------------------------------------------------------------------------------ -- -- -- 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) 1992-2011, 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 -- -- . -- -- -- -- 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 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 shall be 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;