| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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) 1991-1994, Florida State University -- |
| -- Copyright (C) 1995-2014, 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 -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- GNARL was developed by the GNARL team at Florida State University. -- |
| -- Extensive contributions were provided by Ada Core Technologies, Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- 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; |
| |
| 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.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; |
| -- 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; |
