------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T -- -- -- -- B o d y -- -- -- -- $Revision: 1.1.1.1 $ -- -- -- Copyright (C) 1991-2001 Florida State University -- -- -- -- 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- -- -- 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, 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, -- -- 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. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- -- State University (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This is the VxWorks version of this package. -- It is likely to need tailoring to fit each operating system -- and machine architecture. -- PLEASE DO NOT add any dependences on other packages. -- This package is designed to work with or without tasking support. -- See the other warnings in the package specification before making -- any modifications to this file. -- Make a careful study of all signals available under the OS, -- to see which need to be reserved, kept always unmasked, -- or kept always unmasked. -- Be on the lookout for special signals that -- may be used by the thread library. with Interfaces.C; -- used for int and other types with System.Error_Reporting; pragma Warnings (Off, System.Error_Reporting); -- used for Shutdown with System.OS_Interface; -- used for various Constants, Signal and types with Unchecked_Conversion; package body System.Interrupt_Management is use Interfaces.C; use System.Error_Reporting; use System.OS_Interface; function To_Isr is new Unchecked_Conversion (Long_Integer, isr_address); type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID; Exception_Interrupts : constant Interrupt_List := (SIGFPE, SIGILL, SIGSEGV, SIGBUS); -- Keep these variables global so that they are initialized only once. Exception_Action : aliased struct_sigaction; Default_Action : aliased struct_sigaction; -- ????? Use these horrible imports here to solve elaboration order -- problems. type Task_Id is access all Integer; Interrupt_ID_Map : array (Interrupt_ID) of Task_Id; pragma Import (Ada, Interrupt_ID_Map, "system__task_primitives__interrupt_operations__interrupt_id_map"); ---------------------- -- Notify_Exception -- ---------------------- procedure Notify_Exception (signo : Signal); -- Identify the Ada exception to be raised using -- the information when the system received a synchronous signal. procedure Notify_Exception (signo : Signal) is Mask : aliased sigset_t; Result : Interfaces.C.int; My_Id : pthread_t; begin -- VxWorks will always mask out the signal during the signal -- handler and will reenable it on a longjmp. GNAT does -- not generate a longjmp to return from a signal handler -- so the signal will still be masked unless we unmask it. Result := pthread_sigmask (SIG_SETMASK, null, Mask'Unchecked_Access); Result := sigdelset (Mask'Access, signo); Result := pthread_sigmask (SIG_SETMASK, Mask'Unchecked_Access, null); -- VxWorks will suspend the task when it gets a hardware -- exception. We take the liberty of resuming the task -- for the application. My_Id := taskIdSelf; if taskIsSuspended (My_Id) /= 0 then Result := taskResume (My_Id); end if; -- As long as we are using a longjmp to return control to the -- exception handler on the runtime stack, we are safe. The original -- signal mask (the one we had before coming into this signal catching -- function) will be restored by the longjmp. Therefore, raising -- an exception in this handler should be a safe operation. -- Check that treatment of exception propagation here -- is consistent with treatment of the abort signal in -- System.Task_Primitives.Operations. -- How can SIGSEGV be split into constraint and storage errors? -- What should SIGILL really raise ? Some implementations have -- codes for different types of SIGILL and some raise Storage_Error. -- What causes SIGBUS and should it be caught? -- Peter Burwood case signo is when SIGFPE => raise Constraint_Error; when SIGILL => raise Constraint_Error; when SIGSEGV => raise Program_Error; when SIGBUS => raise Program_Error; when others => pragma Assert (Shutdown ("Unexpected signal")); null; end case; end Notify_Exception; ------------------- -- Notify_Signal -- ------------------- -- VxWorks needs a special casing here. Each VxWorks task has a completely -- separate signal handling, so the usual signal masking can't work. -- This idea is to handle all the signals in all the tasks, and when -- such a signal occurs, redirect it to the dedicated task (if any) or -- reraise it. procedure Notify_Signal (signo : Signal); procedure Notify_Signal (signo : Signal) is Mask : aliased sigset_t; Result : Interfaces.C.int; My_Id : pthread_t; old_isr : isr_address; function Get_Thread_Id (T : Task_Id) return pthread_t; pragma Import (Ada, Get_Thread_Id, "system__task_primitives__operations__get_thread_id"); begin -- VxWorks will always mask out the signal during the signal -- handler and will reenable it on a longjmp. GNAT does -- not generate a longjmp to return from a signal handler -- so the signal will still be masked unless we unmask it. Result := pthread_sigmask (SIG_SETMASK, null, Mask'Unchecked_Access); Result := sigdelset (Mask'Access, signo); Result := pthread_sigmask (SIG_SETMASK, Mask'Unchecked_Access, null); -- VxWorks will suspend the task when it gets a hardware -- exception. We take the liberty of resuming the task -- for the application. My_Id := taskIdSelf; if taskIsSuspended (My_Id) /= 0 then Result := taskResume (My_Id); end if; -- ??? Need a lock around this, in case the handler is detached -- between the two following statements. if Interrupt_ID_Map (Interrupt_ID (signo)) /= null then Result := kill (Get_Thread_Id (Interrupt_ID_Map (Interrupt_ID (signo))), Signal (signo)); else old_isr := c_signal (signo, To_Isr (SIG_DFL)); Result := kill (My_Id, Signal (signo)); end if; end Notify_Signal; --------------------------- -- Initialize_Interrupts -- --------------------------- -- Since there is no signal inheritance between VxWorks tasks, we need -- to initialize signal handling in each task. procedure Initialize_Interrupts is old_act : aliased struct_sigaction; Result : Interfaces.C.int; begin for J in Interrupt_ID'First + 1 .. Interrupt_ID'Last loop if J /= Abort_Task_Interrupt then Result := sigaction (Signal (J), Default_Action'Access, old_act'Unchecked_Access); pragma Assert (Result = 0); end if; end loop; for J in Exception_Interrupts'Range loop Keep_Unmasked (Exception_Interrupts (J)) := True; Result := sigaction (Signal (Exception_Interrupts (J)), Exception_Action'Access, old_act'Unchecked_Access); pragma Assert (Result = 0); end loop; end Initialize_Interrupts; begin declare mask : aliased sigset_t; default_mask : aliased sigset_t; Result : Interfaces.C.int; begin -- The VxWorks POSIX threads library currently needs initialization. -- We wish it could be in System.OS_Interface, but that would -- cause an elaboration problem. pthread_init; Abort_Task_Interrupt := SIGABRT; -- Change this if you want to use another signal for task abort. -- SIGTERM might be a good one. Exception_Action.sa_handler := Notify_Exception'Address; Default_Action.sa_handler := Notify_Signal'Address; Exception_Action.sa_flags := SA_SIGINFO + SA_ONSTACK; Default_Action.sa_flags := SA_SIGINFO + SA_ONSTACK; -- Send us extra signal information (SA_SIGINFO) on the -- stack (SA_ONSTACK). -- There is no SA_NODEFER in VxWorks. The signal mask is -- restored after a longjmp so the SA_NODEFER option is -- not needed. - Dan Eischen Result := sigemptyset (mask'Access); pragma Assert (Result = 0); Result := sigemptyset (default_mask'Access); pragma Assert (Result = 0); for J in Interrupt_ID'First + 1 .. Interrupt_ID'Last loop Result := sigaddset (default_mask'Access, Signal (J)); pragma Assert (Result = 0); end loop; for J in Exception_Interrupts'Range loop Result := sigaddset (mask'Access, Signal (Exception_Interrupts (J))); pragma Assert (Result = 0); Result := sigdelset (default_mask'Access, Signal (Exception_Interrupts (J))); pragma Assert (Result = 0); end loop; Exception_Action.sa_mask := mask; Default_Action.sa_mask := default_mask; -- Initialize_Interrupts is called for each task in Enter_Task Keep_Unmasked (Abort_Task_Interrupt) := True; Reserve := Reserve or Keep_Unmasked or Keep_Masked; Reserve (0) := True; -- We do not have Signal 0 in reality. We just use this value -- to identify non-existent signals (see s-intnam.ads). Therefore, -- Signal 0 should not be used in all signal related operations hence -- mark it as reserved. end; end System.Interrupt_Management;