From 975a848b6783091108c861ee1015cb89fc85f7fe Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Fri, 23 May 2008 22:35:50 +0000
Subject: A new feature thanks to the fine folks at Switchvox!

If a deadlock is detected, then the typical lock information will be
printed along with a backtrace of the stack for the offending threads.
Use of this requires compiling with DETECT_DEADLOCKS and having glibc
installed.

Furthermore, issuing the "core show locks" CLI command will print the
normal lock information as well as a backtraces for each lock. This
requires that DEBUG_THREADS is enabled and that glibc is installed.

All the backtrace features may be disabled by running the configure
script with --without-execinfo as an argument



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@118173 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/logger.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 51 insertions(+), 14 deletions(-)

(limited to 'main/logger.c')

diff --git a/main/logger.c b/main/logger.c
index a4936badd..d20ac8bc5 100644
--- a/main/logger.c
+++ b/main/logger.c
@@ -1127,30 +1127,67 @@ void ast_log(int level, const char *file, int line, const char *function, const
 	return;
 }
 
+#ifdef HAVE_BKTR
+
+struct ast_bt *ast_bt_create(void) 
+{
+	struct ast_bt *bt = ast_calloc(1, sizeof(*bt));
+	if (!bt) {
+		ast_log(LOG_ERROR, "Unable to allocate memory for backtrace structure!\n");
+		return NULL;
+	}
+
+	bt->alloced = 1;
+
+	ast_bt_get_addresses(bt);
+
+	return bt;
+}
+
+int ast_bt_get_addresses(struct ast_bt *bt)
+{
+	bt->num_frames = backtrace(bt->addresses, AST_MAX_BT_FRAMES);
+
+	return 0;
+}
+
+void *ast_bt_destroy(struct ast_bt *bt)
+{
+	if (bt->alloced) {
+		ast_free(bt);
+	}
+
+	return NULL;
+}
+
+#endif /* HAVE_BKTR */
+
 void ast_backtrace(void)
 {
 #ifdef HAVE_BKTR
-	int count = 0, i = 0;
-	void **addresses;
+	struct ast_bt *backtrace;
+	int i = 0;
 	char **strings;
 
-	if ((addresses = ast_calloc(MAX_BACKTRACE_FRAMES, sizeof(*addresses)))) {
-		count = backtrace(addresses, MAX_BACKTRACE_FRAMES);
-		if ((strings = backtrace_symbols(addresses, count))) {
-			ast_debug(1, "Got %d backtrace record%c\n", count, count != 1 ? 's' : ' ');
-			for (i = 0; i < count; i++) {
+	if (!(backtrace = ast_bt_create())) {
+		ast_log(LOG_WARNING, "Unable to allocate space for backtrace structure\n");
+		return;
+	}
+
+	if ((strings = backtrace_symbols(backtrace->addresses, backtrace->num_frames))) {
+		ast_debug(1, "Got %d backtrace record%c\n", backtrace->num_frames, backtrace->num_frames != 1 ? 's' : ' ');
+		for (i = 0; i < backtrace->num_frames; i++) {
 #if __WORDSIZE == 32
-				ast_log(LOG_DEBUG, "#%d: [%08X] %s\n", i, (unsigned int)addresses[i], strings[i]);
+			ast_log(LOG_DEBUG, "#%d: [%08X] %s\n", i, (unsigned int)backtrace->addresses[i], strings[i]);
 #elif __WORDSIZE == 64
-				ast_log(LOG_DEBUG, "#%d: [%016lX] %s\n", i, (unsigned long)addresses[i], strings[i]);
+			ast_log(LOG_DEBUG, "#%d: [%016lX] %s\n", i, (unsigned long)backtrace->addresses[i], strings[i]);
 #endif
-			}
-			free(strings);
-		} else {
-			ast_debug(1, "Could not allocate memory for backtrace\n");
 		}
-		ast_free(addresses);
+		free(strings);
+	} else {
+		ast_debug(1, "Could not allocate memory for backtrace\n");
 	}
+	ast_bt_destroy(backtrace);
 #else
 	ast_log(LOG_WARNING, "Must run configure with '--with-execinfo' for stack backtraces.\n");
 #endif
-- 
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