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) 1991-2000 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 OpenVMS/Alpha 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.
46 with System.OS_Interface;
47 -- used for pthread_mutex_t
51 package System.Task_Primitives is
53 type Lock is limited private;
54 -- Should be used for implementation of protected objects.
56 type RTS_Lock is limited private;
57 -- Should be used inside the runtime system.
58 -- The difference between Lock and the RTS_Lock is that the later
59 -- one serves only as a semaphore so that do not check for
60 -- ceiling violations.
62 type Task_Body_Access is access procedure;
63 -- Pointer to the task body's entry point (or possibly a wrapper
64 -- declared local to the GNARL).
66 type Private_Data is limited private;
67 -- Any information that the GNULLI needs maintained on a per-task
68 -- basis. A component of this type is guaranteed to be included
69 -- in the Ada_Task_Control_Block.
73 type Exc_Stack_T is array (0 .. 8192) of aliased Character;
74 for Exc_Stack_T'Alignment use Standard'Maximum_Alignment;
75 type Exc_Stack_Ptr_T is access all Exc_Stack_T;
78 L : aliased System.OS_Interface.pthread_mutex_t;
79 Prio : Interfaces.C.int;
80 Prio_Save : Interfaces.C.int;
83 type RTS_Lock is new System.OS_Interface.pthread_mutex_t;
84 type Private_Data is record
85 Thread : aliased System.OS_Interface.pthread_t;
86 pragma Atomic (Thread);
87 -- Thread field may be updated by two different threads of control.
88 -- (See, Enter_Task and Create_Task in s-taprop.adb).
89 -- They put the same value (thr_self value). We do not want to
90 -- use lock on those operations and the only thing we have to
91 -- make sure is that they are updated in atomic fashion.
93 CV : aliased System.OS_Interface.pthread_cond_t;
95 -- protection for all components is lock L
97 Exc_Stack_Ptr : Exc_Stack_Ptr_T;
98 -- ??? This needs comments.
100 AST_Pending : Boolean;
101 -- Used to detect delay and sleep timeouts
105 end System.Task_Primitives;