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Diffstat (limited to 'gcc/ada/s-tasdeb.ads')
| -rw-r--r-- | gcc/ada/s-tasdeb.ads | 173 |
1 files changed, 57 insertions, 116 deletions
diff --git a/gcc/ada/s-tasdeb.ads b/gcc/ada/s-tasdeb.ads index a98575a170c..fa886e7366f 100644 --- a/gcc/ada/s-tasdeb.ads +++ b/gcc/ada/s-tasdeb.ads @@ -6,7 +6,7 @@ -- -- -- S p e c -- -- -- --- Copyright (C) 1997-2001, Free Software Foundation, Inc. -- +-- Copyright (C) 1997-2002, 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- -- @@ -27,150 +27,91 @@ -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- --- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- This package encapsulates all direct interfaces to task debugging services --- that are needed by gdb with gnat mode (1.17 and higher) +-- that are needed by gdb with gnat mode. -with Interfaces.C; with System.Tasking; with System.OS_Interface; package System.Tasking.Debug is - subtype int is Interfaces.C.int; - subtype unsigned_long is Interfaces.C.unsigned_long; - - package ST renames System.Tasking; - - Known_Tasks : array (0 .. 999) of Task_ID; - -- Global array of tasks read by gdb, and updated by - -- Create_Task and Finalize_TCB - - procedure Task_Creation_Hook (Thread : OS_Interface.Thread_Id); - -- This procedure is used to notify VxGdb of task's creation. - -- It must be called by the task's creator. - - procedure Task_Termination_Hook; - -- This procedure is used to notify VxGdb of task's termination. - - function Self return Task_ID; - -- return system ID of current task + ------------------------------------------ + -- Application-level debugging routines -- + ------------------------------------------ procedure List_Tasks; -- Print a list of all the known Ada tasks with abbreviated state - -- information, one-per-line, to the standard output file + -- information, one-per-line, to the standard error file. procedure Print_Current_Task; - procedure Print_Task_Info_Header; + -- Write information about current task, in hexadecimal, as one line, to + -- the standard error file. + procedure Print_Task_Info (T : Task_ID); - -- Write TASK_ID of current task, in hexadecimal, as one line, to - -- the standard output file - -- - -- Beware that Print_Current_Task may print garbage during an early - -- stage of activation. There is a small window where a task is just - -- initializing itself and has not yet recorded its own task Id. - -- - -- Beware that Print_Current_Task will either not work at all or print - -- garbage if it has interrupted a thread of control that does not - -- correspond to any Ada task. For example, this is could happen if - -- the debugger interrupts a signal handler that is using an alternate - -- stack, or interrupts the dispatcher in the underlying thread - -- implementation. - - procedure Set_User_State (Value : Integer); - - procedure Print_Accept_Info (T : Task_ID); + -- Similar to Print_Current_Task, for a given task. - procedure Trace - (Self_ID : Task_ID; - Msg : String; - Other_ID : Task_ID; - Flag : Character); + procedure Set_User_State (Value : Long_Integer); + -- Set user state value in the current task. + -- This state will be displayed when calling List_Tasks or + -- Print_Current_Task. It is useful for setting task specific state. - procedure Trace - (Self_ID : Task_ID; - Msg : String; - Flag : Character); + function Get_User_State return Long_Integer; + -- Return the user state for the current task. - procedure Trace - (Msg : String; - Flag : Character); + ------------------------- + -- General GDB support -- + ------------------------- - procedure Trace - (Msg : String; - Other_ID : Task_ID; - Flag : Character); + Known_Tasks : array (0 .. 999) of Task_ID; + -- Global array of tasks read by gdb, and updated by + -- Create_Task and Finalize_TCB - procedure Set_Trace - (Flag : Character; - Value : Boolean := True); + ---------------------------------- + -- VxWorks specific GDB support -- + ---------------------------------- + + -- Although the following routines are implemented in a target independent + -- manner, only VxWorks currently uses them. - function Image (T : Task_ID) return String; + procedure Task_Creation_Hook (Thread : OS_Interface.Thread_Id); + -- This procedure is used to notify GDB of task's creation. + -- It must be called by the task's creator. + + procedure Task_Termination_Hook; + -- This procedure is used to notify GDB of task's termination. procedure Suspend_All_Tasks (Thread_Self : OS_Interface.Thread_Id); -- Suspend all the tasks except the one whose associated thread is -- Thread_Self by traversing All_Tasks_Lists and calling - -- System.Task_Primitives.Operations.Suspend_Task - -- Such functionality is needed by gdb on some targets (e.g VxWorks) - -- Warning: for efficiency purposes, there is no locking. + -- System.Task_Primitives.Operations.Suspend_Task. procedure Resume_All_Tasks (Thread_Self : OS_Interface.Thread_Id); -- Resume all the tasks except the one whose associated thread is -- Thread_Self by traversing All_Tasks_Lists and calling - -- System.Task_Primitives.Operations.Continue_Task - -- Such functionality is needed by gdb on some targets (e.g VxWorks) - -- Warning: for efficiency purposes, there is no locking. + -- System.Task_Primitives.Operations.Continue_Task. -end System.Tasking.Debug; + ------------------------------- + -- Run-time tracing routines -- + ------------------------------- ------------------------------ --- Use of These Functions -- ------------------------------ - --- Calling complicated functions from the debugger is generally pretty --- risky, especially in a multithreaded program. - --- The debugger may interrupt something that is not an Ada task, --- within the thread implementation, and which is not async-safe. - --- For example, under Solaris, it can interrupt code in "_dynamiclwps", --- which seems to serve as dispatcher when all the user threads are --- suspended. By experience, we have found that one cannot safely --- do certain things, apparently including calls to thread primitives --- from the debugger if the debugger has interrupted at one of these --- unsafe points. In general, if you interrupt a running program --- asynchronously (e.g. via control-C), it will not be safe to --- call the subprograms in this package. - ------------------ --- Future work -- ------------------ - --- It would be nice to be able to tell whether execution has been --- interrupted in an Ada task. A heuristic way of checking this would --- be if we added to the Ada TCB a component that always contains a --- constant value that is unlikely to occur accidentally in code or --- data. We could then check this in the debugger-callable subprograms, --- and simply return an error code if it looks unsafe to proceed. - --- ??? --- Recently we have added such a marker as a local variable of the --- task-wrapper routine. This allows Self to generate a fake ATCB for --- non-Ada threads of control. Given this capability, it is probably --- time to revisit the issue above. - --- DEADLOCK - --- We follow a simple rule here to avoid deadlock: - --- We do not use any locks in functions called by gdb, and we do not --- traverse linked lists. --- --- The use of an array (Known_Tasks) has many advantages: - --- - Easy and fast to examine; --- - No risk of dangling references (to the next element) when traversing --- the array. + procedure Trace + (Self_Id : Task_ID; + Msg : String; + Flag : Character; + Other_Id : Task_ID := null); + -- If traces for Flag are enabled, display on Standard_Error a given + -- message for the current task. Other_Id is an optional second task id + -- to display. + + procedure Set_Trace + (Flag : Character; + Value : Boolean := True); + -- Enable or disable tracing for Flag. + -- By default, flags in the range 'A' .. 'Z' are disabled, others are + -- enabled. + +end System.Tasking.Debug; |