From fea25712ca54c4715f874cf3d871e84bbfd83352 Mon Sep 17 00:00:00 2001
From: Michael Hendricks <michael@ndrix.org>
Date: Fri, 2 Mar 2012 12:24:38 -0700
Subject: [PATCH] Serialize access to debug.log stream

Acquire an exclusive, advisory lock before sending output to debug.log
and release it when we're done. This should avoid output from multiple
threads being interspersed in the log file.

We can't use CRITICAL_SECTION machinery for this because the debug log
is written during startup and shutdown when that machinery is not
available.

(Thanks to Gavin for pointing out the CRITICAL_SECTION problems based
on his earlier work in this area)
---
 src/util.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/util.cpp b/src/util.cpp
index b0c80f6df..d143306ae 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -25,6 +25,7 @@ namespace boost {
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
 #include <boost/foreach.hpp>
+#include <boost/thread.hpp>
 #include <openssl/crypto.h>
 #include <openssl/rand.h>
 #include <stdarg.h>
@@ -209,6 +210,8 @@ inline int OutputDebugStringF(const char* pszFormat, ...)
         if (fileout)
         {
             static bool fStartedNewLine = true;
+            static boost::mutex mutexDebugLog;
+            boost::mutex::scoped_lock scoped_lock(mutexDebugLog);
 
             // Debug print useful for profiling
             if (fLogTimestamps && fStartedNewLine)