Merge pull request #839 from MarcMil/faster-sysclass

Summaries: Cache the XMLInputFactory

Author: StevenArzt

soot-infoflow-summaries/src/soot/jimple/infoflow/methodSummary/xml/SummaryReader.java

@@ -18,6 +18,7 @@
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -55,6 +56,30 @@ private enum State {
 		summary, hierarchy, intf, methods, method, flow, clear, gaps, gap, constraints, key, index
 	}
 
+	/**
+	 * It takes quite a while to create a new XML Input Factory 
+	 */
+	private static class CachedFactory {
+		WeakReference<Thread> thread;
+		XMLInputFactory factory;
+
+		public CachedFactory() {
+
+			XMLInputFactory factory = XMLInputFactory.newInstance();
+			factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
+			factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
+			this.factory = factory;
+			this.thread = new WeakReference<Thread>(Thread.currentThread());
+		}
+
+		public boolean isValidForThisThread() {
+			Thread thr = thread.get();
+			return Thread.currentThread() == thr;
+		}
+	}
+
+	private CachedFactory cachedFactory;
+
 	/**
 	 * Reads a summary xml and places the new summaries into the given data object.
 	 * This method closes the reader.
@@ -68,10 +93,13 @@ public void read(Reader reader, ClassMethodSummaries summaries)
 			throws XMLStreamException, SummaryXMLException, IOException {
 		XMLStreamReader xmlreader = null;
 		try {
-			XMLInputFactory factory = XMLInputFactory.newInstance();
-			factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
-			factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
-			xmlreader = factory.createXMLStreamReader(reader);
+			//Sadly, the XML Input Factory is not thread safe :/
+			CachedFactory cachedFact = cachedFactory;
+			if (cachedFact == null || !cachedFact.isValidForThisThread()) {
+				cachedFact = new CachedFactory();
+				this.cachedFactory = cachedFact;
+			}
+			xmlreader = cachedFact.factory.createXMLStreamReader(reader);
 			final MethodSummaries summary = summaries.getMethodSummaries();
 
 			Map<String, String> sourceAttributes = new HashMap<String, String>();

soot-infoflow/src/soot/jimple/infoflow/AbstractInfoflow.java

@@ -1257,6 +1257,7 @@ else if (reason instanceof TimeoutReason)
 				performanceData.updateMaxMemoryConsumption(getUsedMemory());
 				logger.info(String.format("Memory consumption after cleanup: %d MB", getUsedMemory()));
 
+				beforePathReconstruction = System.nanoTime();
 				// Reconstruct the paths from source to sink
 				reconstructPaths(builder, resultExecutor, res);
 			} finally {
@@ -1339,6 +1340,9 @@ else if (logger.isInfoEnabled()) {
 	 */
 	protected void reconstructPaths(IAbstractionPathBuilder builder, InterruptableExecutor executor,
 			Set<AbstractionAtSink> ifdsResults) {
+		if (ifdsResults.isEmpty())
+			return;
+
 		FlowDroidTimeoutWatcher pathTimeoutWatcher = null;
 
 		try {