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) 1991-2011, 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-- 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. -- 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 NT (native) version of this package 33 34pragma Polling (Off); 35-- Turn off polling, we do not want ATC polling to take place during tasking 36-- operations. It causes infinite loops and other problems. 37 38with System.OS_Interface; 39with System.Win32; 40 41package System.Task_Primitives is 42 pragma Preelaborate; 43 44 type Lock is limited private; 45 -- Should be used for implementation of protected objects 46 47 type RTS_Lock is limited private; 48 -- Should be used inside the runtime system. The difference between Lock 49 -- and the RTS_Lock is that the later one serves only as a semaphore so 50 -- that do not check for ceiling violations. 51 52 type Suspension_Object is limited private; 53 -- Should be used for the implementation of Ada.Synchronous_Task_Control 54 55 type Task_Body_Access is access procedure; 56 -- Pointer to the task body's entry point (or possibly a wrapper 57 -- declared local to the GNARL). 58 59 type Private_Data is limited private; 60 -- Any information that the GNULLI needs maintained on a per-task basis. 61 -- A component of this type is guaranteed to be included in the 62 -- Ada_Task_Control_Block. 63 64 subtype Task_Address is System.Address; 65 -- In some versions of Task_Primitives, notably for VMS, Task_Address is 66 -- the short version of address defined in System.Aux_DEC. To avoid 67 -- dragging Aux_DEC into tasking packages a tasking specific subtype is 68 -- defined here. 69 70 Task_Address_Size : constant := Standard'Address_Size; 71 -- The size of Task_Address 72 73 Alternate_Stack_Size : constant := 0; 74 -- No alternate signal stack is used on this platform 75 76private 77 78 type Lock is record 79 Mutex : aliased System.OS_Interface.CRITICAL_SECTION; 80 Priority : Integer; 81 Owner_Priority : Integer; 82 end record; 83 84 type Condition_Variable is new System.Win32.HANDLE; 85 86 type RTS_Lock is new System.OS_Interface.CRITICAL_SECTION; 87 88 type Suspension_Object is record 89 State : Boolean; 90 pragma Atomic (State); 91 -- Boolean that indicates whether the object is open. This field is 92 -- marked Atomic to ensure that we can read its value without locking 93 -- the access to the Suspension_Object. 94 95 Waiting : Boolean; 96 -- Flag showing if there is a task already suspended on this object 97 98 L : aliased System.OS_Interface.CRITICAL_SECTION; 99 -- Protection for ensuring mutual exclusion on the Suspension_Object 100 101 CV : aliased Win32.HANDLE; 102 -- Condition variable used to queue threads until condition is signaled 103 end record; 104 105 type Private_Data is record 106 Thread : aliased Win32.HANDLE; 107 pragma Atomic (Thread); 108 -- Thread field may be updated by two different threads of control. 109 -- (See, Enter_Task and Create_Task in s-taprop.adb). 110 -- They put the same value (thr_self value). We do not want to 111 -- use lock on those operations and the only thing we have to 112 -- make sure is that they are updated in atomic fashion. 113 114 Thread_Id : aliased Win32.DWORD; 115 -- Used to provide a better tasking support in gdb 116 117 CV : aliased Condition_Variable; 118 -- Condition Variable used to implement Sleep/Wakeup 119 120 L : aliased RTS_Lock; 121 -- Protection for all components is lock L 122 end record; 123 124end System.Task_Primitives; 125