Import BSDDB 4.7.25 (as of svn r89086)

common/util_sig.c

@@ -0,0 +1,110 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2000,2008 Oracle.  All rights reserved.
+ *
+ * $Id: util_sig.c 63573 2008-05-23 21:43:21Z trent.nelson $
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+
+static int	interrupt;
+static void	set_signal __P((int, int));
+static void	signal_handler __P((int));
+
+/*
+ * signal_handler --
+ *	Interrupt signal handler.
+ */
+static void
+signal_handler(signo)
+	int signo;
+{
+#ifndef HAVE_SIGACTION
+	/* Assume signal() is unreliable and reset it, first thing. */
+	set_signal(signo, 0);
+#endif
+	/* Some systems don't pass in the correct signal value -- check. */
+	if ((interrupt = signo) == 0)
+		interrupt = SIGINT;
+}
+
+/*
+ * set_signal
+ */
+static void
+set_signal(s, is_dflt)
+	int s, is_dflt;
+{
+	/*
+	 * Use sigaction if it's available, otherwise use signal().
+	 */
+#ifdef HAVE_SIGACTION
+	struct sigaction sa, osa;
+
+	sa.sa_handler = is_dflt ? SIG_DFL : signal_handler;
+	(void)sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;
+	(void)sigaction(s, &sa, &osa);
+#else
+	(void)signal(s, is_dflt ? SIG_DFL : signal_handler);
+#endif
+}
+
+/*
+ * __db_util_siginit --
+ *
+ * PUBLIC: void __db_util_siginit __P((void));
+ */
+void
+__db_util_siginit()
+{
+	/*
+	 * Initialize the set of signals for which we want to clean up.
+	 * Generally, we try not to leave the shared regions locked if
+	 * we can.
+	 */
+#ifdef SIGHUP
+	set_signal(SIGHUP, 0);
+#endif
+#ifdef SIGINT
+	set_signal(SIGINT, 0);
+#endif
+#ifdef SIGPIPE
+	set_signal(SIGPIPE, 0);
+#endif
+#ifdef SIGTERM
+	set_signal(SIGTERM, 0);
+#endif
+}
+
+/*
+ * __db_util_interrupted --
+ *	Return if interrupted.
+ *
+ * PUBLIC: int __db_util_interrupted __P((void));
+ */
+int
+__db_util_interrupted()
+{
+	return (interrupt != 0);
+}
+
+/*
+ * __db_util_sigresend --
+ *
+ * PUBLIC: void __db_util_sigresend __P((void));
+ */
+void
+__db_util_sigresend()
+{
+	/* Resend any caught signal. */
+	if (interrupt != 0) {
+		set_signal(interrupt, 1);
+
+		(void)raise(interrupt);
+		/* NOTREACHED */
+	}
+}