File : s-taprop.adb
------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- 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 --
-- --
-- B o d y --
-- --
-- $Revision: 1.59 $
-- --
-- Copyright (C) 1992-1999, Free Software Foundation, Inc. --
-- --
-- GNARL 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 2, or (at your option) any later ver- --
-- sion. GNARL 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNARL; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This is a NT (native) version of this package.
-- This package contains all the GNULL primitives that interface directly
-- with the underlying OS.
pragma Polling (Off);
-- Turn off polling, we do not want ATC polling to take place during
-- tasking operations. It causes infinite loops and other problems.
with System.Tasking.Debug;
-- used for Known_Tasks
with Interfaces.C;
-- used for int
-- size_t
with Interfaces.C.Strings;
-- used for Null_Ptr
with System.OS_Interface;
-- used for various type, constant, and operations
with System.Parameters;
-- used for Size_Type
with System.Tasking;
-- used for Ada_Task_Control_Block
-- Task_ID
with System.Soft_Links;
-- used for Defer/Undefer_Abort
-- to initialize TSD for a C thread, in function Self
-- Note that we do not use System.Tasking.Initialization directly since
-- this is a higher level package that we shouldn't depend on. For example
-- when using the restricted run time, it is replaced by
-- System.Tasking.Restricted.Initialization
with System.OS_Primitives;
-- used for Delay_Modes
with System.Task_Info;
-- used for Unspecified_Task_Info
with Unchecked_Conversion;
with Unchecked_Deallocation;
package body System.Task_Primitives.Operations is
use System.Tasking.Debug;
use System.Tasking;
use Interfaces.C;
use Interfaces.C.Strings;
use System.OS_Interface;
use System.Parameters;
use System.OS_Primitives;
package TSL renames System.Soft_Links;
------------------
-- Local Data --
------------------
Environment_Task_ID : Task_ID;
-- A variable to hold Task_ID for the environment task.
All_Tasks_L : aliased System.Task_Primitives.RTS_Lock;
-- See comments on locking rules in System.Tasking (spec).
Task_Dispatching_Policy : Character;
pragma Import (C, Task_Dispatching_Policy, "__gl_task_dispatching_policy");
Time_Slice_Val : Integer;
pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
FIFO_Emulation : constant Boolean := Task_Dispatching_Policy = 'F';
-- Indicates whether FIFO_Within_Priorities is being emulated.
---------------------------------
-- Foreign Threads Detection --
---------------------------------
-- The following are used to allow the Self function to
-- automatically generate ATCB's for C threads that happen to call
-- Ada procedure, which in turn happen to call the Ada run-time system.
type Fake_ATCB;
type Fake_ATCB_Ptr is access Fake_ATCB;
type Fake_ATCB is record
Stack_Base : Interfaces.C.unsigned := 0;
-- A value of zero indicates the node is not in use.
Next : Fake_ATCB_Ptr;
Real_ATCB : aliased Ada_Task_Control_Block (0);
end record;
Fake_ATCB_List : Fake_ATCB_Ptr;
-- A linear linked list.
-- The list is protected by All_Tasks_L;
-- Nodes are added to this list from the front.
-- Once a node is added to this list, it is never removed.
Fake_Task_Elaborated : aliased Boolean := True;
-- Used to identified fake tasks (i.e., non-Ada Threads).
Next_Fake_ATCB : Fake_ATCB_Ptr;
-- Used to allocate one Fake_ATCB in advance. See comment in New_Fake_ATCB
---------------------------------
-- Support for New_Fake_ATCB --
---------------------------------
function New_Fake_ATCB return Task_ID;
-- Allocate and Initialize a new ATCB. This code can safely be called from
-- a foreign thread, as it doesn't access implicitely or explicitely
-- "self" before having initialized the new ATCB.
------------------------------------
-- The thread local storage index --
------------------------------------
TlsIndex : DWORD;
pragma Export (Ada, TlsIndex);
-- To ensure that this variable won't be local to this package, since
-- in some cases, inlining forces this variable to be global anyway.
----------------------------------
-- Utility Conversion Functions --
----------------------------------
function To_Task_Id is new Unchecked_Conversion (System.Address, Task_ID);
function To_Address is new Unchecked_Conversion (Task_ID, System.Address);
-------------------
-- New_Fake_ATCB --
-------------------
function New_Fake_ATCB return Task_ID is
Self_ID : Task_ID;
P, Q : Fake_ATCB_Ptr;
Succeeded : Boolean;
Res : BOOL;
begin
-- This section is ticklish.
-- We dare not call anything that might require an ATCB, until
-- we have the new ATCB in place.
Write_Lock (All_Tasks_L'Access);
Q := null;
P := Fake_ATCB_List;
while P /= null loop
if P.Stack_Base = 0 then
Q := P;
end if;
P := P.Next;
end loop;
if Q = null then
-- Create a new ATCB with zero entries.
Self_ID := Next_Fake_ATCB.Real_ATCB'Access;
Next_Fake_ATCB.Stack_Base := 1;
Next_Fake_ATCB.Next := Fake_ATCB_List;
Fake_ATCB_List := Next_Fake_ATCB;
Next_Fake_ATCB := null;
else
-- Reuse an existing fake ATCB.
Self_ID := Q.Real_ATCB'Access;
Q.Stack_Base := 1;
end if;
-- Record this as the Task_ID for the current thread.
Self_ID.LL.Thread := GetCurrentThread;
Res := TlsSetValue (TlsIndex, To_Address (Self_ID));
pragma Assert (Res = True);
-- Do the standard initializations
System.Tasking.Initialize_ATCB
(Self_ID, null, Null_Address, Null_Task, Fake_Task_Elaborated'Access,
System.Priority'First, Task_Info.Unspecified_Task_Info, 0, 0, Self_ID,
Succeeded);
pragma Assert (Succeeded);
-- Finally, it is safe to use an allocator in this thread.
if Next_Fake_ATCB = null then
Next_Fake_ATCB := new Fake_ATCB;
end if;
Self_ID.State := Runnable;
Self_ID.Awake_Count := 1;
-- Since this is not an ordinary Ada task, we will start out undeferred
Self_ID.Deferral_Level := 0;
System.Soft_Links.Create_TSD (Self_ID.Compiler_Data);
-- ????
-- The following call is commented out to avoid dependence on
-- the System.Tasking.Initialization package.
-- It seems that if we want Ada.Task_Attributes to work correctly
-- for C threads we will need to raise the visibility of this soft
-- link to System.Soft_Links.
-- We are putting that off until this new functionality is otherwise
-- stable.
-- System.Tasking.Initialization.Initialize_Attributes_Link.all (T);
-- Must not unlock until Next_ATCB is again allocated.
Unlock (All_Tasks_L'Access);
return Self_ID;
end New_Fake_ATCB;
----------------------------------
-- Condition Variable Functions --
----------------------------------
procedure Initialize_Cond (Cond : access Condition_Variable);
-- Initialize given condition variable Cond
procedure Finalize_Cond (Cond : access Condition_Variable);
-- Finalize given condition variable Cond.
procedure Cond_Signal (Cond : access Condition_Variable);
-- Signal condition variable Cond
procedure Cond_Wait
(Cond : access Condition_Variable;
L : access RTS_Lock);
-- Wait on conditional variable Cond, using lock L
procedure Cond_Timed_Wait
(Cond : access Condition_Variable;
L : access RTS_Lock;
Rel_Time : Duration;
Timed_Out : out Boolean;
Status : out Integer);
-- Do timed wait on condition variable Cond using lock L. The duration
-- of the timed wait is given by Rel_Time. When the condition is
-- signalled, Timed_Out shows whether or not a time out occurred.
-- Status shows whether Cond_Timed_Wait completed successfully.
---------------------
-- Initialize_Cond --
---------------------
procedure Initialize_Cond (Cond : access Condition_Variable) is
hEvent : HANDLE;
begin
hEvent := CreateEvent (null, True, False, Null_Ptr);
pragma Assert (hEvent /= 0);
Cond.all := Condition_Variable (hEvent);
end Initialize_Cond;
-------------------
-- Finalize_Cond --
-------------------
-- No such problem here, DosCloseEventSem has been derived.
-- What does such refer to in above comment???
procedure Finalize_Cond (Cond : access Condition_Variable) is
Result : BOOL;
begin
Result := CloseHandle (HANDLE (Cond.all));
pragma Assert (Result = True);
end Finalize_Cond;
-----------------
-- Cond_Signal --
-----------------
procedure Cond_Signal (Cond : access Condition_Variable) is
Result : BOOL;
begin
Result := SetEvent (HANDLE (Cond.all));
pragma Assert (Result = True);
end Cond_Signal;
---------------
-- Cond_Wait --
---------------
-- Pre-assertion: Cond is posted
-- L is locked.
-- Post-assertion: Cond is posted
-- L is locked.
procedure Cond_Wait
(Cond : access Condition_Variable;
L : access RTS_Lock)
is
Result : DWORD;
Result_Bool : BOOL;
begin
-- Must reset Cond BEFORE L is unlocked.
Result_Bool := ResetEvent (HANDLE (Cond.all));
pragma Assert (Result_Bool = True);
Unlock (L);
-- No problem if we are interrupted here: if the condition is signaled,
-- WaitForSingleObject will simply not block
Result := WaitForSingleObject (HANDLE (Cond.all), Wait_Infinite);
pragma Assert (Result = 0);
Write_Lock (L);
end Cond_Wait;
---------------------
-- Cond_Timed_Wait --
---------------------
-- Pre-assertion: Cond is posted
-- L is locked.
-- Post-assertion: Cond is posted
-- L is locked.
procedure Cond_Timed_Wait
(Cond : access Condition_Variable;
L : access RTS_Lock;
Rel_Time : Duration;
Timed_Out : out Boolean;
Status : out Integer)
is
Time_Out : DWORD;
Result : BOOL;
Int_Rel_Time : DWORD;
Wait_Result : DWORD;
begin
-- Must reset Cond BEFORE L is unlocked.
Result := ResetEvent (HANDLE (Cond.all));
pragma Assert (Result = True);
Unlock (L);
-- No problem if we are interrupted here: if the condition is signaled,
-- WaitForSingleObject will simply not block
if Rel_Time <= 0.0 then
Timed_Out := True;
else
Int_Rel_Time := DWORD (Rel_Time);
Time_Out := Int_Rel_Time * 1000 +
DWORD ((Rel_Time - Duration (Int_Rel_Time)) * 1000.0);
Wait_Result := WaitForSingleObject (HANDLE (Cond.all), Time_Out);
if Wait_Result = WAIT_TIMEOUT then
Timed_Out := True;
Wait_Result := 0;
else
Timed_Out := False;
end if;
end if;
Write_Lock (L);
-- Ensure post-condition
if Timed_Out then
Result := SetEvent (HANDLE (Cond.all));
pragma Assert (Result = True);
end if;
Status := Integer (Wait_Result);
end Cond_Timed_Wait;
------------------
-- Stack_Guard --
------------------
-- The underlying thread system sets a guard page at the
-- bottom of a thread stack, so nothing is needed.
-- ??? Check the comment above
procedure Stack_Guard (T : ST.Task_ID; On : Boolean) is
begin
null;
end Stack_Guard;
--------------------
-- Get_Thread_Id --
--------------------
function Get_Thread_Id (T : ST.Task_ID) return OSI.Thread_Id is
begin
return T.LL.Thread;
end Get_Thread_Id;
----------
-- Self --
----------
function Self return Task_ID is
Self_Id : Task_ID;
begin
Self_Id := To_Task_Id (TlsGetValue (TlsIndex));
if Self_Id = null then
return New_Fake_ATCB;
end if;
return Self_Id;
end Self;
---------------------
-- Initialize_Lock --
---------------------
-- Note: mutexes and cond_variables needed per-task basis are
-- initialized in Intialize_TCB and the Storage_Error is handled.
-- Other mutexes (such as All_Tasks_Lock, Memory_Lock...) used in
-- the RTS is initialized before any status change of RTS.
-- Therefore raising Storage_Error in the following routines
-- should be able to be handled safely.
procedure Initialize_Lock
(Prio : System.Any_Priority;
L : access Lock) is
begin
InitializeCriticalSection (L.Mutex'Access);
L.Owner_Priority := 0;
L.Priority := Prio;
end Initialize_Lock;
procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
begin
InitializeCriticalSection (CRITICAL_SECTION (L.all)'Unrestricted_Access);
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : access Lock) is
begin
DeleteCriticalSection (L.Mutex'Access);
end Finalize_Lock;
procedure Finalize_Lock (L : access RTS_Lock) is
begin
DeleteCriticalSection (CRITICAL_SECTION (L.all)'Unrestricted_Access);
end Finalize_Lock;
----------------
-- Write_Lock --
----------------
procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
begin
L.Owner_Priority := Get_Priority (Self);
if L.Priority < L.Owner_Priority then
Ceiling_Violation := True;
return;
end if;
EnterCriticalSection (L.Mutex'Access);
Ceiling_Violation := False;
end Write_Lock;
procedure Write_Lock (L : access RTS_Lock) is
begin
EnterCriticalSection (CRITICAL_SECTION (L.all)'Unrestricted_Access);
end Write_Lock;
procedure Write_Lock (T : Task_ID) is
begin
EnterCriticalSection (CRITICAL_SECTION (T.LL.L)'Unrestricted_Access);
end Write_Lock;
---------------
-- Read_Lock --
---------------
procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
begin
Write_Lock (L, Ceiling_Violation);
end Read_Lock;
------------
-- Unlock --
------------
procedure Unlock (L : access Lock) is
begin
LeaveCriticalSection (L.Mutex'Access);
end Unlock;
procedure Unlock (L : access RTS_Lock) is
begin
LeaveCriticalSection (CRITICAL_SECTION (L.all)'Unrestricted_Access);
end Unlock;
procedure Unlock (T : Task_ID) is
begin
LeaveCriticalSection (CRITICAL_SECTION (T.LL.L)'Unrestricted_Access);
end Unlock;
-----------
-- Sleep --
-----------
procedure Sleep
(Self_ID : Task_ID;
Reason : System.Tasking.Task_States) is
begin
pragma Assert (Self_ID = Self);
Cond_Wait (Self_ID.LL.CV'Access, Self_ID.LL.L'Access);
if Self_ID.Deferral_Level = 0
and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
then
Unlock (Self_ID);
raise Standard'Abort_Signal;
end if;
end Sleep;
-----------------
-- Timed_Sleep --
-----------------
-- This is for use within the run-time system, so abort is
-- assumed to be already deferred, and the caller should be
-- holding its own ATCB lock.
procedure Timed_Sleep
(Self_ID : Task_ID;
Time : Duration;
Mode : ST.Delay_Modes;
Reason : System.Tasking.Task_States;
Timedout : out Boolean;
Yielded : out Boolean)
is
Check_Time : constant Duration := Clock;
Rel_Time : Duration;
Abs_Time : Duration;
Result : Integer;
Local_Timedout : Boolean;
begin
Timedout := True;
Yielded := False;
if Mode = Relative then
Rel_Time := Time;
Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
else
Rel_Time := Time - Check_Time;
Abs_Time := Time;
end if;
if Rel_Time > 0.0 then
loop
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
or else Self_ID.Pending_Priority_Change;
Cond_Timed_Wait
(Self_ID.LL.CV'Access, Self_ID.LL.L'Access, Rel_Time,
Local_Timedout, Result);
exit when Abs_Time <= Clock;
if not Local_Timedout then
-- somebody may have called Wakeup for us
Timedout := False;
exit;
end if;
Rel_Time := Abs_Time - Clock;
end loop;
end if;
end Timed_Sleep;
-----------------
-- Timed_Delay --
-----------------
procedure Timed_Delay
(Self_ID : Task_ID;
Time : Duration;
Mode : ST.Delay_Modes)
is
Check_Time : constant Duration := Clock;
Rel_Time : Duration;
Abs_Time : Duration;
Result : Integer;
Timedout : Boolean;
begin
-- Only the little window between deferring abort and
-- locking Self_ID is the reason we need to
-- check for pending abort and priority change below! :(
TSL.Abort_Defer.all;
Write_Lock (Self_ID);
if Mode = Relative then
Rel_Time := Time;
Abs_Time := Time + Check_Time;
else
Rel_Time := Time - Check_Time;
Abs_Time := Time;
end if;
if Rel_Time > 0.0 then
Self_ID.State := Delay_Sleep;
loop
if Self_ID.Pending_Priority_Change then
Self_ID.Pending_Priority_Change := False;
Self_ID.Base_Priority := Self_ID.New_Base_Priority;
Set_Priority (Self_ID, Self_ID.Base_Priority);
end if;
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
Cond_Timed_Wait
(Self_ID.LL.CV'Access, Self_ID.LL.L'Access, Rel_Time,
Timedout, Result);
exit when Abs_Time <= Clock;
Rel_Time := Abs_Time - Clock;
end loop;
Self_ID.State := Runnable;
end if;
Unlock (Self_ID);
Yield;
TSL.Abort_Undefer.all;
end Timed_Delay;
------------
-- Wakeup --
------------
procedure Wakeup (T : Task_ID; Reason : System.Tasking.Task_States) is
begin
Cond_Signal (T.LL.CV'Access);
end Wakeup;
-----------
-- Yield --
-----------
procedure Yield (Do_Yield : Boolean := True) is
begin
if Do_Yield then
Sleep (0);
end if;
end Yield;
------------------
-- Set_Priority --
------------------
type Prio_Array_Type is array (System.Any_Priority) of Integer;
pragma Atomic_Components (Prio_Array_Type);
Prio_Array : Prio_Array_Type;
-- Global array containing the id of the currently running task for
-- each priority.
--
-- Note: we assume that we are on a single processor with run-til-blocked
-- scheduling.
procedure Set_Priority
(T : Task_ID;
Prio : System.Any_Priority;
Loss_Of_Inheritance : Boolean := False)
is
Res : BOOL;
Array_Item : Integer;
begin
Res := SetThreadPriority
(T.LL.Thread, Interfaces.C.int (Underlying_Priorities (Prio)));
pragma Assert (Res = True);
-- ??? Work around a bug in NT 4.0 SP3 scheduler
-- It looks like when a task with Thread_Priority_Idle (using RT class)
-- never reaches its time slice (e.g by doing multiple and simple RV,
-- see CXD8002), the scheduler never gives higher priority task a
-- chance to run.
-- Note that this works fine on NT 4.0 SP1
if Time_Slice_Val = 0
and then Underlying_Priorities (Prio) = Thread_Priority_Idle
and then Loss_Of_Inheritance
then
Sleep (20);
end if;
if FIFO_Emulation then
-- Annex D requirement [RM D.2.2 par. 9]:
-- If the task drops its priority due to the loss of inherited
-- priority, it is added at the head of the ready queue for its
-- new active priority.
if Loss_Of_Inheritance
and then Prio < Any_Priority (T.LL.Current_Priority)
then
Array_Item := Prio_Array (T.Base_Priority) + 1;
Prio_Array (T.Base_Priority) := Array_Item;
loop
-- Let some processes a chance to arrive
Yield;
-- Then wait for our turn to proceed
exit when Array_Item = Prio_Array (T.Base_Priority)
or else Prio_Array (T.Base_Priority) = 1;
end loop;
Prio_Array (T.Base_Priority) := Prio_Array (T.Base_Priority) - 1;
end if;
end if;
T.LL.Current_Priority := Interfaces.C.int (Prio);
end Set_Priority;
------------------
-- Get_Priority --
------------------
function Get_Priority (T : Task_ID) return System.Any_Priority is
begin
return System.Any_Priority (T.LL.Current_Priority);
end Get_Priority;
----------------
-- Enter_Task --
----------------
-- There were two paths were we needed to call Enter_Task :
-- 1) from System.Task_Primitives.Operations.Initialize
-- 2) from System.Tasking.Stages.Task_Wrapper
--
-- The thread initialisation has to be done only for the first case.
--
-- This is because the GetCurrentThread NT call does not return the
-- real thread handler but only a "pseudo" one. It is not possible to
-- release the thread handle and free the system ressources from this
-- "pseudo" handle. So we really want to keep the real thread handle
-- set in System.Task_Primitives.Operations.Create_Task during the
-- thread creation.
procedure Enter_Task (Self_ID : Task_ID) is
procedure Init_Float;
pragma Import (C, Init_Float, "__gnat_init_float");
-- Properly initializes the FPU for x86 systems.
Succeeded : BOOL;
begin
Succeeded := TlsSetValue (TlsIndex, To_Address (Self_ID));
pragma Assert (Succeeded = True);
Init_Float;
Self_ID.LL.Thread_Id := GetCurrentThreadId;
Lock_All_Tasks_List;
for J in Known_Tasks'Range loop
if Known_Tasks (J) = null then
Known_Tasks (J) := Self_ID;
Self_ID.Known_Tasks_Index := J;
exit;
end if;
end loop;
Unlock_All_Tasks_List;
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;
----------------------
-- Initialize_TCB --
----------------------
procedure Initialize_TCB (Self_ID : Task_ID; Succeeded : out Boolean) is
begin
Initialize_Cond (Self_ID.LL.CV'Access);
Initialize_Lock (Self_ID.LL.L'Access, ATCB_Level);
Succeeded := True;
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
hTask : HANDLE;
TaskId : aliased DWORD;
-- ??? The fact that we can't use PVOID because the compiler
-- gives a "PVOID is not visible" error is a GNAT bug.
-- The strange thing is that the file compiles fine during a regular
-- build.
pTaskParameter : System.OS_Interface.PVOID;
dwStackSize : DWORD;
Result : DWORD;
Entry_Point : PTHREAD_START_ROUTINE;
function To_PTHREAD_START_ROUTINE is new
Unchecked_Conversion (System.Address, PTHREAD_START_ROUTINE);
begin
pTaskParameter := To_Address (T);
if Stack_Size = Unspecified_Size then
dwStackSize := DWORD (Default_Stack_Size);
elsif Stack_Size < Minimum_Stack_Size then
dwStackSize := DWORD (Minimum_Stack_Size);
else
dwStackSize := DWORD (Stack_Size);
end if;
Entry_Point := To_PTHREAD_START_ROUTINE (Wrapper);
hTask := CreateThread
(null,
dwStackSize,
Entry_Point,
pTaskParameter,
DWORD (Create_Suspended),
TaskId'Unchecked_Access);
-- Step 1: Create the thread in blocked mode
if hTask = 0 then
raise Storage_error;
end if;
-- Step 2: set its TCB
T.LL.Thread := hTask;
-- Step 3: set its priority (child has inherited priority from parent)
Set_Priority (T, Priority);
-- Step 4: Now, start it for good:
Result := ResumeThread (hTask);
pragma Assert (Result = 1);
Succeeded := Result = 1;
end Create_Task;
------------------
-- Finalize_TCB --
------------------
procedure Finalize_TCB (T : Task_ID) is
Self_ID : Task_ID := T;
Result : DWORD;
Succeeded : BOOL;
procedure Free is new
Unchecked_Deallocation (Ada_Task_Control_Block, Task_ID);
begin
Finalize_Lock (T.LL.L'Access);
Finalize_Cond (T.LL.CV'Access);
if T.Known_Tasks_Index /= -1 then
Known_Tasks (T.Known_Tasks_Index) := null;
end if;
-- Wait for the thread to terminate then close it. this is needed
-- to release system ressources.
Result := WaitForSingleObject (T.LL.Thread, Wait_Infinite);
pragma Assert (Result /= WAIT_FAILED);
Succeeded := CloseHandle (T.LL.Thread);
pragma Assert (Succeeded = True);
Free (Self_ID);
end Finalize_TCB;
---------------
-- Exit_Task --
---------------
procedure Exit_Task is
begin
ExitThread (0);
end Exit_Task;
----------------
-- Abort_Task --
----------------
procedure Abort_Task (T : Task_ID) is
begin
null;
end Abort_Task;
----------------------
-- Environment_Task --
----------------------
function Environment_Task return Task_ID is
begin
return Environment_Task_ID;
end Environment_Task;
-------------------------
-- Lock_All_Tasks_List --
-------------------------
procedure Lock_All_Tasks_List is
begin
Write_Lock (All_Tasks_L'Access);
end Lock_All_Tasks_List;
---------------------------
-- Unlock_All_Tasks_List --
---------------------------
procedure Unlock_All_Tasks_List is
begin
Unlock (All_Tasks_L'Access);
end Unlock_All_Tasks_List;
----------------
-- Initialize --
----------------
procedure Initialize (Environment_Task : Task_ID) is
Res : BOOL;
begin
Environment_Task_ID := Environment_Task;
if Time_Slice_Val = 0 then
Res := OS_Interface.SetPriorityClass
(GetCurrentProcess, Realtime_Priority_Class);
end if;
TlsIndex := TlsAlloc;
-- Initialize the lock used to synchronize chain of all ATCBs.
Initialize_Lock (All_Tasks_L'Access, All_Tasks_Level);
Environment_Task.LL.Thread := GetCurrentThread;
Enter_Task (Environment_Task);
-- Create a free ATCB for use on the Fake_ATCB_List
Next_Fake_ATCB := new Fake_ATCB;
end Initialize;
-----------
-- Clock --
-----------
function Clock return Duration renames System.OS_Primitives.Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration is
begin
return 0.000_001; -- 1 micro-second
end RT_Resolution;
----------------
-- Check_Exit --
----------------
-- Dummy versions. The only currently working versions is for solaris
-- (native).
function Check_Exit (Self_ID : ST.Task_ID) return Boolean is
begin
return True;
end Check_Exit;
--------------------
-- Check_No_Locks --
--------------------
function Check_No_Locks (Self_ID : ST.Task_ID) return Boolean is
begin
return True;
end Check_No_Locks;
------------------
-- Suspend_Task --
------------------
function Suspend_Task
(T : ST.Task_ID;
Thread_Self : Thread_Id) return Boolean is
begin
if T.LL.Thread /= Thread_Self then
return SuspendThread (T.LL.Thread) = NO_ERROR;
else
return True;
end if;
end Suspend_Task;
-----------------
-- Resume_Task --
-----------------
function Resume_Task
(T : ST.Task_ID;
Thread_Self : Thread_Id) return Boolean is
begin
if T.LL.Thread /= Thread_Self then
return ResumeThread (T.LL.Thread) = NO_ERROR;
else
return True;
end if;
end Resume_Task;
end System.Task_Primitives.Operations;