------------------------------------------------------------------------------
-- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
+-- 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) 1992-2004, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2007, 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- --
-- 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. --
+-- 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, --
with System.Tasking.Debug;
-- used for Known_Tasks
+with System.OS_Primitives;
+-- used for Delay_Modes
+
with Interfaces.C;
-- used for int
-- size_t
-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
--- Set_Exc_Stack_Addr
-
--- 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.Stages.
+-- used for Get_Exc_Stack_Addr
+-- Abort_Defer/Undefer
-with System.OS_Primitives;
--- used for Delay_Modes
-
-with Unchecked_Conversion;
-with Unchecked_Deallocation;
+with Ada.Unchecked_Conversion;
+with Ada.Unchecked_Deallocation;
package body System.Task_Primitives.Operations is
-- 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.
+ -- A variable to hold Task_Id for the environment task
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).
+ -- Used to identified fake tasks (i.e., non-Ada Threads)
--------------------
-- Local Packages --
procedure Initialize (Environment_Task : Task_Id);
pragma Inline (Initialize);
- -- Initialize various data needed by this package.
+ -- Initialize various data needed by this package
function Is_Valid_Task return Boolean;
pragma Inline (Is_Valid_Task);
end Specific;
package body Specific is separate;
- -- The body of this package is target specific.
+ -- The body of this package is target specific
---------------------------------
-- Support for foreign threads --
-- Local Subprograms --
-----------------------
- function To_Task_Id is new Unchecked_Conversion (System.Address, Task_Id);
+ function To_Task_Id is
+ new Ada.Unchecked_Conversion (System.Address, Task_Id);
+
+ function To_Address is
+ new Ada.Unchecked_Conversion (Task_Id, System.Address);
- function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
+ function Get_Exc_Stack_Addr return Address;
+ -- Replace System.Soft_Links.Get_Exc_Stack_Addr_NT
procedure Timer_Sleep_AST (ID : Address);
- -- Signal the condition variable when AST fires.
+ -- Signal the condition variable when AST fires
procedure Timer_Sleep_AST (ID : Address) is
Result : Interfaces.C.int;
-- Stack_Guard --
-----------------
- -- The underlying thread system sets a guard page at the
- -- bottom of a thread stack, so nothing is needed.
+ -- 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
-- 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.
+ -- 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
+ procedure Initialize_Lock
+ (Prio : System.Any_Priority;
+ L : not null access Lock)
+ is
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
pragma Assert (Result = 0);
end Initialize_Lock;
- procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
+ procedure Initialize_Lock
+ (L : not null access RTS_Lock;
+ Level : Lock_Level)
+ is
pragma Unreferenced (Level);
Attributes : aliased pthread_mutexattr_t;
-- Finalize_Lock --
-------------------
- procedure Finalize_Lock (L : access Lock) is
+ procedure Finalize_Lock (L : not null access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L.L'Access);
pragma Assert (Result = 0);
end Finalize_Lock;
- procedure Finalize_Lock (L : access RTS_Lock) is
+ procedure Finalize_Lock (L : not null access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
-- Write_Lock --
----------------
- procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
+ procedure Write_Lock
+ (L : not null access Lock;
+ Ceiling_Violation : out Boolean)
+ is
Self_ID : constant Task_Id := Self;
All_Tasks_Link : constant Task_Id := Self.Common.All_Tasks_Link;
Current_Prio : System.Any_Priority;
end Write_Lock;
procedure Write_Lock
- (L : access RTS_Lock;
+ (L : not null access RTS_Lock;
Global_Lock : Boolean := False)
is
Result : Interfaces.C.int;
-- Read_Lock --
---------------
- procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
+ procedure Read_Lock
+ (L : not null access Lock;
+ Ceiling_Violation : out Boolean)
+ is
begin
Write_Lock (L, Ceiling_Violation);
end Read_Lock;
-- Unlock --
------------
- procedure Unlock (L : access Lock) is
+ procedure Unlock (L : not null access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_unlock (L.L'Access);
pragma Assert (Result = 0);
end Unlock;
- procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
+ procedure Unlock
+ (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
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 --
-----------
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
Sleep_Time := To_OS_Time (Time, Mode);
- if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
- or else Self_ID.Pending_Priority_Change
- then
+ if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level then
return;
end if;
end if;
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);
pragma Assert (Result = 0);
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);
pragma Assert (Result = 0);
end if;
Yielded : Boolean := False;
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!
-
if Single_Lock then
Lock_RTS;
end if;
-- More comments required in body below ???
- SSL.Abort_Defer.all;
Write_Lock (Self_ID);
if Time /= 0.0 or else Mode /= Relative then
(Status, 0, Sleep_Time,
Timer_Sleep_AST'Access, To_Address (Self_ID), 0);
+ -- Comment following test
+
if (Status and 1) /= 1 then
raise Storage_Error;
end if;
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;
-
if Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level then
Sys_Cantim (Status, To_Address (Self_ID), 0);
pragma Assert ((Status and 1) = 1);
end if;
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);
pragma Assert (Result = 0);
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);
pragma Assert (Result = 0);
end if;
Result := sched_yield;
pragma Assert (Result = 0);
end if;
-
- SSL.Abort_Undefer.all;
end Timed_Delay;
---------------------
function RT_Resolution return Duration is
begin
+ -- Document origin of this magic constant ???
return 10#1.0#E-3;
end RT_Resolution;
Result : Interfaces.C.int;
Param : aliased struct_sched_param;
+ function Get_Policy (Prio : System.Any_Priority) return Character;
+ pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
+ -- Get priority specific dispatching policy
+
+ Priority_Specific_Policy : constant Character := Get_Policy (Prio);
+ -- Upper case first character of the policy name corresponding to the
+ -- task as set by a Priority_Specific_Dispatching pragma.
+
begin
T.Common.Current_Priority := Prio;
Param.sched_priority := Interfaces.C.int (Underlying_Priorities (Prio));
- if Time_Slice_Val > 0 then
- Result := pthread_setschedparam
- (T.Common.LL.Thread, SCHED_RR, Param'Access);
+ if Dispatching_Policy = 'R'
+ or else Priority_Specific_Policy = 'R'
+ or else Time_Slice_Val > 0
+ then
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread, SCHED_RR, Param'Access);
- elsif FIFO_Within_Priorities or else Time_Slice_Val = 0 then
- Result := pthread_setschedparam
- (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
+ elsif Dispatching_Policy = 'F'
+ or else Priority_Specific_Policy = 'F'
+ or else Time_Slice_Val = 0
+ then
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
else
-- SCHED_OTHER priorities are restricted to the range 8 - 15.
-- in a range of 16 - 31, dividing by 2 gives the correct result.
Param.sched_priority := Param.sched_priority / 2;
- Result := pthread_setschedparam
- (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
end if;
pragma Assert (Result = 0);
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);
+ 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;
if Result = 0 then
Succeeded := True;
Self_ID.Common.LL.Exc_Stack_Ptr := new Exc_Stack_T;
- SSL.Set_Exc_Stack_Addr
- (To_Address (Self_ID),
- Self_ID.Common.LL.Exc_Stack_Ptr (Exc_Stack_T'Last)'Address);
else
if not Single_Lock then
pragma Assert (Result = 0);
end Initialize_TCB;
+ ------------------------
+ -- Get_Exc_Stack_Addr --
+ ------------------------
+
+ function Get_Exc_Stack_Addr return Address is
+ begin
+ return Self.Common.LL.Exc_Stack_Ptr (Exc_Stack_T'Last)'Address;
+ end Get_Exc_Stack_Addr;
+
-----------------
-- Create_Task --
-----------------
Priority : System.Any_Priority;
Succeeded : out Boolean)
is
- Attributes : aliased pthread_attr_t;
- Adjusted_Stack_Size : Interfaces.C.size_t;
- Result : Interfaces.C.int;
+ Attributes : aliased pthread_attr_t;
+ Result : Interfaces.C.int;
function Thread_Body_Access is new
- Unchecked_Conversion (System.Address, Thread_Body);
+ Ada.Unchecked_Conversion (System.Address, Thread_Body);
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;
-
-- Since the initial signal mask of a thread is inherited from the
-- creator, we need to set our local signal mask mask all signals
-- during the creation operation, to make sure the new thread is
pragma Assert (Result = 0);
Result := pthread_attr_setstacksize
- (Attributes'Access, Adjusted_Stack_Size);
+ (Attributes'Access, Interfaces.C.size_t (Stack_Size));
pragma Assert (Result = 0);
-- This call may be unnecessary, not sure. ???
(Attributes'Access, PTHREAD_EXPLICIT_SCHED);
pragma Assert (Result = 0);
- Result := pthread_create
- (T.Common.LL.Thread'Access,
- Attributes'Access,
- Thread_Body_Access (Wrapper),
- To_Address (T));
+ Result :=
+ pthread_create
+ (T.Common.LL.Thread'Access,
+ Attributes'Access,
+ Thread_Body_Access (Wrapper),
+ To_Address (T));
- -- ENOMEM is a valid run-time error. Don't shut down.
+ -- ENOMEM is a valid run-time error -- do not shut down
pragma Assert (Result = 0
or else Result = EAGAIN or else Result = ENOMEM);
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);
- procedure Free is new Unchecked_Deallocation
+ procedure Free is new Ada.Unchecked_Deallocation
(Exc_Stack_T, Exc_Stack_Ptr_T);
begin
end if;
Free (T.Common.LL.Exc_Stack_Ptr);
-
Free (Tmp);
if Is_Self then
procedure Exit_Task is
begin
- Specific.Set (null);
+ null;
end Exit_Task;
----------------
end Abort_Task;
----------------
+ -- Initialize --
+ ----------------
+
+ procedure Initialize (S : in out Suspension_Object) is
+ Mutex_Attr : aliased pthread_mutexattr_t;
+ Cond_Attr : aliased pthread_condattr_t;
+ Result : Interfaces.C.int;
+ begin
+ -- Initialize internal state (always to False (D.10 (6)))
+
+ S.State := False;
+ S.Waiting := False;
+
+ -- Initialize internal mutex
+
+ Result := pthread_mutexattr_init (Mutex_Attr'Access);
+ pragma Assert (Result = 0 or else Result = ENOMEM);
+
+ if Result = ENOMEM then
+ raise Storage_Error;
+ end if;
+
+ Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
+ pragma Assert (Result = 0 or else Result = ENOMEM);
+
+ if Result = ENOMEM then
+ Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
+ 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 specified in (RM D.10(9)), otherwise leave state set to True.
+
+ if S.Waiting then
+ S.Waiting := False;
+ S.State := False;
+
+ Result := pthread_cond_signal (S.CV'Access);
+ pragma Assert (Result = 0);
+
+ else
+ S.State := True;
+ end if;
+
+ Result := pthread_mutex_unlock (S.L'Access);
+ pragma Assert (Result = 0);
+
+ SSL.Abort_Undefer.all;
+ end Set_True;
+
+ ------------------------
+ -- Suspend_Until_True --
+ ------------------------
+
+ procedure Suspend_Until_True (S : in out Suspension_Object) is
+ Result : Interfaces.C.int;
+
+ begin
+ SSL.Abort_Defer.all;
+
+ Result := pthread_mutex_lock (S.L'Access);
+ pragma Assert (Result = 0);
+
+ if S.Waiting then
+
+ -- Program_Error must be raised upon calling Suspend_Until_True
+ -- if another task is already waiting on that suspension object
+ -- (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
+ -- 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 --
----------------
begin
Environment_Task_Id := Environment_Task;
+ SSL.Get_Exc_Stack_Addr := Get_Exc_Stack_Addr'Access;
+
-- Initialize the lock used to synchronize chain of all ATCBs
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
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