code review 3749041: os/signal: selective signal handling

src/pkg/runtime/signal_freebsd_386.c

Index: src/pkg/runtime/signal_freebsd_386.c
===================================================================
--- a/src/pkg/runtime/signal_freebsd_386.c
+++ b/src/pkg/runtime/signal_freebsd_386.c
@@ -50,6 +50,7 @@
 	Ucontext *uc;
 	Mcontext *r;
 	uintptr *sp;
+	SigTab *t;
 
 	uc = context;
 	r = &uc->uc_mcontext;
@@ -59,7 +60,10 @@
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -84,12 +88,15 @@
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -111,13 +118,6 @@
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -129,8 +129,8 @@
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -144,50 +144,3 @@
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}