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 --
11 -- Copyright (C) 1992-2000, Free Software Foundation, Inc. --
13 -- GNARL is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNARL; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
31 -- GNARL was developed by the GNARL team at Florida State University. It is --
32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
33 -- State University (http://www.gnat.com). --
35 ------------------------------------------------------------------------------
37 -- This is a Solaris version of this package.
38 -- It was created by hand for use with new "checked"
41 -- This package provides low-level support for most tasking features.
44 -- Turn off polling, we do not want ATC polling to take place during
45 -- tasking operations. It causes infinite loops and other problems.
47 with System
.OS_Interface
;
52 package System
.Task_Primitives
is
55 type Lock
is limited private;
56 type Lock_Ptr
is access all Lock
;
57 -- Should be used for implementation of protected objects.
59 type RTS_Lock
is limited private;
60 type RTS_Lock_Ptr
is access all RTS_Lock
;
61 -- Should be used inside the runtime system.
62 -- The difference between Lock and the RTS_Lock is that the later
63 -- one serves only as a semaphore so that do not check for
64 -- ceiling violations.
66 type Task_Body_Access
is access procedure;
67 -- Pointer to the task body's entry point (or possibly a wrapper
68 -- declared local to the GNARL).
70 type Private_Data
is limited private;
71 -- Any information that the GNULLI needs maintained on a per-task
72 -- basis. A component of this type is guaranteed to be included
73 -- in the Ada_Task_Control_Block.
77 type Private_Task_Serial_Number
is mod 2 ** 64;
78 -- Used to give each task a unique serial number.
80 type Base_Lock
is new System
.OS_Interface
.mutex_t
;
82 type Owner_Int
is new Integer;
83 for Owner_Int
'Alignment use Standard
'Maximum_Alignment;
85 type Owner_ID
is access all Owner_Int
;
88 L
: aliased Base_Lock
;
89 Ceiling
: System
.Any_Priority
:= System
.Any_Priority
'First;
90 Saved_Priority
: System
.Any_Priority
:= System
.Any_Priority
'First;
93 Level
: Private_Task_Serial_Number
:= 0;
95 Frozen
: Boolean := False;
98 type RTS_Lock
is new Lock
;
100 -- Note that task support on gdb relies on the fact that the first
101 -- 2 fields of Private_Data are Thread and LWP.
103 type Private_Data
is record
104 Thread
: aliased System
.OS_Interface
.thread_t
;
105 pragma Atomic
(Thread
);
106 -- Thread field may be updated by two different threads of control.
107 -- (See, Enter_Task and Create_Task in s-taprop.adb).
108 -- They put the same value (thr_self value). We do not want to
109 -- use lock on those operations and the only thing we have to
110 -- make sure is that they are updated in atomic fashion.
112 LWP
: System
.OS_Interface
.lwpid_t
;
113 -- The LWP id of the thread. Set by self in Enter_Task.
115 CV
: aliased System
.OS_Interface
.cond_t
;
116 L
: aliased RTS_Lock
;
117 -- protection for all components is lock L
119 Active_Priority
: System
.Any_Priority
:= System
.Any_Priority
'First;
120 -- Simulated active priority,
121 -- used only if Priority_Ceiling_Support is True.
125 Wakeups
: Natural := 0;
128 end System
.Task_Primitives
;