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comparison gcc/ada/libgnarl/s-taskin.adb @ 111:04ced10e8804

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gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
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children 84e7813d76e9
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68:561a7518be6b 111:04ced10e8804
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- S Y S T E M . T A S K I N G --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2017, Free Software Foundation, Inc. --
10 -- --
11 -- GNARL 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 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
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 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 pragma Polling (Off);
33 -- Turn off polling, we do not want ATC polling to take place during tasking
34 -- operations. It causes infinite loops and other problems.
35
36 with System.Task_Primitives.Operations;
37 with System.Storage_Elements;
38
39 package body System.Tasking is
40
41 package STPO renames System.Task_Primitives.Operations;
42
43 ---------------------
44 -- Detect_Blocking --
45 ---------------------
46
47 function Detect_Blocking return Boolean is
48 GL_Detect_Blocking : Integer;
49 pragma Import (C, GL_Detect_Blocking, "__gl_detect_blocking");
50 -- Global variable exported by the binder generated file. A value equal
51 -- to 1 indicates that pragma Detect_Blocking is active, while 0 is used
52 -- for the pragma not being present.
53
54 begin
55 return GL_Detect_Blocking = 1;
56 end Detect_Blocking;
57
58 -----------------------
59 -- Number_Of_Entries --
60 -----------------------
61
62 function Number_Of_Entries (Self_Id : Task_Id) return Entry_Index is
63 begin
64 return Entry_Index (Self_Id.Entry_Num);
65 end Number_Of_Entries;
66
67 ----------
68 -- Self --
69 ----------
70
71 function Self return Task_Id renames STPO.Self;
72
73 ------------------
74 -- Storage_Size --
75 ------------------
76
77 function Storage_Size (T : Task_Id) return System.Parameters.Size_Type is
78 begin
79 return
80 System.Parameters.Size_Type
81 (T.Common.Compiler_Data.Pri_Stack_Info.Size);
82 end Storage_Size;
83
84 ---------------------
85 -- Initialize_ATCB --
86 ---------------------
87
88 procedure Initialize_ATCB
89 (Self_ID : Task_Id;
90 Task_Entry_Point : Task_Procedure_Access;
91 Task_Arg : System.Address;
92 Parent : Task_Id;
93 Elaborated : Access_Boolean;
94 Base_Priority : System.Any_Priority;
95 Base_CPU : System.Multiprocessors.CPU_Range;
96 Domain : Dispatching_Domain_Access;
97 Task_Info : System.Task_Info.Task_Info_Type;
98 Stack_Size : System.Parameters.Size_Type;
99 T : Task_Id;
100 Success : out Boolean)
101 is
102 begin
103 T.Common.State := Unactivated;
104
105 -- Initialize T.Common.LL
106
107 STPO.Initialize_TCB (T, Success);
108
109 if not Success then
110 return;
111 end if;
112
113 -- Note that use of an aggregate here for this assignment
114 -- would be illegal, because Common_ATCB is limited because
115 -- Task_Primitives.Private_Data is limited.
116
117 T.Common.Parent := Parent;
118 T.Common.Base_Priority := Base_Priority;
119 T.Common.Base_CPU := Base_CPU;
120
121 -- The Domain defaults to that of the activator. But that can be null in
122 -- the case of foreign threads (see Register_Foreign_Thread), in which
123 -- case we default to the System_Domain.
124
125 if Domain /= null then
126 T.Common.Domain := Domain;
127 elsif Self_ID.Common.Domain /= null then
128 T.Common.Domain := Self_ID.Common.Domain;
129 else
130 T.Common.Domain := System_Domain;
131 end if;
132 pragma Assert (T.Common.Domain /= null);
133
134 T.Common.Current_Priority := 0;
135 T.Common.Protected_Action_Nesting := 0;
136 T.Common.Call := null;
137 T.Common.Task_Arg := Task_Arg;
138 T.Common.Task_Entry_Point := Task_Entry_Point;
139 T.Common.Activator := Self_ID;
140 T.Common.Wait_Count := 0;
141 T.Common.Elaborated := Elaborated;
142 T.Common.Activation_Failed := False;
143 T.Common.Task_Info := Task_Info;
144 T.Common.Global_Task_Lock_Nesting := 0;
145 T.Common.Fall_Back_Handler := null;
146 T.Common.Specific_Handler := null;
147 T.Common.Debug_Events := (others => False);
148 T.Common.Task_Image_Len := 0;
149
150 if T.Common.Parent = null then
151
152 -- For the environment task, the adjusted stack size is meaningless.
153 -- For example, an unspecified Stack_Size means that the stack size
154 -- is determined by the environment, or can grow dynamically. The
155 -- Stack_Checking algorithm therefore needs to use the requested
156 -- size, or 0 in case of an unknown size.
157
158 T.Common.Compiler_Data.Pri_Stack_Info.Size :=
159 Storage_Elements.Storage_Offset (Stack_Size);
160
161 else
162 T.Common.Compiler_Data.Pri_Stack_Info.Size :=
163 Storage_Elements.Storage_Offset
164 (Parameters.Adjust_Storage_Size (Stack_Size));
165 end if;
166
167 -- Link the task into the list of all tasks
168
169 T.Common.All_Tasks_Link := All_Tasks_List;
170 All_Tasks_List := T;
171 end Initialize_ATCB;
172
173 ----------------
174 -- Initialize --
175 ----------------
176
177 Main_Task_Image : constant String := "main_task";
178 -- Image of environment task
179
180 Main_Priority : Integer;
181 pragma Import (C, Main_Priority, "__gl_main_priority");
182 -- Priority for main task. Note that this is of type Integer, not Priority,
183 -- because we use the value -1 to indicate the default main priority, and
184 -- that is of course not in Priority'range.
185
186 Main_CPU : Integer;
187 pragma Import (C, Main_CPU, "__gl_main_cpu");
188 -- Affinity for main task. Note that this is of type Integer, not
189 -- CPU_Range, because we use the value -1 to indicate the unassigned
190 -- affinity, and that is of course not in CPU_Range'Range.
191
192 Initialized : Boolean := False;
193 -- Used to prevent multiple calls to Initialize
194
195 procedure Initialize is
196 T : Task_Id;
197 Base_Priority : Any_Priority;
198 Base_CPU : System.Multiprocessors.CPU_Range;
199 Success : Boolean;
200
201 use type System.Multiprocessors.CPU_Range;
202
203 begin
204 if Initialized then
205 return;
206 end if;
207
208 Initialized := True;
209
210 -- Initialize Environment Task
211
212 Base_Priority :=
213 (if Main_Priority = Unspecified_Priority
214 then Default_Priority
215 else Priority (Main_Priority));
216
217 Base_CPU :=
218 (if Main_CPU = Unspecified_CPU
219 then System.Multiprocessors.Not_A_Specific_CPU
220 else System.Multiprocessors.CPU_Range (Main_CPU));
221
222 -- At program start-up the environment task is allocated to the default
223 -- system dispatching domain.
224 -- Make sure that the processors which are not available are not taken
225 -- into account. Use Number_Of_CPUs to know the exact number of
226 -- processors in the system at execution time.
227
228 System_Domain :=
229 new Dispatching_Domain'
230 (Multiprocessors.CPU'First .. Multiprocessors.Number_Of_CPUs =>
231 True);
232
233 T := STPO.New_ATCB (0);
234 Initialize_ATCB
235 (Self_ID => null,
236 Task_Entry_Point => null,
237 Task_Arg => Null_Address,
238 Parent => Null_Task,
239 Elaborated => null,
240 Base_Priority => Base_Priority,
241 Base_CPU => Base_CPU,
242 Domain => System_Domain,
243 Task_Info => Task_Info.Unspecified_Task_Info,
244 Stack_Size => 0,
245 T => T,
246 Success => Success);
247 pragma Assert (Success);
248
249 STPO.Initialize (T);
250 STPO.Set_Priority (T, T.Common.Base_Priority);
251 T.Common.State := Runnable;
252 T.Common.Task_Image_Len := Main_Task_Image'Length;
253 T.Common.Task_Image (Main_Task_Image'Range) := Main_Task_Image;
254
255 Dispatching_Domain_Tasks :=
256 new Array_Allocated_Tasks'
257 (Multiprocessors.CPU'First .. Multiprocessors.Number_Of_CPUs => 0);
258
259 -- Signal that this task is being allocated to a processor
260
261 if Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU then
262
263 -- Increase the number of tasks attached to the CPU to which this
264 -- task is allocated.
265
266 Dispatching_Domain_Tasks (Base_CPU) :=
267 Dispatching_Domain_Tasks (Base_CPU) + 1;
268 end if;
269
270 -- Only initialize the first element since others are not relevant
271 -- in ravenscar mode. Rest of the initialization is done in Init_RTS.
272
273 T.Entry_Calls (1).Self := T;
274 end Initialize;
275 end System.Tasking;