Merge pull request #255 from dmitttri/fix-filecache-concurrent-access

fix: file cache operations concurrent access ensured with a mutex
xibosignage · Mar 26, 2022 · eaa6747 · eaa6747
2 parents 1fdfaac + b20f806
commit eaa6747
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diff --git a/player/common/storage/FileCacheImpl.cpp b/player/common/storage/FileCacheImpl.cpp
@@ -145,9 +145,12 @@ void FileCacheImpl::addToCache(const std::string& filename, const Md5Hash& hash,
     node.put(Md5Attr, hash);
     node.put(ValidAttr, hash == target);
 
+    /* critical section, access and modify file cache buffer */
+    fileCacheMutex_.lock();
     fileCache_.put_child(fullPath(filename), node);
 
     saveFileHashes(cacheFile_);
+    fileCacheMutex_.unlock();
 }
 
 void FileCacheImpl::addToCache(const std::string& filename, const Md5Hash& hash, const DateTime& lastUpdate)
@@ -157,9 +160,12 @@ void FileCacheImpl::addToCache(const std::string& filename, const Md5Hash& hash,
     node.put(LastUpdateAttr, lastUpdate.timestamp());
     node.put(ValidAttr, true);
 
+    /* critical section, access and modify file cache buffer */
+    fileCacheMutex_.lock();
     fileCache_.put_child(fullPath(filename), node);
 
     saveFileHashes(cacheFile_);
+    fileCacheMutex_.unlock();
 }
 
 void FileCacheImpl::loadFileHashes(const FilePath& path)

diff --git a/player/common/storage/FileCacheImpl.hpp b/player/common/storage/FileCacheImpl.hpp
@@ -4,6 +4,7 @@
 #include "common/storage/FileCache.hpp"
 
 #include <boost/noncopyable.hpp>
+#include <boost/thread/mutex.hpp>
 
 class FileCacheImpl : public FileCache, public XmlDefaultFileHandler, private boost::noncopyable
 {
@@ -31,6 +32,7 @@ class FileCacheImpl : public FileCache, public XmlDefaultFileHandler, private bo
     void saveFileHashes(const FilePath& path);
 
 private:
+    boost::mutex fileCacheMutex_;
     XmlNode fileCache_;
     FilePath cacheFile_;
 };