#185 extra synchronization

jcabi · Nov 3, 2022 · 85ccf57 · 85ccf57
1 parent 8c91e37
commit 85ccf57
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Showing 2 changed files with 16 additions and 11 deletions.
diff --git a/src/main/java/com/jcabi/xml/XSLDocument.java b/src/main/java/com/jcabi/xml/XSLDocument.java
@@ -357,7 +357,9 @@ public String toString() {
     public XML transform(final XML xml) {
         final DocumentBuilder builder;
         try {
-            builder = XSLDocument.DFACTORY.newDocumentBuilder();
+            synchronized (XSLDocument.DFACTORY) {
+                builder = XSLDocument.DFACTORY.newDocumentBuilder();
+            }
         } catch (final ParserConfigurationException ex) {
             throw new IllegalArgumentException(
                 String.format(
@@ -397,15 +399,17 @@ public String applyTo(final XML xml) {
      * @param xml XML
      * @param result Result
      * @since 0.11
-     * @link https://stackoverflow.com/questions/4695489/capture-xslmessage-output-in-java
+     * @link <a href="https://stackoverflow.com/questions/4695489">Relevant SO question</a>
      */
     private void transformInto(final XML xml, final Result result) {
         final Transformer trans = this.transformer();
         final ConsoleErrorListener errors = new ConsoleErrorListener();
         trans.setErrorListener(errors);
         final long start = System.nanoTime();
         try {
-            trans.transform(new DOMSource(xml.node()), result);
+            synchronized (XSLDocument.DFACTORY) {
+                trans.transform(new DOMSource(xml.node()), result);
+            }
         } catch (final TransformerException ex) {
             throw new IllegalArgumentException(
                 String.format(
@@ -431,10 +435,10 @@ private void transformInto(final XML xml, final Result result) {
      * @return The transformer
      */
     private Transformer transformer() {
-        if (this.cached.get() == null) {
-            final Transformer trans;
-            synchronized (XSLDocument.TFACTORY) {
+        synchronized (XSLDocument.TFACTORY) {
+            if (this.cached.get() == null) {
                 XSLDocument.TFACTORY.setURIResolver(this.sources);
+                final Transformer trans;
                 try {
                     trans = XSLDocument.TFACTORY.newTransformer(
                         new StreamSource(new StringReader(this.xsl), this.sid)
@@ -448,11 +452,11 @@ private Transformer transformer() {
                         ex
                     );
                 }
+                for (final Map.Entry<String, Object> ent : this.params.entrySet()) {
+                    trans.setParameter(ent.getKey(), ent.getValue());
+                }
+                this.cached.set(XSLDocument.forSaxon(trans));
             }
-            for (final Map.Entry<String, Object> ent : this.params.entrySet()) {
-                trans.setParameter(ent.getKey(), ent.getValue());
-            }
-            this.cached.set(XSLDocument.forSaxon(trans));
         }
         return this.cached.get();
     }

diff --git a/src/test/java/com/jcabi/xml/XSLDocumentTest.java b/src/test/java/com/jcabi/xml/XSLDocumentTest.java
@@ -230,13 +230,14 @@ void transformsInManyThreads() throws Exception {
         );
         final AtomicInteger done = new AtomicInteger(0);
         final CountDownLatch latch = new CountDownLatch(1);
-        final int total = 10;
+        final int total = 50;
         final ExecutorService exec = Executors.newFixedThreadPool(total);
         for (int task = 0; task < total; ++task) {
             exec.submit(
                 () -> {
                     latch.await();
                     xsl.transform(xml);
+                    xsl.transform(xml);
                     done.incrementAndGet();
                     return 0;
                 }