File : s-solita.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S Y S T E M . S O F T _ L I N K S . T A S K I N G --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2004-2015, 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 pragma Style_Checks (All_Checks);
33 -- Turn off subprogram alpha ordering check, since we group soft link bodies
34 -- and dummy soft link bodies together separately in this unit.
35
36 pragma Polling (Off);
37 -- Turn polling off for this package. We don't need polling during any of the
38 -- routines in this package, and more to the point, if we try to poll it can
39 -- cause infinite loops.
40
41 with Ada.Exceptions;
42 with Ada.Exceptions.Is_Null_Occurrence;
43
44 with System.Task_Primitives.Operations;
45 with System.Tasking;
46 with System.Stack_Checking;
47
48 package body System.Soft_Links.Tasking is
49
50 package STPO renames System.Task_Primitives.Operations;
51 package SSL renames System.Soft_Links;
52
53 use Ada.Exceptions;
54
55 use type System.Tasking.Task_Id;
56 use type System.Tasking.Termination_Handler;
57
58 ----------------
59 -- Local Data --
60 ----------------
61
62 Initialized : Boolean := False;
63 -- Boolean flag that indicates whether the tasking soft links have
64 -- already been set.
65
66 -----------------------------------------------------------------
67 -- Tasking Versions of Services Needed by Non-Tasking Programs --
68 -----------------------------------------------------------------
69
70 function Get_Jmpbuf_Address return Address;
71 procedure Set_Jmpbuf_Address (Addr : Address);
72 -- Get/Set Jmpbuf_Address for current task
73
74 function Get_Sec_Stack_Addr return Address;
75 procedure Set_Sec_Stack_Addr (Addr : Address);
76 -- Get/Set location of current task's secondary stack
77
78 procedure Timed_Delay_T (Time : Duration; Mode : Integer);
79 -- Task-safe version of SSL.Timed_Delay
80
81 procedure Task_Termination_Handler_T (Excep : SSL.EO);
82 -- Task-safe version of the task termination procedure
83
84 function Get_Stack_Info return Stack_Checking.Stack_Access;
85 -- Get access to the current task's Stack_Info
86
87 --------------------------
88 -- Soft-Link Get Bodies --
89 --------------------------
90
91 function Get_Jmpbuf_Address return Address is
92 begin
93 return STPO.Self.Common.Compiler_Data.Jmpbuf_Address;
94 end Get_Jmpbuf_Address;
95
96 function Get_Sec_Stack_Addr return Address is
97 begin
98 return Result : constant Address :=
99 STPO.Self.Common.Compiler_Data.Sec_Stack_Addr
100 do
101 pragma Assert (Result /= Null_Address);
102 end return;
103 end Get_Sec_Stack_Addr;
104
105 function Get_Stack_Info return Stack_Checking.Stack_Access is
106 begin
107 return STPO.Self.Common.Compiler_Data.Pri_Stack_Info'Access;
108 end Get_Stack_Info;
109
110 --------------------------
111 -- Soft-Link Set Bodies --
112 --------------------------
113
114 procedure Set_Jmpbuf_Address (Addr : Address) is
115 begin
116 STPO.Self.Common.Compiler_Data.Jmpbuf_Address := Addr;
117 end Set_Jmpbuf_Address;
118
119 procedure Set_Sec_Stack_Addr (Addr : Address) is
120 begin
121 STPO.Self.Common.Compiler_Data.Sec_Stack_Addr := Addr;
122 end Set_Sec_Stack_Addr;
123
124 -------------------
125 -- Timed_Delay_T --
126 -------------------
127
128 procedure Timed_Delay_T (Time : Duration; Mode : Integer) is
129 Self_Id : constant System.Tasking.Task_Id := STPO.Self;
130
131 begin
132 -- In case pragma Detect_Blocking is active then Program_Error
133 -- must be raised if this potentially blocking operation
134 -- is called from a protected operation.
135
136 if System.Tasking.Detect_Blocking
137 and then Self_Id.Common.Protected_Action_Nesting > 0
138 then
139 raise Program_Error with "potentially blocking operation";
140 else
141 Abort_Defer.all;
142 STPO.Timed_Delay (Self_Id, Time, Mode);
143 Abort_Undefer.all;
144 end if;
145 end Timed_Delay_T;
146
147 --------------------------------
148 -- Task_Termination_Handler_T --
149 --------------------------------
150
151 procedure Task_Termination_Handler_T (Excep : SSL.EO) is
152 Self_Id : constant System.Tasking.Task_Id := STPO.Self;
153 Cause : System.Tasking.Cause_Of_Termination;
154 EO : Ada.Exceptions.Exception_Occurrence;
155
156 begin
157 -- We can only be here because we are terminating the environment task.
158 -- Task termination for all other tasks is handled in the Task_Wrapper.
159
160 -- We do not want to enable this check and e.g. call System.OS_Lib.Abort
161 -- here because some restricted run-times may not have System.OS_Lib
162 -- and calling abort may do more harm than good to the main application.
163
164 pragma Assert (Self_Id = STPO.Environment_Task);
165
166 -- Normal task termination
167
168 if Is_Null_Occurrence (Excep) then
169 Cause := System.Tasking.Normal;
170 Ada.Exceptions.Save_Occurrence (EO, Ada.Exceptions.Null_Occurrence);
171
172 -- Abnormal task termination
173
174 elsif Exception_Identity (Excep) = Standard'Abort_Signal'Identity then
175 Cause := System.Tasking.Abnormal;
176 Ada.Exceptions.Save_Occurrence (EO, Ada.Exceptions.Null_Occurrence);
177
178 -- Termination because of an unhandled exception
179
180 else
181 Cause := System.Tasking.Unhandled_Exception;
182 Ada.Exceptions.Save_Occurrence (EO, Excep);
183 end if;
184
185 -- There is no need for explicit protection against race conditions for
186 -- this part because it can only be executed by the environment task
187 -- after all the other tasks have been finalized. Note that there is no
188 -- fall-back handler which could apply to this environment task because
189 -- it has no parents, and, as specified in ARM C.7.3 par. 9/2, "the
190 -- fall-back handler applies only to the dependent tasks of the task".
191
192 if Self_Id.Common.Specific_Handler /= null then
193 Self_Id.Common.Specific_Handler.all (Cause, Self_Id, EO);
194 end if;
195 end Task_Termination_Handler_T;
196
197 -----------------------------
198 -- Init_Tasking_Soft_Links --
199 -----------------------------
200
201 procedure Init_Tasking_Soft_Links is
202 begin
203 -- Set links only if not set already
204
205 if not Initialized then
206
207 -- Mark tasking soft links as initialized
208
209 Initialized := True;
210
211 -- The application being executed uses tasking so that the tasking
212 -- version of the following soft links need to be used.
213
214 SSL.Get_Jmpbuf_Address := Get_Jmpbuf_Address'Access;
215 SSL.Set_Jmpbuf_Address := Set_Jmpbuf_Address'Access;
216 SSL.Get_Sec_Stack_Addr := Get_Sec_Stack_Addr'Access;
217 SSL.Get_Stack_Info := Get_Stack_Info'Access;
218 SSL.Set_Sec_Stack_Addr := Set_Sec_Stack_Addr'Access;
219 SSL.Timed_Delay := Timed_Delay_T'Access;
220 SSL.Task_Termination_Handler := Task_Termination_Handler_T'Access;
221
222 -- No need to create a new secondary stack, since we will use the
223 -- default one created in s-secsta.adb.
224
225 SSL.Set_Sec_Stack_Addr (SSL.Get_Sec_Stack_Addr_NT);
226 SSL.Set_Jmpbuf_Address (SSL.Get_Jmpbuf_Address_NT);
227 end if;
228
229 pragma Assert (Get_Sec_Stack_Addr /= Null_Address);
230 end Init_Tasking_Soft_Links;
231
232 end System.Soft_Links.Tasking;