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. --
31 -- Extensive contributions were provided by Ada Core Technologies Inc. --
33 ------------------------------------------------------------------------------
35 -- This is a Solaris version of this package.
36 -- It was created by hand for use with new "checked"
39 -- This package provides low-level support for most tasking features.
42 -- Turn off polling, we do not want ATC polling to take place during
43 -- tasking operations. It causes infinite loops and other problems.
45 with System.OS_Interface;
50 package System.Task_Primitives is
53 type Lock is limited private;
54 type Lock_Ptr is access all Lock;
55 -- Should be used for implementation of protected objects.
57 type RTS_Lock is limited private;
58 type RTS_Lock_Ptr is access all RTS_Lock;
59 -- Should be used inside the runtime system.
60 -- The difference between Lock and the RTS_Lock is that the later
61 -- one serves only as a semaphore so that do not check for
62 -- ceiling violations.
64 type Task_Body_Access is access procedure;
65 -- Pointer to the task body's entry point (or possibly a wrapper
66 -- declared local to the GNARL).
68 type Private_Data is limited private;
69 -- Any information that the GNULLI needs maintained on a per-task
70 -- basis. A component of this type is guaranteed to be included
71 -- in the Ada_Task_Control_Block.
75 type Private_Task_Serial_Number is mod 2 ** 64;
76 -- Used to give each task a unique serial number.
78 type Base_Lock is new System.OS_Interface.mutex_t;
80 type Owner_Int is new Integer;
81 for Owner_Int'Alignment use Standard'Maximum_Alignment;
83 type Owner_ID is access all Owner_Int;
86 L : aliased Base_Lock;
87 Ceiling : System.Any_Priority := System.Any_Priority'First;
88 Saved_Priority : System.Any_Priority := System.Any_Priority'First;
91 Level : Private_Task_Serial_Number := 0;
93 Frozen : Boolean := False;
96 type RTS_Lock is new Lock;
98 -- Note that task support on gdb relies on the fact that the first
99 -- 2 fields of Private_Data are Thread and LWP.
101 type Private_Data is record
102 Thread : aliased System.OS_Interface.thread_t;
103 pragma Atomic (Thread);
104 -- Thread field may be updated by two different threads of control.
105 -- (See, Enter_Task and Create_Task in s-taprop.adb).
106 -- They put the same value (thr_self value). We do not want to
107 -- use lock on those operations and the only thing we have to
108 -- make sure is that they are updated in atomic fashion.
110 LWP : System.OS_Interface.lwpid_t;
111 -- The LWP id of the thread. Set by self in Enter_Task.
113 CV : aliased System.OS_Interface.cond_t;
114 L : aliased RTS_Lock;
115 -- protection for all components is lock L
117 Active_Priority : System.Any_Priority := System.Any_Priority'First;
118 -- Simulated active priority,
119 -- used only if Priority_Ceiling_Support is True.
123 Wakeups : Natural := 0;
126 end System.Task_Primitives;