| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- A D A . S Y N C H R O N O U S _ B A R R I E R S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2021, Free Software Foundation, Inc. -- |
| -- -- |
| -- This specification is derived from the Ada Reference Manual for use with -- |
| -- GNAT. The copyright notice above, and the license provisions that follow -- |
| -- apply solely to the contents of the part following the private keyword. -- |
| -- -- |
| -- 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/>. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is the body of this package using POSIX barriers |
| |
| with Interfaces.C; use Interfaces.C; |
| |
| package body Ada.Synchronous_Barriers with SPARK_Mode => Off is |
| |
| -------------------- |
| -- POSIX barriers -- |
| -------------------- |
| |
| function pthread_barrier_init |
| (barrier : not null access pthread_barrier_t; |
| attr : System.Address := System.Null_Address; |
| count : unsigned) return int; |
| pragma Import (C, pthread_barrier_init, "pthread_barrier_init"); |
| -- Initialize barrier with the attributes in attr. The barrier is opened |
| -- when count waiters arrived. If attr is null the default barrier |
| -- attributes are used. |
| |
| function pthread_barrier_destroy |
| (barrier : not null access pthread_barrier_t) return int; |
| pragma Import (C, pthread_barrier_destroy, "pthread_barrier_destroy"); |
| -- Destroy a previously dynamically initialized barrier |
| |
| function pthread_barrier_wait |
| (barrier : not null access pthread_barrier_t) return int; |
| pragma Import (C, pthread_barrier_wait, "pthread_barrier_wait"); |
| -- Wait on barrier |
| |
| -------------- |
| -- Finalize -- |
| -------------- |
| |
| overriding procedure Finalize (Barrier : in out Synchronous_Barrier) is |
| Result : int; |
| begin |
| Result := pthread_barrier_destroy (Barrier.POSIX_Barrier'Access); |
| pragma Assert (Result = 0); |
| end Finalize; |
| |
| overriding procedure Initialize (Barrier : in out Synchronous_Barrier) is |
| Result : int; |
| begin |
| Result := |
| pthread_barrier_init |
| (barrier => Barrier.POSIX_Barrier'Access, |
| attr => System.Null_Address, |
| count => unsigned (Barrier.Release_Threshold)); |
| pragma Assert (Result = 0); |
| end Initialize; |
| |
| ---------------------- |
| -- Wait_For_Release -- |
| ---------------------- |
| |
| procedure Wait_For_Release |
| (The_Barrier : in out Synchronous_Barrier; |
| Notified : out Boolean) |
| is |
| Result : int; |
| |
| PTHREAD_BARRIER_SERIAL_THREAD : constant := -1; |
| -- Value used to indicate the task which receives the notification for |
| -- the barrier open. |
| |
| begin |
| Result := |
| pthread_barrier_wait |
| (barrier => The_Barrier.POSIX_Barrier'Access); |
| pragma Assert |
| (Result = 0 or else Result = PTHREAD_BARRIER_SERIAL_THREAD); |
| |
| Notified := (Result = PTHREAD_BARRIER_SERIAL_THREAD); |
| end Wait_For_Release; |
| |
| end Ada.Synchronous_Barriers; |
