------------------------------------------------------------------------------ -- -- -- GNAT 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) 1991-2017, Florida State University -- -- Copyright (C) 1995-2018, AdaCore -- -- -- -- GNAT 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 3, or (at your option) any later ver- -- -- sion. GNAT 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. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- This is LynxOS Family version of this package. 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; package System.Task_Primitives is pragma Preelaborate; 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 latter serves only as a semaphore so that -- we do not check for ceiling violations. type Suspension_Object is limited private; -- Should be used for the implementation of Ada.Synchronous_Task_Control 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. subtype Task_Address is System.Address; Task_Address_Size : constant := Standard'Address_Size; -- Type used for task addresses and its size Alternate_Stack_Size : constant := System.OS_Interface.Alternate_Stack_Size; -- Import value from System.OS_Interface private type Lock is record RW : aliased System.OS_Interface.pthread_rwlock_t; WO : aliased System.OS_Interface.pthread_mutex_t; end record; type RTS_Lock is new System.OS_Interface.pthread_mutex_t; type Suspension_Object is record State : Boolean; pragma Atomic (State); -- Boolean that indicates whether the object is open. This field is -- marked Atomic to ensure that we can read its value without locking -- the access to the Suspension_Object. Waiting : Boolean; -- Flag showing if there is a task already suspended on this object L : aliased System.OS_Interface.pthread_mutex_t; -- Protection for ensuring mutual exclusion on the Suspension_Object CV : aliased System.OS_Interface.pthread_cond_t; -- Condition variable used to queue threads until condition is signaled end record; type Private_Data is limited 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.OS_Interface.pthread_t; -- 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; -- Should be commented ??? (in all versions of taspri) L : aliased RTS_Lock; -- Protection for all components is lock L end record; end System.Task_Primitives;