------------------------------------------------------------------------------ -- -- -- 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. -- -- -- ------------------------------------------------------------------------------ package body Ada.Synchronous_Barriers is protected body Synchronous_Barrier is -- The condition "Wait'Count = Release_Threshold" opens the barrier when -- the required number of tasks is reached. The condition "Keep_Open" -- leaves the barrier open while there are queued tasks. While there are -- tasks in the queue no new task will be queued (no new protected -- action can be started on a protected object while another protected -- action on the same protected object is underway, RM 9.5.1 (4)), -- guaranteeing that the barrier will remain open only for those tasks -- already inside the queue when the barrier was open. entry Wait (Notified : out Boolean) when Keep_Open or else Wait'Count = Release_Threshold is begin -- If we are executing the entry it means that the required number of -- tasks have been queued in the entry. Keep_Open barrier will remain -- true until all queued tasks are out. Keep_Open := Wait'Count > 0; -- The last released task will close the barrier and get the Notified -- token. Notified := Wait'Count = 0; end Wait; end Synchronous_Barrier; ---------------------- -- Wait_For_Release -- ---------------------- procedure Wait_For_Release (The_Barrier : in out Synchronous_Barrier; Notified : out Boolean) is begin The_Barrier.Wait (Notified); end Wait_For_Release; end Ada.Synchronous_Barriers;