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|
------------------------------------------------------------------------------
-- --
-- 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 --
-- --
-- Copyright (C) 1992-2004, 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. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
-- This is a LynxOS version of this file, adapted to make
-- SCHED_FIFO and ceiling locking (Annex D compliance) work properly
-- 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 System.Task_Info;
-- used for Task_Info_Type
with Interfaces.C;
-- used for int
-- size_t
with System.Interrupt_Management;
-- used for Keep_Unmasked
-- Abort_Task_Interrupt
-- Interrupt_ID
with System.Interrupt_Management.Operations;
-- used for Set_Interrupt_Mask
-- All_Tasks_Mask
pragma Elaborate_All (System.Interrupt_Management.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
-- 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 Unchecked_Deallocation;
package body System.Task_Primitives.Operations is
use System.Tasking.Debug;
use System.Tasking;
use Interfaces.C;
use System.OS_Interface;
use System.Parameters;
use System.OS_Primitives;
package SSL renames System.Soft_Links;
----------------
-- Local Data --
----------------
-- The followings are logically constants, but need to be initialized
-- at run time.
Single_RTS_Lock : aliased RTS_Lock;
-- This is a lock to allow only one thread of control in the RTS at
-- a time; it is used to execute in mutual exclusion from all other tasks.
-- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
ATCB_Key : aliased pthread_key_t;
-- Key used to find the Ada Task_Id associated with a thread
Environment_Task_Id : Task_Id;
-- A variable to hold Task_Id for the environment task.
Locking_Policy : Character;
pragma Import (C, Locking_Policy, "__gl_locking_policy");
-- Value of the pragma Locking_Policy:
-- 'C' for Ceiling_Locking
-- 'I' for Inherit_Locking
-- ' ' for none.
Unblocked_Signal_Mask : aliased sigset_t;
-- The set of signals that should unblocked in all tasks
-- The followings are internal configuration constants needed.
Next_Serial_Number : Task_Serial_Number := 100;
-- We start at 100, to reserve some special values for
-- using in error checking.
Time_Slice_Val : Integer;
pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
Dispatching_Policy : Character;
pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
FIFO_Within_Priorities : constant Boolean := Dispatching_Policy = 'F';
-- Indicates whether FIFO_Within_Priorities is set.
Foreign_Task_Elaborated : aliased Boolean := True;
-- Used to identified fake tasks (i.e., non-Ada Threads).
--------------------
-- Local Packages --
--------------------
package Specific is
procedure Initialize (Environment_Task : Task_Id);
pragma Inline (Initialize);
-- Initialize various data needed by this package.
function Is_Valid_Task return Boolean;
pragma Inline (Is_Valid_Task);
-- Does the current thread have an ATCB?
procedure Set (Self_Id : Task_Id);
pragma Inline (Set);
-- Set the self id for the current task.
function Self return Task_Id;
pragma Inline (Self);
-- Return a pointer to the Ada Task Control Block of the calling task.
end Specific;
package body Specific is separate;
-- The body of this package is target specific.
---------------------------------
-- Support for foreign threads --
---------------------------------
function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
-- Allocate and Initialize a new ATCB for the current Thread.
function Register_Foreign_Thread
(Thread : Thread_Id) return Task_Id is separate;
-----------------------
-- Local Subprograms --
-----------------------
procedure Abort_Handler (Sig : Signal);
-- Signal handler used to implement asynchronous abort.
procedure Set_OS_Priority (T : Task_Id; Prio : System.Any_Priority);
-- This procedure calls the scheduler of the OS to set thread's priority
-------------------
-- Abort_Handler --
-------------------
procedure Abort_Handler (Sig : Signal) is
pragma Unreferenced (Sig);
T : constant Task_Id := Self;
Result : Interfaces.C.int;
Old_Set : aliased sigset_t;
begin
-- It is not safe to raise an exception when using ZCX and the GCC
-- exception handling mechanism.
if ZCX_By_Default and then GCC_ZCX_Support then
return;
end if;
if T.Deferral_Level = 0
and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
not T.Aborting
then
T.Aborting := True;
-- Make sure signals used for RTS internal purpose are unmasked
Result :=
pthread_sigmask (SIG_UNBLOCK,
Unblocked_Signal_Mask'Unchecked_Access,
Old_Set'Unchecked_Access);
pragma Assert (Result = 0);
raise Standard'Abort_Signal;
end if;
end Abort_Handler;
-----------------
-- Stack_Guard --
-----------------
procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
Guard_Page_Address : Address;
Res : Interfaces.C.int;
begin
if Stack_Base_Available then
-- Compute the guard page address
Guard_Page_Address :=
Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
if On then
Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_ON);
else
Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_OFF);
end if;
pragma Assert (Res = 0);
end if;
end Stack_Guard;
--------------------
-- Get_Thread_Id --
--------------------
function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
begin
return T.Common.LL.Thread;
end Get_Thread_Id;
----------
-- Self --
----------
function Self return Task_Id renames Specific.Self;
---------------------
-- Initialize_Lock --
---------------------
procedure Initialize_Lock
(Prio : System.Any_Priority;
L : access Lock)
is
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
begin
Result := pthread_mutexattr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
if Locking_Policy = 'C' then
L.Ceiling := Prio;
end if;
Result := pthread_mutex_init (L.Mutex'Access, Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
Result := pthread_mutexattr_destroy (Attributes'Access);
pragma Assert (Result = 0);
end Initialize_Lock;
procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
pragma Unreferenced (Level);
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
begin
Result := pthread_mutexattr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
Result := pthread_mutex_init (L, Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
Result := pthread_mutexattr_destroy (Attributes'Access);
raise Storage_Error;
end if;
Result := pthread_mutexattr_destroy (Attributes'Access);
pragma Assert (Result = 0);
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L.Mutex'Access);
pragma Assert (Result = 0);
end Finalize_Lock;
procedure Finalize_Lock (L : access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
pragma Assert (Result = 0);
end Finalize_Lock;
----------------
-- Write_Lock --
----------------
procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
Result : Interfaces.C.int;
T : constant Task_Id := Self;
begin
if Locking_Policy = 'C' then
if T.Common.Current_Priority > L.Ceiling then
Ceiling_Violation := True;
return;
end if;
L.Saved_Priority := T.Common.Current_Priority;
if T.Common.Current_Priority < L.Ceiling then
Set_OS_Priority (T, L.Ceiling);
end if;
end if;
Result := pthread_mutex_lock (L.Mutex'Access);
-- Assume that the cause of EINVAL is a priority ceiling violation
Ceiling_Violation := (Result = EINVAL);
pragma Assert (Result = 0 or else Result = EINVAL);
end Write_Lock;
-- No tricks on RTS_Locks
procedure Write_Lock
(L : access RTS_Lock; Global_Lock : Boolean := False)
is
Result : Interfaces.C.int;
begin
if not Single_Lock or else Global_Lock then
Result := pthread_mutex_lock (L);
pragma Assert (Result = 0);
end if;
end Write_Lock;
procedure Write_Lock (T : Task_Id) is
Result : Interfaces.C.int;
begin
if not Single_Lock then
Result := pthread_mutex_lock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
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
Result : Interfaces.C.int;
T : constant Task_Id := Self;
begin
Result := pthread_mutex_unlock (L.Mutex'Access);
pragma Assert (Result = 0);
if Locking_Policy = 'C' then
if T.Common.Current_Priority > L.Saved_Priority then
Set_OS_Priority (T, L.Saved_Priority);
end if;
end if;
end Unlock;
procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
Result : Interfaces.C.int;
begin
if not Single_Lock or else Global_Lock then
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
end if;
end Unlock;
procedure Unlock (T : Task_Id) is
Result : Interfaces.C.int;
begin
if not Single_Lock then
Result := pthread_mutex_unlock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
end Unlock;
-----------
-- Sleep --
-----------
procedure Sleep
(Self_ID : Task_Id;
Reason : System.Tasking.Task_States)
is
pragma Unreferenced (Reason);
Result : Interfaces.C.int;
begin
if Single_Lock then
Result := pthread_cond_wait
(Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
else
Result := pthread_cond_wait
(Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
end if;
-- EINTR is not considered a failure
pragma Assert (Result = 0 or else Result = EINTR);
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 : Task_States;
Timedout : out Boolean;
Yielded : out Boolean)
is
pragma Unreferenced (Reason);
Check_Time : constant Duration := Monotonic_Clock;
Rel_Time : Duration;
Abs_Time : Duration;
Request : aliased timespec;
Result : Interfaces.C.int;
begin
Timedout := True;
Yielded := False;
if Mode = Relative then
Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
end if;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
end if;
end if;
if Abs_Time > Check_Time then
if Relative_Timed_Wait then
Request := To_Timespec (Rel_Time);
else
Request := To_Timespec (Abs_Time);
end if;
loop
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
or else Self_ID.Pending_Priority_Change;
if Single_Lock then
Result := pthread_cond_timedwait
(Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
Request'Access);
else
Result := pthread_cond_timedwait
(Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
Request'Access);
end if;
exit when Abs_Time <= Monotonic_Clock;
if Result = 0 or Result = EINTR then
-- Somebody may have called Wakeup for us
Timedout := False;
exit;
end if;
pragma Assert (Result = ETIMEDOUT);
end loop;
end if;
end Timed_Sleep;
-----------------
-- Timed_Delay --
-----------------
-- This is for use in implementing delay statements, so we assume
-- the caller is abort-deferred but is holding no locks.
procedure Timed_Delay
(Self_ID : Task_Id;
Time : Duration;
Mode : ST.Delay_Modes)
is
Check_Time : constant Duration := Monotonic_Clock;
Abs_Time : Duration;
Rel_Time : Duration;
Request : aliased timespec;
Result : Interfaces.C.int;
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!
SSL.Abort_Defer.all;
if Single_Lock then
Lock_RTS;
end if;
-- Comments needed in code below ???
Write_Lock (Self_ID);
if Mode = Relative then
Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
end if;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
end if;
end if;
if Abs_Time > Check_Time then
if Relative_Timed_Wait then
Request := To_Timespec (Rel_Time);
else
Request := To_Timespec (Abs_Time);
end if;
Self_ID.Common.State := Delay_Sleep;
loop
if Self_ID.Pending_Priority_Change then
Self_ID.Pending_Priority_Change := False;
Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
end if;
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
if Single_Lock then
Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
Single_RTS_Lock'Access, Request'Access);
else
Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
Self_ID.Common.LL.L'Access, Request'Access);
end if;
exit when Abs_Time <= Monotonic_Clock;
pragma Assert (Result = 0
or else Result = ETIMEDOUT
or else Result = EINTR);
end loop;
Self_ID.Common.State := Runnable;
end if;
Unlock (Self_ID);
if Single_Lock then
Unlock_RTS;
end if;
Result := sched_yield;
SSL.Abort_Undefer.all;
end Timed_Delay;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration is
TS : aliased timespec;
Result : Interfaces.C.int;
begin
Result := clock_gettime
(clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
pragma Assert (Result = 0);
return To_Duration (TS);
end Monotonic_Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration is
Res : aliased timespec;
Result : Interfaces.C.int;
begin
Result := clock_getres
(clock_id => CLOCK_REALTIME, Res => Res'Unchecked_Access);
pragma Assert (Result = 0);
return To_Duration (Res);
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_OS_Priority (T : Task_Id; Prio : System.Any_Priority) is
Result : Interfaces.C.int;
Param : aliased struct_sched_param;
begin
Param.sched_priority := Interfaces.C.int (Prio);
if Time_Slice_Supported and then Time_Slice_Val > 0 then
Result := pthread_setschedparam
(T.Common.LL.Thread, SCHED_RR, Param'Access);
elsif FIFO_Within_Priorities 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_OS_Priority;
type Prio_Array_Type is array (System.Any_Priority) of Integer;
pragma Atomic_Components (Prio_Array_Type);
Prio_Array : Prio_Array_Type;
-- Comments needed for these declarations ???
procedure Set_Priority
(T : Task_Id;
Prio : System.Any_Priority;
Loss_Of_Inheritance : Boolean := False)
is
Array_Item : Integer;
begin
Set_OS_Priority (T, Prio);
if Locking_Policy = 'C' then
-- Annex D requirements: loss of inheritance puts task at the
-- beginning of the queue for that prio; copied from 5ztaprop
-- (VxWorks)
if Loss_Of_Inheritance
and then Prio < T.Common.Current_Priority then
Array_Item := Prio_Array (T.Common.Base_Priority) + 1;
Prio_Array (T.Common.Base_Priority) := Array_Item;
loop
Yield;
exit when Array_Item = Prio_Array (T.Common.Base_Priority)
or else Prio_Array (T.Common.Base_Priority) = 1;
end loop;
Prio_Array (T.Common.Base_Priority) :=
Prio_Array (T.Common.Base_Priority) - 1;
end if;
end if;
T.Common.Current_Priority := Prio;
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
Self_ID.Common.LL.Thread := pthread_self;
Self_ID.Common.LL.LWP := lwp_self;
Specific.Set (Self_ID);
Lock_RTS;
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_RTS;
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
-- Give the task a unique serial number.
Self_ID.Serial_Number := Next_Serial_Number;
Next_Serial_Number := Next_Serial_Number + 1;
pragma Assert (Next_Serial_Number /= 0);
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;
use System.Task_Info;
begin
if Stack_Size = Unspecified_Size then
Adjusted_Stack_Size := Interfaces.C.size_t (Default_Stack_Size);
elsif Stack_Size < Minimum_Stack_Size then
Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size);
else
Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
end if;
if Stack_Base_Available then
-- If Stack Checking is supported then allocate 2 additional pages:
--
-- In the worst case, stack is allocated at something like
-- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
-- to be sure the effective stack size is greater than what
-- has been asked.
Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
end if;
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);
if T.Common.Task_Info /= Default_Scope then
-- We are assuming that Scope_Type has the same values than the
-- corresponding C macros
Result := pthread_attr_setscope
(Attributes'Access, Task_Info_Type'Pos (T.Common.Task_Info));
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);
Set_Priority (T, Priority);
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
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
Result := st_setspecific (ATCB_Key, System.Null_Address);
pragma Assert (Result = 0);
end if;
end Finalize_TCB;
---------------
-- Exit_Task --
---------------
procedure Exit_Task is
begin
Specific.Set (null);
end Exit_Task;
----------------
-- Abort_Task --
----------------
procedure Abort_Task (T : Task_Id) is
Result : Interfaces.C.int;
begin
Result := pthread_kill (T.Common.LL.Thread,
Signal (System.Interrupt_Management.Abort_Task_Interrupt));
pragma Assert (Result = 0);
end Abort_Task;
----------------
-- Check_Exit --
----------------
-- Dummy versions
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);
pragma Unreferenced (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);
pragma Unreferenced (Thread_Self);
begin
return False;
end Resume_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;
-- Initialize the lock used to synchronize chain of all ATCBs.
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
Specific.Initialize (Environment_Task);
Enter_Task (Environment_Task);
-- Install the abort-signal handler
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);
end if;
end Initialize;
begin
declare
Result : Interfaces.C.int;
begin
-- Mask Environment task for all signals. The original mask of the
-- Environment task will be recovered by Interrupt_Server task
-- during the elaboration of s-interr.adb.
System.Interrupt_Management.Operations.Set_Interrupt_Mask
(System.Interrupt_Management.Operations.All_Tasks_Mask'Access);
-- 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;
end;
end System.Task_Primitives.Operations;
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