[libxml2] xmlMemUsed is not thread-safe

[Daniel Veillard <veillard src gnome org>]

commit 8985cde70901c62d3f0f04da225e73b7344a52d7
Author: Martin von Gagern <Martin vGagern gmx net>
Date:   Mon Apr 13 16:32:14 2015 +0800

    xmlMemUsed is not thread-safe
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=747437
    just use the mutex to protect access to those variables

 xmlmemory.c |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/xmlmemory.c b/xmlmemory.c
index a3dc737..f24fd6d 100644
--- a/xmlmemory.c
+++ b/xmlmemory.c
@@ -554,7 +554,12 @@ xmlMemoryStrdup(const char *str) {
 
 int
 xmlMemUsed(void) {
-     return(debugMemSize);
+    int res;
+
+    xmlMutexLock(xmlMemMutex);
+    res = debugMemSize;
+    xmlMutexUnlock(xmlMemMutex);
+    return(res);
 }
 
 /**
@@ -567,7 +572,12 @@ xmlMemUsed(void) {
 
 int
 xmlMemBlocks(void) {
-     return(debugMemBlocks);
+    int res;
+
+    xmlMutexLock(xmlMemMutex);
+    res = debugMemBlocks;
+    xmlMutexUnlock(xmlMemMutex);
+    return(res);
 }
 
 #ifdef MEM_LIST