------------------------------------------------------------------------------ -- -- -- 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 -- -- -- -- -- -- Copyright (C) 1991-2002 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 a Sun OS (FSU THREADS) version of this package -- PLEASE DO NOT add any dependences on other packages. ??? why not ??? -- This package is designed to work with or without tasking support. -- 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 with System.Error_Reporting; -- used for Shutdown with System.OS_Interface; -- used for various Constants, Signal and types package body System.Interrupt_Management is use Interfaces.C; use System.Error_Reporting; use System.OS_Interface; type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID; Exception_Interrupts : constant Interrupt_List := (SIGFPE, SIGILL, SIGSEGV); Unreserve_All_Interrupts : Interfaces.C.int; pragma Import (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts"); ----------------------- -- Local Subprograms -- ----------------------- procedure Notify_Exception (signo : Signal; info : access siginfo_t; context : access struct_sigcontext); -- This function identifies the Ada exception to be raised using -- the information when the system received a synchronous signal. -- Since this function is machine and OS dependent, different code -- has to be provided for different target. ---------------------- -- Notify_Exception -- ---------------------- -- The following code is intended for SunOS on Sparcstation. procedure Notify_Exception (signo : Signal; info : access siginfo_t; context : access struct_sigcontext) is begin -- 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. case signo is when SIGFPE => case info.si_code is when FPE_INTOVF_TRAP | FPE_STARTSIG_TRAP | FPE_INTDIV_TRAP | FPE_FLTDIV_TRAP | FPE_FLTUND_TRAP | FPE_FLTOPERR_TRAP | FPE_FLTOVF_TRAP => raise Constraint_Error; when others => pragma Assert (Shutdown ("Unexpected SIGFPE signal")); null; end case; when SIGILL => case info.si_code is when ILL_STACK | ILL_ILLINSTR_FAULT | ILL_PRIVINSTR_FAULT => raise Constraint_Error; when others => pragma Assert (Shutdown ("Unexpected SIGILL signal")); null; end case; when SIGSEGV => -- was caused by accessing a null pointer. -- ???? Origin of this code is unclear, may be broken ??? if context.sc_o0 in 0 .. 16#2000# then raise Constraint_Error; else raise Storage_Error; end if; when others => pragma Assert (Shutdown ("Unexpected signal")); null; end case; end Notify_Exception; --------------------------- -- Initialize_Interrupts -- --------------------------- -- Nothing needs to be done on this platform procedure Initialize_Interrupts is begin null; end Initialize_Interrupts; ------------------------- -- Package Elaboration -- ------------------------- begin declare act : aliased struct_sigaction; old_act : aliased struct_sigaction; mask : aliased sigset_t; Result : Interfaces.C.int; begin -- Need to call pthread_init very early because it is doing signal -- initializations. pthread_init; -- Change the following assignment to use another signal for task abort. -- For example, SIGTERM might be a good one if SIGABRT is required for -- use elsewhere. Abort_Task_Interrupt := SIGABRT; act.sa_handler := Notify_Exception'Address; -- Set sa_flags to SA_NODEFER so that during the handler execution -- we do not change the Signal_Mask to be masked for the Signal. -- This is a temporary fix to the problem that the Signal_Mask is -- not restored after the exception (longjmp) from the handler. -- The right fix should be made in sigsetjmp so that we save -- the Signal_Set and restore it after a longjmp. -- In that case, this field should be changed back to 0. ??? act.sa_flags := 16; Result := sigemptyset (mask'Access); pragma Assert (Result = 0); for J in Exception_Interrupts'Range loop Result := sigaddset (mask'Access, Signal (Exception_Interrupts (J))); pragma Assert (Result = 0); end loop; act.sa_mask := mask; for J in Exception_Interrupts'Range loop Keep_Unmasked (Exception_Interrupts (J)) := True; Result := sigaction (Signal (Exception_Interrupts (J)), act'Unchecked_Access, old_act'Unchecked_Access); pragma Assert (Result = 0); end loop; Keep_Unmasked (Abort_Task_Interrupt) := True; Keep_Unmasked (SIGALRM) := True; Keep_Unmasked (SIGSTOP) := True; Keep_Unmasked (SIGKILL) := True; -- By keeping SIGINT unmasked, allow the user to do a Ctrl-C, but at -- the same time, disable the ability of handling this signal using -- package Ada.Interrupts. -- The pragma Unreserve_All_Interrupts allows the user the ability to -- change this behavior. if Unreserve_All_Interrupts = 0 then Keep_Unmasked (SIGINT) := True; end if; -- Reserve this not to interfere with thread scheduling -- ??? consider adding this to interrupt exceptions -- Keep_Unmasked (SIGALRM) := True; -- An earlier version had a comment about SIGALRM needing to be unmasked -- in at least one thread for cond_timedwait to work. -- It is unclear whether this is True for Solaris threads, FSU threads, -- both, or maybe just an old version of FSU threads. ???? -- Following signals should not be disturbed. Found by experiment Keep_Unmasked (SIGEMT) := True; Keep_Unmasked (SIGCHLD) := True; -- We do not have Signal 0 in reality. We just use this value -- to identify not existing signals (see s-intnam.ads). Therefore, -- Signal 0 should not be used in all signal related operations hence -- mark it as reserved. Reserve := Reserve or Keep_Unmasked or Keep_Masked; Reserve (0) := True; end; end System.Interrupt_Management;