-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2007, 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. --
------------------------------------------------------------------------------
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 Ada.Exceptions;
--- Used for Raise_Exception
+with Ada.Unchecked_Deallocation;
+with System.Interrupt_Management;
with System.Tasking.Debug;
--- Used for enabling tasking facilities with gdb
-
with System.Address_Image;
--- Used for the function itself
-
+with System.Task_Primitives;
with System.Task_Primitives.Operations;
--- Used for Finalize_Lock
--- Enter_Task
--- Write_Lock
--- Unlock
--- Sleep
--- Wakeup
--- Get_Priority
--- Lock/Unlock_RTS
--- New_ATCB
-
-with System.Soft_Links;
--- These are procedure pointers to non-tasking routines that use task
--- specific data. In the absence of tasking, these routines refer to global
--- data. In the presense of tasking, they must be replaced with pointers to
--- task-specific versions. Also used for Create_TSD, Destroy_TSD,
--- Get_Current_Excep, Finalize_Global_List, Task_Termination, Handler.
-
-with System.Tasking.Initialization;
--- Used for Remove_From_All_Tasks_List
--- Defer_Abort
--- Undefer_Abort
--- Finalize_Attributes_Link
--- Initialize_Attributes_Link
-
-pragma Elaborate_All (System.Tasking.Initialization);
--- This insures that tasking is initialized if any tasks are created
-
with System.Tasking.Utilities;
--- Used for Make_Passive
--- Abort_One_Task
--- Abort_Tasks
-
with System.Tasking.Queuing;
--- Used for Dequeue_Head
-
with System.Tasking.Rendezvous;
--- Used for Call_Simple
-
with System.OS_Primitives;
--- Used for Delay_Modes
-
with System.Secondary_Stack;
--- Used for SS_Init
-
with System.Storage_Elements;
--- Used for Storage_Array
-
with System.Restrictions;
--- Used for Abort_Allowed
-
with System.Standard_Library;
--- Used for Exception_Trace
-
with System.Traces.Tasking;
--- Used for Send_Trace_Info
+with System.Stack_Usage;
-with Ada.Unchecked_Deallocation;
--- To recover from failure of ATCB initialization
+with System.Soft_Links;
+-- These are procedure pointers to non-tasking routines that use task
+-- specific data. In the absence of tasking, these routines refer to global
+-- data. In the presence of tasking, they must be replaced with pointers to
+-- task-specific versions. Also used for Create_TSD, Destroy_TSD,
+-- Get_Current_Excep, Finalize_Global_List, Task_Termination, Handler.
-with System.Stack_Usage;
+with System.Tasking.Initialization;
+pragma Elaborate_All (System.Tasking.Initialization);
+-- This insures that tasking is initialized if any tasks are created
package body System.Tasking.Stages is
procedure Free is new
Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
+ procedure Free_Entry_Names (T : Task_Id);
+ -- Deallocate all string names associated with task entries
+
procedure Trace_Unhandled_Exception_In_Task (Self_Id : Task_Id);
-- This procedure outputs the task specific message for exception
-- tracing purposes.
procedure Vulnerable_Complete_Task (Self_ID : Task_Id);
-- Complete the calling task. This procedure must be called with
-- abort deferred. It should only be called by Complete_Task and
- -- Finalizate_Global_Tasks (for the environment task).
+ -- Finalize_Global_Tasks (for the environment task).
procedure Vulnerable_Complete_Master (Self_ID : Task_Id);
-- Complete the current master of the calling task. This procedure
-- This procedure must be called with abort deferred.
procedure Abort_Dependents (Self_ID : Task_Id);
- -- Abort all the direct dependents of Self at its current master
- -- nesting level, plus all of their dependents, transitively.
- -- RTS_Lock should be locked by the caller.
+ -- Abort all the direct dependents of Self at its current master nesting
+ -- level, plus all of their dependents, transitively. RTS_Lock should be
+ -- locked by the caller.
procedure Vulnerable_Free_Task (T : Task_Id);
- -- Recover all runtime system storage associated with the task T.
- -- This should only be called after T has terminated and will no
- -- longer be referenced.
- --
- -- For tasks created by an allocator that fails, due to an exception,
- -- it is called from Expunge_Unactivated_Tasks.
+ -- Recover all runtime system storage associated with the task T. This
+ -- should only be called after T has terminated and will no longer be
+ -- referenced.
--
- -- It is also called from Ada.Unchecked_Deallocation, for objects that
- -- are or contain tasks.
+ -- For tasks created by an allocator that fails, due to an exception, it is
+ -- called from Expunge_Unactivated_Tasks.
--
-- Different code is used at master completion, in Terminate_Dependents,
-- due to a need for tighter synchronization with the master.
-- Activate_Tasks --
--------------------
- -- Note that locks of activator and activated task are both locked
- -- here. This is necessary because C.Common.State and
- -- Self.Common.Wait_Count have to be synchronized. This is safe from
- -- deadlock because the activator is always created before the activated
- -- task. That satisfies our in-order-of-creation ATCB locking policy.
-
- -- At one point, we may also lock the parent, if the parent is
- -- different from the activator. That is also consistent with the
- -- lock ordering policy, since the activator cannot be created
- -- before the parent.
-
- -- Since we are holding both the activator's lock, and Task_Wrapper
- -- locks that before it does anything more than initialize the
- -- low-level ATCB components, it should be safe to wait to update
- -- the counts until we see that the thread creation is successful.
-
- -- If the thread creation fails, we do need to close the entries
- -- of the task. The first phase, of dequeuing calls, only requires
- -- locking the acceptor's ATCB, but the waking up of the callers
- -- requires locking the caller's ATCB. We cannot safely do this
- -- while we are holding other locks. Therefore, the queue-clearing
- -- operation is done in a separate pass over the activation chain.
+ -- Note that locks of activator and activated task are both locked here.
+ -- This is necessary because C.Common.State and Self.Common.Wait_Count have
+ -- to be synchronized. This is safe from deadlock because the activator is
+ -- always created before the activated task. That satisfies our
+ -- in-order-of-creation ATCB locking policy.
+
+ -- At one point, we may also lock the parent, if the parent is different
+ -- from the activator. That is also consistent with the lock ordering
+ -- policy, since the activator cannot be created before the parent.
+
+ -- Since we are holding both the activator's lock, and Task_Wrapper locks
+ -- that before it does anything more than initialize the low-level ATCB
+ -- components, it should be safe to wait to update the counts until we see
+ -- that the thread creation is successful.
+
+ -- If the thread creation fails, we do need to close the entries of the
+ -- task. The first phase, of dequeuing calls, only requires locking the
+ -- acceptor's ATCB, but the waking up of the callers requires locking the
+ -- caller's ATCB. We cannot safely do this while we are holding other
+ -- locks. Therefore, the queue-clearing operation is done in a separate
+ -- pass over the activation chain.
procedure Activate_Tasks (Chain_Access : Activation_Chain_Access) is
Self_ID : constant Task_Id := STPO.Self;
if System.Tasking.Detect_Blocking
and then Self_ID.Common.Protected_Action_Nesting > 0
then
- Ada.Exceptions.Raise_Exception
- (Program_Error'Identity, "potentially blocking operation");
+ raise Program_Error with "potentially blocking operation";
end if;
pragma Debug
All_Elaborated := False;
end if;
- -- Reverse the activation chain so that tasks are
- -- activated in the same order they're declared.
+ -- Reverse the activation chain so that tasks are activated in the
+ -- same order they're declared.
Next_C := C.Common.Activation_Link;
C.Common.Activation_Link := Last_C;
if not All_Elaborated then
Unlock_RTS;
Initialization.Undefer_Abort_Nestable (Self_ID);
- Raise_Exception
- (Program_Error'Identity, "Some tasks have not been elaborated");
+ raise Program_Error with "Some tasks have not been elaborated";
end if;
-- Activate all the tasks in the chain. Creation of the thread of
Write_Lock (P);
Write_Lock (C);
- if C.Common.Base_Priority < Get_Priority (Self_ID) then
- Activate_Prio := Get_Priority (Self_ID);
- else
- Activate_Prio := C.Common.Base_Priority;
- end if;
+ Activate_Prio :=
+ (if C.Common.Base_Priority < Get_Priority (Self_ID)
+ then Get_Priority (Self_ID)
+ else C.Common.Base_Priority);
System.Task_Primitives.Operations.Create_Task
(C, Task_Wrapper'Address,
(C.Common.Compiler_Data.Pri_Stack_Info.Size),
Activate_Prio, Success);
- -- There would be a race between the created task and the
- -- creator to do the following initialization, if we did not
- -- have a Lock/Unlock_RTS pair in the task wrapper to prevent
- -- it from racing ahead.
+ -- There would be a race between the created task and the creator
+ -- to do the following initialization, if we did not have a
+ -- Lock/Unlock_RTS pair in the task wrapper to prevent it from
+ -- racing ahead.
if Success then
- C.Common.State := Runnable;
+ C.Common.State := Activating;
C.Awake_Count := 1;
C.Alive_Count := 1;
P.Awake_Count := P.Awake_Count + 1;
P.Common.Wait_Count := P.Common.Wait_Count + 1;
end if;
+ for J in System.Tasking.Debug.Known_Tasks'Range loop
+ if System.Tasking.Debug.Known_Tasks (J) = null then
+ System.Tasking.Debug.Known_Tasks (J) := C;
+ C.Known_Tasks_Index := J;
+ exit;
+ end if;
+ end loop;
+
+ if Global_Task_Debug_Event_Set then
+ Debug.Signal_Debug_Event
+ (Debug.Debug_Event_Activating, C);
+ end if;
+
+ C.Common.State := Runnable;
+
Unlock (C);
Unlock (P);
Unlock_RTS;
end if;
- -- Close the entries of any tasks that failed thread creation,
- -- and count those that have not finished activation.
+ -- Close the entries of any tasks that failed thread creation, and count
+ -- those that have not finished activation.
Write_Lock (Self_ID);
Self_ID.Common.State := Activator_Sleep;
if Self_ID.Common.Activation_Failed then
Self_ID.Common.Activation_Failed := False;
- Raise_Exception (Tasking_Error'Identity,
- "Failure during activation");
+ raise Tasking_Error with "Failure during activation";
end if;
end Activate_Tasks;
Initialization.Undefer_Abort_Nestable (Self_ID);
- -- ???
- -- Why do we need to allow for nested deferral here?
+ -- ??? Why do we need to allow for nested deferral here?
if Runtime_Traces then
Send_Trace_Info (T_Activate);
-- Create_Task --
-----------------
- -- Compiler interface only. Do not call from within the RTS.
- -- This must be called to create a new task.
+ -- Compiler interface only. Do not call from within the RTS. This must be
+ -- called to create a new task.
procedure Create_Task
- (Priority : Integer;
- Size : System.Parameters.Size_Type;
- Task_Info : System.Task_Info.Task_Info_Type;
- Num_Entries : Task_Entry_Index;
- Master : Master_Level;
- State : Task_Procedure_Access;
- Discriminants : System.Address;
- Elaborated : Access_Boolean;
- Chain : in out Activation_Chain;
- Task_Image : String;
- Created_Task : out Task_Id)
+ (Priority : Integer;
+ Size : System.Parameters.Size_Type;
+ Task_Info : System.Task_Info.Task_Info_Type;
+ Relative_Deadline : Ada.Real_Time.Time_Span;
+ Num_Entries : Task_Entry_Index;
+ Master : Master_Level;
+ State : Task_Procedure_Access;
+ Discriminants : System.Address;
+ Elaborated : Access_Boolean;
+ Chain : in out Activation_Chain;
+ Task_Image : String;
+ Created_Task : out Task_Id;
+ Build_Entry_Names : Boolean)
is
T, P : Task_Id;
Self_ID : constant Task_Id := STPO.Self;
Base_Priority : System.Any_Priority;
Len : Natural;
+ pragma Unreferenced (Relative_Deadline);
+ -- EDF scheduling is not supported by any of the target platforms so
+ -- this parameter is not passed any further.
+
begin
-- If Master is greater than the current master, it means that Master
-- has already awaited its dependent tasks. This raises Program_Error,
"create task after awaiting termination";
end if;
- -- If pragma Detect_Blocking is active must be checked whether
- -- this potentially blocking operation is called from a
- -- protected action.
+ -- If pragma Detect_Blocking is active must be checked whether this
+ -- potentially blocking operation is called from a protected action.
if System.Tasking.Detect_Blocking
and then Self_ID.Common.Protected_Action_Nesting > 0
then
- Ada.Exceptions.Raise_Exception
- (Program_Error'Identity, "potentially blocking operation");
+ raise Program_Error with "potentially blocking operation";
end if;
- pragma Debug
- (Debug.Trace (Self_ID, "Create_Task", 'C'));
+ pragma Debug (Debug.Trace (Self_ID, "Create_Task", 'C'));
- if Priority = Unspecified_Priority then
- Base_Priority := Self_ID.Common.Base_Priority;
- else
- Base_Priority := System.Any_Priority (Priority);
- end if;
+ Base_Priority :=
+ (if Priority = Unspecified_Priority
+ then Self_ID.Common.Base_Priority
+ else System.Any_Priority (Priority));
-- Find parent P of new Task, via master level number
exception
when others =>
Initialization.Undefer_Abort_Nestable (Self_ID);
- Raise_Exception (Storage_Error'Identity, "Cannot allocate task");
+ raise Storage_Error with "Cannot allocate task";
end;
- -- RTS_Lock is used by Abort_Dependents and Abort_Tasks.
- -- Up to this point, it is possible that we may be part of
- -- a family of tasks that is being aborted.
+ -- RTS_Lock is used by Abort_Dependents and Abort_Tasks. Up to this
+ -- point, it is possible that we may be part of a family of tasks that
+ -- is being aborted.
Lock_RTS;
Write_Lock (Self_ID);
- -- Now, we must check that we have not been aborted.
- -- If so, we should give up on creating this task,
- -- and simply return.
+ -- Now, we must check that we have not been aborted. If so, we should
+ -- give up on creating this task, and simply return.
if not Self_ID.Callable then
pragma Assert (Self_ID.Pending_ATC_Level = 0);
Unlock (Self_ID);
Unlock_RTS;
Initialization.Undefer_Abort_Nestable (Self_ID);
- Raise_Exception
- (Storage_Error'Identity, "Failed to initialize task");
+ raise Storage_Error with "Failed to initialize task";
+ end if;
+
+ if Master = Foreign_Task_Level + 2 then
+
+ -- This should not happen, except when a foreign task creates non
+ -- library-level Ada tasks. In this case, we pretend the master is
+ -- a regular library level task, otherwise the run-time will get
+ -- confused when waiting for these tasks to terminate.
+
+ T.Master_of_Task := Library_Task_Level;
+
+ else
+ T.Master_of_Task := Master;
end if;
- T.Master_of_Task := Master;
T.Master_Within := T.Master_of_Task + 1;
for L in T.Entry_Calls'Range loop
Unlock (Self_ID);
Unlock_RTS;
+ -- Note: we should not call 'new' while holding locks since new
+ -- may use locks (e.g. RTS_Lock under Windows) itself and cause a
+ -- deadlock.
+
+ if Build_Entry_Names then
+ T.Entry_Names :=
+ new Entry_Names_Array (1 .. Entry_Index (Num_Entries));
+ end if;
+
-- Create TSD as early as possible in the creation of a task, since it
-- may be used by the operation of Ada code within the task.
Initialization.Defer_Abort_Nestable (Self_ID);
-- ???
- -- Experimentation has shown that abort is sometimes (but not
- -- always) already deferred when this is called.
+ -- Experimentation has shown that abort is sometimes (but not always)
+ -- already deferred when this is called.
-- That may indicate an error. Find out what is going on
---------------------------
-- ???
- -- We have a potential problem here if finalization of global
- -- objects does anything with signals or the timer server, since
- -- by that time those servers have terminated.
+ -- We have a potential problem here if finalization of global objects does
+ -- anything with signals or the timer server, since by that time those
+ -- servers have terminated.
-- It is hard to see how that would occur
procedure Finalize_Global_Tasks is
Self_ID : constant Task_Id := STPO.Self;
+
Ignore : Boolean;
+ pragma Unreferenced (Ignore);
+
+ function State
+ (Int : System.Interrupt_Management.Interrupt_ID) return Character;
+ pragma Import (C, State, "__gnat_get_interrupt_state");
+ -- Get interrupt state for interrupt number Int. Defined in init.c
+
+ Default : constant Character := 's';
+ -- 's' Interrupt_State pragma set state to System (use "default"
+ -- system handler)
begin
if Self_ID.Deferral_Level = 0 then
-- ???
- -- In principle, we should be able to predict whether
- -- abort is already deferred here (and it should not be deferred
- -- yet but in practice it seems Finalize_Global_Tasks is being
- -- called sometimes, from RTS code for exceptions, with abort already
- -- deferred.
+ -- In principle, we should be able to predict whether abort is
+ -- already deferred here (and it should not be deferred yet but in
+ -- practice it seems Finalize_Global_Tasks is being called sometimes,
+ -- from RTS code for exceptions, with abort already deferred.
Initialization.Defer_Abort_Nestable (Self_ID);
Unlock_RTS;
end if;
- -- We need to explicitely wait for the task to be terminated here
- -- because on true concurrent system, we may end this procedure
- -- before the tasks are really terminated.
+ -- We need to explicitly wait for the task to be terminated here
+ -- because on true concurrent system, we may end this procedure before
+ -- the tasks are really terminated.
Write_Lock (Self_ID);
- loop
- exit when Utilities.Independent_Task_Count = 0;
+ -- If the Abort_Task signal is set to system, it means that we may not
+ -- have been able to abort all independent tasks (in particular
+ -- Server_Task may be blocked, waiting for a signal), in which case,
+ -- do not wait for Independent_Task_Count to go down to 0.
- -- We used to yield here, but this did not take into account
- -- low priority tasks that would cause dead lock in some cases
- -- (true FIFO scheduling).
+ if State
+ (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
+ then
+ loop
+ exit when Utilities.Independent_Task_Count = 0;
- Timed_Sleep
- (Self_ID, 0.01, System.OS_Primitives.Relative,
- Self_ID.Common.State, Ignore, Ignore);
- end loop;
+ -- We used to yield here, but this did not take into account low
+ -- priority tasks that would cause dead lock in some cases (true
+ -- FIFO scheduling).
+
+ Timed_Sleep
+ (Self_ID, 0.01, System.OS_Primitives.Relative,
+ Self_ID.Common.State, Ignore, Ignore);
+ end loop;
+ end if;
-- ??? On multi-processor environments, it seems that the above loop
-- isn't sufficient, so we need to add an additional delay.
end Finalize_Global_Tasks;
+ ----------------------
+ -- Free_Entry_Names --
+ ----------------------
+
+ procedure Free_Entry_Names (T : Task_Id) is
+ Names : Entry_Names_Array_Access := T.Entry_Names;
+
+ procedure Free_Entry_Names_Array_Access is new
+ Ada.Unchecked_Deallocation
+ (Entry_Names_Array, Entry_Names_Array_Access);
+
+ begin
+ if Names = null then
+ return;
+ end if;
+
+ Free_Entry_Names_Array (Names.all);
+ Free_Entry_Names_Array_Access (Names);
+ end Free_Entry_Names;
+
---------------
-- Free_Task --
---------------
Initialization.Task_Lock (Self_Id);
Lock_RTS;
+ Initialization.Finalize_Attributes_Link.all (T);
Initialization.Remove_From_All_Tasks_List (T);
Unlock_RTS;
Initialization.Task_Unlock (Self_Id);
+ Free_Entry_Names (T);
System.Task_Primitives.Operations.Finalize_TCB (T);
-- If the task is not terminated, then we simply ignore the call. This
Initialization.Undefer_Abort (Self_ID);
end Move_Activation_Chain;
+ -- Compiler interface only. Do not call from within the RTS
+
+ --------------------
+ -- Set_Entry_Name --
+ --------------------
+
+ procedure Set_Entry_Name
+ (T : Task_Id;
+ Pos : Task_Entry_Index;
+ Val : String_Access)
+ is
+ begin
+ pragma Assert (T.Entry_Names /= null);
+
+ T.Entry_Names (Entry_Index (Pos)) := Val;
+ end Set_Entry_Name;
+
------------------
-- Task_Wrapper --
------------------
- -- The task wrapper is a procedure that is called first for each task
- -- task body, and which in turn calls the compiler-generated task body
- -- procedure. The wrapper's main job is to do initialization for the task.
- -- It also has some locally declared objects that server as per-task local
- -- data. Task finalization is done by Complete_Task, which is called from
- -- an at-end handler that the compiler generates.
+ -- The task wrapper is a procedure that is called first for each task body
+ -- and which in turn calls the compiler-generated task body procedure.
+ -- The wrapper's main job is to do initialization for the task. It also
+ -- has some locally declared objects that serve as per-task local data.
+ -- Task finalization is done by Complete_Task, which is called from an
+ -- at-end handler that the compiler generates.
procedure Task_Wrapper (Self_ID : Task_Id) is
use type SSE.Storage_Offset;
Bottom_Of_Stack : aliased Integer;
+ Task_Alternate_Stack :
+ aliased SSE.Storage_Array (1 .. Alternate_Stack_Size);
+ -- The alternate signal stack for this task, if any
+
+ Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
+ -- Whether to use above alternate signal stack for stack overflows
+
Secondary_Stack_Size :
constant SSE.Storage_Offset :=
Self_ID.Common.Compiler_Data.Pri_Stack_Info.Size *
-- Why are warnings being turned off here???
Secondary_Stack_Address : System.Address := Secondary_Stack'Address;
+ -- Address of secondary stack. In the fixed secondary stack case, this
+ -- value is not modified, causing a warning, hence the bracketing with
+ -- Warnings (Off/On). But why is so much *more* bracketed???
Small_Overflow_Guard : constant := 12 * 1024;
-- Note: this used to be 4K, but was changed to 12K, since smaller
-- Size of the overflow guard, used by dynamic stack usage analysis
pragma Warnings (On);
- -- Address of secondary stack. In the fixed secondary stack case, this
- -- value is not modified, causing a warning, hence the bracketing with
- -- Warnings (Off/On). But why is so much *more* bracketed ???
SEH_Table : aliased SSE.Storage_Array (1 .. 8);
-- Structured Exception Registration table (2 words)
-- Assume a size of the stack taken at this stage
- if Size < Small_Stack_Limit then
- Overflow_Guard := Small_Overflow_Guard;
- else
- Overflow_Guard := Big_Overflow_Guard;
- end if;
-
- Size := Size - Overflow_Guard;
+ Overflow_Guard :=
+ (if Size < Small_Stack_Limit
+ then Small_Overflow_Guard
+ else Big_Overflow_Guard);
if not Parameters.Sec_Stack_Dynamic then
Self_ID.Common.Compiler_Data.Sec_Stack_Addr :=
Size := Size - Natural (Secondary_Stack_Size);
end if;
+ if Use_Alternate_Stack then
+ Self_ID.Common.Task_Alternate_Stack := Task_Alternate_Stack'Address;
+ end if;
+
+ Size := Size - Overflow_Guard;
+
if System.Stack_Usage.Is_Enabled then
STPO.Lock_RTS;
- Initialize_Analyzer (Self_ID.Common.Analyzer,
- Self_ID.Common.Task_Image
- (1 .. Self_ID.Common.Task_Image_Len),
- Size,
- Overflow_Guard,
- SSE.To_Integer (Bottom_Of_Stack'Address));
+ Initialize_Analyzer
+ (Self_ID.Common.Analyzer,
+ Self_ID.Common.Task_Image
+ (1 .. Self_ID.Common.Task_Image_Len),
+ Natural
+ (Self_ID.Common.Compiler_Data.Pri_Stack_Info.Size),
+ Size,
+ SSE.To_Integer (Bottom_Of_Stack'Address));
STPO.Unlock_RTS;
Fill_Stack (Self_ID.Common.Analyzer);
end if;
Stack_Guard (Self_ID, True);
- -- Initialize low-level TCB components, that cannot be initialized
- -- by the creator. Enter_Task sets Self_ID.Known_Tasks_Index and
- -- also Self_ID.LL.Thread
+ -- Initialize low-level TCB components, that cannot be initialized by
+ -- the creator. Enter_Task sets Self_ID.LL.Thread
Enter_Task (Self_ID);
Self_ID.Deferral_Level := 0;
end if;
+ if Global_Task_Debug_Event_Set then
+ Debug.Signal_Debug_Event
+ (Debug.Debug_Event_Run, Self_ID);
+ end if;
+
begin
-- We are separating the following portion of the code in order to
-- place the exception handlers in a different block. In this way,
if Self_ID.Terminate_Alternative then
Cause := Normal;
+
+ if Global_Task_Debug_Event_Set then
+ Debug.Signal_Debug_Event
+ (Debug.Debug_Event_Terminated, Self_ID);
+ end if;
else
Cause := Abnormal;
+
+ if Global_Task_Debug_Event_Set then
+ Debug.Signal_Debug_Event
+ (Debug.Debug_Event_Abort_Terminated, Self_ID);
+ end if;
end if;
when others =>
- -- ??? Using an E : others here causes CD2C11A to fail on Tru64.
+ -- ??? Using an E : others here causes CD2C11A to fail on Tru64
Initialization.Defer_Abort_Nestable (Self_ID);
-- procedure, as well as the associated Exception_Occurrence.
Cause := Unhandled_Exception;
+
Save_Occurrence (EO, SSL.Get_Current_Excep.all.all);
+
+ if Global_Task_Debug_Event_Set then
+ Debug.Signal_Debug_Event
+ (Debug.Debug_Event_Exception_Terminated, Self_ID);
+ end if;
end;
-- Look for a task termination handler. This code is for all tasks but
--------------------
-- Before we allow the thread to exit, we must clean up. This is a
- -- a delicate job. We must wake up the task's master, who may immediately
- -- try to deallocate the ATCB out from under the current task WHILE IT IS
- -- STILL EXECUTING.
+ -- delicate job. We must wake up the task's master, who may immediately try
+ -- to deallocate the ATCB out from under the current task WHILE IT IS STILL
+ -- EXECUTING.
-- To avoid this, the parent task must be blocked up to the latest
-- statement executed. The trouble is that we have another step that we
-- Check if the current task is an independent task If so, decrement
-- the Independent_Task_Count value.
- if Master_of_Task = 2 then
+ if Master_of_Task = Independent_Task_Level then
if Single_Lock then
Utilities.Independent_Task_Count :=
Utilities.Independent_Task_Count - 1;
SSL.Destroy_TSD (Self_ID.Common.Compiler_Data);
Initialization.Final_Task_Unlock (Self_ID);
- -- WARNING: past this point, this thread must assume that the ATCB
- -- has been deallocated. It should not be accessed again.
+ -- WARNING: past this point, this thread must assume that the ATCB has
+ -- been deallocated. It should not be accessed again.
if Master_of_Task > 0 then
STPO.Exit_Task;
use System.Standard_Library;
function To_Address is new
- Ada.Unchecked_Conversion (Task_Id, System.Address);
+ Ada.Unchecked_Conversion
+ (Task_Id, System.Task_Primitives.Task_Address);
function Tailored_Exception_Information
(E : Exception_Occurrence) return String;
-- unwound. The common notification routine has been called at the
-- raise point already.
+ -- Lock to prevent unsynchronized output
+
+ Initialization.Task_Lock (Self_Id);
To_Stderr ("task ");
if Self_Id.Common.Task_Image_Len /= 0 then
To_Stderr (" terminated by unhandled exception");
To_Stderr ((1 => ASCII.LF));
To_Stderr (Tailored_Exception_Information (Excep.all));
+ Initialization.Task_Unlock (Self_Id);
end Trace_Unhandled_Exception_In_Task;
------------------------------------
Unlock (Self_ID);
Unlock (Activator);
- -- After the activation, active priority should be the same
- -- as base priority. We must unlock the Activator first,
- -- though, since it should not wait if we have lower priority.
+ -- After the activation, active priority should be the same as base
+ -- priority. We must unlock the Activator first, though, since it
+ -- should not wait if we have lower priority.
if Get_Priority (Self_ID) /= Self_ID.Common.Base_Priority then
Write_Lock (Self_ID);
--------------------------------
procedure Vulnerable_Complete_Master (Self_ID : Task_Id) is
- C : Task_Id;
- P : Task_Id;
- CM : constant Master_Level := Self_ID.Master_Within;
- T : aliased Task_Id;
+ C : Task_Id;
+ P : Task_Id;
+ CM : constant Master_Level := Self_ID.Master_Within;
+ T : aliased Task_Id;
To_Be_Freed : Task_Id;
- -- This is a list of ATCBs to be freed, after we have released
- -- all RTS locks. This is necessary because of the locking order
- -- rules, since the storage manager uses Global_Task_Lock.
+ -- This is a list of ATCBs to be freed, after we have released all RTS
+ -- locks. This is necessary because of the locking order rules, since
+ -- the storage manager uses Global_Task_Lock.
pragma Warnings (Off);
function Check_Unactivated_Tasks return Boolean;
(Self_ID.Deferral_Level > 0
or else not System.Restrictions.Abort_Allowed);
- -- Count how many active dependent tasks this master currently
- -- has, and record this in Wait_Count.
+ -- Count how many active dependent tasks this master currently has, and
+ -- record this in Wait_Count.
- -- This count should start at zero, since it is initialized to
- -- zero for new tasks, and the task should not exit the
- -- sleep-loops that use this count until the count reaches zero.
+ -- This count should start at zero, since it is initialized to zero for
+ -- new tasks, and the task should not exit the sleep-loops that use this
+ -- count until the count reaches zero.
-- While we're counting, if we run across any unactivated tasks that
-- belong to this master, we summarily terminate them as required by
-- Terminate unactivated (never-to-be activated) tasks
if C.Common.Activator = Self_ID and then C.Master_of_Task = CM then
+
pragma Assert (C.Common.State = Unactivated);
-- Usually, C.Common.Activator = Self_ID implies C.Master_of_Task
-- = CM. The only case where C is pending activation by this
-- Wait until dependent tasks are all terminated or ready to terminate.
-- While waiting, the task may be awakened if the task's priority needs
- -- changing, or this master is aborted. In the latter case, we want
- -- to abort the dependents, and resume waiting until Wait_Count goes
- -- to zero.
+ -- changing, or this master is aborted. In the latter case, we abort the
+ -- dependents, and resume waiting until Wait_Count goes to zero.
Write_Lock (Self_ID);
Self_ID.Common.State := Runnable;
Unlock (Self_ID);
- -- Dependents are all terminated or on terminate alternatives.
- -- Now, force those on terminate alternatives to terminate, by
- -- aborting them.
+ -- Dependents are all terminated or on terminate alternatives. Now,
+ -- force those on terminate alternatives to terminate, by aborting them.
pragma Assert (Check_Unactivated_Tasks);
-- rules prevent us from doing that without releasing the locks on C
-- and Self_ID. Releasing and retaking those locks would be wasteful
-- at best, and should not be considered further without more
- -- detailed analysis of potential concurrent accesses to the
- -- ATCBs of C and Self_ID.
+ -- detailed analysis of potential concurrent accesses to the ATCBs
+ -- of C and Self_ID.
- -- Count how many "alive" dependent tasks this master currently
- -- has, and record this in Wait_Count. This count should start at
- -- zero, since it is initialized to zero for new tasks, and the
- -- task should not exit the sleep-loops that use this count until
- -- the count reaches zero.
+ -- Count how many "alive" dependent tasks this master currently has,
+ -- and record this in Wait_Count. This count should start at zero,
+ -- since it is initialized to zero for new tasks, and the task should
+ -- not exit the sleep-loops that use this count until the count
+ -- reaches zero.
pragma Assert (Self_ID.Common.Wait_Count = 0);
-- fast as we can, so there is no point.
-- Remove terminated tasks from the list of Self_ID's dependents, but
- -- don't free their ATCBs yet, because of lock order restrictions,
- -- which don't allow us to call "free" or "malloc" while holding any
- -- other locks. Instead, we put those ATCBs to be freed onto a
- -- temporary list, called To_Be_Freed.
+ -- don't free their ATCBs yet, because of lock order restrictions, which
+ -- don't allow us to call "free" or "malloc" while holding any other
+ -- locks. Instead, we put those ATCBs to be freed onto a temporary list,
+ -- called To_Be_Freed.
if not Single_Lock then
Lock_RTS;
-- ???
-- The check "T.Common.Parent /= null ..." below is to prevent dangling
- -- references to terminated library-level tasks, which could
- -- otherwise occur during finalization of library-level objects.
- -- A better solution might be to hook task objects into the
- -- finalization chain and deallocate the ATCB when the task
- -- object is deallocated. However, this change is not likely
- -- to gain anything significant, since all this storage should
- -- be recovered en-masse when the process exits.
+ -- references to terminated library-level tasks, which could otherwise
+ -- occur during finalization of library-level objects. A better solution
+ -- might be to hook task objects into the finalization chain and
+ -- deallocate the ATCB when the task object is deallocated. However,
+ -- this change is not likely to gain anything significant, since all
+ -- this storage should be recovered en-masse when the process exits.
while To_Be_Freed /= null loop
T := To_Be_Freed;
To_Be_Freed := T.Common.All_Tasks_Link;
- -- ??? On SGI there is currently no Interrupt_Manager, that's
- -- why we need to check if the Interrupt_Manager_ID is null
+ -- ??? On SGI there is currently no Interrupt_Manager, that's why we
+ -- need to check if the Interrupt_Manager_ID is null.
- if T.Interrupt_Entry and Interrupt_Manager_ID /= null then
+ if T.Interrupt_Entry and then Interrupt_Manager_ID /= null then
declare
Detach_Interrupt_Entries_Index : constant Task_Entry_Index := 1;
-- Corresponds to the entry index of System.Interrupts.
if (T.Common.Parent /= null
and then T.Common.Parent.Common.Parent /= null)
- or else T.Master_of_Task > 3
+ or else T.Master_of_Task > Library_Task_Level
then
Initialization.Task_Lock (Self_ID);
-- ATCB. That would not cover the case of unactivated tasks. It also
-- would force us to keep the underlying thread around past termination,
-- since references to the ATCB are possible past termination.
+
-- Currently, we get rid of the thread as soon as the task terminates,
-- and let the parent recover the ATCB later.
-- that no longer have ATCBs. It is not clear how much this would gain,
-- since the user-level task object would still be occupying storage.
- -- Make next master level up active.
- -- We don't need to lock the ATCB, since the value is only updated by
- -- each task for itself.
+ -- Make next master level up active. We don't need to lock the ATCB,
+ -- since the value is only updated by each task for itself.
Self_ID.Master_Within := CM - 1;
end Vulnerable_Complete_Master;
Unlock_RTS;
end if;
- -- If Self_ID.Master_Within = Self_ID.Master_of_Task + 2
- -- we may have dependent tasks for which we need to wait.
- -- Otherwise, we can just exit.
+ -- If Self_ID.Master_Within = Self_ID.Master_of_Task + 2 we may have
+ -- dependent tasks for which we need to wait. Otherwise we just exit.
if Self_ID.Master_Within = Self_ID.Master_of_Task + 2 then
Vulnerable_Complete_Master (Self_ID);
-- Vulnerable_Free_Task --
--------------------------
- -- Recover all runtime system storage associated with the task T.
- -- This should only be called after T has terminated and will no
- -- longer be referenced.
+ -- Recover all runtime system storage associated with the task T. This
+ -- should only be called after T has terminated and will no longer be
+ -- referenced.
- -- For tasks created by an allocator that fails, due to an exception,
- -- it is called from Expunge_Unactivated_Tasks.
+ -- For tasks created by an allocator that fails, due to an exception, it
+ -- is called from Expunge_Unactivated_Tasks.
- -- For tasks created by elaboration of task object declarations it
- -- is called from the finalization code of the Task_Wrapper procedure.
- -- It is also called from Ada.Unchecked_Deallocation, for objects that
- -- are or contain tasks.
+ -- For tasks created by elaboration of task object declarations it is
+ -- called from the finalization code of the Task_Wrapper procedure. It is
+ -- also called from Ada.Unchecked_Deallocation, for objects that are or
+ -- contain tasks.
procedure Vulnerable_Free_Task (T : Task_Id) is
begin
Unlock_RTS;
end if;
+ Free_Entry_Names (T);
System.Task_Primitives.Operations.Finalize_TCB (T);
end Vulnerable_Free_Task;
-- Package elaboration code
begin
- -- Establish the Adafinal softlink
+ -- Establish the Adafinal oftlink
-- This is not done inside the central RTS initialization routine
-- to avoid with-ing this package from System.Tasking.Initialization.
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