SIG_USR handling seems to be working

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@282 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

C/init.c

@@ -874,6 +874,9 @@ InitCodes(void)
   AtomArrow = LookupAtom("->");
   heap_regs->atom_assert = LookupAtom(":-");
   heap_regs->atom_alarm = LookupAtom("$alarm");
+#if USE_SIGACTION
+  heap_regs->atom_sig_pending = LookupAtom("$sig_pending");
+#endif
   AtomBraces = LookupAtom("{}");
   heap_regs->atom_b = LookupAtom("$last_choice_pt");
   heap_regs->atom_break = LookupAtom("$break");

C/save.c

@@ -1050,6 +1050,9 @@ 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
+  heap_regs->atom_sig_pending = AtomAdjust(heap_regs->atom_sig_pending);
+#endif
   heap_regs->atom_stack_free = AtomAdjust(heap_regs->atom_stack_free);
   heap_regs->atom_true = AtomAdjust(heap_regs->atom_true);
   heap_regs->atom_user = AtomAdjust(heap_regs->atom_user);

C/sysbits.c

@@ -823,6 +823,7 @@ 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 *)));
 
@@ -901,10 +902,11 @@ my_signal(int sig, void (*handler)(int, siginfo_t *, ucontext_t *))
   sigaction(sig,&sigact,NULL);
 }
 
-#else
+#else /* if not (defined(__svr4__) || defined(__SVR4)) */
 
 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)));
 
@@ -1051,7 +1053,7 @@ void (*handler)(int);
 }
 #endif /* __linux__ */
 
-#endif
+#endif /* (defined(__svr4__) || defined(__SVR4)) */
 
 
 static int
@@ -1251,6 +1253,37 @@ 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
  * 6 possibilities : abort, continue, trace, debug, help, exit
@@ -1315,6 +1348,10 @@ 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 1.17 2002-01-07 06:28:03 vsc Exp $	 *
+* version:      $Id: Heap.h,v 1.18 2002-01-09 17:19:36 stasinos Exp $	 *
 *************************************************************************/
 
 /* information that can be stored in Code Space */
@@ -196,6 +196,9 @@ typedef struct various_codes {
     atom_read,
     atom_repeat,
     atom_restore_regs,
+#if USE_SIGACTION
+    atom_sig_pending,
+#endif
     atom_stack_free,
     atom_true,
     atom_unwritable,
@@ -350,11 +353,9 @@ typedef struct various_codes {
 #define  AtomCsult                heap_regs->atom_csult
 #define  AtomCut                  heap_regs->atom_cut
 #define  AtomCutBy                heap_regs->atom_cut_by
-#ifdef EUROTRA
+#if defined(EUROTRA) && defined(SFUNC)
-#ifdef SFUNC
 #define  AtomDollarUndef          heap_regs->atom_dollar_undef
 #endif
-#endif
 #define  AtomE                    heap_regs->atom_e
 #define  AtomEQ                   heap_regs->atom_e_q
 #define  AtomEof                  heap_regs->atom_eof
@@ -387,6 +388,9 @@ typedef struct various_codes {
 #define  AtomRead                 heap_regs->atom_read
 #define  AtomRepeat               heap_regs->atom_repeat
 #define  AtomRestoreRegs          heap_regs->atom_restore_regs
+#if USE_SIGACTION
+#define  AtomSigPending           heap_regs->atom_sig_pending
+#endif
 #define  AtomStackFree            heap_regs->atom_stack_free
 #define  AtomTrue                 heap_regs->atom_true
 #define  AtomUser                 heap_regs->atom_user

config.h.in

@@ -199,4 +199,10 @@
 #define USE_GMP 1
 #endif
 
+/* 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

@@ -94,6 +94,17 @@ 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

@@ -739,6 +739,17 @@ debugging :-
 	    true
 	),
 	'$execute'(M:Goal).
+'$creep'(G) :-
+	'$get_value'('$sig_pending', Signal),
+	\+ Signal = [], !,
+	'$set_value'('$sig_pending', []),
+	( '$recorded'('$sig_handler', action(Signal,A),_) ->
+	    '$execute'(A),
+	    G=[M|Goal] 
+	;
+	    true
+	),
+	'$execute'(M:Goal).
 '$creep'(_) :-
 	'$get_value'('$throw', true), !,
 	'$set_value'('$throw', false),

pl/setof.yap

@@ -91,7 +91,7 @@ setof(Template, Generator, Set) :-
 % And this is bagof
 
 % Either we have excess of variables
-% and we need to find the solutions for each instantion
+% and we need to find the solutions for each instantiation
 % of these variables
 
 bagof(Template, Generator, Bag) :-

pl/utils.yap

@@ -231,6 +231,13 @@ alarm(Interval, Goal, Left) :-
 	'$recordz'('$alarm_handler',M:Goal,_),
 	'$alarm'(Interval, Left).
 
+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).
+
+
 %%% Saving and restoring a computation
 
 save(A) :- var(A), !,