[Mono-dev] [RFC v3 05/10] Handle lack of SA_SIGINFO

Andreas Färber andreas.faerber at web.de
Mon Mar 29 18:56:13 EDT 2010


SA_SIGINFO-style signals are part of the optional POSIX XSI (formerly
Real Time Signals, RTS) feature. Haiku does not implement it (yet) and
goes so far as to not define SA_SIGINFO to indicate lack thereof.

In mini, there's MONO_ARCH_USE_SIGACTION for this but it doesn't cover
all uses of SA_SIGINFO; deal with the theoretical case of SA_SIGINFO being
defined but MONO_ARCH_USE_SIGACTION undefined.

Fix typo in comment.

v2 -> v3:
* Rework signature macros to match mini.

v1 -> v2:
* Introduce helper macros, suggested by Paolo Molaro.

This commit is licensed under the MIT X11 license.
---
 mono/metadata/ChangeLog      |    9 ++++++++-
 mono/metadata/console-unix.c |   36 ++++++++++++++++++++++++++----------
 mono/mini/ChangeLog          |    6 ++++++
 mono/mini/mini-posix.c       |   15 +++++++++++++--
 4 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/mono/metadata/ChangeLog b/mono/metadata/ChangeLog
index acc91c6..daf0ad1 100644
--- a/mono/metadata/ChangeLog
+++ b/mono/metadata/ChangeLog
@@ -1,3 +1,10 @@
+2010-03-29  Andreas Färber  <andreas.faerber at web.de>
+
+	* console-unix.c (sigcont_handler, sigwinch_handler): Don't assume
+	SA_SIGINFO-style signals, fix the build on platforms without (Haiku).
+
+	Code is contributed under MIT/X11 license.
+
 2010-03-29  Mark Probst  <mark.probst at gmail.com>
 
 	* sgen-gc.c: Use the same heuristic for the LOS target that we use
@@ -84,7 +91,7 @@ Fri Mar 26 19:03:09 CET 2010 Paolo Molaro <lupus at ximian.com>
 	when not needed and it allows keeping track of oldspace->nursery
 	references for the card table code.
 
-2010-03-26  Andreas Färber  <andreas.faerber at web.de>
+2010-03-26  Andreas Färber  <andreas.faerber at web.de>
 
 	* null-gc.c (mono_gc_invoke_with_gc_lock): Fix function name.
 
diff --git a/mono/metadata/console-unix.c b/mono/metadata/console-unix.c
index 99e0754..7280b6f 100644
--- a/mono/metadata/console-unix.c
+++ b/mono/metadata/console-unix.c
@@ -262,10 +262,32 @@ sigint_handler (int signo)
 	in_sigint = FALSE;
 }
 
+#define SIGHANDLER_VALID(sigh) \
+	((sigh) != NULL && \
+	 (sigh) != (void *)SIG_DFL && \
+	 (sigh) != (void *)SIG_IGN)
+
+#ifdef SA_SIGINFO
+#define SIG_HANDLER_SIGNATURE(ftn) ftn (int signo, void *the_siginfo, void *data)
+#define INVOKE_SIGHANDLER_IF_VALID(siga) G_STMT_START \
+		if ((siga).sa_flags & SA_SIGINFO) { \
+			if (SIGHANDLER_VALID((siga).sa_sigaction)) \
+				(*(siga).sa_sigaction) (signo, the_siginfo, data); \
+		} else if (SIGHANDLER_VALID((siga).sa_handler)) \
+			(*(siga).sa_handler) (signo); \
+	G_STMT_END
+#else
+#define SIG_HANDLER_SIGNATURE(ftn) ftn (int signo)
+#define INVOKE_SIGHANDLER_IF_VALID(siga) G_STMT_START \
+		if (SIGHANDLER_VALID((siga).sa_handler)) \
+			(*(siga).sa_handler) (signo); \
+	G_STMT_END
+#endif
+
 static struct sigaction save_sigcont, save_sigint, save_sigwinch;
 
 static void
-sigcont_handler (int signo, void *the_siginfo, void *data)
+SIG_HANDLER_SIGNATURE (sigcont_handler)
 {
 	// Ignore error, there is not much we can do in the sigcont handler.
 	tcsetattr (STDIN_FILENO, TCSANOW, &mono_attr);
@@ -274,24 +296,18 @@ sigcont_handler (int signo, void *the_siginfo, void *data)
 		write (STDOUT_FILENO, keypad_xmit_str, strlen (keypad_xmit_str));
 
 	// Call previous handler
-	if (save_sigcont.sa_sigaction != NULL &&
-	    save_sigcont.sa_sigaction != (void *)SIG_DFL &&
-	    save_sigcont.sa_sigaction != (void *)SIG_IGN)
-		(*save_sigcont.sa_sigaction) (signo, the_siginfo, data);
+	INVOKE_SIGHANDLER_IF_VALID (save_sigcont);
 }
 
 static void
-sigwinch_handler (int signo, void *the_siginfo, void *data)
+SIG_HANDLER_SIGNATURE (sigwinch_handler)
 {
 	int dims = terminal_get_dimensions ();
 	if (dims != -1)
 		cols_and_lines = dims;
 	
 	// Call previous handler
-	if (save_sigwinch.sa_sigaction != NULL &&
-	    save_sigwinch.sa_sigaction != (void *)SIG_DFL &&
-	    save_sigwinch.sa_sigaction != (void *)SIG_IGN)
-		(*save_sigwinch.sa_sigaction) (signo, the_siginfo, data);
+	INVOKE_SIGHANDLER_IF_VALID (save_sigwinch);
 }
 
 void
diff --git a/mono/mini/ChangeLog b/mono/mini/ChangeLog
index 1719b88..6794ddb 100755
--- a/mono/mini/ChangeLog
+++ b/mono/mini/ChangeLog
@@ -18,6 +18,12 @@
 
 2010-03-26  Andreas Faerber  <andreas.faerber at web.de>
 
+	* mini-posix.c: Fix the build on platforms without SA_SIGINFO (Haiku).
+
+	Code is contributed under MIT/X11 license.
+
+2010-03-26  Andreas Faerber  <andreas.faerber at web.de>
+
 	* mini-x86.c (mono_arch_is_single_step_event,
 	mono_arch_is_breakpoint_event): New define HAVE_SIG_INFO,
 	restrict it to MONO_ARCH_USE_SIGACTION to fix build on Haiku.
diff --git a/mono/mini/mini-posix.c b/mono/mini/mini-posix.c
index 1f04411..6c700d2 100644
--- a/mono/mini/mini-posix.c
+++ b/mono/mini/mini-posix.c
@@ -82,13 +82,17 @@ save_old_signal_handler (int signo, struct sigaction *old_action)
 	mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
 				"Saving old signal handler for signal %d.", signo);
 
+#ifdef SA_SIGINFO
 	if (! (old_action->sa_flags & SA_SIGINFO)) {
+#endif
 		handler_to_save->sa_handler = old_action->sa_handler;
+#ifdef SA_SIGINFO
 	} else {
 #ifdef MONO_ARCH_USE_SIGACTION
 		handler_to_save->sa_sigaction = old_action->sa_sigaction;
 #endif /* MONO_ARCH_USE_SIGACTION */
 	}
+#endif
 	handler_to_save->sa_mask = old_action->sa_mask;
 	handler_to_save->sa_flags = old_action->sa_flags;
 	
@@ -129,13 +133,17 @@ SIG_HANDLER_SIGNATURE (mono_chain_signal)
 	GET_CONTEXT;
 
 	if (saved_handler) {
+#ifdef SA_SIGINFO
 		if (!(saved_handler->sa_flags & SA_SIGINFO)) {
+#endif
 			saved_handler->sa_handler (signal);
+#ifdef SA_SIGINFO
 		} else {
 #ifdef MONO_ARCH_USE_SIGACTION
 			saved_handler->sa_sigaction (signal, info, ctx);
 #endif /* MONO_ARCH_USE_SIGACTION */
 		}
+#endif
 		return TRUE;
 	}
 	return FALSE;
@@ -387,9 +395,12 @@ add_signal_handler (int signo, gpointer handler)
 	g_assert (sigaction (signo, &sa, &previous_sa) != -1);
 
 	/* if there was already a handler in place for this signal, store it */
-	if (! (previous_sa.sa_flags & SA_SIGINFO) &&
+	if (
+#ifdef SA_SIGINFO
+		! (previous_sa.sa_flags & SA_SIGINFO) &&
+#endif
 			(SIG_DFL == previous_sa.sa_handler)) { 
-		/* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
+		/* if there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
 	} else {
 		if (mono_do_signal_chaining)
 			save_old_signal_handler (signo, &previous_sa);
-- 
1.7.0.3



More information about the Mono-devel-list mailing list