Fixes #5498 ServletHolder cleanup (#5514)

* Fixes #55498 ServletHolder cleanup Various cleanups for #5498 including: + renaming multiple `_servlet` fields in inner classes to avoid confusion + better comments in prepare method to describe why it is needed + call prepare from Invoker servlet + The `_servlet` field is not set until after the servlet is initialized + Consistent wrapping of `SingleThreadedWrapper` now in `initServlet` + The `getServlet` method now looks the volatile `_servlet` to avoid locking if possible + The `handle` method now calls `getServletInstance` as servlet will have been initialized in `prepare` + Found and fixed race with making unavaiable servlet available again + fixed nanotime overflow + fixed several compiler warnings/suggestions + removed while true from unavailable servlet + Do not destroy servlets unless init has been called. + Added TODOs about calling predestroy on instances not created by the holder. + Do not destroy servlets unless init has been called. + Added TODOs about calling predestroy on instances not created by the holder. + improved dump and toString
jetty · Oct 28, 2020 · 7a0de6a · 7a0de6a
1 parent b3186a9
commit 7a0de6a
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Showing 8 changed files with 141 additions and 120 deletions.
diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/DefaultServlet.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/DefaultServlet.java
@@ -149,7 +149,6 @@ public class DefaultServlet extends HttpServlet implements ResourceFactory, Welc
     private boolean _useFileMappedBuffer = false;
     private String _relativeResourceBase;
     private ServletHandler _servletHandler;
-    private ServletHolder _defaultHolder;
 
     public DefaultServlet(ResourceService resourceService)
     {
@@ -303,11 +302,6 @@ public void init()
         _resourceService.setGzipEquivalentFileExtensions(gzipEquivalentFileExtensions);
 
         _servletHandler = _contextHandler.getChildHandlerByClass(ServletHandler.class);
-        for (ServletHolder h : _servletHandler.getServlets())
-        {
-            if (h.getServletInstance() == this)
-                _defaultHolder = h;
-        }
 
         if (LOG.isDebugEnabled())
             LOG.debug("resource base = " + _resourceBase);
@@ -504,19 +498,17 @@ public String getWelcomeFile(String pathInContext)
             return null;
 
         String welcomeServlet = null;
-        for (int i = 0; i < _welcomes.length; i++)
+        for (String s : _welcomes)
         {
-            String welcomeInContext = URIUtil.addPaths(pathInContext, _welcomes[i]);
+            String welcomeInContext = URIUtil.addPaths(pathInContext, s);
             Resource welcome = getResource(welcomeInContext);
             if (welcome != null && welcome.exists())
                 return welcomeInContext;
 
             if ((_welcomeServlets || _welcomeExactServlets) && welcomeServlet == null)
             {
                 MappedResource<ServletHolder> entry = _servletHandler.getMappedServlet(welcomeInContext);
-                @SuppressWarnings("ReferenceEquality")
-                boolean isDefaultHolder = (entry.getResource() != _defaultHolder);
-                if (entry != null && isDefaultHolder &&
+                if (entry != null && entry.getResource().getServletInstance() != this &&
                     (_welcomeServlets || (_welcomeExactServlets && entry.getPathSpec().getDeclaration().equals(welcomeInContext))))
                     welcomeServlet = welcomeInContext;
             }

diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/FilterHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/FilterHolder.java
@@ -222,7 +222,8 @@ public void dump(Appendable out, String indent) throws IOException
     @Override
     public String toString()
     {
-        return String.format("%s@%x==%s,inst=%b,async=%b", getName(), hashCode(), getClassName(), _filter != null, isAsyncSupported());
+        return String.format("%s==%s@%x{inst=%b,async=%b,src=%s}",
+            getName(), getClassName(), hashCode(), _filter != null, isAsyncSupported(), getSource());
     }
 
     public FilterRegistration.Dynamic getRegistration()

diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/Invoker.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/Invoker.java
@@ -231,6 +231,7 @@ protected void service(HttpServletRequest request, HttpServletResponse response)
         if (holder != null)
         {
             final Request baseRequest = Request.getBaseRequest(request);
+            holder.prepare(baseRequest, request, response);
             holder.handle(baseRequest,
                 new InvokedRequest(request, included, servlet, servletPath, pathInfo),
                 response);

diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ListenerHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ListenerHolder.java
@@ -126,7 +126,7 @@ public void doStop() throws Exception
     @Override
     public String toString()
     {
-        return super.toString() + ": " + getClassName();
+        return String.format("%s@%x{src=%s}", getClassName(), hashCode(), getSource());
     }
 
     /**