public Servlet getServlet() throws ServletException, IOException, FileNotFoundException { if (reload) { synchronized (this) { // Synchronizing on jsw enables simultaneous loading // of different pages, but not the same page. if (reload) { // This is to maintain the original protocol. destroy(); try { servletClass = ctxt.load(); theServlet = (Servlet) servletClass.newInstance(); } catch (IllegalAccessException ex1) { throw new JasperException(ex1); } catch (InstantiationException ex) { throw new JasperException(ex); } theServlet.init(config); firstTime = false; reload = false; } } } return theServlet; }
public Servlet getServlet() throws ServletException { // DCL on 'reload' requires that 'reload' be volatile // (this also forces a read memory barrier, ensuring the // new servlet object is read consistently) if (reload) { synchronized (this) { // Synchronizing on jsw enables simultaneous loading // of different pages, but not the same page. if (reload) { // This is to maintain the original protocol. destroy(); final Servlet servlet; try { InstanceManager instanceManager = InstanceManagerFactory.getInstanceManager(config); servlet = (Servlet) instanceManager.newInstance(ctxt.getFQCN(), ctxt.getJspLoader()); } catch (IllegalAccessException e) { throw new JasperException(e); } catch (InstantiationException e) { throw new JasperException(e); } catch (Exception e) { throw new JasperException(e); } servlet.init(config); if (!firstTime) { ctxt.getRuntimeContext().incrementJspReloadCount(); } theServlet = servlet; reload = false; // Volatile 'reload' forces in order write of 'theServlet' and new servlet object } } } return theServlet; }