From ac15ce2da84080df06d26556c641c85bca02385f Mon Sep 17 00:00:00 2001
From: Armin Novak <armin.novak@thincast.com>
Date: Tue, 28 Apr 2015 08:55:26 +0200
Subject: [PATCH] Added mutex debug flag.

When mutex debugging is enabled now a stack trace
is logged, if a mutex is locked on destruction.
---
 cmake/ConfigOptions.cmake    |  1 +
 config.h.in                  |  1 +
 winpr/libwinpr/synch/mutex.c | 28 ++++++++++++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/cmake/ConfigOptions.cmake b/cmake/ConfigOptions.cmake
index 282659e..b51a46b 100644
--- a/cmake/ConfigOptions.cmake
+++ b/cmake/ConfigOptions.cmake
@@ -115,6 +115,7 @@ option(WITH_DEBUG_SND "Print rdpsnd debug messages" ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_SVC "Print static virtual channel debug messages." ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_TRANSPORT "Print transport debug messages." ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_THREADS "Print thread debug messages, enables handle dump" ${DEFAULT_DEBUG_OPTION})
+option(WITH_DEBUG_MUTEX "Print mutex debug messages" ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_TIMEZONE "Print timezone debug messages." ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_WND "Print window order debug messages" ${DEFAULT_DEBUG_OPTION})
 option(WITH_DEBUG_X11_CLIPRDR "Print X11 clipboard redirection debug messages" ${DEFAULT_DEBUG_OPTION})
diff --git a/config.h.in b/config.h.in
index 82c75ee..807148d 100644
--- a/config.h.in
+++ b/config.h.in
@@ -88,6 +88,7 @@
 #cmakedefine WITH_DEBUG_RDPEI
 #cmakedefine WITH_DEBUG_TIMEZONE
 #cmakedefine WITH_DEBUG_THREADS
+#cmakedefine WITH_DEBUG_MUTEX
 #cmakedefine WITH_DEBUG_TRANSPORT
 #cmakedefine WITH_DEBUG_WND
 #cmakedefine WITH_DEBUG_X11
diff --git a/winpr/libwinpr/synch/mutex.c b/winpr/libwinpr/synch/mutex.c
index 50d9508..37c54ba 100644
--- a/winpr/libwinpr/synch/mutex.c
+++ b/winpr/libwinpr/synch/mutex.c
@@ -22,12 +22,18 @@
 #endif
 
 #include <winpr/synch.h>
+#include <winpr/debug.h>
+#include <winpr/wlog.h>
 
 #include "synch.h"
 
 #ifndef _WIN32
 
 #include "../handle/handle.h"
+
+#include "../log.h"
+#define TAG WINPR_TAG("sync.mutex")
+
 static BOOL MutexCloseHandle(HANDLE handle);
 
 static BOOL MutexIsHandled(HANDLE handle)
@@ -61,6 +67,28 @@ BOOL MutexCloseHandle(HANDLE handle)
 	if (!MutexIsHandled(handle))
 		return FALSE;
 
+#if defined(WITH_DEBUG_MUTEX)
+	if (pthread_mutex_trylock(&mutex->mutex))
+	{
+		size_t used = 0, i;
+		void* stack = winpr_backtrace(20);
+		char **msg = NULL;
+
+		if (stack)
+			msg = winpr_backtrace_symbols(stack, &used);
+
+		if (msg)
+		{
+			for(i=0; i<used; i++)
+				WLog_ERR(TAG, "%2d: %s", i, msg[i]);
+		}
+		free (msg);
+		winpr_backtrace_free(stack);
+	}
+	else
+		pthread_mutex_unlock(&mutex->mutex);
+#endif
+
 	if (!pthread_mutex_destroy(&mutex->mutex))
 		return FALSE;
 
-- 
2.7.4