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) 1992-2011, 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 Solaris version of this package 33 34-- This package provides low-level support for most tasking features 35 36pragma 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 40with Ada.Unchecked_Conversion; 41 42with System.OS_Interface; 43 44package 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 -- In some versions of Task_Primitives, notably for VMS, Task_Address is 74 -- the short version of address defined in System.Aux_DEC. To avoid 75 -- dragging Aux_DEC into tasking packages a tasking specific subtype is 76 -- defined here. 77 78 Task_Address_Size : constant := Standard'Address_Size; 79 -- The size of Task_Address 80 81 Alternate_Stack_Size : constant := 0; 82 -- No alternate signal stack is used on this platform 83 84private 85 86 type Private_Task_Serial_Number is mod 2 ** 64; 87 -- Used to give each task a unique serial number 88 89 type Base_Lock is new System.OS_Interface.mutex_t; 90 91 type Owner_Int is new Integer; 92 for Owner_Int'Alignment use Standard'Maximum_Alignment; 93 94 type Owner_ID is access all Owner_Int; 95 96 function To_Owner_ID is 97 new Ada.Unchecked_Conversion (System.Address, Owner_ID); 98 99 type Lock is record 100 L : aliased Base_Lock; 101 Ceiling : System.Any_Priority := System.Any_Priority'First; 102 Saved_Priority : System.Any_Priority := System.Any_Priority'First; 103 Owner : Owner_ID; 104 Next : Lock_Ptr; 105 Level : Private_Task_Serial_Number := 0; 106 Buddy : Owner_ID; 107 Frozen : Boolean := False; 108 end record; 109 110 type RTS_Lock is new Lock; 111 112 type Suspension_Object is record 113 State : Boolean; 114 pragma Atomic (State); 115 -- Boolean that indicates whether the object is open. This field is 116 -- marked Atomic to ensure that we can read its value without locking 117 -- the access to the Suspension_Object. 118 119 Waiting : Boolean; 120 -- Flag showing if there is a task already suspended on this object 121 122 L : aliased System.OS_Interface.mutex_t; 123 -- Protection for ensuring mutual exclusion on the Suspension_Object 124 125 CV : aliased System.OS_Interface.cond_t; 126 -- Condition variable used to queue threads until condition is signaled 127 end record; 128 129 -- Note that task support on gdb relies on the fact that the first two 130 -- fields of Private_Data are Thread and LWP. 131 132 type Private_Data is record 133 Thread : aliased System.OS_Interface.thread_t; 134 pragma Atomic (Thread); 135 -- Thread field may be updated by two different threads of control. 136 -- (See, Enter_Task and Create_Task in s-taprop.adb). They put the same 137 -- value (thr_self value). We do not want to use lock on those 138 -- operations and the only thing we have to make sure is that they are 139 -- updated in atomic fashion. 140 141 LWP : System.OS_Interface.lwpid_t; 142 -- The LWP id of the thread. Set by self in Enter_Task 143 144 CV : aliased System.OS_Interface.cond_t; 145 L : aliased RTS_Lock; 146 -- Protection for all components is lock L 147 148 Active_Priority : System.Any_Priority := System.Any_Priority'First; 149 -- Simulated active priority, used iff Priority_Ceiling_Support is True 150 151 Locking : Lock_Ptr; 152 Locks : Lock_Ptr; 153 Wakeups : Natural := 0; 154 end record; 155 156end System.Task_Primitives; 157