Author: markt
Date: Tue Aug 11 20:34:00 2015
New Revision: 1695371
URL: http://svn.apache.org/r1695371
Log:
Fix possible cause of intermittent CI failures and bug 58157
Modified:
tomcat/trunk/java/org/apache/catalina/core/AsyncContextImpl.java
Modified: tomcat/trunk/java/org/apache/catalina/core/AsyncContextImpl.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/AsyncContextImpl.java?rev=1695371&r1=1695370&r2=1695371&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/core/AsyncContextImpl.java (original)
+++ tomcat/trunk/java/org/apache/catalina/core/AsyncContextImpl.java Tue Aug 11
20:34:00 2015
@@ -58,6 +58,15 @@ public class AsyncContextImpl implements
protected static final StringManager sm =
StringManager.getManager(Constants.Package);
+ /* When a request uses a sequence of multiple start(); dispatch() with
+ * non-container threads it is possible for a previous dispatch() to
+ * interfere with a following start(). This lock prevents that from
+ * happening. It is a dedicated object as user code may lock on the
+ * AsyncContext so if container code also locks on that object deadlocks
may
+ * occur.
+ */
+ private final Object asyncContextLock = new Object();
+
private volatile ServletRequest servletRequest = null;
private volatile ServletResponse servletResponse = null;
private final List<AsyncListenerWrapper> listeners = new ArrayList<>();
@@ -180,46 +189,48 @@ public class AsyncContextImpl implements
@Override
public void dispatch(ServletContext context, String path) {
- if (log.isDebugEnabled()) {
- logDebug("dispatch ");
- }
- check();
- if (dispatch != null) {
- throw new IllegalStateException(
- sm.getString("asyncContextImpl.dispatchingStarted"));
- }
- if (request.getAttribute(ASYNC_REQUEST_URI)==null) {
- request.setAttribute(ASYNC_REQUEST_URI, request.getRequestURI());
- request.setAttribute(ASYNC_CONTEXT_PATH, request.getContextPath());
- request.setAttribute(ASYNC_SERVLET_PATH, request.getServletPath());
- request.setAttribute(ASYNC_PATH_INFO, request.getPathInfo());
- request.setAttribute(ASYNC_QUERY_STRING, request.getQueryString());
- }
- final RequestDispatcher requestDispatcher =
context.getRequestDispatcher(path);
- if (!(requestDispatcher instanceof AsyncDispatcher)) {
- throw new UnsupportedOperationException(
- sm.getString("asyncContextImpl.noAsyncDispatcher"));
- }
- final AsyncDispatcher applicationDispatcher =
- (AsyncDispatcher) requestDispatcher;
- final ServletRequest servletRequest = getRequest();
- final ServletResponse servletResponse = getResponse();
- Runnable run = new Runnable() {
- @Override
- public void run() {
- request.getCoyoteRequest().action(ActionCode.ASYNC_DISPATCHED,
null);
- try {
- applicationDispatcher.dispatch(servletRequest,
servletResponse);
- }catch (Exception x) {
- //log.error("Async.dispatch",x);
- throw new RuntimeException(x);
- }
+ synchronized (asyncContextLock) {
+ if (log.isDebugEnabled()) {
+ logDebug("dispatch ");
}
- };
+ check();
+ if (dispatch != null) {
+ throw new IllegalStateException(
+ sm.getString("asyncContextImpl.dispatchingStarted"));
+ }
+ if (request.getAttribute(ASYNC_REQUEST_URI)==null) {
+ request.setAttribute(ASYNC_REQUEST_URI,
request.getRequestURI());
+ request.setAttribute(ASYNC_CONTEXT_PATH,
request.getContextPath());
+ request.setAttribute(ASYNC_SERVLET_PATH,
request.getServletPath());
+ request.setAttribute(ASYNC_PATH_INFO, request.getPathInfo());
+ request.setAttribute(ASYNC_QUERY_STRING,
request.getQueryString());
+ }
+ final RequestDispatcher requestDispatcher =
context.getRequestDispatcher(path);
+ if (!(requestDispatcher instanceof AsyncDispatcher)) {
+ throw new UnsupportedOperationException(
+ sm.getString("asyncContextImpl.noAsyncDispatcher"));
+ }
+ final AsyncDispatcher applicationDispatcher =
+ (AsyncDispatcher) requestDispatcher;
+ final ServletRequest servletRequest = getRequest();
+ final ServletResponse servletResponse = getResponse();
+ Runnable run = new Runnable() {
+ @Override
+ public void run() {
+
request.getCoyoteRequest().action(ActionCode.ASYNC_DISPATCHED, null);
+ try {
+ applicationDispatcher.dispatch(servletRequest,
servletResponse);
+ }catch (Exception x) {
+ //log.error("Async.dispatch",x);
+ throw new RuntimeException(x);
+ }
+ }
+ };
- this.dispatch = run;
- this.request.getCoyoteRequest().action(ActionCode.ASYNC_DISPATCH,
null);
- clearServletRequestResponse();
+ this.dispatch = run;
+ this.request.getCoyoteRequest().action(ActionCode.ASYNC_DISPATCH,
null);
+ clearServletRequestResponse();
+ }
}
@Override
@@ -332,25 +343,27 @@ public class AsyncContextImpl implements
public void setStarted(Context context, ServletRequest request,
ServletResponse response, boolean originalRequestResponse) {
- this.request.getCoyoteRequest().action(
- ActionCode.ASYNC_START, this);
-
- this.context = context;
- this.servletRequest = request;
- this.servletResponse = response;
- this.hasOriginalRequestAndResponse = originalRequestResponse;
- this.event = new AsyncEvent(this, request, response);
-
- List<AsyncListenerWrapper> listenersCopy = new ArrayList<>();
- listenersCopy.addAll(listeners);
- listeners.clear();
- for (AsyncListenerWrapper listener : listenersCopy) {
- try {
- listener.fireOnStartAsync(event);
- } catch (Throwable t) {
- ExceptionUtils.handleThrowable(t);
- log.warn("onStartAsync() failed for listener of type [" +
- listener.getClass().getName() + "]", t);
+ synchronized (asyncContextLock) {
+ this.request.getCoyoteRequest().action(
+ ActionCode.ASYNC_START, this);
+
+ this.context = context;
+ this.servletRequest = request;
+ this.servletResponse = response;
+ this.hasOriginalRequestAndResponse = originalRequestResponse;
+ this.event = new AsyncEvent(this, request, response);
+
+ List<AsyncListenerWrapper> listenersCopy = new ArrayList<>();
+ listenersCopy.addAll(listeners);
+ listeners.clear();
+ for (AsyncListenerWrapper listener : listenersCopy) {
+ try {
+ listener.fireOnStartAsync(event);
+ } catch (Throwable t) {
+ ExceptionUtils.handleThrowable(t);
+ log.warn("onStartAsync() failed for listener of type [" +
+ listener.getClass().getName() + "]", t);
+ }
}
}
}
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