signal handling made more generic

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@290 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/init.c

@@ -874,7 +874,7 @@ InitCodes(void)
   AtomArrow = LookupAtom("->");
   heap_regs->atom_assert = LookupAtom(":-");
   heap_regs->atom_alarm = LookupAtom("$alarm");
-#if USE_SIGACTION
+#if HAVE_SIGACTION
   heap_regs->atom_sig_pending = LookupAtom("$sig_pending");
 #endif
   AtomBraces = LookupAtom("{}");

C/save.c

@@ -1050,7 +1050,7 @@ restore_codes(void)
   heap_regs->atom_read = AtomAdjust(heap_regs->atom_read);
   heap_regs->atom_repeat = AtomAdjust(heap_regs->atom_repeat);
   heap_regs->atom_restore_regs = AtomAdjust(heap_regs->atom_restore_regs);
-#if USE_SIGACTION
+#if HAVE_SIGACTION
   heap_regs->atom_sig_pending = AtomAdjust(heap_regs->atom_sig_pending);
 #endif
   heap_regs->atom_stack_free = AtomAdjust(heap_regs->atom_stack_free);

C/sysbits.c

@@ -823,7 +823,6 @@ STATIC_PROTO (void InitSignals, (void));
 
 STATIC_PROTO (void HandleSIGSEGV, (int, siginfo_t   *, ucontext_t *));
 STATIC_PROTO (void HandleMatherr,  (int, siginfo_t   *, ucontext_t *));
-STATIC_PROTO (void HandleSIGUSER,  (int, siginfo_t   *, ucontext_t *));
 STATIC_PROTO (void my_signal_info, (int, void (*)(int, siginfo_t  *, ucontext_t *)));
 STATIC_PROTO (void my_signal, (int, void (*)(int, siginfo_t  *, ucontext_t *)));
 
@@ -906,7 +905,6 @@ my_signal(int sig, void (*handler)(int, siginfo_t *, ucontext_t *))
 
 STATIC_PROTO (RETSIGTYPE HandleMatherr, (int));
 STATIC_PROTO (RETSIGTYPE HandleSIGSEGV, (int));
-STATIC_PROTO (RETSIGTYPE HandleSIGUSER, (int));
 STATIC_PROTO (void my_signal_info, (int, void (*)(int)));
 STATIC_PROTO (void my_signal, (int, void (*)(int)));
 
@@ -1011,7 +1009,7 @@ HandleSIGSEGV(int   sig)
   SearchForTrailFault();
 }
 
-#ifdef HAVE_SIGACTION
+#if HAVE_SIGACTION
 
 static void
 my_signal_info(int sig, void (*handler)(int))
@@ -1253,40 +1251,10 @@ HandleALRM(int s)
 }
 #endif
 
-#if USE_SIGACTION
-/* this routine is called if YAP received one of the signals that
-   can be handled by user code, currently SIGUSR1 and SIGUSR2 */
-static RETSIGTYPE
-#if (defined(__svr4__) || defined(__SVR4))
-HandleSIGUSER (int s, siginfo_t   *x, ucontext_t *y)
-#else
-HandleSIGUSER(int s)
-#endif
-{
-  /* force the system to creep */
-  p_creep ();
-  /* raise the '$sig_pending' flag */
-  /* NOTE: shouldn't this be a queue? */
-  switch (s) {
-  case SIGUSR1:
-    PutValue(AtomSigPending, MkAtomTerm(LookupAtom("sig_usr1")));
-    break;
-  case SIGUSR2:
-    PutValue(AtomSigPending, MkAtomTerm(LookupAtom("sig_usr2")));
-    break;
-  default:
-    /* should never be here, freak out and die! */
-    /* YapErrorWhatever(); */
-    ;
-  }
-}
-#endif /* USE_SIGACTION */
-
-
 
 /*
- * This function is called after a normal interrupt had been caught It allows
+ * This function is called after a normal interrupt had been caught.
- * 6 possibilities : abort, continue, trace, debug, help, exit
+ * It allows 6 possibilities: abort, continue, trace, debug, help, exit.
  */
 
 #if !defined(LIGHT) && !_MSC_VER && !defined(__MINGW32__) && !defined(LIGHT) 
@@ -1311,9 +1279,30 @@ ReceiveSignal (int s)
     case SIGKILL:
       exit_yap (SIGKILL, "\n\n\n[ Quit signal received ]\n\n");
 #endif
+    case SIGUSR1:
+      /* force the system to creep */
+      p_creep ();
+      /* raise the '$sig_pending' flag */
+      /* NOTE: shouldn't this be a queue? */
+      PutValue(AtomSigPending, MkAtomTerm(LookupAtom("sig_usr1")));
+      break;
+    case SIGUSR2:
+      /* force the system to creep */
+      p_creep ();
+      /* raise the '$sig_pending' flag */
+      /* NOTE: shouldn't this be a queue? */
+      PutValue(AtomSigPending, MkAtomTerm(LookupAtom("sig_usr2")));
+      break;
+    case SIGHUP:
+      /* force the system to creep */
+      p_creep ();
+      /* raise the '$sig_pending' flag */
+      /* NOTE: shouldn't this be a queue? */
+      PutValue(AtomSigPending, MkAtomTerm(LookupAtom("sig_hup")));
+      break;
     default:
       YP_fprintf(YP_stderr, "\n[ Unexpected signal ]\n");
-      exit (FALSE);
+      exit (EXIT_FAILURE);
     }
 }
 #endif
@@ -1340,6 +1329,9 @@ InitSignals (void)
 #if !defined(LIGHT) && !_MSC_VER && !defined(__MINGW32__) && !defined(LIGHT) 
   my_signal (SIGQUIT, ReceiveSignal);
   my_signal (SIGKILL, ReceiveSignal);
+  my_signal (SIGUSR1, ReceiveSignal);
+  my_signal (SIGUSR2, ReceiveSignal);
+  my_signal (SIGHUP, ReceiveSignal);
   my_signal (SIGALRM, HandleALRM);
 #endif
 #if _MSC_VER || defined(__MINGW32__)
@@ -1348,10 +1340,6 @@ InitSignals (void)
 #else
   my_signal (SIGINT, HandleSIGINT);
 #endif
-#if USE_SIGACTION
-  my_signal (SIGUSR1, HandleSIGUSER);
-  my_signal (SIGUSR2, HandleSIGUSER);
-#endif
 #ifndef MPW
   my_signal (SIGFPE, HandleMatherr);
 #endif

H/Heap.h

@@ -10,7 +10,7 @@
 * File:		Heap.h         						 *
 * mods:									 *
 * comments:	Heap Init Structure					 *
-* version:      $Id: Heap.h,v 1.18 2002-01-09 17:19:36 stasinos Exp $	 *
+* version:      $Id: Heap.h,v 1.19 2002-01-11 15:54:17 stasinos Exp $	 *
 *************************************************************************/
 
 /* information that can be stored in Code Space */
@@ -196,7 +196,7 @@ typedef struct various_codes {
     atom_read,
     atom_repeat,
     atom_restore_regs,
-#if USE_SIGACTION
+#if HAVE_SIGACTION
     atom_sig_pending,
 #endif
     atom_stack_free,

config.h.in

@@ -201,8 +201,3 @@
 
 /* Is fflush(NULL) clobbering input streams? */
 #undef BROKEN_FFLUSH_NULL
-
-/* Should we do signal handling? */
-#if HAVE_SIGNAL_H && HAVE_SIGACTION
-#define USE_SIGACTION 1
-#endif

pl/boot.yap

@@ -32,6 +32,12 @@ true :- true. % otherwise, $$compile will ignore this clause.
 		),
 		'$system_catch'('$enter_top_level',Module,Error,user:'$Error'(Error)).
 
+read_sig :-
+	recorded('$sig_handler',X,_),
+	writeq(X),nl,
+	fail.
+read_sig.
+
 
 '$init_system' :-
 	(
@@ -40,6 +46,27 @@ true :- true. % otherwise, $$compile will ignore this clause.
 	;
 	  true
 	),
+	% If this is not here, the following get written twice in the idb. Why?
+	eraseall('$sig_handler'),
+	% The default interrupt handlers are kept, so that it's
+	% possible to revert to them with on_signal(S,_,default)
+	'$recordz'('$sig_handler',default(sig_hup,
+		         (( exists('~/.yaprc') -> [-'~/.yaprc'] ; true ),
+			  ( exists('~/.prologrc') -> [-'~/.prologrc'] ; true ),
+			  ( exists('~/prolog.ini') -> [-'~/prolog.ini'] ; true ))), _),
+	'$recordz'('$sig_handler',default(sig_usr1,
+		       (nl,writeq('[ Received user signal 1 ]'),nl,halt)), _),
+	'$recordz'('$sig_handler',default(sig_usr2,
+		       (nl,writeq('[ Received user signal 2 ]'),nl,halt)), _),
+	% The current interrupt handlers are also set the default values
+	'$recordz'('$sig_handler',action(sig_hup,
+		         (( exists('~/.yaprc') -> [-'~/.yaprc'] ; true ),
+			  ( exists('~/.prologrc') -> [-'~/.prologrc'] ; true ),
+			  ( exists('~/prolog.ini') -> [-'~/prolog.ini'] ; true ))), _),
+	'$recordz'('$sig_handler',action(sig_usr1,
+		       (nl,writeq('[ Received user signal 1 ]'),nl,halt)), _),
+	'$recordz'('$sig_handler',action(sig_usr2,
+		       (nl,writeq('[ Received user signal 2 ]'),nl,halt)), _),
 	'$set_yap_flags'(10,0),
 	'$set_value'('$gc',on),
 	'$init_catch',
@@ -67,6 +94,7 @@ true :- true. % otherwise, $$compile will ignore this clause.
 	    true
 	).
 
+
 %
 % encapsulate $cut_by because of co-routining.
 %
@@ -94,17 +122,6 @@ true :- true. % otherwise, $$compile will ignore this clause.
 '$enter_top_level' :-
         '$alarm'(0, _),
 	fail.
-% set the default user signal handlers
-'$enter_top_level' :-
-	( '$recorded'('$sig_handler',_,_) ->
-	    true
-	;
-	    '$recordz'('$sig_handler',
-		   action(sig_usr1,(format('Received user signal 1~n',[]),halt)), _),
-	    '$recordz'('$sig_handler',
-		   action(sig_usr2,(format('Received user signal 2~n',[]),halt)), _)
-	),
-	fail.
 '$enter_top_level' :-
 	'$clean_up_dead_clauses',
 	fail.

pl/debug.yap

@@ -720,8 +720,10 @@ debugging :-
 	),
 	'$execute'(M:Goal).
 '$creep'(G) :-
+	format( 'creeping...~n', [] ),
 	'$get_value'('$sig_pending', Signal),
-	\+ Signal = [], !,
+	format( 'Signal == ~q~n', [Signal] ),
+	Signal \== [], !,
 	'$set_value'('$sig_pending', []),
 	( '$recorded'('$sig_handler', action(Signal,A),_) ->
 	    '$execute'(A),

pl/utils.yap

@@ -231,11 +231,14 @@ alarm(Interval, Goal, Left) :-
 	'$recordz'('$alarm_handler',M:Goal,_),
 	'$alarm'(Interval, Left).
 
+on_signal(Signal,OldAction,default) :-
+	recorded('$sig_handler', default(Signal,Action), Ref),
+	on_signal(Signal,OldAction,Action).
 on_signal(Signal,OldAction,Action) :-
 	recorded('$sig_handler', action(Signal,OldAction), Ref),
 	erase(Ref),
 	'$current_module'(M),
-	'$recordz'('$sig_handler', action(Signal,M:Action),Ref2).
+	'$recordz'('$sig_handler', action(Signal,M:Action), _).
 
 
 %%% Saving and restoring a computation