         #endif
         
         var configuration2 = dbQueue1.configuration
-        configuration2.busyMode = .timeout(0.5)
+        configuration2.busyMode = .timeout(0.1)
         let dbQueue2 = try makeDatabaseQueue(filename: "test.sqlite", configuration: configuration2)
         
         let s1 = DispatchSemaphore(value: 0)
         let s2 = DispatchSemaphore(value: 0)
-        let queue = DispatchQueue(label: "GRDB", attributes: [.concurrent])
+        let queue = DispatchQueue.global()
         let group = DispatchGroup()
         
         queue.async(group: group) {

        
        let s1 = DispatchSemaphore(value: 0)
        let s2 = DispatchSemaphore(value: 0)
        let queue = DispatchQueue(label: "GRDB", attributes: [.concurrent])
        let group = DispatchGroup()
        
        queue.async(group: group) {

        #endif
        
        var configuration2 = dbQueue1.configuration
        configuration2.busyMode = .timeout(1)
        let dbQueue2 = try makeDatabaseQueue(filename: "test.sqlite", configuration: configuration2)
        
        let s1 = DispatchSemaphore(value: 0)
        let s2 = DispatchSemaphore(value: 0)
        let queue = DispatchQueue.global()
        let group = DispatchGroup()
        
        queue.async(group: group) {
            do {
                try dbQueue1.inTransaction(.exclusive) { db in
                    s2.signal()
                    queue.asyncAfter(deadline: .now() + 0.1) {
                        s1.signal()
                    }
                    _ = s1.wait(timeout: .distantFuture)
