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) 1991-2017, Florida State University --
10 -- Copyright (C) 1995-2024, AdaCore --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 3, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. --
19 -- As a special exception under Section 7 of GPL version 3, you are granted --
20 -- additional permissions described in the GCC Runtime Library Exception, --
21 -- version 3.1, as published by the Free Software Foundation. --
23 -- You should have received a copy of the GNU General Public License and --
24 -- a copy of the GCC Runtime Library Exception along with this program; --
25 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
26 -- <http://www.gnu.org/licenses/>. --
28 -- GNARL was developed by the GNARL team at Florida State University. --
29 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
31 ------------------------------------------------------------------------------
33 -- This is a POSIX-like version of this package
35 -- Note: this file can only be used for POSIX compliant systems
37 with System
.OS_Interface
;
40 package System
.Task_Primitives
is
43 type Lock
is limited private;
44 -- Should be used for implementation of protected objects
46 type Suspension_Object
is limited private;
47 -- Should be used for the implementation of Ada.Synchronous_Task_Control
49 type Task_Body_Access
is access procedure;
50 -- Pointer to the task body's entry point (or possibly a wrapper declared
51 -- local to the GNARL).
53 type Private_Data
is limited private;
54 -- Any information that the GNULLI needs maintained on a per-task basis.
55 -- A component of this type is guaranteed to be included in the
56 -- Ada_Task_Control_Block.
58 subtype Task_Address
is System
.Address
;
59 Task_Address_Size
: constant := Standard
'Address_Size;
60 -- Type used for task addresses and its size
62 Alternate_Stack_Size
: constant := System
.OS_Interface
.Alternate_Stack_Size
;
63 -- Import value from System.OS_Interface
68 RW
: aliased System
.OS_Interface
.pthread_rwlock_t
;
69 WO
: aliased System
.OS_Locks
.RTS_Lock
;
72 type Suspension_Object
is record
74 pragma Atomic
(State
);
75 -- Boolean that indicates whether the object is open. This field is
76 -- marked Atomic to ensure that we can read its value without locking
77 -- the access to the Suspension_Object.
80 -- Flag showing if there is a task already suspended on this object
82 L
: aliased System
.OS_Locks
.RTS_Lock
;
83 -- Protection for ensuring mutual exclusion on the Suspension_Object
85 CV
: aliased System
.OS_Interface
.pthread_cond_t
;
86 -- Condition variable used to queue threads until condition is signaled
89 type Private_Data
is limited record
90 Thread
: aliased System
.OS_Interface
.pthread_t
;
91 -- This component is written to once before concurrent access to it is
92 -- possible, and then remains constant. The place where it is written to
93 -- depends on how the enclosing ATCB comes into existence:
95 -- 1. For the environment task, the component is set in
96 -- System.Task_Primitive.Operations.Initialize.
97 -- 2. For foreign threads, it happens in
98 -- System.Task_Primitives.Operations.Register_Foreign_Thread.
99 -- 3. For others tasks, it's in
100 -- System.Task_Primitives.Operations.Create_Task.
102 LWP
: aliased System
.Address
;
103 -- The purpose of this field is to provide a better tasking support on
104 -- gdb. The order of the two first fields (Thread and LWP) is important.
105 -- On targets where lwp is not relevant, this is equivalent to Thread.
107 CV
: aliased System
.OS_Interface
.pthread_cond_t
;
108 -- Condition variable used to queue threads until condition is signaled
110 L
: aliased System
.OS_Locks
.RTS_Lock
;
111 -- Protection for all components is lock L
114 end System
.Task_Primitives
;