possibly fixed threading problems with chunk cache

chunkcache.cpp

@@ -52,7 +52,9 @@ ChunkCache::~ChunkCache()
 void ChunkCache::clear()
 {
 	QThreadPool::globalInstance()->waitForDone();
+	mutex.lock();
 	cache.clear();
+	mutex.unlock();
 }
 
 void ChunkCache::setPath(QString path)
@@ -67,7 +69,9 @@ QString ChunkCache::getPath()
 Chunk *ChunkCache::fetch(int x, int z)
 {
 	ChunkID id(x,z);
+	mutex.lock();
 	Chunk *chunk=cache[id];
+	mutex.unlock();
 	if (chunk!=NULL)
 	{
 		if (chunk->loaded)
@@ -76,8 +80,10 @@ Chunk *ChunkCache::fetch(int x, int z)
 	}
 	// launch background process to load this chunk
 	chunk=new Chunk();
+	mutex.lock();
 	cache.insert(id,chunk);
-	ChunkLoader *loader=new ChunkLoader(path,x,z,cache);
+	mutex.unlock();
+	ChunkLoader *loader=new ChunkLoader(path,x,z,cache,mutex);
 	connect(loader,SIGNAL(loaded(int,int)),
 			this,SLOT(gotChunk(int,int)));
 	QThreadPool::globalInstance()->start(loader);

chunkcache.h

@@ -64,6 +64,7 @@ private slots:
 private:
 	QString path;
 	QCache<ChunkID,Chunk> cache;
+	QMutex mutex;
 };
 
 #endif

chunkloader.cpp

@@ -29,7 +29,7 @@
 #include "chunkcache.h"
 #include "chunk.h"
 
-ChunkLoader::ChunkLoader(QString path,int x,int z,QCache<ChunkID,Chunk> &cache) : path(path),x(x),z(z),cache(cache)
+ChunkLoader::ChunkLoader(QString path,int x,int z,QCache<ChunkID,Chunk> &cache,QMutex &mutex) : path(path),x(x),z(z),cache(cache),mutex(mutex)
 {
 }
 ChunkLoader::~ChunkLoader()
@@ -64,9 +64,11 @@ void ChunkLoader::run()
 	uchar *raw=f.map(coffset*4096,numSectors*4096);
 	NBT nbt(raw);
 	ChunkID id(x,z);
+	mutex.lock();
 	Chunk *chunk=cache[id];
 	if (chunk)
 		chunk->load(nbt);
+	mutex.unlock();
 	f.unmap(raw);
 	f.close();
 

chunkloader.h

@@ -32,12 +32,13 @@
 #include <QRunnable>
 class Chunk;
 class ChunkID;
+class QMutex;
 
 class ChunkLoader : public QObject, public QRunnable
 {
 	Q_OBJECT
 public:
-	ChunkLoader(QString path,int x,int z,QCache<ChunkID,Chunk> &cache);
+	ChunkLoader(QString path,int x,int z,QCache<ChunkID,Chunk> &cache,QMutex &mutex);
 	~ChunkLoader();
 signals:
 	void loaded(int x,int z);
@@ -47,6 +48,7 @@ class ChunkLoader : public QObject, public QRunnable
 	QString path;
 	int x,z;
 	QCache<ChunkID,Chunk> &cache;
+	QMutex &mutex;
 };
 
 #endif

mapview.cpp

@@ -184,7 +184,16 @@ void MapView::paintEvent(QPaintEvent *)
 void MapView::redraw()
 {
 	if (!this->isEnabled())
+	{
+		// blank
+		uchar *bits=image.bits();
+		int imgstride=image.bytesPerLine();
+		int imgoffset=0;
+		for (int y=0;y<image.height();y++,imgoffset+=imgstride)
+			memset(bits+imgoffset,0xee,imgstride);
+		update();
 		return;
+	}
 
 	double chunksize=16*zoom;