db/simple: use class ScopeDatabaseLock

src/db/plugins/simple/DatabaseSave.cxx

@@ -72,7 +72,6 @@ db_load_internal(TextFile &file, Directory &music_root, Error &error)
 	char *line;
 	unsigned format = 0;
 	bool found_charset = false, found_version = false;
-	bool success;
 	bool tags[TAG_NUM_OF_ITEM_TYPES];
 
 	/* get initial info */
@@ -152,9 +151,6 @@ db_load_internal(TextFile &file, Directory &music_root, Error &error)
 
 	LogDebug(db_domain, "reading DB");
 
-	db_lock();
-	success = directory_load(file, music_root, error);
-	db_unlock();
-
-	return success;
+	const ScopeDatabaseLock protect;
+	return directory_load(file, music_root, error);
 }

src/db/plugins/simple/SimpleDatabasePlugin.cxx

@@ -240,13 +240,13 @@ SimpleDatabase::GetSong(const char *uri, Error &error) const
 	assert(prefixed_light_song == nullptr);
 	assert(borrowed_song_count == 0);
 
-	db_lock();
+	ScopeDatabaseLock protect;
 
 	auto r = root->LookupDirectory(uri);
 
 	if (r.directory->IsMount()) {
 		/* pass the request to the mounted database */
-		db_unlock();
+		protect.unlock();
 
 		const LightSong *song =
 			r.directory->mounted_database->GetSong(r.uri, error);
@@ -260,7 +260,6 @@ SimpleDatabase::GetSong(const char *uri, Error &error) const
 
 	if (r.uri == nullptr) {
 		/* it's a directory */
-		db_unlock();
 		error.Format(db_domain, DB_NOT_FOUND,
 			     "No such song: %s", uri);
 		return nullptr;
@@ -268,14 +267,13 @@ SimpleDatabase::GetSong(const char *uri, Error &error) const
 
 	if (strchr(r.uri, '/') != nullptr) {
 		/* refers to a URI "below" the actual song */
-		db_unlock();
 		error.Format(db_domain, DB_NOT_FOUND,
 			     "No such song: %s", uri);
 		return nullptr;
 	}
 
 	const Song *song = r.directory->FindSong(r.uri);
-	db_unlock();
+	protect.unlock();
 	if (song == nullptr) {
 		error.Format(db_domain, DB_NOT_FOUND,
 			     "No such song: %s", uri);
@@ -367,15 +365,15 @@ SimpleDatabase::GetStats(const DatabaseSelection &selection,
 bool
 SimpleDatabase::Save(Error &error)
 {
-	db_lock();
-
-	LogDebug(simple_db_domain, "removing empty directories from DB");
-	root->PruneEmpty();
+	{
+		const ScopeDatabaseLock protect;
 
-	LogDebug(simple_db_domain, "sorting DB");
-	root->Sort();
+		LogDebug(simple_db_domain, "removing empty directories from DB");
+		root->PruneEmpty();
 
-	db_unlock();
+		LogDebug(simple_db_domain, "sorting DB");
+		root->Sort();
+	}
 
 	LogDebug(simple_db_domain, "writing DB");
 

src/db/update/Archive.cxx

@@ -39,6 +39,27 @@
 #include <sys/stat.h>
 #include <string.h>
 
+static Directory *
+LockFindChild(Directory &directory, const char *name)
+{
+	const ScopeDatabaseLock protect;
+	return directory.FindChild(name);
+}
+
+static Directory *
+LockMakeChild(Directory &directory, const char *name)
+{
+	const ScopeDatabaseLock protect;
+	return directory.MakeChild(name);
+}
+
+static Song *
+LockFindSong(Directory &directory, const char *name)
+{
+	const ScopeDatabaseLock protect;
+	return directory.FindSong(name);
+}
+
 void
 UpdateWalk::UpdateArchiveTree(Directory &directory, const char *name)
 {
@@ -46,11 +67,9 @@ UpdateWalk::UpdateArchiveTree(Directory &directory, const char *name)
 	if (tmp) {
 		const std::string child_name(name, tmp);
 		//add dir is not there already
-		db_lock();
-		Directory *subdir =
-			directory.MakeChild(child_name.c_str());
+		Directory *subdir = LockMakeChild(directory,
+						  child_name.c_str());
 		subdir->device = DEVICE_INARCHIVE;
-		db_unlock();
 
 		//create directories first
 		UpdateArchiveTree(*subdir, tmp + 1);
@@ -62,15 +81,14 @@ UpdateWalk::UpdateArchiveTree(Directory &directory, const char *name)
 		}
 
 		//add file
-		db_lock();
-		Song *song = directory.FindSong(name);
-		db_unlock();
+		Song *song = LockFindSong(directory, name);
 		if (song == nullptr) {
 			song = Song::LoadFile(storage, name, directory);
 			if (song != nullptr) {
-				db_lock();
-				directory.AddSong(song);
-				db_unlock();
+				{
+					const ScopeDatabaseLock protect;
+					directory.AddSong(song);
+				}
 
 				modified = true;
 				FormatDefault(update_domain, "added %s/%s",
@@ -108,9 +126,7 @@ UpdateWalk::UpdateArchiveFile(Directory &parent, const char *name,
 			      const StorageFileInfo &info,
 			      const ArchivePlugin &plugin)
 {
-	db_lock();
-	Directory *directory = parent.FindChild(name);
-	db_unlock();
+	Directory *directory = LockFindChild(parent, name);
 
 	if (directory != nullptr && directory->mtime == info.mtime &&
 	    !walk_discard)
@@ -139,12 +155,12 @@ UpdateWalk::UpdateArchiveFile(Directory &parent, const char *name,
 	if (directory == nullptr) {
 		FormatDebug(update_domain,
 			    "creating archive directory: %s", name);
-		db_lock();
+
+		const ScopeDatabaseLock protect;
 		directory = parent.CreateChild(name);
 		/* mark this directory as archive (we use device for
 		   this) */
 		directory->device = DEVICE_INARCHIVE;
-		db_unlock();
 	}
 
 	directory->mtime = info.mtime;

src/db/update/Container.cxx

@@ -78,16 +78,16 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 		return false;
 	const DecoderPlugin &plugin = *_plugin;
 
-	db_lock();
-	Directory *contdir = MakeDirectoryIfModified(directory, name, info);
-	if (contdir == nullptr) {
-		/* not modified */
-		db_unlock();
-		return true;
-	}
+	Directory *contdir;
+	{
+		const ScopeDatabaseLock protect;
+		contdir = MakeDirectoryIfModified(directory, name, info);
+		if (contdir == nullptr)
+			/* not modified */
+			return true;
 
-	contdir->device = DEVICE_CONTAINER;
-	db_unlock();
+		contdir->device = DEVICE_CONTAINER;
+	}
 
 	const auto pathname = storage.MapFS(contdir->GetPath());
 	if (pathname.IsNull()) {
@@ -116,9 +116,10 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 
 		tag_builder.Commit(song->tag);
 
-		db_lock();
-		contdir->AddSong(song);
-		db_unlock();
+		{
+			const ScopeDatabaseLock protect;
+			contdir->AddSong(song);
+		}
 
 		modified = true;
 

src/db/update/Editor.cxx

@@ -50,9 +50,8 @@ DatabaseEditor::DeleteSong(Directory &dir, Song *del)
 void
 DatabaseEditor::LockDeleteSong(Directory &parent, Song *song)
 {
-	db_lock();
+	const ScopeDatabaseLock protect;
 	DeleteSong(parent, song);
-	db_unlock();
 }
 
 /**
@@ -87,17 +86,17 @@ DatabaseEditor::DeleteDirectory(Directory *directory)
 void
 DatabaseEditor::LockDeleteDirectory(Directory *directory)
 {
-	db_lock();
+	const ScopeDatabaseLock protect;
 	DeleteDirectory(directory);
-	db_unlock();
 }
 
 bool
 DatabaseEditor::DeleteNameIn(Directory &parent, const char *name)
 {
+	const ScopeDatabaseLock protect;
+
 	bool modified = false;
 
-	db_lock();
 	Directory *directory = parent.FindChild(name);
 
 	if (directory != nullptr) {
@@ -113,7 +112,5 @@ DatabaseEditor::DeleteNameIn(Directory &parent, const char *name)
 
 	parent.playlists.erase(name);
 
-	db_unlock();
-
 	return modified;
 }

src/db/update/Service.cxx

@@ -80,9 +80,11 @@ UpdateService::CancelMount(const char *uri)
 	/* determine which (mounted) database will be updated and what
 	   storage will be scanned */
 
-	db_lock();
-	const auto lr = db.GetRoot().LookupDirectory(uri);
-	db_unlock();
+	Directory::LookupResult lr;
+	{
+		const ScopeDatabaseLock protect;
+		lr = db.GetRoot().LookupDirectory(uri);
+	}
 
 	if (!lr.directory->IsMount())
 		return;
@@ -188,9 +190,12 @@ UpdateService::Enqueue(const char *path, bool discard)
 	SimpleDatabase *db2;
 	Storage *storage2;
 
-	db_lock();
-	const auto lr = db.GetRoot().LookupDirectory(path);
-	db_unlock();
+	Directory::LookupResult lr;
+	{
+		const ScopeDatabaseLock protect;
+		lr = db.GetRoot().LookupDirectory(path);
+	}
+
 	if (lr.directory->IsMount()) {
 		/* follow the mountpoint, update the mounted
 		   database */

src/db/update/UpdateSong.cxx

@@ -35,9 +35,11 @@ UpdateWalk::UpdateSongFile2(Directory &directory,
 			    const char *name, const char *suffix,
 			    const StorageFileInfo &info)
 {
-	db_lock();
-	Song *song = directory.FindSong(name);
-	db_unlock();
+	Song *song;
+	{
+		const ScopeDatabaseLock protect;
+		song = directory.FindSong(name);
+	}
 
 	if (!directory_child_access(storage, directory, name, R_OK)) {
 		FormatError(update_domain,
@@ -69,9 +71,10 @@ UpdateWalk::UpdateSongFile2(Directory &directory,
 			return;
 		}
 
-		db_lock();
-		directory.AddSong(song);
-		db_unlock();
+		{
+			const ScopeDatabaseLock protect;
+			directory.AddSong(song);
+		}
 
 		modified = true;
 		FormatDefault(update_domain, "added %s/%s",

src/db/update/Walk.cxx

@@ -78,7 +78,7 @@ inline void
 UpdateWalk::RemoveExcludedFromDirectory(Directory &directory,
 					const ExcludeList &exclude_list)
 {
-	db_lock();
+	const ScopeDatabaseLock protect;
 
 	directory.ForEachChildSafe([&](Directory &child){
 			const auto name_fs =
@@ -99,8 +99,6 @@ UpdateWalk::RemoveExcludedFromDirectory(Directory &directory,
 				modified = true;
 			}
 		});
-
-	db_unlock();
 }
 
 inline void
@@ -129,9 +127,8 @@ UpdateWalk::PurgeDeletedFromDirectory(Directory &directory)
 	     i != end;) {
 		if (!directory_child_is_regular(storage, directory,
 						i->name.c_str())) {
-			db_lock();
+			const ScopeDatabaseLock protect;
 			i = directory.playlists.erase(i);
-			db_unlock();
 		} else
 			++i;
 	}
@@ -198,10 +195,9 @@ UpdateWalk::UpdatePlaylistFile(Directory &directory,
 
 	PlaylistInfo pi(name, info.mtime);
 
-	db_lock();
+	const ScopeDatabaseLock protect;
 	if (directory.playlists.UpdateOrInsert(std::move(pi)))
 		modified = true;
-	db_unlock();
 	return true;
 }
 
@@ -232,9 +228,11 @@ UpdateWalk::UpdateDirectoryChild(Directory &directory,
 					info.inode, info.device))
 			return;
 
-		db_lock();
-		Directory *subdir = directory.MakeChild(name);
-		db_unlock();
+		Directory *subdir;
+		{
+			const ScopeDatabaseLock protect;
+			subdir = directory.MakeChild(name);
+		}
 
 		assert(&directory == subdir->parent);
 
@@ -393,9 +391,11 @@ UpdateWalk::DirectoryMakeChildChecked(Directory &parent,
 				      const char *uri_utf8,
 				      const char *name_utf8)
 {
-	db_lock();
-	Directory *directory = parent.FindChild(name_utf8);
-	db_unlock();
+	Directory *directory;
+	{
+		const ScopeDatabaseLock protect;
+		directory = parent.FindChild(name_utf8);
+	}
 
 	if (directory != nullptr) {
 		if (directory->IsMount())
@@ -414,13 +414,14 @@ UpdateWalk::DirectoryMakeChildChecked(Directory &parent,
 
 	/* if we're adding directory paths, make sure to delete filenames
 	   with potentially the same name */
-	db_lock();
-	Song *conflicting = parent.FindSong(name_utf8);
-	if (conflicting)
-		editor.DeleteSong(parent, conflicting);
+	{
+		const ScopeDatabaseLock protect;
+		Song *conflicting = parent.FindSong(name_utf8);
+		if (conflicting)
+			editor.DeleteSong(parent, conflicting);
 
-	directory = parent.CreateChild(name_utf8);
-	db_unlock();
+		directory = parent.CreateChild(name_utf8);
+	}
 
 	directory_set_stat(*directory, info);
 	return directory;