9 files changed, 25 insertions, 12 deletions
diff --git a/src/db/Configured.cxx b/src/db/Configured.cxx
index 249a6e26e..5c0a1b00c 100644
--- a/src/db/Configured.cxx
+++ b/src/db/Configured.cxx
@@ -28,7 +28,7 @@
 #include "util/RuntimeError.hxx"
 
 Database *
-CreateConfiguredDatabase(EventLoop &main_event_loop,
+CreateConfiguredDatabase(EventLoop &main_event_loop, EventLoop &io_event_loop,
 			 DatabaseListener &listener)
 {
 	const auto *param = config_get_block(ConfigBlockOption::DATABASE);
@@ -39,12 +39,12 @@ CreateConfiguredDatabase(EventLoop &main_event_loop,
 					 param->line, path->line);
 
 	if (param != nullptr)
-		return DatabaseGlobalInit(main_event_loop,
+		return DatabaseGlobalInit(main_event_loop, io_event_loop,
 					  listener, *param);
 	else if (path != nullptr) {
 		ConfigBlock block(path->line);
 		block.AddBlockParam("path", path->value.c_str(), path->line);
-		return DatabaseGlobalInit(main_event_loop,
+		return DatabaseGlobalInit(main_event_loop, io_event_loop,
 					  listener, block);
 	} else {
 		/* if there is no override, use the cache directory */
@@ -61,7 +61,7 @@ CreateConfiguredDatabase(EventLoop &main_event_loop,
 
 		ConfigBlock block;
 		block.AddBlockParam("path", db_file_utf8.c_str(), -1);
-		return DatabaseGlobalInit(main_event_loop,
+		return DatabaseGlobalInit(main_event_loop, io_event_loop,
 					  listener, block);
 	}
 }
diff --git a/src/db/Configured.hxx b/src/db/Configured.hxx
index e2ba63ecc..287a40438 100644
--- a/src/db/Configured.hxx
+++ b/src/db/Configured.hxx
@@ -34,7 +34,7 @@ class Database;
  * Throws #std::runtime_error on error.
  */
 Database *
-CreateConfiguredDatabase(EventLoop &main_event_loop,
+CreateConfiguredDatabase(EventLoop &main_event_loop, EventLoop &io_event_loop,
 			 DatabaseListener &listener);
 
 #endif
diff --git a/src/db/DatabaseGlue.cxx b/src/db/DatabaseGlue.cxx
index c5cd02977..e3863119f 100644
--- a/src/db/DatabaseGlue.cxx
+++ b/src/db/DatabaseGlue.cxx
@@ -27,6 +27,7 @@
 
 Database *
 DatabaseGlobalInit(EventLoop &main_event_loop,
+		   EventLoop &io_event_loop,
 		   DatabaseListener &listener,
 		   const ConfigBlock &block)
 {
@@ -39,7 +40,8 @@ DatabaseGlobalInit(EventLoop &main_event_loop,
 					 plugin_name);
 
 	try {
-		return plugin->create(main_event_loop, listener, block);
+		return plugin->create(main_event_loop, io_event_loop,
+				      listener, block);
 	} catch (...) {
 		std::throw_with_nested(FormatRuntimeError("Failed to initialize database plugin '%s'",
 							  plugin_name));
diff --git a/src/db/DatabaseGlue.hxx b/src/db/DatabaseGlue.hxx
index 43b8e2a8f..19ab87345 100644
--- a/src/db/DatabaseGlue.hxx
+++ b/src/db/DatabaseGlue.hxx
@@ -36,6 +36,7 @@ class Database;
  */
 Database *
 DatabaseGlobalInit(EventLoop &main_event_loop,
+		   EventLoop &io_event_loop,
 		   DatabaseListener &listener,
 		   const ConfigBlock &block);
 
diff --git a/src/db/DatabasePlugin.hxx b/src/db/DatabasePlugin.hxx
index db486a0cb..ee58c0a3e 100644
--- a/src/db/DatabasePlugin.hxx
+++ b/src/db/DatabasePlugin.hxx
@@ -49,8 +49,11 @@ struct DatabasePlugin {
 	 *
 	 * @param main_event_loop the #EventLoop running in the same
 	 * thread which invokes #Database methods
+	 * @param io_event_loop the #EventLoop running on the
+	 * #EventThread, i.e. the one used for background I/O
 	 */
 	Database *(*create)(EventLoop &main_event_loop,
+			    EventLoop &io_event_loop,
 			    DatabaseListener &listener,
 			    const ConfigBlock &block);
 
diff --git a/src/db/plugins/ProxyDatabasePlugin.cxx b/src/db/plugins/ProxyDatabasePlugin.cxx
index c39a96fa2..aa532cad2 100644
--- a/src/db/plugins/ProxyDatabasePlugin.cxx
+++ b/src/db/plugins/ProxyDatabasePlugin.cxx
@@ -107,7 +107,9 @@ public:
 	ProxyDatabase(EventLoop &_loop, DatabaseListener &_listener,
 		      const ConfigBlock &block);
 
-	static Database *Create(EventLoop &loop, DatabaseListener &listener,
+	static Database *Create(EventLoop &main_event_loop,
+				EventLoop &io_event_loop,
+				DatabaseListener &listener,
 				const ConfigBlock &block);
 
 	void Open() override;
@@ -345,7 +347,8 @@ ProxyDatabase::ProxyDatabase(EventLoop &_loop, DatabaseListener &_listener,
 }
 
 Database *
-ProxyDatabase::Create(EventLoop &loop, DatabaseListener &listener,
+ProxyDatabase::Create(EventLoop &loop, EventLoop &,
+		      DatabaseListener &listener,
 		      const ConfigBlock &block)
 {
 	return new ProxyDatabase(loop, listener, block);
diff --git a/src/db/plugins/simple/SimpleDatabasePlugin.cxx b/src/db/plugins/simple/SimpleDatabasePlugin.cxx
index 2f72b4101..b2dbb4917 100644
--- a/src/db/plugins/simple/SimpleDatabasePlugin.cxx
+++ b/src/db/plugins/simple/SimpleDatabasePlugin.cxx
@@ -83,7 +83,7 @@ inline SimpleDatabase::SimpleDatabase(AllocatedPath &&_path,
 }
 
 Database *
-SimpleDatabase::Create(gcc_unused EventLoop &loop,
+SimpleDatabase::Create(EventLoop &, EventLoop &,
 		       gcc_unused DatabaseListener &listener,
 		       const ConfigBlock &block)
 {
diff --git a/src/db/plugins/simple/SimpleDatabasePlugin.hxx b/src/db/plugins/simple/SimpleDatabasePlugin.hxx
index 2f771dba7..c18b580eb 100644
--- a/src/db/plugins/simple/SimpleDatabasePlugin.hxx
+++ b/src/db/plugins/simple/SimpleDatabasePlugin.hxx
@@ -72,7 +72,9 @@ class SimpleDatabase : public Database {
 	SimpleDatabase(AllocatedPath &&_path, bool _compress);
 
 public:
-	static Database *Create(EventLoop &loop, DatabaseListener &listener,
+	static Database *Create(EventLoop &main_event_loop,
+				EventLoop &io_event_loop,
+				DatabaseListener &listener,
 				const ConfigBlock &block);
 
 	gcc_pure
diff --git a/src/db/plugins/upnp/UpnpDatabasePlugin.cxx b/src/db/plugins/upnp/UpnpDatabasePlugin.cxx
index 4a72b6d30..669bc37ef 100644
--- a/src/db/plugins/upnp/UpnpDatabasePlugin.cxx
+++ b/src/db/plugins/upnp/UpnpDatabasePlugin.cxx
@@ -75,7 +75,9 @@ class UpnpDatabase : public Database {
 public:
 	UpnpDatabase():Database(upnp_db_plugin) {}
 
-	static Database *Create(EventLoop &loop, DatabaseListener &listener,
+	static Database *Create(EventLoop &main_event_loop,
+				EventLoop &io_event_loop,
+				DatabaseListener &listener,
 				const ConfigBlock &block);
 
 	void Open() override;
@@ -138,7 +140,7 @@ private:
 };
 
 Database *
-UpnpDatabase::Create(gcc_unused EventLoop &loop,
+UpnpDatabase::Create(EventLoop &, EventLoop &,
 		     gcc_unused DatabaseListener &listener,
 		     const ConfigBlock &)
 {