97 lines
5.2 KiB
Ada
97 lines
5.2 KiB
Ada
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------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
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-- --
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-- S Y S T E M . T A S K I N G . E N T R Y _ C A L L S --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 1992-2020, Free Software Foundation, Inc. --
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-- --
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-- GNARL is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNARL was developed by the GNARL team at Florida State University. --
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-- Extensive contributions were provided by Ada Core Technologies, Inc. --
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-- --
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------------------------------------------------------------------------------
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-- This package provides internal RTS calls implementing operations
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-- that apply to general entry calls, that is, calls to either
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-- protected or task entries.
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-- These declarations are not part of the GNARL Interface
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package System.Tasking.Entry_Calls is
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procedure Wait_For_Completion (Entry_Call : Entry_Call_Link);
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-- This procedure suspends the calling task until the specified entry
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-- call has either been completed or cancelled. It performs other
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-- operations required of suspended tasks, such as performing
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-- dynamic priority changes. On exit, the call will not be queued.
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-- This waits for calls on task or protected entries.
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-- Abortion must be deferred when calling this procedure.
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-- Call this only when holding Self (= Entry_Call.Self) or global RTS lock.
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procedure Wait_For_Completion_With_Timeout
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(Entry_Call : Entry_Call_Link;
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Wakeup_Time : Duration;
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Mode : Delay_Modes;
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Yielded : out Boolean);
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-- Same as Wait_For_Completion but wait for a timeout with the value
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-- specified in Wakeup_Time as well.
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-- On return, Yielded indicates whether the wait has performed a yield.
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-- Check_Exception must be called after calling this procedure.
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procedure Wait_Until_Abortable
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(Self_ID : Task_Id;
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Call : Entry_Call_Link);
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-- This procedure suspends the calling task until the specified entry
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-- call is queued abortably or completes.
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-- Abortion must be deferred when calling this procedure.
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procedure Try_To_Cancel_Entry_Call (Succeeded : out Boolean);
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pragma Inline (Try_To_Cancel_Entry_Call);
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-- Try to cancel async. entry call.
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-- Effect includes Abort_To_Level and Wait_For_Completion.
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-- Cancelled = True iff the cancellation was successful, i.e.,
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-- the call was not Done before this call.
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-- On return, the call is off-queue and the ATC level is reduced by one.
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procedure Reset_Priority
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(Acceptor : Task_Id;
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Acceptor_Prev_Priority : Rendezvous_Priority);
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pragma Inline (Reset_Priority);
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-- Reset the priority of a task completing an accept statement to
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-- the value it had before the call.
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-- Acceptor should always be equal to Self.
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procedure Check_Exception
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(Self_ID : Task_Id;
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Entry_Call : Entry_Call_Link);
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pragma Inline (Check_Exception);
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-- Raise any pending exception from the Entry_Call.
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-- This should be called at the end of every compiler interface procedure
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-- that implements an entry call.
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-- In principle, the caller should not be abort-deferred (unless the
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-- application program violates the Ada language rules by doing entry calls
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-- from within protected operations -- an erroneous practice apparently
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-- followed with success by some adventurous GNAT users).
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-- Absolutely, the caller should not be holding any locks, or there
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-- will be deadlock.
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end System.Tasking.Entry_Calls;
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