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) 2001-2023, 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 3, or (at your option) any later ver- --
14 -- sion. GNAT 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 -- This is a VxWorks version of this package
34 with System
.OS_Interface
;
36 package System
.Task_Primitives
is
39 type Lock
is limited private;
40 -- Should be used for implementation of protected objects
42 type RTS_Lock
is limited private;
43 -- Should be used inside the runtime system. The difference between Lock
44 -- and the RTS_Lock is that the later one serves only as a semaphore so
45 -- that do not check for ceiling violations.
47 type Suspension_Object
is limited private;
48 -- Should be used for the implementation of Ada.Synchronous_Task_Control
50 type Task_Body_Access
is access procedure;
51 -- Pointer to the task body's entry point (or possibly a wrapper
52 -- declared local to the GNARL).
54 type Private_Data
is limited private;
55 -- Any information that the GNULLI needs maintained on a per-task basis.
56 -- A component of this type is guaranteed to be included in the
57 -- Ada_Task_Control_Block.
59 subtype Task_Address
is System
.Address
;
60 Task_Address_Size
: constant := Standard
'Address_Size;
61 -- Type used for task addresses and its size
63 Alternate_Stack_Size
: constant := 0;
64 -- No alternate signal stack is used on this platform
68 type Priority_Type
is (Prio_None
, Prio_Protect
, Prio_Inherit
);
71 Mutex
: System
.OS_Interface
.SEM_ID
;
72 Protocol
: Priority_Type
;
74 Prio_Ceiling
: System
.OS_Interface
.int
;
75 -- Priority ceiling of lock
78 type RTS_Lock
is new Lock
;
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
.SEM_ID
;
91 -- Protection for ensuring mutual exclusion on the Suspension_Object
93 CV
: aliased System
.OS_Interface
.SEM_ID
;
94 -- Condition variable used to queue threads until condition is signaled
97 type Private_Data
is limited record
98 Thread
: aliased System
.OS_Interface
.t_id
:= 0;
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 LWP
: aliased System
.OS_Interface
.t_id
:= 0;
107 -- The purpose of this field is to provide a better tasking support on
108 -- gdb. The order of the two first fields (Thread and LWP) is important.
109 -- On targets where lwp is not relevant, this is equivalent to Thread.
111 CV
: aliased System
.OS_Interface
.SEM_ID
;
113 L
: aliased RTS_Lock
;
114 -- Protection for all components is lock L
117 end System
.Task_Primitives
;