1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S --
10 -- Copyright (C) 1992-2000, Free Software Foundation, Inc. --
12 -- GNARL is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNARL; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNARL was developed by the GNARL team at Florida State University. It is --
31 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
32 -- State University (http://www.gnat.com). --
34 ------------------------------------------------------------------------------
36 -- This is a Solaris version of this package.
37 -- It was created by hand for use with new "checked"
40 -- This package provides low-level support for most tasking features.
43 -- Turn off polling, we do not want ATC polling to take place during
44 -- tasking operations. It causes infinite loops and other problems.
46 with System
.OS_Interface
;
51 package System
.Task_Primitives
is
54 type Lock
is limited private;
55 type Lock_Ptr
is access all Lock
;
56 -- Should be used for implementation of protected objects.
58 type RTS_Lock
is limited private;
59 type RTS_Lock_Ptr
is access all RTS_Lock
;
60 -- Should be used inside the runtime system.
61 -- The difference between Lock and the RTS_Lock is that the later
62 -- one serves only as a semaphore so that do not check for
63 -- ceiling violations.
65 type Task_Body_Access
is access procedure;
66 -- Pointer to the task body's entry point (or possibly a wrapper
67 -- declared local to the GNARL).
69 type Private_Data
is limited private;
70 -- Any information that the GNULLI needs maintained on a per-task
71 -- basis. A component of this type is guaranteed to be included
72 -- in the Ada_Task_Control_Block.
76 type Private_Task_Serial_Number
is mod 2 ** 64;
77 -- Used to give each task a unique serial number.
79 type Base_Lock
is new System
.OS_Interface
.mutex_t
;
81 type Owner_Int
is new Integer;
82 for Owner_Int
'Alignment use Standard
'Maximum_Alignment;
84 type Owner_ID
is access all Owner_Int
;
87 L
: aliased Base_Lock
;
88 Ceiling
: System
.Any_Priority
:= System
.Any_Priority
'First;
89 Saved_Priority
: System
.Any_Priority
:= System
.Any_Priority
'First;
92 Level
: Private_Task_Serial_Number
:= 0;
94 Frozen
: Boolean := False;
97 type RTS_Lock
is new Lock
;
99 -- Note that task support on gdb relies on the fact that the first
100 -- 2 fields of Private_Data are Thread and LWP.
102 type Private_Data
is record
103 Thread
: aliased System
.OS_Interface
.thread_t
;
104 pragma Atomic
(Thread
);
105 -- Thread field may be updated by two different threads of control.
106 -- (See, Enter_Task and Create_Task in s-taprop.adb).
107 -- They put the same value (thr_self value). We do not want to
108 -- use lock on those operations and the only thing we have to
109 -- make sure is that they are updated in atomic fashion.
111 LWP
: System
.OS_Interface
.lwpid_t
;
112 -- The LWP id of the thread. Set by self in Enter_Task.
114 CV
: aliased System
.OS_Interface
.cond_t
;
115 L
: aliased RTS_Lock
;
116 -- protection for all components is lock L
118 Active_Priority
: System
.Any_Priority
:= System
.Any_Priority
'First;
119 -- Simulated active priority,
120 -- used only if Priority_Ceiling_Support is True.
124 Wakeups
: Natural := 0;
127 end System
.Task_Primitives
;