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) 1991-2008, 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 tasking
38 -- operations. It causes infinite loops and other problems.
40 with System
.OS_Interface
;
43 package System
.Task_Primitives
is
46 type Lock
is limited private;
47 -- Should be used for implementation of protected objects
49 type RTS_Lock
is limited private;
50 -- Should be used inside the runtime system. The difference between Lock
51 -- and the RTS_Lock is that the later one serves only as a semaphore so
52 -- that do not check for ceiling violations.
54 type Suspension_Object
is limited private;
55 -- Should be used for the implementation of Ada.Synchronous_Task_Control
57 type Task_Body_Access
is access procedure;
58 -- Pointer to the task body's entry point (or possibly a wrapper
59 -- declared local to the GNARL).
61 type Private_Data
is limited private;
62 -- Any information that the GNULLI needs maintained on a per-task basis.
63 -- A component of this type is guaranteed to be included in the
64 -- Ada_Task_Control_Block.
66 subtype Task_Address
is System
.Address
;
67 -- In some versions of Task_Primitives, notably for VMS, Task_Address is
68 -- the short version of address defined in System.Aux_DEC. To avoid
69 -- dragging Aux_DEC into tasking packages a tasking specific subtype is
72 Task_Address_Size
: constant := Standard
'Address_Size;
73 -- The size of Task_Address
75 Alternate_Stack_Size
: constant := 0;
76 -- No alternate signal stack is used on this platform
81 Mutex
: aliased System
.OS_Interface
.CRITICAL_SECTION
;
83 Owner_Priority
: Integer;
86 type Condition_Variable
is new System
.Win32
.HANDLE
;
88 type RTS_Lock
is new System
.OS_Interface
.CRITICAL_SECTION
;
90 type Suspension_Object
is record
92 pragma Atomic
(State
);
93 -- Boolean that indicates whether the object is open. This field is
94 -- marked Atomic to ensure that we can read its value without locking
95 -- the access to the Suspension_Object.
98 -- Flag showing if there is a task already suspended on this object
100 L
: aliased System
.OS_Interface
.CRITICAL_SECTION
;
101 -- Protection for ensuring mutual exclusion on the Suspension_Object
103 CV
: aliased Win32
.HANDLE
;
104 -- Condition variable used to queue threads until condition is signaled
107 type Private_Data
is record
108 Thread
: aliased Win32
.HANDLE
;
109 pragma Atomic
(Thread
);
110 -- Thread field may be updated by two different threads of control.
111 -- (See, Enter_Task and Create_Task in s-taprop.adb).
112 -- They put the same value (thr_self value). We do not want to
113 -- use lock on those operations and the only thing we have to
114 -- make sure is that they are updated in atomic fashion.
116 Thread_Id
: aliased Win32
.DWORD
;
117 -- Used to provide a better tasking support in gdb
119 CV
: aliased Condition_Variable
;
120 -- Condition Variable used to implement Sleep/Wakeup
122 L
: aliased RTS_Lock
;
123 -- Protection for all components is lock L
126 end System
.Task_Primitives
;