Merge pull request #2579 from akallabeth/mutex_debug_log

winpr mutex unlock on destroy

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})

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

winpr/libwinpr/synch/mutex.c

@@ -22,12 +22,20 @@
 #endif
 
 #include <winpr/synch.h>
+#include <winpr/debug.h>
+#include <winpr/wlog.h>
 
 #include "synch.h"
 
 #ifndef _WIN32
 
+#include <errno.h>
+
 #include "../handle/handle.h"
+
+#include "../log.h"
+#define TAG WINPR_TAG("sync.mutex")
+
 static BOOL MutexCloseHandle(HANDLE handle);
 
 static BOOL MutexIsHandled(HANDLE handle)
@@ -57,12 +65,54 @@ static int MutexGetFd(HANDLE handle)
 BOOL MutexCloseHandle(HANDLE handle)
 {
 	WINPR_MUTEX* mutex = (WINPR_MUTEX*) handle;
+	int rc;
 
 	if (!MutexIsHandled(handle))
 		return FALSE;
 
-	if (!pthread_mutex_destroy(&mutex->mutex))
+	rc = pthread_mutex_trylock(&mutex->mutex);
+	switch(rc)
+	{
+		/* If we already own the mutex consider it a success. */
+		case EDEADLK:
+		case EBUSY:
+			break;
+		default:
+#if defined(WITH_DEBUG_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);
+		}
+#endif
+		WLog_ERR(TAG, "pthread_mutex_trylock failed with %s [%d]", strerror(rc), rc);
 		return FALSE;
+	}
+
+	rc = pthread_mutex_unlock(&mutex->mutex);
+	if (rc != 0)
+	{
+		WLog_ERR(TAG, "pthread_mutex_unlock failed with %s [%d]", strerror(rc), rc);
+		return FALSE;
+	}
+
+	rc = pthread_mutex_destroy(&mutex->mutex);
+	if (rc != 0)
+	{
+		WLog_ERR(TAG, "pthread_mutex_destroy failed with %s [%d]", strerror(rc), rc);
+		return FALSE;
+	}
 
 	free(handle);