FileDescriptorActivity: fix unit test failure related to almost concu…

…rrent removal of watched fd and write Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
orocos-toolchain · Oct 24, 2019 · 96eced7 · 96eced7
1 parent 03e8b76
commit 96eced7
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Showing 2 changed files with 29 additions and 4 deletions.
diff --git a/rtt/extras/FileDescriptorActivity.cpp b/rtt/extras/FileDescriptorActivity.cpp
@@ -389,14 +389,36 @@ void FileDescriptorActivity::loop()
             oro_atomic_set(&m_trigger, 0);
             do_trigger = true;
         }
+        if (oro_atomic_read(&m_update_sets) > 0) {
+            oro_atomic_set(&m_update_sets, 0);
+
+            // Check if file descriptors that have work also have been removed in the current cycle and
+            // already ignore them. This is a corner case and still triggering an IOReady event would
+            // probably be fine in real-world applications, but it can break the task-test unit test
+            // depending on timing.
+            //
+            // The simple solution would be to continue without triggering the component, but we might miss
+            // triggers or activities on other file descriptors then.
+            //
+            // Disabled for now and patched in the unit test.
+            //
+//            { RTT::os::MutexLock lock(m_fd_lock);
+//                fd_set copy;
+//                FD_ZERO(&copy);
+//                m_has_ioready = false;
+//                for(int i = 0; i <= max_fd; ++i) {
+//                    if (FD_ISSET(i, &m_fd_set) && FD_ISSET(i, &m_fd_work)) {
+//                        FD_SET(i, &copy);
+//                        m_has_ioready = true;
+//                    }
+//                }
+//                m_fd_work = copy;
+//            }
+        }
         if (oro_atomic_read(&m_break_loop) > 0) {
             oro_atomic_set(&m_break_loop, 0);
             break;
         }
-        if (oro_atomic_read(&m_update_sets) > 0) {
-            oro_atomic_set(&m_update_sets, 0);
-            continue;
-        }
 
         // Execute activity...
         if (m_has_timeout || m_has_ioready || do_trigger)

diff --git a/tests/taskthread_fd_test.cpp b/tests/taskthread_fd_test.cpp
@@ -218,6 +218,9 @@ BOOST_AUTO_TEST_CASE(testFileDescriptor_Write )
 	mtask->unwatch(mcomp.fd[0]);
     BOOST_CHECK( mtask->isWatched(mcomp.fd[0]) == false );
 
+    // sleep to give the FileDescriptorActivity some time to update the internal file descriptor set
+    usleep(100000/10);
+
 	++ch;
 	rc = write(mcomp.fd[1], &ch, sizeof(ch));
 	if (1 != rc) std::cerr << "rc=" << rc << " errno=" << errno << ":" << strerror(errno) << std::endl;