fix to swing update manager

Ghidra/Framework/Generic/src/main/java/ghidra/util/task/SwingUpdateManager.java

@@ -138,7 +138,7 @@ public class SwingUpdateManager {
 
 		recordInception();
 		this.minDelay = Math.max(MIN_DELAY_FLOOR, minDelay);
-		timer = new Timer(minDelay, e -> checkForWork());
+		timer = new Timer(minDelay, e -> timerCallback());
 		timer.setRepeats(false);
 		instances.add(this);
 	}
@@ -261,12 +261,23 @@ public class SwingUpdateManager {
 		}
 	}
 
+	// This is similar to checkForWork except that it resets the task buffering when
+	// the time expires and there is no work to do.
+	private void timerCallback() {
+
+		if (shouldDoWork()) {
+			doWork();
+		}
+		else if (requestTime == NONE) {
+			bufferingStartTime = NONE; // The timer has fired and there is no pending work
+		}
+	}
+
 	// note: this is called on the Swing thread
 	private synchronized boolean shouldDoWork() {
 
 		// If no pending request, exit without restarting timer
 		if (requestTime == NONE) {
-			bufferingStartTime = NONE; // The timer has fired and there is no pending work
 			return false;
 		}
 

Ghidra/Framework/Generic/src/test/java/ghidra/util/task/SwingUpdateManagerTimerTest.java

@@ -0,0 +1,86 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.util.task;
+
+import static org.junit.Assert.*;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import generic.test.AbstractGenericTest;
+import ghidra.util.Msg;
+import ghidra.util.SystemUtilities;
+
+public class SwingUpdateManagerTimerTest extends AbstractGenericTest {
+	private static final int MIN_DELAY = 100;
+	private static final int MAX_DELAY = 10000;
+	private volatile int runnableCalled;
+	private SwingUpdateManager manager;
+
+	@Before
+	public void setUp() throws Exception {
+		manager = createUpdateManager(MIN_DELAY, MAX_DELAY);
+
+		// must turn this on to get the expected results, as in headless mode the update manager
+		// will run it's Swing work immediately on the test thread, which is not true to the
+		// default behavior
+		System.setProperty(SystemUtilities.HEADLESS_PROPERTY, Boolean.FALSE.toString());
+	}
+
+	@Test
+	public void testNotFiringTooOften() throws InterruptedException {
+		Thread t = new Thread(() -> {
+			for (int i = 0; i < 50; i++) {
+				manager.update();
+				manager.update();
+				manager.update();
+				manager.update();
+				sleep(10);
+			}
+		});
+		t.start();
+		t.join();
+		waitForManager();
+		assertEquals(2, runnableCalled);
+	}
+
+//==================================================================================================
+// Private Methods
+//==================================================================================================
+	private void waitForManager() {
+
+		// let all swing updates finish, which may trigger the update manager
+		waitForSwing();
+
+		while (manager.isBusy()) {
+			sleep(DEFAULT_WAIT_DELAY);
+		}
+
+		// let any resulting swing events finish
+		waitForSwing();
+	}
+
+	private SwingUpdateManager createUpdateManager(int min, int max) {
+		return new SwingUpdateManager(min, max, "bob", new Runnable() {
+
+			@Override
+			public void run() {
+				runnableCalled++;
+				Msg.debug(this, "run() called - count: " + runnableCalled);
+			}
+		});
+	}
+}