1------------------------------------------------------------------------------ 2-- -- 3-- GNU ADA 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) 1991-2001 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 2, or (at your option) any later ver- -- 14-- sion. GNARL 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. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNARL; see file COPYING. If not, write -- 19-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 22-- As a special exception, if other files instantiate generics from this -- 23-- unit, or you link this unit with other files to produce an executable, -- 24-- this unit does not by itself cause the resulting executable to be -- 25-- covered by the GNU General Public License. This exception does not -- 26-- however invalidate any other reasons why the executable file might be -- 27-- covered by the GNU Public License. -- 28-- -- 29-- GNARL was developed by the GNARL team at Florida State University. -- 30-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 31-- -- 32------------------------------------------------------------------------------ 33 34-- This is the GNU/Linux (GNU/LinuxThreads) version of this package. 35 36-- This package provides low-level support for most tasking features. 37 38pragma Polling (Off); 39-- Turn off polling, we do not want ATC polling to take place during 40-- tasking operations. It causes infinite loops and other problems. 41 42with System.OS_Interface; 43-- used for pthread_mutex_t 44-- pthread_cond_t 45-- pthread_t 46 47package System.Task_Primitives is 48 49 type Lock is limited private; 50 -- Should be used for implementation of protected objects. 51 52 type RTS_Lock is limited private; 53 -- Should be used inside the runtime system. 54 -- The difference between Lock and the RTS_Lock is that the later 55 -- one serves only as a semaphore so that do not check for 56 -- ceiling violations. 57 58 type Task_Body_Access is access procedure; 59 -- Pointer to the task body's entry point (or possibly a wrapper 60 -- declared local to the GNARL). 61 62 type Private_Data is limited private; 63 -- Any information that the GNULLI needs maintained on a per-task 64 -- basis. A component of this type is guaranteed to be included 65 -- in the Ada_Task_Control_Block. 66 67private 68 69 type Prio_Array_Type is array (System.Any_Priority) of Integer; 70 71 type Lock is record 72 L : aliased System.OS_Interface.pthread_mutex_t; 73 Ceiling : System.Any_Priority := System.Any_Priority'First; 74 Saved_Priority : System.Any_Priority := System.Any_Priority'First; 75 end record; 76 77 type RTS_Lock is new System.OS_Interface.pthread_mutex_t; 78 type Private_Data is record 79 Thread : aliased System.OS_Interface.pthread_t; 80 pragma Atomic (Thread); 81 -- Thread field may be updated by two different threads of control. 82 -- (See, Enter_Task and Create_Task in s-taprop.adb). 83 -- They put the same value (thr_self value). We do not want to 84 -- use lock on those operations and the only thing we have to 85 -- make sure is that they are updated in atomic fashion. 86 87 CV : aliased System.OS_Interface.pthread_cond_t; 88 L : aliased RTS_Lock; 89 -- protection for all components is lock L 90 91 Active_Priority : System.Any_Priority := System.Any_Priority'First; 92 -- Simulated active priority, 93 -- used only if Priority_Ceiling_Support is True. 94 end record; 95 96end System.Task_Primitives; 97