1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- S Y S T E M . T A S K I N G . E N T R Y _ C A L L S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- 10-- -- 11-- GNARL is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNARL was developed by the GNARL team at Florida State University. -- 28-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package provides internal RTS calls implementing operations 33-- that apply to general entry calls, that is, calls to either 34-- protected or task entries. 35 36-- These declarations are not part of the GNARL Interface 37 38package System.Tasking.Entry_Calls is 39 40 procedure Wait_For_Completion (Entry_Call : Entry_Call_Link); 41 -- This procedure suspends the calling task until the specified entry 42 -- call has either been completed or cancelled. It performs other 43 -- operations required of suspended tasks, such as performing 44 -- dynamic priority changes. On exit, the call will not be queued. 45 -- This waits for calls on task or protected entries. 46 -- Abortion must be deferred when calling this procedure. 47 -- Call this only when holding Self (= Entry_Call.Self) or global RTS lock. 48 49 procedure Wait_For_Completion_With_Timeout 50 (Entry_Call : Entry_Call_Link; 51 Wakeup_Time : Duration; 52 Mode : Delay_Modes; 53 Yielded : out Boolean); 54 -- Same as Wait_For_Completion but wait for a timeout with the value 55 -- specified in Wakeup_Time as well. 56 -- On return, Yielded indicates whether the wait has performed a yield. 57 -- Check_Exception must be called after calling this procedure. 58 59 procedure Wait_Until_Abortable 60 (Self_ID : Task_Id; 61 Call : Entry_Call_Link); 62 -- This procedure suspends the calling task until the specified entry 63 -- call is queued abortably or completes. 64 -- Abortion must be deferred when calling this procedure, and the global 65 -- RTS lock taken when Single_Lock. 66 67 procedure Try_To_Cancel_Entry_Call (Succeeded : out Boolean); 68 pragma Inline (Try_To_Cancel_Entry_Call); 69 -- Try to cancel async. entry call. 70 -- Effect includes Abort_To_Level and Wait_For_Completion. 71 -- Cancelled = True iff the cancellation was successful, i.e., 72 -- the call was not Done before this call. 73 -- On return, the call is off-queue and the ATC level is reduced by one. 74 75 procedure Reset_Priority 76 (Acceptor : Task_Id; 77 Acceptor_Prev_Priority : Rendezvous_Priority); 78 pragma Inline (Reset_Priority); 79 -- Reset the priority of a task completing an accept statement to 80 -- the value it had before the call. 81 -- Acceptor should always be equal to Self. 82 83 procedure Check_Exception 84 (Self_ID : Task_Id; 85 Entry_Call : Entry_Call_Link); 86 pragma Inline (Check_Exception); 87 -- Raise any pending exception from the Entry_Call. 88 -- This should be called at the end of every compiler interface procedure 89 -- that implements an entry call. 90 -- In principle, the caller should not be abort-deferred (unless the 91 -- application program violates the Ada language rules by doing entry calls 92 -- from within protected operations -- an erroneous practice apparently 93 -- followed with success by some adventurous GNAT users). 94 -- Absolutely, the caller should not be holding any locks, or there 95 -- will be deadlock. 96 97end System.Tasking.Entry_Calls; 98