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) 1995-2023, 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 where no alternate stack
34 -- is needed for stack checking.
36 -- Note: this file can only be used for POSIX compliant systems
38 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 RTS_Lock
is limited private;
47 -- Should be used inside the runtime system. The difference between Lock
48 -- and the RTS_Lock is that the later one serves only as a semaphore so
49 -- that do not check for ceiling violations.
51 type Suspension_Object
is limited private;
52 -- Should be used for the implementation of Ada.Synchronous_Task_Control
54 type Task_Body_Access
is access procedure;
55 -- Pointer to the task body's entry point (or possibly a wrapper declared
56 -- local to the GNARL).
58 type Private_Data
is limited private;
59 -- Any information that the GNULLI needs maintained on a per-task basis.
60 -- A component of this type is guaranteed to be included in the
61 -- Ada_Task_Control_Block.
63 subtype Task_Address
is System
.Address
;
64 Task_Address_Size
: constant := Standard
'Address_Size;
65 -- Type used for task addresses and its size
67 Alternate_Stack_Size
: constant := 0;
68 -- No alternate signal stack is used on this platform
72 type RTS_Lock
is new System
.OS_Interface
.pthread_mutex_t
;
75 WO
: aliased RTS_Lock
;
76 RW
: aliased System
.OS_Interface
.pthread_rwlock_t
;
79 type Suspension_Object
is record
81 pragma Atomic
(State
);
82 -- Boolean that indicates whether the object is open. This field is
83 -- marked Atomic to ensure that we can read its value without locking
84 -- the access to the Suspension_Object.
87 -- Flag showing if there is a task already suspended on this object
90 -- Protection for ensuring mutual exclusion on the Suspension_Object
92 CV
: aliased System
.OS_Interface
.pthread_cond_t
;
93 -- Condition variable used to queue threads until condition is signaled
96 type Private_Data
is limited record
97 Thread
: aliased System
.OS_Interface
.pthread_t
;
98 pragma Atomic
(Thread
);
99 -- Thread field may be updated by two different threads of control.
100 -- (See, Enter_Task and Create_Task in s-taprop.adb). They put the same
101 -- value (thr_self value). We do not want to use lock on those
102 -- operations and the only thing we have to make sure is that they are
103 -- updated in atomic fashion.
105 LWP
: aliased System
.Address
;
106 -- The purpose of this field is to provide a better tasking support on
107 -- gdb. The order of the two first fields (Thread and LWP) is important.
108 -- On targets where lwp is not relevant, this is equivalent to Thread.
110 CV
: aliased System
.OS_Interface
.pthread_cond_t
;
111 -- Should be commented ??? (in all versions of taspri)
113 L
: aliased RTS_Lock
;
114 -- Protection for all components is lock L
117 end System
.Task_Primitives
;