From: Georg Baum <baum@lyx.org>
Date: Sat, 5 Jul 2014 10:39:59 +0000 (+0200)
Subject: Make BufferParams::auto_packages() threadsafe
X-Git-Tag: 2.2.0alpha1~1791
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=e7c41b5f56e48670ed6415edac1811167a1e177b;p=features.git

Make BufferParams::auto_packages() threadsafe
---

diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index 49c55aaa51..792f14833f 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -52,6 +52,7 @@
 #include "support/filetools.h"
 #include "support/gettext.h"
 #include "support/Messages.h"
+#include "support/mutex.h"
 #include "support/Translator.h"
 #include "support/lstrings.h"
 
@@ -446,10 +447,16 @@ void BufferParams::use_package(std::string const & p, BufferParams::Package u)
 
 map<string, string> const & BufferParams::auto_packages()
 {
-	// FIXME THREAD
-	// It is extremely unlikely that there could be a problem here, but...
 	static map<string, string> packages;
 	if (packages.empty()) {
+		// We could have a race condition here that two threads
+		// discover an empty map at the same time and want to fill
+		// it, but that is no problem, since the same contents is
+		// filled in twice then. Having the locker inside the
+		// packages.empty() condition has the advantage that we
+		// don't need the mutex overhead for simple reading.
+		static Mutex mutex;
+		Mutex::Locker locker(&mutex);
 		// adding a package here implies a file format change!
 		packages["amsmath"] =
 			N_("The LaTeX package amsmath is only used if AMS formula types or symbols from the AMS math toolbars are inserted into formulas");