------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . T A S K _ P R I M I T I V E S -- -- -- -- S p e c -- -- -- -- -- -- Copyright (C) 1991-2000, Florida State University -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNARL is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNARL; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- -- State University (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This is a POSIX-like version of this package. -- Note: this file can only be used for POSIX compliant systems. pragma Polling (Off); -- Turn off polling, we do not want ATC polling to take place during -- tasking operations. It causes infinite loops and other problems. with System.OS_Interface; -- used for pthread_mutex_t -- pthread_cond_t -- pthread_t package System.Task_Primitives is type Lock is limited private; -- Should be used for implementation of protected objects. type RTS_Lock is limited private; -- Should be used inside the runtime system. -- The difference between Lock and the RTS_Lock is that the later -- one serves only as a semaphore so that do not check for -- ceiling violations. type Task_Body_Access is access procedure; -- Pointer to the task body's entry point (or possibly a wrapper -- declared local to the GNARL). type Private_Data is limited private; -- Any information that the GNULLI needs maintained on a per-task -- basis. A component of this type is guaranteed to be included -- in the Ada_Task_Control_Block. private type Lock is new System.OS_Interface.pthread_mutex_t; type RTS_Lock is new System.OS_Interface.pthread_mutex_t; type Private_Data is record Thread : aliased System.OS_Interface.pthread_t; pragma Atomic (Thread); -- Thread field may be updated by two different threads of control. -- (See, Enter_Task and Create_Task in s-taprop.adb). -- They put the same value (thr_self value). We do not want to -- use lock on those operations and the only thing we have to -- make sure is that they are updated in atomic fashion. LWP : aliased System.Address; -- The purpose of this field is to provide a better tasking support on -- gdb. The order of the two first fields (Thread and LWP) is important. -- On targets where lwp is not relevant, this is equivalent to Thread. CV : aliased System.OS_Interface.pthread_cond_t; L : aliased RTS_Lock; -- Protection for all components is lock L end record; end System.Task_Primitives;