1 ------------------------------------------------------------------------------
3 -- GNAT 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) 1991-2005 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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 NT (native) version of this package
37 -- Turn off polling, we do not want ATC polling to take place during
38 -- tasking operations. It causes infinite loops and other problems.
40 with System
.OS_Interface
;
41 -- used for pthread_mutex_t
45 package System
.Task_Primitives
is
48 type Lock
is limited private;
49 -- Should be used for implementation of protected objects
51 type RTS_Lock
is limited private;
52 -- Should be used inside the runtime system. The difference between Lock
53 -- and the RTS_Lock is that the later one serves only as a semaphore so
54 -- that do not check for ceiling violations.
56 type Suspension_Object
is limited private;
57 -- Should be used for the implementation of Ada.Synchronous_Task_Control
59 type Task_Body_Access
is access procedure;
60 -- Pointer to the task body's entry point (or possibly a wrapper
61 -- declared local to the GNARL).
63 type Private_Data
is limited private;
64 -- Any information that the GNULLI needs maintained on a per-task basis.
65 -- A component of this type is guaranteed to be included in the
66 -- Ada_Task_Control_Block.
71 Mutex
: aliased System
.OS_Interface
.CRITICAL_SECTION
;
73 Owner_Priority
: Integer;
76 type Condition_Variable
is new System
.OS_Interface
.HANDLE
;
78 type RTS_Lock
is new System
.OS_Interface
.CRITICAL_SECTION
;
80 type Suspension_Object
is record
82 pragma Atomic
(State
);
83 -- Boolean that indicates whether the object is open. This field is
84 -- marked Atomic to ensure that we can read its value without locking
85 -- the access to the Suspension_Object.
88 -- Flag showing if there is a task already suspended on this object
90 L
: aliased System
.OS_Interface
.CRITICAL_SECTION
;
91 -- Protection for ensuring mutual exclusion on the Suspension_Object
93 CV
: aliased System
.OS_Interface
.HANDLE
;
94 -- Condition variable used to queue threads until condition is signaled
97 type Private_Data
is record
98 Thread
: aliased System
.OS_Interface
.HANDLE
;
99 pragma Atomic
(Thread
);
100 -- Thread field may be updated by two different threads of control.
101 -- (See, Enter_Task and Create_Task in s-taprop.adb).
102 -- They put the same value (thr_self value). We do not want to
103 -- use lock on those operations and the only thing we have to
104 -- make sure is that they are updated in atomic fashion.
106 Thread_Id
: aliased System
.OS_Interface
.DWORD
;
107 -- Used to provide a better tasking support in gdb
109 CV
: aliased Condition_Variable
;
110 -- Condition Variable used to implement Sleep/Wakeup
112 L
: aliased RTS_Lock
;
113 -- Protection for all components is lock L
116 end System
.Task_Primitives
;