diff options
Diffstat (limited to 'gcc/ada/s-tassta.adb')
| -rw-r--r-- | gcc/ada/s-tassta.adb | 304 |
1 files changed, 158 insertions, 146 deletions
diff --git a/gcc/ada/s-tassta.adb b/gcc/ada/s-tassta.adb index 6e73cde6b80..8fc01030702 100644 --- a/gcc/ada/s-tassta.adb +++ b/gcc/ada/s-tassta.adb @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2002, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2003, 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- -- @@ -26,8 +26,8 @@ -- 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. It is -- --- now maintained by Ada Core Technologies, Inc. (http://www.gnat.com). -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ @@ -39,7 +39,6 @@ with Ada.Exceptions; -- used for Raise_Exception with System.Tasking.Debug; -pragma Warnings (Off, System.Tasking.Debug); -- used for enabling tasking facilities with gdb with System.Address_Image; @@ -52,7 +51,6 @@ with System.Parameters; with System.Task_Info; -- used for Task_Info_Type --- Task_Image_Type with System.Task_Primitives.Operations; -- used for Finalize_Lock @@ -99,9 +97,6 @@ with System.OS_Primitives; with System.Finalization_Implementation; -- Used for System.Finalization_Implementation.Finalize_Global_List -with Interfaces.C; --- Used for type Unsigned. - with System.Secondary_Stack; -- used for SS_Init; @@ -135,11 +130,9 @@ package body System.Tasking.Stages is -- Local Subprograms -- ----------------------- - procedure Notify_Exception - (Self_Id : Task_ID; - Excep : Exception_Occurrence); - -- This procedure will output the task ID and the exception information, - -- including traceback if available. + procedure Trace_Unhandled_Exception_In_Task (Self_Id : Task_ID); + -- This procedure outputs the task specific message for exception + -- tracing purposes. procedure Task_Wrapper (Self_ID : Task_ID); -- This is the procedure that is called by the GNULL from the @@ -184,10 +177,6 @@ package body System.Tasking.Stages is -- Different code is used at master completion, in Terminate_Dependents, -- due to a need for tighter synchronization with the master. - procedure Terminate_Task (Self_ID : Task_ID); - -- Terminate the calling task. - -- This should only be called by the Task_Wrapper procedure. - ---------------------- -- Abort_Dependents -- ---------------------- @@ -339,10 +328,10 @@ package body System.Tasking.Stages is (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; @@ -404,9 +393,8 @@ package body System.Tasking.Stages is C := P; end loop; - -- Wait for the activated tasks to complete activation. - -- It is unsafe to abort any of these tasks until the count goes to - -- zero. + -- Wait for the activated tasks to complete activation. It is + -- unsafe to abort any of these tasks until the count goes to zero. loop Initialization.Poll_Base_Priority_Change (Self_ID); @@ -421,7 +409,7 @@ package body System.Tasking.Stages is Unlock_RTS; end if; - -- Remove the tasks from the chain. + -- Remove the tasks from the chain Chain_Access.T_ID := null; Initialization.Undefer_Abort_Nestable (Self_ID); @@ -467,7 +455,7 @@ package body System.Tasking.Stages is --------------------- procedure Complete_Master is - Self_ID : Task_ID := STPO.Self; + Self_ID : constant Task_ID := STPO.Self; begin pragma Assert (Self_ID.Deferral_Level > 0); @@ -479,7 +467,7 @@ package body System.Tasking.Stages is -- Complete_Task -- ------------------- - -- See comments on Vulnerable_Complete_Task for details. + -- See comments on Vulnerable_Complete_Task for details procedure Complete_Task is Self_ID : constant Task_ID := STPO.Self; @@ -488,8 +476,8 @@ package body System.Tasking.Stages is Vulnerable_Complete_Task (Self_ID); - -- All of our dependents have terminated. - -- Never undefer abort again! + -- All of our dependents have terminated. Never undefer abort again! + end Complete_Task; ----------------- @@ -509,13 +497,14 @@ package body System.Tasking.Stages is Discriminants : System.Address; Elaborated : Access_Boolean; Chain : in out Activation_Chain; - Task_Image : System.Task_Info.Task_Image_Type; + Task_Image : String; Created_Task : out Task_ID) is T, P : Task_ID; Self_ID : constant Task_ID := STPO.Self; Success : Boolean; Base_Priority : System.Any_Priority; + Len : Natural; begin pragma Debug @@ -527,7 +516,7 @@ package body System.Tasking.Stages is Base_Priority := System.Any_Priority (Priority); end if; - -- Find parent P of new Task, via master level number. + -- Find parent P of new Task, via master level number P := Self_ID; @@ -595,7 +584,29 @@ package body System.Tasking.Stages is T.Entry_Calls (L).Level := L; end loop; - T.Common.Task_Image := Task_Image; + if Task_Image'Length = 0 then + T.Common.Task_Image_Len := 0; + else + Len := 1; + T.Common.Task_Image (1) := Task_Image (Task_Image'First); + + for J in Task_Image'First + 1 .. Task_Image'Last loop + + -- Remove unwanted blank space generated by 'Image + + if Task_Image (J) /= ' ' + or else Task_Image (J - 1) /= '(' + then + Len := Len + 1; + T.Common.Task_Image (Len) := Task_Image (J); + + exit when Len = T.Common.Task_Image'Last; + end if; + end loop; + + T.Common.Task_Image_Len := Len; + end if; + Unlock (Self_ID); Unlock_RTS; @@ -655,6 +666,7 @@ package body System.Tasking.Stages is -- ??? -- 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. C := Chain.T_ID; @@ -742,10 +754,9 @@ package body System.Tasking.Stages is Unlock_RTS; end if; - -- 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. + -- 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. Write_Lock (Self_ID); @@ -774,7 +785,7 @@ package body System.Tasking.Stages is Unlock_RTS; end if; - -- Complete the environment task. + -- Complete the environment task Vulnerable_Complete_Task (Self_ID); @@ -807,14 +818,11 @@ package body System.Tasking.Stages is begin if T.Common.State = Terminated then + -- It is not safe to call Abort_Defer or Write_Lock at this stage Initialization.Task_Lock (Self_Id); - if T.Common.Task_Image /= null then - Free_Task_Image (T.Common.Task_Image); - end if; - Lock_RTS; Initialization.Remove_From_All_Tasks_List (T); Unlock_RTS; @@ -832,43 +840,6 @@ package body System.Tasking.Stages is end if; end Free_Task; - ---------------------- - -- Notify_Exception -- - ---------------------- - - procedure Notify_Exception - (Self_Id : Task_ID; - Excep : Exception_Occurrence) - is - procedure To_Stderr (S : String); - pragma Import (Ada, To_Stderr, "__gnat_to_stderr"); - - use System.Task_Info; - use System.Soft_Links; - - function To_Address is new - Unchecked_Conversion (Task_ID, System.Address); - - function Tailored_Exception_Information - (E : Exception_Occurrence) return String; - pragma Import - (Ada, Tailored_Exception_Information, - "__gnat_tailored_exception_information"); - - begin - To_Stderr ("task "); - - if Self_Id.Common.Task_Image /= null then - To_Stderr (Self_Id.Common.Task_Image.all); - To_Stderr ("_"); - end if; - - To_Stderr (System.Address_Image (To_Address (Self_Id))); - To_Stderr (" terminated by unhandled exception"); - To_Stderr ((1 => ASCII.LF)); - To_Stderr (Tailored_Exception_Information (Excep)); - end Notify_Exception; - ------------------ -- Task_Wrapper -- ------------------ @@ -880,36 +851,13 @@ package body System.Tasking.Stages is -- data. Task finalization is done by Complete_Task, which is called from -- an at-end handler that the compiler generates. - -- The variable ID in the task wrapper is used to implement the Self - -- function on targets where there is a fast way to find the stack base - -- of the current thread, since it should be at a fixed offset from the - -- stack base. - - -- The variable Magic_Number is also used in such implementations - -- of Self, to check whether the current task is an Ada task, as - -- compared to other-language threads. - - -- Both act as constants, once initialized, but need to be marked as - -- volatile or aliased to prevent the compiler from optimizing away the - -- storage. See System.Task_Primitives.Operations.Self for more info. - procedure Task_Wrapper (Self_ID : Task_ID) is - ID : Task_ID := Self_ID; - pragma Volatile (ID); - -- Do not delete this variable. - -- In some targets, we need this variable to implement a fast Self. - - Magic_Number : Interfaces.C.unsigned := 16#ADAADAAD#; - pragma Volatile (Magic_Number); - -- We use this to verify that we are looking at an Ada task, - -- inside of System.Task_Primitives.Operations.Self. - use type System.Parameters.Size_Type; use type SSE.Storage_Offset; use System.Standard_Library; Secondary_Stack : aliased SSE.Storage_Array - (1 .. ID.Common.Compiler_Data.Pri_Stack_Info.Size * + (1 .. Self_ID.Common.Compiler_Data.Pri_Stack_Info.Size * SSE.Storage_Offset (Parameters.Sec_Stack_Ratio) / 100); Secondary_Stack_Address : System.Address := Secondary_Stack'Address; @@ -917,63 +865,83 @@ package body System.Tasking.Stages is pragma Assert (Self_ID.Deferral_Level = 1); if not Parameters.Sec_Stack_Dynamic then - ID.Common.Compiler_Data.Sec_Stack_Addr := Secondary_Stack'Address; + Self_ID.Common.Compiler_Data.Sec_Stack_Addr := + Secondary_Stack'Address; SST.SS_Init (Secondary_Stack_Address, Integer (Secondary_Stack'Last)); end if; - -- Set the guard page at the bottom of the stack. - -- The call to unprotect the page is done in Terminate_Task + -- Set the guard page at the bottom of the stack. The call to + -- unprotect the page is done in Terminate_Task 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 Self_ID.LL.Thread + -- 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 Enter_Task (Self_ID); -- We lock RTS_Lock to wait for activator to finish activating -- the rest of the chain, so that everyone in the chain comes out -- in priority order. + -- This also protects the value of - -- Self_ID.Common.Activator.Common.Wait_Count. + -- Self_ID.Common.Activator.Common.Wait_Count. Lock_RTS; Unlock_RTS; begin -- We are separating the following portion of the code in order to - -- place the exception handlers in a different block. - -- In this way we do not call Set_Jmpbuf_Address (which needs - -- Self) before we set Self in Enter_Task + -- place the exception handlers in a different block. In this way, + -- we do not call Set_Jmpbuf_Address (which needs Self) before we + -- set Self in Enter_Task - -- Call the task body procedure. + -- Call the task body procedure -- The task body is called with abort still deferred. That -- eliminates a dangerous window, for which we had to patch-up in -- Terminate_Task. + -- During the expansion of the task body, we insert an RTS-call -- to Abort_Undefer, at the first point where abort should be -- allowed. Self_ID.Common.Task_Entry_Point (Self_ID.Common.Task_Arg); - Terminate_Task (Self_ID); + Initialization.Defer_Abort_Nestable (Self_ID); exception + -- We can't call Terminate_Task in the exception handlers below, + -- since there may be (e.g. in the case of GCC exception handling) + -- clean ups associated with the exception handler that need to + -- access task specific data. + + -- Defer abortion so that this task can't be aborted while exiting + when Standard'Abort_Signal => - Terminate_Task (Self_ID); + Initialization.Defer_Abort_Nestable (Self_ID); when others => -- ??? Using an E : others here causes CD2C11A to fail on -- DEC Unix, see 7925-005. + Initialization.Defer_Abort_Nestable (Self_ID); + + -- Perform the task specific exception tracing duty. We handle + -- these outputs here and not in the common notification routine + -- because we need access to tasking related data and we don't + -- want to drag dependencies against tasking related units in the + -- the common notification units. Additionally, no trace is ever + -- triggered from the common routine for the Unhandled_Raise case + -- in tasks, since an exception never appears unhandled in this + -- context because of this handler. + if Exception_Trace = Unhandled_Raise then - Notify_Exception (Self_ID, SSL.Get_Current_Excep.all.all); + Trace_Unhandled_Exception_In_Task (Self_ID); end if; - - Terminate_Task (Self_ID); end; + + Terminate_Task (Self_ID); end Task_Wrapper; -------------------- @@ -985,12 +953,11 @@ package body System.Tasking.Stages is -- 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 last thing - -- done before the call to Exit_Task. The trouble is that we have another - -- step that we also want to postpone to the very end, i.e., calling - -- SSL.Destroy_TSD. We have to postpone that until the end because - -- compiler-generated code is likely to try to access that data at just - -- about any point. + -- 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 + -- also want to postpone to the very end, i.e., calling SSL.Destroy_TSD. + -- We have to postpone that until the end because compiler-generated code + -- is likely to try to access that data at just about any point. -- We can't call Destroy_TSD while we are holding any other locks, because -- it locks Global_Task_Lock, and our deadlock prevention rules require @@ -1008,8 +975,11 @@ package body System.Tasking.Stages is procedure Terminate_Task (Self_ID : Task_ID) is Environment_Task : constant Task_ID := STPO.Environment_Task; + Master_of_Task : Integer; begin + Debug.Task_Termination_Hook; + if Runtime_Traces then Send_Trace_Info (T_Terminate); end if; @@ -1029,10 +999,12 @@ package body System.Tasking.Stages is Lock_RTS; end if; + Master_of_Task := Self_ID.Master_of_Task; + -- Check if the current task is an independent task -- If so, decrement the Independent_Task_Count value. - if Self_ID.Master_of_Task = 2 then + if Master_of_Task = 2 then if Single_Lock then Utilities.Independent_Task_Count := Utilities.Independent_Task_Count - 1; @@ -1045,7 +1017,7 @@ package body System.Tasking.Stages is end if; end if; - -- Unprotect the guard page if needed. + -- Unprotect the guard page if needed Stack_Guard (Self_ID, False); @@ -1064,7 +1036,9 @@ package body System.Tasking.Stages is -- past this point, this thread must assume that the ATCB -- has been deallocated. It should not be accessed again. - STPO.Exit_Task; + if Master_of_Task > 0 then + STPO.Exit_Task; + end if; end Terminate_Task; ---------------- @@ -1072,8 +1046,8 @@ package body System.Tasking.Stages is ---------------- function Terminated (T : Task_ID) return Boolean is + Self_ID : constant Task_ID := STPO.Self; Result : Boolean; - Self_ID : Task_ID := STPO.Self; begin Initialization.Defer_Abort_Nestable (Self_ID); @@ -1094,6 +1068,49 @@ package body System.Tasking.Stages is return Result; end Terminated; + ---------------------------------------- + -- Trace_Unhandled_Exception_In_Task -- + ---------------------------------------- + + procedure Trace_Unhandled_Exception_In_Task (Self_Id : Task_ID) is + procedure To_Stderr (S : String); + pragma Import (Ada, To_Stderr, "__gnat_to_stderr"); + + use System.Task_Info; + use System.Soft_Links; + use System.Standard_Library; + + function To_Address is new + Unchecked_Conversion (Task_ID, System.Address); + + function Tailored_Exception_Information + (E : Exception_Occurrence) return String; + pragma Import + (Ada, Tailored_Exception_Information, + "__gnat_tailored_exception_information"); + + Excep : Exception_Occurrence_Access := SSL.Get_Current_Excep.all; + + begin + -- This procedure is called by the task outermost handler in + -- Task_Wrapper below, so only once the task stack has been fully + -- unwound. The common notification routine has been called at the + -- raise point already. + + To_Stderr ("task "); + + if Self_Id.Common.Task_Image_Len /= 0 then + To_Stderr + (Self_Id.Common.Task_Image (1 .. Self_Id.Common.Task_Image_Len)); + To_Stderr ("_"); + end if; + + To_Stderr (System.Address_Image (To_Address (Self_Id))); + To_Stderr (" terminated by unhandled exception"); + To_Stderr ((1 => ASCII.LF)); + To_Stderr (Tailored_Exception_Information (Excep.all)); + end Trace_Unhandled_Exception_In_Task; + ------------------------------------ -- Vulnerable_Complete_Activation -- ------------------------------------ @@ -1114,14 +1131,13 @@ package body System.Tasking.Stages is pragma Assert (Self_ID.Common.Activator /= null); - -- Remove dangling reference to Activator, - -- since a task may outlive its activator. + -- Remove dangling reference to Activator, since a task may + -- outlive its activator. Self_ID.Common.Activator := null; - -- Wake up the activator, if it is waiting for a chain - -- of tasks to activate, and we are the last in the chain - -- to complete activation + -- Wake up the activator, if it is waiting for a chain of tasks to + -- activate, and we are the last in the chain to complete activation. if Activator.Common.State = Activator_Sleep then Activator.Common.Wait_Count := Activator.Common.Wait_Count - 1; @@ -1131,10 +1147,10 @@ package body System.Tasking.Stages is end if; end if; - -- The activator raises a Tasking_Error if any task - -- it is activating is completed before the activation is - -- done. However, if the reason for the task completion is - -- an abortion, we do not raise an exception. ARM 9.2(5). + -- The activator raises a Tasking_Error if any task it is activating + -- is completed before the activation is done. However, if the reason + -- for the task completion is an abortion, we do not raise an exception. + -- See RM 9.2(5). if not Self_ID.Callable and then Self_ID.Pending_ATC_Level /= 0 then Activator.Common.Activation_Failed := True; @@ -1161,7 +1177,7 @@ package body System.Tasking.Stages is procedure Vulnerable_Complete_Master (Self_ID : Task_ID) is C : Task_ID; P : Task_ID; - CM : Master_Level := Self_ID.Master_Within; + CM : constant Master_Level := Self_ID.Master_Within; T : aliased Task_ID; To_Be_Freed : Task_ID; @@ -1455,7 +1471,7 @@ package body System.Tasking.Stages is if T.Interrupt_Entry and Interrupt_Manager_ID /= null then declare - Detach_Interrupt_Entries_Index : Task_Entry_Index := 1; + Detach_Interrupt_Entries_Index : constant Task_Entry_Index := 1; -- Corresponds to the entry index of System.Interrupts. -- Interrupt_Manager.Detach_Interrupt_Entries. -- Be sure to update this value when changing @@ -1592,8 +1608,7 @@ package body System.Tasking.Stages is procedure Vulnerable_Free_Task (T : Task_ID) is begin - pragma Debug - (Debug.Trace ("Vulnerable_Free_Task", T, 'C')); + pragma Debug (Debug.Trace (Self, "Vulnerable_Free_Task", 'C', T)); if Single_Lock then Lock_RTS; @@ -1607,15 +1622,12 @@ package body System.Tasking.Stages is Unlock_RTS; end if; - if T.Common.Task_Image /= null then - Free_Task_Image (T.Common.Task_Image); - end if; - System.Task_Primitives.Operations.Finalize_TCB (T); end Vulnerable_Free_Task; begin -- Establish the Adafinal softlink. + -- This is not done inside the central RTS initialization routine -- to avoid with-ing this package from System.Tasking.Initialization. |