added debug support class

1 files changed, 133 insertions, 0 deletions

diff --git a/debug.c b/debug.c
new file mode 100644
index 00000000..b348476d
--- /dev/null
+++ b/debug.c
@@ -0,0 +1,133 @@
+/* debug.c
+ *
+ * This file proides debug and run time error analysis support. Some of the
+ * settings are very performance intense and my be turned off during a release
+ * build.
+ * 
+ * File begun on 2008-01-22 by RGerhards
+ *
+ * There is some in-depth documentation available in doc/dev_queue.html
+ * (and in the web doc set on http://www.rsyslog.com/doc). Be sure to read it
+ * if you are getting aquainted to the object.
+ *
+ * Copyright 2008 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of rsyslog.
+ *
+ * Rsyslog is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Rsyslog is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+
+
+#include "config.h" /* autotools! */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include <pthread.h>
+
+#include "rsyslog.h"
+#include "debug.h"
+
+/* static data (some time to be replaced) */
+int	Debug;		/* debug flag  - read-only after startup */
+int debugging_on = 0;	 /* read-only, except on sig USR1 */
+
+/* handler for SIGSEGV - MUST terminiate the app, but does so in a somewhat 
+ * more meaningful way.
+ * rgerhards, 2008-01-22
+ */
+void
+sigsegvHdlr(int signum)
+{
+	struct sigaction sigAct;
+	char *signame;
+
+	if(signum == SIGSEGV) {
+		signame = " (SIGSEGV)";
+	} else {
+		signame = "";
+	}
+
+	fprintf(stderr, "Signal %d%s occured, execution must be terminated %d.\n", signum, signame, SIGSEGV);
+	fflush(stderr);
+
+	/* re-instantiate original handler ... */
+	memset(&sigAct, 0, sizeof (sigAct));
+	sigemptyset(&sigAct.sa_mask);
+	sigAct.sa_handler = SIG_DFL;
+	sigaction(SIGSEGV, &sigAct, NULL);
+
+	/* and call it */
+	int i= raise(signum);
+	printf("raise returns %d, errno %d: %s\n", i, errno, strerror(errno));
+
+	/* we should never arrive here - but we provide some code just in case... */
+	fprintf(stderr, "sigsegvHdlr: oops, returned from raise(), doing exit(), something really wrong...\n");
+	exit(1);
+}
+
+
+/* print some debug output */
+void
+dbgprintf(char *fmt, ...)
+{
+	static pthread_t ptLastThrdID = 0;
+	static int bWasNL = 0;
+	va_list ap;
+
+	if ( !(Debug && debugging_on) )
+		return;
+	
+	/* The bWasNL handler does not really work. It works if no thread
+	 * switching occurs during non-NL messages. Else, things are messed
+	 * up. Anyhow, it works well enough to provide useful help during
+	 * getting this up and running. It is questionable if the extra effort
+	 * is worth fixing it, giving the limited appliability.
+	 * rgerhards, 2005-10-25
+	 * I have decided that it is not worth fixing it - especially as it works
+	 * pretty well.
+	 * rgerhards, 2007-06-15
+	 */
+	if(ptLastThrdID != pthread_self()) {
+		if(!bWasNL) {
+			fprintf(stdout, "\n");
+			bWasNL = 1;
+		}
+		ptLastThrdID = pthread_self();
+	}
+
+	if(bWasNL) {
+		fprintf(stdout, "%8.8x: ", (unsigned int) pthread_self());
+		//fprintf(stderr, "%8.8x: ", (unsigned int) pthread_self());
+	}
+	bWasNL = (*(fmt + strlen(fmt) - 1) == '\n') ? 1 : 0;
+	va_start(ap, fmt);
+	vfprintf(stdout, fmt, ap);
+	//vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	//fflush(stderr);
+	fflush(stdout);
+	return;
+}
+
+/* */
+
+/*
+ * vi:set ai:
+ */