File : s-taspri-solaris.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
10 -- --
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. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
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/>. --
26 -- --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This is a Solaris version of this package
33
34 -- This package provides low-level support for most tasking features
35
36 pragma Polling (Off);
37 -- Turn off polling, we do not want ATC polling to take place during tasking
38 -- operations. It causes infinite loops and other problems.
39
40 with Ada.Unchecked_Conversion;
41
42 with System.OS_Interface;
43
44 package System.Task_Primitives is
45 pragma Preelaborate;
46
47 type Lock is limited private;
48 type Lock_Ptr is access all Lock;
49 -- Should be used for implementation of protected objects
50
51 type RTS_Lock is limited private;
52 type RTS_Lock_Ptr is access all RTS_Lock;
53 -- Should be used inside the runtime system. The difference between Lock
54 -- and the RTS_Lock is that the later one serves only as a semaphore so
55 -- that do not check for ceiling violations.
56
57 function To_Lock_Ptr is
58 new Ada.Unchecked_Conversion (RTS_Lock_Ptr, Lock_Ptr);
59
60 type Suspension_Object is limited private;
61 -- Should be used for the implementation of Ada.Synchronous_Task_Control
62
63 type Task_Body_Access is access procedure;
64 -- Pointer to the task body's entry point (or possibly a wrapper
65 -- declared local to the GNARL).
66
67 type Private_Data is limited private;
68 -- Any information that the GNULLI needs maintained on a per-task basis.
69 -- A component of this type is guaranteed to be included in the
70 -- Ada_Task_Control_Block.
71
72 subtype Task_Address is System.Address;
73 Task_Address_Size : constant := Standard'Address_Size;
74 -- Type used for task addresses and its size
75
76 Alternate_Stack_Size : constant := 0;
77 -- No alternate signal stack is used on this platform
78
79 private
80
81 type Private_Task_Serial_Number is mod 2 ** Long_Long_Integer'Size;
82 -- Used to give each task a unique serial number
83
84 type Base_Lock is new System.OS_Interface.mutex_t;
85
86 type Owner_Int is new Integer;
87 for Owner_Int'Alignment use Standard'Maximum_Alignment;
88
89 type Owner_ID is access all Owner_Int;
90
91 function To_Owner_ID is
92 new Ada.Unchecked_Conversion (System.Address, Owner_ID);
93
94 type Lock is record
95 L : aliased Base_Lock;
96 Ceiling : System.Any_Priority := System.Any_Priority'First;
97 Saved_Priority : System.Any_Priority := System.Any_Priority'First;
98 Owner : Owner_ID;
99 Next : Lock_Ptr;
100 Level : Private_Task_Serial_Number := 0;
101 Buddy : Owner_ID;
102 Frozen : Boolean := False;
103 end record;
104
105 type RTS_Lock is new Lock;
106
107 type Suspension_Object is record
108 State : Boolean;
109 pragma Atomic (State);
110 -- Boolean that indicates whether the object is open. This field is
111 -- marked Atomic to ensure that we can read its value without locking
112 -- the access to the Suspension_Object.
113
114 Waiting : Boolean;
115 -- Flag showing if there is a task already suspended on this object
116
117 L : aliased System.OS_Interface.mutex_t;
118 -- Protection for ensuring mutual exclusion on the Suspension_Object
119
120 CV : aliased System.OS_Interface.cond_t;
121 -- Condition variable used to queue threads until condition is signaled
122 end record;
123
124 -- Note that task support on gdb relies on the fact that the first two
125 -- fields of Private_Data are Thread and LWP.
126
127 type Private_Data is limited record
128 Thread : aliased System.OS_Interface.thread_t;
129 pragma Atomic (Thread);
130 -- Thread field may be updated by two different threads of control.
131 -- (See, Enter_Task and Create_Task in s-taprop.adb). They put the same
132 -- value (thr_self value). We do not want to use lock on those
133 -- operations and the only thing we have to make sure is that they are
134 -- updated in atomic fashion.
135
136 LWP : System.OS_Interface.lwpid_t;
137 -- The LWP id of the thread. Set by self in Enter_Task
138
139 CV : aliased System.OS_Interface.cond_t;
140 L : aliased RTS_Lock;
141 -- Protection for all components is lock L
142
143 Active_Priority : System.Any_Priority := System.Any_Priority'First;
144 -- Simulated active priority, used iff Priority_Ceiling_Support is True
145
146 Locking : Lock_Ptr;
147 Locks : Lock_Ptr;
148 Wakeups : Natural := 0;
149 end record;
150
151 end System.Task_Primitives;