-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, 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- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
+-- sion. GNAT 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. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- 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. --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- This is a POSIX-like version of this package
--- This package contains all the GNULL primitives that interface directly
--- with the underlying OS.
+-- This package contains all the GNULL primitives that interface directly with
+-- the underlying OS.
--- Note: this file can only be used for POSIX compliant systems that
--- implement SCHED_FIFO and Ceiling Locking correctly.
+-- Note: this file can only be used for POSIX compliant systems that implement
+-- SCHED_FIFO and Ceiling Locking correctly.
-- For configurations where SCHED_FIFO and priority ceiling are not a
-- requirement, this file can also be used (e.g AiX threads)
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.
+-- 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 Ada.Unchecked_Conversion;
+with Ada.Unchecked_Deallocation;
-with System.Interrupt_Management;
--- used for Keep_Unmasked
--- Abort_Task_Interrupt
--- Interrupt_ID
+with Interfaces.C;
+with System.Tasking.Debug;
+with System.Interrupt_Management;
with System.OS_Primitives;
--- used for Delay_Modes
-
with System.Task_Info;
--- used for Task_Info_Type
-
-with Interfaces.C;
--- used for int
--- size_t
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.Parameters;
use System.OS_Primitives;
+ Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
+ -- Whether to use an alternate signal stack for stack overflows
+
----------------
-- Local Data --
----------------
-- Signal handler used to implement asynchronous abort.
-- See also comment before body, below.
- function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
+ function To_Address is
+ new Ada.Unchecked_Conversion (Task_Id, System.Address);
-------------------
-- Abort_Handler --
-------------------
- -- Target-dependent binding of inter-thread Abort signal to
- -- the raising of the Abort_Signal exception.
+ -- Target-dependent binding of inter-thread Abort signal to the raising of
+ -- the Abort_Signal exception.
- -- The technical issues and alternatives here are essentially
- -- the same as for raising exceptions in response to other
- -- signals (e.g. Storage_Error). See code and comments in
- -- the package body System.Interrupt_Management.
+ -- The technical issues and alternatives here are essentially the
+ -- same as for raising exceptions in response to other signals
+ -- (e.g. Storage_Error). See code and comments in the package body
+ -- System.Interrupt_Management.
- -- Some implementations may not allow an exception to be propagated
- -- out of a handler, and others might leave the signal or
- -- interrupt that invoked this handler masked after the exceptional
- -- return to the application code.
+ -- Some implementations may not allow an exception to be propagated out of
+ -- a handler, and others might leave the signal or interrupt that invoked
+ -- this handler masked after the exceptional return to the application
+ -- code.
- -- GNAT exceptions are originally implemented using setjmp()/longjmp().
- -- On most UNIX systems, this will allow transfer out of a signal handler,
+ -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
+ -- most UNIX systems, this will allow transfer out of a signal handler,
-- which is usually the only mechanism available for implementing
- -- asynchronous handlers of this kind. However, some
- -- systems do not restore the signal mask on longjmp(), leaving the
- -- abort signal masked.
+ -- asynchronous handlers of this kind. However, some systems do not
+ -- restore the signal mask on longjmp(), leaving the abort signal masked.
procedure Abort_Handler (Sig : Signal) is
- pragma Warnings (Off, Sig);
+ pragma Unreferenced (Sig);
T : constant Task_Id := Self;
- Result : Interfaces.C.int;
Old_Set : aliased sigset_t;
+ Result : Interfaces.C.int;
+ pragma Warnings (Off, Result);
+
begin
-- It is not safe to raise an exception when using ZCX and the GCC
-- exception handling mechanism.
-- Make sure signals used for RTS internal purpose are unmasked
Result := pthread_sigmask (SIG_UNBLOCK,
- Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
+ Unblocked_Signal_Mask'Access, Old_Set'Access);
pragma Assert (Result = 0);
raise Standard'Abort_Signal;
---------------------
-- Note: mutexes and cond_variables needed per-task basis are
- -- initialized in Intialize_TCB and the Storage_Error is
+ -- 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
+ -- Therefore raising Storage_Error in the following routines
-- should be able to be handled safely.
procedure Initialize_Lock
procedure Initialize_Lock
(L : not null access RTS_Lock; Level : Lock_Level)
is
- pragma Warnings (Off, Level);
+ pragma Unreferenced (Level);
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
procedure Finalize_Lock (L : not null access Lock) is
Result : Interfaces.C.int;
-
begin
Result := pthread_mutex_destroy (L);
pragma Assert (Result = 0);
procedure Finalize_Lock (L : not null access RTS_Lock) is
Result : Interfaces.C.int;
-
begin
Result := pthread_mutex_destroy (L);
pragma Assert (Result = 0);
Global_Lock : Boolean := False)
is
Result : Interfaces.C.int;
-
begin
if not Single_Lock or else Global_Lock then
Result := pthread_mutex_lock (L);
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);
procedure Unlock (L : not null access Lock) is
Result : Interfaces.C.int;
-
begin
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
(L : not null 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);
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);
end if;
end Unlock;
+ -----------------
+ -- Set_Ceiling --
+ -----------------
+
+ -- Dynamic priority ceilings are not supported by the underlying system
+
+ procedure Set_Ceiling
+ (L : not null access Lock;
+ Prio : System.Any_Priority)
+ is
+ pragma Unreferenced (L, Prio);
+ begin
+ null;
+ end Set_Ceiling;
+
-----------
-- Sleep --
-----------
(Self_ID : Task_Id;
Reason : System.Tasking.Task_States)
is
- pragma Warnings (Off, Reason);
+ 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);
+ 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);
+ Result :=
+ pthread_cond_wait
+ (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
end if;
-- EINTR is not considered a failure
Timedout : out Boolean;
Yielded : out Boolean)
is
- pragma Warnings (Off, Reason);
+ pragma Unreferenced (Reason);
- Check_Time : constant Duration := Monotonic_Clock;
+ Base_Time : constant Duration := Monotonic_Clock;
+ Check_Time : Duration := Base_Time;
Rel_Time : Duration;
Abs_Time : Duration;
Request : aliased timespec;
end if;
loop
- exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
- or else Self_ID.Pending_Priority_Change;
+ 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);
+ 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);
+ 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;
+ Check_Time := Monotonic_Clock;
+ exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
if Result = 0 or Result = EINTR then
Time : Duration;
Mode : ST.Delay_Modes)
is
- Check_Time : constant Duration := Monotonic_Clock;
+ Base_Time : constant Duration := Monotonic_Clock;
+ Check_Time : Duration := Base_Time;
Abs_Time : Duration;
Rel_Time : Duration;
Request : aliased timespec;
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
Request'Access);
end if;
- exit when Abs_Time <= Monotonic_Clock;
+ Check_Time := Monotonic_Clock;
+ exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
pragma Assert (Result = 0
or else Result = ETIMEDOUT
------------
procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
- pragma Warnings (Off, Reason);
+ pragma Unreferenced (Reason);
Result : Interfaces.C.int;
begin
Result := pthread_cond_signal (T.Common.LL.CV'Access);
Prio : System.Any_Priority;
Loss_Of_Inheritance : Boolean := False)
is
- pragma Warnings (Off, Loss_Of_Inheritance);
+ pragma Unreferenced (Loss_Of_Inheritance);
Result : Interfaces.C.int;
Param : aliased struct_sched_param;
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;
+ if Use_Alternate_Stack then
+ declare
+ Stack : aliased stack_t;
+ Result : Interfaces.C.int;
+ begin
+ Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
+ Stack.ss_size := Alternate_Stack_Size;
+ Stack.ss_flags := 0;
+ Result := sigaltstack (Stack'Access, null);
+ pragma Assert (Result = 0);
+ end;
+ end if;
end Enter_Task;
--------------
if Result = 0 then
if Locking_Policy = 'C' then
- Result := pthread_mutexattr_setprotocol
- (Mutex_Attr'Access, PTHREAD_PRIO_PROTECT);
+ Result :=
+ pthread_mutexattr_setprotocol
+ (Mutex_Attr'Access,
+ PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
- Result := pthread_mutexattr_setprioceiling
- (Mutex_Attr'Access,
- Interfaces.C.int (System.Any_Priority'Last));
+ Result :=
+ pthread_mutexattr_setprioceiling
+ (Mutex_Attr'Access,
+ Interfaces.C.int (System.Any_Priority'Last));
pragma Assert (Result = 0);
elsif Locking_Policy = 'I' then
- Result := pthread_mutexattr_setprotocol
- (Mutex_Attr'Access, PTHREAD_PRIO_INHERIT);
+ Result :=
+ pthread_mutexattr_setprotocol
+ (Mutex_Attr'Access,
+ PTHREAD_PRIO_INHERIT);
pragma Assert (Result = 0);
end if;
- Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
- Mutex_Attr'Access);
+ Result :=
+ pthread_mutex_init
+ (Self_ID.Common.LL.L'Access,
+ Mutex_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
end if;
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);
+ Result :=
+ pthread_cond_init
+ (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
end if;
Result : Interfaces.C.int;
function Thread_Body_Access is new
- Unchecked_Conversion (System.Address, Thread_Body);
+ Ada.Unchecked_Conversion (System.Address, Thread_Body);
use System.Task_Info;
begin
- Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
+ Adjusted_Stack_Size :=
+ Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
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
return;
end if;
- Result := pthread_attr_setdetachstate
- (Attributes'Access, PTHREAD_CREATE_DETACHED);
+ Result :=
+ pthread_attr_setdetachstate
+ (Attributes'Access, PTHREAD_CREATE_DETACHED);
pragma Assert (Result = 0);
- Result := pthread_attr_setstacksize
- (Attributes'Access, Adjusted_Stack_Size);
+ Result :=
+ pthread_attr_setstacksize
+ (Attributes'Access, Adjusted_Stack_Size);
pragma Assert (Result = 0);
if T.Common.Task_Info /= Default_Scope then
case T.Common.Task_Info is
when System.Task_Info.Process_Scope =>
- Result := pthread_attr_setscope
- (Attributes'Access, PTHREAD_SCOPE_PROCESS);
+ Result :=
+ pthread_attr_setscope
+ (Attributes'Access, PTHREAD_SCOPE_PROCESS);
when System.Task_Info.System_Scope =>
- Result := pthread_attr_setscope
- (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
+ Result :=
+ pthread_attr_setscope
+ (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
when System.Task_Info.Default_Scope =>
Result := 0;
Result := pthread_attr_destroy (Attributes'Access);
pragma Assert (Result = 0);
- Set_Priority (T, Priority);
+ if Succeeded then
+ Set_Priority (T, Priority);
+ end if;
end Create_Task;
------------------
Is_Self : constant Boolean := T = Self;
procedure Free is new
- Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
+ Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
begin
if not Single_Lock then
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));
+ Result :=
+ pthread_kill
+ (T.Common.LL.Thread,
+ Signal (System.Interrupt_Management.Abort_Task_Interrupt));
pragma Assert (Result = 0);
end Abort_Task;
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).
+ -- Initialize internal state (always to False (RM D.10 (6)))
S.State := False;
S.Waiting := False;
if Result = ENOMEM then
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
-
raise Storage_Error;
end if;
end if;
--------------
procedure Finalize (S : in out Suspension_Object) is
- Result : Interfaces.C.int;
+ Result : Interfaces.C.int;
+
begin
-- Destroy internal mutex
---------------
procedure Set_False (S : in out Suspension_Object) is
- Result : Interfaces.C.int;
+ Result : Interfaces.C.int;
+
begin
SSL.Abort_Defer.all;
procedure Set_True (S : in out Suspension_Object) is
Result : Interfaces.C.int;
+
begin
SSL.Abort_Defer.all;
-- 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
+ -- as it is specified in (RM D.10(9)). Otherwise, it just leaves
-- the state to True.
if S.Waiting then
Result := pthread_cond_signal (S.CV'Access);
pragma Assert (Result = 0);
+
else
S.State := True;
end if;
procedure Suspend_Until_True (S : in out Suspension_Object) is
Result : Interfaces.C.int;
+
begin
SSL.Abort_Defer.all;
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).
+ -- (RM 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
S.State := False;
else
S.Waiting := True;
- Result := pthread_cond_wait (S.CV'Access, S.L'Access);
+
+ 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);
-- Dummy version
function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
- pragma Warnings (Off, Self_ID);
+ pragma Unreferenced (Self_ID);
begin
return True;
end Check_Exit;
--------------------
function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
- pragma Warnings (Off, Self_ID);
+ pragma Unreferenced (Self_ID);
begin
return True;
end Check_No_Locks;
(T : ST.Task_Id;
Thread_Self : Thread_Id) return Boolean
is
- pragma Warnings (Off, T);
- pragma Warnings (Off, Thread_Self);
+ pragma Unreferenced (T, Thread_Self);
begin
return False;
end Suspend_Task;
(T : ST.Task_Id;
Thread_Self : Thread_Id) return Boolean
is
- pragma Warnings (Off, T);
- pragma Warnings (Off, Thread_Self);
+ 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 --
----------------
Specific.Initialize (Environment_Task);
+ if Use_Alternate_Stack then
+ Environment_Task.Common.Task_Alternate_Stack :=
+ Alternate_Stack'Address;
+ end if;
+
+ -- 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);
-- Install the abort-signal handler
- if State (System.Interrupt_Management.Abort_Task_Interrupt)
- /= Default
+ if State
+ (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
then
act.sa_flags := 0;
act.sa_handler := Abort_Handler'Address;
Result :=
sigaction
- (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
- act'Unchecked_Access,
- old_act'Unchecked_Access);
+ (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
+ act'Unchecked_Access,
+ old_act'Unchecked_Access);
pragma Assert (Result = 0);
end if;
end Initialize;
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