an application to set the underlying
  58    --  pthread scheduling attributes for a specific task.
  59
  60    ------------------
  61    -- Declarations --
  62    ------------------
  63
  64    type Thread_Scheduling_Scope is
  65      (PTHREAD_SCOPE_PROCESS, PTHREAD_SCOPE_SYSTEM);
  66
  67    for Thread_Scheduling_Scope'Size use Interfaces.C.int'Size;
  68
  69    type Thread_Scheduling_Inheritance is
  70       (PTHREAD_EXPLICIT_SCHED, PTHREAD_INHERIT_SCHED);
  71
  72    for Thread_Scheduling_Inheritance'Size use Interfaces.C.int'Size;
  73
  74    type Thread_Scheduling_Policy is
  75       (SCHED_FIFO,   --  The first-in-first-out real-time policy
  76        SCHED_RR,     --  The round-robin real-time scheduling policy
  77        SCHED_TS);    --  The timeshare earnings based scheduling policy
  78
  79    for Thread_Scheduling_Policy'Size use Interfaces.C.int'Size;
  80    for Thread_Scheduling_Policy use
  81       (SCHED_FIFO => 1,
  82        SCHED_RR   => 2,
  83        SCHED_TS   => 3);
  84
  85    function SCHED_OTHER return Thread_Scheduling_Policy renames SCHED_TS;
  86
  87    No_Specified_Priority : constant := -1;
  88
  89    subtype Thread_Scheduling_Priority is Integer range
  90      No_Specified_Priority .. 255;
  91
  92    function Min (Policy : Interfaces.C.int) return Interfaces.C.int
  93      renames OSI.sched_get_priority_min;
  94
  95    function Max (Policy : Interfaces.C.int) return Interfaces.C.int
  96      renames OSI.sched_get_priority_max;
  97
  98    subtype FIFO_Priority is Thread_Scheduling_Priority range
  99       Thread_Scheduling_Priority (Min (OSI.SCHED_FIFO)) ..
 100       Thread_Scheduling_Priority (Max (OSI.SCHED_FIFO));
 101
 102    subtype RR_Priority is Thread_Scheduling_Priority range
 103       Thread_Scheduling_Priority (Min (OSI.SCHED_RR)) ..
 104       Thread_Scheduling_Priority (Max (OSI.SCHED_RR));
 105
 106    subtype TS_Priority is Thread_Scheduling_Priority range
 107       Thread_Scheduling_Priority (Min (OSI.SCHED_TS)) ..
 108       Thread_Scheduling_Priority (Max (OSI.SCHED_TS));
 109
 110    subtype OTHER_Priority is Thread_Scheduling_Priority range
 111       Thread_Scheduling_Priority (Min (OSI.SCHED_OTHER)) ..
 112       Thread_Scheduling_Priority (Max (OSI.SCHED_OTHER));
 113
 114    subtype CPU_Number is Integer range -1 .. Integer'Last;
 115    ANY_CPU : constant CPU_Number := CPU_Number'First;
 116
 117    type Thread_Attributes is record
 118       Scope       : Thread_Scheduling_Scope       := PTHREAD_SCOPE_PROCESS;
 119       Inheritance : Thread_Scheduling_Inheritance := PTHREAD_EXPLICIT_SCHED;
 120       Policy      : Thread_Scheduling_Policy      := SCHED_RR;
 121       Priority    : Thread_Scheduling_Priority    := No_Specified_Priority;
 122       Runon_CPU   : CPU_Number                    := ANY_CPU;
 123    end record;
 124
 125    Default_Thread_Attributes : constant Thread_Attributes :=
 126      (PTHREAD_SCOPE_PROCESS, PTHREAD_EXPLICIT_SCHED, SCHED_RR,
 127        No_Specified_Priority, ANY_CPU);
 128
 129    type Task_Info_Type is access all Thread_Attributes;
 130
 131    type Task_Image_Type is access String;
 132    --  Used to generate a meaningful identifier for tasks that are variables
 133    --  and components of variables.
 134
 135    procedure Free_Task_Image is new
 136      Unchecked_Deallocation (String, Task_Image_Type);
 137
 138    Unspecified_Task_Info : constant Task_Info_Type := null;
 139    --  Value passed to task in the absence of a Task_Info pragma
 140
 141 end System.Task_Info;