Turned the loaded images map into a singleton.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34368 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/Shelf.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009, Haiku.
+ * Copyright 2001-2009, Haiku, Inc.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -12,6 +12,10 @@
 
 /*!	BShelf stores replicant views that are dropped onto it */
 
+#include <Shelf.h>
+
+#include <pthread.h>
+
 #include <AutoLock.h>
 #include <Beep.h>
 #include <Dragger.h>
@@ -24,7 +28,6 @@
 #include <Point.h>
 #include <PropertyInfo.h>
 #include <Rect.h>
-#include <Shelf.h>
 #include <String.h>
 #include <View.h>
 
@@ -39,9 +42,55 @@
 #include <utility>
 
 
+namespace {
+
 typedef std::map<BString, std::pair<image_id, int32> > LoadedImageMap;
-static LoadedImageMap	sLoadedImages;
+
-static BLocker			sLoadedImageMapLocker("BShelf loaded image map");
+struct LoadedImages {
+	LoadedImageMap			images;
+
+	LoadedImages()
+		:
+		fLock("BShelf loaded image map")
+	{
+	}
+
+	bool Lock()
+	{
+		return fLock.Lock();
+	}
+
+	void Unlock()
+	{
+		fLock.Unlock();
+	}
+
+	static LoadedImages* Default()
+	{
+		if (sDefaultInstance == NULL)
+			pthread_once(&sDefaultInitOnce, &_InitSingleton);
+
+		return sDefaultInstance;
+	}
+
+private:
+	static void _InitSingleton()
+	{
+		sDefaultInstance = new LoadedImages;
+	}
+
+private:
+	BLocker					fLock;
+
+	static pthread_once_t	sDefaultInitOnce;
+	static LoadedImages*	sDefaultInstance;
+};
+
+pthread_once_t LoadedImages::sDefaultInitOnce = PTHREAD_ONCE_INIT;
+LoadedImages* LoadedImages::sDefaultInstance = NULL;
+
+}	// unnamed namespace
+
 
 static property_info sShelfPropertyList[] = {
 	{
@@ -1167,15 +1216,17 @@ BShelf::_DeleteReplicant(replicant_data* item)
 	const char* signature = NULL;
 	if (item->message->FindString("add_on", &signature) == B_OK
 		&& signature != NULL) {
-		AutoLock<BLocker> lock(sLoadedImageMapLocker);
+		LoadedImages* loadedImages = LoadedImages::Default();
+		AutoLock<LoadedImages> lock(loadedImages);
 		if (lock.IsLocked()) {
-			LoadedImageMap::iterator it = sLoadedImages.find(BString(signature));
+			LoadedImageMap::iterator it = loadedImages->images.find(
+				BString(signature));
 
-			if (it != sLoadedImages.end()) {
+			if (it != loadedImages->images.end()) {
 				(*it).second.second--;
 				if ((*it).second.second <= 0) {
 					unload_add_on((*it).second.first);
-					sLoadedImages.erase(it);
+					loadedImages->images.erase(it);
 				}
 			}
 		}
@@ -1264,12 +1315,14 @@ BShelf::_AddReplicant(BMessage *data, BPoint *location, uint32 uniqueID)
 	// Update use count for image
 	const char* signature = NULL;
 	if (data->FindString("add_on", &signature) == B_OK && signature != NULL) {
-		AutoLock<BLocker> lock(sLoadedImageMapLocker);
+		LoadedImages* loadedImages = LoadedImages::Default();
+		AutoLock<LoadedImages> lock(loadedImages);
 		if (lock.IsLocked()) {
-			LoadedImageMap::iterator it = sLoadedImages.find(BString(signature));
+			LoadedImageMap::iterator it = loadedImages->images.find(
+				BString(signature));
 
-			if (it == sLoadedImages.end())
+			if (it == loadedImages->images.end())
-				sLoadedImages.insert(LoadedImageMap::value_type(
+				loadedImages->images.insert(LoadedImageMap::value_type(
 					BString(signature), std::pair<image_id, int>(image, 1)));
 			else
 				(*it).second.second++;