#vulnerable code 
                                @Test
    public void basicBusyHandler() throws Exception {
        final int[] calls = {0};
        BusyHandler.setHandler(conn, new BusyHandler() {
            @Override
            protected int callback(int nbPrevInvok) throws SQLException {
                assertEquals(nbPrevInvok, calls[0]);
                calls[0]++;

                if (nbPrevInvok <= 1) {
                    return 1;
                } else {
                    return 0;
                }
            }
        });

        BusyWork busyWork = new BusyWork();
        busyWork.start();

        // I let busyWork prepare a huge insert
        Thread.sleep(1000);

        synchronized(busyWork){
            try{
                workWork();
            } catch(SQLException ex) {
                assertEquals(SQLiteErrorCode.SQLITE_BUSY.code, ex.getErrorCode());
            }
        }

        busyWork.interrupt();
        assertEquals(3, calls[0]);
    } 
                            #location 4 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                @Test
    public void basicBusyHandler() throws Exception {
        final int[] calls = {0};
        BusyHandler.setHandler(conn, new BusyHandler() {
            @Override
            protected int callback(int nbPrevInvok) throws SQLException {
                assertEquals(nbPrevInvok, calls[0]);
                calls[0]++;

                if (nbPrevInvok <= 1) {
                    return 1;
                } else {
                    return 0;
                }
            }
        });

        BusyWork busyWork = new BusyWork();
        busyWork.start();

        // let busyWork block inside insert
        busyWork.lockedLatch.await();

        try{
            workWork();
            fail("Should throw SQLITE_BUSY exception");
        } catch(SQLException ex) {
            assertEquals(SQLiteErrorCode.SQLITE_BUSY.code, ex.getErrorCode());
        }

        busyWork.completeLatch.countDown();
        busyWork.join();
        assertEquals(3, calls[0]);
    }