1362 lines
38 KiB
Ada
1362 lines
38 KiB
Ada
------------------------------------------------------------------------------
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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 _ P R I M I T I V E S . O P E R A T I O N S --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2009, 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 is a Tru64 version of this package
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-- This package contains all the GNULL primitives that interface directly with
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-- the underlying OS.
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pragma Polling (Off);
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-- Turn off polling, we do not want ATC polling to take place during tasking
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-- operations. It causes infinite loops and other problems.
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with Ada.Unchecked_Deallocation;
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with Interfaces;
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with Interfaces.C;
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with System.Tasking.Debug;
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with System.Interrupt_Management;
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with System.OS_Primitives;
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with System.Task_Info;
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with System.Soft_Links;
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-- We use System.Soft_Links instead of System.Tasking.Initialization
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-- because the later is a higher level package that we shouldn't depend on.
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-- For example when using the restricted run time, it is replaced by
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-- System.Tasking.Restricted.Stages.
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package body System.Task_Primitives.Operations is
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package SSL renames System.Soft_Links;
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use System.Tasking.Debug;
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use System.Tasking;
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use Interfaces.C;
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use System.OS_Interface;
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use System.Parameters;
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use System.OS_Primitives;
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----------------
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-- Local Data --
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----------------
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-- The followings are logically constants, but need to be initialized
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-- at run time.
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Single_RTS_Lock : aliased RTS_Lock;
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-- This is a lock to allow only one thread of control in the RTS at
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-- a time; it is used to execute in mutual exclusion from all other tasks.
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-- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
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ATCB_Key : aliased pthread_key_t;
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-- Key used to find the Ada Task_Id associated with a thread
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Environment_Task_Id : Task_Id;
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-- A variable to hold Task_Id for the environment task
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Unblocked_Signal_Mask : aliased sigset_t;
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-- The set of signals that should unblocked in all tasks
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Time_Slice_Val : Integer;
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pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
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Locking_Policy : Character;
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pragma Import (C, Locking_Policy, "__gl_locking_policy");
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Dispatching_Policy : Character;
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pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
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Curpid : pid_t;
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Foreign_Task_Elaborated : aliased Boolean := True;
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-- Used to identified fake tasks (i.e., non-Ada Threads)
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Abort_Handler_Installed : Boolean := False;
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-- True if a handler for the abort signal is installed
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--------------------
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-- Local Packages --
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--------------------
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package Specific is
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procedure Initialize (Environment_Task : Task_Id);
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pragma Inline (Initialize);
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-- Initialize various data needed by this package
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function Is_Valid_Task return Boolean;
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pragma Inline (Is_Valid_Task);
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-- Does executing thread have a TCB?
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procedure Set (Self_Id : Task_Id);
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pragma Inline (Set);
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-- Set the self id for the current task
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function Self return Task_Id;
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pragma Inline (Self);
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-- Return a pointer to the Ada Task Control Block of the calling task
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end Specific;
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package body Specific is separate;
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-- The body of this package is target specific
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---------------------------------
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-- Support for foreign threads --
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---------------------------------
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function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
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-- Allocate and initialize a new ATCB for the current Thread
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function Register_Foreign_Thread
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(Thread : Thread_Id) return Task_Id is separate;
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Abort_Handler (Sig : Signal);
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-- Signal handler used to implement asynchronous abort
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function Get_Policy (Prio : System.Any_Priority) return Character;
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pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
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-- Get priority specific dispatching policy
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-------------------
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-- Abort_Handler --
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-------------------
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procedure Abort_Handler (Sig : Signal) is
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pragma Unreferenced (Sig);
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T : constant Task_Id := Self;
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Old_Set : aliased sigset_t;
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Result : Interfaces.C.int;
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pragma Warnings (Off, Result);
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begin
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-- It's not safe to raise an exception when using GCC ZCX mechanism.
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-- Note that we still need to install a signal handler, since in some
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-- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
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-- need to send the Abort signal to a task.
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if ZCX_By_Default and then GCC_ZCX_Support then
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return;
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end if;
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if T.Deferral_Level = 0
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and then T.Pending_ATC_Level < T.ATC_Nesting_Level
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and then not T.Aborting
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then
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T.Aborting := True;
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-- Make sure signals used for RTS internal purpose are unmasked
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Result :=
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pthread_sigmask
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(SIG_UNBLOCK,
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Unblocked_Signal_Mask'Access,
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Old_Set'Access);
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pragma Assert (Result = 0);
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raise Standard'Abort_Signal;
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end if;
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end Abort_Handler;
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------------------
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-- Stack_Guard --
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------------------
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-- The underlying thread system sets a guard page at the bottom of a thread
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-- stack, so nothing is needed.
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procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
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pragma Unreferenced (T);
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pragma Unreferenced (On);
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begin
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null;
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end Stack_Guard;
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--------------------
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-- Get_Thread_Id --
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--------------------
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function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
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begin
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return T.Common.LL.Thread;
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end Get_Thread_Id;
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----------
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-- Self --
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----------
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function Self return Task_Id renames Specific.Self;
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---------------------
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-- Initialize_Lock --
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---------------------
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-- Note: mutexes and cond_variables needed per-task basis are initialized
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-- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
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-- as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
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-- status change of RTS. Therefore raising Storage_Error in the following
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-- routines should be able to be handled safely.
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procedure Initialize_Lock
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(Prio : System.Any_Priority;
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L : not null access Lock)
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is
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Attributes : aliased pthread_mutexattr_t;
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Result : Interfaces.C.int;
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begin
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Result := pthread_mutexattr_init (Attributes'Access);
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pragma Assert (Result = 0 or else Result = ENOMEM);
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if Result = ENOMEM then
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raise Storage_Error;
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end if;
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if Locking_Policy = 'C' then
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L.Ceiling := Interfaces.C.int (Prio);
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end if;
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Result := pthread_mutex_init (L.L'Access, Attributes'Access);
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pragma Assert (Result = 0 or else Result = ENOMEM);
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if Result = ENOMEM then
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Result := pthread_mutexattr_destroy (Attributes'Access);
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raise Storage_Error;
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end if;
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Result := pthread_mutexattr_destroy (Attributes'Access);
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pragma Assert (Result = 0);
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end Initialize_Lock;
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procedure Initialize_Lock
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(L : not null access RTS_Lock;
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Level : Lock_Level)
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is
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pragma Unreferenced (Level);
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Attributes : aliased pthread_mutexattr_t;
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Result : Interfaces.C.int;
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begin
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Result := pthread_mutexattr_init (Attributes'Access);
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pragma Assert (Result = 0 or else Result = ENOMEM);
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if Result = ENOMEM then
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raise Storage_Error;
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end if;
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Result := pthread_mutex_init (L, Attributes'Access);
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pragma Assert (Result = 0 or else Result = ENOMEM);
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if Result = ENOMEM then
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Result := pthread_mutexattr_destroy (Attributes'Access);
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raise Storage_Error;
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end if;
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Result := pthread_mutexattr_destroy (Attributes'Access);
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pragma Assert (Result = 0);
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end Initialize_Lock;
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-------------------
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-- Finalize_Lock --
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-------------------
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procedure Finalize_Lock (L : not null access Lock) is
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Result : Interfaces.C.int;
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begin
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Result := pthread_mutex_destroy (L.L'Access);
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pragma Assert (Result = 0);
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end Finalize_Lock;
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procedure Finalize_Lock (L : not null access RTS_Lock) is
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Result : Interfaces.C.int;
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begin
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Result := pthread_mutex_destroy (L);
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pragma Assert (Result = 0);
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end Finalize_Lock;
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----------------
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-- Write_Lock --
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----------------
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procedure Write_Lock
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(L : not null access Lock;
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Ceiling_Violation : out Boolean)
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is
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Result : Interfaces.C.int;
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Self_ID : Task_Id;
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All_Tasks_Link : Task_Id;
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Current_Prio : System.Any_Priority;
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begin
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-- Perform ceiling checks only when this is the locking policy in use
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if Locking_Policy = 'C' then
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Self_ID := Self;
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All_Tasks_Link := Self_ID.Common.All_Tasks_Link;
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Current_Prio := Get_Priority (Self_ID);
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-- If there is no other task, no need to check priorities
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if All_Tasks_Link /= Null_Task
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and then L.Ceiling < Interfaces.C.int (Current_Prio)
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then
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Ceiling_Violation := True;
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return;
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end if;
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end if;
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Result := pthread_mutex_lock (L.L'Access);
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pragma Assert (Result = 0);
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Ceiling_Violation := False;
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end Write_Lock;
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procedure Write_Lock
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(L : not null access RTS_Lock;
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Global_Lock : Boolean := False)
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is
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Result : Interfaces.C.int;
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begin
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if not Single_Lock or else Global_Lock then
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Result := pthread_mutex_lock (L);
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pragma Assert (Result = 0);
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end if;
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end Write_Lock;
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procedure Write_Lock (T : Task_Id) is
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Result : Interfaces.C.int;
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begin
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if not Single_Lock then
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Result := pthread_mutex_lock (T.Common.LL.L'Access);
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pragma Assert (Result = 0);
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end if;
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end Write_Lock;
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---------------
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-- Read_Lock --
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---------------
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procedure Read_Lock
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(L : not null access Lock;
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Ceiling_Violation : out Boolean)
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is
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begin
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Write_Lock (L, Ceiling_Violation);
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end Read_Lock;
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------------
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-- Unlock --
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------------
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procedure Unlock (L : not null access Lock) is
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Result : Interfaces.C.int;
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begin
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Result := pthread_mutex_unlock (L.L'Access);
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pragma Assert (Result = 0);
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end Unlock;
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procedure Unlock
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(L : not null access RTS_Lock;
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Global_Lock : Boolean := False)
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is
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Result : Interfaces.C.int;
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begin
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if not Single_Lock or else Global_Lock then
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Result := pthread_mutex_unlock (L);
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pragma Assert (Result = 0);
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end if;
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end Unlock;
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procedure Unlock (T : Task_Id) is
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Result : Interfaces.C.int;
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begin
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if not Single_Lock then
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Result := pthread_mutex_unlock (T.Common.LL.L'Access);
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pragma Assert (Result = 0);
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end if;
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end Unlock;
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-----------------
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-- Set_Ceiling --
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-----------------
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-- Dynamic priority ceilings are not supported by the underlying system
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procedure Set_Ceiling
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(L : not null access Lock;
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Prio : System.Any_Priority)
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is
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pragma Unreferenced (L, Prio);
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begin
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null;
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end Set_Ceiling;
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-----------
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-- Sleep --
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-----------
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procedure Sleep
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(Self_ID : Task_Id;
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Reason : System.Tasking.Task_States)
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is
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pragma Unreferenced (Reason);
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Result : Interfaces.C.int;
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begin
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Result :=
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pthread_cond_wait
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(cond => Self_ID.Common.LL.CV'Access,
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mutex => (if Single_Lock
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then Single_RTS_Lock'Access
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else Self_ID.Common.LL.L'Access));
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-- EINTR is not considered a failure
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pragma Assert (Result = 0 or else Result = EINTR);
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end Sleep;
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-----------------
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-- Timed_Sleep --
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-----------------
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-- This is for use within the run-time system, so abort is assumed to be
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-- already deferred, and the caller should be holding its own ATCB lock.
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procedure Timed_Sleep
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(Self_ID : Task_Id;
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Time : Duration;
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Mode : ST.Delay_Modes;
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Reason : System.Tasking.Task_States;
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Timedout : out Boolean;
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Yielded : out Boolean)
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is
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pragma Unreferenced (Reason);
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Base_Time : constant Duration := Monotonic_Clock;
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Check_Time : Duration := Base_Time;
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Abs_Time : Duration;
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Request : aliased timespec;
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Result : Interfaces.C.int;
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begin
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Timedout := True;
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Yielded := False;
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Abs_Time :=
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(if Mode = Relative
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then Duration'Min (Time, Max_Sensible_Delay) + Check_Time
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else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
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if Abs_Time > Check_Time then
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Request := To_Timespec (Abs_Time);
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loop
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exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
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Result :=
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pthread_cond_timedwait
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(cond => Self_ID.Common.LL.CV'Access,
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mutex => (if Single_Lock
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then Single_RTS_Lock'Access
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else Self_ID.Common.LL.L'Access),
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abstime => Request'Access);
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Check_Time := Monotonic_Clock;
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exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
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if Result = 0 or Result = EINTR then
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-- Somebody may have called Wakeup for us
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Timedout := False;
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exit;
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end if;
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pragma Assert (Result = ETIMEDOUT);
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end loop;
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end if;
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end Timed_Sleep;
|
|
|
|
-----------------
|
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-- Timed_Delay --
|
|
-----------------
|
|
|
|
-- This is for use in implementing delay statements, so we assume the
|
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-- caller is abort-deferred but is holding no locks.
|
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|
|
procedure Timed_Delay
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(Self_ID : Task_Id;
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Time : Duration;
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Mode : ST.Delay_Modes)
|
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is
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Base_Time : constant Duration := Monotonic_Clock;
|
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Check_Time : Duration := Base_Time;
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Abs_Time : Duration;
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Request : aliased timespec;
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Result : Interfaces.C.int;
|
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|
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begin
|
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if Single_Lock then
|
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Lock_RTS;
|
|
end if;
|
|
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Write_Lock (Self_ID);
|
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Abs_Time :=
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(if Mode = Relative
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then Time + Check_Time
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else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
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|
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if Abs_Time > Check_Time then
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Request := To_Timespec (Abs_Time);
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Self_ID.Common.State := Delay_Sleep;
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|
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loop
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exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
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|
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Result :=
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pthread_cond_timedwait
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(cond => Self_ID.Common.LL.CV'Access,
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mutex => (if Single_Lock
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then Single_RTS_Lock'Access
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else Self_ID.Common.LL.L'Access),
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|
abstime => Request'Access);
|
|
|
|
Check_Time := Monotonic_Clock;
|
|
exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
|
|
|
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pragma Assert (Result = 0 or else
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Result = ETIMEDOUT or else
|
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Result = EINTR);
|
|
end loop;
|
|
|
|
Self_ID.Common.State := Runnable;
|
|
end if;
|
|
|
|
Unlock (Self_ID);
|
|
|
|
if Single_Lock then
|
|
Unlock_RTS;
|
|
end if;
|
|
|
|
Yield;
|
|
end Timed_Delay;
|
|
|
|
---------------------
|
|
-- Monotonic_Clock --
|
|
---------------------
|
|
|
|
function Monotonic_Clock return Duration is
|
|
TS : aliased timespec;
|
|
Result : Interfaces.C.int;
|
|
begin
|
|
Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
|
|
pragma Assert (Result = 0);
|
|
return To_Duration (TS);
|
|
end Monotonic_Clock;
|
|
|
|
-------------------
|
|
-- RT_Resolution --
|
|
-------------------
|
|
|
|
function RT_Resolution return Duration is
|
|
begin
|
|
-- Returned value must be an integral multiple of Duration'Small (1 ns)
|
|
-- The following is the best approximation of 1/1024. The clock on the
|
|
-- DEC Alpha ticks at 1024 Hz.
|
|
|
|
return 0.000_976_563;
|
|
end RT_Resolution;
|
|
|
|
------------
|
|
-- Wakeup --
|
|
------------
|
|
|
|
procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
|
|
pragma Unreferenced (Reason);
|
|
Result : Interfaces.C.int;
|
|
begin
|
|
Result := pthread_cond_signal (T.Common.LL.CV'Access);
|
|
pragma Assert (Result = 0);
|
|
end Wakeup;
|
|
|
|
-----------
|
|
-- Yield --
|
|
-----------
|
|
|
|
procedure Yield (Do_Yield : Boolean := True) is
|
|
Result : Interfaces.C.int;
|
|
pragma Unreferenced (Result);
|
|
begin
|
|
if Do_Yield then
|
|
Result := sched_yield;
|
|
end if;
|
|
end Yield;
|
|
|
|
------------------
|
|
-- Set_Priority --
|
|
------------------
|
|
|
|
procedure Set_Priority
|
|
(T : Task_Id;
|
|
Prio : System.Any_Priority;
|
|
Loss_Of_Inheritance : Boolean := False)
|
|
is
|
|
pragma Unreferenced (Loss_Of_Inheritance);
|
|
|
|
Result : Interfaces.C.int;
|
|
Param : aliased struct_sched_param;
|
|
|
|
Priority_Specific_Policy : constant Character := Get_Policy (Prio);
|
|
-- Upper case first character of the policy name corresponding to the
|
|
-- task as set by a Priority_Specific_Dispatching pragma.
|
|
|
|
begin
|
|
T.Common.Current_Priority := Prio;
|
|
Param.sched_priority := Interfaces.C.int (Underlying_Priorities (Prio));
|
|
|
|
if Dispatching_Policy = 'R'
|
|
or else Priority_Specific_Policy = 'R'
|
|
or else Time_Slice_Val > 0
|
|
then
|
|
Result :=
|
|
pthread_setschedparam
|
|
(T.Common.LL.Thread, SCHED_RR, Param'Access);
|
|
|
|
elsif Dispatching_Policy = 'F'
|
|
or else Priority_Specific_Policy = 'F'
|
|
or else Time_Slice_Val = 0
|
|
then
|
|
Result :=
|
|
pthread_setschedparam
|
|
(T.Common.LL.Thread, SCHED_FIFO, Param'Access);
|
|
|
|
else
|
|
Result :=
|
|
pthread_setschedparam
|
|
(T.Common.LL.Thread, SCHED_OTHER, Param'Access);
|
|
end if;
|
|
|
|
pragma Assert (Result = 0);
|
|
end Set_Priority;
|
|
|
|
------------------
|
|
-- Get_Priority --
|
|
------------------
|
|
|
|
function Get_Priority (T : Task_Id) return System.Any_Priority is
|
|
begin
|
|
return T.Common.Current_Priority;
|
|
end Get_Priority;
|
|
|
|
----------------
|
|
-- Enter_Task --
|
|
----------------
|
|
|
|
procedure Enter_Task (Self_ID : Task_Id) is
|
|
begin
|
|
Hide_Unhide_Yellow_Zone (Hide => True);
|
|
Self_ID.Common.LL.Thread := pthread_self;
|
|
|
|
Specific.Set (Self_ID);
|
|
end Enter_Task;
|
|
|
|
--------------
|
|
-- New_ATCB --
|
|
--------------
|
|
|
|
function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
|
|
begin
|
|
return new Ada_Task_Control_Block (Entry_Num);
|
|
end New_ATCB;
|
|
|
|
-------------------
|
|
-- Is_Valid_Task --
|
|
-------------------
|
|
|
|
function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
|
|
|
|
-----------------------------
|
|
-- Register_Foreign_Thread --
|
|
-----------------------------
|
|
|
|
function Register_Foreign_Thread return Task_Id is
|
|
begin
|
|
if Is_Valid_Task then
|
|
return Self;
|
|
else
|
|
return Register_Foreign_Thread (pthread_self);
|
|
end if;
|
|
end Register_Foreign_Thread;
|
|
|
|
--------------------
|
|
-- Initialize_TCB --
|
|
--------------------
|
|
|
|
procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
|
|
Mutex_Attr : aliased pthread_mutexattr_t;
|
|
Result : Interfaces.C.int;
|
|
Cond_Attr : aliased pthread_condattr_t;
|
|
|
|
begin
|
|
if not Single_Lock then
|
|
Result := pthread_mutexattr_init (Mutex_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result = 0 then
|
|
Result :=
|
|
pthread_mutex_init
|
|
(Self_ID.Common.LL.L'Access, Mutex_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
end if;
|
|
|
|
if Result /= 0 then
|
|
Succeeded := False;
|
|
return;
|
|
end if;
|
|
|
|
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
|
|
Result := pthread_condattr_init (Cond_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result = 0 then
|
|
Result :=
|
|
pthread_cond_init
|
|
(Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
end if;
|
|
|
|
if Result = 0 then
|
|
Succeeded := True;
|
|
else
|
|
if not Single_Lock then
|
|
Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
|
|
Succeeded := False;
|
|
end if;
|
|
|
|
Result := pthread_condattr_destroy (Cond_Attr'Access);
|
|
pragma Assert (Result = 0);
|
|
end Initialize_TCB;
|
|
|
|
-----------------
|
|
-- Create_Task --
|
|
-----------------
|
|
|
|
procedure Create_Task
|
|
(T : Task_Id;
|
|
Wrapper : System.Address;
|
|
Stack_Size : System.Parameters.Size_Type;
|
|
Priority : System.Any_Priority;
|
|
Succeeded : out Boolean)
|
|
is
|
|
Attributes : aliased pthread_attr_t;
|
|
Adjusted_Stack_Size : Interfaces.C.size_t;
|
|
Result : Interfaces.C.int;
|
|
Param : aliased System.OS_Interface.struct_sched_param;
|
|
|
|
Priority_Specific_Policy : constant Character := Get_Policy (Priority);
|
|
-- Upper case first character of the policy name corresponding to the
|
|
-- task as set by a Priority_Specific_Dispatching pragma.
|
|
|
|
use System.Task_Info;
|
|
|
|
begin
|
|
-- Account for the Yellow Zone (2 pages) and the guard page right above.
|
|
-- See Hide_Unhide_Yellow_Zone for the rationale.
|
|
|
|
Adjusted_Stack_Size :=
|
|
Interfaces.C.size_t (Stack_Size) + 3 * Get_Page_Size;
|
|
|
|
Result := pthread_attr_init (Attributes'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result /= 0 then
|
|
Succeeded := False;
|
|
return;
|
|
end if;
|
|
|
|
Result :=
|
|
pthread_attr_setdetachstate
|
|
(Attributes'Access, PTHREAD_CREATE_DETACHED);
|
|
pragma Assert (Result = 0);
|
|
|
|
Result :=
|
|
pthread_attr_setstacksize
|
|
(Attributes'Access, Adjusted_Stack_Size);
|
|
pragma Assert (Result = 0);
|
|
|
|
Param.sched_priority :=
|
|
Interfaces.C.int (Underlying_Priorities (Priority));
|
|
Result :=
|
|
pthread_attr_setschedparam
|
|
(Attributes'Access, Param'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
if Dispatching_Policy = 'R'
|
|
or else Priority_Specific_Policy = 'R'
|
|
or else Time_Slice_Val > 0
|
|
then
|
|
Result :=
|
|
pthread_attr_setschedpolicy
|
|
(Attributes'Access, System.OS_Interface.SCHED_RR);
|
|
|
|
elsif Dispatching_Policy = 'F'
|
|
or else Priority_Specific_Policy = 'F'
|
|
or else Time_Slice_Val = 0
|
|
then
|
|
Result :=
|
|
pthread_attr_setschedpolicy
|
|
(Attributes'Access, System.OS_Interface.SCHED_FIFO);
|
|
|
|
else
|
|
Result :=
|
|
pthread_attr_setschedpolicy
|
|
(Attributes'Access, System.OS_Interface.SCHED_OTHER);
|
|
end if;
|
|
|
|
pragma Assert (Result = 0);
|
|
|
|
-- Set the scheduling parameters explicitly, since this is the only way
|
|
-- to force the OS to take e.g. the sched policy and scope attributes
|
|
-- into account.
|
|
|
|
Result :=
|
|
pthread_attr_setinheritsched
|
|
(Attributes'Access, PTHREAD_EXPLICIT_SCHED);
|
|
pragma Assert (Result = 0);
|
|
|
|
T.Common.Current_Priority := Priority;
|
|
|
|
if T.Common.Task_Info /= null then
|
|
case T.Common.Task_Info.Contention_Scope is
|
|
when System.Task_Info.Process_Scope =>
|
|
Result :=
|
|
pthread_attr_setscope
|
|
(Attributes'Access, PTHREAD_SCOPE_PROCESS);
|
|
|
|
when System.Task_Info.System_Scope =>
|
|
Result :=
|
|
pthread_attr_setscope
|
|
(Attributes'Access, PTHREAD_SCOPE_SYSTEM);
|
|
|
|
when System.Task_Info.Default_Scope =>
|
|
Result := 0;
|
|
end case;
|
|
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
|
|
-- Since the initial signal mask of a thread is inherited from the
|
|
-- creator, and the Environment task has all its signals masked, we
|
|
-- do not need to manipulate caller's signal mask at this point.
|
|
-- All tasks in RTS will have All_Tasks_Mask initially.
|
|
|
|
Result :=
|
|
pthread_create
|
|
(T.Common.LL.Thread'Access,
|
|
Attributes'Access,
|
|
Thread_Body_Access (Wrapper),
|
|
To_Address (T));
|
|
pragma Assert (Result = 0 or else Result = EAGAIN);
|
|
|
|
Succeeded := Result = 0;
|
|
|
|
Result := pthread_attr_destroy (Attributes'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
if Succeeded and then T.Common.Task_Info /= null then
|
|
|
|
-- ??? We're using a process-wide function to implement a task
|
|
-- specific characteristic.
|
|
|
|
if T.Common.Task_Info.Bind_To_Cpu_Number = 0 then
|
|
Result := bind_to_cpu (Curpid, 0);
|
|
|
|
elsif T.Common.Task_Info.Bind_To_Cpu_Number > 0 then
|
|
Result :=
|
|
bind_to_cpu
|
|
(Curpid,
|
|
Interfaces.C.unsigned_long (
|
|
Interfaces.Shift_Left
|
|
(Interfaces.Unsigned_64'(1),
|
|
T.Common.Task_Info.Bind_To_Cpu_Number - 1)));
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
end if;
|
|
end Create_Task;
|
|
|
|
------------------
|
|
-- Finalize_TCB --
|
|
------------------
|
|
|
|
procedure Finalize_TCB (T : Task_Id) is
|
|
Result : Interfaces.C.int;
|
|
Tmp : Task_Id := T;
|
|
Is_Self : constant Boolean := T = Self;
|
|
|
|
procedure Free is new
|
|
Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
|
|
|
|
begin
|
|
if not Single_Lock then
|
|
Result := pthread_mutex_destroy (T.Common.LL.L'Access);
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
|
|
Result := pthread_cond_destroy (T.Common.LL.CV'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
if T.Known_Tasks_Index /= -1 then
|
|
Known_Tasks (T.Known_Tasks_Index) := null;
|
|
end if;
|
|
|
|
Free (Tmp);
|
|
|
|
if Is_Self then
|
|
Specific.Set (null);
|
|
end if;
|
|
end Finalize_TCB;
|
|
|
|
---------------
|
|
-- Exit_Task --
|
|
---------------
|
|
|
|
procedure Exit_Task is
|
|
begin
|
|
Specific.Set (null);
|
|
Hide_Unhide_Yellow_Zone (Hide => False);
|
|
end Exit_Task;
|
|
|
|
----------------
|
|
-- Abort_Task --
|
|
----------------
|
|
|
|
procedure Abort_Task (T : Task_Id) is
|
|
Result : Interfaces.C.int;
|
|
begin
|
|
if Abort_Handler_Installed then
|
|
Result := pthread_kill (T.Common.LL.Thread,
|
|
Signal (System.Interrupt_Management.Abort_Task_Interrupt));
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
end Abort_Task;
|
|
|
|
----------------
|
|
-- Initialize --
|
|
----------------
|
|
|
|
procedure Initialize (S : in out Suspension_Object) is
|
|
Mutex_Attr : aliased pthread_mutexattr_t;
|
|
Cond_Attr : aliased pthread_condattr_t;
|
|
Result : Interfaces.C.int;
|
|
|
|
begin
|
|
-- Initialize internal state (always to False (RM D.10(6)))
|
|
|
|
S.State := False;
|
|
S.Waiting := False;
|
|
|
|
-- Initialize internal mutex
|
|
|
|
Result := pthread_mutexattr_init (Mutex_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result = ENOMEM then
|
|
raise Storage_Error;
|
|
end if;
|
|
|
|
Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result = ENOMEM then
|
|
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
|
|
raise Storage_Error;
|
|
end if;
|
|
|
|
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
-- Initialize internal condition variable
|
|
|
|
Result := pthread_condattr_init (Cond_Attr'Access);
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
|
|
|
|
pragma Assert (Result = 0 or else Result = ENOMEM);
|
|
|
|
if Result /= 0 then
|
|
Result := pthread_mutex_destroy (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
if Result = ENOMEM then
|
|
raise Storage_Error;
|
|
end if;
|
|
end if;
|
|
end Initialize;
|
|
|
|
--------------
|
|
-- Finalize --
|
|
--------------
|
|
|
|
procedure Finalize (S : in out Suspension_Object) is
|
|
Result : Interfaces.C.int;
|
|
|
|
begin
|
|
-- Destroy internal mutex
|
|
|
|
Result := pthread_mutex_destroy (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
-- Destroy internal condition variable
|
|
|
|
Result := pthread_cond_destroy (S.CV'Access);
|
|
pragma Assert (Result = 0);
|
|
end Finalize;
|
|
|
|
-------------------
|
|
-- Current_State --
|
|
-------------------
|
|
|
|
function Current_State (S : Suspension_Object) return Boolean is
|
|
begin
|
|
-- We do not want to use lock on this read operation. State is marked
|
|
-- as Atomic so that we ensure that the value retrieved is correct.
|
|
|
|
return S.State;
|
|
end Current_State;
|
|
|
|
---------------
|
|
-- Set_False --
|
|
---------------
|
|
|
|
procedure Set_False (S : in out Suspension_Object) is
|
|
Result : Interfaces.C.int;
|
|
|
|
begin
|
|
SSL.Abort_Defer.all;
|
|
|
|
Result := pthread_mutex_lock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
S.State := False;
|
|
|
|
Result := pthread_mutex_unlock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
SSL.Abort_Undefer.all;
|
|
end Set_False;
|
|
|
|
--------------
|
|
-- Set_True --
|
|
--------------
|
|
|
|
procedure Set_True (S : in out Suspension_Object) is
|
|
Result : Interfaces.C.int;
|
|
|
|
begin
|
|
SSL.Abort_Defer.all;
|
|
|
|
Result := pthread_mutex_lock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
-- If there is already a task waiting on this suspension object then we
|
|
-- resume it, leaving the state of the suspension object to False, as
|
|
-- specified in (RM D.10(9)). Otherwise, leave the state set to True.
|
|
|
|
if S.Waiting then
|
|
S.Waiting := False;
|
|
S.State := False;
|
|
|
|
Result := pthread_cond_signal (S.CV'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
else
|
|
S.State := True;
|
|
end if;
|
|
|
|
Result := pthread_mutex_unlock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
SSL.Abort_Undefer.all;
|
|
end Set_True;
|
|
|
|
------------------------
|
|
-- Suspend_Until_True --
|
|
------------------------
|
|
|
|
procedure Suspend_Until_True (S : in out Suspension_Object) is
|
|
Result : Interfaces.C.int;
|
|
|
|
begin
|
|
SSL.Abort_Defer.all;
|
|
|
|
Result := pthread_mutex_lock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
if S.Waiting then
|
|
|
|
-- Program_Error must be raised upon calling Suspend_Until_True
|
|
-- if another task is already waiting on that suspension object
|
|
-- (AM D.10(10)).
|
|
|
|
Result := pthread_mutex_unlock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
SSL.Abort_Undefer.all;
|
|
|
|
raise Program_Error;
|
|
|
|
else
|
|
-- Suspend the task if the state is False. Otherwise, the task
|
|
-- continues its execution, and the state of the suspension object
|
|
-- is set to False (RM D.10(9)).
|
|
|
|
if S.State then
|
|
S.State := False;
|
|
else
|
|
S.Waiting := True;
|
|
|
|
loop
|
|
-- Loop in case pthread_cond_wait returns earlier than expected
|
|
-- (e.g. in case of EINTR caused by a signal).
|
|
|
|
Result := pthread_cond_wait (S.CV'Access, S.L'Access);
|
|
pragma Assert (Result = 0 or else Result = EINTR);
|
|
|
|
exit when not S.Waiting;
|
|
end loop;
|
|
end if;
|
|
|
|
Result := pthread_mutex_unlock (S.L'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
SSL.Abort_Undefer.all;
|
|
end if;
|
|
end Suspend_Until_True;
|
|
|
|
----------------
|
|
-- Check_Exit --
|
|
----------------
|
|
|
|
-- Dummy version
|
|
|
|
function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
|
|
pragma Unreferenced (Self_ID);
|
|
begin
|
|
return True;
|
|
end Check_Exit;
|
|
|
|
--------------------
|
|
-- Check_No_Locks --
|
|
--------------------
|
|
|
|
function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
|
|
pragma Unreferenced (Self_ID);
|
|
begin
|
|
return True;
|
|
end Check_No_Locks;
|
|
|
|
----------------------
|
|
-- Environment_Task --
|
|
----------------------
|
|
|
|
function Environment_Task return Task_Id is
|
|
begin
|
|
return Environment_Task_Id;
|
|
end Environment_Task;
|
|
|
|
--------------
|
|
-- Lock_RTS --
|
|
--------------
|
|
|
|
procedure Lock_RTS is
|
|
begin
|
|
Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
|
|
end Lock_RTS;
|
|
|
|
----------------
|
|
-- Unlock_RTS --
|
|
----------------
|
|
|
|
procedure Unlock_RTS is
|
|
begin
|
|
Unlock (Single_RTS_Lock'Access, Global_Lock => True);
|
|
end Unlock_RTS;
|
|
|
|
------------------
|
|
-- Suspend_Task --
|
|
------------------
|
|
|
|
function Suspend_Task
|
|
(T : ST.Task_Id;
|
|
Thread_Self : Thread_Id) return Boolean
|
|
is
|
|
pragma Unreferenced (T, Thread_Self);
|
|
begin
|
|
return False;
|
|
end Suspend_Task;
|
|
|
|
-----------------
|
|
-- Resume_Task --
|
|
-----------------
|
|
|
|
function Resume_Task
|
|
(T : ST.Task_Id;
|
|
Thread_Self : Thread_Id) return Boolean
|
|
is
|
|
pragma Unreferenced (T, Thread_Self);
|
|
begin
|
|
return False;
|
|
end Resume_Task;
|
|
|
|
--------------------
|
|
-- Stop_All_Tasks --
|
|
--------------------
|
|
|
|
procedure Stop_All_Tasks is
|
|
begin
|
|
null;
|
|
end Stop_All_Tasks;
|
|
|
|
---------------
|
|
-- Stop_Task --
|
|
---------------
|
|
|
|
function Stop_Task (T : ST.Task_Id) return Boolean is
|
|
pragma Unreferenced (T);
|
|
begin
|
|
return False;
|
|
end Stop_Task;
|
|
|
|
-------------------
|
|
-- Continue_Task --
|
|
-------------------
|
|
|
|
function Continue_Task (T : ST.Task_Id) return Boolean is
|
|
pragma Unreferenced (T);
|
|
begin
|
|
return False;
|
|
end Continue_Task;
|
|
|
|
----------------
|
|
-- Initialize --
|
|
----------------
|
|
|
|
procedure Initialize (Environment_Task : Task_Id) is
|
|
act : aliased struct_sigaction;
|
|
old_act : aliased struct_sigaction;
|
|
Tmp_Set : aliased sigset_t;
|
|
Result : Interfaces.C.int;
|
|
|
|
function State
|
|
(Int : System.Interrupt_Management.Interrupt_ID) return Character;
|
|
pragma Import (C, State, "__gnat_get_interrupt_state");
|
|
-- Get interrupt state. Defined in a-init.c. The input argument is
|
|
-- the interrupt number, and the result is one of the following:
|
|
|
|
Default : constant Character := 's';
|
|
-- 'n' this interrupt not set by any Interrupt_State pragma
|
|
-- 'u' Interrupt_State pragma set state to User
|
|
-- 'r' Interrupt_State pragma set state to Runtime
|
|
-- 's' Interrupt_State pragma set state to System (use "default"
|
|
-- system handler)
|
|
|
|
begin
|
|
Environment_Task_Id := Environment_Task;
|
|
|
|
Interrupt_Management.Initialize;
|
|
|
|
-- Prepare the set of signals that should unblocked in all tasks
|
|
|
|
Result := sigemptyset (Unblocked_Signal_Mask'Access);
|
|
pragma Assert (Result = 0);
|
|
|
|
for J in Interrupt_Management.Interrupt_ID loop
|
|
if System.Interrupt_Management.Keep_Unmasked (J) then
|
|
Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
|
|
pragma Assert (Result = 0);
|
|
end if;
|
|
end loop;
|
|
|
|
Curpid := getpid;
|
|
|
|
-- Initialize the lock used to synchronize chain of all ATCBs
|
|
|
|
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
|
|
|
|
Specific.Initialize (Environment_Task);
|
|
|
|
-- Make environment task known here because it doesn't go through
|
|
-- Activate_Tasks, which does it for all other tasks.
|
|
|
|
Known_Tasks (Known_Tasks'First) := Environment_Task;
|
|
Environment_Task.Known_Tasks_Index := Known_Tasks'First;
|
|
|
|
Enter_Task (Environment_Task);
|
|
|
|
if State
|
|
(System.Interrupt_Management.Abort_Task_Interrupt) /= Default
|
|
then
|
|
act.sa_flags := 0;
|
|
act.sa_handler := Abort_Handler'Address;
|
|
|
|
Result := sigemptyset (Tmp_Set'Access);
|
|
pragma Assert (Result = 0);
|
|
act.sa_mask := Tmp_Set;
|
|
|
|
Result :=
|
|
sigaction
|
|
(Signal (System.Interrupt_Management.Abort_Task_Interrupt),
|
|
act'Unchecked_Access,
|
|
old_act'Unchecked_Access);
|
|
pragma Assert (Result = 0);
|
|
Abort_Handler_Installed := True;
|
|
end if;
|
|
end Initialize;
|
|
|
|
end System.Task_Primitives.Operations;
|