1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- A D A . S Y N C H R O N O U S _ B A R R I E R S -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- 10-- -- 11-- This specification is derived from the Ada Reference Manual for use with -- 12-- GNAT. The copyright notice above, and the license provisions that follow -- 13-- apply solely to the contents of the part following the private keyword. -- 14-- -- 15-- GNAT is free software; you can redistribute it and/or modify it under -- 16-- terms of the GNU General Public License as published by the Free Soft- -- 17-- ware Foundation; either version 3, or (at your option) any later ver- -- 18-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 19-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 20-- or FITNESS FOR A PARTICULAR PURPOSE. -- 21-- -- 22-- As a special exception under Section 7 of GPL version 3, you are granted -- 23-- additional permissions described in the GCC Runtime Library Exception, -- 24-- version 3.1, as published by the Free Software Foundation. -- 25-- -- 26-- You should have received a copy of the GNU General Public License and -- 27-- a copy of the GCC Runtime Library Exception along with this program; -- 28-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 29-- <http://www.gnu.org/licenses/>. -- 30-- -- 31-- GNAT was originally developed by the GNAT team at New York University. -- 32-- Extensive contributions were provided by Ada Core Technologies Inc. -- 33-- -- 34------------------------------------------------------------------------------ 35 36-- This is the body of this package using POSIX barriers 37 38with Interfaces.C; use Interfaces.C; 39 40package body Ada.Synchronous_Barriers is 41 42 -------------------- 43 -- POSIX barriers -- 44 -------------------- 45 46 function pthread_barrier_init 47 (barrier : not null access pthread_barrier_t; 48 attr : System.Address := System.Null_Address; 49 count : unsigned) return int; 50 pragma Import (C, pthread_barrier_init, "pthread_barrier_init"); 51 -- Initialize barrier with the attributes in attr. The barrier is opened 52 -- when count waiters arrived. If attr is null the default barrier 53 -- attributes are used. 54 55 function pthread_barrier_destroy 56 (barrier : not null access pthread_barrier_t) return int; 57 pragma Import (C, pthread_barrier_destroy, "pthread_barrier_destroy"); 58 -- Destroy a previously dynamically initialized barrier 59 60 function pthread_barrier_wait 61 (barrier : not null access pthread_barrier_t) return int; 62 pragma Import (C, pthread_barrier_wait, "pthread_barrier_wait"); 63 -- Wait on barrier 64 65 -------------- 66 -- Finalize -- 67 -------------- 68 69 overriding procedure Finalize (Barrier : in out Synchronous_Barrier) is 70 Result : int; 71 begin 72 Result := pthread_barrier_destroy (Barrier.POSIX_Barrier'Access); 73 pragma Assert (Result = 0); 74 end Finalize; 75 76 overriding procedure Initialize (Barrier : in out Synchronous_Barrier) is 77 Result : int; 78 begin 79 Result := 80 pthread_barrier_init 81 (barrier => Barrier.POSIX_Barrier'Access, 82 attr => System.Null_Address, 83 count => unsigned (Barrier.Release_Threshold)); 84 pragma Assert (Result = 0); 85 end Initialize; 86 87 ---------------------- 88 -- Wait_For_Release -- 89 ---------------------- 90 91 procedure Wait_For_Release 92 (The_Barrier : in out Synchronous_Barrier; 93 Notified : out Boolean) 94 is 95 Result : int; 96 97 PTHREAD_BARRIER_SERIAL_THREAD : constant := -1; 98 -- Value used to indicate the task which receives the notification for 99 -- the barrier open. 100 101 begin 102 Result := 103 pthread_barrier_wait 104 (barrier => The_Barrier.POSIX_Barrier'Access); 105 pragma Assert 106 (Result = 0 or else Result = PTHREAD_BARRIER_SERIAL_THREAD); 107 108 Notified := (Result = PTHREAD_BARRIER_SERIAL_THREAD); 109 end Wait_For_Release; 110 111end Ada.Synchronous_Barriers; 112