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Diffstat (limited to 'gcc-4.8.3/gcc/ada/a-synbar.adb')
-rw-r--r-- | gcc-4.8.3/gcc/ada/a-synbar.adb | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/a-synbar.adb b/gcc-4.8.3/gcc/ada/a-synbar.adb new file mode 100644 index 000000000..33bb3e478 --- /dev/null +++ b/gcc-4.8.3/gcc/ada/a-synbar.adb @@ -0,0 +1,78 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 -- +-- <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. -- +-- -- +------------------------------------------------------------------------------ + +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; |