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 --
9 -- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
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 2, or (at your option) any later ver- --
14 -- sion. GNARL 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This is a Solaris version of this package
36 -- This package provides low-level support for most tasking features.
39 -- Turn off polling, we do not want ATC polling to take place during
40 -- tasking operations. It causes infinite loops and other problems.
42 with System.OS_Interface;
47 with Unchecked_Conversion;
49 package System.Task_Primitives is
52 type Lock is limited private;
53 type Lock_Ptr is access all Lock;
54 -- Should be used for implementation of protected objects
56 type RTS_Lock is limited private;
57 type RTS_Lock_Ptr is access all RTS_Lock;
58 -- Should be used inside the runtime system.
59 -- The difference between Lock and the RTS_Lock is that the later
60 -- one serves only as a semaphore so that do not check for
61 -- ceiling violations.
63 function To_Lock_Ptr is new Unchecked_Conversion (RTS_Lock_Ptr, Lock_Ptr);
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;
86 function To_Owner_ID is
87 new Unchecked_Conversion (System.Address, Owner_ID);
90 L : aliased Base_Lock;
91 Ceiling : System.Any_Priority := System.Any_Priority'First;
92 Saved_Priority : System.Any_Priority := System.Any_Priority'First;
95 Level : Private_Task_Serial_Number := 0;
97 Frozen : Boolean := False;
100 type RTS_Lock is new Lock;
102 -- Note that task support on gdb relies on the fact that the first
103 -- 2 fields of Private_Data are Thread and LWP.
105 type Private_Data is record
106 Thread : aliased System.OS_Interface.thread_t;
107 pragma Atomic (Thread);
108 -- Thread field may be updated by two different threads of control.
109 -- (See, Enter_Task and Create_Task in s-taprop.adb).
110 -- They put the same value (thr_self value). We do not want to
111 -- use lock on those operations and the only thing we have to
112 -- make sure is that they are updated in atomic fashion.
114 LWP : System.OS_Interface.lwpid_t;
115 -- The LWP id of the thread. Set by self in Enter_Task.
117 CV : aliased System.OS_Interface.cond_t;
118 L : aliased RTS_Lock;
119 -- Protection for all components is lock L
121 Active_Priority : System.Any_Priority := System.Any_Priority'First;
122 -- Simulated active priority,
123 -- used only if Priority_Ceiling_Support is True.
127 Wakeups : Natural := 0;
130 end System.Task_Primitives;