File : s-tasinf-solaris.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 -- --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This package contains the definitions and routines associated with the
33 -- implementation and use of the Task_Info pragma. It is specialized
34 -- appropriately for targets that make use of this pragma.
35
36 -- Note: the compiler generates direct calls to this interface, via Rtsfind.
37 -- Any changes to this interface may require corresponding compiler changes.
38
39 -- The functionality in this unit is now provided by the predefined package
40 -- System.Multiprocessors and the CPU aspect. This package is obsolescent.
41
42 -- This is the Solaris (native) version of this module
43
44 with System.OS_Interface;
45
46 package System.Task_Info is
47 pragma Obsolescent (Task_Info, "use System.Multiprocessors and CPU aspect");
48 pragma Preelaborate;
49 pragma Elaborate_Body;
50 -- To ensure that a body is allowed
51
52 -----------------------------------------------------
53 -- Binding of Tasks to LWPs and LWPs to processors --
54 -----------------------------------------------------
55
56 -- The Solaris implementation of the GNU Low-Level Interface (GNULLI)
57 -- implements each Ada task as a Solaris thread. The Solaris thread
58 -- library distributes threads across one or more LWPs (Light Weight
59 -- Process) that are members of the same process. Solaris distributes
60 -- processes and LWPs across the available CPUs on a given machine. The
61 -- pragma Task_Info provides the mechanism to control the distribution
62 -- of tasks to LWPs, and LWPs to processors.
63
64 -- Each thread has a number of attributes that dictate it's scheduling.
65 -- These attributes are:
66 --
67 -- New_LWP: whether a new LWP is created for this thread.
68 --
69 -- Bound_To_LWP: whether the thread is bound to a specific LWP
70 -- for its entire lifetime.
71 --
72 -- CPU: the CPU number associated to the LWP
73 --
74
75 -- The Task_Info pragma:
76
77 -- pragma Task_Info (EXPRESSION);
78
79 -- allows the specification on a task by task basis of a value of type
80 -- System.Task_Info.Task_Info_Type to be passed to a task when it is
81 -- created. The specification of this type, and the effect on the task
82 -- that is created is target dependent.
83
84 -- The Task_Info pragma appears within a task definition (compare the
85 -- definition and implementation of pragma Priority). If no such pragma
86 -- appears, then the value Unspecified_Task_Info is passed. If a pragma
87 -- is present, then it supplies an alternative value. If the argument of
88 -- the pragma is a discriminant reference, then the value can be set on
89 -- a task by task basis by supplying the appropriate discriminant value.
90
91 -- Note that this means that the type used for Task_Info_Type must be
92 -- suitable for use as a discriminant (i.e. a scalar or access type).
93
94 -----------------------
95 -- Thread Attributes --
96 -----------------------
97
98 subtype CPU_Number is System.OS_Interface.processorid_t;
99
100 CPU_UNCHANGED : constant CPU_Number := System.OS_Interface.PBIND_QUERY;
101 -- Do not bind the LWP to a specific processor
102
103 ANY_CPU : constant CPU_Number := System.OS_Interface.PBIND_NONE;
104 -- Bind the LWP to any processor
105
106 Invalid_CPU_Number : exception;
107
108 type Thread_Attributes (New_LWP : Boolean) is record
109 Bound_To_LWP : Boolean := True;
110 case New_LWP is
111 when False =>
112 null;
113 when True =>
114 CPU : CPU_Number := CPU_UNCHANGED;
115 end case;
116 end record;
117
118 Default_Thread_Attributes : constant Thread_Attributes := (False, True);
119
120 function Unbound_Thread_Attributes
121 return Thread_Attributes;
122
123 function Bound_Thread_Attributes
124 return Thread_Attributes;
125
126 function Bound_Thread_Attributes (CPU : CPU_Number)
127 return Thread_Attributes;
128
129 type Task_Info_Type is access all Thread_Attributes;
130
131 function New_Unbound_Thread_Attributes
132 return Task_Info_Type;
133
134 function New_Bound_Thread_Attributes
135 return Task_Info_Type;
136
137 function New_Bound_Thread_Attributes (CPU : CPU_Number)
138 return Task_Info_Type;
139
140 Unspecified_Task_Info : constant Task_Info_Type := null;
141
142 end System.Task_Info;