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------------------------------------------------------------------------------
-- --
-- GNAT 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) 1992-2006, 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, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, 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 IRIX (pthread library) 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 Interfaces.C;
-- used for int
-- size_t
with System.Task_Info;
with System.Tasking.Debug;
-- used for Known_Tasks
with System.Interrupt_Management;
-- used for Keep_Unmasked
-- Abort_Task_Interrupt
-- Interrupt_ID
with System.OS_Primitives;
-- used for Delay_Modes
with System.IO;
-- used for Put_Line
with System.Soft_Links;
-- used for Abort_Defer/Undefer
-- We use System.Soft_Links instead of System.Tasking.Initialization
-- because the later 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.Stages.
with Unchecked_Conversion;
with Unchecked_Deallocation;
package body System.Task_Primitives.Operations is
package SSL renames System.Soft_Links;
use System.Tasking;
use System.Tasking.Debug;
use Interfaces.C;
use System.OS_Interface;
use System.OS_Primitives;
use System.Parameters;
----------------
-- 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");
Real_Time_Clock_Id : constant clockid_t := CLOCK_REALTIME;
Unblocked_Signal_Mask : aliased sigset_t;
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 executing thread have a TCB?
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 --
-----------------------
function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
procedure Abort_Handler (Sig : Signal);
-- Signal handler used to implement asynchronous abort
-------------------
-- 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
then
-- 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 --
-----------------
-- The underlying thread system sets a guard page at the
-- bottom of a thread stack, so nothing is needed.
procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
pragma Unreferenced (On);
pragma Unreferenced (T);
begin
null;
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 --
---------------------
-- Note: mutexes and cond_variables needed per-task basis are
-- initialized in Initialize_TCB and the Storage_Error is
-- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
-- used in RTS is initialized before any status change of RTS.
-- Therefore rasing Storage_Error in the following routines
-- should be able to be handled safely.
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
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_setprioceiling
(Attributes'Access, Interfaces.C.int (Prio));
pragma Assert (Result = 0);
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;
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;
if Locking_Policy = 'C' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_setprioceiling
(Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
pragma Assert (Result = 0);
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);
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
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;
begin
Result := pthread_mutex_lock (L);
Ceiling_Violation := Result = EINVAL;
-- Assumes the cause of EINVAL is a priority ceiling violation
pragma Assert (Result = 0 or else Result = EINVAL);
end Write_Lock;
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;
begin
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
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 : ST.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 --
-----------------
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;
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;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
end if;
if Abs_Time > Check_Time then
Request := To_Timespec (Abs_Time);
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 else errno = EINTR then
Timedout := False;
exit;
end if;
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;
Request : aliased timespec;
Result : Interfaces.C.int;
begin
if Single_Lock then
Lock_RTS;
end if;
Write_Lock (Self_ID);
if Mode = Relative then
Abs_Time := Time + Check_Time;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
end if;
if Abs_Time > Check_Time then
Request := To_Timespec (Abs_Time);
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;
Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
Self_ID.Common.LL.L'Access, Request'Access);
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;
Yield;
end Timed_Delay;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration is
TS : aliased timespec;
Result : Interfaces.C.int;
begin
Result := clock_gettime (Real_Time_Clock_Id, TS'Unchecked_Access);
pragma Assert (Result = 0);
return To_Duration (TS);
end Monotonic_Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration is
begin
-- The clock_getres (Real_Time_Clock_Id) function appears to return
-- the interrupt resolution of the realtime clock and not the actual
-- resolution of reading the clock. Even though this last value is
-- only guaranteed to be 100 Hz, at least the Origin 200 appears to
-- have a microsecond resolution or better.
-- ??? We should figure out a method to return the right value on
-- all SGI hardware.
return 0.000_001;
end RT_Resolution;
------------
-- Wakeup --
------------
procedure Wakeup (T : ST.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;
Sched_Policy : Interfaces.C.int;
use type System.Task_Info.Task_Info_Type;
function To_Int is new Unchecked_Conversion
(System.Task_Info.Thread_Scheduling_Policy, Interfaces.C.int);
begin
T.Common.Current_Priority := Prio;
Param.sched_priority := Interfaces.C.int (Prio);
if T.Common.Task_Info /= null then
Sched_Policy := To_Int (T.Common.Task_Info.Policy);
else
Sched_Policy := SCHED_FIFO;
end if;
Result := pthread_setschedparam (T.Common.LL.Thread, Sched_Policy,
Param'Access);
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
Result : Interfaces.C.int;
function To_Int is new Unchecked_Conversion
(System.Task_Info.CPU_Number, Interfaces.C.int);
use System.Task_Info;
begin
Self_ID.Common.LL.Thread := pthread_self;
Specific.Set (Self_ID);
if Self_ID.Common.Task_Info /= null
and then Self_ID.Common.Task_Info.Scope = PTHREAD_SCOPE_SYSTEM
and then Self_ID.Common.Task_Info.Runon_CPU /= ANY_CPU
then
Result := pthread_setrunon_np
(To_Int (Self_ID.Common.Task_Info.Runon_CPU));
pragma Assert (Result = 0);
end if;
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
Result : Interfaces.C.int;
Cond_Attr : aliased pthread_condattr_t;
begin
if not Single_Lock then
Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
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
use System.Task_Info;
Attributes : aliased pthread_attr_t;
Sched_Param : aliased struct_sched_param;
Result : Interfaces.C.int;
function Thread_Body_Access is new
Unchecked_Conversion (System.Address, Thread_Body);
function To_Int is new Unchecked_Conversion
(System.Task_Info.Thread_Scheduling_Scope, Interfaces.C.int);
function To_Int is new Unchecked_Conversion
(System.Task_Info.Thread_Scheduling_Inheritance, Interfaces.C.int);
function To_Int is new Unchecked_Conversion
(System.Task_Info.Thread_Scheduling_Policy, Interfaces.C.int);
begin
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, Interfaces.C.size_t (Stack_Size));
pragma Assert (Result = 0);
if T.Common.Task_Info /= null then
Result := pthread_attr_setscope
(Attributes'Access, To_Int (T.Common.Task_Info.Scope));
pragma Assert (Result = 0);
Result := pthread_attr_setinheritsched
(Attributes'Access, To_Int (T.Common.Task_Info.Inheritance));
pragma Assert (Result = 0);
Result := pthread_attr_setschedpolicy
(Attributes'Access, To_Int (T.Common.Task_Info.Policy));
pragma Assert (Result = 0);
Sched_Param.sched_priority :=
Interfaces.C.int (T.Common.Task_Info.Priority);
Result := pthread_attr_setschedparam
(Attributes'Access, Sched_Param'Access);
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));
if Result /= 0
and then T.Common.Task_Info /= null
and then T.Common.Task_Info.Scope = PTHREAD_SCOPE_SYSTEM
then
-- The pthread_create call may have failed because we
-- asked for a system scope pthread and none were
-- available (probably because the program was not executed
-- by the superuser). Let's try for a process scope pthread
-- instead of raising Tasking_Error.
System.IO.Put_Line
("Request for PTHREAD_SCOPE_SYSTEM in Task_Info pragma for task");
System.IO.Put ("""");
System.IO.Put (T.Common.Task_Image (1 .. T.Common.Task_Image_Len));
System.IO.Put_Line (""" could not be honored. ");
System.IO.Put_Line ("Scope changed to PTHREAD_SCOPE_PROCESS");
T.Common.Task_Info.Scope := PTHREAD_SCOPE_PROCESS;
Result := pthread_attr_setscope
(Attributes'Access, To_Int (T.Common.Task_Info.Scope));
pragma Assert (Result = 0);
Result := pthread_create
(T.Common.LL.Thread'Access,
Attributes'Access,
Thread_Body_Access (Wrapper),
To_Address (T));
end if;
pragma Assert (Result = 0 or else Result = EAGAIN);
Succeeded := Result = 0;
-- The following needs significant commenting ???
if T.Common.Task_Info /= null then
T.Common.Base_Priority := T.Common.Task_Info.Priority;
Set_Priority (T, T.Common.Task_Info.Priority);
else
Set_Priority (T, Priority);
end if;
Result := pthread_attr_destroy (Attributes'Access);
pragma Assert (Result = 0);
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
Specific.Set (null);
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;
----------------
-- 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. It is always initialized to False (ARM
-- D.10 par. 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);
pragma Assert (Result = 0);
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);
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;
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
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
raise Storage_Error;
end if;
end if;
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
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 it is specified in ARM D.10 par. 9. Otherwise, it just leaves
-- the state 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
-- (ARM D.10 par. 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 (ARM D.10 par. 9).
if S.State then
S.State := False;
else
S.Waiting := True;
Result := pthread_cond_wait (S.CV'Access, S.L'Access);
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);
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;
Interrupt_Management.Initialize;
-- 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);
-- 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;
-- 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;
end System.Task_Primitives.Operations;