Unit tests for XmlRpcDispatch (#1232)

* Unit tests for XmlRpcDispatch

* Fix handling of out-of-band (Exception) request and and event
processing to match previous select() implementation.
* Update comments to describe the events that actually trigger and
Exception state.
* Unit tests for XmlRpcDispatch to verify that it calls poll()
correctly, requests the correct events and calls the correct handler
for those events.

* Cleanup from internal review

* revert unnecessary whitespace changes

utilities/xmlrpcpp/include/xmlrpcpp/XmlRpcDispatch.h

@@ -31,7 +31,7 @@ namespace XmlRpc {
     enum EventType {
       ReadableEvent = 1,    //!< data available to read
       WritableEvent = 2,    //!< connected/data can be written without blocking
-      Exception     = 4     //!< uh oh
+      Exception     = 4     //!< out-of-band data has arrived
     };
 
     //! Monitor this source for the event types specified by the event mask

utilities/xmlrpcpp/src/XmlRpcDispatch.cpp

@@ -85,7 +85,8 @@ XmlRpcDispatch::work(double timeout)
   const unsigned POLLIN_CHK = (POLLIN | POLLHUP | POLLERR); // Readable or connection lost
   const unsigned POLLOUT_REQ = POLLOUT; // Request write
   const unsigned POLLOUT_CHK = (POLLOUT | POLLERR); // Writable or connection lost
-  const unsigned POLLEX_CHK = (POLLPRI | POLLNVAL); // Exception or invalid fd
+  const unsigned POLLEX_REQ = POLLPRI; // Out-of-band data received
+  const unsigned POLLEX_CHK = (POLLPRI | POLLNVAL); // Out-of-band data or invalid fd
 
   // Compute end time
   _endTime = (timeout < 0.0) ? -1.0 : (getTime() + timeout);
@@ -110,6 +111,7 @@ XmlRpcDispatch::work(double timeout)
       fds[i].events = 0;
       if (it->getMask() & ReadableEvent) fds[i].events |= POLLIN_REQ;
       if (it->getMask() & WritableEvent) fds[i].events |= POLLOUT_REQ;
+      if (it->getMask() & Exception) fds[i].events |= POLLEX_REQ;
     }
 
     // Check for events
@@ -132,11 +134,12 @@ XmlRpcDispatch::work(double timeout)
       // Only handle requested events to avoid being prematurely removed from dispatch
       bool readable = (pfd.events & POLLIN_REQ) == POLLIN_REQ;
       bool writable = (pfd.events & POLLOUT_REQ) == POLLOUT_REQ;
+      bool oob = (pfd.events & POLLEX_REQ) == POLLEX_REQ;
       if (readable && (pfd.revents & POLLIN_CHK))
         newMask &= src->handleEvent(ReadableEvent);
       if (writable && (pfd.revents & POLLOUT_CHK))
         newMask &= src->handleEvent(WritableEvent);
-      if (pfd.revents & POLLEX_CHK)
+      if (oob && (pfd.revents & POLLEX_CHK))
         newMask &= src->handleEvent(Exception);
 
       // Find the source iterator. It may have moved as a result of the way

utilities/xmlrpcpp/test/CMakeLists.txt

@@ -17,6 +17,20 @@ catkin_add_gtest(test_client
 )
 target_link_libraries(test_client mock_socket)
 
+catkin_add_gtest(test_dispatch
+  test_dispatch.cpp
+  ../src/XmlRpcDispatch.cpp
+  ../src/XmlRpcSource.cpp
+  ../src/XmlRpcUtil.cpp
+  ../libb64/src/cdecode.c
+  ../libb64/src/cencode.c
+)
+target_link_libraries(test_dispatch mock_socket)
+set_target_properties(test_dispatch PROPERTIES
+  LINK_FLAGS
+  "-Wl,--wrap=select -Wl,--wrap=poll"
+)
+
 if(NOT WIN32)
   catkin_add_gtest(test_socket
     test_socket.cpp