1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . T A S K _ I N F O --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2003 Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains the definitions and routines associated with the
-- implementation and use of the Task_Info pragma. It is specialized
-- appropriately for targets that make use of this pragma.
-- Note: the compiler generates direct calls to this interface, via Rtsfind.
-- Any changes to this interface may require corresponding compiler changes.
-- This unit may be used directly from an application program by providing
-- an appropriate WITH, and the interface can be expected to remain stable.
-- This is the SGI (libathread) specific version of this module.
with System.OS_Interface;
package System.Task_Info is
pragma Elaborate_Body;
-- To ensure that a body is allowed
---------------------------------------------------------
-- Binding of Tasks to sprocs and sprocs to processors --
---------------------------------------------------------
-- The SGI implementation of the GNU Low-Level Interface (GNULLI)
-- implements each Ada task as a Posix thread (Pthread). The SGI
-- Pthread library distributes threads across one or more processes
-- that are members of a common share group. Irix distributes
-- processes across the available CPUs on a given machine. The
-- pragma Task_Info provides the mechanism to control the distribution
-- of tasks to sprocs, and sprocs to processors.
-- Each thread has a number of attributes that dictate it's scheduling.
-- These attributes are:
--
-- Bound_To_Sproc: whether the thread is bound to a specific sproc
-- for its entire lifetime.
--
-- Timeslice: Amount of time that a thread is allowed to execute
-- before the system yeilds control to another thread
-- of equal priority.
--
-- Resource_Vector: A bitmask used to control the binding of threads
-- to sprocs.
--
-- Each share group process (sproc)
-- The Task_Info pragma:
-- pragma Task_Info (EXPRESSION);
-- allows the specification on a task by task basis of a value of type
-- System.Task_Info.Task_Info_Type to be passed to a task when it is
-- created. The specification of this type, and the effect on the task
-- that is created is target dependent.
-- The Task_Info pragma appears within a task definition (compare the
-- definition and implementation of pragma Priority). If no such pragma
-- appears, then the value Task_Info_Unspecified is passed. If a pragma
-- is present, then it supplies an alternative value. If the argument of
-- the pragma is a discriminant reference, then the value can be set on
-- a task by task basis by supplying the appropriate discriminant value.
-- Note that this means that the type used for Task_Info_Type must be
-- suitable for use as a discriminant (i.e. a scalar or access type).
----------------------
-- Resource Vectors --
----------------------
-- <discussion>
type Resource_Vector_T is array (0 .. 31) of Boolean;
pragma Pack (Resource_Vector_T);
NO_RESOURCES : constant Resource_Vector_T := (others => False);
generic
type Resource_T is (<>);
-- Discrete type up to 32 entries
package Resource_Vector_Functions is
function "+"
(R : Resource_T)
return Resource_Vector_T;
function "+"
(R1 : Resource_T;
R2 : Resource_T)
return Resource_Vector_T;
function "+"
(R : Resource_T;
S : Resource_Vector_T)
return Resource_Vector_T;
function "+"
(S : Resource_Vector_T;
R : Resource_T)
return Resource_Vector_T;
function "+"
(S1 : Resource_Vector_T;
S2 : Resource_Vector_T)
return Resource_Vector_T;
function "-"
(S : Resource_Vector_T;
R : Resource_T)
return Resource_Vector_T;
end Resource_Vector_Functions;
----------------------
-- Sproc Attributes --
----------------------
subtype sproc_t is System.OS_Interface.sproc_t;
subtype CPU_Number is Integer range -1 .. Integer'Last;
ANY_CPU : constant CPU_Number := CPU_Number'First;
type Non_Degrading_Priority is range 0 .. 255;
-- Specification of IRIX Non Degrading Priorities.
--
-- WARNING: IRIX priorities have the reverse meaning of Ada priorities.
-- The lower the priority value, the greater the greater the
-- scheduling preference.
--
-- See the schedctl(2) man page for a complete discussion of non-degrading
-- priorities.
NDPHIMAX : constant Non_Degrading_Priority := 30;
NDPHIMIN : constant Non_Degrading_Priority := 39;
-- These priorities are higher than ALL normal user process priorities
subtype NDP_High is Non_Degrading_Priority range NDPHIMAX .. NDPHIMIN;
NDPNORMMAX : constant Non_Degrading_Priority := 40;
NDPNORMMIN : constant Non_Degrading_Priority := 127;
-- These priorities overlap normal user process priorities
subtype NDP_Norm is Non_Degrading_Priority range NDPNORMMAX .. NDPNORMMIN;
NDPLOMAX : constant Non_Degrading_Priority := 128;
NDPLOMIN : constant Non_Degrading_Priority := 254;
-- These priorities are below ALL normal user process priorities
NDP_NONE : constant Non_Degrading_Priority := 255;
subtype NDP_LOW is Non_Degrading_Priority range NDPLOMAX .. NDPLOMIN;
type Page_Locking is
(NOLOCK, -- Do not lock pages in memory
PROCLOCK, -- Lock text and data segments into memory (process lock)
TXTLOCK, -- Lock text segment into memory (text lock)
DATLOCK -- Lock data segment into memory (data lock)
);
type Sproc_Attributes is record
Sproc_Resources : Resource_Vector_T := NO_RESOURCES;
CPU : CPU_Number := ANY_CPU;
Resident : Page_Locking := NOLOCK;
NDPRI : Non_Degrading_Priority := NDP_NONE;
-- ??? why is that commented out, should it be removed ?
-- Sproc_Slice : Duration := 0.0;
-- Deadline_Period : Duration := 0.0;
-- Deadline_Alloc : Duration := 0.0;
end record;
Default_Sproc_Attributes : constant Sproc_Attributes :=
(NO_RESOURCES, ANY_CPU, NOLOCK, NDP_NONE);
function New_Sproc (Attr : Sproc_Attributes) return sproc_t;
function New_Sproc
(Sproc_Resources : Resource_Vector_T := NO_RESOURCES;
CPU : CPU_Number := ANY_CPU;
Resident : Page_Locking := NOLOCK;
NDPRI : Non_Degrading_Priority := NDP_NONE)
return sproc_t;
-- Allocates a sproc_t control structure and creates the
-- corresponding sproc.
Invalid_CPU_Number : exception;
Permission_Error : exception;
Sproc_Create_Error : exception;
-----------------------
-- Thread Attributes --
-----------------------
type Thread_Attributes (Bound_To_Sproc : Boolean) is record
Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0;
case Bound_To_Sproc is
when False =>
null;
when True =>
Sproc : sproc_t;
end case;
end record;
Default_Thread_Attributes : constant Thread_Attributes :=
(False, NO_RESOURCES, 0.0);
function Unbound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0)
return Thread_Attributes;
function Bound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0;
Sproc : sproc_t)
return Thread_Attributes;
function Bound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0;
Sproc_Resources : Resource_Vector_T := NO_RESOURCES;
CPU : CPU_Number := ANY_CPU;
Resident : Page_Locking := NOLOCK;
NDPRI : Non_Degrading_Priority := NDP_NONE)
return Thread_Attributes;
type Task_Info_Type is access all Thread_Attributes;
function New_Unbound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0)
return Task_Info_Type;
function New_Bound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0;
Sproc : sproc_t)
return Task_Info_Type;
function New_Bound_Thread_Attributes
(Thread_Resources : Resource_Vector_T := NO_RESOURCES;
Thread_Timeslice : Duration := 0.0;
Sproc_Resources : Resource_Vector_T := NO_RESOURCES;
CPU : CPU_Number := ANY_CPU;
Resident : Page_Locking := NOLOCK;
NDPRI : Non_Degrading_Priority := NDP_NONE)
return Task_Info_Type;
Unspecified_Task_Info : constant Task_Info_Type := null;
end System.Task_Info;
|
